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    MC9S12XS256 Reference Manual Covers MC9S12XS-Family MC9S12XS256 MC9S12XS128 MC9S12XS64 S12XS Microcontrollers MC9S12XS256RMV1 Rev. 1.03 06/2008 freescale.com To provide the most up-to-date information, the document revision on the World Wide Web is the most current. A printed copy may be an earlier revision. To verify you have the latest information available, refer to: http://freescale.com/ This document contains information for the complete S12XS-Family and thus includes a set of separate flash (FTMR) module sections to cover the whole family. A full list of family members and options is included in the appendices. This document contains information for all constituent modules, with the exception of the CPU. For CPU information please refer to CPU12XV1 in the CPU12/CPU12X Reference Manual. Revision History Date May, 2007 August, 2007 February, 2008 Revision Level 1.00 1.01 1.02 Description Initial version - PRELIMINARY Corrected CPU documentation reference in above paragraph Updated chp. ‘256 KByte Flash Module’ - see ‘FTMR256K1 Revision History’ Updated chp. ‘128 KByte Flash Module’ - see ‘FTMR128K1 Revision History’ Updated chp. ‘Port Integration Module’ - see ‘Revision History’ Unburied tag of chp. 16 ‘Timer Module (TIM16B8CV2)’ Removed subject-to-change note on pinouts in figs. 1-3 to 1-5 Changed ‘drive’ to ‘output’ of ECLK on PE4 in 1.2.3.10 for clarity Added 1M04M mask revision to table 1-3 Corrected description of ESD diode connections in A.1.2 Updated Thermal Package Characteristics in table A-5 Added XIRQ pulse width to table A-6 and A-7 Made 64-pin package drawing visible in fig. B-3 Corrected PWM channel numbers in table D-2 Several corrections in E.1 ‘Detailed Register Map’ Minor cosmetic corrections Added document order number to cover, changed title, updated backcover Updated CPU version in above paragraph according to new CPU manual Corrected number of SPI and SCI modules in Features Corrected SPI pins on routed Port M locations in Detailed Signal Descriptions Reset Sources and Interrupt Vector Locations tables updated Updated FTMR, XMMC, PIM, TIM, VREG, XDBG and XINT sections Added Temperature Sensor Configuration section Updated several tables in Appendix A Added NVM timing characteristics Updated VREG electrical characteristics Updated mechanical package drawings Revision History (continued) Date June, 2008 Revision Level 1.03 Description Corrected SPI0 pins in family block diagram and Detailed Signal Descriptions Corrected descriptions of pins PM2,3,5 in Pin-out Summary table Added general application note at beginning of Detailed Signal Descriptions Updated ADC, PIM, XDBG, and CRG sections Added FTM64K1 section Added/updated max. Idd limits in Appx. A Added ATD min./max. values to electrical characteristics in Appx. A Added ATD min./max. values to conversion performance in Appx. A Added jitter fit parameter in Appx. A Updated several parameter classifications in Appx. A Updated several VREG electricals in Appx. A Corrected bit names in Appx. E S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 3 S12XS-Family Reference Manual, Rev. 1.03 4 PRELIMINARY Freescale Semiconductor Chapter 1 Chapter 2 Chapter 3 Chapter 4 Chapter 5 Chapter 6 Chapter 7 Chapter 8 Chapter 9 Chapter 10 Chapter 11 Chapter 12 Chapter 13 Chapter 14 Chapter 15 Chapter 16 Chapter 17 Chapter 18 Chapter 19 Chapter 20 Appendix A Appendix B Appendix C Appendix D Appendix E Appendix F Device Overview S12XS-Family . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17 Port Integration Module (S12XSPIMV1) . . . . . . . . . . . . . . . . . . . . . . . . . . .55 Memory Mapping Control (S12XMMCV4) . . . . . . . . . . . . . . . . . . . . . . . .121 Interrupt (S12XINTV2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .145 Background Debug Module (S12XBDMV2) . . . . . . . . . . . . . . . . . . . . . . .161 S12X Debug (S12XDBGV3) Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . .187 Security (S12XS9SECV2). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .223 S12XE Clocks and Reset Generator (S12XECRGV1) . . . . . . . . . . . . . . .229 Pierce Oscillator (S12XOSCLCPV2) . . . . . . . . . . . . . . . . . . . . . . . . . . . .263 Analog-to-Digital Converter (ADC12B16CV1) . . . . . . . . . . . . . . . . . . . . .267 Freescale’s Scalable Controller Area Network (S12MSCANV3) . . . . . .293 Periodic Interrupt Timer (S12PIT24B4CV1) . . . . . . . . . . . . . . . . . . . . . . .349 Pulse-Width Modulator (S12PWM8B8CV1) . . . . . . . . . . . . . . . . . . . . . . .365 Serial Communication Interface (S12SCIV5) . . . . . . . . . . . . . . . . . . . . . .397 Serial Peripheral Interface (S12SPIV5) . . . . . . . . . . . . . . . . . . . . . . . . . . .435 Timer Module (TIM16B8CV2). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .461 Voltage Regulator (S12VREGL3V3V1) . . . . . . . . . . . . . . . . . . . . . . . . . . .489 256 KByte Flash Module (S12XFTMR256K1V1). . . . . . . . . . . . . . . . . . . .507 128 KByte Flash Module (S12XFTMR128K1V1). . . . . . . . . . . . . . . . . . . .565 64 KByte Flash Module (S12XFTMR64K1V1). . . . . . . . . . . . . . . . . . . . . .623 Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .679 Package Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .719 PCB Layout Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .729 Derivative Differences . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .733 Detailed Register Address Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .734 Ordering Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .756 S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 1 S12XS-Family Reference Manual, Rev. 1.03 2 PRELIMINARY Freescale Semiconductor Chapter 1 Device Overview S12XS-Family 1.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 1.1.1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 1.1.2 Modes of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 1.1.3 Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 1.1.4 Device Memory Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 1.1.5 Address Mapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 1.1.6 Detailed Register Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 1.1.7 Part ID Assignments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 1.2 Signal Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 1.2.1 Device Pinout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 1.2.2 Pin Assignment Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 1.2.3 Detailed Signal Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 1.2.4 Power Supply Pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 1.3 System Clock Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 1.4 Modes of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 1.4.1 Chip Configuration Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 1.4.2 Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 1.4.3 Freeze Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 1.5 Security . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 1.6 Resets and Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 1.6.1 Resets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 1.6.2 Vectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 1.6.3 Effects of Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 1.7 ATD0 Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 1.7.1 External Trigger Input Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 1.7.2 ATD0 Channel[17] Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 1.8 VREG Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 1.8.1 Temperature Sensor Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 1.9 Oscillator Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 Chapter 2 Port Integration Module (S12XSPIMV1) 2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 2.1.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 2.1.2 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 2.2 External Signal Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 2.3 Memory Map and Register Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 2.3.1 Memory Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 3 2.3.2 Register Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 2.3.3 Port A Data Register (PORTA) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 2.3.4 Port B Data Register (PORTB) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 2.3.5 Port A Data Direction Register (DDRA) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71 2.3.6 Port B Data Direction Register (DDRB) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71 2.3.7 PIM Reserved Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72 2.3.8 Port E Data Register (PORTE) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72 2.3.9 Port E Data Direction Register (DDRE) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73 2.3.10 Ports ABEK, BKGD pin Pull-up Control Register (PUCR) . . . . . . . . . . . . . . . . . . . . . . 74 2.3.11 Ports ABEK Reduced Drive Register (RDRIV) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75 2.3.12 ECLK Control Register (ECLKCTL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76 2.3.13 PIM Reserved Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77 2.3.14 IRQ Control Register (IRQCR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78 2.3.15 PIM Reserved Register PIMTEST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78 2.3.16 Port K Data Register (PORTK) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79 2.3.17 Port K Data Direction Register (DDRK) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79 2.3.18 Port T Data Register (PTT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80 2.3.19 Port T Input Register (PTIT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81 2.3.20 Port T Data Direction Register (DDRT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81 2.3.21 Port T Reduced Drive Register (RDRT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82 2.3.22 Port T Pull Device Enable Register (PERT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83 2.3.23 Port T Polarity Select Register (PPST) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83 2.3.24 PIM Reserved Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84 2.3.25 Port T Routing Register (PTTRR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84 2.3.26 Port S Data Register (PTS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85 2.3.27 Port S Input Register (PTIS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 2.3.28 Port S Data Direction Register (DDRS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 2.3.29 Port S Reduced Drive Register (RDRS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88 2.3.30 Port S Pull Device Enable Register (PERS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89 2.3.31 Port S Polarity Select Register (PPSS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89 2.3.32 Port S Wired-Or Mode Register (WOMS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90 2.3.33 PIM Reserved Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90 2.3.34 Port M Data Register (PTM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91 2.3.35 Port M Input Register (PTIM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92 2.3.36 Port M Data Direction Register (DDRM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93 2.3.37 Port M Reduced Drive Register (RDRM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94 2.3.38 Port M Pull Device Enable Register (PERM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94 2.3.39 Port M Polarity Select Register (PPSM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95 2.3.40 Port M Wired-Or Mode Register (WOMM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95 2.3.41 Module Routing Register (MODRR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96 2.3.42 Port P Data Register (PTP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97 2.3.43 Port P Input Register (PTIP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98 2.3.44 Port P Data Direction Register (DDRP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99 2.3.45 Port P Reduced Drive Register (RDRP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 2.3.46 Port P Pull Device Enable Register (PERP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 S12XS-Family Reference Manual, Rev. 1.03 4 PRELIMINARY Freescale Semiconductor 2.3.47 Port P Polarity Select Register (PPSP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101 2.3.48 Port P Interrupt Enable Register (PIEP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101 2.3.49 Port P Interrupt Flag Register (PIFP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102 2.3.50 Port H Data Register (PTH) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102 2.3.51 Port H Input Register (PTIH) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103 2.3.52 Port H Data Direction Register (DDRH) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103 2.3.53 Port H Reduced Drive Register (RDRH) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104 2.3.54 Port H Pull Device Enable Register (PERH) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104 2.3.55 Port H Polarity Select Register (PPSH) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105 2.3.56 Port H Interrupt Enable Register (PIEH) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105 2.3.57 Port H Interrupt Flag Register (PIFH) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106 2.3.58 Port J Data Register (PTJ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106 2.3.59 Port J Input Register (PTIJ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107 2.3.60 Port J Data Direction Register (DDRJ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107 2.3.61 Port J Reduced Drive Register (RDRJ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108 2.3.62 Port J Pull Device Enable Register (PERJ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108 2.3.63 Port J Polarity Select Register (PPSJ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109 2.3.64 Port J Interrupt Enable Register (PIEJ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109 2.3.65 Port J Interrupt Flag Register (PIFJ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110 2.3.66 Port AD0 Data Register 0 (PT0AD0) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110 2.3.67 Port AD0 Data Register 1 (PT1AD0) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111 2.3.68 Port AD0 Data Direction Register 0 (DDR0AD0) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111 2.3.69 Port AD0 Data Direction Register 1 (DDR1AD0) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112 2.3.70 Port AD0 Reduced Drive Register 0 (RDR0AD0) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112 2.3.71 Port AD0 Reduced Drive Register 1 (RDR1AD0) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113 2.3.72 Port AD0 Pull Up Enable Register 0 (PER0AD0) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113 2.3.73 Port AD0 Pull Up Enable Register 1 (PER1AD0) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114 2.3.74 PIM Reserved Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114 2.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114 2.4.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114 2.4.2 Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114 2.4.3 Pins and Ports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117 2.4.4 Pin interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119 2.5 Initialization Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120 2.5.1 Port Data and Data Direction Register writes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120 Chapter 3 Memory Mapping Control (S12XMMCV4) 3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121 3.1.1 Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122 3.1.2 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122 3.1.3 S12X Memory Mapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123 3.1.4 Modes of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123 3.1.5 Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123 3.2 External Signal Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124 S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 5 3.3 Memory Map and Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125 3.3.1 Module Memory Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125 3.3.2 Register Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125 3.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134 3.4.1 MCU Operating Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134 3.4.2 Memory Map Scheme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134 3.4.3 Chip Bus Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141 3.5 Initialization/Application Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142 3.5.1 CALL and RTC Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142 Chapter 4 Interrupt (S12XINTV2) 4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145 4.1.1 Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146 4.1.2 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146 4.1.3 Modes of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147 4.1.4 Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148 4.2 External Signal Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148 4.3 Memory Map and Register Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149 4.3.1 Module Memory Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149 4.3.2 Register Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150 4.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155 4.4.1 S12X Exception Requests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156 4.4.2 Interrupt Prioritization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156 4.4.3 XGATE Requests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157 4.4.4 Priority Decoders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157 4.4.5 Reset Exception Requests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158 4.4.6 Exception Priority . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158 4.5 Initialization/Application Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159 4.5.1 Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159 4.5.2 Interrupt Nesting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159 4.5.3 Wake Up from Stop or Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160 Chapter 5 Background Debug Module (S12XBDMV2) 5.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161 5.1.1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161 5.1.2 Modes of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162 5.1.3 Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163 5.2 External Signal Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163 5.3 Memory Map and Register Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164 5.3.1 Module Memory Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164 5.3.2 Register Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164 5.3.3 Family ID Assignment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169 S12XS-Family Reference Manual, Rev. 1.03 6 PRELIMINARY Freescale Semiconductor 5.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169 5.4.1 Security . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170 5.4.2 Enabling and Activating BDM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170 5.4.3 BDM Hardware Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171 5.4.4 Standard BDM Firmware Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172 5.4.5 BDM Command Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173 5.4.6 BDM Serial Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175 5.4.7 Serial Interface Hardware Handshake Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178 5.4.8 Hardware Handshake Abort Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180 5.4.9 SYNC — Request Timed Reference Pulse . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183 5.4.10 Instruction Tracing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 184 5.4.11 Serial Communication Time Out . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185 Chapter 6 S12X Debug (S12XDBGV3) Module 6.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187 6.1.1 Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187 6.1.2 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188 6.1.3 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188 6.1.4 Modes of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189 6.1.5 Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 190 6.2 External Signal Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 190 6.3 Memory Map and Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 190 6.3.1 Module Memory Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 190 6.3.2 Register Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 191 6.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 207 6.4.1 S12XDBG Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 208 6.4.2 Comparator Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 208 6.4.3 Trigger Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 212 6.4.4 State Sequence Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213 6.4.5 Trace Buffer Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214 6.4.6 Tagging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 220 6.4.7 Breakpoints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 220 Chapter 7 Security (S12XS9SECV2) 7.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223 7.1.1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223 7.1.2 Modes of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 224 7.1.3 Securing the Microcontroller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 224 7.1.4 Operation of the Secured Microcontroller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225 7.1.5 Unsecuring the Microcontroller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 227 7.1.6 Reprogramming the Security Bits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 227 7.1.7 Complete Memory Erase (Special Modes) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 228 S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 7 Chapter 8 S12XE Clocks and Reset Generator (S12XECRGV1) 8.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 229 8.1.1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 229 8.1.2 Modes of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 231 8.1.3 Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 231 8.2 Signal Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 232 8.2.1 VDDPLL, VSSPLL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 232 8.2.2 RESET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 232 8.3 Memory Map and Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 233 8.3.1 Module Memory Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 233 8.3.2 Register Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 234 8.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 249 8.4.1 Functional Blocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 249 8.4.2 Operation Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 254 8.4.3 Low Power Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 255 8.5 Resets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 257 8.5.1 Description of Reset Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 258 8.6 Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260 8.6.1 Description of Interrupt Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 261 Chapter 9 Pierce Oscillator (S12XOSCLCPV2) 9.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 263 9.1.1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 263 9.1.2 Modes of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 263 9.1.3 Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 264 9.2 External Signal Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 264 9.2.1 VDDPLL and VSSPLL — Operating and Ground Voltage Pins . . . . . . . . . . . . . . . . . . . . 264 9.2.2 EXTAL and XTAL — Input and Output Pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 264 9.3 Memory Map and Register Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 266 9.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 266 9.4.1 Gain Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 266 9.4.2 Clock Monitor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 266 9.4.3 Wait Mode Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 266 9.4.4 Stop Mode Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 266 Chapter 10 Analog-to-Digital Converter (ADC12B16CV1) 10.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 267 10.1.1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 267 10.1.2 Modes of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 269 10.1.3 Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 270 10.2 Signal Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 271 S12XS-Family Reference Manual, Rev. 1.03 8 PRELIMINARY Freescale Semiconductor 10.2.1 Detailed Signal Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 271 10.3 Memory Map and Register Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 271 10.3.1 Module Memory Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 271 10.3.2 Register Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 274 10.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 290 10.4.1 Analog Sub-Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 290 10.4.2 Digital Sub-Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 290 10.5 Resets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 291 10.6 Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 292 Chapter 11 Freescale’s Scalable Controller Area Network (S12MSCANV3) 11.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 293 11.1.1 Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 293 11.1.2 Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 294 11.1.3 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 294 11.1.4 Modes of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 295 11.2 External Signal Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 295 11.2.1 RXCAN — CAN Receiver Input Pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 295 11.2.2 TXCAN — CAN Transmitter Output Pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 295 11.2.3 CAN System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 295 11.3 Memory Map and Register Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 296 11.3.1 Module Memory Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 296 11.3.2 Register Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 298 11.3.3 Programmer’s Model of Message Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 320 11.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 329 11.4.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 329 11.4.2 Message Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 330 11.4.3 Identifier Acceptance Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 333 11.4.4 Modes of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 339 11.4.5 Low-Power Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 340 11.4.6 Reset Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 344 11.4.7 Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 345 11.5 Initialization/Application Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 346 11.5.1 MSCAN initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 346 11.5.2 Bus-Off Recovery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 347 Chapter 12 Periodic Interrupt Timer (S12PIT24B4CV1) 12.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 349 12.1.1 Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 349 12.1.2 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 349 12.1.3 Modes of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 349 12.1.4 Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 350 S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 9 12.2 External Signal Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 350 12.3 Register Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 351 12.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 360 12.4.1 Timer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 360 12.4.2 Interrupt Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 361 12.4.3 Hardware Trigger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 362 12.5 Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 362 12.5.1 Startup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 362 12.5.2 Shutdown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 362 12.5.3 Flag Clearing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 362 12.6 Application Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 363 Chapter 13 Pulse-Width Modulator (S12PWM8B8CV1) 13.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 365 13.1.1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 365 13.1.2 Modes of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 366 13.1.3 Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 366 13.2 External Signal Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 366 13.2.1 PWM7 — PWM Channel 7 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 367 13.2.2 PWM6 — PWM Channel 6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 367 13.2.3 PWM5 — PWM Channel 5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 367 13.2.4 PWM4 — PWM Channel 4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 367 13.2.5 PWM3 — PWM Channel 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 367 13.2.6 PWM3 — PWM Channel 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 367 13.2.7 PWM3 — PWM Channel 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 367 13.2.8 PWM3 — PWM Channel 0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 367 13.3 Memory Map and Register Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 367 13.3.1 Module Memory Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 367 13.3.2 Register Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 368 13.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 383 13.4.1 PWM Clock Select . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 383 13.4.2 PWM Channel Timers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 386 13.5 Resets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 394 13.6 Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 395 Chapter 14 Serial Communication Interface (S12SCIV5) 14.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 397 14.1.1 Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 397 14.1.2 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 398 14.1.3 Modes of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 398 14.1.4 Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 399 14.2 External Signal Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 400 S12XS-Family Reference Manual, Rev. 1.03 10 PRELIMINARY Freescale Semiconductor 14.2.1 TXD — Transmit Pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 400 14.2.2 RXD — Receive Pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 400 14.3 Memory Map and Register Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 400 14.3.1 Module Memory Map and Register Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 400 14.3.2 Register Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 401 14.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 413 14.4.1 Infrared Interface Submodule . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 414 14.4.2 LIN Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 414 14.4.3 Data Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 415 14.4.4 Baud Rate Generation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 416 14.4.5 Transmitter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 417 14.4.6 Receiver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 422 14.4.7 Single-Wire Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 430 14.4.8 Loop Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 431 14.5 Initialization/Application Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 431 14.5.1 Reset Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 431 14.5.2 Modes of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 431 14.5.3 Interrupt Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 432 14.5.4 Recovery from Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 434 14.5.5 Recovery from Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 434 Chapter 15 Serial Peripheral Interface (S12SPIV5) 15.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 435 15.1.1 Glossary of Terms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 435 15.1.2 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 435 15.1.3 Modes of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 435 15.1.4 Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 436 15.2 External Signal Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 437 15.2.1 MOSI — Master Out/Slave In Pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 437 15.2.2 MISO — Master In/Slave Out Pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 437 15.2.3 SS — Slave Select Pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 438 15.2.4 SCK — Serial Clock Pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 438 15.3 Memory Map and Register Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 438 15.3.1 Module Memory Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 438 15.3.2 Register Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 439 15.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 447 15.4.1 Master Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 448 15.4.2 Slave Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 449 15.4.3 Transmission Formats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 450 15.4.4 SPI Baud Rate Generation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 455 15.4.5 Special Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 456 15.4.6 Error Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 457 15.4.7 Low Power Mode Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 458 S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 11 Chapter 16 Timer Module (TIM16B8CV2) 16.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 461 16.1.1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 461 16.1.2 Modes of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 462 16.1.3 Block Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 462 16.2 External Signal Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 464 16.2.1 IOC7 — Input Capture and Output Compare Channel 7 Pin . . . . . . . . . . . . . . . . . . . . 464 16.2.2 IOC6 — Input Capture and Output Compare Channel 6 Pin . . . . . . . . . . . . . . . . . . . . 464 16.2.3 IOC5 — Input Capture and Output Compare Channel 5 Pin . . . . . . . . . . . . . . . . . . . . 464 16.2.4 IOC4 — Input Capture and Output Compare Channel 4 Pin . . . . . . . . . . . . . . . . . . . . 464 16.2.5 IOC3 — Input Capture and Output Compare Channel 3 Pin . . . . . . . . . . . . . . . . . . . . 464 16.2.6 IOC2 — Input Capture and Output Compare Channel 2 Pin . . . . . . . . . . . . . . . . . . . . 464 16.2.7 IOC1 — Input Capture and Output Compare Channel 1 Pin . . . . . . . . . . . . . . . . . . . . 465 16.2.8 IOC0 — Input Capture and Output Compare Channel 0 Pin . . . . . . . . . . . . . . . . . . . . 465 16.3 Memory Map and Register Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 465 16.3.1 Module Memory Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 465 16.3.2 Register Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 465 16.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 482 16.4.1 Prescaler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 483 16.4.2 Input Capture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 484 16.4.3 Output Compare . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 484 16.4.4 Pulse Accumulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 485 16.4.5 Event Counter Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 485 16.4.6 Gated Time Accumulation Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 485 16.5 Resets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 486 16.6 Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 486 16.6.1 Channel [7:0] Interrupt (C[7:0]F) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 486 16.6.2 Pulse Accumulator Input Interrupt (PAOVI) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 486 16.6.3 Pulse Accumulator Overflow Interrupt (PAOVF) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 486 16.6.4 Timer Overflow Interrupt (TOF) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 486 Chapter 17 Voltage Regulator (S12VREGL3V3V1) 17.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 489 17.1.1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 489 17.1.2 Modes of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 489 17.1.3 Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 490 17.2 External Signal Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 492 17.2.1 VDDR — Regulator Power Input Pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 492 17.2.2 VDDA, VSSA — Regulator Reference Supply Pins . . . . . . . . . . . . . . . . . . . . . . . . . . . 492 17.2.3 VDD, VSS — Regulator Output1 (Core Logic) Pins . . . . . . . . . . . . . . . . . . . . . . . . . . 492 17.2.4 VDDF — Regulator Output2 (NVM Logic) Pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 493 17.2.5 VDDPLL, VSSPLL — Regulator Output3 (PLL) Pins . . . . . . . . . . . . . . . . . . . . . . . . . 493 S12XS-Family Reference Manual, Rev. 1.03 12 PRELIMINARY Freescale Semiconductor 17.2.6 VDDX — Power Input Pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 493 17.2.7 VREGEN — Optional Regulator Enable Pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 493 17.2.8 VREG_API — Optional Autonomous Periodical Interrupt Output Pin . . . . . . . . . . . . . . 493 17.3 Memory Map and Register Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 493 17.3.1 Module Memory Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 494 17.3.2 Register Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 495 17.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 502 17.4.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 502 17.4.2 Regulator Core (REG) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 502 17.4.3 Low-Voltage Detect (LVD) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 502 17.4.4 Power-On Reset (POR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 502 17.4.5 Low-Voltage Reset (LVR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 502 17.4.6 HTD - High Temperature Detect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 503 17.4.7 Regulator Control (CTRL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 503 17.4.8 Autonomous Periodical Interrupt (API) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 503 17.4.9 Resets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 504 17.4.10Description of Reset Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 504 17.4.11Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 504 Chapter 18 256 KByte Flash Module (S12XFTMR256K1V1) 18.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 508 18.1.1 Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 508 18.1.2 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 509 18.1.3 Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 509 18.2 External Signal Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 510 18.3 Memory Map and Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 510 18.3.1 Module Memory Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 511 18.3.2 Register Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 515 18.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 536 18.4.1 Flash Command Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 536 18.4.2 Flash Command Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 542 18.4.3 Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 560 18.4.4 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 560 18.4.5 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 561 18.5 Security . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 561 18.5.1 Unsecuring the MCU using Backdoor Key Access . . . . . . . . . . . . . . . . . . . . . . . . . . . . 561 18.5.2 Unsecuring the MCU in Special Single Chip Mode using BDM . . . . . . . . . . . . . . . . . 562 18.5.3 Mode and Security Effects on Flash Command Availability . . . . . . . . . . . . . . . . . . . . . 562 18.6 Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 562 Chapter 19 128 KByte Flash Module (S12XFTMR128K1V1) 19.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 566 S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 13 19.1.1 Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 566 19.1.2 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 567 19.1.3 Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 567 19.2 External Signal Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 568 19.3 Memory Map and Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 568 19.3.1 Module Memory Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 569 19.3.2 Register Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 573 19.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 594 19.4.1 Flash Command Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 594 19.4.2 Flash Command Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 600 19.4.3 Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 618 19.4.4 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 618 19.4.5 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 619 19.5 Security . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 619 19.5.1 Unsecuring the MCU using Backdoor Key Access . . . . . . . . . . . . . . . . . . . . . . . . . . . . 619 19.5.2 Unsecuring the MCU in Special Single Chip Mode using BDM . . . . . . . . . . . . . . . . . 620 19.5.3 Mode and Security Effects on Flash Command Availability . . . . . . . . . . . . . . . . . . . . . 620 19.6 Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 620 Chapter 20 64 KByte Flash Module (S12XFTMR64K1V1) 20.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 624 20.1.1 Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 624 20.1.2 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 625 20.1.3 Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 626 20.2 External Signal Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 626 20.3 Memory Map and Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 627 20.3.1 Module Memory Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 627 20.3.2 Register Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 631 20.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 651 20.4.1 Flash Command Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 651 20.4.2 Flash Command Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 657 20.4.3 Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 675 20.4.4 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 675 20.4.5 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 676 20.5 Security . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 676 20.5.1 Unsecuring the MCU using Backdoor Key Access . . . . . . . . . . . . . . . . . . . . . . . . . . . . 676 20.5.2 Unsecuring the MCU in Special Single Chip Mode using BDM . . . . . . . . . . . . . . . . . 677 20.5.3 Mode and Security Effects on Flash Command Availability . . . . . . . . . . . . . . . . . . . . . 677 20.6 Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 677 Appendix A Electrical Characteristics A.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 679 S12XS-Family Reference Manual, Rev. 1.03 14 PRELIMINARY Freescale Semiconductor A.1.1 Parameter Classification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 679 A.1.2 Power Supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 679 A.1.3 Pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 680 A.1.4 Current Injection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 681 A.1.5 Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 681 A.1.6 ESD Protection and Latch-up Immunity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 682 A.1.7 Operating Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 683 A.1.8 Power Dissipation and Thermal Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 684 A.1.9 I/O Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 686 A.1.10 Supply Currents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 690 A.2 ATD Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 694 A.2.1 ATD Operating Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 694 A.2.2 Factors Influencing Accuracy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 694 A.2.3 ATD Accuracy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 696 A.3 NVM, Flash. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 700 A.3.1 Timing Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 700 A.3.2 NVM Reliability Parameters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 704 A.4 Voltage Regulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 706 A.5 Output Loads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 707 A.5.1 Resistive Loads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 707 A.5.2 Capacitive Loads. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 707 A.5.3 Chip Power-up and Voltage Drops . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 707 A.6 Reset, Oscillator and PLL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 709 A.6.1 Startup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 709 A.6.2 Oscillator. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 711 A.6.3 Phase Locked Loop. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 712 A.7 MSCAN. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 714 A.8 SPI Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 715 A.8.1 Master Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 715 A.8.2 Slave Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 717 Appendix B Package Information B.1 112-pin LQFP Mechanical Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 720 B.2 80-Pin QFP Mechanical Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 723 B.3 64-Pin LQFP Mechanical Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 726 Appendix C PCB Layout Guidelines C.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 729 C.1.1 112-Pin LQFP Recommended PCB Layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 730 C.1.2 80-Pin QFP Recommended PCB Layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 731 C.1.3 64-Pin LQFP Recommended PCB Layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 732 S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 15 Appendix D Derivative Differences D.1 Memory Sizes and Package Options S12XS-Family . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 733 Appendix E Detailed Register Address Map E.1 Detailed Register Map. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 734 Appendix F Ordering Information F.1 Ordering Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 756 S12XS-Family Reference Manual, Rev. 1.03 16 PRELIMINARY Freescale Semiconductor Chapter 1 Device Overview S12XS-Family 1.1 Introduction The new S12XS-family of 16-bit micro controllers is a compatible, reduced version of the S12XE-family. These families provide an easy approach to develop common platforms from low-end to high-end applications, minimizing the redesign of software and hardware. Targeted at generic automotive applications and CAN nodes, some typical examples of these applications are: Body Controllers, Occupant Detection, Door Modules, RKE Receivers, Smart Actuators, Lighting Modules and Smart Junction Boxes amongst many others. The S12XS-family retains many of the features of the S12XE-family including Error Correction Code (ECC) on Flash memory, a separate Data-Flash Module for code or data storage, a Frequency Modulated Locked Loop (IPLL) that improves the EMC performance and a fast ATD converter. S12XS-family will deliver 32-bit performance with all the advantages and efficiencies of a 16-bit MCU. It will retain the low cost, power consumption, EMC and code-size efficiency advantages currently enjoyed by users of Freescale’s existing 16-bit S12 and S12X MCU families. Like members of other S12X families, the S12XS-family will run 16-bit wide accesses without wait states for all peripherals and memories. The S12XS-family will be available in 112-pin LQFP, 80-pin QFP, 64-pin LQFP package options and maintains a high level of pin compatibility with the S12XE-family. In addition to the I/O ports available in each module, up to 18 further I/O ports are available with interrupt capability allowing Wake-Up from STOP or WAIT modes. The peripheral set includes MSCAN, SPI, two SCIs, an 8-channel 24-bit periodic interrupt timer, 8channel 16-bit Timer, 8-channel PWM and up to 16- channel 12-bit ATD converter. Software controlled peripheral-to-port routing enables access to a flexible mix of the peripheral modules in the lower pin count package options. 1.1.1 Features Features of the S12XS-Family are listed here. Please see Table D-1for memory options and Table D-2 for the peripheral features that are available on the different family members. • 16-bit CPU12X — Upward compatible with S12 instruction set with the exception of five Fuzzy instructions (MEM, WAV, WAVR, REV, REVW) which have been removed — Enhanced indexed addressing S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 17 Device Overview S12XS-Family — Access to large data segments independent of PPAGE • INT (interrupt module) — Seven levels of nested interrupts — Flexible assignment of interrupt sources to each interrupt level. — External non-maskable high priority interrupt (XIRQ) — The following inputs can act as Wake-up Interrupts – IRQ and non-maskable XIRQ – CAN receive pins – SCI receive pins – Depending on the package option up to 20 pins on ports J, H and P configurable as rising or falling edge sensitive • MMC (module mapping control) • DBG (debug module) — Monitoring of CPU bus with tag-type or force-type breakpoint requests — 64 x 64-bit circular trace buffer captures change-of-flow or memory access information • BDM (background debug mode) • OSC_LCP (oscillator) — Low power loop control Pierce oscillator utilizing a 4MHz to 16MHz crystal — Good noise immunity — Full-swing Pierce option utilizing a 2MHz to 40MHz crystal — Transconductance sized for optimum start-up margin for typical crystals • IPLL (Internally filtered, frequency modulated phase-locked-loop clock generation) — No external components required — Configurable option to spread spectrum for reduced EMC radiation (frequency modulation) • CRG (clock and reset generation) — COP watchdog — Real time interrupt — Clock monitor — Fast wake up from STOP in self clock mode • Memory Options — 64K, 128K and 256K byte Flash or ROM — Flash General Features – 64 data bits plus 8 syndrome ECC (Error Correction Code) bits allow single bit failure correction and double fault detection – Erase sector size 1024 bytes – Automated program and erase algorithm – Protection scheme to prevent accidental program or erase – Security option to prevent unauthorized access – Sense-amp margin level setting for reads S12XS-Family Reference Manual, Rev. 1.03 18 PRELIMINARY Freescale Semiconductor Device Overview S12XS-Family — 4K and 8K byte Data Flash space (Not available on ROM versions) – 16 data bits plus 6 syndrome ECC (Error Correction Code) bits allow single bit failure correction and double fault detection – Erase sector size 256 bytes – Automated program and erase algorithm — 4K, 8K and 12K byte RAM • 16-channel, 12-bit Analog-to-Digital converter — 8/10/12 Bit resolution — 3µs, 10-bit single conversion time — Left or right justified result data — External and internal conversion trigger capability — Internal oscillator for conversion in Stop modes — Wake from low power modes on analog comparison > or <= match — Continuous conversion mode — Multiplexer for 16 analog input channels — Multiple channel scans — Pins can also be used as digital I/O • MSCAN (1 M bit per second, CAN 2.0 A, B software compatible module) — 1 Mbit per second, CAN 2.0 A, B software compatible module – Standard and extended data frames – 0 - 8 bytes data length – Programmable bit rate up to 1 Mbps — Five receive buffers with FIFO storage scheme — Three transmit buffers with internal prioritization — Flexible identifier acceptance filter programmable as: – 2 x 32-bit – 4 x 16-bit – 8 x 8-bit — Wake-up with integrated low pass filter option — Loop back for self test — Listen-only mode to monitor CAN bus — Bus-off recovery by software intervention or automatically — 16-bit time stamp of transmitted/received messages • TIM (standard timer module) — 8 x 16-bit channels for input capture or output compare — 16-bit free-running counter with 8-bit precision prescaler — 1 x 16-bit pulse accumulator • PIT (periodic interrupt timer) — Up to four timers with independent time-out periods S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 19 Device Overview S12XS-Family — Time-out periods selectable between 1 and 224 bus clock cycles — Time-out interrupt and peripheral triggers — Start of timers can be aligned • Up to 8 channel x 8-bit or 4 channel x 16-bit Pulse Width Modulator — Programmable period and duty cycle per channel — Center- or left-aligned outputs — Programmable clock select logic with a wide range of frequencies • Serial Peripheral Interface Module (SPI) — Configurable for 8 or 16-bit data size — Full-duplex or single-wire bidirectional — Double-buffered transmit and receive — Master or Slave mode — MSB-first or LSB-first shifting — Serial clock phase and polarity options • Two Serial Communication Interfaces (SCI) — Full-duplex or single wire operation — Standard mark/space non-return-to-zero (NRZ) format — Selectable IrDA 1.4 return-to-zero-inverted (RZI) format with programmable pulse widths — 13-bit baud rate selection — Programmable character length — Programmable polarity for transmitter and receiver — Receive wakeup on active edge — Break detect and transmit collision detect supporting LIN • On-Chip Voltage Regulator — Two parallel, linear voltage regulators with bandgap reference — Low-voltage detect (LVD) with low-voltage interrupt (LVI) — Power-on reset (POR) circuit — Low-voltage reset (LVR) • Low-power wake-up timer (API) — Internal oscillator driving a down counter — Trimmable to +/-10% accuracy — Time-out periods range from 0.2ms to ~13s with a 0.2ms resolution • Input/Output — Up to 91 general-purpose input/output (I/O) pins depending on the package option and 2 input- only pins — Hysteresis and configurable pull up/pull down device on all input pins — Configurable drive strength on all output pins • Package Options — 112-pin low-profile quad flat-pack (LQFP) S12XS-Family Reference Manual, Rev. 1.03 20 PRELIMINARY Freescale Semiconductor Device Overview S12XS-Family — 80-pin quad flat-pack (QFP) — 64-pin low-profile quad flat-pack (LQFP) • Operating Conditions — Wide single Supply Voltage range 3.135V to 5.5V at full performance – Separate supply for internal voltage regulator and I/O allow optimized EMC filtering — 40MHz maximum CPU bus frequency — Ambient temperature range –40°C to 125°C — Temperature Options: – –40°C to 85°C – –40°C to 105°C – –40°C to 125°C 1.1.2 Modes of Operation Operating modes: • Normal single-chip mode • Special single-chip mode with active background debug mode NOTE This chip family does not support external bus modes. Low-power modes: • System stop modes — Pseudo stop mode — Full stop mode with fast wake-up option • System wait mode S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 21 Device Overview S12XS-Family 1.1.3 Block Diagram Figure 1-1 shows a block diagram of the S12XS-Family devices VDDR VDD VDDF VDDPLL BKGD EXTAL XTAL RESET TEST PE0 PE1 PE2 PE3 PE4 PE5 PE6 PE7 PA[7:0] PB[7:0] PTA PTE 64K … 256K bytes Flash or ROM 4K … 12K bytes RAM ATD 8/10/12-bit 16-channel Analog-Digital Converter 4K … 8K bytes Data Flash AN[15:0] Voltage Regulator CPU12X Debug Module Single-wire Background 4 address breakpoints Debug Module 2 data breakpoints 512 Byte Trace Buffer Amplitude Controlled Low Power Pierce or Full drive Pierce Oscillator PLL with Frequency Modulation option Clock Monitor COP Watchdog Periodic Interrupt Async. Periodic Int. PIT 4ch 24-bit Timer Reset Generation and Test Entry Multilevel Interrupt Module XIRQ IRQ TIM 16-bit 8 channel Timer IOC0 IOC1 IOC2 IOC3 IOC4 IOC5 IOC6 IOC7 PWM 8-bit 8 channel Pulse Width Modulator PWM0 PWM1 PWM2 PWM3 PWM4 PWM5 PWM6 PWM7 CAN0 msCAN 2.0B RXCAN TXCAN ECLK XCLKS/ECLKX2 SCI0 Asynchronous Serial IF SCI1 Asynchronous Serial IF SPI0 Synchronous Serial IF RXD TXD RXD TXD MISO MOSI SCK SS PTB PK[7,5:0] PTK Figure 1-1. S12XS-Family Block Diagram PTJ (Wake-up Int) PTH (Wake-up Int) PTS PTM PTP (Wake-Up Int) PTT PTAD VDDA VSSA VRH VRL PAD[15:0] PT0 PT1 PT2 PT3 PT4 PT5 PT6 PT7 PP0 PP1 PP2 PP3 PP4 PP5 PP6 PP7 PM0 PM1 PM2 PM3 PM4 PM5 PM6 PM7 PS0 PS1 PS2 PS3 PS4 PS5 PS6 PS7 PH0 PH1 PH2 PH3 PH4 PH5 PH6 PH7 PJ0 PJ1 PJ6 PJ7 S12XS-Family Reference Manual, Rev. 1.03 22 PRELIMINARY Freescale Semiconductor Device Overview S12XS-Family 1.1.4 Device Memory Map Table 1-1 shows the device register memory map. Table 1-1. Device Register Memory Map Address 0x0000–0x0009 0x000A–0x000B 0x000C–0x000D 0x000E–0x000F 0x0010–0x0017 0x0018–0x0019 0x001A–0x001B 0x001C–0x001F 0x0020–0x002F 0x0030–0x0031 0x0032–0x0033 0x0034–0x003F 0x0040–0x006F 0x0070–0x00C7 0x00C8–0x00CF 0x00D0–0x00D7 0x00D8–0x00DF 0x00E0–0x00FF 0x0100–0x0113 0x0114–0x011F 0x0120–0x012F 0x0130–0x013F 0x0140–0x017F 0x0180–0x023F 0x0240–0x027F 0x0280–0x02BF 0x02C0–0x02EF 0x02F0–0x02F7 0x02F8–0x02FF 0x0300–0x0327 0x0328–0x033F 0x0340–0x0367 Module Size (Bytes) PIM (port integration module) 10 MMC (memory map control) 2 PIM (port integration module) 2 Reserved 2 MMC (memory map control) 8 Reserved 2 Device ID register 2 PIM (port integration module) 4 DBG (debug module) 16 Reserved 2 PIM (port integration module) 2 ECRG (clock and reset generator) 12 TIM (timer module) 48 Reserved 88 SCI0 (serial communications interface) 8 SCI1 (serial communications interface) 8 SPI0 (serial peripheral interface) 8 Reserved 32 FTMR control registers 20 Reserved 12 INT (interrupt module) 16 Reserved 16 CAN0 64 Reserved 192 PIM (port integration module) 64 Reserved 64 ATD0 (analog-to-digital converter 12 bit 16-channel) 48 Voltage regulator 8 Reserved 8 PWM (pulse-width modulator 8 channels) 40 Reserved 24 PIT (periodic interrupt timer) 40 S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 23 Device Overview S12XS-Family Table 1-1. Device Register Memory Map (continued) Address 0x0368–0x07FF Reserved Module Size (Bytes) 1176 NOTE Reserved register space shown in Table 1-1 is not allocated to any module. This register space is reserved for future use. Writing to these locations have no effect. Read access to these locations returns zero. 1.1.5 Address Mapping Figure 1-2 shows S12XS CPU and BDM local address translation to the global memory map. It indicates also the location of the internal resources in the memory map. S12XS-Family Reference Manual, Rev. 1.03 24 PRELIMINARY Freescale Semiconductor CPU and BDM Local Memory Map 0x0000 0x0800 0x0C00 0x1000 0x2000 2K REGISTERS 1K DFLASH window Reserved 4K RAM window 8K RAM 0x4000 Unpaged 16K FLASH 0x8000 16K FLASH window EPAGE RPAGE PPAGE 0xC000 0xFFFF Unpaged 16K FLASH Vectors Device Overview S12XS-Family RAMSIZE Global Memory Map 0x00_0000 0x00_07FF 2K REGISTERS Unimplemented RAM RAM_LOW 0x0F_FFFF DF_HIGH 0x13_FFFF RAM DFLASH DFLASH Resources Unimplemented Space 0x3F_FFFF Unimplemented FLASH FLASH_LOW FLASH FLASHSIZE 0x7F_FFFF Figure 1-2. S12XS-Family Global Memory Map S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 25 Device Overview S12XS-Family Accessing the reserved area in the range of 0x0C00 to 0x0FFF will return undefined data values. A CPU access to any unimplemented space causes an illegal address reset. The range between 0x10_0000 and 0x13_FFFF is mapped to DFLASH (Data Flash). The DFLASH block sizes are listed in Table 1-2. Table 1-2. Derivative Dependent Memory Parameters of Device Internal Resources Device FLASH_LOW SIZE/ PPAGE1 RAM_LOW S12XS256 0x7C_0000 256K / 16 0x0F_D000 S12XS128 0x7E_0000 128K / 8 0x0F_E000 S12XS64 0x7F_0000 64K / 4 0x0F_F000 1 Number of 16K pages addressable via PPAGE register 2 Number of 4K pages addressing the RAM. 3 Number of 1K pages addressing the DFLASH SIZE/ RPAGE2 12K / 3 8K / 2 4K / 1 DF_HIGH 0x10_1FFF 0x10_1FFF 0x10_0FFF SIZE/ EPAGE3 8K / 8 8K / 8 4K / 4 1.1.6 Detailed Register Map The detailed register map is listed in the appendix of the reference manual. 1.1.7 Part ID Assignments The part ID is located in two 8-bit registers PARTIDH and PARTIDL (addresses 0x001A and 0x001B). The read-only value is a unique part ID for each revision of the chip. Table 1-3 shows the assigned part ID number and Mask Set number. The Version ID is a word located in a flash information row at 0x40_00E8. The version ID number indicates a specific version of internal NVM variables used to patch NVM errata. The default is no patch (0xFFFF). Device MC9S12XS256 MC9S12XS128 MC9S12XS64 Table 1-3. Assigned Part ID Numbers Mask Set Number 0M05M 0M04M 1M04M 0M04M 1M04M TBD Part ID1 $C0C0 $C1C0 $C1C1 $C1C0 $C1C1 $C2C0 Version ID 0xFFFF 0xFFFF 0xFFFF 0xFFFF 0xFFFF 0xFFFF S12XS-Family Reference Manual, Rev. 1.03 26 PRELIMINARY Freescale Semiconductor 1 The coding is as follows: Bit 15-12: Major family identifier Bit 11-6: Minor family identifier Bit 5-4: Major mask set revision number including FAB transfers Bit 3-0: Minor — non full — mask set revision Device Overview S12XS-Family 1.2 Signal Description This section describes signals that connect off-chip. It includes a pinout diagram, a table of signal properties, and detailed discussion of signals. It is built from the signal description sections of the individual IP blocks on the device. 1.2.1 Device Pinout The XS-family of devices offers pin-compatible packaged devices to assist with system development and accommodate expansion of the application. The S12XS-family devices are offered in the following package options: • 112-pin LQFP • 80-pin QFP • 64-pin LQFP S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 27 Device Overview S12XS-Family 112 PP4/KWP4/PWM4 111 PP5/KPW5/PWM5 110 PP6/KWP6/PWM6 109 PP7/KWP7/PWM7 108 PK7 107 VDDX1 106 VSSX1 105 PM0/RXCAN0/RXD1 104 PM1/TXCAN0/TXD1 103 PM2/MISO0 102 PM3/SS0 101 PM4/MOSI0 100 PM5/SCK0 99 PJ6/KWJ6 98 PJ7/KWJ7 97 TEST 96 PS7/SS0 95 PS6/SCK0 94 PS5/MOSI0 93 PS4/MISO0 92 PS3/TXD1 91 PS2/RXD1 90 PS1/TXD0 89 PS0/RXD0 88 PM6 87 PM7 86 VSSA 85 VRL PWM3/KWP3/PP3 1 TXD1/IOC2/PWM2/KWP2/PP2 2 IOC1/PWM1/KWP1/PP1 3 RXD1/IOC0/PWM0/KWP0/PP0 4 PK3 5 PK2 6 PK1 7 PK0 8 IOC0/PT0 9 IOC1/PT1 10 IOC2/PT2 11 IOC3/PT3 12 VDDF 13 VSS1 14 PWM4/IOC4/PT4 15 VREG_API/PWM5/IOC5/PT5 16 PWM6/IOC6/PT6 17 PWM7/IOC7/PT7 18 PK5 19 PK4 20 KWJ1/PJ1 21 KWJ0/PJ0 22 MODC/BKGD 23 PB0 24 PB1 25 PB2 26 PB3 27 PB4 28 S12XS-Family 112LQFP Pins shown in BOLD are not available on the 80 QFP package 112LQFP引脚图 84 VRH 83 VDDA 82 PAD15/AN15 81 PAD07/AN07 80 PAD14/AN14 79 PAD06/AN06 78 vsD13/AN13? 77 PAD05/AN05 76 PAD12/AN12 75 PAD04/AN04 74 PAD11/AN11 73 PAD03/AN03 72 PAD10/AN10 71 PAD02/AN02 70 PAD09/AN09 69 PAD01/AN01 68 PAD08/AN08 67 PAD00/AN00 66 VSS2 65 VDD 64 PA7 63 PA6 62 PA5 61 PA4 60 PA3 59 PA2 58 PA1 57 PA0 PB5 29 PB6 30 PB7 31 KWH7/PH7 32 KWH6/PH6 33 KWH5/PH5 34 KWH4/PH4 35 XCLKS/ECLKX2/PE7 36 PE6 37 PE5 38 ECLK/PE4 39 VSSX2 40 VDDX2 41 RESET 42 VDDR 43 VSS3 44 VSSPLL 45 EXTAL 46 XTAL 47 VDDPLL 48 KWH3/PH3 49 KWH2/PH2 50 KWH1/PH1 51 KWH0/PH0 52 PE3 53 PE2 54 IRQ/PE1 55 XIRQ/PE0 56 Figure 1-3. S12XS-Family Pin Assignments 112-pin LQFP Package S12XS-Family Reference Manual, Rev. 1.03 28 PRELIMINARY Freescale Semiconductor Device Overview S12XS-Family 80QFP引脚图 80 PP4/KWP4/PWM4 79 PP5/KPW5/PWM5 78 PP7/KPW7/PWM7 77 VDDX1 76 VSSX1 75 PM0/RXCAN0/RXD1 74 PM1/TXCAN0/TXD1 73 PM2/MISO0 72 PM3/SS0 71 PM4/MOSI0 70 PM5/SCK0 69 PJ6/KWJ6 68 PJ7/KWJ7 67 TEST 66 PS3/TXD1 65 PS2/RXD1 64 PS1/TXD0 63 PS0/RXD0 62 VSSA 61 VRL PWM3/KWP3/PP3 1 TXD1/IOC2/PWM2/KWP2/PP2 2 IOC1/PWM1/KWP1/PP1 3 RXD1/IOC0/PWM0/KWP0/PP0 4 IOC0/PT0 5 IOC1/PT1 6 IOC2/PT2 7 IOC3/PT3 8 VDDF 9 VSS1 10 PWM4/IOC4/PT4 11 VREG_API/PWM5/IOC5/PT5 12 PWM6/IOC6/PT6 13 PWM7/IOC7/PT7 14 MODC/BKGD 15 PB0 16 PB1 17 PB2 18 PB3 19 PB4 20 S12XS-Family 80QFP Pins shown in BOLD are not available on the 64 QFP package 60 VRH 59 VDDA 58 PAD07/AN07 57 PAD06/AN06 56 PAD05/AN05 55 PAD04/AN04 54 PAD03/AN03 53 PAD02/AN02 52 PAD01/AN01 51 PAD00/AN00 50 VSS2 49 VDD 48 PA7 47 PA6 46 PA5 45 PA4 44 PA3 43 PA2 42 PA1 41 PA0 PB5 21 PB6 22 PB7 23 XCLKS/ECLKX2/PE7 24 PE6 25 PE5 26 ECLK/PE5 27 VSSX2 28 VDDX2 29 RESET 30 VDDR 31 VSS3 32 VSSPLL 33 EXTAL 34 XTAL 35 VDDPLL 36 PE3 37 PE2 38 IRQ/PE1 39 XIRQ/PE0 40 Figure 1-4. S12XS-Family Pin Assignments 80-pin QFP Package S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 29 Device Overview S12XS-Family 64 PP5/KPW5/PWM5 63 PP7/KWP7/PWM7 62 VDDX1 61 VSSX1 60 PM0/RXCAN0/RXD1 59 PM1/TXCAN0/TXD1 58 PM2/MISO0 57 PM3/SS0 56 PM4/MOSI0 55 PM5/SCK0 54 TEST 53 PS3/TXD1 52 PS2/RXD1 51 PS1/TXD0 50 PS0/RXD0 49 VSSA/VRL 64LQFP引脚图 PWM3/KWP3/PP3 1 TXD1/IOC2/PWM2/KWP2/PP2 2 IOC1/PWM1/KWP1/PP1 3 RXD1/IOC0/PWM0/KWP0/PP0 4 IOC0/PT0 5 IOC1/PT1 6 IOC2/PT2 7 IOC3/PT3 8 VDDF 9 VSS1 10 PWM4/IOC4/PT4 11 VREG_API/PWM5/IOC5/PT5 12 PWM6/IOC6/PT6 13 PWM7/IOC7/PT7 14 MODC/BKGD 15 PB0 16 S12XS-Family 64LQFP 48 VRH 47 VDDA 46 PAD07/AN07 45 PAD06/AN06 44 PAD05/AN05 43 PAD04/AN04 42 PAD03/AN03 41 PAD02/AN02 40 PAD01/AN01 39 PAD00/AN00 38 VSS2 37 VDD 36 PA3 35 PA2 34 PA1 33 PA0 PB5 17 PB6 18 PB7 19 XCLKS/ECLKX2/PE7 20 ECLK/PE4 21 VSSX2 22 VDDX2 23 RESET 24 VDDR 25 VSS3 26 VSSPLL 27 EXTAL 28 XTAL 29 VDDPLL 30 IRQ/PE1 31 XIRQ/PE0 32 Figure 1-5. S12XS-Family Pin Assignments 64-pin LQFP Package S12XS-Family Reference Manual, Rev. 1.03 30 PRELIMINARY Freescale Semiconductor 1.2.2 引脚分配概览表 Pin Assignment Overview Device Overview S12XS-Family Table 1-4 provides a summary of which Ports are available for each package option. Routing of pin functions is summarized in Table 1-5. Table 1-4. Port Availability by Package Option Port Port AD/ADC Channels Port A pins Port B pins Port E pins inc. IRQ/XIRQ input only Port H Port J Port K Port M Port P Port S Port T Sum of Ports I/O Power Pairs VDDX/VSSX 112 LQFP 16/16 8 8 8 8 4 7 8 8 8 8 91 2/2 80 QFP 8/8 8 8 8 0 2 0 6 7 4 8 59 2/2 64 LQFP 8/8 4 4 4 0 0 0 6 6 4 8 44 2/2 Table 1-5. Peripheral - Port Routing Options1 SCI1 SPI0 PWM TIM PM[1:0] O PM[5:2] O PP[2,0] O PP[2:0] O PP[7:4] X PS[3:2] X PS[7:4] X PT[2:0] X PT[7:4] O 1 “X” denotes reset condition, “O” denotes a possible rerouting under software control S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 31 Device Overview S12XS-Family 32 Table 1-6 provides a pin out summary listing the availability and functionality of individual pins for each package option. 引脚分配摘要 Table 1-6. Pin-Out Summary1 S12XS-Family Reference Manual, Rev. 1.03 PRELIMINARY Package Terminal LQFP 112 1 QFP 80 1 LQFP 64 1 2 2 2 3 3 3 4 4 4 5 - - 6 - - 7 - - 8 - - 9 5 5 10 6 6 11 7 7 12 8 8 13 9 9 14 10 10 15 11 11 Pin PP3 PP2 PP1 PP0 PK3 PK2 PK1 PK0 PT0 PT1 PT2 PT3 VDDF VSS1 PT4 Function 2nd Func. KWP3 3rd Func. PWM3 4th Func. — KWP2 PWM2 IOC2 KWP1 PWM1 IOC1 KWP0 PWM0 IOC0 — — — — — — — — — — — — IOC0 — — IOC1 — — IOC2 — — IOC3 — — — — — — — — IOC4 PWM4 — 5th Func. — TXD1 — RXD1 — — — — — — — — — — — Power Supply Internal Pull Resistor CTRL Reset State Description VDDX VDDX VDDX VDDX VDDX VDDX VDDX VDDX VDDX VDDX VDDX VDDX — — VDDX PERP/PPSP Disabled Port P I/O, interrupt, PWM channel PERP/PPSP Disabled Port P I/O, interrupt, PWM/TIM channel, TXD of SCI1 PERP/PPSP Disabled Port P I/O, interrupt, PWM/TIM channel PERP/PPSP Disabled Port P I/O, interrupt, PWM/TIM channel, RXD of SCI1 PUCR Up Port K I/O PUCR Up Port K I/O PUCR Up Port K I/O PUCR Up Port K I/O PERT/PPST Disabled Port T I/O, TIM channel PERT/PPST Disabled Port T I/O, TIM channel PERT/PPST Disabled Port T I/O, TIM channel PERT/PPST Disabled Port T I/O, TIM channel — — — — — — PERT/PPST Disabled Port T I/O, PWM/TIM channel Freescale Semiconductor 33 PRELIMINARY Freescale Semiconductor S12XS-Family Reference Manual, Rev. 1.03 Package Terminal LQFP 112 16 QFP 80 12 LQFP 64 12 17 13 13 18 14 14 19 - - 20 - - 21 - - 22 - - 23 15 15 24 16 16 25 17 - 26 18 - 27 19 - 28 20 - 29 21 17 30 22 18 31 23 19 32 - - 33 - - 34 - - 35 - - Pin PT5 PT6 PT7 PK5 PK4 PJ1 PJ0 BKGD PB0 PB1 PB2 PB3 PB4 PB5 PB6 PB7 PH7 PH6 PH5 PH4 Table 1-6. Pin-Out Summary1 Function 2nd Func. IOC5 IOC6 3rd Func. PWM5 PWM6 4th Func. VREG_ API — IOC7 PWM7 — — — — — — — KWJ1 — — KWJ0 — — MODC — — — — — — — — — — — — — — — — — — — — — — — — — — KWH7 — — KWH6 — — KWH5 — — KWH4 — — 5th Func. — — — — — — — — — — — — — — — — — — — — Power Supply Internal Pull Resistor CTRL Reset State Description VDDX VDDX VDDX VDDX VDDX VDDX VDDX VDDX VDDX VDDX VDDX VDDX VDDX VDDX VDDX VDDX VDDX VDDX VDDX VDDX PERT/PPST Disabled Port T I/O, PWM/TIM channel, API output PERT/PPST Disabled Port T I/O, channel of PWM/TIM PERT/PPST Disabled Port T I/O, channel of PWM/TIM PUCR Up Port K I/O PUCR Up Port K I/O PERJ/PPSJ Up Port J I/O, interrupt PERJ/PPSJ Up Port J I/O, interrupt Always on Up Background debug PUCR Disabled Port B I/O PUCR Disabled Port B I/O PUCR Disabled Port B I/O PUCR Disabled Port B I/O PUCR Disabled Port B I/O PUCR Disabled Port B I/O PUCR Disabled Port B I/O PUCR Disabled Port B I/O PERH/PPSH Disabled Port H I/O, interrupt PERH/PPSH Disabled Port H I/O, interrupt PERH/PPSH Disabled Port H I/O, interrupt PERH/PPSH Disabled Port H I/O, interrupt Device Overview S12XS-Family Freescale Semiconductor PRELIMINARY 34 S12XS-Family Reference Manual, Rev. 1.03 Package Terminal LQFP 112 36 QFP 80 24 LQFP 64 20 37 25 - 38 26 - 39 27 21 40 28 22 41 29 23 42 30 24 43 31 25 44 32 26 45 33 27 46 34 28 47 35 29 48 36 30 49 - - 50 - - 51 - - 52 - - 53 37 - 54 38 - Table 1-6. Pin-Out Summary1 Function Pin 2nd Func. 3rd Func. 4th Func. PE7 XCLKS ECLKX2 — PE6 — — — PE5 — — — PE4 ECLK — — VSSX2 — — — VDDX2 — — — RESET — — — VDDR — — — VSS3 — — — VSSPLL — — — EXTAL — — — XTAL — — — VDDPLL — — — PH3 KWH3 — — PH2 KWH2 — — PH1 KWH1 — — PH0 KWH0 — — PE3 — — — PE2 — — — 5th Func. — — — — — — — — — — — — — — — — — — — Power Supply Internal Pull Resistor CTRL Reset State Description VDDX PUCR Up Port E I/O, system clock output, clock select input VDDX While RESET pin is low: down2 Port E I/O VDDX While RESET pin is low: down2 Port E I/O VDDX PUCR Up Port E I/O, bus clock output — — — — — — — — VDDX — PULLUP — — External reset — — — — — — — — — VDDPLL NA VDDPLL NA — — NA Oscillator pin NA Oscillator pin — — VDDX VDDX VDDX VDDX VDDX VDDX PERH/PPSH Disabled Port H I/O, interrupt PERH/PPSH Disabled Port H I/O, interrupt PERH/PPSH Disabled Port H I/O, interrupt PERH/PPSH Disabled Port H I/O, interrupt PUCR Up Port E I/O PUCR Up Port E I/O Device Overview S12XS-Family 35 PRELIMINARY Freescale Semiconductor S12XS-Family Reference Manual, Rev. 1.03 Package Terminal LQFP 112 55 QFP 80 39 LQFP 64 31 56 40 32 57 41 33 58 42 34 59 43 35 60 44 36 61 45 - 62 46 - 63 47 - 64 48 - 65 49 37 66 50 38 67 51 39 68 - - 69 52 40 70 - - 71 53 41 Pin PE1 PE0 PA0 PA1 PA2 PA3 PA4 PA5 PA6 PA7 VDD VSS2 PAD00 PAD08 PAD01 PAD09 PAD02 Table 1-6. Pin-Out Summary1 Function 2nd Func. IRQ 3rd Func. — 4th Func. — 5th Func. — Power Supply VDDX XIRQ — — — VDDX — — — — VDDX — — — — VDDX — — — — VDDX — — — — VDDX — — — — VDDX — — — — VDDX — — — — VDDX — — — — VDDX — — — — — — — — — — AN00 — — — VDDA AN08 — — — VDDA AN01 — — — VDDA AN09 — — — VDDA AN02 — — — VDDA Internal Pull Resistor CTRL Reset State Description PUCR Up Port E Input, maskable interrupt PUCR Up Port E Input, non- maskable interrupt PUCR Disabled Port A I/O PUCR Disabled Port A I/O PUCR Disabled Port A I/O PUCR Disabled Port A I/O PUCR Disabled Port A I/O PUCR Disabled Port A I/O PUCR Disabled Port A I/O PUCR Disabled Port A I/O — — — — — — PER1AD Disabled Port AD I/O, analog input of ATD PER0AD Disabled Port AD I/O, analog input of ATD PER1AD Disabled Port AD I/O, analog input of ATD PER0AD Disabled Port AD I/O, analog input of ATD PER1AD Disabled Port AD I/O, analog input of ATD Device Overview S12XS-Family Freescale Semiconductor PRELIMINARY 36 S12XS-Family Reference Manual, Rev. 1.03 Package Terminal LQFP 112 72 QFP 80 - LQFP 64 - 73 54 42 74 - - 75 55 43 76 - - 77 56 44 78 - - 79 57 45 80 - - 81 58 46 82 - - 83 59 47 84 60 48 85 61 49 86 62 49 Pin PAD10 PAD03 PAD11 PAD04 PAD12 PAD05 PAD13 PAD06 PAD14 PAD07 PAD15 VDDA VRH VRL3 VSSA Table 1-6. Pin-Out Summary1 Function 2nd Func. AN10 3rd Func. — 4th Func. — 5th Func. — Power Supply VDDA AN03 — — — VDDA AN11 — — — VDDA AN04 — — — VDDA AN12 — — — VDDA AN05 — — — VDDA AN13 — — — VDDA AN06 — — — VDDA AN14 — — — VDDA AN07 — — — VDDA AN15 — — — VDDA — — — — — — — — — — — — — — — — — — — — Internal Pull Resistor CTRL Reset State Description PER0AD Disabled Port AD I/O, analog input of ATD PER1AD Disabled Port AD I/O, analog input of ATD PER0AD Disabled Port AD I/O, analog input of ATD PER1AD Disabled Port AD I/O, analog input of ATD PER0AD Disabled Port AD I/O, analog input of ATD PER1AD Disabled Port AD I/O, analog input of ATD PER0AD Disabled Port AD I/O, analog input of ATD PER1AD Disabled Port AD I/O, analog input of ATD PER0AD Disabled Port AD I/O, analog input of ATD PER1AD Disabled Port AD I/O, analog input of ATD PER0AD Disabled Port AD I/O, analog input of ATD — — — — — — — — — — — — Device Overview S12XS-Family 37 PRELIMINARY Freescale Semiconductor S12XS-Family Reference Manual, Rev. 1.03 Package Terminal LQFP 112 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 QFP 80 63 64 65 66 67 68 69 70 71 LQFP 64 50 51 52 53 54 55 56 102 72 57 103 73 58 104 74 59 105 75 60 Pin PM7 PM6 PS0 PS1 PS2 PS3 PS4 PS5 PS6 PS7 TEST PJ7 PJ6 PM5 PM4 PM3 PM2 PM1 PM0 Table 1-6. Pin-Out Summary1 Function 2nd Func. — — RXD0 TXD0 RXD1 TXD1 MISO0 MOSI0 SCK0 SS0 — KWJ7 KWJ6 SCK0 MOSI0 3rd Func. — — — — — — — — — — — — — — — 4th Func. — — — — — — — — — — — — — — — SS0 — — MISO0 — — TXCAN0 TXD1 — RXCAN0 RXD1 — 5th Func. — — — — — — — — — — — — — — — — — — — Power Supply Internal Pull Resistor CTRL Reset State Description VDDX VDDX VDDX VDDX VDDX VDDX VDDX VDDX VDDX VDDX N.A. VDDX VDDX VDDX VDDX VDDX VDDX VDDX VDDX PERM/PPSM Disabled Port M I/O PERM/PPSM Disabled Port M I/O PERS/PPSS Up Port S I/O, RXD of SCI0 PERS/PPSS Up Port S I/O, TXD of SCI0 PERS/PPSS Up Port S I/O, RXD of SCI1 PERS/PPSS Up Port S I/O, TXD of SCI1 PERS/PPSS Up Port S I/O, MISO of SPI0 PERS/PPSS Up Port S I/O, MOSI of SPI0 PERS/PPSS Up Port S I/O, SCK of SPI0 PERS/PPSS Up Port S I/O, SS of SPI0 RESET pin DOWN Test input PERJ/PPSJ Up Port J I/O, interrupt PERJ/PPSJ Up Port J I/O, interrupt PERM/PPSM Disabled Port M I/O, SCK of SPI0 PERM/PPSM Disabled Port M I/O, MOSI of SPI0 PERM/PPSM Disabled Port M I/O, SS of SPI0 PERM/PPSM Disabled Port M I/O, MISO of SPI0 PERM/PPSM Disabled Port M I/O, TX of CAN0, TXD of SCI1 PERM/PPSM Disabled Port M I/O, RX of CAN0, RXD of SCI1 Device Overview S12XS-Family Device Overview S12XS-Family 38 Table 1-6. Pin-Out Summary1 Package Terminal LQFP 112 106 107 108 109 QFP 80 76 77 78 LQFP 64 61 62 63 Function Pin VSSX1 VDDX1 PK7 PP7 2nd Func. — — — KWP7 3rd Func. — — — PWM7 4th Func. — — — — 5th Func. — — — — 110 - - PP6 KWP6 PWM6 — — 111 79 64 PP5 KWP5 PWM5 — — 112 80 - PP4 KWP4 PWM4 — — 1 Table shows a superset of pin functions. Not all functions are available on all derivatives 2 For compatibility to XE-family 3 VRL and VSSA share single pin on 64 package option Power Supply Internal Pull Resistor CTRL Reset State Description — — VDDX VDDX VDDX VDDX VDDX — — — — — — PUCR Up Port K I/O PERP/PPSP Disabled Port P I/O, interrupt, PWM channel PERP/PPSP Disabled Port P I/O, interrupt, PWM channel PERP/PPSP Disabled Port P I/O, interrupt, PWM channel PERP/PPSP Disabled Port P I/O, interrupt, PWM channel S12XS-Family Reference Manual, Rev. 1.03 PRELIMINARY NOTE For devices assembled in 64-pin and 80-pin packages all non-bonded out pins should be configured as outputs after reset in order to avoid current drawn from floating inputs. Refer to Table 1-6 for affected pins. Freescale Semiconductor 1.2.3 Device Overview S12XS-Family Detailed Signal Descriptions NOTE The pin list of the largest package version of each S12XS-Family derivative gives the complete of interface signals that also exist on smaller package options, although some of them are not bonded out. For devices assembled in smaller packages all non-bonded out pins should be configured as outputs after reset in order to avoid current drawn from floating inputs. Refer to Table 1-6 for affected pins. 1.2.3.1 EXTAL, XTAL — Oscillator Pins EXTAL and XTAL are the crystal driver and external clock pins. On reset all the device clocks are derived from the EXTAL input frequency. XTAL is the oscillator output. 1.2.3.2 RESET — External Reset Pin The RESET pin is an active low bidirectional control signal. It acts as an input to initialize the MCU to a known start-up state. As an output it is driven low to indicate when any internal MCU reset source triggers. The RESET pin has an internal pull-up device. 1.2.3.3 TEST — Test Pin This input only pin is reserved for factory test. This pin has a pull-down device. NOTE The TEST pin must be tied to VSS in all applications. 1.2.3.4 BKGD / MODC — Background Debug and Mode Pin The BKGD/MODC pin is used as a pseudo-open-drain pin for the background debug communication. It is used as a MCU operating mode select pin during reset. The state of this pin is latched to the MODC bit at the rising edge of RESET. The BKGD pin has an internal pull-up device. 1.2.3.5 PAD[15:0] / AN[15:0] — Port AD Input Pins of ATD0 PAD[15:0] are general-purpose input or output pins and analog inputs AN[15:0] of the analog-to-digital converter ATD0. 1.2.3.6 PA[7:0] — Port A I/O Pins PA[7:0] are general-purpose input or output pins. 1.2.3.7 PB[7:0] — Port B I/O Pins PB[7:0] are general-purpose input or output pins. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 39 Device Overview S12XS-Family 1.2.3.8 PE7 / ECLKX2 / XCLKS — Port E I/O Pin 7 PE7 is a general-purpose input or output pin. ECLKX2 is a clock output of twice the internal bus frequency. The XCLKS is an input signal which controls whether a crystal in combination with the internal loop controlled Pierce oscillator is used or whether full swing Pierce oscillator/external clock circuitry is used (refer to Section 1.9 Oscillator Configuration). An internal pull-up is enabled during reset. 1.2.3.9 PE[6:5] — Port E I/O Pin 6-5 PE[6:5] are a general-purpose input or output pins. 1.2.3.10 PE4 / ECLK — Port E I/O Pin 4 PE4 is a general-purpose input or output pin. It can be configured to output the internal bus clock ECLK. ECLK can be used as a timing reference. The ECLK output has a programmable prescaler. 1.2.3.11 PE[3:2] — Port E I/O Pin 3 PE[3:2] are a general-purpose input or output pins. 1.2.3.12 PE1 / IRQ — Port E Input Pin 1 PE1 is a general-purpose input pin and the maskable interrupt request input that provides a means of applying asynchronous interrupt requests. This will wake up the MCU from stop or wait mode. 1.2.3.13 PE0 / XIRQ — Port E Input Pin 0 PE0 is a general-purpose input pin and the non-maskable interrupt request input that provides a means of applying asynchronous interrupt requests. This will wake up the MCU from stop or wait mode. The XIRQ interrupt is level sensitive and active low. As XIRQ is level sensitive, while this pin is low the MCU will not enter STOP mode. 1.2.3.14 PH[7:0] / KWH[7:0] — Port H I/O Pins PH[7:0] are a general-purpose input or output pins. They can be configured as keypad wakeup inputs. 1.2.3.15 PJ[7:6] / KWJ[7:6] — PORT J I/O Pins 7-6 PJ[7:6] are a general-purpose input or output pins. They can be configured as keypad wakeup inputs. 1.2.3.16 PJ[1:0] / KWJ[1:0] — PORT J I/O Pins 1-0 PJ[1:0] are a general-purpose input or output pins. They can be configured as keypad wakeup inputs. 1.2.3.17 PK[7,5:0] — Port K I/O Pins 7 and 5-0 PK[7,5:0] are a general-purpose input or output pins. S12XS-Family Reference Manual, Rev. 1.03 40 PRELIMINARY Freescale Semiconductor 1.2.3.18 PM[7:6] — Port M I/O Pins 7-6 PM[7:6] are a general-purpose input or output pins. Device Overview S12XS-Family 1.2.3.19 PM5 / SCK0 — Port M I/O Pin 5 PM5 is a general-purpose input or output pin. It can be configured as the serial clock pin SCK of the serial peripheral interface 0 (SPI0). 1.2.3.20 PM4 / MOSI0 — Port M I/O Pin 4 PM4 is a general-purpose input or output pin. It can be configured as the master output (during master mode) or slave input pin (during slave mode) MOSI for the serial peripheral interface 0 (SPI0). 1.2.3.21 PM3 / SS0 — Port M I/O Pin 3 PM3 is a general-purpose input or output pin. It can be configured as the slave select pin SS of the serial peripheral interface 0 (SPI0). 1.2.3.22 PM2 / MISO0 — Port M I/O Pin 2 PM2 is a general-purpose input or output pin. It can be configured as the master input (during master mode) or slave output pin (during slave mode) MISO for the serial peripheral interface 0 (SPI0). 1.2.3.23 PM1 / TXCAN0 / TXD1 — Port M I/O Pin 1 PM1 is a general-purpose input or output pin. It can be configured as the transmit pin TXCAN of the scalable controller area network controller 0 (CAN0). It can be configured as the transmit pin TXD of serial communication interface 1 (SCI1). 1.2.3.24 PM0 / RXCAN0 / RXD1 — Port M I/O Pin 0 PM0 is a general-purpose input or output pin. It can be configured as the receive pin RXCAN of the scalable controller area network controller 0 (CAN0). It can be configured as the receive pin RXD of serial communication interface 1 (SCI1). 1.2.3.25 PP7 / KWP7 / PWM7 — Port P I/O Pin 7 PP7 is a general-purpose input or output pin. It can be configured as keypad wakeup input. It can be configured as pulse width modulator (PWM) channel 7 output or emergency shutdown input. 1.2.3.26 PP[6:3] / KWP[6:3] / PWM[6:3] — Port P I/O Pins 6-3 PP[6:3] are a general-purpose input or output pins. They can be configured as keypad wakeup inputs. They can be configured as pulse width modulator (PWM) channel 6-3 output. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 41 Device Overview S12XS-Family 1.2.3.27 PP2 / KWP2 / PWM2 / TXD1 / IOC2 — Port P I/O Pin 2 PP2 is a general-purpose input or output pin. It can be configured as a keypad wakeup input. It can be configured as pulse width modulator (PWM) channel 2 output, TIM channel 2 or as the transmit pin TXD of serial communication interface 1 (SCI1). 1.2.3.28 PP1 / KWP1 / PWM1 / IOC1 — Port P I/O Pin 1 PP1 is a general-purpose input or output pin. It can be configured as a keypad wakeup input. It can be configured as pulse width modulator (PWM) channel 1 output, TIM channel 1. 1.2.3.29 PP0 / KWP0 / PWM0 / RXD1 / IOC0 — Port P I/O Pin 0 PP0 is a general-purpose input or output pin. It can be configured as a keypad wakeup input. It can be configured as pulse width modulator (PWM) channel 0 output, TIM channel 0 or as the receive pin RXD of serial communication interface 1 (SCI1). 1.2.3.30 PS7 / SS0 — Port S I/O Pin 7 PS7 is a general-purpose input or output pin. It can be configured as the slave select pin SS of the serial peripheral interface 0 (SPI0). 1.2.3.31 PS6 / SCK0 — Port S I/O Pin 6 PS6 is a general-purpose input or output pin. It can be configured as the serial clock pin SCK of the serial peripheral interface 0 (SPI0). 1.2.3.32 PS5 / MOSI0 — Port S I/O Pin 5 PS5 is a general-purpose input or output pin. It can be configured as master output (during master mode) or slave input pin (during slave mode) MOSI of the serial peripheral interface 0 (SPI0). 1.2.3.33 PS4 / MISO0 — Port S I/O Pin 4 PS4 is a general-purpose input or output pin. It can be configured as master input (during master mode) or slave output pin (during slave mode) MOSI of the serial peripheral interface 0 (SPI0). 1.2.3.34 PS3 / TXD1 — Port S I/O Pin 3 PS3 is a general-purpose input or output pin. It can be configured as the transmit pin TXD of serial communication interface 1 (SCI1). 1.2.3.35 PS2 / RXD1 — Port S I/O Pin 2 PS2 is a general-purpose input or output pin. It can be configured as the receive pin RXD of serial communication interface 1 (SCI1). S12XS-Family Reference Manual, Rev. 1.03 42 PRELIMINARY Freescale Semiconductor Device Overview S12XS-Family 1.2.3.36 PS1 / TXD0 — Port S I/O Pin 1 PS1 is a general-purpose input or output pin. It can be configured as the transmit pin TXD of serial communication interface 0 (SCI0). 1.2.3.37 PS0 / RXD0 — Port S I/O Pin 0 PS0 is a general-purpose input or output pin. It can be configured as the receive pin RXD of serial communication interface 0 (SCI0). 1.2.3.38 PT[7:6] / IOC[7:6] / PWM[7:6] — Port T I/O Pins 7-6 PT[7:6] are general-purpose input or output pins. They can be configured as timer (TIM) channel 7-6 or pulse width modulator (PWM) outputs 7-6 1.2.3.39 PT5 / IOC5 / VREG_API — Port T I/O Pin 5 PT[5] is a general-purpose input or output pin. It can be configured as timer (TIM) channel 5, pulse width modulator (PWM) output 5 or as the VREG_API signal output. 1.2.3.40 PT4 / IOC4 / PWM4 — Port T I/O Pin 4 PT4 is a general-purpose input or output pin. It can be configured as timer (TIM) channel 4 or pulse width modulator (PWM) output 4. 1.2.3.41 PT[3:0] / IOC[3:0] — Port T I/O Pin [3:0] PT[3:0] are a general-purpose input or output pins. They can be configured as timer (TIM) channels 3-0. 1.2.4 Power Supply Pins S12XS-Family power and ground pins are described below. Because fast signal transitions place high, short-duration current demands on the power supply, use bypass capacitors with high-frequency characteristics and place them as close to the MCU as possible. NOTE All VSS pins must be connected together in the application. 1.2.4.1 VDDX[2:1], VSSX[2:1] — Power and Ground Pins for I/O Drivers External power and ground for I/O drivers. Bypass requirements depend on how heavily the MCU pins are loaded. All VDDX pins are connected together internally. All VSSX pins are connected together internally. 1.2.4.2 VDDR — Power Pin for Internal Voltage Regulator Power supply input to the internal voltage regulator. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 43 Device Overview S12XS-Family 1.2.4.3 VDD, VSS2, VSS3 — Core Power Pins The voltage supply of nominally 1.8V is derived from the internal voltage regulator. The return current path is through the VSS2 and VSS3 pins. No static external loading of these pins is permitted. 1.2.4.4 VDDF, VSS1 — NVM Power Pins The voltage supply of nominally 2.8V is derived from the internal voltage regulator. The return current path is through the VSS1 pin. No static external loading of these pins is permitted. 1.2.4.5 VDDA, VSSA — Power Supply Pins for ATD and Voltage Regulator These are the power supply and ground input pins for the analog-to-digital converters and the voltage regulator. 1.2.4.6 VRH, VRL — ATD Reference Voltage Input Pins VRH and VRL are the reference voltage input pins for the analog-to-digital converter. 1.2.4.7 VDDPLL, VSSPLL — Power Supply Pins for PLL These pins provide operating voltage and ground for the oscillator and the phased-locked loop. The voltage supply of nominally 1.8V is derived from the internal voltage regulator. This allows the supply voltage to the oscillator and PLL to be bypassed independently. This voltage is generated by the internal voltage regulator. No static external loading of these pins is permitted. Table 1-7. Power and Ground Connection Summary Mnemonic VDDR VDDX[2:1] VSSX[2:1] VDDA VSSA VRL VRH VDD VSS1, VSS2, VSS3 VDDF Nominal Voltage 5.0 V 5.0 V 0V 5.0 V 0V 0V 5.0 V 1.8 V 0V 2.8 V Description External power supply to internal voltage regulator External power and ground, supply to pin drivers Operating voltage and ground for the analog-to-digital converters and the reference for the internal voltage regulator, allows the supply voltage to the A/D to be bypassed independently. Reference voltages for the analog-to-digital converter. Internal power and ground generated by internal regulator for the internal core. Internal power and ground generated by internal regulator for the internal NVM. S12XS-Family Reference Manual, Rev. 1.03 44 PRELIMINARY Freescale Semiconductor Device Overview S12XS-Family Table 1-7. Power and Ground Connection Summary Mnemonic VDDPLL VSSPLL Nominal Voltage 1.8 V 0V Description Provides operating voltage and ground for the phased-locked loop. This allows the supply voltage to the PLL to be bypassed independently. Internal power and ground generated by internal regulator. S12XS-Family Reference Manual, Rev. 1.03 45 PRELIMINARY Freescale Semiconductor Device Overview S12XS-Family 1.3 System Clock Description The clock and reset generator module (CRG) provides the internal clock signals for the core and all peripheral modules. Figure 1-6 shows the clock connections from the CRG to all modules. Consult the S12XECRG section for details on clock generation. NOTE The XS-family uses the XE-family clock and reset generator module. Therefore all CRG references are related to S12XECRG. SCI0 . . SCI 1 SPI0 CAN0 ATD0 整体时钟连接图 Bus Clock EXTAL XTAL CRG Core Clock Oscillator Clock PIT TIM PIM PWM RAM S12X FLASH Figure 1-6. Clock Connections The system clock can be supplied in several ways enabling a range of system operating frequencies to be supported: • The on-chip phase locked loop (PLL) • the PLL self clocking • the oscillator S12XS-Family Reference Manual, Rev. 1.03 46 PRELIMINARY Freescale Semiconductor Device Overview S12XS-Family The clock generated by the PLL or oscillator provides the main system clock frequencies core clock and bus clock. As shown in Figure 1-6, these system clocks are used throughout the MCU to drive the core, the memories, and the peripherals. The program Flash memory is supplied by the bus clock and the oscillator clock. The oscillator clock is used as a time base to derive the program and erase times for the NVMs. The CAN modules may be configured to have their clock sources derived either from the bus clock or directly from the oscillator clock. This allows the user to select its clock based on the required jitter performance. In order to ensure the presence of the clock the MCU includes an on-chip clock monitor connected to the output of the oscillator. The clock monitor can be configured to invoke the PLL self-clocking mode or to generate a system reset if it is allowed to time out as a result of no oscillator clock being present. In addition to the clock monitor, the MCU also provides a clock quality checker which performs a more accurate check of the clock. The clock quality checker counts a predetermined number of clock edges within a defined time window to insure that the clock is running. The checker can be invoked following specific events such as on wake-up or clock monitor failure. 1.4 Modes of Operation The MCU can operate in different modes. These are described in 1.4.1 Chip Configuration Summary. The MCU can operate in different power modes to facilitate power saving when full system performance is not required. These are described in 1.4.2 Power Modes. Some modules feature a software programmable option to freeze the module status whilst the background debug module is active to facilitate debugging. This is described in 1.4.3 Freeze Mode. 1.4.1 Chip Configuration Summary The different modes and the security state of the MCU affect the debug features (enabled or disabled). The operating mode out of reset is determined by the state of the MODC signal during reset (see Table 18). The MODC bit in the MODE register shows the current operating mode and provides limited mode switching during operation. The state of the MODC signal is latched into this bit on the rising edge of RESET. Table 1-8. Chip Modes Chip Modes Normal single chip Special single chip MODC 1 0 1.4.1.1 Normal Single-Chip Mode This mode is intended for normal device operation. The opcode from the on-chip memory is being executed after reset (requires the reset vector to be programmed correctly). The processor program is executed from internal memory. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 47 Device Overview S12XS-Family 1.4.1.2 Special Single-Chip Mode This mode is used for debugging single-chip operation, boot-strapping, or security related operations. The background debug module BDM is active in this mode. The CPU executes a monitor program located in an on-chip ROM. BDM firmware waits for additional serial commands through the BKGD pin. 1.4.2 Power Modes The MCU features two main low-power modes. Consult the respective section for module specific behavior in system stop, system pseudo stop, and system wait mode. An important source of information about the clock system is the Clock and Reset Generator section (CRG). 1.4.2.1 System Stop Modes The system stop modes are entered if the CPU executes the STOP instruction unless an NVM command is active. Depending on the state of the PSTP bit in the CLKSEL register the MCU goes into pseudo stop mode or full stop mode. Please refer to CRG section. Asserting RESET, XIRQ, IRQ or any other interrupt that is not masked exits system stop modes. System stop modes can be exited by CPU activity, depending on the configuration of the interrupt request. If the CPU executes the STOP instruction whilst an NVM command is being processed, then the system clocks continue running until NVM activity is completed. If a non-masked interrupt occurs within this time then the system does not effectively enter stop mode although the STOP instruction has been executed. 1.4.2.2 Full Stop Mode The oscillator is stopped in this mode. By default all clocks are switched off and all counters and dividers remain frozen. The Autonomous Periodic Interrupt (API) and ATD module may be enabled to self wake the device. A Fast wake up mode is available to allow the device to wake from Full Stop mode immediately on the PLL internal clock without starting the oscillator clock. 1.4.2.3 Pseudo Stop Mode In this mode the system clocks are stopped but the oscillator is still running and the real time interrupt (RTI) and watchdog (COP), API and ATD modules may be enabled. Other peripherals are turned off. This mode consumes more current than system stop mode but, as the oscillator continues to run, the full speed wake up time from this mode is significantly shorter. 1.4.2.4 Wait Mode This mode is entered when the CPU executes the WAI instruction. In this mode the CPU will not execute instructions. The internal CPU clock is switched off. All peripherals can be active in system wait mode. For further power consumption the peripherals can individually turn off their local clocks. Asserting RESET, XIRQ, IRQ or any other interrupt that is not masked ends system wait mode. S12XS-Family Reference Manual, Rev. 1.03 48 PRELIMINARY Freescale Semiconductor Device Overview S12XS-Family 1.4.2.5 Run Mode Although this is not a low-power mode, unused peripheral modules should not be enabled in order to save power. 1.4.3 Freeze Mode The timer module, pulse width modulator, analog-to-digital converters, and the periodic interrupt timer provide a software programmable option to freeze the module status when the background debug module is active. This is useful when debugging application software. For detailed description of the behavior of the ATD, TIM, PWM, and PIT when the background debug module is active consult the corresponding section. 1.5 Security The MCU security mechanism prevents unauthorized access to the Flash memory. For a detailed description of the security features refer to the S12XS9SEC section. 1.6 Resets and Interrupts Consult the CPU12/CPU12X Reference Manual and the S12XINT section for information on exception processing. NOTE When referring to the S12XINT section please be aware that the XS-family neither features an XGATE nor an MPU module. 1.6.1 Resets Resets are explained in detail in the Clock Reset Generator (S12XECRG) section. Table 1-9. Reset Sources and Vector Locations Vector Address Reset Source CCR Mask Local Enable $FFFE $FFFE $FFFE $FFFE $FFFC $FFFA Power-On Reset (POR) Low Voltage Reset (LVR) External pin RESET Illegal Address Reset Clock monitor reset COP watchdog reset None None None None None None None None None None PLLCTL (CME, SCME) COP rate select 1.6.2 Vectors Table 1-10 lists all interrupt sources and vectors in the default order of priority. The interrupt module (S12XINT) provides an interrupt vector base register (IVBR) to relocate the vectors. Associated with each S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 49 Device Overview S12XS-Family I-bit maskable service request is a configuration register. It selects if the service request is enabled and the service request priority level. Table 1-10. Interrupt Vector Locations (Sheet 1 of 2) Vector Address1 Vector base + $F8 Vector base+ $F6 Vector base+ $F4 Vector base+ $F2 Vector base+ $F0 Vector base+ $EE Vector base + $EC Vector base+ $EA Vector base+ $E8 Vector base+ $E6 Vector base+ $E4 Vector base + $E2 Vector base+ $E0 Vector base+ $DE Vector base+ $DC Vector base + $DA Vector base + $D8 Vector base+ $D6 Vector base + $D4 Vector base + $D2 Vector base + $D0 Vector base + $CE Vector base + $CC Vector base + $CA Vector base + $C8 Vector base + $C6 Vector base + $C4 Vector base + $C2 to Vector base + $BC Interrupt Source Unimplemented instruction trap SWI XIRQ IRQ Real time interrupt TIM timer channel 0 TIM timer channel 1 TIM timer channel 2 TIM timer channel 3 TIM timer channel 4 TIM timer channel 5 TIM timer channel 6 TIM timer channel 7 TIM timer overflow TIM Pulse accumulator A overflow TIM Pulse accumulator input edge SPI0 SCI0 SCI1 ATD0 Port J Port H CRG PLL lock CRG self-clock mode CCR Mask Local Enable STOP WAIT Wake up Wake up None None X Bit I bit I bit None None None IRQCR (IRQEN) CRGINT (RTIE) I bit TIE (C0I) I bit TIE (C1I) I bit TIE (C2I) I bit TIE (C3I) I bit TIE (C4I) I bit TIE (C5I) I bit TIE (C6I) I bit TIE (C7I) I bit TSRC2 (TOF) I bit PACTL (PAOVI) I bit PACTL (PAI) I bit SPI0CR1 (SPIE, SPTIE) I bit SCI0CR2 (TIE, TCIE, RIE, ILIE) I bit SCI1CR2 (TIE, TCIE, RIE, ILIE) I bit ATD0CTL2 (ASCIE) Reserved I bit PIEJ (PIEJ7-PIEJ0) I bit PIEH (PIEH7-PIEH0) Reserved Reserved I bit CRGINT(LOCKIE) I bit CRGINT (SCMIE) — — — — Yes Yes Yes Yes Refer to CRG interrupt section No Yes No Yes No Yes No Yes No Yes No Yes No Yes No Yes No Yes No Yes No Yes No Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Refer to CRG interrupt section Refer to CRG interrupt section Reserved S12XS-Family Reference Manual, Rev. 1.03 50 PRELIMINARY Freescale Semiconductor Device Overview S12XS-Family Table 1-10. Interrupt Vector Locations (Sheet 2 of 2) Vector Address1 Vector base + $BA Vector base + $B8 Vector base + $B6 Vector base + $B4 Interrupt Source FLASH Fault Detect FLASH CAN0 wake-up CAN0 errors Vector base + $B2 CAN0 receive Vector base + $B0 CAN0 transmit Vector base + $AE to Vector base + $90 Vector base + $8E Port P Interrupt Vector base+ $8C PWM emergency shutdown Vector base + $8A to Vector base + $82 Vector base + $80 Low-voltage interrupt (LVI) Vector base + $7E Autonomous periodical interrupt (API) Vector base + $7C High Temperature Interrupt (HTI) Vector base + $7A Periodic interrupt timer channel 0 Vector base + $78 Periodic interrupt timer channel 1 Vector base + $76 Periodic interrupt timer channel 2 Vector base + $74 Periodic interrupt timer channel 3 Vector base + $72 to Vector base + $40 Vector base + $3E ATD0 Compare Interrupt Vector base + $3C to Vector base + $14 Vector base + $12 System Call Interrupt (SYS) Vector base + $10 1 16 bits vector address based Spurious interrupt CCR Mask Local Enable STOP WAIT Wake up Wake up I bit FCNFG2 (SFDIE, DFDIE) No No I bit FCNFG (CCIE) No Yes I bit CAN0RIER (WUPIE) Yes Yes I bit CAN0RIER (CSCIE, OVRIE) No Yes I bit CAN0RIER (RXFIE) No Yes I bit CAN0TIER (TXEIE[2:0]) No Yes Reserved I bit PIEP (PIEP7-PIEP0) I bit PWMSDN (PWMIE) Yes Yes No Yes Reserved I bit VREGCTRL (LVIE) No Yes I bit VREGAPICTRL (APIE) Yes Yes I bit VREGHTCL (HTIE) No Yes I bit PITINTE (PINTE0) No Yes I bit PITINTE (PINTE1) No Yes I bit PITINTE (PINTE2) No Yes I bit PITINTE (PINTE3) No Yes Reserved I bit ATD0CTL2 (ACMPIE) Yes Yes Reserved — None — None — — — — 1.6.3 Effects of Reset When a reset occurs, MCU registers and control bits are initialized. Refer to the respective block sections for register reset states. On each reset, the Flash module executes a reset sequence to load Flash configuration registers. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 51 Device Overview S12XS-Family 1.6.3.1 Flash Configuration Reset Sequence Phase On each reset, the Flash module will hold CPU activity while loading Flash module registers from the Flash memory. If double faults are detected in the reset phase, Flash module protection and security may be active on leaving reset. This is explained in more detail in the Flash module section. 1.6.3.2 Reset While Flash Command Active If a reset occurs while any Flash command is in progress, that command will be immediately aborted. The state of the word being programmed or the sector/block being erased is not guaranteed. 1.6.3.3 I/O Pins Refer to the PIM section for reset configurations of all peripheral module ports. 1.6.3.4 Memory The RAM arrays are not initialized out of reset. 1.6.3.5 COP Configuration The COP time-out rate bits CR[2:0] and the WCOP bit in the COPCTL register are loaded from the Flash register FOPT. See Table 1-11 and Table 1-12 for coding. The FOPT register is loaded from the Flash configuration field byte at global address $7FFF0E during the reset sequence. If the MCU is secured the COP time-out rate is always set to the longest period (CR[2:0] = 111) after any reset into Special Single Chip mode. Table 1-11. Initial COP Rate Configuration NV[2:0] in FOPT Register 000 001 010 011 100 101 110 111 CR[2:0] in COPCTL Register 111 110 101 100 011 010 001 000 Table 1-12. Initial WCOP Configuration NV[3] in FOPT Register 1 0 WCOP in COPCTL Register 0 1 S12XS-Family Reference Manual, Rev. 1.03 52 PRELIMINARY Freescale Semiconductor 1.7 ATD0 Configuration Device Overview S12XS-Family 1.7.1 External Trigger Input Connection The ATD module includes four external trigger inputs ETRIG0, ETRIG1, ETRIG2, and ETRIG3. The external trigger allows the user to synchronize ATD conversion to external trigger events. Table 1-13 shows the connection of the external trigger inputs. Table 1-13. ATD0 External Trigger Sources External Trigger Input ETRIG0 ETRIG1 ETRIG2 ETRIG3 Connectivity Pulse width modulator channel 1 Pulse width modulator channel 3 Periodic interrupt timer hardware trigger 0 Periodic interrupt timer hardware trigger 1 Consult the ATD section for information about the analog-to-digital converter module. References to freeze mode are equivalent to active BDM mode. 1.7.2 ATD0 Channel[17] Connection Further to the 16 externally available channels, ATD0 features an extra channel[17] that is connected to the internal temperature sensor at device level. To access this channel ATD0 must use the channel encoding SC:CD:CC:CB:CA = 1:0:0:0:1 in ATDCTL5. For more temperature sensor information, please refer to 1.8.1 Temperature Sensor Configuration. 1.8 VREG Configuration The device must be configured with the internal voltage regulator enabled. Operation in conjunction with an external voltage regulator is not supported. The API trimming register APITR is loaded from the Flash IFR option field at global address 0x40_00F0 bits[5:0] during the reset sequence. Currently factory programming of this IFR range is not supported. Read access to reserved VREG register space returns “0”. Write accesses have no effect. This device does not support access abort of reserved VREG register space. 1.8.1 Temperature Sensor Configuration The VREG high temperature trimming register bits VREGHTTR[3:0] are loaded from the internal Flash during the reset sequence. To use the high temperature interrupt within the specified limits (THTIA and THTID) these bits must be loaded with 0x8. Currently factory programming is not supported. The device temperature can be monitored on ATD0 channel[17]. The internal bandgap reference voltage can also be mapped to ATD0 analog input channel[17]. The voltage regulator VSEL bit when set, maps the bandgap and, when clear, maps the temperature sensor to ATD0 channel[17]. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 53 Device Overview S12XS-Family 1.9 Oscillator Configuration The XCLKS is an input signal which controls whether a crystal in combination with the internal loop controlled (low power) Pierce oscillator is used or whether full swing Pierce oscillator/external clock circuitry is used. The XCLKS signal selects the oscillator configuration during reset low phase while a clock quality check is ongoing. This is the case for: • Power on reset or low-voltage reset • Clock monitor reset • Any reset while in self-clock mode or full stop mode The selected oscillator configuration is frozen with the rising edge of the RESET pin in any of these above described reset cases. 晶振外围电路 EXTAL MCU C1 Crystal or Ceramic Resonator XTAL C2 VSSPLL Figure 1-7. Loop Controlled Pierce Oscillator Connections (XCLKS = 1) EXTAL MCU XTAL RB RS C1 Crystal or Ceramic Resonator RB=1MΩ ; RS specified by crystal C2 vendor VSSPLL Figure 1-8. Full Swing Pierce Oscillator Connections (XCLKS = 0) EXTAL MCU XTAL CMOS-Compatible External Oscillator Not Connected Figure 1-9. External Clock Connections (XCLKS = 0) S12XS-Family Reference Manual, Rev. 1.03 54 PRELIMINARY Freescale Semiconductor Chapter 2 Port Integration Module (S12XSPIMV1) Revision History Revision Number Revision Date V01.02 19 Jun 2007 V01.03 23 Nov 2007 V01.04 02 Apr 2008 Sections Affected Description of Changes Cleaned-up and corrected table Pin Functions and Priorities Moved notes at DDR registers to Functional Description. Corrected SPI0 routing representation at PTS register. Reworked wordings in several bit descritions. Minor cleanup. Changed PTTRR register description. Corrected reduced drive strength to 1/5 Separated PE1,0 bit descriptions from other PE GPIO 2.1 Introduction 2.1.1 Overview The S12XS Family Port Integration Module establishes the interface between the peripheral modules and the I/O pins for all ports. It controls the electrical pin properties as well as the signal prioritization and multiplexing on shared pins. This document covers: • Port A, B and K used as general purpose I/O • Port E associated with the IRQ, XIRQ interrupt inputs • Port T associated with 1 timer module • Port S associated with 2 SCI module and 1 SPI module • Port M associated with 1 MSCAN • Port P connected to the PWM - inputs can be used as an external interrupt source • Port H and J used as general purpose I/O - inputs can be used as an external interrupt source • Port AD associated with one 16-channel ATD module Most I/O pins can be configured by register bits to select data direction and drive strength, to enable and select pull-up or pull-down devices. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 55 Port Integration Module (S12XSPIMV1) NOTE This document assumes the availabitity of all features (112-pin package option). Some functions are not available on lower pin count package options. Refer to the pin-out summary section. 2.1.2 Features The Port Integration Module includes these distinctive registers: • Data and data direction registers for Ports A, B, E, K, T, S, M, P, H, J, and AD when used as general-purpose I/O • Control registers to enable/disable pull-device and select pull-ups/pull-downs on Ports T, S, M, P, H, and J on per-pin basis • Control registers to enable/disable pull-up devices on Port AD on per-pin basis • Single control register to enable/disable pull-ups on Ports A, B, E, and K on per-port basis and on BKGD pin • Control registers to enable/disable reduced output drive on Ports T, S, M, P, H, J, and AD on perpin basis • Single control register to enable/disable reduced output drive on Ports A, B, E, and K on per-port basis • Control registers to enable/disable open-drain (wired-or) mode on Ports S, and M • Interrupt flag register for pin interrupts on Ports P, H, and J • Control register to configure IRQ pin operation • Routing registers to support module port relocation • Free-running clock outputs A standard port pin has the following minimum features: • Input/output selection • 5V output drive with two selectable drive strengths • 5V digital and analog input • Input with selectable pull-up or pull-down device Optional features supported on dedicated pins: • Open drain for wired-or connections • Interrupt inputs with glitch filtering 2.2 External Signal Description This section lists and describes the signals that do connect off-chip. Table 2-1 shows all the pins and their functions that are controlled by the Port Integration Module. Refer to the device definition for the availability of the individual pins in the different package options. S12XS-Family Reference Manual, Rev. 1.03 56 PRELIMINARY Freescale Semiconductor Port Integration Module (S12XSPIMV1) NOTE If there is more than one function associated with a pin, the priority is indicated by the position in the table from top (highest priority) to bottom (lowest priority). Table 2-1. Pin Functions and Priorities Port Pin Name - BKGD A PA[7:0] B PB[7:0] E PE[7] PE[6:5] PE[4] PE[3:2] PE[1] PE[0] K PK[7,5:0] T PT7 PT6 PT5 PT4 PT[3:0] Pin Function & Priority1 MODC 2 BKGD GPIO GPIO XCLKS 2 ECLKX2 GPIO GPIO ECLK GPIO GPIO IRQ GPI XIRQ GPI GPIO IOC7 (PWM7) GPIO IOC6 (PWM6) GPIO IOC5 (PWM5) VREG_API GPIO IOC4 (PWM4) GPIO IOC[3:0] GPIO I/O Description I MODC input during RESET I/O S12X_BDM communication pin I/O General purpose I/O General purpose I External clock selection input during RESET O Free-running clock at core clock rate (ECLK x 2) I/O General purpose I/O General purpose O Free-running clock at bus clock rate or programmable down- scaled bus clock I/O General purpose I/O General purpose I Maskable level- or falling edge-sensitive interrupt I General-purpose I Non-maskable level-sensitive interrupt I General-purpose I/O General purpose I/O Timer Channel 7 I/O Pulse Width Modulator channel 7; emergency shut-down I/O General purpose I/O Timer Channel 6 O Pulse Width Modulator channel 6 I/O General purpose I/O Timer Channel 5 O Pulse Width Modulator channel 5 O VREG Autonomous Periodical Interrupt Clock I/O General purpose I/O Timer Channel 4 O Pulse Width Modulatort channel 4 I/O General purpose I/O Timer Channel 3 - 0 I/O General purpose Pin Function after Reset BKGD GPIO GPIO GPIO GPIO GPIO S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 57 Port Integration Module (S12XSPIMV1) Port Pin Name S PS7 PS6 PS5 PS4 PS3 PS2 PS1 PS0 M PM[7:6] PM5 PM4 PM3 PM2 PM1 PM0 Pin Function & Priority1 SS0 GPIO SCK0 GPIO MOSI0 GPIO MISO0 GPIO TXD1 GPIO RXD1 GPIO TXD0 GPIO RXD0 GPIO GPIO (SCK0) GPIO (MOSI0) GPIO (SS0) GPIO (MISO0) GPIO TXCAN0 (TXD1) GPIO RXCAN0 (RXD1) GPIO I/O Description Pin Function after Reset I/O Serial Peripheral Interface 0 slave select output in master mode, input in slave mode or master mode. GPIO I/O General purpose I/O Serial Peripheral Interface 0 serial clock pin I/O General purpose I/O Serial Peripheral Interface 0 master out/slave in pin I/O General purpose I/O Serial Peripheral Interface 0 master in/slave out pin I/O General purpose O Serial Communication Interface 1 transmit pin I/O General purpose I Serial Communication Interface 1 receive pin I/O General purpose O Serial Communication Interface 0 transmit pin I/O General purpose I Serial Communication Interface 0 receive pin I/O General purpose I/O General purpose I/O Serial Peripheral Interface 0 serial clock pin I/O General purpose I/O Serial Peripheral Interface 0 master out/slave in pin I/O General purpose I/O Serial Peripheral Interface 0 slave select output in master mode, input in slave mode or master mode. I/O General purpose GPIO I/O Serial Peripheral Interface 0 master in/slave out pin I/O General purpose O MSCAN0 transmit pin O Serial Communication Interface 1 transmit pin I/O General purpose I MSCAN0 receive pin I Serial Communication Interface 1 transmit pin I/O General purpose S12XS-Family Reference Manual, Rev. 1.03 58 PRELIMINARY Freescale Semiconductor Port Integration Module (S12XSPIMV1) Port Pin Name Pin Function & Priority1 I/O Description P PP7 PWM7 I/O Pulse Width Modulator channel 7; emergency shut-down GPIO/KWP7 I/O General purpose; with interrupt PP[6:3] PWM[6:3] O Pulse Width Modulator channel 6 - 3 GPIO/KWP[6:3] I/O General purpose; with interrupt PP2 PWM2 O Pulse Width Modulator channel 2 (IOC2) I/O Timer Channel 2 (TXD1) O Serial Communication Interface 1 transmit pin GPIO/KWP2 I/O General purpose; with interrupt PP1 PWM1 O Pulse Width Modulator channel 1 (IOC1) I/O Timer Channel 1 GPIO/KWP1 I/O General purpose; with interrupt PP0 PWM0 O Pulse Width Modulator channel 0 (IOC0) I/O Timer Channel 0 (RXD1) I Serial Communication Interface 1 transmit pin GPIO/KWP0 I/O General purpose; with interrupt H PH[7:0] GPIO/KWH[7:0] I/O General purpose; with interrupt J PJ[7:6] GPIO/KWJ[7:6] I/O General purpose; with interrupt PJ[1:0] GPIO/KWJ[1:0] I/O General purpose; with interrupt AD PAD[15:0] GPIO I/O General purpose AN[15:0] I ATD analog 1 Signals in brackets denote alternative module routing pins. 2 Function active when RESET asserted. 2.3 Memory Map and Register Definition This section provides a detailed description of all Port Integration Module registers. Pin Function after Reset GPIO GPIO GPIO GPIO 2.3.1 Memory Map Table 2-2 shows the register map of the Port Integration Module. Table 2-2. Block Memory Map Port Offset or Address Register A 0x0000 PORTA—Port A Data Register B 0x0001 PORTB—Port B Data Register 0x0002 DDRA—Port A Data Direction Register 0x0003 DDRB—Port B Data Direction Register 0x0004 : 0x0007 PIM Reserved Access Reset Value Section/Page R/W 0x00 R/W 0x00 R/W 0x00 R/W 0x00 R 0x00 2.3.3/2-70 2.3.4/2-70 2.3.5/2-71 2.3.6/2-71 2.3.7/2-72 S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 59 Port Integration Module (S12XSPIMV1) Table 2-2. Block Memory Map (continued) Port Offset or Address Register E 0x0008 PORTE—Port E Data Register 0x0009 0x000A : 0x000B DDRE—Port E Data Direction Register Non-PIM address range2 A 0x000C PUCR—Pull-up Up Control Register B E 0x000D RDRIV—Reduced Drive Register K 0x000E : 0x001B Non-PIM address range2 E 0x001C ECLKCTL—ECLK Control Register 0x001D PIM Reserved 0x001E IRQCR—IRQ Control Register 0x001F 0x0020 : 0x0031 PIM Reserved Non-PIM address range2 K 0x0032 PORTK—Port K Data Register 0x0033 0x0034 : 0x023F DDRK—Port K Data Direction Register Non-PIM address range2 T 0x0240 PTT—Port T Data Register 0x0241 PTIT—Port T Input Register 0x0242 DDRT—Port T Data Direction Register 0x0243 RDRT—Port T Reduced Drive Register 0x0244 PERT—Port T Pull Device Enable Register 0x0245 PPST—Port T Polarity Select Register 0x0246 PIM Reserved 0x0247 Port T Routing Register Access Reset Value Section/Page R/W1 R/W1 - 0x00 0x00 - 2.3.8/2-72 2.3.9/2-73 - R/W1 R/W1 - 0xD0 0x00 - 2.3.10/2-74 2.3.11/2-75 - R/W1 0b3100_0000 R R/W1 0x00 0x40 R 0x00 - - 2.3.12/2-76 2.3.13/2-77 2.3.14/2-78 2.3.15/2-78 - R/W 0x00 2.3.16/2-79 R/W 0x00 2.3.17/2-79 - - - R/W 0x00 2.3.18/2-80 R 4 2.3.19/2-81 R/W 0x00 2.3.20/2-81 R/W 0x00 2.3.21/2-82 R/W 0x00 2.3.22/2-83 R/W 0x00 2.3.23/2-83 R 0x00 2.3.24/2-84 R/W 0x00 2.3.25/2-84 S12XS-Family Reference Manual, Rev. 1.03 60 PRELIMINARY Freescale Semiconductor Port Integration Module (S12XSPIMV1) Table 2-2. Block Memory Map (continued) Port Offset or Address Register S 0x0248 PTS—Port S Data Register 0x0249 PTIS—Port S Input Register 0x024A DDRS—Port S Data Direction Register 0x024B RDRS—Port S Reduced Drive Register 0x024C PERS—Port S Pull Device Enable Register 0x024D PTPS—Port S Polarity Select Register 0x024E WOMS—Port S Wired-Or Mode Register 0x024F PIM Reserved M 0x0250 PTM—Port M Data Register 0x0251 PTIM—Port M Input Register 0x0252 DDRM—Port M Data Direction Register 0x0253 RDRM—Port M Reduced Drive Register 0x0254 PERM—Port M Pull Device Enable Register 0x0255 PPSM—Port M Polarity Select Register 0x0256 WOMM—Port M Wired-Or Mode Register 0x0257 MODRR—Module Routing Register P 0x0258 PTP—Port P Data Register 0x0259 PTIP—Port P Input Register 0x025A DDRP—Port P Data Direction Register 0x025B RDRP—Port P Reduced Drive Register 0x025C PERP—Port P Pull Device Enable Register 0x025D PTPP—Port P Polarity Select Register 0x025E PIEP—Port P Interrupt Enable Register 0x025F PIFP—Port P Interrupt Flag Register H 0x0260 PTH—Port H Data Register 0x0261 PTIH—Port H Input Register 0x0262 DDRH—Port H Data Direction Register 0x0263 RDRH—Port H Reduced Drive Register 0x0264 PERH—Port H Pull Device Enable Register 0x0265 PPSH—Port H Polarity Select Register 0x0266 PIEH—Port H Interrupt Enable Register 0x0267 PIFH—Port H Interrupt Flag Register Access Reset Value Section/Page R/W 0x00 2.3.26/2-85 R 4 2.3.27/2-87 R/W 0x00 2.3.28/2-87 R/W 0x00 2.3.29/2-88 R/W 0xFF 2.3.30/2-89 R/W 0x00 2.3.31/2-89 R/W 0x00 2.3.32/2-90 R 0x00 2.3.33/2-90 R/W 0x00 2.3.34/2-91 R 4 2.3.35/2-92 R/W 0x00 2.3.36/2-93 R/W 0x00 2.3.37/2-94 R/W 0x00 2.3.38/2-94 R/W 0x00 2.3.39/2-95 R/W 0x00 2.3.40/2-95 R/W 0x00 2.3.41/2-96 R/W 0x00 2.3.42/2-97 R 4 2.3.43/2-98 R/W 0x00 2.3.44/2-99 R/W 0x00 2.3.45/2-100 R/W 0x00 2.3.46/2-100 R/W 0x00 2.3.47/2-101 R/W 0x00 2.3.48/2-101 R/W 0x00 2.3.49/2-102 R/W 0x00 2.3.50/2-102 R 4 2.3.51/2-103 R/W 0x00 2.3.52/2-103 R/W 0x00 2.3.53/2-104 R/W 0x00 2.3.54/2-104 R/W 0x00 2.3.55/2-105 R/W 0x00 2.3.56/2-105 R/W 0x00 2.3.57/2-106 S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 61 Port Integration Module (S12XSPIMV1) Table 2-2. Block Memory Map (continued) Port Offset or Address Register Access Reset Value Section/Page J 0x0268 PTJ—Port J Data Register R/W 0x0269 PTIJ—Port J Input Register R 0x026A DDRJ—Port J Data Direction Register R/W 0x026B RDRJ—Port J Reduced Drive Register R/W 0x026C PERJ—Port J Pull Device Enable Register R/W 0x026D PPSJ—Port J Polarity Select Register R/W 0x026E PIEJ—Port J Interrupt Enable Register R/W 0x026F PIFJ—Port J Interrupt Flag Register R/W AD 0x0270 PT0AD0—Port AD0 Data Register 0 R/W 0x0271 PT1AD0—Port AD0 Data Register 1 R/W 0x0272 DDR0AD0—Port AD0 Data Direction Register 0 R/W 0x0273 DDR1AD0—Port AD0 Data Direction Register 1 R/W 0x0274 RDR0AD0—Port AD0 Reduced Drive Register 0 R/W 0x0275 RDR1AD0—Port AD0 Reduced Drive Register 1 R/W 0x0276 PER0AD0—Port AD0 Pull Up Enable Register 0 R/W 0x0277 PER1AD0—Port AD0 Pull Up Enable Register 1 R/W 0x0278 PIM Reserved R : 0x027F 1 Write access not applicable for one or more register bits. Refer to register description. 2 Refer to memory map in SoC Guide to determine related module. 3 Mode dependent. 4 Read always returns logic level on pins. 0x00 4 0x00 0x00 0xFF 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 2.3.58/2-106 2.3.59/2-107 2.3.60/2-107 2.3.61/2-108 2.3.62/2-108 2.3.63/2-109 2.3.64/2-109 2.3.65/2-110 2.3.66/2-110 2.3.67/2-111 2.3.68/2-111 2.3.69/2-112 2.3.70/2-112 2.3.71/2-113 2.3.72/2-113 2.3.73/2-114 2.3.74/2-114 Register Name Bit 7 6 5 4 0x0000 R PORTA W PA7 PA6 PA5 PA4 0x0001 R PORTB W PB7 PB6 PB5 PB4 0x0002 R DDRA W DDRA7 DDRA6 DDRA5 DDRA4 0x0003 R DDRB W DDRB7 DDRB6 DDRB5 DDRB4 = Unimplemented or Reserved 3 PA3 PB3 DDRA3 DDRB3 2 PA2 PB2 DDRA2 DDRB2 1 PA1 PB1 DDRA1 DDRB1 Bit 0 PA0 PB0 DDRA0 DDRB0 S12XS-Family Reference Manual, Rev. 1.03 62 PRELIMINARY Freescale Semiconductor Port Integration Module (S12XSPIMV1) Register Name Bit 7 6 5 4 3 2 0x0004 R 0 0 0 0 0 0 Reserved W 0x0005 R 0 0 0 0 0 0 Reserved W 0x0006 R 0 0 0 0 0 0 Reserved W 0x0007 R 0 0 0 0 0 0 Reserved W 0x0008 R PORTE W PE7 PE6 PE5 PE4 PE3 PE2 0x0009 R DDRE W DDRE7 0x000A R 0x000B W Non-PIM Address Range 0x000C R PUCR W PUPKE 0x000D R RDRIV W RDPK DDRE6 BKPUE 0 DDRE5 DDRE4 DDRE3 DDRE2 Non-PIM Address Range 0 0 0 PUPEE 0 0 0 RDPE 0x000E– R 0x001B W Non-PIM Address Range Non-PIM Address Range 0x001C R ECLKCTL W NECLK 0x001D R 0 Reserved W NCLKX2 0 DIV16 0 EDIV4 0 EDIV3 0 EDIV2 0 0x001E R 0 0 0 0 IRQCR W IRQE IRQEN 0x001F R 0 0 0 0 0 0 W Reserved = Unimplemented or Reserved 1 0 0 0 0 PE1 0 PUPBE RDPB EDIV1 0 0 0 Bit 0 0 0 0 0 PE0 0 PUPAE RDPA EDIV0 0 0 0 S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 63 Port Integration Module (S12XSPIMV1) Register Name Bit 7 6 5 4 3 2 0x0020– R 0x0031 W Non-PIM Address Range Non-PIM Address Range 0x0032 R 0 PORTK W PK7 PK5 PK4 PK3 PK2 0x0033 R 0 DDRK W DDRK7 DDRK5 DDRK4 DDRK3 DDRK2 0x0034– R 0x023F W Non-PIM Address Range Non-PIM Address Range 0x0240 R PTT W PTT7 0x0241 R PTIT W PTIT7 0x0242 R DDRT W DDRT7 PTT6 PTIT6 DDRT6 PTT5 PTIT5 DDRT5 PTT4 PTIT4 DDRT4 PTT3 PTIT3 DDRT3 PTT2 PTIT2 DDRT2 0x0243 R RDRT W RDRT7 0x0244 R PERT W PERT7 0x0245 R PPST W PPST7 RDRT6 PERT6 PPST6 RDRT5 PERT5 PPST5 RDRT4 PERT4 PPST4 RDRT3 PERT3 PPST3 RDRT2 PERT2 PPST2 0x0246 R 0 Reserved W 0x0247 R PTTRR W PTTRR7 0x0248 R PTS W PTS7 0 PTTRR6 PTS6 0 PTTRR5 PTS5 0 PTTRR4 PTS4 0 0 PTS3 0 PTTRR2 PTS2 0x0249 R PTIS W PTIS7 PTIS6 PTIS5 PTIS4 = Unimplemented or Reserved PTIS3 PTIS2 1 PK1 DDRK1 PTT1 PTIT1 DDRT1 RDRT1 PERT1 PPST1 0 PTTRR1 PTS1 PTIS1 Bit 0 PK0 DDRK0 PTT0 PTIT0 DDRT0 RDRT0 PERT0 PPST0 0 PTTRR0 PTS0 PTIS0 S12XS-Family Reference Manual, Rev. 1.03 64 PRELIMINARY Freescale Semiconductor Port Integration Module (S12XSPIMV1) Register Name 0x024A R DDRS W Bit 7 DDRS7 6 DDRS6 5 DDRS5 4 DDRS4 0x024B R RDRS W RDRS7 RDRS6 RDRS5 RDRS4 0x024C R PERS W PERS7 PERS6 PERS5 PERS4 0x024D R PPSS W PPSS7 PPSS6 PPSS5 PPSS4 0x024E R WOMS W WOMS7 WOMS6 WOMS5 WOMS4 0x024F R 0 0 0 0 Reserved W 0x0250 R PTM W PTM7 PTM6 PTM5 PTM4 0x0251 R PTIM7 PTIM W PTIM6 PTIM5 PTIM4 0x0252 R DDRM W DDRM7 DDRM6 DDRM5 DDRM4 0x0253 R RDRM W RDRM7 RDRM6 RDRM5 RDRM4 0x0254 R PERM W PERM7 PERM6 PERM5 PERM4 0x0255 R PPSM W PPSM7 PPSM6 PPSM5 PPSM4 0x0256 R WOMM W WOMM7 WOMM6 WOMM5 WOMM4 0x0257 R 0 MODRR W MODRR7 MODRR6 MODRR4 0x0258 R PTP W PTP7 PTP6 PTP5 PTP4 0x0259 R PTIP W PTIP7 PTIP6 PTIP5 PTIP4 = Unimplemented or Reserved 3 DDRS3 RDRS3 PERS3 PPSS3 WOMS3 0 PTM3 PTIM3 DDRM3 RDRM3 PERM3 PPSM3 WOMM3 0 PTP3 PTIP3 2 DDRS2 RDRS2 PERS2 PPSS2 WOMS2 0 PTM2 PTIM2 DDRM2 RDRM2 PERM2 PPSM2 WOMM2 0 PTP2 PTIP2 1 DDRS1 RDRS1 PERS1 PPSS1 WOMS1 0 PTM1 PTIM1 DDRM1 RDRM1 PERM1 PPSM1 WOMM1 0 PTP1 PTIP1 Bit 0 DDRS0 RDRS0 PERS0 PPSS0 WOMS0 0 PTM0 PTIM0 DDRM0 RDRM0 PERM0 PPSM0 WOMM0 0 PTP0 PTIP0 S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 65 Port Integration Module (S12XSPIMV1) Register Name Bit 7 6 5 4 0x025A R DDRP W DDRP7 DDRP6 DDRP5 DDRP4 0x025B R RDRP W RDRP7 0x025C R PERP W PERP7 0x025D R PPSP W PPSP7 RDRP6 PERP6 PPSP6 RDRP5 PERP5 PPSP5 RDRP4 PERP4 PPSP4 0x025E R PIEP W PIEP7 0x025F R PIFP W PIFP7 0x0260 R PTH W PTH7 PIEP6 PIFP6 PTH6 PIEP5 PIFP5 PTH5 PIEP4 PIFP4 PTH4 0x0261 R PTIH7 PTIH W 0x0262 R DDRH W DDRH7 0x0263 R RDRH W RDRH7 PTIH6 DDRH6 RDRH6 PTIH5 DDRH5 RDRH5 PTIH4 DDRH4 RDRH4 0x0264 R PERH W PERH7 0x0265 R PPSH W PPSH7 0x0266 R PIEH W PIEH7 PERH6 PPSH6 PIEH6 PERH5 PPSH5 PIEH5 PERH4 PPSH4 PIEH4 0x0267 R PIFH W PIFH7 0x0268 R PTJ W PTJ7 PIFH6 PIFH5 PIFH4 0 0 PTJ6 = Unimplemented or Reserved 3 DDRP3 RDRP3 PERP3 PPSP3 PIEP3 PIFP3 PTH3 PTIH3 DDRH3 RDRH3 PERH3 PPSH3 PIEH3 PIFH3 0 2 DDRP2 RDRP2 PERP2 PPSP2 PIEP2 PIFP2 PTH2 PTIH2 DDRH2 RDRH2 PERH2 PPSH2 PIEH2 PIFH2 0 1 DDRP1 RDRP1 PERP1 PPSP1 PIEP1 PIFP1 PTH1 PTIH1 DDRH1 RDRH1 PERH1 PPSH1 PIEH1 PIFH1 PTJ1 Bit 0 DDRP0 RDRP0 PERP0 PPSP0 PIEP0 PIFP0 PTH0 PTIH0 DDRH0 RDRH0 PERH0 PPSH0 PIEH0 PIFH0 PTJ0 S12XS-Family Reference Manual, Rev. 1.03 66 PRELIMINARY Freescale Semiconductor Port Integration Module (S12XSPIMV1) Register Name Bit 7 6 5 4 3 2 1 Bit 0 0x0269 R PTIJ7 PTIJ6 0 0 0 0 PTIJ1 PTIJ0 PTIJ W 0x026A R 0 0 0 0 DDRJ W DDRJ7 DDRJ6 DDRJ1 DDRJ0 0x026B R 0 0 0 0 RDRJ W RDRJ7 RDRJ6 RDRJ1 RDRJ0 0x026C R 0 0 0 0 PERJ W PERJ7 PERJ6 PERJ1 PERJ0 0x026D R 0 0 0 0 PPSJ W PPSJ7 PPSJ6 PPSJ1 PPSJ0 0x026E R 0 0 0 0 PIEJ W PIEJ7 PIEJ6 PIEJ1 PIEJ0 0x026F R 0 0 0 0 PIFJ W PIFJ7 PIFJ6 PIFJ1 PIFJ0 0x0270 R PT0AD0 W PT0AD07 PT0AD06 PT0AD05 PT0AD04 PT0AD03 PT0AD02 PT0AD01 PT0AD00 0x0271 R PT1AD0 W PT1AD07 PT1AD06 PT1AD05 PT1AD04 PT1AD03 PT1AD02 PT1AD01 PT1AD00 0x0272 R DDR0AD0 W DDR0AD07 DDR0AD06 DDR0AD05 DDR0AD04 DDR0AD03 DDR0AD02 DDR0AD01 DDR0AD00 0x0273 R DDR1AD0 W DDR1AD07 DDR1AD06 DDR1AD05 DDR1AD04 DDR1AD03 DDR1AD02 DDR1AD01 DDR1AD00 0x0274 R RDR0AD0 W RDR0AD07 RDR0AD06 RDR0AD05 RDR0AD04 RDR0AD03 RDR0AD02 RDR0AD01 RDR0AD00 0x0275 R RDR1AD0 W RDR1AD07 RDR1AD06 RDR1AD05 RDR1AD04 RDR1AD03 RDR1AD02 RDR1AD01 RDR1AD00 0x0276 R PER0AD0 W PER0AD07 PER0AD06 PER0AD05 PER0AD04 PER0AD03 PER0AD02 PER0AD01 PER0AD00 0x0277 R PER1AD0 W PER1AD07 PER1AD06 PER1AD05 PER1AD04 PER1AD03 PER1AD02 PER1AD01 PER1AD00 0x0278 R 0 0 0 0 0 0 0 0 Reserved W = Unimplemented or Reserved S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 67 Port Integration Module (S12XSPIMV1) Register Name Bit 7 6 5 4 3 2 1 Bit 0 0x0279 R 0 0 0 0 0 0 0 0 Reserved W 0x027A R 0 0 0 0 0 0 0 0 Reserved W 0x027B R 0 0 0 0 0 0 0 0 Reserved W 0x027C R 0 0 0 0 0 0 0 0 Reserved W 0x027D R 0 0 0 0 0 0 0 0 Reserved W 0x027E R 0 0 0 0 0 0 0 0 Reserved W 0x027F R 0 0 0 0 0 0 0 0 Reserved W = Unimplemented or Reserved 2.3.2 Register Descriptions The following table summarizes the effect of the various configuration bits, i.e. data direction (DDR), output level (IO), reduced drive (RDR), pull enable (PE), pull select (PS) on the pin function and pull device activity. The configuration bit PS is used for two purposes: 1. Configure the sensitive interrupt edge (rising or falling), if interrupt is enabled. 2. Select either a pull-up or pull-down device if PE is active. S12XS-Family Reference Manual, Rev. 1.03 68 PRELIMINARY Freescale Semiconductor Port Integration Module (S12XSPIMV1) Table 2-3. Pin Configuration Summary DDR IO RDR PE PS1 IE2 Function 0 x x 0 x 0 x x 1 0 0 x x 1 1 0 x x 0 0 0 x x 0 1 0 x x 1 0 0 x x 1 1 1 0 0 x x 1 1 0 x x 1 0 1 x x 1 1 1 x x 1 0 0 x 0 1 1 0 x 1 1 0 1 x 0 1 1 1 x 1 1 Always “0” on Port A, B, E, K, and AD. 2 Applicable only on Port P, H, and J. 0 Input 0 Input 0 Input 1 Input 1 Input 1 Input 1 Input 0 Output, full drive to 0 0 Output, full drive to 1 0 Output, reduced drive to 0 0 Output, reduced drive to 1 1 Output, full drive to 0 1 Output, full drive to 1 1 Output, reduced drive to 0 1 Output, reduced drive to 1 Pull Device Disabled Pull Up Pull Down Disabled Disabled Pull Up Pull Down Disabled Disabled Disabled Disabled Disabled Disabled Disabled Disabled Interrupt Disabled Disabled Disabled Falling edge Rising edge Falling edge Rising edge Disabled Disabled Disabled Disabled Falling edge Rising edge Falling edge Rising edge NOTE All register bits in this module are completely synchronous to internal clocks during a register read. NOTE Figure of port data registers also display the alternative functions if applicable on the related pin as defined in Table 2-1. Names in brackets denote the availability of the function when using a specific routing option. NOTE Figures of module routing registers also display the module instance or module channel associated with the related routing bit. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 69 Port Integration Module (S12XSPIMV1) 2.3.3 Port A Data Register (PORTA) Address 0x0000 (PRR) 7 6 5 4 3 2 R PA7 PA6 PA5 PA4 PA3 PA2 W Reset 0 0 0 0 0 0 Figure 2-1. Port A Data Register (PORTA) 1 Read: Anytime. The data source is depending on the data direction value. Write: Anytime Access: User read/write1 1 0 PA1 PA0 0 0 Field 7-0 PA Table 2-4. PORTA Register Field Descriptions Description Port A general purpose input/output data—Data Register The associated pin can be used as general purpose I/O. In general purpose output mode the register bit value is driven to the pin. If the associated data direction bit is set to 1, a read returns the value of the port register bit, otherwise the buffered pin input state is read. 2.3.4 Port B Data Register (PORTB) Address 0x0001 (PRR) 7 6 5 4 3 2 R PB7 PB6 PB5 PB4 PB3 PB2 W Reset 0 0 0 0 0 0 Figure 2-2. Port B Data Register (PORTB) 1 Read: Anytime. The data source is depending on the data direction value. Write: Anytime Access: User read/write1 1 0 PB1 PB0 0 0 Field 7-0 PB Table 2-5. PORTB Register Field Descriptions Description Port B general purpose input/output data—Data Register The associated pin can be used as general purpose I/O. In general purpose output mode the register bit value is driven to the pin. If the associated data direction bit is set to 1, a read returns the value of the port register bit, otherwise the buffered pin input state is read. S12XS-Family Reference Manual, Rev. 1.03 70 PRELIMINARY Freescale Semiconductor 2.3.5 Port A Data Direction Register (DDRA) Port Integration Module (S12XSPIMV1) Address 0x0002 (PRR) 7 R DDRA7 W 6 DDRA6 5 DDRA5 4 DDRA4 3 DDRA3 2 DDRA2 Reset 0 0 0 0 0 0 Figure 2-3. Port A Data Direction Register (DDRA) 1 Read: Anytime. The data source is depending on the data direction value. Write: Anytime Access: User read/write1 1 0 DDRA1 DDRA0 0 0 Table 2-6. DDRA Register Field Descriptions Field 7-0 DDRA Description Port A Data Direction— This bit determines whether the associated pin is an input or output. 1 Associated pin is configured as output 0 Associated pin is configured as input 2.3.6 Port B Data Direction Register (DDRB) Address 0x0003 (PRR) 7 R DDRB7 W 6 DDRB6 5 DDRB5 4 DDRB4 3 DDRB3 2 DDRB2 Reset 0 0 0 0 0 0 Figure 2-4. Port B Data Direction Register (DDRB) 1 Read: Anytime. The data source is depending on the data direction value. Write: Anytime Table 2-7. DDRB Register Field Descriptions Field 7-0 DDRB Description Port B Data Direction— This bit determines whether the associated pin is an input or output. 1 Associated pin is configured as output 0 Associated pin is configured as input Access: User read/write1 1 0 DDRB1 DDRB0 0 0 S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 71 Port Integration Module (S12XSPIMV1) 2.3.7 PIM Reserved Register Address 0x0004 (PRR) to 0x0007 (PRR) 7 6 5 4 3 2 R 0 0 0 0 0 0 W Reset 0 0 0 0 0 0 = Unimplemented or Reserved 1 Read: Always reads 0x00 Write: Unimplemented Figure 2-5. PIM Reserved Register 2.3.8 Port E Data Register (PORTE) Access: User read1 1 0 0 0 0 0 Address 0x0008 (PRR) Access: User read/write1 7 R PE7 W 6 PE6 5 PE5 4 PE4 3 PE3 2 PE2 1 PE1 0 PE0 Altern. Function XCLKS — — ECLK — — IRQ XIRQ ECLKX2 — — — — — — — Reset 0 0 0 0 0 0 —2 —2 = Unimplemented or Reserved Figure 2-6. Port E Data Register (PORTE) 1 Read: Anytime. The data source is depending on the data direction value. Write: Anytime 2 These registers are reset to zero. Two bus clock cycles after reset release the register values are updated with the associated pin values. S12XS-Family Reference Manual, Rev. 1.03 72 PRELIMINARY Freescale Semiconductor Port Integration Module (S12XSPIMV1) Table 2-8. PORTE Register Field Descriptions Field 7 PE Description Port E general purpose input/output data—Data Register, ECLKX2 output, XCLKS input When not used with the alternative function, the associated pin can be used as general purpose I/O. In general purpose output mode the register bit value is driven to the pin. If the associated data direction bit is set to 1, a read returns the value of the port register bit, otherwise the buffered pin input state is read. • The ECLKX2 output function takes precedence over the general purpose I/O function if enabled. • The external clock selection feature (XCLKS) is only active during RESET=0 6-5, 3-2 PE Port E general purpose input/output data—Data Register The associated pin can be used as general purpose I/O. In general purpose output mode the register bit value is driven to the pin. If the associated data direction bit is set to 1, a read returns the value of the port register bit, otherwise the buffered pin input state is read. 4 Port E general purpose input/output data—Data Register, ECLK output PE When not used with the alternative function, the associated pin can be used as general purpose I/O. In general purpose output mode the register bit value is driven to the pin. If the associated data direction bit is set to 1, a read returns the value of the port register bit, otherwise the buffered pin input state is read. • The ECLK output function takes precedence over the general purpose I/O function if enabled. 1 Port E general purpose input data and interrupt—Data Register, IRQ input. PE This pin can be used as general purpose and IRQ input. 0 Port E general purpose input data and interrupt—Data Register, XIRQ input. PE This pin can be used as general purpose and XIRQ input. 2.3.9 Port E Data Direction Register (DDRE) Address 0x0009 (PRR) 7 R DDRE7 W 6 DDRE6 5 DDRE5 4 DDRE4 3 DDRE3 2 DDRE2 Reset 0 0 0 0 0 0 = Unimplemented or Reserved Figure 2-7. Port E Data Direction Register (DDRE) 1 Read: Anytime. The data source is depending on the data direction value. Write: Anytime Access: User read/write1 1 0 0 0 0 0 S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 73 Port Integration Module (S12XSPIMV1) Table 2-9. DDRE Register Field Descriptions Field 7-2 DDRE Description Port E Data Direction— This bit determines whether the associated pin is an input or output. 1 Associated pin is configured as output 0 Associated pin is configured as input 2.3.10 Ports ABEK, BKGD pin Pull-up Control Register (PUCR) Address 0x000C (PRR) Access: User read/write1 7 6 5 4 3 R 0 0 PUPKE BKPUE PUPEE W 2 1 0 PUPBE Reset 1 1 0 1 0 0 0 = Unimplemented or Reserved Figure 2-8. Ports ABEK, BKGD pin Pull-up Control Register (PUCR) 1 Read:Anytime in single-chip modes. Write:Anytime, except BKPUE which is writable in Special Single-Chip Mode only. 0 PUPAE 0 Table 2-10. PUCR Register Field Descriptions Field Description 7 PUPKE Port K Pull-up Enable—Enable pull-up devices on all port input pins This bit configures whether a pull-up device is activated on all associated port input pins. If a pin is used as output this bit has no effect. 6 BKPUE 1 Pull-up device enabled 0 Pull-up device disabled BKGD pin pull-up Enable—Enable pull-up device on pin This bit configures whether a pull-up device is activated, if the pin is used as input. If a pin is used as output this bit has no effect. 4 PUPEE 1 Pull-up device enabled 0 Pull-up device disabled Port E Pull-up Enable—Enable pull-up devices on all port input pins except pins 5 and 6 This bit configures whether a pull-up device is activated on all associated port input pins. If a pin is used as output this bit has no effect. Pins 5 and 6 have pull-down devices enabled only during reset. This bit has no effect on these pins. 1 Pull-up device enabled 0 Pull-up device disabled S12XS-Family Reference Manual, Rev. 1.03 74 PRELIMINARY Freescale Semiconductor Port Integration Module (S12XSPIMV1) Table 2-10. PUCR Register Field Descriptions (continued) Field Description 1 PUPBE Port B Pull-up Enable—Enable pull-up devices on all port input pins This bit configures whether a pull-up device is activated on all associated port input pins. If a pin is used as output this bit has no effect. 0 PUPAE 1 Pull-up device enabled 0 Pull-up device disabled Port A Pull-up Enable—Enable pull-up devices on all port input pins This bit configures whether a pull-up device is activated on all associated port input pins. If a pin is used as output this bit has no effect. 1 Pull-up device enabled 0 Pull-up device disabled 2.3.11 Ports ABEK Reduced Drive Register (RDRIV) Address 0x000D (PRR) 7 6 5 4 3 2 R 0 0 0 0 RDPK RDPE W Reset 0 0 0 0 0 0 = Unimplemented or Reserved Figure 2-9. Ports ABEK Reduced Drive Register (RDRIV) 1 Read: Anytime. The data source is depending on the data direction value. Write: Anytime Access: User read/write1 1 0 RDPB RDPA 0 0 This register is used to select reduced drive for the pins associated with ports A, B, E, and K. If enabled, the pins drive at approx. 1/5 of the full drive strength. The reduced drive function is independent of which function is being used on a particular pin. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 75 Port Integration Module (S12XSPIMV1) Table 2-11. RDRIV Register Field Descriptions Field 7 RDPK Description Port K reduced drive—Select reduced drive for output port This bit configures the drive strength of all associated port output pins as either full or reduced. If a pin is used as input this bit has no effect. The reduced drive function is independent of which function is being used on a particular pin. 4 RDPE 1 Reduced drive selected (approx. 1/5 of the full drive strength) 0 Full drive strength enabled Port E reduced drive—Select reduced drive for output port This bit configures the drive strength of all associated port output pins as either full or reduced. If a pin is used as input this bit has no effect. The reduced drive function is independent of which function is being used on a particular pin. 1 RDPB 1 Reduced drive selected (approx. 1/5 of the full drive strength) 0 Full drive strength enabled Port B reduced drive—Select reduced drive for output port This bit configures the drive strength of all associated port output pins as either full or reduced. If a pin is used as input this bit has no effect. The reduced drive function is independent of which function is being used on a particular pin. 0 RDPA 1 Reduced drive selected (approx. 1/5 of the full drive strength) 0 Full drive strength enabled Port A reduced drive—Select reduced drive for output port This bit configures the drive strength of all associated port output pins as either full or reduced. If a pin is used as input this bit has no effect. The reduced drive function is independent of which function is being used on a particular pin. 1 Reduced drive selected (approx. 1/5 of the full drive strength) 0 Full drive strength enabled 2.3.12 ECLK Control Register (ECLKCTL) Address 0x001C (PRR) R W Reset: Special single-chip Normal single-chip 7 NECLK Mode Depen- dent 0 1 6 NCLKX2 5 DIV16 4 EDIV4 3 EDIV3 2 EDIV2 1 0 0 0 0 1 0 0 0 0 1 0 0 0 0 = Unimplemented or Reserved Figure 2-10. ECLK Control Register (ECLKCTL) Access: User read/write1 1 0 EDIV1 EDIV0 0 0 0 0 0 0 S12XS-Family Reference Manual, Rev. 1.03 76 PRELIMINARY Freescale Semiconductor 1 Read: Anytime Write: Anytime Port Integration Module (S12XSPIMV1) Table 2-12. ECLKCTL Register Field Descriptions Field Description 7 NECLK No ECLK—Disable ECLK output This bit controls the availability of a free-running clock on the ECLK pin. This clock has a fixed rate of equivalent to the internal bus clock. 1 ECLK disabled 0 ECLK enabled 6 No ECLKX2—Disable ECLKX2 output NCLKX2 This bit controls the availability of a free-running clock on the ECLKX2 pin. This clock has a fixed rate of twice the internal bus clock. 5 DIV16 1 ECLKX2 disabled 0 ECLKX2 enabled Free-running ECLK predivider—Divide by 16 This bit enables a divide-by-16 stage on the selected EDIV rate. 4-0 EDIV 1 Divider enabled: ECLK rate = EDIV rate divided by 16 0 Divider disabled: ECLK rate = EDIV rate Free-running ECLK Divider—Configure ECLK rate These bits determine the rate of the free-running clock on the ECLK pin. 00000 ECLK rate = bus clock rate 00001 ECLK rate = bus clock rate divided by 2 00010 ECLK rate = bus clock rate divided by 3, ... 11111 ECLK rate = bus clock rate divided by 32 2.3.13 PIM Reserved Register Address 0x001D (PRR) 7 6 5 4 3 2 R 0 0 0 0 0 0 W Reset 0 0 0 0 0 0 = Unimplemented or Reserved 1 Read: Always reads 0x00 Write: Unimplemented Figure 2-11. PIM Reserved Register Access: User read1 1 0 0 0 0 0 S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 77 Port Integration Module (S12XSPIMV1) 2.3.14 IRQ Control Register (IRQCR) Address 0x001E 7 6 5 4 3 2 R 0 0 0 0 IRQE IRQEN W Reset 0 1 0 0 0 0 = Unimplemented or Reserved Figure 2-12. IRQ Control Register (IRQCR) 1 Read: See individual bit descriptions below. Write: See individual bit descriptions below. Access: User read/write1 1 0 0 0 0 0 Table 2-13. IRQCR Register Field Descriptions Field 7 IRQE IRQ select edge sensitive only— Special mode: Read or write anytime. Normal mode: Read anytime, write once. Description 6 IRQEN 1 IRQ configured to respond only to falling edges. Falling edges on the IRQ pin will be detected anytime IRQE=1 and will be cleared only upon a reset or the servicing of the IRQ interrupt. 0 IRQ configured for low level recognition. IRQ enable— Read or write anytime. 1 IRQ pin is connected to interrupt logic. 0 IRQ pin is disconnected from interrupt logic. 2.3.15 PIM Reserved Register PIMTEST1 This register is reserved for factory testing of the PIM module and is not available in normal operation. Writing to this register when in special modes can alter the pin functionality. Address 0x001F Access: User read1 7 6 5 4 3 2 1 0 R 0 0 0 0 0 0 0 0 W Reset 0 0 0 0 0 0 0 0 = Unimplemented or Reserved Figure 2-13. PIM Reserved Register 1. Implementation pim_xe.01.01 and later S12XS-Family Reference Manual, Rev. 1.03 78 PRELIMINARY Freescale Semiconductor 1 Read: Always reads 0x00 Write: Unimplemented Port Integration Module (S12XSPIMV1) 2.3.16 Port K Data Register (PORTK) Address 0x0032 (PRR) 7 6 5 4 3 2 R 0 PK7 PK5 PK4 PK3 PK2 W Reset 0 0 0 0 0 0 Figure 2-14. Port K Data Register (PORTK) 1 Read: Anytime. The data source is depending on the data direction value. Write: Anytime Access: User read/write1 1 0 PK1 PK0 0 0 Field 7,5-0 PK Table 2-14. PORTK Register Field Descriptions Description Port K general purpose input/output data—Data Register The associated pin can be used as general purpose I/O. In general purpose output mode the register bit value is driven to the pin. If the associated data direction bit is set to 1, a read returns the value of the port register bit, otherwise the buffered pin input state is read. 2.3.17 Port K Data Direction Register (DDRK) Address 0x0033 (PRR) 7 6 5 4 3 2 R 0 DDRK7 DDRK5 DDRK4 DDRK3 DDRK2 W Reset 0 0 0 0 0 0 Figure 2-15. Port K Data Direction Register (DDRK) 1 Read: Anytime. The data source is depending on the data direction value. Write: Anytime Table 2-15. DDRK Register Field Descriptions Field 7,5-0 DDRK Description Port K Data Direction— This bit determines whether the associated pin is an input or output. 1 Associated pin is configured as output 0 Associated pin is configured as input Access: User read/write1 1 0 DDRK1 DDRK0 0 0 S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 79 Port Integration Module (S12XSPIMV1) 2.3.18 Port T Data Register (PTT) Address 0x0240 7 R PTT7 W 6 PTT6 5 PTT5 4 PTT4 3 PTT3 2 PTT2 Altern. Function IOC7 (PWM7) IOC6 (PWM6) IOC5 (PWM5) IOC4 (PWM4) IOC3 — IOC2 — — — VREG_API — — — Reset 0 0 0 0 0 0 Figure 2-16. Port T Data Register (PTT) 1 Read: Anytime. The data source is depending on the data direction value. Write: Anytime Access: User read/write1 1 0 PTT1 PTT0 IOC1 — — 0 IOC0 — — 0 Table 2-16. PTT Register Field Descriptions Field Description 7-6, 4 PTT Port T general purpose input/output data—Data Register, TIM output, routed PWM output When not used with the alternative function, the associated pin can be used as general purpose I/O. In general purpose output mode the register bit value is driven to the pin. If the associated data direction bit is set to 1, a read returns the value of the port register bit, otherwise the buffered pin input state is read. • The TIM output function takes precedence over the routed PWM and the general purpose I/O function if the related channel is enabled. • The routed PWM function takes precedence over the general purpose I/O function if the related channel is enabled. 5 Port T general purpose input/output data—Data Register, TIM output, routed PWM output, VREG_API output PTT When not used with the alternative function, the associated pin can be used as general purpose I/O. In general purpose output mode the register bit value is driven to the pin. If the associated data direction bit is set to 1, a read returns the value of the port register bit, otherwise the buffered pin input state is read. • The TIM output function takes precedence over the routed PWM, VREG_API function and the general purpose I/O function if the related channel is enabled. • The routed PWM function takes precedence over VREG_API and the general purpose I/O function if the related channel is enabled. • The VREG_API takes precedence over the general purpose I/O function if enabled. 3-0 Port T general purpose input/output data—Data Register, TIM output PTT When not used with the alternative function, the associated pin can be used as general purpose I/O. In general purpose output mode the register bit value is driven to the pin. If the associated data direction bit is set to 1, a read returns the value of the port register bit, otherwise the buffered pin input state is read. • The TIM output function takes precedence over the general purpose I/O function if the related channel is enabled. S12XS-Family Reference Manual, Rev. 1.03 80 PRELIMINARY Freescale Semiconductor 2.3.19 Port T Input Register (PTIT) Port Integration Module (S12XSPIMV1) Address 0x0241 7 R PTIT7 6 PTIT6 5 PTIT5 4 PTIT4 3 PTIT3 2 PTIT2 W Reset u u u u u u = Unimplemented or Reserved u = Unaffected by reset Figure 2-17. Port T Input Register (PTIT) 1 Read: Anytime Write:Never, writes to this register have no effect. Access: User read1 1 PTIT1 0 PTIT0 u u Field 7-0 PTIT Table 2-17. PTIT Register Field Descriptions Description Port T input data— A read always returns the buffered input state of the associated pin. It can be used to detect overload or short circuit conditions on output pins. 2.3.20 Port T Data Direction Register (DDRT) Address 0x0242 R W Reset 7 DDRT7 0 1 Read: Anytime Write: Anytime 6 DDRT6 5 DDRT5 4 DDRT4 3 DDRT3 2 DDRT2 0 0 0 0 0 Figure 2-18. Port T Data Direction Register (DDRT) Access: User read/write1 1 0 DDRT1 DDRT0 0 0 S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 81 Port Integration Module (S12XSPIMV1) Table 2-18. DDRT Register Field Descriptions Field 7-6, 4 DDRT Description Port T data direction— This bit determines whether the pin is an input or output. The TIM forces the I/O state to be an output for a timer port associated with an enabled output compare. Else the routed PWM forces the I/O state to be an output for an enabled channel. In these cases the data direction bit will not change. 5 DDRT 1 Associated pin is configured as output 0 Associated pin is configured as input Port T data direction— This bit determines whether the pin is an input or output. The TIM forces the I/O state to be an output for a timer port associated with an enabled output compare. Else the routed PWM forces the I/O state to be an output for an enabled channel. Else the VREG_API forces the I/O state to be an output if enabled. In these cases the data direction bit will not change. 3-0 DDRT 1 Associated pin is configured as output 0 Associated pin is configured as input Port T data direction— This bit determines whether the pin is an input or output. The TIM forces the I/O state to be an output for a timer port associated with an enabled output compare. In this case the data direction bit will not change. 1 Associated pin is configured as output 0 Associated pin is configured as input 2.3.21 Port T Reduced Drive Register (RDRT) Address 0x0243 R W Reset 7 RDRT7 0 1 Read: Anytime Write: Anytime 6 RDRT6 5 RDRT5 4 RDRT4 3 RDRT3 2 RDRT2 0 0 0 0 0 Figure 2-19. Port T Reduced Drive Register (RDRT) Access: User read/write1 1 0 RDRT1 RDRT0 0 0 Table 2-19. RDRT Register Field Descriptions Field 7-0 RDRT Description Port T reduced drive—Select reduced drive for output pin This bit configures the drive strength of the asscociated output pin as either full or reduced. If a pin is used as input this bit has no effect. The reduced drive function is independent of which function is being used on a particular pin. 1 Reduced drive selected (approx. 1/5 of the full drive strength) 0 Full drive strength enabled S12XS-Family Reference Manual, Rev. 1.03 82 PRELIMINARY Freescale Semiconductor 2.3.22 Port T Pull Device Enable Register (PERT) Port Integration Module (S12XSPIMV1) Address 0x0244 R W Reset 7 PERT7 0 1 Read: Anytime Write: Anytime 6 PERT6 5 PERT5 4 PERT4 3 PERT3 2 PERT2 0 0 0 0 0 Figure 2-20. Port T Pull Device Enable Register (PERT) Access: User read/write1 1 0 PERT1 PERT0 0 0 Table 2-20. PERT Register Field Descriptions Field 7-0 PERT Description Port T pull device enable—Enable pull device on input pin This bit controls whether a pull device on the associated port input pin is active. If a pin is used as output this bit has no effect. The polarity is selected by the related polarity select register bit. 1 Pull device enabled 0 Pull device disabled 2.3.23 Port T Polarity Select Register (PPST) Address 0x0245 R W Reset 7 PPST7 0 1 Read: Anytime Write: Anytime 6 PPST6 5 PPST5 4 PPST4 3 PPST3 2 PPST2 0 0 0 0 0 Figure 2-21. Port T Polarity Select Register (PPST) Access: User read/write1 1 0 PPST1 PPST0 0 0 Table 2-21. PPST Register Field Descriptions Field 7-0 PPST Description Port T pull device select—Configure pull device polarity on input pin This bit selects a pull-up or a pull-down device if enabled on the associated port input pin. 1 A pull-down device is selected 0 A pull-up device is selected S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 83 Port Integration Module (S12XSPIMV1) 2.3.24 PIM Reserved Register Address 0x0246 7 6 5 4 3 2 R 0 0 0 0 0 0 W Reset 0 0 0 0 0 0 = Unimplemented or Reserved 1 Read: Always reads 0x00 Write: Unimplemented Figure 2-22. PIM Reserved Register Access: User read1 1 0 0 0 0 0 2.3.25 Port T Routing Register (PTTRR) Address 0x0247 R W Routing Option Reset 7 PTTRR7 PWM7 0 1 Read: Anytime Write: Anytime 6 5 4 3 2 0 PTTRR6 PTTRR5 PTTRR4 PTTRR2 PWM6 PWM5 PWM4 — IOC2 0 0 0 0 0 = Unimplemented or Reserved Figure 2-23. Port T Routing Register (PTTRR) Access: User read1 1 0 PTTRR1 PTTRR0 IOC1 0 IOC0 0 This register configures the re-routing of PWM and TIM channels on alternative pins. Table 2-22. Port T Routing Register Field Descriptions Field Description 7 PTTRR 6 PTTRR 5 PTTRR Port T peripheral routing— This register controls the routing of PWM channel 7. 1 PWM7 routed to PT7 0 PWM7 routed to PP7 Port T peripheral routing— This register controls the routing of PWM channel 6. 1 PWM6 routed to PT6 0 PWM6 routed to PP6 Port T peripheral routing— This register controls the routing of PWM channel 5. 1 PWM5 routed to PT5 0 PWM5 routed to PP5 S12XS-Family Reference Manual, Rev. 1.03 84 PRELIMINARY Freescale Semiconductor Port Integration Module (S12XSPIMV1) Table 2-22. Port T Routing Register Field Descriptions (continued) Field Description 4 PTTRR 2 PTTRR 1 PTTRR 0 PTTRR Port T peripheral routing— This register controls the routing of PWM channel 4. 1 PWM4 routed to PT4 0 PWM4 routed to PP4 Port T peripheral routing— This register controls the routing of TIM channel 2. 1 IOC2 routed to PP2 0 IOC2 routed to PT2 Port T peripheral routing— This register controls the routing of TIM channel 1. 1 IOC1 routed to PP1 0 IOC1 routed to PT1 Port T peripheral routing— This register controls the routing of TIM channel 0. 1 IOC0 routed to PP0 0 IOC0 routed to PT0 2.3.26 Port S Data Register (PTS) Address 0x0248 7 R PTS7 W 6 PTS6 5 PTS5 4 PTS4 3 PTS3 2 PTS2 Altern. Function SS0 SCK0 MOSI0 MISO0 TXD1 RXD1 Reset 0 0 0 0 0 0 Figure 2-24. Port S Data Register (PTS) 1 Read: Anytime. The data source is depending on the data direction value. Write: Anytime Access: User read/write1 1 0 PTS1 PTS0 TXD0 0 RXD0 0 S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 85 Port Integration Module (S12XSPIMV1) Field 7 PTS 6 PTS 5 PTS 4 PTS 3 PTS 2 PTS Table 2-23. PTS Register Field Descriptions Description Port S general purpose input/output data—Data Register, SPI0 SS input/output When not used with the alternative function, the associated pin can be used as general purpose I/O. In general purpose output mode the register bit value is driven to the pin. If the associated data direction bit is set to 1, a read returns the value of the port register bit, otherwise the buffered pin input state is read. • The SPI0 function takes precedence over the general purpose I/O function if enabled. Port S general purpose input/output data—Data Register, SPI0 SCK input/output When not used with the alternative function, the associated pin can be used as general purpose I/O. In general purpose output mode the register bit value is driven to the pin. If the associated data direction bit is set to 1, a read returns the value of the port register bit, otherwise the buffered pin input state is read. • The SPI0 function takes precedence over the general purpose I/O function if enabled. Port S general purpose input/output data—Data Register, SPI0 MOSI input/output When not used with the alternative function, the associated pin can be used as general purpose I/O. In general purpose output mode the register bit value is driven to the pin. If the associated data direction bit is set to 1, a read returns the value of the port register bit, otherwise the buffered pin input state is read. • The SPI0 function takes precedence over the general purpose I/O function if enabled. Port S general purpose input/output data—Data Register, SPI0 MISO input/output When not used with the alternative function, the associated pin can be used as general purpose I/O. In general purpose output mode the register bit value is driven to the pin. If the associated data direction bit is set to 1, a read returns the value of the port register bit, otherwise the buffered pin input state is read. • The SPI0 function takes precedence over the general purpose I/O function if enabled. Port S general purpose input/output data—Data Register, SCI1 TXD output When not used with the alternative function, the associated pin can be used as general purpose I/O. In general purpose output mode the register bit value is driven to the pin. If the associated data direction bit is set to 1, a read returns the value of the port register bit, otherwise the buffered pin input state is read. • The SCI1 function takes precedence over the general purpose I/O function if enabled. Port S general purpose input/output data—Data Register, SCI1 RXD input When not used with the alternative function, the associated pin can be used as general purpose I/O. In general purpose output mode the register bit value is driven to the pin. If the associated data direction bit is set to 1, a read returns the value of the port register bit, otherwise the buffered pin input state is read. • The SCI1 function takes precedence over the general purpose I/O function if enabled. S12XS-Family Reference Manual, Rev. 1.03 86 PRELIMINARY Freescale Semiconductor Port Integration Module (S12XSPIMV1) Table 2-23. PTS Register Field Descriptions (continued) Field 1 PTS 0 PTS Description Port S general purpose input/output data—Data Register, SCI0 TXD output When not used with the alternative function, the associated pin can be used as general purpose I/O. In general purpose output mode the register bit value is driven to the pin. If the associated data direction bit is set to 1, a read returns the value of the port register bit, otherwise the buffered pin input state is read. • The SCI0 function takes precedence over the general purpose I/O function if enabled. Port S general purpose input/output data—Data Register, SCI0 RXD input When not used with the alternative function, the associated pin can be used as general purpose I/O. In general purpose output mode the register bit value is driven to the pin. If the associated data direction bit is set to 1, a read returns the value of the port register bit, otherwise the buffered pin input state is read. • The SCI0 function takes precedence over the general purpose I/O function if enabled. 2.3.27 Port S Input Register (PTIS) Address 0x0249 7 R PTIS7 6 PTIS6 5 PTIS5 4 PTIS4 3 PTIS3 2 PTIS2 W Reset u u u u u u = Unimplemented or Reserved u = Unaffected by reset Figure 2-25. Port S Input Register (PTIS) 1 Read: Anytime Write:Never, writes to this register have no effect. Access: User read1 1 PTIS1 0 PTIS0 u u Field 7-0 PTIS Table 2-24. PTIS Register Field Descriptions Description Port S input data— A read always returns the buffered input state of the associated pin. It can be used to detect overload or short circuit conditions on output pins. 2.3.28 Port S Data Direction Register (DDRS) Address 0x0249 R W Reset 7 DDRS7 0 6 DDRS6 5 DDRS5 4 DDRS4 3 DDRS3 2 DDRS2 0 0 0 0 0 Figure 2-26. Port S Data Direction Register (DDRS) Freescale Semiconductor S12XS-Family Reference Manual, Rev. 1.03 PRELIMINARY Access: User read/write1 1 0 DDRS1 DDRS0 0 0 87 Port Integration Module (S12XSPIMV1) 1 Read: Anytime Write: Anytime Table 2-25. DDRS Register Field Descriptions Field 7-4 DDRS Description Port S data direction— This bit determines whether the associated pin is an input or output. Depending on the configuration of the enabled SPI0 the I/O state will be forced to be input or output. In this case the data direction bit will not change. 3-2 DDRS 1 Associated pin is configured as output 0 Associated pin is configured as input Port S data direction— This bit determines whether the associated pin is an input or output. Depending on the configuration of the enabled SCI1 the I/O state will be forced to be input or output. In this case the data direction bit will not change. 1-0 DDRS 1 Associated pin is configured as output 0 Associated pin is configured as input Port S data direction— This bit determines whether the associated pin is an input or output. Depending on the configuration of the enabled SCI0 the I/O state will be forced to be input or output. In this case the data direction bit will not change. 1 Associated pin is configured as output 0 Associated pin is configured as input 2.3.29 Port S Reduced Drive Register (RDRS) Address 0x024A R W Reset 7 RDRS7 0 1 Read: Anytime Write: Anytime 6 RDRS6 5 RDRS5 4 RDRS4 3 RDRS3 2 RDRS2 0 0 0 0 0 Figure 2-27. Port S Reduced Drive Register (RDRS) Access: User read/write1 1 0 RDRS1 RDRS0 0 0 Table 2-26. RDRS Register Field Descriptions Field Description 7-0 RDRS Port S reduced drive—Select reduced drive for output pin This bit configures the drive strength of the asscociated output pin as either full or reduced. If a pin is used as input this bit has no effect. The reduced drive function is independent of which function is being used on a particular pin. 1 Reduced drive selected (approx. 1/5 of the full drive strength) 0 Full drive strength enabled S12XS-Family Reference Manual, Rev. 1.03 88 PRELIMINARY Freescale Semiconductor 2.3.30 Port S Pull Device Enable Register (PERS) Port Integration Module (S12XSPIMV1) Address 0x024B R W Reset 7 PERS7 1 1 Read: Anytime Write: Anytime 6 PERS6 5 PERS5 4 PERS4 3 PERS3 2 PERS2 1 1 1 1 1 Figure 2-28. Port S Pull Device Enable Register (PERS) Access: User read/write1 1 0 PERS1 PERS0 1 1 Table 2-27. PERS Register Field Descriptions Field 7-0 PERS Description Port S pull device enable—Enable pull device on input pin or wired-or output pin This bit controls whether a pull device on the associated port input pin is active. If a pin is used as output this bit has only effect if used in wired-or mode. The polarity is selected by the related polarity select register bit. 1 Pull device enabled 0 Pull device disabled 2.3.31 Port S Polarity Select Register (PPSS) Address 0x024C R W Reset 7 PPSS7 0 1 Read: Anytime Write: Anytime 6 PPSS6 5 PPSS5 4 PPSS4 3 PPSS3 2 PPSS2 0 0 0 0 0 Figure 2-29. Port S Polarity Select Register (PPSS) Access: User read/write1 1 0 PPSS1 PPSS0 0 0 Table 2-28. PPSS Register Field Descriptions Field 7-0 PPSS Description Port S pull device select—Configure pull device polarity on input pin This bit selects a pull-up or a pull-down device if enabled on the associated port input pin. 1 A pull-down device is selected 0 A pull-up device is selected S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 89 Port Integration Module (S12XSPIMV1) 2.3.32 Port S Wired-Or Mode Register (WOMS) Address 0x024C R W Reset 7 WOMS7 0 1 Read: Anytime Write: Anytime 6 WOMS6 5 WOMS5 4 WOMS4 3 WOMS3 2 WOMS2 0 0 0 0 0 Figure 2-30. Port S Wired-Or Mode Register (WOMS) Access: User read/write1 1 0 WOMS1 WOMS0 0 0 Table 2-29. WOMS Register Field Descriptions Field Description 7-0 WOMS Port S wired-or mode—Enable open-drain functionality on output pin This bit configures an output pin as wired-or (open-drain) or push-pull. In wired-or mode a logic “0” is driven active low while a logic “1” remains undriven. This allows a multipoint connection of several serial modules. The bit has no influence on pins used as input. 1 Output buffer operates as open-drain output. 0 Output buffer operates as push-pull output. 2.3.33 PIM Reserved Register Address 0x024F 7 6 5 4 3 2 R 0 0 0 0 0 0 W Reset 0 0 0 0 0 0 = Unimplemented or Reserved u = Unaffected by reset 1 Read: Always reads 0x00 Write: Unimplemented Figure 2-31. PIM Reserved Register Access: User read1 1 0 0 0 0 0 S12XS-Family Reference Manual, Rev. 1.03 90 PRELIMINARY Freescale Semiconductor 2.3.34 Port M Data Register (PTM) Port Integration Module (S12XSPIMV1) Address 0x0250 7 R PTM7 W 6 PTM6 5 PTM5 4 PTM4 3 PTM3 2 PTM2 Altern. Function — — (SCK0) (MOSI0) (SS0) (MISO0) — — — — — — Reset 0 0 0 0 0 0 Figure 2-32. Port M Data Register (PTM) 1 Read: Anytime. The data source is depending on the data direction value. Write: Anytime Access: User read/write1 1 0 PTM1 PTM0 TXCAN0 (TXD1) 0 RXCAN0 (RXD1) 0 Field 7-6 PTM 5 PTM 4 PTM 3 PTM Table 2-30. PTM Register Field Descriptions Description Port M general purpose input/output data—Data Register When not used with the alternative function, the associated pin can be used as general purpose I/O. In general purpose output mode the register bit value is driven to the pin. If the associated data direction bit is set to 1, a read returns the value of the port register bit, otherwise the buffered pin input state is read. Port M general purpose input/output data—Data Register, routed SPI0 SCK input/output When not used with the alternative function, the associated pin can be used as general purpose I/O. In general purpose output mode the register bit value is driven to the pin. If the associated data direction bit is set to 1, a read returns the value of the port register bit, otherwise the buffered pin input state is read. • The SPI0 function takes precedence over the general purpose I/O function if enabled. Port M general purpose input/output data—Data Register, routed SPI0 MOSI input/output When not used with the alternative function, the associated pin can be used as general purpose I/O. In general purpose output mode the register bit value is driven to the pin. If the associated data direction bit is set to 1, a read returns the value of the port register bit, otherwise the buffered pin input state is read. • The SPI0 function takes precedence over the general purpose I/O function if enabled. Port M general purpose input/output data—Data Register, routed SPI0 SS input/output When not used with the alternative function, the associated pin can be used as general purpose I/O. In general purpose output mode the register bit value is driven to the pin. If the associated data direction bit is set to 1, a read returns the value of the port register bit, otherwise the buffered pin input state is read. • The SPI0 function takes precedence over the general purpose I/O function if enabled. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 91 Port Integration Module (S12XSPIMV1) Table 2-30. PTM Register Field Descriptions (continued) Field 2 PTM 1 PTM 0 PTM Description Port M general purpose input/output data—Data Register, routed SPI0 MISO input/output When not used with the alternative function, the associated pin can be used as general purpose I/O. In general purpose output mode the register bit value is driven to the pin. If the associated data direction bit is set to 1, a read returns the value of the port register bit, otherwise the buffered pin input state is read. • The SPI0 function takes precedence over the general purpose I/O function if enabled. Port M general purpose input/output data—Data Register, CAN0 TXCAN output, SCI1 TXD output When not used with the alternative function, the associated pin can be used as general purpose I/O. In general purpose output mode the register bit value is driven to the pin. If the associated data direction bit is set to 1, a read returns the value of the port register bit, otherwise the buffered pin input state is read. • The CAN0 function takes precedence over the general purpose I/O function if enabled. • The SCI1 function takes precedence over the general purpose I/O function if enabled. Port M general purpose input/output data—Data Register, CAN0 RXCAN input, SCI1 RXD input When not used with the alternative function, the associated pin can be used as general purpose I/O. In general purpose output mode the register bit value is driven to the pin. If the associated data direction bit is set to 1, a read returns the value of the port register bit, otherwise the buffered pin input state is read. • The CAN0 function takes precedence over the general purpose I/O function if enabled. • The SCI1 function takes precedence over the general purpose I/O function if enabled. 2.3.35 Port M Input Register (PTIM) Address 0x0251 7 R PTIM7 6 PTIM6 5 PTIM5 4 PTIM4 3 PTIM3 2 PTIM2 W Reset u u u u u u = Unimplemented or Reserved u = Unaffected by reset Figure 2-33. Port M Input Register (PTIM) 1 Read: Anytime Write:Never, writes to this register have no effect. Access: User read1 1 PTIM1 0 PTIM0 u u Field 7-0 PTIM Table 2-31. PTIM Register Field Descriptions Description Port M input data— A read always returns the buffered input state of the associated pin. It can be used to detect overload or short circuit conditions on output pins. S12XS-Family Reference Manual, Rev. 1.03 92 PRELIMINARY Freescale Semiconductor 2.3.36 Port M Data Direction Register (DDRM) Port Integration Module (S12XSPIMV1) Address 0x0252 R W Reset 7 DDRM7 0 1 Read: Anytime Write: Anytime 6 DDRM6 5 DDRM5 4 DDRM4 3 DDRM3 2 DDRM2 0 0 0 0 0 Figure 2-34. Port M Data Direction Register (DDRM) Access: User read/write1 1 0 DDRM1 DDRM0 0 0 Table 2-32. DDRM Register Field Descriptions Field 7-6 DDRM Description Port M data direction— This bit determines whether the associated pin is an input or output. 5-2 DDRM 1 Associated pin is configured as output 0 Associated pin is configured as input Port M data direction— This bit determines whether the associated pin is an input or output. Depending on the configuration of the enabled SPI0 the I/O state will be forced to be input or output. In this case the data direction bit will not change. 1 DDRM 1 Associated pin is configured as output 0 Associated pin is configured as input Port M data direction— This bit determines whether the associated pin is an input or output. The enabled CAN0 or SCI1 forces the I/O state to be an output. In this case the data direction bit will not change. 0 DDRM 1 Associated pin is configured as output 0 Associated pin is configured as input Port M data direction— This bit determines whether the associated pin is an input or output. The enabled CAN0 or SCI1 forces the I/O state to be an input. In this case the data direction bit will not change. 1 Associated pin is configured as output 0 Associated pin is configured as input S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 93 Port Integration Module (S12XSPIMV1) 2.3.37 Port M Reduced Drive Register (RDRM) Address 0x0253 R W Reset 7 RDRM7 0 1 Read: Anytime Write: Anytime 6 RDRM6 5 RDRM5 4 RDRM4 3 RDRM3 2 RDRM2 0 0 0 0 0 Figure 2-35. Port M Reduced Drive Register (RDRM) Access: User read/write1 1 0 RDRM1 RDRM0 0 0 Table 2-33. RDRM Register Field Descriptions Field 7-0 RDRM Description Port M reduced drive—Select reduced drive for output pin This bit configures the drive strength of the asscociated output pin as either full or reduced. If a pin is used as input this bit has no effect. The reduced drive function is independent of which function is being used on a particular pin. 1 Reduced drive selected (approx. 1/5 of the full drive strength) 0 Full drive strength enabled 2.3.38 Port M Pull Device Enable Register (PERM) Address 0x0254 R W Reset 7 PERM7 0 1 Read: Anytime Write: Anytime 6 PERM6 5 PERM5 4 PERM4 3 PERM3 2 PERM2 Access: User read/write1 1 0 PERM1 PERM0 0 0 0 0 0 0 0 Figure 2-36. Port M Pull Device Enable Register (PERM) Table 2-34. PERM Register Field Descriptions Field 7-0 PERM Description Port M pull device enable—Enable pull device on input pin or wired-or output pin This bit controls whether a pull device on the associated port input pin is active. If a pin is used as output this bit has only effect if used in wired-or mode. The polarity is selected by the related polarity select register bit. 1 Pull device enabled 0 Pull device disabled S12XS-Family Reference Manual, Rev. 1.03 94 PRELIMINARY Freescale Semiconductor 2.3.39 Port M Polarity Select Register (PPSM) Port Integration Module (S12XSPIMV1) Address 0x0255 R W Reset 7 PPSM7 0 1 Read: Anytime Write: Anytime 6 PPSM6 5 PPSM5 4 PPSM4 3 PPSM3 2 PPSM2 0 0 0 0 0 Figure 2-37. Port M Polarity Select Register (PPSM) Access: User read/write1 1 0 PPSM1 PPSM0 0 0 Table 2-35. PPSM Register Field Descriptions Field 7-0 PPSM Description Port M pull device select—Configure pull device polarity on input pin This bit selects a pull-up or a pull-down device if enabled on the associated port input pin. If CAN0 is active the selection of a pull-down device on the RXCAN input will have no effect. 1 A pull-down device is selected 0 A pull-up device is selected 2.3.40 Port M Wired-Or Mode Register (WOMM) Address 0x0256 R W Reset 7 WOMM7 0 1 Read: Anytime Write: Anytime 6 WOMM6 5 WOMM5 4 WOMM4 3 WOMM3 2 WOMM2 0 0 0 0 0 Figure 2-38. Port M Wired-Or Mode Register (WOMM) Access: User read/write1 1 0 WOMM1 WOMM0 0 0 Table 2-36. WOMM Register Field Descriptions Field Description 7-0 WOMM Port M wired-or mode—Enable open-drain functionality on output pin This bit configures an output pin as wired-or (open-drain) or push-pull. In wired-or mode a logic “0” is driven active low while a logic “1” remains undriven. This allows a multipoint connection of several serial modules. The bit has no influence on pins used as input. 1 Output buffer operates as open-drain output. 0 Output buffer operates as push-pull output. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 95 Port Integration Module (S12XSPIMV1) 2.3.41 Module Routing Register (MODRR) Address 0x0257 7 6 5 4 3 2 R 0 0 0 MODRR7 MODRR6 MODRR4 W Routing Option SCI1 SCI1 — SPI0 — — Reset 0 0 0 0 0 0 = Unimplemented or Reserved 1 Read: Anytime Write: Anytime Figure 2-39. Module Routing Register (MODRR) This register configures the re-routing of SCI1 and SPI0 on alternative ports. Table 2-37. SCI1 Routing MODRRx Related Pins 76 TXD 00 PS3 01 PP2 10 PM1 11 Reserved1 1 Defaults to reset value RXD PS2 PP0 PM0 Reserved1 Table 2-38. SPI0 Routing MODRRx 4 0 1 MISO0 PS4 PM2 Related Pins MOSI0 PS5 PM4 SCK0 PS6 PM5 SS0 PS7 PM3 Access: User read/write1 1 0 0 0 — — 0 0 S12XS-Family Reference Manual, Rev. 1.03 96 PRELIMINARY Freescale Semiconductor 2.3.42 Port P Data Register (PTP) Port Integration Module (S12XSPIMV1) Address 0x0258 7 R PTP7 W 6 PTP6 5 PTP5 4 PTP4 3 PTP3 2 PTP2 Altern. Function PWM7 — PWM6 — PWM5 — PWM4 — PWM3 — PWM2 (IOC2) — — — — — (TXD1) Reset 0 0 0 0 0 0 Figure 2-40. Port P Data Register (PTP) 1 Read: Anytime. The data source is depending on the data direction value. Write: Anytime Access: User read/write1 1 0 PTP1 PTP0 PWM1 (IOC1) — 0 PWM0 (IOC0) (RXD1) 0 Field 7 PTP 6-3 PTP 2 PTP Table 2-39. PTP Register Field Descriptions Description Port P general purpose input/output data—Data Register, PWM input/output, pin interrupt input/output When not used with the alternative function, the associated pin can be used as general purpose I/O. In general purpose output mode the register bit value is driven to the pin. If the associated data direction bit is set to 1, a read returns the value of the port register bit, otherwise the buffered pin input state is read. • The PWM function takes precedence over the general purpose I/O function if the related channel or the emergency shut-down feature is enabled. • Pin interrupts can be generated if enabled in input or output mode. Port P general purpose input/output data—Data Register, PWM output, pin interrupt input/output When not used with the alternative function, the associated pin can be used as general purpose I/O. In general purpose output mode the register bit value is driven to the pin. If the associated data direction bit is set to 1, a read returns the value of the port register bit, otherwise the buffered pin input state is read. • The PWM function takes precedence over the general purpose I/O function if the related channel is enabled. • Pin interrupts can be generated if enabled in input or output mode. Port P general purpose input/output data—Data Register, PWM output, routed TIM output, routed SCI1 TXD output, pin interrupt input/output When not used with the alternative function, the associated pin can be used as general purpose I/O. In general purpose output mode the register bit value is driven to the pin. If the associated data direction bit is set to 1, a read returns the value of the port register bit, otherwise the buffered pin input state is read. • The PWM function takes precedence over the TIM, SCI1 and general purpose I/O function if the related channel is enabled. • The TIM function takes precedence over SCI1 and the general purpose I/O function if the related channel is enabled. • The SCI1 function takes precedence over the general purpose I/O function if enabled. • Pin interrupts can be generated if enabled in input or output mode. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 97 Port Integration Module (S12XSPIMV1) Table 2-39. PTP Register Field Descriptions (continued) Field 1 PTP Description Port P general purpose input/output data—Data Register, PWM output, routed TIM output, pin interrupt input/output When not used with the alternative function, the associated pin can be used as general purpose I/O. In general purpose output mode the register bit value is driven to the pin. If the associated data direction bit is set to 1, a read returns the value of the port register bit, otherwise the buffered pin input state is read. • The PWM function takes precedence over the TIM and general purpose I/O function if the related channel is enabled. • The TIM function takes precedence over the general purpose I/O function if the related channel is enabled. • Pin interrupts can be generated if enabled in input or output mode. 0 Port P general purpose input/output data—Data Register, PWM output, routed TIM output, routed SCI1 RXD PTP output, pin interrupt input/output When not used with the alternative function, the associated pin can be used as general purpose I/O. In general purpose output mode the register bit value is driven to the pin. If the associated data direction bit is set to 1, a read returns the value of the port register bit, otherwise the buffered pin input state is read. • The PWM function takes precedence over the TIM, SCI1 and general purpose I/O function if the related channel is enabled. • The TIM function takes precedence over SCI1 and the general purpose I/O function if the related channel is enabled. • The SCI1 function takes precedence over the general purpose I/O function if enabled. • Pin interrupts can be generated if enabled in input or output mode. 2.3.43 Port P Input Register (PTIP) Address 0x0259 7 R PTIP7 6 PTIP6 5 PTIP5 4 PTIP4 3 PTIP3 2 PTIP2 W Reset u u u u u u = Unimplemented or Reserved u = Unaffected by reset Figure 2-41. Port P Input Register (PTIP) 1 Read: Anytime Write:Never, writes to this register have no effect. Access: User read1 1 PTIP1 0 PTIP0 u u Field 7-0 PTIP Table 2-40. PTIP Register Field Descriptions Description Port P input data— A read always returns the buffered input state of the associated pin. It can be used to detect overload or short circuit conditions on output pins. S12XS-Family Reference Manual, Rev. 1.03 98 PRELIMINARY Freescale Semiconductor 2.3.44 Port P Data Direction Register (DDRP) Port Integration Module (S12XSPIMV1) Address 0x025A R W Reset 7 DDRP7 0 1 Read: Anytime Write: Anytime 6 DDRP6 5 DDRP5 4 DDRP4 3 DDRP3 2 DDRP2 0 0 0 0 0 Figure 2-42. Port P Data Direction Register (DDRP) Access: User read/write1 1 0 DDRP1 DDRP0 0 0 Table 2-41. DDRP Register Field Descriptions Field 7 DDRP Description Port P data direction— This bit determines whether the associated pin is an input or output. The PWM forces the I/O state to be an output for an enabled channel. If the PWM shutdown feature is enabled this pin is forced to be an input. In this case the data direction bit will not change. 6-3 DDRP 1 Associated pin is configured as output 0 Associated pin is configured as input Port P data direction— This bit determines whether the associated pin is an input or output. The PWM forces the I/O state to be an output for an enabled channel. In this case the data direction bit will not change. 2,0 DDRP 1 Associated pin is configured as output 0 Associated pin is configured as input Port P data direction— This bit determines whether the associated pin is an input or output. The PWM forces the I/O state to be an output for an enabled channel. Else the TIM forces the I/O state to be an output for a timer port associated with an enabled output compare. Else depending on the configuration of the enabled SCI the I/O state will be forced to be input or output. In this case the data direction bit will not change. 1 DDRP 1 Associated pin is configured as output 0 Associated pin is configured as input Port P data direction— This bit determines whether the associated pin is an input or output. The PWM forces the I/O state to be an output for an enabled channel. Else the TIM forces the I/O state to be an output for a timer port associated with an enabled output compare. In this case the data direction bit will not change. 1 Associated pin is configured as output 0 Associated pin is configured as input S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 99 Port Integration Module (S12XSPIMV1) 2.3.45 Port P Reduced Drive Register (RDRP) Address 0x025B R W Reset 7 RDRP7 0 1 Read: Anytime Write: Anytime 6 RDRP6 5 RDRP5 4 RDRP4 3 RDRP3 2 RDRP2 0 0 0 0 0 Figure 2-43. Port P Reduced Drive Register (RDRP) Access: User read/write1 1 0 RDRP1 RDRP0 0 0 Table 2-42. RDRP Register Field Descriptions Field 7-0 RDRP Description Port P reduced drive—Select reduced drive for output pin This bit configures the drive strength of the asscociated output pin as either full or reduced. If a pin is used as input this bit has no effect. The reduced drive function is independent of which function is being used on a particular pin. 1 Reduced drive selected (approx. 1/5 of the full drive strength) 0 Full drive strength enabled 2.3.46 Port P Pull Device Enable Register (PERP) Address 0x025C R W Reset 7 PPSP7 0 1 Read: Anytime Write: Anytime 6 PPSP6 5 PPSP5 4 PPSP4 3 PPSP3 2 PPSP2 0 0 0 0 0 Figure 2-44. Port P Pull Device Enable Register (PERP) Access: User read/write1 1 0 PPSP1 PPSP0 0 0 Table 2-43. PERP Register Field Descriptions Field 7-0 PERP Description Port P pull device enable—Enable pull device on input pin This bit controls whether a pull device on the associated port input pin is active. If a pin is used as output this bit has no effect. The polarity is selected by the related polarity select register bit. 1 Pull device enabled 0 Pull device disabled S12XS-Family Reference Manual, Rev. 1.03 100 PRELIMINARY Freescale Semiconductor 2.3.47 Port P Polarity Select Register (PPSP) Port Integration Module (S12XSPIMV1) Address 0x025D R W Reset 7 PPSP7 0 1 Read: Anytime Write: Anytime 6 PPSP6 5 PPSP5 4 PPSP4 3 PPSP3 2 PPSP2 0 0 0 0 0 Figure 2-45. Port P Polarity Select Register (PPSP) Access: User read/write1 1 0 PPSP1 PPSP0 0 0 Table 2-44. PPSP Register Field Descriptions Field 7-0 PPSP Description Port P pull device select—Configure pull device and pin interrupt edge polarity on input pin This bit selects a pull-up or a pull-down device if enabled on the associated port input pin. This bit also selects the polarity of the active pin interrupt edge. 1 A pull-down device is selected; rising edge selected 0 A pull-up device is selected; falling edge selected 2.3.48 Port P Interrupt Enable Register (PIEP) Read: Anytime. Address 0x025E R W Reset 7 PIEP7 0 1 Read: Anytime Write: Anytime 6 PIEP6 5 PIEP5 4 PIEP4 3 PIEP3 2 PIEP2 0 0 0 0 0 Figure 2-46. Port P Interrupt Enable Register (PIEP) Access: User read/write1 1 0 PIEP1 PIEP0 0 0 Field 7-0 PIEP Table 2-45. PPSP Register Field Descriptions Description Port P interrupt enable— This bit enables or disables on the edge sensitive pin interrupt on the associated pin. 1 Interrupt is enabled 0 Interrupt is disabled (interrupt flag masked) S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 101 Port Integration Module (S12XSPIMV1) 2.3.49 Port P Interrupt Flag Register (PIFP) Address 0x025F R W Reset 7 PIFP7 0 1 Read: Anytime Write: Anytime 6 PIFP6 5 PIFP5 4 PIFP4 3 PIFP3 2 PIFP2 0 0 0 0 0 Figure 2-47. Port P Interrupt Flag Register (PIFP) Access: User read/write1 1 0 PIFP1 PIFP0 0 0 Field 7-0 PIFP Table 2-46. PPSP Register Field Descriptions Description Port P interrupt flag— The flag bit is set after an active edge was applied to the associated input pin. This can be a rising or a falling edge based on the state of the polarity select register. Writing a logic “1” to the corresponding bit field clears the flag. 1 Active edge on the associated bit has occurred (an interrupt will occur if the associated enable bit is set) 0 No active edge occured 2.3.50 Port H Data Register (PTH) Address 0x0260 7 R PTH7 W 6 PTH6 5 PTH5 4 PTH4 3 PTH3 2 PTH2 Reset 0 0 0 0 0 0 Figure 2-48. Port H Data Register (PTH) 1 Read: Anytime. The data source is depending on the data direction value. Write: Anytime Access: User read/write1 1 0 PTH1 PTH0 0 0 Field 7-0 PTH Table 2-47. PTH Register Field Descriptions Description Port H general purpose input/output data—Data Register, pin interrupt input/output The associated pin can be used as general purpose I/O. In general purpose output mode the register bit value is driven to the pin. If the associated data direction bit is set to 1, a read returns the value of the port register bit, otherwise the buffered pin input state is read. • Pin interrupts can be generated if enabled in input or output mode. S12XS-Family Reference Manual, Rev. 1.03 102 PRELIMINARY Freescale Semiconductor 2.3.51 Port H Input Register (PTIH) Port Integration Module (S12XSPIMV1) Address 0x0261 7 R PTIH7 6 PTIH6 5 PTIH5 4 PTIH4 3 PTIH3 2 PTIH2 W Reset u u u u u u = Unimplemented or Reserved u = Unaffected by reset Figure 2-49. Port H Input Register (PTIH) 1 Read: Anytime Write:Never, writes to this register have no effect. Access: User read1 1 PTIH1 0 PTIH0 u u Field 7-0 PTIH Table 2-48. PTIH Register Field Descriptions Description Port H input data— A read always returns the buffered input state of the associated pin. It can be used to detect overload or short circuit conditions on output pins. 2.3.52 Port H Data Direction Register (DDRH) Address 0x0262 R W Reset 7 DDRH7 0 1 Read: Anytime Write: Anytime 6 DDRH6 5 DDRH5 4 DDRH4 3 DDRH3 2 DDRH2 0 0 0 0 0 Figure 2-50. Port H Data Direction Register (DDRH) Table 2-49. DDRH Register Field Descriptions Field 7-0 DDRH Description Port H data direction— This bit determines whether the associated pin is an input or output. 1 Associated pin is configured as output 0 Associated pin is configured as input Access: User read/write1 1 0 DDRH1 DDRH0 0 0 S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 103 Port Integration Module (S12XSPIMV1) 2.3.53 Port H Reduced Drive Register (RDRH) Address 0x0263 R W Reset 7 RDRH7 0 1 Read: Anytime Write: Anytime 6 RDRH6 5 RDRH5 4 RDRH4 3 RDRH3 2 RDRH2 0 0 0 0 0 Figure 2-51. Port H Reduced Drive Register (RDRH) Access: User read/write1 1 0 RDRH1 RDRH0 0 0 Table 2-50. RDRH Register Field Descriptions Field 7-0 RDRH Description Port H reduced drive—Select reduced drive for output pin This bit configures the drive strength of the asscociated output pin as either full or reduced. If a pin is used as input this bit has no effect. The reduced drive function is independent of which function is being used on a particular pin. 1 Reduced drive selected (approx. 1/5 of the full drive strength) 0 Full drive strength enabled 2.3.54 Port H Pull Device Enable Register (PERH) Address 0x0264 R W Reset 7 PERH7 0 1 Read: Anytime Write: Anytime 6 PERH6 5 PERH5 4 PERH4 3 PERH3 2 PERH2 0 0 0 0 0 Figure 2-52. Port H Pull Device Enable Register (PERH) Access: User read/write1 1 0 PERH1 PERH0 0 0 Table 2-51. PERH Register Field Descriptions Field 7-0 PERH Description Port H pull device enable—Enable pull device on input pin This bit controls whether a pull device on the associated port input pin is active. If a pin is used as output this bit has no effect. The polarity is selected by the related polarity select register bit. 1 Pull device enabled 0 Pull device disabled S12XS-Family Reference Manual, Rev. 1.03 104 PRELIMINARY Freescale Semiconductor 2.3.55 Port H Polarity Select Register (PPSH) Port Integration Module (S12XSPIMV1) Address 0x025D R W Reset 7 PPSH7 0 1 Read: Anytime Write: Anytime 6 PPSH6 5 PPSH5 4 PPSH4 3 PPSH3 2 PPSH2 0 0 0 0 0 Figure 2-53. Port H Polarity Select Register (PPSH) Access: User read/write1 1 0 PPSH1 PPSH0 0 0 Table 2-52. PPSH Register Field Descriptions Field 7-0 PPSH Description Port H pull device select—Configure pull device and pin interrupt edge polarity on input pin This bit selects a pull-up or a pull-down device if enabled on the associated port input pin. This bit also selects the polarity of the active pin interrupt edge. 1 A pull-down device is selected; rising edge selected 0 A pull-up device is selected; falling edge selected 2.3.56 Port H Interrupt Enable Register (PIEH) Read: Anytime. Address 0x025E R W Reset 7 PIEH7 0 1 Read: Anytime Write: Anytime 6 PIEH6 5 PIEH5 4 PIEH4 3 PIEH3 2 PIEH2 0 0 0 0 0 Figure 2-54. Port H Interrupt Enable Register (PIEH) Access: User read/write1 1 0 PIEH1 PIEH0 0 0 Field 7-0 PIEH Table 2-53. PPSP Register Field Descriptions Description Port H interrupt enable— This bit enables or disables on the edge sensitive pin interrupt on the associated pin. 1 Interrupt is enabled 0 Interrupt is disabled (interrupt flag masked) S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 105 Port Integration Module (S12XSPIMV1) 2.3.57 Port H Interrupt Flag Register (PIFH) Address 0x025F R W Reset 7 PIFH7 0 1 Read: Anytime Write: Anytime 6 PIFH6 5 PIFH5 4 PIFH4 3 PIFH3 2 PIFH2 0 0 0 0 0 Figure 2-55. Port H Interrupt Flag Register (PIFH) Access: User read/write1 1 0 PIFH1 PIFH0 0 0 Field 7-0 PIFH Table 2-54. PPSP Register Field Descriptions Description Port H interrupt flag— The flag bit is set after an active edge was applied to the associated input pin. This can be a rising or a falling edge based on the state of the polarity select register. Writing a logic “1” to the corresponding bit field clears the flag. 1 Active edge on the associated bit has occurred (an interrupt will occur if the associated enable bit is set) 0 No active edge occured 2.3.58 Port J Data Register (PTJ) Address 0x0268 7 6 5 4 3 2 R 0 0 0 0 PTJ7 PTJ6 W Reset 0 0 0 0 0 0 Figure 2-56. Port J Data Register (PTJ) 1 Read: Anytime. The data source is depending on the data direction value. Write: Anytime Access: User read/write1 1 0 PTJ1 PTJ0 0 0 Table 2-55. PTJ Register Field Descriptions Field Description 7-6, 1-0 PTJ Port J general purpose input/output data—Data Register, pin interrupt input/output The associated pin can be used as general purpose I/O. In general purpose output mode the register bit value is driven to the pin. If the associated data direction bit is set to 1, a read returns the value of the port register bit, otherwise the buffered pin input state is read. • Pin interrupts can be generated if enabled in input or output mode. S12XS-Family Reference Manual, Rev. 1.03 106 PRELIMINARY Freescale Semiconductor 2.3.59 Port J Input Register (PTIJ) Port Integration Module (S12XSPIMV1) Address 0x0269 7 6 5 4 3 2 R PTIJ7 PTIJ6 0 0 0 0 W Reset u u u u u u = Unimplemented or Reserved u = Unaffected by reset Figure 2-57. Port J Input Register (PTIJ) 1 Read: Anytime Write:Never, writes to this register have no effect. Access: User read1 1 PTIJ1 0 PTIJ0 u u Table 2-56. PTIJ Register Field Descriptions Field Description 7-6, 1-0 PTIJ Port J input data— A read always returns the buffered input state of the associated pin. It can be used to detect overload or short circuit conditions on output pins. 2.3.60 Port J Data Direction Register (DDRJ) Address 0x026A R W Reset 7 DDRJ7 0 1 Read: Anytime Write: Anytime 6 5 4 3 2 0 0 0 0 DDRJ6 0 0 0 0 0 Figure 2-58. Port J Data Direction Register (DDRJ) Table 2-57. DDRJ Register Field Descriptions Field Description 7-6, 1-0 Port J data direction— DDRJ This bit determines whether the associated pin is an input or output. 1 Associated pin is configured as output 0 Associated pin is configured as input Access: User read/write1 1 0 DDRJ1 DDRJ0 0 0 S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 107 Port Integration Module (S12XSPIMV1) 2.3.61 Port J Reduced Drive Register (RDRJ) Address 0x026B R W Reset 7 RDRJ7 0 1 Read: Anytime Write: Anytime 6 5 4 3 2 0 0 0 0 RDRJ6 0 0 0 0 0 Figure 2-59. Port J Reduced Drive Register (RDRJ) Access: User read/write1 1 0 RDRJ1 RDRJ0 0 0 Table 2-58. RDRJ Register Field Descriptions Field Description 7-6, 1-0 RDRJ Port J reduced drive—Select reduced drive for outputs This register configures the drive strength as either full or reduced. If a pin is used as input this bit has no effect. 1 Reduced drive selected (approx. 1/5 of the full drive strength). 0 Full drive strength enabled. 2.3.62 Port J Pull Device Enable Register (PERJ) Address 0x026C R W Reset 7 PERJ7 1 1 Read: Anytime Write: Anytime 6 5 4 3 2 0 0 0 0 PERJ6 1 1 1 1 1 Figure 2-60. Port J Pull Device Enable Register (PERJ) Access: User read/write1 1 0 PERJ1 PERJ0 1 1 Table 2-59. PERJ Register Field Descriptions Field Description 7-6, 1-0 PERJ Port J pull device enable—Select reduced drive for output pin This bit configures the drive strength of the asscociated output pin as either full or reduced. If a pin is used as input this bit has no effect. The reduced drive function is independent of which function is being used on a particular pin. 1 Reduced drive selected (approx. 1/5 of the full drive strength) 0 Full drive strength enabled S12XS-Family Reference Manual, Rev. 1.03 108 PRELIMINARY Freescale Semiconductor 2.3.63 Port J Polarity Select Register (PPSJ) Port Integration Module (S12XSPIMV1) Address 0x026D R W Reset 7 PPSJ7 0 1 Read: Anytime Write: Anytime 6 5 4 3 2 0 0 0 0 PPSJ6 0 0 0 0 0 Figure 2-61. Port J Polarity Select Register (PPSJ) Access: User read/write1 1 0 PPSJ1 PPSJ0 0 0 Table 2-60. PPSJ Register Field Descriptions Field Description 7-6, 1-0 PPSJ Port J pull device select—Configure pull device and pin interrupt edge polarity on input pin This bit selects a pull-up or a pull-down device if enabled on the associated port input pin. This bit also selects the polarity of the active pin interrupt edge. 1 A pull-down device is selected; rising edge selected 0 A pull-up device is selected; falling edge selected 2.3.64 Port J Interrupt Enable Register (PIEJ) Read: Anytime. Address 0x026E R W Reset 7 PIEJ7 0 1 Read: Anytime Write: Anytime 6 5 4 3 2 0 0 0 0 PIEJ6 0 0 0 0 0 Figure 2-62. Port J Interrupt Enable Register (PIEJ) Access: User read/write1 1 0 PIEJ1 PIEJ0 0 0 Table 2-61. PPSP Register Field Descriptions Field Description 7-6, 1-0 Port J interrupt enable— PIEJ This bit enables or disables on the edge sensitive pin interrupt on the associated pin. 1 Interrupt is enabled 0 Interrupt is disabled (interrupt flag masked) S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 109 Port Integration Module (S12XSPIMV1) 2.3.65 Port J Interrupt Flag Register (PIFJ) Address 0x026F R W Reset 7 PIFJ7 0 1 Read: Anytime Write: Anytime 6 5 4 3 2 0 0 0 0 PIFJ6 0 0 0 0 0 Figure 2-63. Port J Interrupt Flag Register (PIFJ) Access: User read/write1 1 0 PIFJ1 PIFJ0 0 0 Table 2-62. PPSP Register Field Descriptions Field Description 7-6, 1-0 PIFJ Port J interrupt flag— The flag bit is set after an active edge was applied to the associated input pin. This can be a rising or a falling edge based on the state of the polarity select register. Writing a logic “1” to the corresponding bit field clears the flag. 1 Active edge on the associated bit has occurred (an interrupt will occur if the associated enable bit is set) 0 No active edge occured 2.3.66 Port AD0 Data Register 0 (PT0AD0) Address 0x0270 7 R PT0AD07 W 6 PT0AD06 5 PT0AD05 4 PT0AD04 3 PT0AD03 2 PT0AD02 Altern. Function AN15 AN14 AN13 AN12 AN11 AN10 Reset 0 0 0 0 0 0 Figure 2-64. Port AD0 Data Register 0 (PT0AD0) 1 Read: Anytime. The data source is depending on the data direction value. Write: Anytime Access: User read/write1 1 0 PT0AD01 PT0AD00 AN9 AN8 0 0 Table 2-63. PT0AD0 Register Field Descriptions Field Description 7-0 PT0AD0 Port AD0 general purpose input/output data—Data Register, ATD AN analog input When not used with the alternative function, the associated pin can be used as general purpose I/O. In general purpose output mode the register bit value is driven to the pin. If the associated data direction bit is set to 1, a read returns the value of the port register bit, otherwise the buffered pin input state is read. S12XS-Family Reference Manual, Rev. 1.03 110 PRELIMINARY Freescale Semiconductor 2.3.67 Port AD0 Data Register 1 (PT1AD0) Port Integration Module (S12XSPIMV1) Address 0x0271 7 R PT1AD07 W 6 PT1AD06 5 PT1AD05 4 PT1AD04 3 PT1AD03 2 PT1AD02 Altern. Function AN7 AN6 AN5 AN4 AN3 AN2 Reset 0 0 0 0 0 0 Figure 2-65. Port AD0 Data Register 1 (PT1AD0) 1 Read: Anytime. The data source is depending on the data direction value. Write: Anytime Access: User read/write1 1 0 PT1AD01 PT1AD00 AN1 AN0 0 0 Table 2-64. PT1AD0 Register Field Descriptions Field Description 7-0 PT1AD0 Port AD0 general purpose input/output data—Data Register, ATD AN analog input When not used with the alternative function, the associated pin can be used as general purpose I/O. In general purpose output mode the register bit value is driven to the pin. If the associated data direction bit is set to 1, a read returns the value of the port register bit, otherwise the buffered pin input state is read. 2.3.68 Port AD0 Data Direction Register 0 (DDR0AD0) Address 0x0272 Access: User read/write1 7 R DDR0AD07 W 6 DDR0AD06 5 DDR0AD05 4 DDR0AD04 3 DDR0AD03 2 DDR0AD02 1 DDR0AD01 0 DDR0AD00 Reset 0 0 0 0 0 0 0 0 1 Read: Anytime Write: Anytime Figure 2-66. Port AD0 Data Direction Register 0 (DDR0AD0) Table 2-65. DDR0AD0 Register Field Descriptions Field Description 7-0 Port AD0 data direction— DDR0AD0 This bit determines whether the associated pin is an input or output. To use the digital input function the ATD Digital Input Enable Register (ATD0DIEN) has to be set to logic level “1”. 1 Associated pin is configured as output 0 Associated pin is configured as input S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 111 Port Integration Module (S12XSPIMV1) 2.3.69 Port AD0 Data Direction Register 1 (DDR1AD0) Address 0x0273 Access: User read/write1 7 R DDR1AD07 W 6 DDR1AD06 5 DDR1AD05 4 DDR1AD04 3 DDR1AD03 2 DDR1AD02 1 DDR1AD01 0 DDR1AD00 Reset 0 0 0 0 0 0 0 0 1 Read: Anytime Write: Anytime Figure 2-67. Port AD0 Data Direction Register 1 (DDR1AD0) Table 2-66. DDR1AD0 Register Field Descriptions Field Description 7-0 Port AD0 data direction— DDR1AD0 This bit determines whether the associated pin is an input or output. To use the digital input function the ATD Digital Input Enable Register (ATD0DIEN) has to be set to logic level “1”. 1 Associated pin is configured as output 0 Associated pin is configured as input 2.3.70 Port AD0 Reduced Drive Register 0 (RDR0AD0) Address 0x0274 Access: User read/write1 7 R RDR0AD07 W 6 RDR0AD06 5 RDR0AD05 4 RDR0AD04 3 RDR0AD03 2 RDR0AD02 1 RDR0AD01 0 RDR0AD00 Reset 0 0 0 0 0 0 0 0 1 Read: Anytime Write: Anytime Figure 2-68. Port AD0 Reduced Drive Register 0 (RDR0AD0) Table 2-67. RDR0AD0 Register Field Descriptions Field Description 7-0 Port AD0 reduced drive—Select reduced drive for output pin RDR0AD0 This bit configures the drive strength of the asscociated output pin as either full or reduced. If a pin is used as input this bit has no effect. The reduced drive function is independent of which function is being used on a particular pin. 1 Reduced drive selected (approx. 1/5 of the full drive strength) 0 Full drive strength enabled S12XS-Family Reference Manual, Rev. 1.03 112 PRELIMINARY Freescale Semiconductor 2.3.71 Port Integration Module (S12XSPIMV1) Port AD0 Reduced Drive Register 1 (RDR1AD0) Address 0x0275 Access: User read/write1 7 R RDR1AD07 W 6 RDR1AD06 5 RDR1AD05 4 RDR1AD04 3 RDR1AD03 2 RDR1AD02 1 RDR1AD01 0 RDR1AD00 Reset 0 0 0 0 0 0 0 0 1 Read: Anytime Write: Anytime Figure 2-69. Port AD0 Reduced Drive Register 1 (RDR1AD0) Table 2-68. RDR1AD0 Register Field Descriptions Field Description 7-0 Port AD0 reduced drive—Select reduced drive for output pin RDR1AD0 This bit configures the drive strength of the asscociated output pin as either full or reduced. If a pin is used as input this bit has no effect. The reduced drive function is independent of which function is being used on a particular pin. 1 Reduced drive selected (approx. 1/5 of the full drive strength) 0 Full drive strength enabled 2.3.72 Port AD0 Pull Up Enable Register 0 (PER0AD0) Address 0x0276 Access: User read/write1 7 R PER0AD07 W 6 PER0AD06 5 PER0AD05 4 PER0AD04 3 PER0AD03 2 PER0AD02 1 PER0AD01 0 PER0AD00 Reset 0 0 0 0 0 0 0 0 1 Read: Anytime Write: Anytime Figure 2-70. Port AD0 Pull Device Up Register 0 (PER0AD0) Table 2-69. PER0AD0 Register Field Descriptions Field Description 7-0 Port AD0 pull device enable—Enable pull-up device on input pin PER0AD0 This bit controls whether a pull device on the associated port input pin is active. If a pin is used as output this bit has no effect. The polarity is selected by the related polarity select register bit. 1 Pull device enabled 0 Pull device disabled S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 113 Port Integration Module (S12XSPIMV1) 2.3.73 Port AD0 Pull Up Enable Register 1 (PER1AD0) Address 0x0277 Access: User read/write1 7 R PER1AD07 W 6 PER1AD06 5 PER1AD05 4 PER1AD04 3 PER1AD03 2 PER1AD02 1 PER1AD01 0 PER1AD00 Reset 0 0 0 0 0 0 0 0 1 Read: Anytime Write: Anytime Figure 2-71. Port AD0 Pull Up Enable Register 1 (PER1AD0) Table 2-70. PER1AD0 Register Field Descriptions Field Description 7-0 Port AD0 pull device enable—Enable pull-up device on input pin PER1AD0 This bit controls whether a pull device on the associated port input pin is active. If a pin is used as output this bit has no effect. The polarity is selected by the related polarity select register bit. 1 Pull device enabled 0 Pull device disabled 2.3.74 PIM Reserved Registers Address 0x0278-0x27F 7 6 5 4 3 2 R 0 0 0 0 0 0 W Reset 0 0 0 0 0 0 = Unimplemented or Reserved u = Unaffected by reset 1 Read: Always reads 0x00 Write: Unimplemented Figure 2-72. PIM Reserved Registers 2.4 Functional Description Access: User read1 1 0 0 0 0 0 2.4.1 General Each pin except PE0, PE1, and BKGD can act as general purpose I/O. In addition each pin can act as an output or input of a peripheral module. 2.4.2 Registers A set of configuration registers is common to all ports with exception of the ATD port (Table 2-71). All registers can be written at any time, however a specific configuration might not become active. S12XS-Family Reference Manual, Rev. 1.03 114 PRELIMINARY Freescale Semiconductor Port Integration Module (S12XSPIMV1) For example selecting a pull-up device: This device does not become active while the port is used as a push-pull output. Table 2-71. Register availability per port1 Port Data Input Data Reduced Pull Direction Drive Enable Polarity Select A yes - yes yes yes - B yes - yes - E yes - yes - K yes - yes - T yes yes yes yes yes yes S yes yes yes yes yes yes M yes yes yes yes yes yes P yes yes yes yes yes yes H yes yes yes yes yes yes J yes yes yes yes yes yes AD yes - yes yes yes - 1 Each cell represents one register with individual configuration bits Wired- Interrupt Interrupt Or Mode Enable Flag - - - - - - - - - - - - - - - yes - - yes - - - yes yes - yes yes - yes yes - - - Routing yes yes - 2.4.2.1 Data register (PORTx, PTx) This register holds the value driven out to the pin if the pin is used as a general purpose I/O. Writing to this register has only an effect on the pin if the pin is used as general purpose output. When reading this address, the buffered state of the pin is returned if the associated data direction register bit is set to “0”. If the data direction register bits are set to logic level “1”, the contents of the data register is returned. This is independent of any other configuration (Figure 2-73). 2.4.2.2 Input register (PTIx) This is a read-only register and always returns the buffered state of the pin (Figure 2-73). 2.4.2.3 Data direction register (DDRx) This register defines whether the pin is used as an input or an output. If a peripheral module controls the pin the contents of the data direction register is ignored (Figure 2-73). Independent of the pin usage with a peripheral module this register determines the source of data when reading the associated data register address (2.4.2.1/2-115). NOTE Due to internal synchronization circuits, it can take up to 2 bus clock cycles until the correct value is read on port data or port input registers, when changing the data direction register. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 115 Port Integration Module (S12XSPIMV1) PTI 0 1 PT 0 1 PIN DDR 0 1 data out Module output enable module enable Figure 2-73. Illustration of I/O pin functionality 2.4.2.4 Reduced drive register (RDRx) If the pin is used as an output this register allows the configuration of the drive strength independent of the use with a peripheral module. 2.4.2.5 Pull device enable register (PERx) This register turns on a pull-up or pull-down device on the related pins determined by the associatedpolarity select register (2.4.2.5/2-116). The pull device becomes active only if the pin is used as an input or as a wired-or output. Some peripheral module only allow certain configurations of pull devices to become active. Refer to the respective bit descriptions. 2.4.2.6 Polarity select register (PPSx) This register selects either a pull-up or pull-down device if enabled. It becomes only active if the pin is used as an input. A pull-up device can be activated if the pin is used as a wired-or output. 2.4.2.7 Wired-or mode register (WOMx) If the pin is used as an output this register turns off the active high drive. This allows wired-or type connections of outputs. S12XS-Family Reference Manual, Rev. 1.03 116 PRELIMINARY Freescale Semiconductor Port Integration Module (S12XSPIMV1) 2.4.2.8 Interrupt enable register (PIEx) If the pin is used as an interrupt input this register serves as a mask to the interrupt flag to enable/disable the interrupt. 2.4.2.9 Interrupt flag register (PIFx) If the pin is used as an interrupt input this register holds the interrupt flag after a valid pin event. 2.4.2.10 Module routing registers (MODRR, PTTRR) These registers allow software re-configuration of the pinouts of the different package options for specific peripherals: • MODRR supports the re-routing of the SCI1 and SPI0 pins to alternative ports • PTTRR supports the re-routing of the PWM and TIM channels to alternative ports 2.4.3 Pins and Ports NOTE Please refer to the device pinout section to determine the pin availability in the different package options. 2.4.3.1 BKGD pin The BKGD pin is associated with the BDM module. During reset, the BKGD pin is used as MODC input. 2.4.3.2 Port A, B Port A pins PA[7:0] and Port B pins PB[7:0] can be used for general-purpose I/O. 2.4.3.3 Port E Port E is associated with the free-running clock outputs ECLK, ECLKX2 and interrupt inputs IRQ and XIRQ. Port E pins PE[7:2] can be used for either general-purpose I/O or with the alternative functions. Port E pin PE[7] an be used for either general-purpose I/O or as the free-running clock ECLKX2 output running at the core clock rate. Port E pin PE[4] an be used for either general-purpose I/O or as the free-running clock ECLK output running at the bus clock rate or at the programmed divided clock rate. Port E pin PE[1] can be used for either general-purpose input or as the level- or falling edge-sensitive IRQ interrupt input. IRQ will be enabled by setting the IRQEN configuration bit (2.3.14/2-78) and clearing the I-bit in the CPU condition code register. It is inhibited at reset so this pin is initially configured as a simple input with a pull-up. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 117 Port Integration Module (S12XSPIMV1) Port E pin PE[0] can be used for either general-purpose input or as the level-sensitive XIRQ interrupt input. XIRQ can be enabled by clearing the X-bit in the CPU condition code register. It is inhibited at reset so this pin is initially configured as a high-impedance input with a pull-up. 2.4.3.4 Port K Port K pins PK[7,5:0] can be used for general-purpose I/O. 2.4.3.5 Port T This port is associated with TIM and PWM. Port T pins PT[7:4] can be used for either general-purpose I/O, or with the PWM or with the channels of the standard Timer subsystem. Port T pins PT[3:0] can be used for either general-purpose I/O, or with the channels of the standard Timer subsystem. The TIM pins IOC2-0 can be re-routed. 2.4.3.6 Port S This port is associated with SPI0, SCI0 and SCI1. Port S pins PS[7:4] can be used either for general-purpose I/O, or with the SPI0 subsystem. Port S pins PS[3:2] can be used either for general-purpose I/O, or with the SCI1 subsystem. Port S pins PS[1:0] can be used either for general-purpose I/O, or with the SCI0 subsystem. The SPI0 and SCI1 pins can be re-routed. 2.4.3.7 Port M This port is associated with CAN0 and SCI1. Port M pins PM[7:6] can be used for either general purpose I/O. Port M pins PM[1:0] can be used for either general purpose I/O, or with the CAN0 or with the SCI1 subsystem. Port M pins PM[5:2] can be used for general purpose I/O. 2.4.3.8 Port P This port is associated with the PWM, TIM and SCI1. Port P pins PP[7:3] can be used for either general purpose I/O with pin interrupt capability, or with the PWM or with the channels of the standard Timer.subsystem. Port P pins PP[2,0] can be used for either general purpose I/O, or with the PWM or with the TIM or with the SCI1 subsystem. S12XS-Family Reference Manual, Rev. 1.03 118 PRELIMINARY Freescale Semiconductor Port Integration Module (S12XSPIMV1) Port P pin PP[1] can be used for either general purpose I/O, or with the PWM or with the TIM subsystem. 2.4.3.9 Port H Port H pins PH[7:0] can be used for general purpose I/O with pin interrupt capability. 2.4.3.10 Port J Port J pins PJ[7,6,1,0] can be used for general purpose I/O with pin-interrupt capability. 2.4.3.11 Port AD This port is associated with the ATD. Port AD pins PAD[15:0] can be used for either general purpose I/O, or with the ATD0 subsystem. 2.4.4 Pin interrupts Ports P, H and J offer pin interrupt capability. The interrupt enable as well as the sensitivity to rising or falling edges can be individually configured on per-pin basis. All bits/pins in a port share the same interrupt vector. Interrupts can be used with the pins configured as inputs or outputs. An interrupt is generated when a bit in the port interrupt flag register and its corresponding port interrupt enable bit are both set. The pin interrupt feature is also capable to wake up the CPU when it is in STOP or WAIT mode. A digital filter on each pin prevents pulses (Figure 2-75) shorter than a specified time from generating an interrupt. The minimum time varies over process conditions, temperature and voltage (Figure 2-74 and Table 2-72). Glitch, filtered out, no interrupt flag set Valid pulse, interrupt flag set uncertain tpign tpval Figure 2-74. Interrupt Glitch Filter on Port P, H and J (PPS=0) S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 119 Port Integration Module (S12XSPIMV1) Table 2-72. Pulse Detection Criteria Mode Pulse STOP STOP1 Unit Ignored tpulse ≤ 3 bus clocks tpulse ≤ tpign Uncertain 3 < tpulse < 4 bus clocks tpign < tpulse < tpval Valid tpulse ≥ 4 bus clocks tpulse ≥ tpval 1These values include the spread of the oscillator frequency over temperature, voltage and process. tpulse Figure 2-75. Pulse Illustration A valid edge on an input is detected if 4 consecutive samples of a passive level are followed by 4 consecutive samples of an active level directly or indirectly. The filters are continuously clocked by the bus clock in RUN and WAIT mode. In STOP mode the clock is generated by an RC-oscillator in the Port Integration Module. To maximize current saving the RC oscillator runs only if the following condition is true on any pin individually: Sample count <= 4 and interrupt enabled (PIE=1) and interrupt flag not set (PIF=0). 2.5 Initialization Information 2.5.1 Port Data and Data Direction Register writes It is not recommended to write PORTx/PTx and DDRx in a word access. When changing the register pins from inputs to outputs, the data may have extra transitions during the write access. Initialize the port data register before enabling the outputs. S12XS-Family Reference Manual, Rev. 1.03 120 PRELIMINARY Freescale Semiconductor Chapter 3 Memory Mapping Control (S12XMMCV4) Revision History Rev. No. (Item No.) v04.07 Date (Submitted By) 02-Apr-07 v04.08 04-May-07 v04.09 01-Feb-08 Sections Affected Substantial Change(s) - Adapting the MMC context to support S12XS family - Clarifying RPAGE usage for less than 12KB RAMSIZE. - Some Cleanups - Minor changes 3.1 Introduction This section describes the functionality of the module mapping control (MMC) sub-block of the S12X platform. The block diagram of the MMC is shown in Figure 3-1. The MMC module controls the multi-master priority accesses, the selection of internal resources . Internal buses, including internal memories and peripherals, are controlled in this module. The local address space for each master is translated to a global memory space. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 121 Memory Mapping Control (S12XMMCV4) 3.1.1 Terminology Table 3-1. Acronyms and Abbreviations Logic level “1” Logic level “0” 0x x Byte word local address global address Aligned address Mis-aligned address Bus Clock single-chip modes normal modes Voltage that corresponds to Boolean true state Voltage that corresponds to Boolean false state Represents hexadecimal number Represents logic level ’don’t care’ 8-bit data 16-bit data based on the 64KB Memory Space (16-bit address) based on the 8MB Memory Space (23-bit address) Address on even boundary Address on odd boundary System Clock. Refer to CRG Block Guide. Normal Single-Chip Mode Special Single-Chip Mode Normal Single-Chip Mode special modes Special Single-Chip Mode NS SS Unimplemented areas PRR PRU MCU NVM IFR Normal Single-Chip Mode Special Single-Chip Mode Areas which are accessible by the pages (RPAGE,PPAGE,EPAGE) and not implemented Port Replacement Registers Port Replacement Unit located on the emulator side MicroController Unit Non-volatile Memory; Flash, Data FLASH or ROM Information Row sector located on the top of NVM. For Test purposes. 3.1.2 Features The main features of this block are: • Paging capability to support a global 8MB memory address space • Bus arbitration between the masters CPU, BDM • Simultaneous accesses to different resources1 (internal, and peripherals) (see Figure 3-1 ) • Resolution of target bus access collision • MCU operation mode control • MCU security control • Separate memory map schemes for each master CPU, BDM • ROM control bits to enable the on-chip FLASH or ROM selection • Generation of system reset when CPU accesses an unimplemented address (i.e., an address which does not belong to any of the on-chip modules) in single-chip modes 1. Resources are also called targets. S12XS-Family Reference Manual, Rev. 1.03 122 PRELIMINARY Freescale Semiconductor Memory Mapping Control (S12XMMCV4) 3.1.3 S12X Memory Mapping The S12X architecture implements a number of memory mapping schemes including • a CPU 8MB global map, defined using a global page (GPAGE) register and dedicated 23-bit address load/store instructions. • a BDM 8MB global map, defined using a global page (BDMGPR) register and dedicated 23-bit address load/store instructions. • a (CPU or BDM) 64KB local map, defined using specific resource page (RPAGE, EPAGE and PPAGE) registers and the default instruction set. The 64KB visible at any instant can be considered as the local map accessed by the 16-bit (CPU or BDM) address. The MMC module performs translation of the different memory mapping schemes to the specific global (physical) memory implementation. 3.1.4 Modes of Operation This subsection lists and briefly describes all operating modes supported by the MMC. 3.1.4.1 Power Saving Modes • Run mode MMC is functional during normal run mode. • Wait mode MMC is functional during wait mode. • Stop mode MMC is inactive during stop mode. 3.1.4.2 Functional Modes • Single chip modes In normal and special single chip mode the internal memory is used. 3.1.5 Block Diagram Figure 3-1 shows a block diagram of the MMC. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 123 Memory Mapping Control (S12XMMCV4) BDM MMC Address Decoder & Priority CPU Target Bus Controller DBG Data FLASH PGMFLASH RAM Peripherals Figure 3-1. MMC Block Diagram 3.2 External Signal Description The user is advised to refer to the SoC Guide for port configuration and location of external bus signals. Some pins may not be bonded out in all implementations. Table 3-2 outlines the pin names and functions. It also provides a brief description of their operation. Table 3-2. External Input Signals Associated with the MMC Signal I/O MODC I Description Mode input Availability Latched after RESET (active low) S12XS-Family Reference Manual, Rev. 1.03 124 PRELIMINARY Freescale Semiconductor 3.3 Memory Map and Registers Memory Mapping Control (S12XMMCV4) 3.3.1 Module Memory Map A summary of the registers associated with the MMC block is shown in Figure 3-2. Detailed descriptions of the registers and bits are given in the subsections that follow. Address Register Name Bit 7 6 5 4 3 2 1 Bit 0 0x000A Reserved R 0 0 0 0 0 0 0 0 W 0x000B MODE R 0 0 0 0 0 0 0 MODC W 0x0010 GPAGE R 0 W GP6 GP5 GP4 GP3 GP2 GP1 GP0 0x0011 DIRECT R W DP15 DP14 DP13 DP12 DP11 DP10 DP9 DP8 0x0012 Reserved R 0 W 0 0 0 0 0 0 0 0x0013 MMCCTL1 R 0 0 0 0 0 MGRAMON DFIFRON PGMIFRON W 0x0014 Reserved R 0 W 0 0 0 0 0 0 0 0x0015 PPAGE R W PIX7 PIX6 PIX5 PIX4 PIX3 PIX2 PIX1 PIX0 0x0016 RPAGE R RP7 W RP6 RP5 RP4 RP3 RP2 RP1 RP0 0x0017 EPAGE R EP7 W EP6 EP5 EP4 EP3 EP2 EP1 EP0 = Unimplemented or Reserved Figure 3-2. MMC Register Summary 3.3.2 Register Descriptions S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 125 Memory Mapping Control (S12XMMCV4) 3.3.2.1 Mode Register (MODE) Address: 0x000B PRR 7 6 5 4 3 2 1 0 R 0 0 0 0 0 0 0 MODC W Reset MODC1 0 0 0 0 0 0 0 1. External signal (see Table 3-2). = Unimplemented or Reserved Figure 3-3. Mode Register (MODE) Read: Anytime. Write: Only if a transition is allowed (see Figure 3-5). The MODE bits of the MODE register are used to establish the MCU operating mode. Field 7 MODC Table 3-3. MODE Field Descriptions Description Mode Select Bit — This bit controls the current operating mode during RESET high (inactive). The external mode pin MODC determines the operating mode during RESET low (active). The state of the pin is latched into the respective register bit after the RESET signal goes inactive (see Figure 3-3). Write restrictions exist to disallow transitions between certain modes. Figure 3-5 illustrates all allowed mode changes. Attempting non authorized transitions will not change the MODE bits, but it will block further writes to these register bits except in special modes. Write accesses to the MODE register are blocked when the device is secured. Figure 3-4. Normal 1 RESET Single-Chip 1 (NS) 1 Transition done by external pins (MODC) RESET State Transition done by write access to the MODE register State State Special Single-Chip (SS) 0 0 RESET Figure 3-5. Mode Transition Diagram when MCU is Unsecured S12XS-Family Reference Manual, Rev. 1.03 126 PRELIMINARY Freescale Semiconductor Memory Mapping Control (S12XMMCV4) 3.3.2.2 Global Page Index Register (GPAGE) Address: 0x0010 7 R 0 W 6 GP6 5 GP5 4 GP4 Reset 0 0 0 0 = Unimplemented or Reserved 3 GP3 0 2 GP2 0 1 GP1 0 0 GP0 0 Figure 3-6. Global Page Index Register (GPAGE) Read: Anytime Write: Anytime The global page index register is used to construct a 23 bit address in the global map format. It is only used when the CPU is executing a global instruction (GLDAA, GLDAB, GLDD, GLDS, GLDX, GLDY,GSTAA, GSTAB, GSTD, GSTS, GSTX, GSTY) (see CPU Block Guide). The generated global address is the result of concatenation of the CPU local address [15:0] with the GPAGE register [22:16] (see Figure 3-7). Bit22 Global Address [22:0] Bit16 Bit15 Bit 0 GPAGE Register [6:0] CPU Address [15:0] Figure 3-7. GPAGE Address Mapping Table 3-4. GPAGE Field Descriptions Field 6–0 GP[6:0] Description Global Page Index Bits 6–0 — These page index bits are used to select which of the 128 64KB pages is to be accessed. Example 3-1. This example demonstrates usage of the GPAGE register LDX MOVB GLDAA #0x5000 #0x14, GPAGE X ;Set GPAGE offset to the value of 0x5000 ;Initialize GPAGE register with the value of 0x14 ;Load Accu A from the global address 0x14_5000 S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 127 Memory Mapping Control (S12XMMCV4) 3.3.2.3 Direct Page Register (DIRECT) Address: 0x0011 R W Reset 7 DP15 0 6 DP14 0 5 DP13 0 4 DP12 0 3 DP11 0 2 DP10 0 1 DP9 0 0 DP8 0 Figure 3-8. Direct Register (DIRECT) Read: Anytime Write: anytime in special modes, one time only in other modes. This register determines the position of the 256B direct page within the memory map.It is valid for both global and local mapping scheme. Table 3-5. DIRECT Field Descriptions Field 7–0 DP[15:8] Description Direct Page Index Bits 15–8 — These bits are used by the CPU when performing accesses using the direct addressing mode. The bits from this register form bits [15:8] of the address (see Figure 3-9). Global Address [22:0] Bit22 Bit16 Bit15 Bit8 Bit7 Bit0 DP [15:8] CPU Address [15:0] Figure 3-9. DIRECT Address Mapping Bits [22:16] of the global address will be formed by the GPAGE[6:0] bits in case the CPU executes a global instruction in direct addressing mode or by the appropriate local address to the global address expansion (refer to Section 3.4.2.1.1, “Expansion of the Local Address Map). Example 3-2. This example demonstrates usage of the Direct Addressing Mode MOVB #0x80,DIRECT ;Set DIRECT register to 0x80. Write once only. ;Global data accesses to the range 0xXX_80XX can be direct. ;Logical data accesses to the range 0x80XX are direct. LDY <00 ;Load the Y index register from 0x8000 (direct access). ;< operator forces direct access on some assemblers but in ;many cases assemblers are “direct page aware” and can ;automatically select direct mode. S12XS-Family Reference Manual, Rev. 1.03 128 PRELIMINARY Freescale Semiconductor Memory Mapping Control (S12XMMCV4) 3.3.2.4 MMC Control Register (MMCCTL1) Address: 0x0013 PRR 7 6 5 4 3 2 1 0 R 0 0 0 0 0 MGRAMON DFIFRON PGMIFRON W Reset 0 0 0 0 0 0 0 0 = Unimplemented or Reserved Figure 3-10. MMC Control Register (MMCCTL1) Read: Anytime. . Write: Refer to each bit description. Table 3-6. MMCCTL1 Field Descriptions Field Description 7 MGRAMON Flash Memory Controller SCRATCH RAM visible in the global memory map Write: Anytime This bit is used to made the Flash Memory Controller SCRATCH RAM visible in the global memory map. 0 Not visible in the global memory map. 1 Visible in the global memory map. 5 DFIFRON Data Flash Information Row (IFR) visible in the global memory map Write: Anytime This bit is used to made the IFR sector of the Data Flash visible in the global memory map. 0 Not visible in the global memory map. 1 Visible in the global memory map. 4 PGMIFRON Program Flash Information Row (IFR) visible in the global memory map Write: Anytime This bit is used to map the IFR sector of the Program Flash to address range 0x40_000-0x40_3FFF of the global memory map. 0 Not visible in the global memory map. 1 Visible in the global memory map. 3.3.2.5 Program Page Index Register (PPAGE) Address: 0x0015 R W Reset 7 PIX7 1 Read: Anytime 6 PIX6 5 PIX5 4 PIX4 3 PIX3 2 PIX2 1 1 1 1 1 Figure 3-11. Program Page Index Register (PPAGE) 1 PIX1 1 0 PIX0 0 S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 129 Memory Mapping Control (S12XMMCV4) Write: Anytime These eight index bits are used to page 16KB blocks into the Flash page window located in the local (CPU or BDM) memory map from address 0x8000 to address 0xBFFF (see Figure 3-12). This supports accessing up to 4MB of Flash (in the Global map) within the 64KB Local map. The PPAGE register is effectively used to construct paged Flash addresses in the Local map format. The CPU has special access to read and write this register directly during execution of CALL and RTC instructions.. Global Address [22:0] 1 Bit21 Bit14 Bit13 Bit0 PPAGE Register [7:0] Address [13:0] Address: CPU Local Address or BDM Local Address Figure 3-12. PPAGE Address Mapping NOTE Writes to this register using the special access of the CALL and RTC instructions will be complete before the end of the instruction execution. Table 3-7. PPAGE Field Descriptions Field 7–0 PIX[7:0] Description Program Page Index Bits 7–0 — These page index bits are used to select which of the 256 FLASH or ROM array pages is to be accessed in the Program Page Window. The fixed 16K page from 0x4000–0x7FFF (when ROMHM = 0) is the page number 0xFD. The reset value of 0xFE ensures that there is linear Flash space available between addresses 0x4000 and 0xFFFF out of reset. The fixed 16K page from 0xC000-0xFFFF is the page number 0xFF. S12XS-Family Reference Manual, Rev. 1.03 130 PRELIMINARY Freescale Semiconductor Memory Mapping Control (S12XMMCV4) 3.3.2.6 RAM Page Index Register (RPAGE) Address: 0x0016 R W Reset 7 RP7 1 6 RP6 1 5 RP5 1 4 RP4 1 3 RP3 1 2 RP2 1 1 RP1 0 0 RP0 1 Figure 3-13. RAM Page Index Register (RPAGE) Read: Anytime Write: Anytime These eight index bits are used to page 4KB blocks into the RAM page window located in the local (CPU or BDM) memory map from address 0x1000 to address 0x1FFF (see Figure 3-14). This supports accessing up to 1022KB of RAM (in the Global map) within the 64KB Local map. The RAM page index register is effectively used to construct paged RAM addresses in the Local map format. Global Address [22:0] 0 0 0 Bit19 Bit18 Bit12 Bit11 Bit0 RPAGE Register [7:0] Address [11:0] Field 7–0 RP[7:0] Address: CPU Local Address or BDM Local Address Figure 3-14. RPAGE Address Mapping NOTE Because RAM page 0 has the same global address as the register space, it is possible to write to registers through the RAM space when RPAGE = 0x00. Table 3-8. RPAGE Field Descriptions Description RAM Page Index Bits 7–0 — These page index bits are used to select which of the 256 RAM array pages is to be accessed in the RAM Page Window. The reset value of 0xFD ensures that there is a linear RAM space available between addresses 0x1000 and 0x3FFF out of reset. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 131 Memory Mapping Control (S12XMMCV4) The fixed 4K page from 0x2000–0x2FFF of RAM is equivalent to page 254 (page number 0xFE). The fixed 4K page from 0x3000–0x3FFF of RAM is equivalent to page 255 (page number 0xFF). NOTE The page 0xFD (reset value) contains unimplemented area in the range not occupied by RAM if RAMSIZE is less than 12KB (Refer to Section 3.4.2.3, “Implemented Memory Map). The two fixed 4KB pages (0xFE, 0xFF) contain unimplemented area in the range not occupied by RAM if RAMSIZE is less than 8KB (Refer to Section 3.4.2.3, “Implemented Memory Map). S12XS-Family Reference Manual, Rev. 1.03 132 PRELIMINARY Freescale Semiconductor Memory Mapping Control (S12XMMCV4) 3.3.2.7 Data FLASH Page Index Register (EPAGE) Address: 0x0017 7 R EP7 W 6 EP6 5 EP5 4 EP4 3 EP3 2 EP2 1 EP1 0 EP0 Reset 1 1 1 1 1 1 1 0 Figure 3-15. Data FLASH Page Index Register (EPAGE) Read: Anytime Write: Anytime These eight index bits are used to page 1KB blocks into the Data FLASH page window located in the local (CPU or BDM) memory map from address 0x0800 to address 0x0BFF (see Figure 3-16). This supports accessing up to 256KB of Data FLASH (in the Global map) within the 64KB Local map. The Data FLASH page index register is effectively used to construct paged Data FLASH addresses in the Local map format. Global Address [22:0] 0 0 1 0 0 Bit17 Bit16 Bit10 Bit9 Bit0 EPAGE Register [7:0] Address [9:0] Address: CPU Local Address or BDM Local Address Figure 3-16. EPAGE Address Mapping Table 3-9. EPAGE Field Descriptions Field 7–0 EP[7:0] Description Data FLASH Page Index Bits 7–0 — These page index bits are used to select which of the 256 Data FLASH array pages is to be accessed in the Data FLASH Page Window. The reset value of 0xFE ensures that there is a linear Data FLASH space available between addresses 0x0800 and 0x0FFF out of reset. The fixed 1K page 0x0C00–0x0FFF of Data FLASH is equivalent to page 255 (page number 0xFF). S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 133 Memory Mapping Control (S12XMMCV4) 3.4 Functional Description The MMC block performs several basic functions of the S12X sub-system operation: MCU operation modes, priority control, address mapping, select signal generation and access limitations for the system. Each aspect is described in the following subsections. 3.4.1 MCU Operating Mode • Normal single-chip mode There is no external bus in this mode. The MCU program is executed from the internal memory and no external accesses are allowed. • Special single-chip mode This mode is generally used for debugging single-chip operation, boot-strapping or security related operations. The active background debug mode is in control of the CPU code execution and the BDM firmware is waiting for serial commands sent through the BKGD pin. There is no external bus in this mode. 3.4.2 Memory Map Scheme 3.4.2.1 CPU and BDM Memory Map Scheme The BDM firmware lookup tables and BDM register memory locations share addresses with other modules; however they are not visible in the global memory map during user’s code execution. The BDM memory resources are enabled only during the READ_BD and WRITE_BD access cycles to distinguish between accesses to the BDM memory area and accesses to the other modules. (Refer to BDM Block Guide for further details). When the MCU enters active BDM mode, the BDM firmware lookup tables and the BDM registers become visible in the local memory map in the range 0xFF00-0xFFFF (global address 0x7F_FF00 0x7F_FFFF) and the CPU begins execution of firmware commands or the BDM begins execution of hardware commands. The resources which share memory space with the BDM module will not be visible in the global memory map during active BDM mode. Please note that after the MCU enters active BDM mode the BDM firmware lookup tables and the BDM registers will also be visible between addresses 0xBF00 and 0xBFFF if the PPAGE register contains value of 0xFF. S12XS-Family Reference Manual, Rev. 1.03 134 PRELIMINARY Freescale Semiconductor CPU and BDM Local Memory Map CPU和BDM 本地内 存映射 Memory Mapping Control (S12XMMCV4) Global Memory Map 0x00_0000 0x00_0800 0x00_1000 2KB REGISTERS 2KB RAM RAM 253*4KB paged 1M minus 2KB 256KB 2.75MB 0x0000 2KB REGISTERS 0x0800 1KB Data Flash window 0x0C00 Reserved 0x1000 0x2000 4KB RAM window 8KB RAM 0x4000 Unpaged 16KB FLASH 0x8000 EPAGE RPAGE 0x0F_E000 0x10_0000 8KB RAM Data FLASH 256*1KB paged 0x13_FC00 0x14_0000 Unimplemented Space 16KB FLASH window PPAGE 0x40_0000 0xC000 Unpaged 16KB FLASH FLASH 253 *16KB paged 0xFFFF Reset Vectors 0x7F_4000 0x7F_8000 0x7F_C000 0x7F_FFFF 16KB FLASH (PPAGE 0xFD) 16KB FLASH (PPAGE 0xFE) 16KB FLASH (PPAGE 0xFF) Figure 3-17. Expansion of the Local Address Map 4MB S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 135 Memory Mapping Control (S12XMMCV4) 3.4.2.1.1 Expansion of the Local Address Map Expansion of the CPU Local Address Map The program page index register in MMC allows accessing up to 4MB of FLASH or ROM in the global memory map by using the eight page index bits to page 256 16KB blocks into the program page window located from address 0x8000 to address 0xBFFF in the local CPU memory map. The page value for the program page window is stored in the PPAGE register. The value of the PPAGE register can be read or written by normal memory accesses as well as by the CALL and RTC instructions (see Section 3.5.1, “CALL and RTC Instructions). Control registers, vector space and parts of the on-chip memories are located in unpaged portions of the 64KB local CPU address space. The starting address of an interrupt service routine must be located in unpaged memory unless the user is certain that the PPAGE register will be set to the appropriate value when the service routine is called. However an interrupt service routine can call other routines that are in paged memory. The upper 16KB block of the local CPU memory space (0xC000–0xFFFF) is unpaged. It is recommended that all reset and interrupt vectors point to locations in this area or to the other unpaged sections of the local CPU memory map. The RAM page index register allows accessing up to 1MB minus 2KB of RAM in the global memory map by using the eight RPAGE index bits to page 4KB blocks into the RAM page window located in the local CPU memory space from address 0x1000 to address 0x1FFF. The Data FLASH page index register EPAGE allows accessing up to 256KB of Data Flash in the system by using the eight EPAGE index bits to page 1KB blocks into the Data FLASH page window located in the local CPU memory space from address 0x0800 to address 0x0BFF. S12XS-Family Reference Manual, Rev. 1.03 136 PRELIMINARY Freescale Semiconductor Memory Mapping Control (S12XMMCV4) Expansion of the BDM Local Address Map PPAGE, RPAGE, and EPAGE registers are also used for the expansion of the BDM local address to the global address. These registers can be read and written by the BDM. The BDM expansion scheme is the same as the CPU expansion scheme. 3.4.2.2 Global Addresses Based on the Global Page CPU Global Addresses Based on the Global Page The seven global page index bits allow access to the full 8MB address map that can be accessed with 23 address bits. This provides an alternative way to access all of the various pages of FLASH, RAM and Data FLASH. The GPAGE Register is used only when the CPU is executing a global instruction (see Section 3.3.2.2, “Global Page Index Register (GPAGE)). The generated global address is the result of concatenation of the CPU local address [15:0] with the GPAGE register [22:16] (see Figure 3-7). BDM Global Addresses Based on the Global Page The seven BDMGPR Global Page index bits allow access to the full 8MB address map that can be accessed with 23 address bits. This provides an alternative way to access all of the various pages of FLASH, RAM and Data FLASH. The BDM global page index register (BDMGPR) is used only in the case the CPU is executing a firmware command which uses a global instruction (like GLDD, GSTD) or by a BDM hardware command (like WRITE_W, WRITE_BYTE, READ_W, READ_BYTE). See the BDM Block Guide for further details. The generated global address is a result of concatenation of the BDM local address with the BDMGPR register [22:16] in the case of a hardware command or concatenation of the CPU local address and the BDMGPR register [22:16] in the case of a firmware command (see Figure 3-18). S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 137 Memory Mapping Control (S12XMMCV4) BDM HARDWARE COMMAND Global Address [22:0] Bit22 Bit16 Bit15 Bit0 BDMGPR Register [6:0] BDM Local Address Bit22 BDM FIRMWARE COMMAND Global Address [22:0] Bit16 Bit15 Bit0 BDMGPR Register [6:0] CPU Local Address Figure 3-18. BDMGPR Address Mapping 3.4.2.3 Implemented Memory Map The global memory spaces reserved for the internal resources (RAM, Data FLASH, and FLASH) are not determined by the MMC module. Size of the individual internal resources are however fixed in the design of the device cannot be changed by the user. Please refer to the SoC Guide for further details. Figure 3-19 and Table 3-10 show the memory spaces occupied by the on-chip resources. Please note that the memory spaces have fixed top addresses. Table 3-10. Global Implemented Memory Space Internal Resource $Address RAM RAM_LOW = 0x10_0000 minus RAMSIZE1 Data FLASH DF_HIGH = 0x10_0000 plus DFLASHSIZE2 FLASH FLASH_LOW = 0x80_0000 minus FLASHSIZE3 1 RAMSIZE is the hexadecimal value of RAM SIZE in Bytes 2 DFLASHSIZE is the hexadecimal value of DFLASH SIZE in Bytes 3 FLASHSIZE is the hexadecimal value of FLASH SIZE in Bytes S12XS-Family Reference Manual, Rev. 1.03 138 PRELIMINARY Freescale Semiconductor Memory Mapping Control (S12XMMCV4) In single-chip modes accesses by the CPU (except for firmware commands) to any of the unimplemented areas (see Figure 3-19) will result in an illegal access reset (system reset) in case of no MPU error. BDM accesses to the unimplemented areas are allowed but the data will be undefined.No misaligned word access from the BDM module will occur; these accesses are blocked in the BDM module (Refer to BDM Block Guide). Misaligned word access to the last location of RAM is performed but the data will be undefined. Misaligned word access to the last location of any global page (64KB) by any global instruction, is performed by accessing the last byte of the page and the first byte of the same page, considering the above mentioned misaligned access cases. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 139 DFLASHSIZE RAMSIZE Memory Mapping Control (S12XMMCV4) CPU and BDM Local Memory Map 0x0000 2K REGISTERS 0x0800 1K Data Flash window 0x0C00 Reserved 0x1000 0x2000 4K RAM window 8K RAM 0x4000 Unpaged 16K FLASH 0x8000 16K FLASH window EPAGE RPAGE PPAGE 0xC000 0xFFFF Unpaged 16K FLASH Reset Vectors Global Memory Map 0x00_0000 0x00_07FF 2K REGISTERS Unimplemented RAM RAM_LOW RAM 0x0F_FFFF DF_HIGH Data FLASH Data FLASH Resources 0x13_FFFF Unimplemented Space 0x3F_FFFF Unimplemented FLASH FLASH_LOW FLASH FLASHSIZE 0x7F_FFFF Figure 3-19. S12X CPU & BDM Global Address Mapping S12XS-Family Reference Manual, Rev. 1.03 140 PRELIMINARY Freescale Semiconductor Memory Mapping Control (S12XMMCV4) 3.4.3 Chip Bus Control The MMC controls the address buses and the data buses that interface the S12X masters (CPU, BDM ) with the rest of the system (master buses). In addition the MMC handles all CPU read data bus swapping operations. All internal resources are connected to specific target buses (see Figure 3-20). MMC BDM S12X1 Address Decoder & Priority CPU S12X0 DBG Target Bus Controller XBUS0 Data FLASH PGMFLASH RAM Peripherals Figure 3-20. MMC Block Diagram S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 141 Memory Mapping Control (S12XMMCV4) 3.4.3.1 Master Bus Prioritization regarding access conflicts on Target Buses The arbitration scheme allows only one master to be connected to a target at any given time. The following rules apply when prioritizing accesses from different masters to the same target bus: • CPU always has priority over BDM . • BDM has priority over CPU when its access is stalled for more than 128 cycles. In the later case the suspect master will be stalled after finishing the current operation and the BDM will gain access to the bus. 3.5 Initialization/Application Information 3.5.1 CALL and RTC Instructions CALL and RTC instructions are uninterruptible CPU instructions that automate page switching in the program page window. The CALL instruction is similar to the JSR instruction, but the subroutine that is called can be located anywhere in the local address space or in any Flash or ROM page visible through the program page window. The CALL instruction calculates and stacks a return address, stacks the current PPAGE value and writes a new instruction-supplied value to the PPAGE register. The PPAGE value controls which of the 256 possible pages is visible through the 16KB program page window in the 64KB local CPU memory map. Execution then begins at the address of the called subroutine. During the execution of the CALL instruction, the CPU performs the following steps: 1. Writes the current PPAGE value into an internal temporary register and writes the new instructionsupplied PPAGE value into the PPAGE register 2. Calculates the address of the next instruction after the CALL instruction (the return address) and pushes this 16-bit value onto the stack 3. Pushes the temporarily stored PPAGE value onto the stack 4. Calculates the effective address of the subroutine, refills the queue and begins execution at the new address This sequence is uninterruptible. There is no need to inhibit interrupts during the CALL instruction execution. A CALL instruction can be performed from any address to any other address in the local CPU memory space. The PPAGE value supplied by the instruction is part of the effective address of the CPU. For all addressing mode variations (except indexed-indirect modes) the new page value is provided by an immediate operand in the instruction. In indexed-indirect variations of the CALL instruction a pointer specifies memory locations where the new page value and the address of the called subroutine are stored. Using indirect addressing for both the new page value and the address within the page allows usage of values calculated at run time rather than immediate values that must be known at the time of assembly. The RTC instruction terminates subroutines invoked by a CALL instruction. The RTC instruction unstacks the PPAGE value and the return address and refills the queue. Execution resumes with the next instruction after the CALL instruction. S12XS-Family Reference Manual, Rev. 1.03 142 PRELIMINARY Freescale Semiconductor Memory Mapping Control (S12XMMCV4) During the execution of an RTC instruction the CPU performs the following steps: 1. Pulls the previously stored PPAGE value from the stack 2. Pulls the 16-bit return address from the stack and loads it into the PC 3. Writes the PPAGE value into the PPAGE register 4. Refills the queue and resumes execution at the return address This sequence is uninterruptible. The RTC can be executed from anywhere in the local CPU memory space. The CALL and RTC instructions behave like JSR and RTS instruction, they however require more execution cycles. Usage of JSR/RTS instructions is therefore recommended when possible and CALL/RTC instructions should only be used when needed. The JSR and RTS instructions can be used to access subroutines that are already present in the local CPU memory map (i.e. in the same page in the program memory page window for example). However calling a function located in a different page requires usage of the CALL instruction. The function must be terminated by the RTC instruction. Because the RTC instruction restores contents of the PPAGE register from the stack, functions terminated with the RTC instruction must be called using the CALL instruction even when the correct page is already present in the memory map. This is to make sure that the correct PPAGE value will be present on stack at the time of the RTC instruction execution. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 143 Memory Mapping Control (S12XMMCV4) S12XS-Family Reference Manual, Rev. 1.03 144 PRELIMINARY Freescale Semiconductor Chapter 4 Interrupt (S12XINTV2) Table 4-1. Revision History Revision Number V02.00 Revision Date 01 Jul 2005 V02.04 V02.05 V02.06 11 Jan 2007 20 Mar 2007 07 Jan 2008 Sections Affected 4.1.2/4-146 4.3.2.2/4-151 4.3.2.4/4-152 4.4.6/4-158 4.5.3.1/4-160 Description of Changes Initial V2 release, added new features: - XGATE threads can be interrupted. - SYS instruction vector. - Access violation interrupt vectors. - Added Notes for devices without XGATE module. - Fixed priority definition for software exceptions. - Added clarification of “Wake-up from STOP or WAIT by XIRQ with X bit set” feature. 4.1 Introduction The XINT module decodes the priority of all system exception requests and provides the applicable vector for processing the exception to either the CPU or the XGATE module. The XINT module supports: • I bit and X bit maskable interrupt requests • One non-maskable unimplemented op-code trap • One non-maskable software interrupt (SWI) or background debug mode request • One non-maskable system call interrupt (SYS) • Three non-maskable access violation interrupt • One spurious interrupt vector request • Three system reset vector requests Each of the I bit maskable interrupt requests can be assigned to one of seven priority levels supporting a flexible priority scheme. For interrupt requests that are configured to be handled by the CPU, the priority scheme can be used to implement nested interrupt capability where interrupts from a lower level are automatically blocked if a higher level interrupt is being processed. Interrupt requests configured to be handled by the XGATE module can be nested one level deep. NOTE The HPRIO register and functionality of the original S12 interrupt module is no longer supported, since it is superseded by the 7-level interrupt request priority scheme. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 145 Interrupt (S12XINTV2) 4.1.1 Glossary The following terms and abbreviations are used in the document. Table 4-2. Terminology Term CCR DMA INT IPL ISR MCU XGATE IRQ XIRQ Meaning Condition Code Register (in the S12X CPU) Direct Memory Access Interrupt Interrupt Processing Level Interrupt Service Routine Micro-Controller Unit refers to the XGATE co-processor; XGATE is an optional feature refers to the interrupt request associated with the IRQ pin refers to the interrupt request associated with the XIRQ pin 4.1.2 Features • Interrupt vector base register (IVBR) • One spurious interrupt vector (at address vector base1 + 0x0010). • One non-maskable system call interrupt vector request (at address vector base + 0x0012). • Three non-maskable access violation interrupt vector requests (at address vector base + 0x0014− 0x0018). • 2–109 I bit maskable interrupt vector requests (at addresses vector base + 0x001A–0x00F2). • Each I bit maskable interrupt request has a configurable priority level and can be configured to be handled by either the CPU or the XGATE module2. • I bit maskable interrupts can be nested, depending on their priority levels. • One X bit maskable interrupt vector request (at address vector base + 0x00F4). • One non-maskable software interrupt request (SWI) or background debug mode vector request (at address vector base + 0x00F6). • One non-maskable unimplemented op-code trap (TRAP) vector (at address vector base + 0x00F8). • Three system reset vectors (at addresses 0xFFFA–0xFFFE). • Determines the highest priority XGATE and interrupt vector requests, drives the vector to the XGATE module or to the bus on CPU request, respectively. • Wakes up the system from stop or wait mode when an appropriate interrupt request occurs or whenever XIRQ is asserted, even if X interrupt is masked. • XGATE can wake up and execute code, even with the CPU remaining in stop or wait mode. 1. The vector base is a 16-bit address which is accumulated from the contents of the interrupt vector base register (IVBR, used as upper byte) and 0x00 (used as lower byte). 2. The IRQ interrupt can only be handled by the CPU S12XS-Family Reference Manual, Rev. 1.03 146 PRELIMINARY Freescale Semiconductor Interrupt (S12XINTV2) 4.1.3 Modes of Operation • Run mode This is the basic mode of operation. • Wait mode In wait mode, the XINT module is frozen. It is however capable of either waking up the CPU if an interrupt occurs or waking up the XGATE if an XGATE request occurs. Please refer to Section 4.5.3, “Wake Up from Stop or Wait Mode” for details. • Stop Mode In stop mode, the XINT module is frozen. It is however capable of either waking up the CPU if an interrupt occurs or waking up the XGATE if an XGATE request occurs. Please refer to Section 4.5.3, “Wake Up from Stop or Wait Mode” for details. • Freeze mode (BDM active) In freeze mode (BDM active), the interrupt vector base register is overridden internally. Please refer to Section 4.3.2.1, “Interrupt Vector Base Register (IVBR)” for details. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 147 Priority Decoder To CPU Interrupt (S12XINTV2) 4.1.4 Block Diagram Figure 4-1 shows a block diagram of the XINT module. Peripheral Interrupt Requests Non I Bit Maskable Channels IRQ Channel Wake Up CPU Vector Address RQST One Set Per Channel (Up to 108 Channels) XGATE Requests PRIOLVL2 PRIOLVL1 PRIOLVL0 Interrupt Requests INT_XGPRIO IVBR New IPL Current IPL Priority Decoder Wake up XGATE Vector ID XGATE Interrupts To XGATE Module RQST XGATE Request Route, PRIOLVLn Priority Level = bits from the channel configuration in the associated configuration register INT_XGPRIO = XGATE Interrupt Priority IVBR = Interrupt Vector Base IPL = Interrupt Processing Level Figure 4-1. XINT Block Diagram 4.2 External Signal Description The XINT module has no external signals. S12XS-Family Reference Manual, Rev. 1.03 148 PRELIMINARY Freescale Semiconductor Interrupt (S12XINTV2) 4.3 Memory Map and Register Definition This section provides a detailed description of all registers accessible in the XINT module. 4.3.1 Module Memory Map Table 4-3 gives an overview over all XINT module registers. Table 4-3. XINT Memory Map Address 0x0120 0x0121 0x0122–0x0125 0x0126 0x0127 0x0128 0x0129 0x012A 0x012B 0x012C 0x012D 0x012E 0x012F Use RESERVED Interrupt Vector Base Register (IVBR) RESERVED XGATE Interrupt Priority Configuration Register (INT_XGPRIO) Interrupt Request Configuration Address Register (INT_CFADDR) Interrupt Request Configuration Data Register 0 (INT_CFDATA0) Interrupt Request Configuration Data Register 1 (INT_CFDATA1) Interrupt Request Configuration Data Register 2 (INT_CFDATA2 Interrupt Request Configuration Data Register 3 (INT_CFDATA3) Interrupt Request Configuration Data Register 4 (INT_CFDATA4) Interrupt Request Configuration Data Register 5 (INT_CFDATA5) Interrupt Request Configuration Data Register 6 (INT_CFDATA6) Interrupt Request Configuration Data Register 7 (INT_CFDATA7) Access — R/W — R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 149 Interrupt (S12XINTV2) 4.3.2 Register Descriptions This section describes in address order all the XINT module registers and their individual bits. Address Register Name Bit 7 6 0x0121 IVBR R W 5 4 3 IVB_ADDR[7:0]7 0x0126 INT_XGPRIO R 0 0 0 0 0 W 0x0127 INT_CFADDR R 0 INT_CFADDR[7:4] W 0x0128 INT_CFDATA0 R 0 0 0 0 RQST W 0x0129 INT_CFDATA1 R 0 0 0 0 RQST W 0x012A INT_CFDATA2 R 0 0 0 0 RQST W 0x012B INT_CFDATA3 R 0 0 0 0 RQST W 0x012C INT_CFDATA4 R 0 0 0 0 RQST W 0x012D INT_CFDATA5 R 0 0 0 0 RQST W 0x012E INT_CFDATA6 R 0 0 0 0 RQST W 0x012F INT_CFDATA7 R 0 0 0 0 RQST W = Unimplemented or Reserved Figure 4-2. XINT Register Summary 2 1 Bit 0 XILVL[2:0] 0 0 0 PRIOLVL[2:0] PRIOLVL[2:0] PRIOLVL[2:0] PRIOLVL[2:0] PRIOLVL[2:0] PRIOLVL[2:0] PRIOLVL[2:0] PRIOLVL[2:0] S12XS-Family Reference Manual, Rev. 1.03 150 PRELIMINARY Freescale Semiconductor 4.3.2.1 Interrupt Vector Base Register (IVBR) Interrupt (S12XINTV2) Address: 0x0121 7 6 5 4 3 2 1 0 R IVB_ADDR[7:0] W Reset 1 1 1 1 1 1 1 1 Figure 4-3. Interrupt Vector Base Register (IVBR) Read: Anytime Write: Anytime Table 4-4. IVBR Field Descriptions Field Description 7–0 Interrupt Vector Base Address Bits — These bits represent the upper byte of all vector addresses. Out of IVB_ADDR[7:0] reset these bits are set to 0xFF (i.e., vectors are located at 0xFF10–0xFFFE) to ensure compatibility to previous S12 microcontrollers. Note: A system reset will initialize the interrupt vector base register with “0xFF” before it is used to determine the reset vector address. Therefore, changing the IVBR has no effect on the location of the three reset vectors (0xFFFA–0xFFFE). Note: If the BDM is active (i.e., the CPU is in the process of executing BDM firmware code), the contents of IVBR are ignored and the upper byte of the vector address is fixed as “0xFF”. 4.3.2.2 XGATE Interrupt Priority Configuration Register (INT_XGPRIO) Address: 0x0126 7 6 5 4 3 2 1 0 R 0 0 0 0 0 W XILVL[2:0] Reset 0 0 0 0 0 0 0 1 = Unimplemented or Reserved Figure 4-4. XGATE Interrupt Priority Configuration Register (INT_XGPRIO) Read: Anytime Write: Anytime Table 4-5. INT_XGPRIO Field Descriptions Field Description 2–0 XILVL[2:0] XGATE Interrupt Priority Level — The XILVL[2:0] bits configure the shared interrupt level of the XGATE interrupts coming from the XGATE module. Out of reset the priority is set to the lowest active level (“1”). Note: If the XGATE module is not available on the device, write accesses to this register are ignored and read accesses to this register will return all 0. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 151 Interrupt (S12XINTV2) 4.3.2.3 Priority low high Table 4-6. XGATE Interrupt Priority Levels XILVL2 0 0 0 0 1 1 1 1 XILVL1 0 0 1 1 0 0 1 1 XILVL0 0 1 0 1 0 1 0 1 Meaning Interrupt request is disabled Priority level 1 Priority level 2 Priority level 3 Priority level 4 Priority level 5 Priority level 6 Priority level 7 Interrupt Request Configuration Address Register (INT_CFADDR) Address: 0x0127 7 6 5 4 3 2 1 0 R INT_CFADDR[7:4] W 0 0 0 0 Reset 0 0 0 1 0 0 0 0 = Unimplemented or Reserved Figure 4-5. Interrupt Configuration Address Register (INT_CFADDR) Read: Anytime Write: Anytime Table 4-7. INT_CFADDR Field Descriptions Field Description 7–4 Interrupt Request Configuration Data Register Select Bits — These bits determine which of the 128 INT_CFADDR[7:4] configuration data registers are accessible in the 8 register window at INT_CFDATA0–7. The hexadecimal value written to this register corresponds to the upper nibble of the lower byte of the address of the interrupt vector, i.e., writing 0xE0 to this register selects the configuration data register block for the 8 interrupt vector requests starting with vector at address (vector base + 0x00E0) to be accessible as INT_CFDATA0–7. Note: Writing all 0s selects non-existing configuration registers. In this case write accesses to INT_CFDATA0–7 will be ignored and read accesses will return all 0. 4.3.2.4 Interrupt Request Configuration Data Registers (INT_CFDATA0–7) The eight register window visible at addresses INT_CFDATA0–7 contains the configuration data for the block of eight interrupt requests (out of 128) selected by the interrupt configuration address register (INT_CFADDR) in ascending order. INT_CFDATA0 represents the interrupt configuration data register of the vector with the lowest address in this block, while INT_CFDATA7 represents the interrupt configuration data register of the vector with the highest address, respectively. S12XS-Family Reference Manual, Rev. 1.03 152 PRELIMINARY Freescale Semiconductor Interrupt (S12XINTV2) Address: 0x0128 7 6 5 4 3 2 1 0 R 0 0 0 0 RQST W PRIOLVL[2:0] Reset 0 0 0 0 0 0 0 11 = Unimplemented or Reserved Figure 4-6. Interrupt Request Configuration Data Register 0 (INT_CFDATA0) 1 Please refer to the notes following the PRIOLVL[2:0] description below. Address: 0x0129 7 6 5 4 3 2 1 0 R 0 0 0 0 RQST W PRIOLVL[2:0] Reset 0 0 0 0 0 0 0 11 = Unimplemented or Reserved Figure 4-7. Interrupt Request Configuration Data Register 1 (INT_CFDATA1) 1 Please refer to the notes following the PRIOLVL[2:0] description below. Address: 0x012A 7 6 5 4 3 2 1 0 R 0 0 0 0 RQST W PRIOLVL[2:0] Reset 0 0 0 0 0 0 0 11 = Unimplemented or Reserved Figure 4-8. Interrupt Request Configuration Data Register 2 (INT_CFDATA2) 1 Please refer to the notes following the PRIOLVL[2:0] description below. Address: 0x012B 7 6 5 4 3 2 1 0 R 0 0 0 0 RQST W PRIOLVL[2:0] Reset 0 0 0 0 0 0 0 11 = Unimplemented or Reserved Figure 4-9. Interrupt Request Configuration Data Register 3 (INT_CFDATA3) 1 Please refer to the notes following the PRIOLVL[2:0] description below. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 153 Interrupt (S12XINTV2) Address: 0x012C 7 6 5 4 3 2 1 0 R 0 0 0 0 RQST W PRIOLVL[2:0] Reset 0 0 0 0 0 0 0 11 = Unimplemented or Reserved Figure 4-10. Interrupt Request Configuration Data Register 4 (INT_CFDATA4) 1 Please refer to the notes following the PRIOLVL[2:0] description below. Address: 0x012D 7 6 5 4 3 2 1 0 R 0 0 0 0 RQST W PRIOLVL[2:0] Reset 0 0 0 0 0 0 0 11 = Unimplemented or Reserved Figure 4-11. Interrupt Request Configuration Data Register 5 (INT_CFDATA5) 1 Please refer to the notes following the PRIOLVL[2:0] description below. Address: 0x012E 7 6 5 4 3 2 1 0 R 0 0 0 0 RQST W PRIOLVL[2:0] Reset 0 0 0 0 0 0 0 11 = Unimplemented or Reserved Figure 4-12. Interrupt Request Configuration Data Register 6 (INT_CFDATA6) 1 Please refer to the notes following the PRIOLVL[2:0] description below. Address: 0x012F 7 6 5 4 3 2 1 0 R 0 0 0 0 RQST W PRIOLVL[2:0] Reset 0 0 0 0 0 0 0 11 = Unimplemented or Reserved Figure 4-13. Interrupt Request Configuration Data Register 7 (INT_CFDATA7) 1 Please refer to the notes following the PRIOLVL[2:0] description below. Read: Anytime Write: Anytime S12XS-Family Reference Manual, Rev. 1.03 154 PRELIMINARY Freescale Semiconductor Interrupt (S12XINTV2) Table 4-8. INT_CFDATA0–7 Field Descriptions Field Description 7 RQST XGATE Request Enable — This bit determines if the associated interrupt request is handled by the CPU or by the XGATE module. 0 Interrupt request is handled by the CPU 1 Interrupt request is handled by the XGATE module Note: The IRQ interrupt cannot be handled by the XGATE module. For this reason, the configuration register for vector (vector base + 0x00F2) = IRQ vector address) does not contain a RQST bit. Writing a 1 to the location of the RQST bit in this register will be ignored and a read access will return 0. Note: If the XGATE module is not available on the device, writing a 1 to the location of the RQST bit in this register will be ignored and a read access will return 0. 2–0 Interrupt Request Priority Level Bits — The PRIOLVL[2:0] bits configure the interrupt request priority level of PRIOLVL[2:0] the associated interrupt request. Out of reset all interrupt requests are enabled at the lowest active level (“1”) to provide backwards compatibility with previous S12 interrupt controllers. Please also refer to Table 4-9 for available interrupt request priority levels. Note: Write accesses to configuration data registers of unused interrupt channels will be ignored and read accesses will return all 0. For information about what interrupt channels are used in a specific MCU, please refer to the Device Reference Manual of that MCU. Note: When vectors (vector base + 0x00F0–0x00FE) are selected by writing 0xF0 to INT_CFADDR, writes to INT_CFDATA2–7 (0x00F4–0x00FE) will be ignored and read accesses will return all 0s. The corresponding vectors do not have configuration data registers associated with them. Note: When vectors (vector base + 0x0010–0x001E) are selected by writing 0x10 to INT_CFADDR, writes to INT_CFDATA1–INT_CFDATA4 (0x0012–0x0018) will be ignored and read accesses will return all 0s. The corresponding vectors do not have configuration data registers associated with them. Note: Write accesses to the configuration register for the spurious interrupt vector request (vector base + 0x0010) will be ignored and read accesses will return 0x07 (request is handled by the CPU, PRIOLVL = 7). Priority low high Table 4-9. Interrupt Priority Levels PRIOLVL2 0 0 0 0 1 1 1 1 PRIOLVL1 0 0 1 1 0 0 1 1 PRIOLVL0 0 1 0 1 0 1 0 1 Meaning Interrupt request is disabled Priority level 1 Priority level 2 Priority level 3 Priority level 4 Priority level 5 Priority level 6 Priority level 7 4.4 Functional Description The XINT module processes all exception requests to be serviced by the CPU module. These exceptions include interrupt vector requests and reset vector requests. Each of these exception types and their overall priority level is discussed in the subsections below. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 155 Interrupt (S12XINTV2) 4.4.1 S12X Exception Requests The CPU handles both reset requests and interrupt requests. The XINT module contains registers to configure the priority level of each I bit maskable interrupt request which can be used to implement an interrupt priority scheme. This also includes the possibility to nest interrupt requests. A priority decoder is used to evaluate the priority of a pending interrupt request. 4.4.2 Interrupt Prioritization After system reset all interrupt requests with a vector address lower than or equal to (vector base + 0x00F2) are enabled, are set up to be handled by the CPU and have a pre-configured priority level of 1. Exceptions to this rule are the non-maskable interrupt requests and the spurious interrupt vector request at (vector base + 0x0010) which cannot be disabled, are always handled by the CPU and have a fixed priority levels. A priority level of 0 effectively disables the associated I bit maskable interrupt request. If more than one interrupt request is configured to the same interrupt priority level the interrupt request with the higher vector address wins the prioritization. The following conditions must be met for an I bit maskable interrupt request to be processed. 1. The local interrupt enabled bit in the peripheral module must be set. 2. The setup in the configuration register associated with the interrupt request channel must meet the following conditions: a) The XGATE request enable bit must be 0 to have the CPU handle the interrupt request. b) The priority level must be set to non zero. c) The priority level must be greater than the current interrupt processing level in the condition code register (CCR) of the CPU (PRIOLVL[2:0] > IPL[2:0]). 3. The I bit in the condition code register (CCR) of the CPU must be cleared. 4. There is no access violation interrupt request pending. 5. There is no SYS, SWI, BDM, TRAP, or XIRQ request pending. NOTE All non I bit maskable interrupt requests always have higher priority than I bit maskable interrupt requests. If an I bit maskable interrupt request is interrupted by a non I bit maskable interrupt request, the currently active interrupt processing level (IPL) remains unaffected. It is possible to nest non I bit maskable interrupt requests, e.g., by nesting SWI or TRAP calls. 4.4.2.1 Interrupt Priority Stack The current interrupt processing level (IPL) is stored in the condition code register (CCR) of the CPU. This way the current IPL is automatically pushed to the stack by the standard interrupt stacking procedure. The new IPL is copied to the CCR from the priority level of the highest priority active interrupt request channel which is configured to be handled by the CPU. The copying takes place when the interrupt vector is fetched. The previous IPL is automatically restored by executing the RTI instruction. S12XS-Family Reference Manual, Rev. 1.03 156 PRELIMINARY Freescale Semiconductor Interrupt (S12XINTV2) 4.4.3 XGATE Requests If the XGATE module is implemented on the device, the XINT module is also used to process all exception requests to be serviced by the XGATE module. The overall priority level of those exceptions is discussed in the subsections below. 4.4.3.1 XGATE Request Prioritization An interrupt request channel is configured to be handled by the XGATE module, if the RQST bit of the associated configuration register is set to 1 (please refer to Section 4.3.2.4, “Interrupt Request Configuration Data Registers (INT_CFDATA0–7)”). The priority level configuration (PRIOLVL) for this channel becomes the XGATE priority which will be used to determine the highest priority XGATE request to be serviced next by the XGATE module. Additionally, XGATE interrupts may be raised by the XGATE module by setting one or more of the XGATE channel interrupt flags (by using the SIF instruction). This will result in an CPU interrupt with vector address vector base + (2 * channel ID number), where the channel ID number corresponds to the highest set channel interrupt flag, if the XGIE and channel RQST bits are set. The shared interrupt priority for the XGATE interrupt requests is taken from the XGATE interrupt priority configuration register (please refer to Section 4.3.2.2, “XGATE Interrupt Priority Configuration Register (INT_XGPRIO)”). If more than one XGATE interrupt request channel becomes active at the same time, the channel with the highest vector address wins the prioritization. 4.4.4 Priority Decoders The XINT module contains priority decoders to determine the priority for all interrupt requests pending for the respective target. There are two priority decoders, one for each interrupt request target, CPU or XGATE. The function of both priority decoders is basically the same with one exception: the priority decoder for the XGATE module does not take the current XGATE thread processing level into account. Instead, XGATE requests are handed to the XGATE module including a 1-bit priority identifier. The XGATE module uses this additional information to decide if the new request can interrupt a currently running thread. The 1-bit priority identifier corresponds to the most significant bit of the priority level configuration of the requesting channel. This means that XGATE requests with priority levels 4, 5, 6 or 7 can interrupt running XGATE threads with priority levels 1, 2 and 3. A CPU interrupt vector is not supplied until the CPU requests it. Therefore, it is possible that a higher priority interrupt request could override the original exception which caused the CPU to request the vector. In this case, the CPU will receive the highest priority vector and the system will process this exception instead of the original request. If the interrupt source is unknown (for example, in the case where an interrupt request becomes inactive after the interrupt has been recognized, but prior to the vector request), the vector address supplied to the CPU will default to that of the spurious interrupt vector. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 157 Interrupt (S12XINTV2) NOTE Care must be taken to ensure that all exception requests remain active until the system begins execution of the applicable service routine; otherwise, the exception request may not get processed at all or the result may be a spurious interrupt request (vector at address (vector base + 0x0010)). 4.4.5 Reset Exception Requests The XINT module supports three system reset exception request types (for details please refer to the Clock and Reset Generator module (CRG)): 1. Pin reset, power-on reset, low-voltage reset, or illegal address reset 2. Clock monitor reset request 3. COP watchdog reset request 4.4.6 Exception Priority The priority (from highest to lowest) and address of all exception vectors issued by the XINT module upon request by the CPU is shown in Table 4-10. Generally, all non-maskable interrupts have higher priorities than maskable interrupts. Please note that between the three software interrupts (Unimplemented op-code trap request, SWI/BGND request, SYS request) there is no real priority defined because they cannot occur simultaneously (the S12XCPU executes one instruction at a time). Table 4-10. Exception Vector Map and Priority Vector Address1 Source 0xFFFE Pin reset, power-on reset, low-voltage reset, illegal address reset 0xFFFC Clock monitor reset 0xFFFA COP watchdog reset (Vector base + 0x00F8) Unimplemented op-code trap (Vector base + 0x00F6) Software interrupt instruction (SWI) or BDM vector request (Vector base + 0x0012) System call interrupt instruction (SYS) (Vector base + 0x0018) (Vector base + 0x0016) (Vector base + 0x0014) (reserved for future use) XGATE Access violation interrupt request2 CPU Access violation interrupt request3 (Vector base + 0x00F4) XIRQ interrupt request (Vector base + 0x00F2) IRQ interrupt request (Vector base + 0x00F0–0x001A) Device specific I bit maskable interrupt sources (priority determined by the associated configuration registers, in descending order) (Vector base + 0x0010) Spurious interrupt 1 16 bits vector address based 2 only implemented if device features both a Memory Protection Unit (MPU) and an XGATE co-processor 3 only implemented if device features a Memory Protection Unit (MPU) S12XS-Family Reference Manual, Rev. 1.03 158 PRELIMINARY Freescale Semiconductor 4.5 Initialization/Application Information Interrupt (S12XINTV2) 4.5.1 Initialization After system reset, software should: • Initialize the interrupt vector base register if the interrupt vector table is not located at the default location (0xFF10–0xFFF9). • Initialize the interrupt processing level configuration data registers (INT_CFADDR, INT_CFDATA0–7) for all interrupt vector requests with the desired priority levels and the request target (CPU or XGATE module). It might be a good idea to disable unused interrupt requests. • If the XGATE module is used, setup the XGATE interrupt priority register (INT_XGPRIO) and configure the XGATE module (please refer the XGATE Block Guide for details). • Enable I maskable interrupts by clearing the I bit in the CCR. • Enable the X maskable interrupt by clearing the X bit in the CCR (if required). 4.5.2 Interrupt Nesting The interrupt request priority level scheme makes it possible to implement priority based interrupt request nesting for the I bit maskable interrupt requests handled by the CPU. • I bit maskable interrupt requests can be interrupted by an interrupt request with a higher priority, so that there can be up to seven nested I bit maskable interrupt requests at a time (refer to Figure 414 for an example using up to three nested interrupt requests). I bit maskable interrupt requests cannot be interrupted by other I bit maskable interrupt requests per default. In order to make an interrupt service routine (ISR) interruptible, the ISR must explicitly clear the I bit in the CCR (CLI). After clearing the I bit, I bit maskable interrupt requests with higher priority can interrupt the current ISR. An ISR of an interruptible I bit maskable interrupt request could basically look like this: • Service interrupt, e.g., clear interrupt flags, copy data, etc. • Clear I bit in the CCR by executing the instruction CLI (thus allowing interrupt requests with higher priority) • Process data • Return from interrupt by executing the instruction RTI S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 159 Interrupt (S12XINTV2) Stacked IPL 0 0 4 0 0 0 IPL in CCR Processing Levels 0 4 7 4 3 7 6 L7 RTI 5 4 3 2 L4 RTI L3 (Pending) 1 L1 (Pending) 0 Reset Figure 4-14. Interrupt Processing Example 1 RTI 0 RTI 4.5.3 Wake Up from Stop or Wait Mode 4.5.3.1 CPU Wake Up from Stop or Wait Mode Every I bit maskable interrupt request which is configured to be handled by the CPU is capable of waking the MCU from stop or wait mode. To determine whether an I bit maskable interrupts is qualified to wake up the CPU or not, the same settings as in normal run mode are applied during stop or wait mode: • If the I bit in the CCR is set, all I bit maskable interrupts are masked from waking up the MCU. • An I bit maskable interrupt is ignored if it is configured to a priority level below or equal to the current IPL in CCR. • I bit maskable interrupt requests which are configured to be handled by the XGATE module are not capable of waking up the CPU. The X bit maskable interrupt request can wake up the MCU from stop or wait mode at anytime, even if the X bit in CCR is set. If the X bit maskable interrupt request is used to wake-up the MCU with the X bit in the CCR set, the associated ISR is not called. The CPU then resumes program execution with the instruction following the WAI or STOP instruction. This features works following the same rules like any interrupt request, i.e. care must be taken that the X interrupt request used for wake-up remains active at least until the system begins execution of the instruction following the WAI or STOP instruction; otherwise, wake-up may not occur. 4.5.3.2 XGATE Wake Up from Stop or Wait Mode Interrupt request channels which are configured to be handled by the XGATE module are capable of waking up the XGATE module. Interrupt request channels handled by the XGATE module do not affect the state of the CPU. S12XS-Family Reference Manual, Rev. 1.03 160 PRELIMINARY Freescale Semiconductor Chapter 5 Background Debug Module (S12XBDMV2) Table 5-1. Revision History Revision Number V02.00 V02.01 Revision Date 07 Mar 2006 14 May 2008 Sections Affected Description of Changes - First version of S12XBDMV2 - Introduced standardized Revision History Table 5.1 Introduction This section describes the functionality of the background debug module (BDM) sub-block of the HCS12X core platform. The background debug module (BDM) sub-block is a single-wire, background debug system implemented in on-chip hardware for minimal CPU intervention. All interfacing with the BDM is done via the BKGD pin. The BDM has enhanced capability for maintaining synchronization between the target and host while allowing more flexibility in clock rates. This includes a sync signal to determine the communication rate and a handshake signal to indicate when an operation is complete. The system is backwards compatible to the BDM of the S12 family with the following exceptions: • TAGGO command no longer supported by BDM • External instruction tagging feature now part of DBG module • BDM register map and register content extended/modified • Global page access functionality • Enabled but not active out of reset in emulation modes (if modes available) • CLKSW bit set out of reset in emulation modes (if modes available). • Family ID readable from firmware ROM at global address 0x7FFF0F (value for HCS12X devices is 0xC1) 5.1.1 Features The BDM includes these distinctive features: • Single-wire communication with host development system • Enhanced capability for allowing more flexibility in clock rates • SYNC command to determine communication rate • GO_UNTIL command • Hardware handshake protocol to increase the performance of the serial communication S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 161 Background Debug Module (S12XBDMV2) • Active out of reset in special single chip mode • Nine hardware commands using free cycles, if available, for minimal CPU intervention • Hardware commands not requiring active BDM • 14 firmware commands execute from the standard BDM firmware lookup table • Software control of BDM operation during wait mode • Software selectable clocks • Global page access functionality • Enabled but not active out of reset in emulation modes (if modes available) • CLKSW bit set out of reset in emulation modes (if modes available). • When secured, hardware commands are allowed to access the register space in special single chip mode, if the non-volatile memory erase test fail. • Family ID readable from firmware ROM at global address 0x7FFF0F (value for HCS12X devices is 0xC1) • BDM hardware commands are operational until system stop mode is entered (all bus masters are in stop mode) 5.1.2 Modes of Operation BDM is available in all operating modes but must be enabled before firmware commands are executed. Some systems may have a control bit that allows suspending thefunction during background debug mode. 5.1.2.1 Regular Run Modes All of these operations refer to the part in run mode and not being secured. The BDM does not provide controls to conserve power during run mode. • Normal modes General operation of the BDM is available and operates the same in all normal modes. • Special single chip mode In special single chip mode, background operation is enabled and active out of reset. This allows programming a system with blank memory. • Emulation modes (if modes available) In emulation mode, background operation is enabled but not active out of reset. This allows debugging and programming a system in this mode more easily. 5.1.2.2 Secure Mode Operation If the device is in secure mode, the operation of the BDM is reduced to a small subset of its regular run mode operation. Secure operation prevents BDM and CPU accesses to non-volatile memory (Flash and/or EEPROM) other than allowing erasure. For more information please see Section 5.4.1, “Security”. S12XS-Family Reference Manual, Rev. 1.03 162 PRELIMINARY Freescale Semiconductor Background Debug Module (S12XBDMV2) 5.1.2.3 Low-Power Modes The BDM can be used until all bus masters (e.g., CPU or XGATE or others depending on which masters are available on the SOC) are in stop mode. When CPU is in a low power mode (wait or stop mode) all BDM firmware commands as well as the hardware BACKGROUND command can not be used respectively are ignored. In this case the CPU can not enter BDM active mode, and only hardware read and write commands are available. Also the CPU can not enter a low power mode during BDM active mode. If all bus masters are in stop mode, the BDM clocks are stopped as well. When BDM clocks are disabled and one of the bus masters exits from stop mode the BDM clocks will restart and BDM will have a soft reset (clearing the instruction register, any command in progress and disable the ACK function). The BDM is now ready to receive a new command. 5.1.3 Block Diagram A block diagram of the BDM is shown in Figure 5-1. Host System BKGD Serial Interface Register Block Data Control 16-Bit Shift Register TRACE BDMACT Instruction Code and Execution Bus Interface and Control Logic Address Data Control Clocks ENBDM SDV UNSEC CLKSW BDMSTS Register Standard BDM Firmware LOOKUP TABLE Secured BDM Firmware LOOKUP TABLE Figure 5-1. BDM Block Diagram 5.2 External Signal Description A single-wire interface pin called the background debug interface (BKGD) pin is used to communicate with the BDM system. During reset, this pin is a mode select input which selects between normal and special modes of operation. After reset, this pin becomes the dedicated serial interface pin for the background debug mode. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 163 Background Debug Module (S12XBDMV2) 5.3 Memory Map and Register Definition 5.3.1 Module Memory Map Table 5-2 shows the BDM memory map when BDM is active. Table 5-2. BDM Memory Map Global Address 0x7FFF00–0x7FFF0B 0x7FFF0C–0x7FFF0E 0x7FFF0F 0x7FFF10–0x7FFFFF Module BDM registers BDM firmware ROM Family ID (part of BDM firmware ROM) BDM firmware ROM Size (Bytes) 12 3 1 240 5.3.2 Register Descriptions A summary of the registers associated with the BDM is shown in Figure 5-2. Registers are accessed by host-driven communications to the BDM hardware using READ_BD and WRITE_BD commands. Global Register Address Name Bit 7 6 5 4 3 2 1 Bit 0 0x7FFF00 Reserved R X X X X X X 0 0 W 0x7FFF01 BDMSTS R BDMACT 0 ENBDM W SDV TRACE UNSEC 0 CLKSW 0x7FFF02 Reserved R X X X X X X X X W 0x7FFF03 Reserved R X X X X X X X X W 0x7FFF04 Reserved R X X X X X X X X W 0x7FFF05 Reserved R X X X X X X X X W 0x7FFF06 BDMCCRL R CCR7 W CCR6 CCR5 CCR4 CCR3 CCR2 CCR1 CCR0 = Unimplemented, Reserved = Implemented (do not alter) X = Indeterminate 0 Figure 5-2. BDM Register Summary = Always read zero S12XS-Family Reference Manual, Rev. 1.03 164 PRELIMINARY Freescale Semiconductor Background Debug Module (S12XBDMV2) Global Register Address Name 0x7FFF07 BDMCCRH R W Bit 7 0 0x7FFF08 BDMGPR R BGAE W 0x7FFF09 Reserved R 0 W 0x7FFF0A Reserved R 0 W 0x7FFF0B Reserved R 0 W 6 0 BGP6 0 0 0 5 0 BGP5 0 0 0 4 0 BGP4 0 0 0 3 2 1 0 CCR10 CCR9 BGP3 BGP2 BGP1 0 0 0 0 0 0 0 0 0 Bit 0 CCR8 BGP0 0 0 0 = Unimplemented, Reserved = Implemented (do not alter) X = Indeterminate 0 = Always read zero Figure 5-2. BDM Register Summary (continued) 5.3.2.1 BDM Status Register (BDMSTS) Register Global Address 0x7FFF01 R W Reset Special Single-Chip Mode Emulation Modes (if modes available) All Other Modes 7 ENBDM 01 1 0 6 5 BDMACT 0 4 SDV 1 0 0 0 0 0 0 0 0 = Unimplemented, Reserved 3 2 1 0 TRACE UNSEC 0 CLKSW 0 0 03 0 0 12 0 0 0 0 0 0 = Implemented (do not alter) 0 = Always read zero 1 ENBDM is read as 1 by a debugging environment in special single chip mode when the device is not secured or secured but fully erased (non-volatile memory). This is because the ENBDM bit is set by the standard firmware before a BDM command can be fully transmitted and executed. 2 CLKSW is read as 1 by a debugging environment in emulation modes when the device is not secured and read as 0 when secured if emulation modes available. 3 UNSEC is read as 1 by a debugging environment in special single chip mode when the device is secured and fully erased, else it is 0 and can only be read if not secure (see also bit description). Figure 5-3. BDM Status Register (BDMSTS) S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 165 Background Debug Module (S12XBDMV2) Read: All modes through BDM operation when not secured Write: All modes through BDM operation when not secured, but subject to the following: — ENBDM should only be set via a BDM hardware command if the BDM firmware commands are needed. (This does not apply in special single chip and emulation modes). — BDMACT can only be set by BDM hardware upon entry into BDM. It can only be cleared by the standard BDM firmware lookup table upon exit from BDM active mode. — CLKSW can only be written via BDM hardware WRITE_BD commands. — All other bits, while writable via BDM hardware or standard BDM firmware write commands, should only be altered by the BDM hardware or standard firmware lookup table as part of BDM command execution. Table 5-3. BDMSTS Field Descriptions Field Description 7 ENBDM 6 BDMACT 4 SDV 3 TRACE Enable BDM — This bit controls whether the BDM is enabled or disabled. When enabled, BDM can be made active to allow firmware commands to be executed. When disabled, BDM cannot be made active but BDM hardware commands are still allowed. 0 BDM disabled 1 BDM enabled Note: ENBDM is set by the firmware out of reset in special single chip mode. In emulation modes (if modes available) the ENBDM bit is set by BDM hardware out of reset. In special single chip mode with the device secured, this bit will not be set by the firmware until after the non-volatile memory erase verify tests are complete. In emulation modes (if modes available) with the device secured, the BDM operations are blocked. BDM Active Status — This bit becomes set upon entering BDM. The standard BDM firmware lookup table is then enabled and put into the memory map. BDMACT is cleared by a carefully timed store instruction in the standard BDM firmware as part of the exit sequence to return to user code and remove the BDM memory from the map. 0 BDM not active 1 BDM active Shift Data Valid — This bit is set and cleared by the BDM hardware. It is set after data has been transmitted as part of a firmware or hardware read command or after data has been received as part of a firmware or hardware write command. It is cleared when the next BDM command has been received or BDM is exited. SDV is used by the standard BDM firmware to control program flow execution. 0 Data phase of command not complete 1 Data phase of command is complete TRACE1 BDM Firmware Command is Being Executed — This bit gets set when a BDM TRACE1 firmware command is first recognized. It will stay set until BDM firmware is exited by one of the following BDM commands: GO or GO_UNTIL. 0 TRACE1 command is not being executed 1 TRACE1 command is being executed S12XS-Family Reference Manual, Rev. 1.03 166 PRELIMINARY Freescale Semiconductor Background Debug Module (S12XBDMV2) Table 5-3. BDMSTS Field Descriptions (continued) Field 2 CLKSW 1 UNSEC Description Clock Switch — The CLKSW bit controls which clock the BDM operates with. It is only writable from a hardware BDM command. A minimum delay of 150 cycles at the clock speed that is active during the data portion of the command send to change the clock source should occur before the next command can be send. The delay should be obtained no matter which bit is modified to effectively change the clock source (either PLLSEL bit or CLKSW bit). This guarantees that the start of the next BDM command uses the new clock for timing subsequent BDM communications. Table 5-4 shows the resulting BDM clock source based on the CLKSW and the PLLSEL (PLL select in the CRG module, the bit is part of the CLKSEL register) bits. Note: The BDM alternate clock source can only be selected when CLKSW = 0 and PLLSEL = 1. The BDM serial interface is now fully synchronized to the alternate clock source, when enabled. This eliminates frequency restriction on the alternate clock which was required on previous versions. Refer to the device specification to determine which clock connects to the alternate clock source input. Note: If the acknowledge function is turned on, changing the CLKSW bit will cause the ACK to be at the new rate for the write command which changes it. Note: In emulation modes (if modes available), the CLKSW bit will be set out of RESET. Unsecure — If the device is secured this bit is only writable in special single chip mode from the BDM secure firmware. It is in a zero state as secure mode is entered so that the secure BDM firmware lookup table is enabled and put into the memory map overlapping the standard BDM firmware lookup table. The secure BDM firmware lookup table verifies that the non-volatile memories (e.g. on-chip EEPROM and/or Flash EEPROM) are erased. This being the case, the UNSEC bit is set and the BDM program jumps to the start of the standard BDM firmware lookup table and the secure BDM firmware lookup table is turned off. If the erase test fails, the UNSEC bit will not be asserted. 0 System is in a secured mode. 1 System is in a unsecured mode. Note: When UNSEC is set, security is off and the user can change the state of the secure bits in the on-chip Flash EEPROM. Note that if the user does not change the state of the bits to “unsecured” mode, the system will be secured again when it is next taken out of reset.After reset this bit has no meaning or effect when the security byte in the Flash EEPROM is configured for unsecure mode. Table 5-4. BDM Clock Sources PLLSEL CLKSW BDMCLK 0 0 Bus clock dependent on oscillator 0 1 Bus clock dependent on oscillator 1 0 Alternate clock (refer to the device specification to determine the alternate clock source) 1 1 Bus clock dependent on the PLL S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 167 Background Debug Module (S12XBDMV2) 5.3.2.2 BDM CCR LOW Holding Register (BDMCCRL) Register Global Address 0x7FFF06 R W Reset Special Single-Chip Mode All Other Modes 7 CCR7 1 0 6 CCR6 1 0 5 CCR5 0 0 4 CCR4 0 0 3 CCR3 1 0 2 CCR2 0 0 1 CCR1 0 0 0 CCR0 0 0 Figure 5-4. BDM CCR LOW Holding Register (BDMCCRL) Read: All modes through BDM operation when not secured Write: All modes through BDM operation when not secured NOTE When BDM is made active, the CPU stores the content of its CCRL register in the BDMCCRL register. However, out of special single-chip reset, the BDMCCRL is set to 0xD8 and not 0xD0 which is the reset value of the CCRL register in this CPU mode. Out of reset in all other modes the BDMCCRL register is read zero. When entering background debug mode, the BDM CCR LOW holding register is used to save the low byte of the condition code register of the user’s program. It is also used for temporary storage in the standard BDM firmware mode. The BDM CCR LOW holding register can be written to modify the CCR value. 5.3.2.3 BDM CCR HIGH Holding Register (BDMCCRH) Register Global Address 0x7FFF07 7 6 5 4 R 0 0 0 0 W Reset 0 0 0 0 = Unimplemented or Reserved 3 2 1 0 0 CCR10 CCR9 CCR8 0 0 0 0 Figure 5-5. BDM CCR HIGH Holding Register (BDMCCRH) Read: All modes through BDM operation when not secured Write: All modes through BDM operation when not secured When entering background debug mode, the BDM CCR HIGH holding register is used to save the high byte of the condition code register of the user’s program. The BDM CCR HIGH holding register can be written to modify the CCR value. S12XS-Family Reference Manual, Rev. 1.03 168 PRELIMINARY Freescale Semiconductor 5.3.2.4 Background Debug Module (S12XBDMV2) BDM Global Page Index Register (BDMGPR) Register Global Address 0x7FFF08 7 6 R W Reset BGAE 0 BGP6 0 5 BGP5 0 4 BGP4 0 3 BGP3 0 2 BGP2 0 Figure 5-6. BDM Global Page Register (BDMGPR) 1 BGP1 0 0 BGP0 0 Read: All modes through BDM operation when not secured Write: All modes through BDM operation when not secured Table 5-5. BDMGPR Field Descriptions Field 7 BGAE 6–0 BGP[6:0] Description BDM Global Page Access Enable Bit — BGAE enables global page access for BDM hardware and firmware read/write instructions The BDM hardware commands used to access the BDM registers (READ_BD_ and WRITE_BD_) can not be used for global accesses even if the BGAE bit is set. 0 BDM Global Access disabled 1 BDM Global Access enabled BDM Global Page Index Bits 6–0 — These bits define the extended address bits from 22 to 16. For more detailed information regarding the global page window scheme, please refer to the S12X_MMC Block Guide. 5.3.3 Family ID Assignment The family ID is a 8-bit value located in the firmware ROM (at global address: 0x7FFF0F). The read-only value is a unique family ID which is 0xC1 for S12X devices. 5.4 Functional Description The BDM receives and executes commands from a host via a single wire serial interface. There are two types of BDM commands: hardware and firmware commands. Hardware commands are used to read and write target system memory locations and to enter active background debug mode, see Section 5.4.3, “BDM Hardware Commands”. Target system memory includes all memory that is accessible by the CPU. Firmware commands are used to read and write CPU resources and to exit from active background debug mode, see Section 5.4.4, “Standard BDM Firmware Commands”. The CPU resources referred to are the accumulator (D), X index register (X), Y index register (Y), stack pointer (SP), and program counter (PC). Hardware commands can be executed at any time and in any mode excluding a few exceptions as highlighted (see Section 5.4.3, “BDM Hardware Commands”) and in secure mode (see Section 5.4.1, “Security”). Firmware commands can only be executed when the system is not secure and is in active background debug mode (BDM). S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 169 Background Debug Module (S12XBDMV2) 5.4.1 Security If the user resets into special single chip mode with the system secured, a secured mode BDM firmware lookup table is brought into the map overlapping a portion of the standard BDM firmware lookup table. The secure BDM firmware verifies that the on-chip non-volatile memory (e.g. EEPROM and Flash EEPROM) is erased. This being the case, the UNSEC and ENBDM bit will get set. The BDM program jumps to the start of the standard BDM firmware and the secured mode BDM firmware is turned off and all BDM commands are allowed. If the non-volatile memory does not verify as erased, the BDM firmware sets the ENBDM bit, without asserting UNSEC, and the firmware enters a loop. This causes the BDM hardware commands to become enabled, but does not enable the firmware commands. This allows the BDM hardware to be used to erase the non-volatile memory. BDM operation is not possible in any other mode than special single chip mode when the device is secured. The device can be unsecured via BDM serial interface in special single chip mode only. For more information regarding security, please see the S12X_9SEC Block Guide. 5.4.2 Enabling and Activating BDM The system must be in active BDM to execute standard BDM firmware commands. BDM can be activated only after being enabled. BDM is enabled by setting the ENBDM bit in the BDM status (BDMSTS) register. The ENBDM bit is set by writing to the BDM status (BDMSTS) register, via the single-wire interface, using a hardware command such as WRITE_BD_BYTE. After being enabled, BDM is activated by one of the following1: • Hardware BACKGROUND command • CPU BGND instruction • External instruction tagging mechanism2 • Breakpoint force or tag mechanism2 When BDM is activated, the CPU finishes executing the current instruction and then begins executing the firmware in the standard BDM firmware lookup table. When BDM is activated by a breakpoint, the type of breakpoint used determines if BDM becomes active before or after execution of the next instruction. NOTE If an attempt is made to activate BDM before being enabled, the CPU resumes normal instruction execution after a brief delay. If BDM is not enabled, any hardware BACKGROUND commands issued are ignored by the BDM and the CPU is not delayed. In active BDM, the BDM registers and standard BDM firmware lookup table are mapped to addresses 0x7FFF00 to 0x7FFFFF. BDM registers are mapped to addresses 0x7FFF00 to 0x7FFF0B. The BDM uses these registers which are readable anytime by the BDM. However, these registers are not readable by user programs. 1. BDM is enabled and active immediately out of special single-chip reset. 2. This method is provided by the S12X_DBG module. S12XS-Family Reference Manual, Rev. 1.03 170 PRELIMINARY Freescale Semiconductor Background Debug Module (S12XBDMV2) 5.4.3 BDM Hardware Commands Hardware commands are used to read and write target system memory locations and to enter active background debug mode. Target system memory includes all memory that is accessible by the CPU on the SOC which can be on-chip RAM, non-volatile memory (e.g. EEPROM, Flash EEPROM), I/O and control registers, and all external memory. Hardware commands are executed with minimal or no CPU intervention and do not require the system to be in active BDM for execution, although, they can still be executed in this mode. When executing a hardware command, the BDM sub-block waits for a free bus cycle so that the background access does not disturb the running application program. If a free cycle is not found within 128 clock cycles, the CPU is momentarily frozen so that the BDM can steal a cycle. When the BDM finds a free cycle, the operation does not intrude on normal CPU operation provided that it can be completed in a single cycle. However, if an operation requires multiple cycles the CPU is frozen until the operation is complete, even though the BDM found a free cycle. The BDM hardware commands are listed in Table 5-6. The READ_BD and WRITE_BD commands allow access to the BDM register locations. These locations are not normally in the system memory map but share addresses with the application in memory. To distinguish between physical memory locations that share the same address, BDM memory resources are enabled just for the READ_BD and WRITE_BD access cycle. This allows the BDM to access BDM locations unobtrusively, even if the addresses conflict with the application memory map. Table 5-6. Hardware Commands Command Opcode (hex) Data Description BACKGROUND 90 None Enter background mode if firmware is enabled. If enabled, an ACK will be issued when the part enters active background mode. ACK_ENABLE D5 None Enable Handshake. Issues an ACK pulse after the command is executed. ACK_DISABLE D6 None Disable Handshake. This command does not issue an ACK pulse. READ_BD_BYTE E4 16-bit address Read from memory with standard BDM firmware lookup table in map. 16-bit data out Odd address data on low byte; even address data on high byte. READ_BD_WORD EC 16-bit address Read from memory with standard BDM firmware lookup table in map. 16-bit data out Must be aligned access. READ_BYTE E0 16-bit address Read from memory with standard BDM firmware lookup table out of map. 16-bit data out Odd address data on low byte; even address data on high byte. READ_WORD E8 16-bit address Read from memory with standard BDM firmware lookup table out of map. 16-bit data out Must be aligned access. WRITE_BD_BYTE C4 16-bit address Write to memory with standard BDM firmware lookup table in map. 16-bit data in Odd address data on low byte; even address data on high byte. WRITE_BD_WORD CC 16-bit address Write to memory with standard BDM firmware lookup table in map. 16-bit data in Must be aligned access. WRITE_BYTE C0 16-bit address Write to memory with standard BDM firmware lookup table out of map. 16-bit data in Odd address data on low byte; even address data on high byte. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 171 Background Debug Module (S12XBDMV2) Table 5-6. Hardware Commands (continued) Command Opcode (hex) Data Description WRITE_WORD C8 16-bit address Write to memory with standard BDM firmware lookup table out of map. 16-bit data in Must be aligned access. NOTE: If enabled, ACK will occur when data is ready for transmission for all BDM READ commands and will occur after the write is complete for all BDM WRITE commands. 5.4.4 Standard BDM Firmware Commands Firmware commands are used to access and manipulate CPU resources. The system must be in active BDM to execute standard BDM firmware commands, see Section 5.4.2, “Enabling and Activating BDM”. Normal instruction execution is suspended while the CPU executes the firmware located in the standard BDM firmware lookup table. The hardware command BACKGROUND is the usual way to activate BDM. As the system enters active BDM, the standard BDM firmware lookup table and BDM registers become visible in the on-chip memory map at 0x7FFF00–0x7FFFFF, and the CPU begins executing the standard BDM firmware. The standard BDM firmware watches for serial commands and executes them as they are received. The firmware commands are shown in Table 5-7. S12XS-Family Reference Manual, Rev. 1.03 172 PRELIMINARY Freescale Semiconductor Background Debug Module (S12XBDMV2) Table 5-7. Firmware Commands Command1 Opcode (hex) Data Description READ_NEXT2 62 16-bit data out Increment X index register by 2 (X = X + 2), then read word X points to. READ_PC 63 16-bit data out Read program counter. READ_D 64 16-bit data out Read D accumulator. READ_X 65 16-bit data out Read X index register. READ_Y 66 16-bit data out Read Y index register. READ_SP 67 16-bit data out Read stack pointer. WRITE_NEXT 42 16-bit data in Increment X index register by 2 (X = X + 2), then write word to location pointed to by X. WRITE_PC 43 16-bit data in Write program counter. WRITE_D 44 16-bit data in Write D accumulator. WRITE_X 45 16-bit data in Write X index register. WRITE_Y 46 16-bit data in Write Y index register. WRITE_SP 47 16-bit data in Write stack pointer. GO GO_UNTIL3 08 none Go to user program. If enabled, ACK will occur when leaving active background mode. 0C none Go to user program. If enabled, ACK will occur upon returning to active background mode. TRACE1 10 none Execute one user instruction then return to active BDM. If enabled, ACK will occur upon returning to active background mode. TAGGO -> GO 18 none (Previous enable tagging and go to user program.) This command will be deprecated and should not be used anymore. Opcode will be executed as a GO command. 1 If enabled, ACK will occur when data is ready for transmission for all BDM READ commands and will occur after the write is complete for all BDM WRITE commands. 2 When the firmware command READ_NEXT or WRITE_NEXT is used to access the BDM address space the BDM resources are accessed rather than user code. Writing BDM firmware is not possible. 3 System stop disables the ACK function and ignored commands will not have an ACK-pulse (e.g., CPU in stop or wait mode). The GO_UNTIL command will not get an Acknowledge if CPU executes the wait or stop instruction before the “UNTIL” condition (BDM active again) is reached (see Section 5.4.7, “Serial Interface Hardware Handshake Protocol” last Note). 5.4.5 BDM Command Structure Hardware and firmware BDM commands start with an 8-bit opcode followed by a 16-bit address and/or a 16-bit data word depending on the command. All the read commands return 16 bits of data despite the byte or word implication in the command name. 8-bit reads return 16-bits of data, of which, only one byte will contain valid data. If reading an even address, the valid data will appear in the MSB. If reading an odd address, the valid data will appear in the LSB. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 173 Background Debug Module (S12XBDMV2) 16-bit misaligned reads and writes are generally not allowed. If attempted by BDM hardware command, the BDM will ignore the least significant bit of the address and will assume an even address from the remaining bits. For devices with external bus: The following cycle count information is only valid when the external wait function is not used (see wait bit of EBI sub-block). During an external wait the BDM can not steal a cycle. Hence be careful with the external wait function if the BDM serial interface is much faster than the bus, because of the BDM soft-reset after time-out (see Section 5.4.11, “Serial Communication Time Out”). For hardware data read commands, the external host must wait at least 150 bus clock cycles after sending the address before attempting to obtain the read data. This is to be certain that valid data is available in the BDM shift register, ready to be shifted out. For hardware write commands, the external host must wait 150 bus clock cycles after sending the data to be written before attempting to send a new command. This is to avoid disturbing the BDM shift register before the write has been completed. The 150 bus clock cycle delay in both cases includes the maximum 128 cycle delay that can be incurred as the BDM waits for a free cycle before stealing a cycle. For firmware read commands, the external host should wait at least 48 bus clock cycles after sending the command opcode and before attempting to obtain the read data. This includes the potential of extra cycles when the access is external and stretched (+1 to maximum +7 cycles) or to registers of the PRU (port replacement unit) in emulation modes (if modes available). The 48 cycle wait allows enough time for the requested data to be made available in the BDM shift register, ready to be shifted out. NOTE This timing has increased from previous BDM modules due to the new capability in which the BDM serial interface can potentially run faster than the bus. On previous BDM modules this extra time could be hidden within the serial time. For firmware write commands, the external host must wait 36 bus clock cycles after sending the data to be written before attempting to send a new command. This is to avoid disturbing the BDM shift register before the write has been completed. The external host should wait at least for 76 bus clock cycles after a TRACE1 or GO command before starting any new serial command. This is to allow the CPU to exit gracefully from the standard BDM firmware lookup table and resume execution of the user code. Disturbing the BDM shift register prematurely may adversely affect the exit from the standard BDM firmware lookup table. NOTE If the bus rate of the target processor is unknown or could be changing or the external wait function is used, it is recommended that the ACK (acknowledge function) is used to indicate when an operation is complete. When using ACK, the delay times are automated. S12XS-Family Reference Manual, Rev. 1.03 174 PRELIMINARY Freescale Semiconductor Background Debug Module (S12XBDMV2) Figure 5-7 represents the BDM command structure. The command blocks illustrate a series of eight bit times starting with a falling edge. The bar across the top of the blocks indicates that the BKGD line idles in the high state. The time for an 8-bit command is 8 × 16 target clock cycles.1 Hardware Read Hardware Write Firmware Read Firmware Write GO, TRACE 8 Bits AT ~16 TC/Bit Command 16 Bits AT ~16 TC/Bit Address 150-BC Delay 16 Bits AT ~16 TC/Bit Data Next Command Command Address 150-BC Delay Data Next Command 48-BC DELAY Command Data Next Command Command 36-BC DELAY Data Next Command Command 76-BC Delay Next Command Figure 5-7. BDM Command Structure BC = Bus Clock Cycles TC = Target Clock Cycles 5.4.6 BDM Serial Interface The BDM communicates with external devices serially via the BKGD pin. During reset, this pin is a mode select input which selects between normal and special modes of operation. After reset, this pin becomes the dedicated serial interface pin for the BDM. The BDM serial interface is timed using the clock selected by the CLKSW bit in the status register see Section 5.3.2.1, “BDM Status Register (BDMSTS)”. This clock will be referred to as the target clock in the following explanation. The BDM serial interface uses a clocking scheme in which the external host generates a falling edge on the BKGD pin to indicate the start of each bit time. This falling edge is sent for every bit whether data is transmitted or received. Data is transferred most significant bit (MSB) first at 16 target clock cycles per bit. The interface times out if 512 clock cycles occur between falling edges from the host. The BKGD pin is a pseudo open-drain pin and has an weak on-chip active pull-up that is enabled at all times. It is assumed that there is an external pull-up and that drivers connected to BKGD do not typically drive the high level. Since R-C rise time could be unacceptably long, the target system and host provide brief driven-high (speedup) pulses to drive BKGD to a logic 1. The source of this speedup pulse is the host for transmit cases and the target for receive cases. 1. Target clock cycles are cycles measured using the target MCU’s serial clock rate. See Section 5.4.6, “BDM Serial Interface” and Section 5.3.2.1, “BDM Status Register (BDMSTS)” for information on how serial clock rate is selected. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 175 Background Debug Module (S12XBDMV2) The timing for host-to-target is shown in Figure 5-8 and that of target-to-host in Figure 5-9 and Figure 5-10. All four cases begin when the host drives the BKGD pin low to generate a falling edge. Since the host and target are operating from separate clocks, it can take the target system up to one full clock cycle to recognize this edge. The target measures delays from this perceived start of the bit time while the host measures delays from the point it actually drove BKGD low to start the bit up to one target clock cycle earlier. Synchronization between the host and target is established in this manner at the start of every bit time. Figure 5-8 shows an external host transmitting a logic 1 and transmitting a logic 0 to the BKGD pin of a target system. The host is asynchronous to the target, so there is up to a one clock-cycle delay from the host-generated falling edge to where the target recognizes this edge as the beginning of the bit time. Ten target clock cycles later, the target senses the bit level on the BKGD pin. Internal glitch detect logic requires the pin be driven high no later that eight target clock cycles after the falling edge for a logic 1 transmission. Since the host drives the high speedup pulses in these two cases, the rising edges look like digitally driven signals. BDM Clock (Target MCU) Host Transmit 1 Host Transmit 0 Perceived Start of Bit Time Target Senses Bit 10 Cycles Synchronization Uncertainty Figure 5-8. BDM Host-to-Target Serial Bit Timing Earliest Start of Next Bit The receive cases are more complicated. Figure 5-9 shows the host receiving a logic 1 from the target system. Since the host is asynchronous to the target, there is up to one clock-cycle delay from the hostgenerated falling edge on BKGD to the perceived start of the bit time in the target. The host holds the BKGD pin low long enough for the target to recognize it (at least two target clock cycles). The host must release the low drive before the target drives a brief high speedup pulse seven target clock cycles after the perceived start of the bit time. The host should sample the bit level about 10 target clock cycles after it started the bit time. S12XS-Family Reference Manual, Rev. 1.03 176 PRELIMINARY Freescale Semiconductor BDM Clock (Target MCU) Host Drive to BKGD Pin Target System Speedup Pulse Perceived Start of Bit Time BKGD Pin Background Debug Module (S12XBDMV2) High-Impedance High-Impedance R-C Rise High-Impedance 10 Cycles 10 Cycles Host Samples BKGD Pin Figure 5-9. BDM Target-to-Host Serial Bit Timing (Logic 1) Earliest Start of Next Bit S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 177 Background Debug Module (S12XBDMV2) Figure 5-10 shows the host receiving a logic 0 from the target. Since the host is asynchronous to the target, there is up to a one clock-cycle delay from the host-generated falling edge on BKGD to the start of the bit time as perceived by the target. The host initiates the bit time but the target finishes it. Since the target wants the host to receive a logic 0, it drives the BKGD pin low for 13 target clock cycles then briefly drives it high to speed up the rising edge. The host samples the bit level about 10 target clock cycles after starting the bit time. BDM Clock (Target MCU) Host Drive to BKGD Pin Target System Drive and Speedup Pulse Perceived Start of Bit Time BKGD Pin High-Impedance Speedup Pulse 10 Cycles 10 Cycles Host Samples BKGD Pin Figure 5-10. BDM Target-to-Host Serial Bit Timing (Logic 0) Earliest Start of Next Bit 5.4.7 Serial Interface Hardware Handshake Protocol BDM commands that require CPU execution are ultimately treated at the MCU bus rate. Since the BDM clock source can be asynchronously related to the bus frequency, when CLKSW = 0, it is very helpful to provide a handshake protocol in which the host could determine when an issued command is executed by the CPU. The alternative is to always wait the amount of time equal to the appropriate number of cycles at the slowest possible rate the clock could be running. This sub-section will describe the hardware handshake protocol. The hardware handshake protocol signals to the host controller when an issued command was successfully executed by the target. This protocol is implemented by a 16 serial clock cycle low pulse followed by a brief speedup pulse in the BKGD pin. This pulse is generated by the target MCU when a command, issued by the host, has been successfully executed (see Figure 5-11). This pulse is referred to as the ACK pulse. After the ACK pulse has finished: the host can start the bit retrieval if the last issued command was a read command, or start a new command if the last command was a write command or a control command (BACKGROUND, GO, GO_UNTIL or TRACE1). The ACK pulse is not issued earlier than 32 serial clock cycles after the BDM command was issued. The end of the BDM command is assumed to be the 16th tick of the last bit. This minimum delay assures enough time for the host to perceive the ACK pulse. Note also that, there is no upper limit for the delay between the command and the related ACK pulse, since the command execution depends upon the CPU bus frequency, which in some cases could be very slow S12XS-Family Reference Manual, Rev. 1.03 178 PRELIMINARY Freescale Semiconductor Background Debug Module (S12XBDMV2) compared to the serial communication rate. This protocol allows a great flexibility for the POD designers, since it does not rely on any accurate time measurement or short response time to any event in the serial communication. BDM Clock (Target MCU) Target Transmits ACK Pulse BKGD Pin High-Impedance 16 Cycles 32 Cycles Speedup Pulse Minimum Delay From the BDM Command High-Impedance 16th Tick of the Last Command Bit Figure 5-11. Target Acknowledge Pulse (ACK) Earliest Start of Next Bit NOTE If the ACK pulse was issued by the target, the host assumes the previous command was executed. If the CPU enters wait or stop prior to executing a hardware command, the ACK pulse will not be issued meaning that the BDM command was not executed. After entering wait or stop mode, the BDM command is no longer pending. Figure 5-12 shows the ACK handshake protocol in a command level timing diagram. The READ_BYTE instruction is used as an example. First, the 8-bit instruction opcode is sent by the host, followed by the address of the memory location to be read. The target BDM decodes the instruction. A bus cycle is grabbed (free or stolen) by the BDM and it executes the READ_BYTE operation. Having retrieved the data, the BDM issues an ACK pulse to the host controller, indicating that the addressed byte is ready to be retrieved. After detecting the ACK pulse, the host initiates the byte retrieval process. Note that data is sent in the form of a word and the host needs to determine which is the appropriate byte based on whether the address was odd or even. Target Host BKGD Pin READ_BYTE Byte Address Host Target (2) Bytes are Retrieved New BDM Command Host Target BDM Issues the ACK Pulse (out of scale) BDM Decodes the Command BDM Executes the READ_BYTE Command Figure 5-12. Handshake Protocol at Command Level S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 179 Background Debug Module (S12XBDMV2) Differently from the normal bit transfer (where the host initiates the transmission), the serial interface ACK handshake pulse is initiated by the target MCU by issuing a negative edge in the BKGD pin. The hardware handshake protocol in Figure 5-11 specifies the timing when the BKGD pin is being driven, so the host should follow this timing constraint in order to avoid the risk of an electrical conflict in the BKGD pin. NOTE The only place the BKGD pin can have an electrical conflict is when one side is driving low and the other side is issuing a speedup pulse (high). Other “highs” are pulled rather than driven. However, at low rates the time of the speedup pulse can become lengthy and so the potential conflict time becomes longer as well. The ACK handshake protocol does not support nested ACK pulses. If a BDM command is not acknowledge by an ACK pulse, the host needs to abort the pending command first in order to be able to issue a new BDM command. When the CPU enters wait or stop while the host issues a hardware command (e.g., WRITE_BYTE), the target discards the incoming command due to the wait or stop being detected. Therefore, the command is not acknowledged by the target, which means that the ACK pulse will not be issued in this case. After a certain time the host (not aware of stop or wait) should decide to abort any possible pending ACK pulse in order to be sure a new command can be issued. Therefore, the protocol provides a mechanism in which a command, and its corresponding ACK, can be aborted. NOTE The ACK pulse does not provide a time out. This means for the GO_UNTIL command that it can not be distinguished if a stop or wait has been executed (command discarded and ACK not issued) or if the “UNTIL” condition (BDM active) is just not reached yet. Hence in any case where the ACK pulse of a command is not issued the possible pending command should be aborted before issuing a new command. See the handshake abort procedure described in Section 5.4.8, “Hardware Handshake Abort Procedure”. 5.4.8 Hardware Handshake Abort Procedure The abort procedure is based on the SYNC command. In order to abort a command, which had not issued the corresponding ACK pulse, the host controller should generate a low pulse in the BKGD pin by driving it low for at least 128 serial clock cycles and then driving it high for one serial clock cycle, providing a speedup pulse. By detecting this long low pulse in the BKGD pin, the target executes the SYNC protocol, see Section 5.4.9, “SYNC — Request Timed Reference Pulse”, and assumes that the pending command and therefore the related ACK pulse, are being aborted. Therefore, after the SYNC protocol has been completed the host is free to issue new BDM commands. For Firmware READ or WRITE commands it can not be guaranteed that the pending command is aborted when issuing a SYNC before the corresponding ACK pulse. There is a short latency time from the time the READ or WRITE access begins until it is finished and the corresponding ACK pulse is issued. The latency time depends on the firmware READ or WRITE command that is issued and if the serial interface is running on a different clock rate than the bus. When the SYNC command starts during this latency time the READ or WRITE command will not be aborted, but the corresponding ACK pulse will be aborted. A pending GO, TRACE1 or S12XS-Family Reference Manual, Rev. 1.03 180 PRELIMINARY Freescale Semiconductor Background Debug Module (S12XBDMV2) GO_UNTIL command can not be aborted. Only the corresponding ACK pulse can be aborted by the SYNC command. Although it is not recommended, the host could abort a pending BDM command by issuing a low pulse in the BKGD pin shorter than 128 serial clock cycles, which will not be interpreted as the SYNC command. The ACK is actually aborted when a negative edge is perceived by the target in the BKGD pin. The short abort pulse should have at least 4 clock cycles keeping the BKGD pin low, in order to allow the negative edge to be detected by the target. In this case, the target will not execute the SYNC protocol but the pending command will be aborted along with the ACK pulse. The potential problem with this abort procedure is when there is a conflict between the ACK pulse and the short abort pulse. In this case, the target may not perceive the abort pulse. The worst case is when the pending command is a read command (i.e., READ_BYTE). If the abort pulse is not perceived by the target the host will attempt to send a new command after the abort pulse was issued, while the target expects the host to retrieve the accessed memory byte. In this case, host and target will run out of synchronism. However, if the command to be aborted is not a read command the short abort pulse could be used. After a command is aborted the target assumes the next negative edge, after the abort pulse, is the first bit of a new BDM command. NOTE The details about the short abort pulse are being provided only as a reference for the reader to better understand the BDM internal behavior. It is not recommended that this procedure be used in a real application. Since the host knows the target serial clock frequency, the SYNC command (used to abort a command) does not need to consider the lower possible target frequency. In this case, the host could issue a SYNC very close to the 128 serial clock cycles length. Providing a small overhead on the pulse length in order to assure the SYNC pulse will not be misinterpreted by the target. See Section 5.4.9, “SYNC — Request Timed Reference Pulse”. Figure 5-13 shows a SYNC command being issued after a READ_BYTE, which aborts the READ_BYTE command. Note that, after the command is aborted a new command could be issued by the host computer. READ_BYTE CMD is Aborted by the SYNC Request (Out of Scale) SYNC Response From the Target (Out of Scale) BKGD Pin READ_BYTE Memory Address Host Target READ_STATUS Host Target New BDM Command Host Target BDM Decode and Starts to Execute the READ_BYTE Command New BDM Command Figure 5-13. ACK Abort Procedure at the Command Level NOTE Figure 5-13 does not represent the signals in a true timing scale Figure 5-14 shows a conflict between the ACK pulse and the SYNC request pulse. This conflict could occur if a POD device is connected to the target BKGD pin and the target is already in debug active mode. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 181 Background Debug Module (S12XBDMV2) Consider that the target CPU is executing a pending BDM command at the exact moment the POD is being connected to the BKGD pin. In this case, an ACK pulse is issued along with the SYNC command. In this case, there is an electrical conflict between the ACK speedup pulse and the SYNC pulse. Since this is not a probable situation, the protocol does not prevent this conflict from happening. BDM Clock (Target MCU) Target MCU Drives to BKGD Pin Host Drives SYNC To BKGD Pin BKGD Pin At Least 128 Cycles ACK Pulse Host and Target Drive to BKGD Pin Host SYNC Request Pulse High-Impedance Electrical Conflict Speedup Pulse 16 Cycles Figure 5-14. ACK Pulse and SYNC Request Conflict NOTE This information is being provided so that the MCU integrator will be aware that such a conflict could eventually occur. The hardware handshake protocol is enabled by the ACK_ENABLE and disabled by the ACK_DISABLE BDM commands. This provides backwards compatibility with the existing POD devices which are not able to execute the hardware handshake protocol. It also allows for new POD devices, that support the hardware handshake protocol, to freely communicate with the target device. If desired, without the need for waiting for the ACK pulse. The commands are described as follows: • ACK_ENABLE — enables the hardware handshake protocol. The target will issue the ACK pulse when a CPU command is executed by the CPU. The ACK_ENABLE command itself also has the ACK pulse as a response. • ACK_DISABLE — disables the ACK pulse protocol. In this case, the host needs to use the worst case delay time at the appropriate places in the protocol. The default state of the BDM after reset is hardware handshake protocol disabled. All the read commands will ACK (if enabled) when the data bus cycle has completed and the data is then ready for reading out by the BKGD serial pin. All the write commands will ACK (if enabled) after the data has been received by the BDM through the BKGD serial pin and when the data bus cycle is complete. See Section 5.4.3, “BDM Hardware Commands” and Section 5.4.4, “Standard BDM Firmware Commands” for more information on the BDM commands. S12XS-Family Reference Manual, Rev. 1.03 182 PRELIMINARY Freescale Semiconductor Background Debug Module (S12XBDMV2) The ACK_ENABLE sends an ACK pulse when the command has been completed. This feature could be used by the host to evaluate if the target supports the hardware handshake protocol. If an ACK pulse is issued in response to this command, the host knows that the target supports the hardware handshake protocol. If the target does not support the hardware handshake protocol the ACK pulse is not issued. In this case, the ACK_ENABLE command is ignored by the target since it is not recognized as a valid command. The BACKGROUND command will issue an ACK pulse when the CPU changes from normal to background mode. The ACK pulse related to this command could be aborted using the SYNC command. The GO command will issue an ACK pulse when the CPU exits from background mode. The ACK pulse related to this command could be aborted using the SYNC command. The GO_UNTIL command is equivalent to a GO command with exception that the ACK pulse, in this case, is issued when the CPU enters into background mode. This command is an alternative to the GO command and should be used when the host wants to trace if a breakpoint match occurs and causes the CPU to enter active background mode. Note that the ACK is issued whenever the CPU enters BDM, which could be caused by a breakpoint match or by a BGND instruction being executed. The ACK pulse related to this command could be aborted using the SYNC command. The TRACE1 command has the related ACK pulse issued when the CPU enters background active mode after one instruction of the application program is executed. The ACK pulse related to this command could be aborted using the SYNC command. 5.4.9 SYNC — Request Timed Reference Pulse The SYNC command is unlike other BDM commands because the host does not necessarily know the correct communication speed to use for BDM communications until after it has analyzed the response to the SYNC command. To issue a SYNC command, the host should perform the following steps: 1. Drive the BKGD pin low for at least 128 cycles at the lowest possible BDM serial communication frequency (the lowest serial communication frequency is determined by the crystal oscillator or the clock chosen by CLKSW.) 2. Drive BKGD high for a brief speedup pulse to get a fast rise time (this speedup pulse is typically one cycle of the host clock.) 3. Remove all drive to the BKGD pin so it reverts to high impedance. 4. Listen to the BKGD pin for the sync response pulse. Upon detecting the SYNC request from the host, the target performs the following steps: 1. Discards any incomplete command received or bit retrieved. 2. Waits for BKGD to return to a logic one. 3. Delays 16 cycles to allow the host to stop driving the high speedup pulse. 4. Drives BKGD low for 128 cycles at the current BDM serial communication frequency. 5. Drives a one-cycle high speedup pulse to force a fast rise time on BKGD. 6. Removes all drive to the BKGD pin so it reverts to high impedance. The host measures the low time of this 128 cycle SYNC response pulse and determines the correct speed for subsequent BDM communications. Typically, the host can determine the correct communication speed S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 183 Background Debug Module (S12XBDMV2) within a few percent of the actual target speed and the communication protocol can easily tolerate speed errors of several percent. As soon as the SYNC request is detected by the target, any partially received command or bit retrieved is discarded. This is referred to as a soft-reset, equivalent to a time-out in the serial communication. After the SYNC response, the target will consider the next negative edge (issued by the host) as the start of a new BDM command or the start of new SYNC request. Another use of the SYNC command pulse is to abort a pending ACK pulse. The behavior is exactly the same as in a regular SYNC command. Note that one of the possible causes for a command to not be acknowledged by the target is a host-target synchronization problem. In this case, the command may not have been understood by the target and so an ACK response pulse will not be issued. 5.4.10 Instruction Tracing When a TRACE1 command is issued to the BDM in active BDM, the CPU exits the standard BDM firmware and executes a single instruction in the user code. Once this has occurred, the CPU is forced to return to the standard BDM firmware and the BDM is active and ready to receive a new command. If the TRACE1 command is issued again, the next user instruction will be executed. This facilitates stepping or tracing through the user code one instruction at a time. If an interrupt is pending when a TRACE1 command is issued, the interrupt stacking operation occurs but no user instruction is executed. Once back in standard BDM firmware execution, the program counter points to the first instruction in the interrupt service routine. Be aware when tracing through the user code that the execution of the user code is done step by step but all peripherals are free running. Hence possible timing relations between CPU code execution and occurrence of events of other peripherals no longer exist. Do not trace the CPU instruction BGND used for soft breakpoints. Tracing the BGND instruction will result in a return address pointing to BDM firmware address space. When tracing through user code which contains stop or wait instructions the following will happen when the stop or wait instruction is traced: The CPU enters stop or wait mode and the TRACE1 command can not be finished before leaving the low power mode. This is the case because BDM active mode can not be entered after CPU executed the stop instruction. However all BDM hardware commands except the BACKGROUND command are operational after tracing a stop or wait instruction and still being in stop or wait mode. If system stop mode is entered (all bus masters are in stop mode) no BDM command is operational. As soon as stop or wait mode is exited the CPU enters BDM active mode and the saved PC value points to the entry of the corresponding interrupt service routine. In case the handshake feature is enabled the corresponding ACK pulse of the TRACE1 command will be discarded when tracing a stop or wait instruction. Hence there is no ACK pulse when BDM active mode is entered as part of the TRACE1 command after CPU exited from stop or wait mode. All valid commands sent during CPU being in stop or wait mode or after CPU exited from stop or wait mode will have an ACK pulse. The handshake feature becomes disabled only when system S12XS-Family Reference Manual, Rev. 1.03 184 PRELIMINARY Freescale Semiconductor Background Debug Module (S12XBDMV2) stop mode has been reached. Hence after a system stop mode the handshake feature must be enabled again by sending the ACK_ENABLE command. 5.4.11 Serial Communication Time Out The host initiates a host-to-target serial transmission by generating a falling edge on the BKGD pin. If BKGD is kept low for more than 128 target clock cycles, the target understands that a SYNC command was issued. In this case, the target will keep waiting for a rising edge on BKGD in order to answer the SYNC request pulse. If the rising edge is not detected, the target will keep waiting forever without any time-out limit. Consider now the case where the host returns BKGD to logic one before 128 cycles. This is interpreted as a valid bit transmission, and not as a SYNC request. The target will keep waiting for another falling edge marking the start of a new bit. If, however, a new falling edge is not detected by the target within 512 clock cycles since the last falling edge, a time-out occurs and the current command is discarded without affecting memory or the operating mode of the MCU. This is referred to as a soft-reset. If a read command is issued but the data is not retrieved within 512 serial clock cycles, a soft-reset will occur causing the command to be disregarded. The data is not available for retrieval after the time-out has occurred. This is the expected behavior if the handshake protocol is not enabled. However, consider the behavior where the BDM is running in a frequency much greater than the CPU frequency. In this case, the command could time out before the data is ready to be retrieved. In order to allow the data to be retrieved even with a large clock frequency mismatch (between BDM and CPU) when the hardware handshake protocol is enabled, the time out between a read command and the data retrieval is disabled. Therefore, the host could wait for more then 512 serial clock cycles and still be able to retrieve the data from an issued read command. However, once the handshake pulse (ACK pulse) is issued, the time-out feature is reactivated, meaning that the target will time out after 512 clock cycles. Therefore, the host needs to retrieve the data within a 512 serial clock cycles time frame after the ACK pulse had been issued. After that period, the read command is discarded and the data is no longer available for retrieval. Any negative edge in the BKGD pin after the time-out period is considered to be a new command or a SYNC request. Note that whenever a partially issued command, or partially retrieved data, has occurred the time out in the serial communication is active. This means that if a time frame higher than 512 serial clock cycles is observed between two consecutive negative edges and the command being issued or data being retrieved is not complete, a soft-reset will occur causing the partially received command or data retrieved to be disregarded. The next negative edge in the BKGD pin, after a soft-reset has occurred, is considered by the target as the start of a new BDM command, or the start of a SYNC request pulse. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 185 Background Debug Module (S12XBDMV2) S12XS-Family Reference Manual, Rev. 1.03 186 PRELIMINARY Freescale Semiconductor Chapter 6 S12X Debug (S12XDBGV3) Module Table 6-1. Revision History Revision Number Revision Date V03.20 14 Sep 2007 V03.21 23 Oct 2007 V03.22 V03.23 V03.24 V03.25 12 Nov 2007 13 Nov 2007 04 Jan 2008 14 May 2008 Sections Affected Description of Changes 6.3.2.7/6-197 - Clarified reserved State Sequencer encodings. 6.4.2.2/6-210 - Added single databyte comparison limitation information 6.4.2.4/6-211 - Added statement about interrupt vector fetches whilst tagging. 6.4.5.2/6-215 - Removed LOOP1 tracing restriction NOTE. 6.4.5.5/6-219 - Added pin reset effect NOTE. General - Text readability improved, typo removed. 6.4.5.3/6-217 - Corrected bit name. - Updated Revision History Table format. Corrected other paragraph formats. 6.1 Introduction The S12XDBG module provides an on-chip trace buffer with flexible triggering capability to allow nonintrusive debug of application software. The S12XDBG module is optimized for the S12X 16-bit architecture and allows debugging of CPU12X module operations. Typically the S12XDBG module is used in conjunction with the S12XBDM module, whereby the user configures the S12XDBG module for a debugging session over the BDM interface. Once configured the S12XDBG module is armed and the device leaves BDM Mode returning control to the user program, which is then monitored by the S12XDBG module. Alternatively the S12XDBG module can be configured over a serial interface using SWI routines. 6.1.1 Glossary Table 6-2. Glossary Of Terms Term COF BDM DUG WORD Data Line Definition Change Of Flow. Change in the program flow due to a conditional branch, indexed jump or interrupt Background Debug Mode Device User Guide, describing the features of the device into which the DBG is integrated 16 bit data entity 64 bit data entity S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 187 S12X Debug (S12XDBGV3) Module Term CPU Tag Table 6-2. Glossary Of Terms (continued) Definition CPU12X module Tags can be attached to CPU opcodes as they enter the instruction pipe. If the tagged opcode reaches the execution stage a tag hit occurs. 6.1.2 Overview The comparators monitor the bus activity of the CPU12X. When a match occurs the control logic can trigger the state sequencer to a new state. On a transition to the Final State, bus tracing is triggered and/or a breakpoint can be generated. Independent of comparator matches a transition to Final State with associated tracing and breakpoint can be triggered by writing to the TRIG control bit. The trace buffer is visible through a 2-byte window in the register address map and can be read out using standard 16-bit word reads. Tracing is disabled when the MCU system is secured. 6.1.3 Features • Four comparators (A, B, C, and D) — Comparators A and C compare the full address bus and full 16-bit data bus — Comparators A and C feature a data bus mask register — Comparators B and D compare the full address bus only — Each comparator can be configured to monitor CPU12X buses — Each comparator features selection of read or write access cycles — Comparators B and D allow selection of byte or word access cycles — Comparisons can be used as triggers for the state sequencer • Three comparator modes — Simple address/data comparator match mode — Inside address range mode, Addmin ≤ Address ≤ Addmax — Outside address range match mode, Address < Addmin or Address > Addmax • Two types of triggers — Tagged — This triggers just before a specific instruction begins execution — Force — This triggers on the first instruction boundary after a match occurs. • The following types of breakpoints — CPU12X breakpoint entering BDM on breakpoint (BDM) — CPU12X breakpoint executing SWI on breakpoint (SWI) • TRIG Immediate software trigger independent of comparators • Four trace modes — Normal: change of flow (COF) PC information is stored (see Section 6.4.5.2.1) for change of flow definition. S12XS-Family Reference Manual, Rev. 1.03 188 PRELIMINARY Freescale Semiconductor S12X Debug (S12XDBGV3) Module — Loop1: same as Normal but inhibits consecutive duplicate source address entries — Detail: address and data for all cycles except free cycles and opcode fetches are stored — Pure PC: All program counter addresses are stored. • 4-stage state sequencer for trace buffer control — Tracing session trigger linked to Final State of state sequencer — Begin, End, and Mid alignment of tracing to trigger 6.1.4 Modes of Operation The S12XDBG module can be used in all MCU functional modes. During BDM hardware accesses and whilst the BDM module is active, CPU12X monitoring is disabled. Thus breakpoints, comparators, and CPU12X bus tracing are disabled . When the CPU12X enters active BDM Mode through a BACKGROUND command, with the S12XDBG module armed, the S12XDBG remains armed. The S12XDBG module tracing is disabled if the MCU is secure. However, breakpoints can still be generated if the MCU is secure. BDM Enable x 0 0 1 1 BDM Active x 0 1 0 1 Table 6-3. Mode Dependent Restriction Summary MCU Secure 1 0 0 0 0 Comparator Matches Enabled Yes Yes Yes No Breakpoints Possible Tagging Possible Yes Yes Only SWI Yes Active BDM not possible when not enabled Yes Yes No No Tracing Possible No Yes Yes No S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 189 S12X Debug (S12XDBGV3) Module 6.1.5 Block Diagram TAGHITS SECURE S12XCPU BUS COMPARATOR A COMPARATOR B COMPARATOR C COMPARATOR D BUS INTERFACE COMPARATOR MATCH CONTROL MATCH0 MATCH1 MATCH2 MATCH3 TAGS BREAKPOINT REQUESTS S12XCPU TRIGGER TAG & TRIGGER CONTROL LOGIC STATE STATE STATE SEQUENCER TRACE CONTROL TRIGGER READ TRACE DATA (DBG READ DATA BUS) Figure 6-1. Debug Module Block Diagram 6.2 External Signal Description The S12XDBG sub-module features no external signals. 6.3 Memory Map and Registers TRACE BUFFER 6.3.1 Module Memory Map A summary of the registers associated with the S12XDBG sub-block is shown in Table 6-2. Detailed descriptions of the registers and bits are given in the subsections that follow. Address 0x0020 0x0021 Name R DBGC1 W R DBGSR W Bit 7 ARM TBF 6 0 TRIG 0 5 reserved 0 4 BDM 0 3 2 DBGBRK reserved 0 SSF2 0x0022 0x0023 R DBGTCR reserved TSOURCE W R 0 0 DBGC2 W TRANGE 0 0 TRCMOD CDCM Figure 6-2. Quick Reference to S12XDBG Registers 1 Bit 0 COMRV SSF1 SSF0 TALIGN ABCM S12XS-Family Reference Manual, Rev. 1.03 190 PRELIMINARY Freescale Semiconductor S12X Debug (S12XDBGV3) Module Address 0x0024 Name R DBGTBH W Bit 7 Bit 15 6 Bit 14 5 Bit 13 4 Bit 12 3 Bit 11 2 Bit 10 1 Bit 9 0x0025 R DBGTBL W Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 R 0 0x0026 DBGCNT W CNT R 0 0 0 0 0x0027 DBGSCRX SC3 SC2 SC1 W R 0 0 0 0 MC3 MC2 MC1 0x0027 DBGMFR W 0x00281 DBGXCTL R (COMPA/C) W 0 NDB TAG BRK RW RWE reserved 0x00282 DBGXCTL R (COMPB/D) W SZE SZ TAG BRK RW RWE reserved R 0 0x0029 DBGXAH Bit 22 21 20 19 18 17 W R 0x002A DBGXAM Bit 15 14 13 12 11 10 9 W R 0x002B DBGXAL Bit 7 6 5 4 3 2 1 W R 0x002C DBGXDH Bit 15 14 13 12 11 10 9 W R 0x002D DBGXDL Bit 7 6 5 4 3 2 1 W R 0x002E DBGXDHM Bit 15 14 13 12 11 10 9 W R 0x002F DBGXDLM Bit 7 6 5 4 3 2 1 W 1 This represents the contents if the Comparator A or C control register is blended into this address. 2 This represents the contents if the Comparator B or D control register is blended into this address Figure 6-2. Quick Reference to S12XDBG Registers Bit 0 Bit 8 Bit 0 SC0 MC0 COMPE COMPE Bit 16 Bit 8 Bit 0 Bit 8 Bit 0 Bit 8 Bit 0 6.3.2 Register Descriptions This section consists of the S12XDBG control and trace buffer register descriptions in address order. Each comparator has a bank of registers that are visible through an 8-byte window between 0x0028 and 0x002F in the S12XDBG module register address map. When ARM is set in DBGC1, the only bits in the S12XDBG module registers that can be written are ARM, TRIG, and COMRV[1:0] S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 191 S12X Debug (S12XDBGV3) Module 6.3.2.1 Debug Control Register 1 (DBGC1) Address: 0x0020 R W Reset 7 ARM 0 6 0 TRIG 0 5 reserved 0 4 BDM 0 3 DBGBRK 0 2 reserved 0 1 0 COMRV 0 0 Figure 6-3. Debug Control Register (DBGC1) Read: Anytime Write: Bits 7, 1, 0 anytime Bit 6 can be written anytime but always reads back as 0. Bits 5:2 anytime S12XDBG is not armed. NOTE If a write access to DBGC1 with the ARM bit position set occurs simultaneously to a hardware disarm from an internal trigger event, then the ARM bit is cleared due to the hardware disarm. NOTE When disarming the S12XDBG by clearing ARM with software, the contents of bits[5:2] are not affected by the write, since up until the write operation, ARM = 1 preventing these bits from being written. These bits must be cleared using a second write if required. Table 6-4. DBGC1 Field Descriptions Field 7 ARM 6 TRIG 5 reserved 4 BDM Description Arm Bit — The ARM bit controls whether the S12XDBG module is armed. This bit can be set and cleared by user software and is automatically cleared on completion of a tracing session, or if a breakpoint is generated with tracing not enabled. On setting this bit the state sequencer enters State1. 0 Debugger disarmed 1 Debugger armed Immediate Trigger Request Bit — This bit when written to 1 requests an immediate trigger independent of comparator signal status. When tracing is complete a forced breakpoint may be generated depending upon DBGBRK and BDM bit settings. This bit always reads back a 0. Writing a 0 to this bit has no effect. If TSOURCE is clear no tracing is carried out. If tracing has already commenced using BEGIN- or MID trigger alignment, it continues until the end of the tracing session as defined by the TALIGN bit settings, thus TRIG has no affect. In secure mode tracing is disabled and writing to this bit has no effect. 0 Do not trigger until the state sequencer enters the Final State. 1 Trigger immediately . This bit is reserved, setting it has no meaning or effect. Background Debug Mode Enable — This bit determines if an S12X breakpoint causes the system to enter Background Debug Mode (BDM) or initiate a Software Interrupt (SWI). If this bit is set but the BDM is not enabled by the ENBDM bit in the BDM module, then breakpoints default to SWI. 0 Breakpoint to Software Interrupt if BDM inactive. Otherwise no breakpoint. 1 Breakpoint to BDM, if BDM enabled. Otherwise breakpoint to SWI S12XS-Family Reference Manual, Rev. 1.03 192 PRELIMINARY Freescale Semiconductor S12X Debug (S12XDBGV3) Module Table 6-4. DBGC1 Field Descriptions (continued) Field 3 DBGBRK 1–0 COMRV Description S12XDBG Breakpoint Enable Bit — The DBGBRK bit controls whether the debugger will request a breakpoint to S12XCPU upon reaching the state sequencer Final State. If tracing is enabled, the breakpoint is generated on completion of the tracing session. If tracing is not enabled, the breakpoint is generated immediately. Please refer to Section 6.4.7 for further details. 0 No breakpoint on trigger. 1 Breakpoint on trigger Comparator Register Visibility Bits — These bits determine which bank of comparator register is visible in the 8-byte window of the S12XDBG module address map, located between 0x0028 to 0x002F. Furthermore these bits determine which register is visible at the address 0x0027. See Table 6-5. COMRV 00 01 10 11 Table 6-5. COMRV Encoding Visible Comparator Comparator A Comparator B Comparator C Comparator D Visible Register at 0x0027 DBGSCR1 DBGSCR2 DBGSCR3 DBGMFR 6.3.2.2 Debug Status Register (DBGSR) Address: 0x0021 7 R TBF W Reset — POR 0 6 5 4 3 2 0 0 0 0 SSF2 0 0 0 0 0 0 0 0 0 0 = Unimplemented or Reserved Figure 6-4. Debug Status Register (DBGSR) 1 SSF1 0 0 0 SSF0 0 0 Read: Anytime Write: Never Table 6-6. DBGSR Field Descriptions Field 7 TBF 2–0 SSF[2:0] Description Trace Buffer Full — The TBF bit indicates that the trace buffer has stored 64 or more lines of data since it was last armed. If this bit is set, then all 64 lines will be valid data, regardless of the value of DBGCNT bits CNT[6:0]. The TBF bit is cleared when ARM in DBGC1 is written to a one. The TBF is cleared by the power on reset initialization. Other system generated resets have no affect on this bit State Sequencer Flag Bits — The SSF bits indicate in which state the State Sequencer is currently in. During a debug session on each transition to a new state these bits are updated. If the debug session is ended by software clearing the ARM bit, then these bits retain their value to reflect the last state of the state sequencer before disarming. If a debug session is ended by an internal trigger, then the state sequencer returns to state0 and these bits are cleared to indicate that state0 was entered during the session. On arming the module the state sequencer enters state1 and these bits are forced to SSF[2:0] = 001. See Table 6-7. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 193 S12X Debug (S12XDBGV3) Module Table 6-7. SSF[2:0] — State Sequence Flag Bit Encoding SSF[2:0] 000 001 010 011 100 101,110,111 Current State State0 (disarmed) State1 State2 State3 Final State Reserved 6.3.2.3 Debug Trace Control Register (DBGTCR) Address: 0x0022 R W Reset 7 reserved 0 6 TSOURCE 5 4 TRANGE 3 2 TRCMOD 0 0 0 0 0 Figure 6-5. Debug Trace Control Register (DBGTCR) 1 0 TALIGN 0 0 Read: Anytime Write: Bits 7:6 only when S12XDBG is neither secure nor armed. Bits 5:0 anytime the module is disarmed. WARNING DBGTCR[7] is reserved. Setting this bit maps the tracing to an unimplemented bus, thus preventing proper operation. Table 6-8. DBGTCR Field Descriptions Field Description 6 TSOURCE Trace Source Control Bits — The TSOURCE enables the tracing session. If the MCU system is secured, this bit cannot be set and tracing is inhibited. 0 No tracing selected 1 Tracing selected 5–4 TRANGE Trace Range Bits — The TRANGE bits allow filtering of trace information from a selected address range when tracing from the CPU12X in Detail Mode. To use a comparator for range filtering, the corresponding COMPE bits must remain cleared. If the COMPE bit is not clear then the comparator will also be used to generate state sequence triggers. See Table 6-9. 3–2 TRCMOD Trace Mode Bits — See Section 6.4.5.2 for detailed Trace Mode descriptions. In Normal Mode, change of flow information is stored. In Loop1 Mode, change of flow information is stored but redundant entries into trace memory are inhibited. In Detail Mode, address and data for all memory and register accesses is stored. See Table 6-10. 1–0 Trigger Align Bits — These bits control whether the trigger is aligned to the beginning, end or the middle of a TALIGN tracing session. See Table 6-11. S12XS-Family Reference Manual, Rev. 1.03 194 PRELIMINARY Freescale Semiconductor S12X Debug (S12XDBGV3) Module 6.3.2.4 TRANGE 00 01 10 11 Table 6-9. TRANGE Trace Range Encoding Tracing Range Trace from all addresses (No filter) Trace only in address range from $00000 to Comparator D Trace only in address range from Comparator C to $7FFFFF Trace only in range from Comparator C to Comparator D Table 6-10. TRCMOD Trace Mode Bit Encoding TRCMOD 00 01 10 11 Description Normal Loop1 Detail Pure PC TALIGN 00 01 10 11 Table 6-11. TALIGN Trace Alignment Encoding Description Trigger at end of stored data Trigger before storing data Trace buffer entries before and after trigger Reserved Debug Control Register2 (DBGC2) Address: 0x0023 7 6 5 4 R 0 0 0 0 W Reset 0 0 0 0 = Unimplemented or Reserved 3 2 CDCM 0 0 Figure 6-6. Debug Control Register2 (DBGC2) Read: Anytime Write: Anytime the module is disarmed. This register configures the comparators for range matching. 1 0 ABCM 0 0 Table 6-12. DBGC2 Field Descriptions Field Description 3–2 C and D Comparator Match Control — These bits determine the C and D comparator match mapping as CDCM[1:0] described in Table 6-13. 1–0 A and B Comparator Match Control — These bits determine the A and B comparator match mapping as ABCM[1:0] described in Table 6-14. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 195 S12X Debug (S12XDBGV3) Module Table 6-13. CDCM Encoding CDCM Description 00 Match2 mapped to comparator C match....... Match3 mapped to comparator D match. 01 Match2 mapped to comparator C/D inside range....... Match3 disabled. 10 Match2 mapped to comparator C/D outside range....... Match3 disabled. 11 Reserved1 1 Currently defaults to Match2 mapped to comparator C : Match3 mapped to comparator D Table 6-14. ABCM Encoding ABCM Description 00 Match0 mapped to comparator A match....... Match1 mapped to comparator B match. 01 Match 0 mapped to comparator A/B inside range....... Match1 disabled. 10 Match 0 mapped to comparator A/B outside range....... Match1 disabled. 11 Reserved1 1 Currently defaults to Match0 mapped to comparator A : Match1 mapped to comparator B 6.3.2.5 Debug Trace Buffer Register (DBGTBH:DBGTBL) Address: 0x0024, 0x0025 15 14 13 12 11 10 9 R Bit 15 Bit 14 Bit 13 Bit 12 Bit 11 Bit 10 Bit 9 W POR X X X X X X X Other Resets — — — — — — — 8 Bit 8 X — 7 Bit 7 X — 6 Bit 6 X — 5 Bit 5 X — 4 Bit 4 X — 3 Bit 3 X — 2 Bit 2 X — 1 Bit 1 X — 0 Bit 0 X — Figure 6-7. Debug Trace Buffer Register (DBGTB) Read: Only when unlocked AND not secured AND not armed AND with the TSOURCE bit set. Write: Aligned word writes when disarmed unlock the trace buffer for reading but do not affect trace buffer contents. Table 6-15. DBGTB Field Descriptions Field 15–0 Bit[15:0] Description Trace Buffer Data Bits — The Trace Buffer Register is a window through which the 64-bit wide data lines of the Trace Buffer may be read 16 bits at a time. Each valid read of DBGTB increments an internal trace buffer pointer which points to the next address to be read. When the ARM bit is written to 1 the trace buffer is locked to prevent reading. The trace buffer can only be unlocked for reading by writing to DBGTB with an aligned word write when the module is disarmed. The DBGTB register can be read only as an aligned word, any byte reads or misaligned access of these registers will return 0 and will not cause the trace buffer pointer to increment to the next trace buffer address. The same is true for word reads while the debugger is armed. The POR state is undefined Other resets do not affect the trace buffer contents. . S12XS-Family Reference Manual, Rev. 1.03 196 PRELIMINARY Freescale Semiconductor 6.3.2.6 Debug Count Register (DBGCNT) S12X Debug (S12XDBGV3) Module Address: 0x0026 7 6 5 4 3 2 1 0 R 0 CNT W Reset 0 POR 0 — — — — — — — 0 0 0 0 0 0 0 = Unimplemented or Reserved Figure 6-8. Debug Count Register (DBGCNT) Read: Anytime Write: Never Table 6-16. DBGCNT Field Descriptions Field Description 6–0 CNT[6:0] Count Value — The CNT bits [6:0] indicate the number of valid data 64-bit data lines stored in the Trace Buffer. Table 6-17 shows the correlation between the CNT bits and the number of valid data lines in the Trace Buffer. When the CNT rolls over to zero, the TBF bit in DBGSR is set and incrementing of CNT will continue in endtrigger or mid-trigger mode. The DBGCNT register is cleared when ARM in DBGC1 is written to a one. The DBGCNT register is cleared by power-on-reset initialization but is not cleared by other system resets. Thus should a reset occur during a debug session, the DBGCNT register still indicates after the reset, the number of valid trace buffer entries stored before the reset occurred. The DBGCNT register is not decremented when reading from the trace buffer. TBF (DBGSR) 0 0 0 0 1 1 Table 6-17. CNT Decoding Table CNT[6:0] 0000000 0000001 0000010 0000100 0000110 .. 1111100 1111110 0000000 0000010 .. .. 1111110 Description No data valid 32 bits of one line valid 1 line valid 2 lines valid 3 lines valid .. 62 lines valid 63 lines valid 64 lines valid; if using Begin trigger alignment, ARM bit will be cleared and the tracing session ends. 64 lines valid, oldest data has been overwritten by most recent data 6.3.2.7 Debug State Control Registers There is a dedicated control register for each of the state sequencer states 1 to 3 that determines if transitions from that state are allowed, depending upon comparator matches or tag hits, and defines the S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 197 S12X Debug (S12XDBGV3) Module next state for the state sequencer following a match. The three debug state control registers are located at the same address in the register address map (0x0027). Each register can be accessed using the COMRV bits in DBGC1 to blend in the required register. The COMRV = 11 value blends in the match flag register (DBGMFR). Table 6-18. State Control Register Access Encoding COMRV 00 01 10 11 Visible State Control Register DBGSCR1 DBGSCR2 DBGSCR3 DBGMFR 6.3.2.7.1 Debug State Control Register 1 (DBGSCR1) Address: 0x0027 7 6 5 4 R 0 0 0 0 W Reset 0 0 0 0 = Unimplemented or Reserved 3 SC3 0 2 SC2 0 1 SC1 0 0 SC0 0 Figure 6-9. Debug State Control Register 1 (DBGSCR1) Read: If COMRV[1:0] = 00 Write: If COMRV[1:0] = 00 and S12XDBG is not armed. This register is visible at 0x0027 only with COMRV[1:0] = 00. The state control register 1 selects the targeted next state whilst in State1. The matches refer to the match channels of the comparator match control logic as depicted in Figure 6-1 and described in Section 6.3.2.8.1”. Comparators must be enabled by setting the comparator enable bit in the associated DBGXCTL control register. Table 6-19. DBGSCR1 Field Descriptions Field 3–0 SC[3:0] Description These bits select the targeted next state whilst in State1, based upon the match event. SC[3:0] 0000 0001 0010 0011 0100 0101 0110 Table 6-20. State1 Sequencer Next State Selection Description Any match triggers to state2 Any match triggers to state3 Any match triggers to Final State Match2 triggers to State2....... Other matches have no effect Match2 triggers to State3....... Other matches have no effect Match2 triggers to Final State....... Other matches have no effect Match0 triggers to State2....... Match1 triggers to State3....... Other matches have no effect S12XS-Family Reference Manual, Rev. 1.03 198 PRELIMINARY Freescale Semiconductor S12X Debug (S12XDBGV3) Module Table 6-20. State1 Sequencer Next State Selection (continued) SC[3:0] 0111 1000 1001 1010 1011 1100 1101 1110 1111 Description Match1 triggers to State3....... Match0 triggers Final State....... Other matches have no effect Match0 triggers to State2....... Match2 triggers to State3....... Other matches have no effect Match2 triggers to State3....... Match0 triggers Final State....... Other matches have no effect Match1 triggers to State2....... Match3 triggers to State3....... Other matches have no effect Match3 triggers to State3....... Match1 triggers to Final State....... Other matches have no effect Match3 has no effect....... All other matches (M0,M1,M2) trigger to State2 Reserved. (No match triggers state sequencer transition) Reserved. (No match triggers state sequencer transition) Reserved. (No match triggers state sequencer transition) The trigger priorities described in Table 6-39 dictate that in the case of simultaneous matches, the match on the lower channel number (0,1,2,3) has priority. The SC[3:0] encoding ensures that a match leading to final state has priority over all other matches. 6.3.2.7.2 Debug State Control Register 2 (DBGSCR2) Address: 0x0027 7 6 5 4 R 0 0 0 0 W Reset 0 0 0 0 = Unimplemented or Reserved 3 SC3 0 2 SC2 0 1 SC1 0 0 SC0 0 Figure 6-10. Debug State Control Register 2 (DBGSCR2) Read: If COMRV[1:0] = 01 Write: If COMRV[1:0] = 01 and S12XDBG is not armed. This register is visible at 0x0027 only with COMRV[1:0] = 01. The state control register 2 selects the targeted next state whilst in State2. The matches refer to the match channels of the comparator match control logic as depicted in Figure 6-1 and described in Section 6.3.2.8.1”. Comparators must be enabled by setting the comparator enable bit in the associated DBGXCTL control register. Field 3–0 SC[3:0] Table 6-21. DBGSCR2 Field Descriptions Description These bits select the targeted next state whilst in State2, based upon the match event. SC[3:0] 0000 0001 0010 0011 0100 Table 6-22. State2 —Sequencer Next State Selection Description Any match triggers to state1 Any match triggers to state3 Any match triggers to Final State Match3 triggers to State1....... Other matches have no effect Match3 triggers to State3....... Other matches have no effect S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 199 S12X Debug (S12XDBGV3) Module Table 6-22. State2 —Sequencer Next State Selection (continued) SC[3:0] 0101 0110 0111 1000 1001 1010 1011 1100 1101 1110 1111 Description Match3 triggers to Final State....... Other matches have no effect Match0 triggers to State1....... Match1 triggers to State3....... Other matches have no effect Match1 triggers to State3....... Match0 triggers Final State....... Other matches have no effect Match0 triggers to State1....... Match2 triggers to State3....... Other matches have no effect Match2 triggers to State3....... Match0 triggers Final State....... Other matches have no effect Match1 triggers to State1....... Match3 triggers to State3....... Other matches have no effect Match3 triggers to State3....... Match1 triggers Final State....... Other matches have no effect Match2 triggers to State1..... Match3 trigger to Final State Match2 has no affect, all other matches (M0,M1,M3) trigger to Final State Reserved. (No match triggers state sequencer transition) Reserved. (No match triggers state sequencer transition) The trigger priorities described in Table 6-39 dictate that in the case of simultaneous matches, the match on the lower channel number (0,1,2,3) has priority. The SC[3:0] encoding ensures that a match leading to final state has priority over all other matches. 6.3.2.7.3 Debug State Control Register 3 (DBGSCR3) Address: 0x0027 7 6 5 4 R 0 0 0 0 W Reset 0 0 0 0 = Unimplemented or Reserved 3 SC3 0 2 SC2 0 1 SC1 0 0 SC0 0 Figure 6-11. Debug State Control Register 3 (DBGSCR3) Read: If COMRV[1:0] = 10 Write: If COMRV[1:0] = 10 and S12XDBG is not armed. This register is visible at 0x0027 only with COMRV[1:0] = 10. The state control register three selects the targeted next state whilst in State3. The matches refer to the match channels of the comparator match control logic as depicted in Figure 6-1 and described in Section 6.3.2.8.1”. Comparators must be enabled by setting the comparator enable bit in the associated DBGXCTL control register. Table 6-23. DBGSCR3 Field Descriptions Field 3–0 SC[3:0] Description These bits select the targeted next state whilst in State3, based upon the match event. SC[3:0] 0000 0001 Table 6-24. State3 — Sequencer Next State Selection Description Any match triggers to state1 Any match triggers to state2 S12XS-Family Reference Manual, Rev. 1.03 200 PRELIMINARY Freescale Semiconductor S12X Debug (S12XDBGV3) Module Table 6-24. State3 — Sequencer Next State Selection SC[3:0] 0010 0011 0100 0101 0110 0111 1000 1001 1010 1011 1100 1101 1110 1111 Description Any match triggers to Final State Match0 triggers to State1....... Other matches have no effect Match0 triggers to State2....... Other matches have no effect Match0 triggers to Final State.......Match1 triggers to State1...Other matches have no effect Match1 triggers to State1....... Other matches have no effect Match1 triggers to State2....... Other matches have no effect Match1 triggers to Final State....... Other matches have no effect Match2 triggers to State2....... Match0 triggers to Final State....... Other matches have no effect Match1 triggers to State1....... Match3 triggers to State2....... Other matches have no effect Match3 triggers to State2....... Match1 triggers to Final State....... Other matches have no effect Match2 triggers to Final State....... Other matches have no effect Match3 triggers to Final State....... Other matches have no effect Reserved. (No match triggers state sequencer transition) Reserved. (No match triggers state sequencer transition) The trigger priorities described in Table 6-39 dictate that in the case of simultaneous matches, the match on the lower channel number (0,1,2,3) has priority. The SC[3:0] encoding ensures that a match leading to final state has priority over all other matches. 6.3.2.7.4 Debug Match Flag Register (DBGMFR) Address: 0x0027 7 6 5 4 R 0 0 0 0 W Reset 0 0 0 0 = Unimplemented or Reserved 3 MC3 0 2 MC2 0 1 MC1 0 0 MC0 0 Figure 6-12. Debug Match Flag Register (DBGMFR) Read: If COMRV[1:0] = 11 Write: Never DBGMFR is visible at 0x0027 only with COMRV[1:0] = 11. It features four flag bits each mapped directly to a channel. Should a match occur on the channel during the debug session, then the corresponding flag is set and remains set until the next time the module is armed by writing to the ARM bit. Thus the contents are retained after a debug session for evaluation purposes. These flags cannot be cleared by software, they are cleared only when arming the module. A set flag does not inhibit the setting of other flags. Once a flag is set, further triggers on the same channel have no affect. 6.3.2.8 Comparator Register Descriptions Each comparator has a bank of registers that are visible through an 8-byte window in the S12XDBG module register address map. Comparators A and C consist of 8 register bytes (3 address bus compare registers, two data bus compare registers, two data bus mask registers and a control register). S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 201 S12X Debug (S12XDBGV3) Module Comparators B and D consist of four register bytes (three address bus compare registers and a control register). Each set of comparator registers is accessible in the same 8-byte window of the register address map and can be accessed using the COMRV bits in the DBGC1 register. If the Comparators B or D are accessed through the 8-byte window, then only the address and control bytes are visible, the 4 bytes associated with data bus and data bus masking read as zero and cannot be written. Furthermore the control registers for comparators B and D differ from those of comparators A and C. 0x0028 0x0029 0x002A 0x002B 0x002C 0x002D 0x002E 0x002F Table 6-25. Comparator Register Layout CONTROL ADDRESS HIGH ADDRESS MEDIUM ADDRESS LOW DATA HIGH COMPARATOR DATA LOW COMPARATOR DATA HIGH MASK DATA LOW MASK Read/Write Read/Write Read/Write Read/Write Read/Write Read/Write Read/Write Read/Write Comparators A,B,C,D Comparators A,B,C,D Comparators A,B,C,D Comparators A,B,C,D Comparator A and C only Comparator A and C only Comparator A and C only Comparator A and C only 6.3.2.8.1 Debug Comparator Control Register (DBGXCTL) The contents of this register bits 7 and 6 differ depending upon which comparator registers are visible in the 8-byte window of the DBG module register address map. Address: 0x0028 7 R 0 W 6 5 4 3 2 1 NDB TAG BRK RW RWE reserved Reset 0 0 0 0 0 0 0 = Unimplemented or Reserved Figure 6-13. Debug Comparator Control Register (Comparators A and C) 0 COMPE 0 Address: 0x0028 7 6 5 4 3 2 1 0 R SZE SZ TAG BRK RW RWE reserved COMPE W Reset 0 0 0 0 0 0 0 0 Figure 6-14. Debug Comparator Control Register (Comparators B and D) Read: Anytime. See Table 6-26 for visible register encoding. Write: If DBG not armed. See Table 6-26 for visible register encoding. WARNING DBGXCTL[1] is reserved. Setting this bit maps the corresponding comparator to an S12XS-Family Reference Manual, Rev. 1.03 202 PRELIMINARY Freescale Semiconductor S12X Debug (S12XDBGV3) Module unimplemented bus, thus preventing proper operation. The DBGC1_COMRV bits determine which comparator control, address, data and datamask registers are visible in the 8-byte window from 0x0028 to 0x002F as shown in Section Table 6-26. Table 6-26. Comparator Address Register Visibility COMRV 00 01 10 11 Visible Comparator DBGACTL, DBGAAH ,DBGAAM, DBGAAL, DBGADH, DBGADL, DBGADHM, DBGADLM DBGBCTL, DBGBAH, DBGBAM, DBGBAL DBGCCTL, DBGCAH, DBGCAM, DBGCAL, DBGCDH, DBGCDL, DBGCDHM, DBGCDLM DBGDCTL, DBGDAH, DBGDAM, DBGDAL Table 6-27. DBGXCTL Field Descriptions Field Description 7 SZE (Comparators B and D) Size Comparator Enable Bit — The SZE bit controls whether access size comparison is enabled for the associated comparator. This bit is ignored if the TAG bit in the same register is set. 0 Word/Byte access size is not used in comparison 1 Word/Byte access size is used in comparison 6 NDB (Comparators A and C Not Data Bus — The NDB bit controls whether the match occurs when the data bus matches the comparator register value or when the data bus differs from the register value. Furthermore data bus bits can be individually masked using the comparator data mask registers. This bit is only available for comparators A and C. This bit is ignored if the TAG bit in the same register is set. This bit position has an SZ functionality for comparators B and D. 0 Match on data bus equivalence to comparator register contents 1 Match on data bus difference to comparator register contents 6 SZ (Comparators B and D) Size Comparator Value Bit — The SZ bit selects either word or byte access size in comparison for the associated comparator. This bit is ignored if the SZE bit is cleared or if the TAG bit in the same register is set. This bit position has NDB functionality for comparators A and C 0 Word access size will be compared 1 Byte access size will be compared 5 Tag Select — This bit controls whether the comparator match will cause a trigger or tag the opcode at the TAG matched address. Tagged opcodes trigger only if they reach the execution stage of the instruction queue. 0 Trigger immediately on match 1 On match, tag the opcode. If the opcode is about to be executed a trigger is generated 4 BRK Break — This bit controls whether a channel match terminates a debug session immediately, independent of state sequencer state. To generate an immediate breakpoint the module breakpoints must be enabled using DBGBRK. 0 The debug session termination is dependent upon the state sequencer and trigger conditions. 1 A match on this channel terminates the debug session immediately; breakpoints if active are generated, tracing, if active, is terminated and the module disarmed. 3 Read/Write Comparator Value Bit — The RW bit controls whether read or write is used in compare for the RW associated comparator . The RW bit is not used if RWE = 0. 0 Write cycle will be matched 1 Read cycle will be matched 2 RWE Read/Write Enable Bit — The RWE bit controls whether read or write comparison is enabled for the associated comparator. This bit is not used for tagged operations. 0 Read/Write is not used in comparison 1 Read/Write is used in comparison S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 203 S12X Debug (S12XDBGV3) Module Table 6-27. DBGXCTL Field Descriptions (continued) Field 0 COMPE Description Determines if comparator is enabled 0 The comparator is not enabled 1 The comparator is enabled for state sequence triggers or tag generation Table 6-28 shows the effect for RWE and RW on the comparison conditions. These bits are not useful for tagged operations since the trigger occurs based on the tagged opcode reaching the execution stage of the instruction queue. Thus these bits are ignored if tagged triggering is selected. Table 6-28. Read or Write Comparison Logic Table RWE Bit 0 0 1 1 1 1 RW Bit x x 0 0 1 1 RW Signal 0 1 0 1 0 1 Comment RW not used in comparison RW not used in comparison Write No match No match Read 6.3.2.8.2 Debug Comparator Address High Register (DBGXAH) Address: 0x0029 7 R 0 W 6 Bit 22 5 Bit 21 4 Bit 20 Reset 0 0 0 0 = Unimplemented or Reserved 3 Bit 19 0 2 Bit 18 0 1 Bit 17 0 Figure 6-15. Debug Comparator Address High Register (DBGXAH) Read: Anytime. See Table 6-26 for visible register encoding. Write: If DBG not armed. See Table 6-26 for visible register encoding. 0 Bit 16 0 Table 6-29. DBGXAH Field Descriptions Field Description 6–0 Bit[22:16] Comparator Address High Compare Bits — The Comparator address high compare bits control whether the selected comparator will compare the address bus bits [22:16] to a logic one or logic zero. . 0 Compare corresponding address bit to a logic zero 1 Compare corresponding address bit to a logic one S12XS-Family Reference Manual, Rev. 1.03 204 PRELIMINARY Freescale Semiconductor 6.3.2.8.3 S12X Debug (S12XDBGV3) Module Debug Comparator Address Mid Register (DBGXAM) Address: 0x002A R W Reset 7 Bit 15 0 6 Bit 14 0 5 Bit 13 0 4 Bit 12 0 3 Bit 11 0 2 Bit 10 0 1 Bit 9 0 0 Bit 8 0 Figure 6-16. Debug Comparator Address Mid Register (DBGXAM) Read: Anytime. See Table 6-26 for visible register encoding. Write: If DBG not armed. See Table 6-26 for visible register encoding. Table 6-30. DBGXAM Field Descriptions Field 7–0 Bit[15:8] Description Comparator Address Mid Compare Bits— The Comparator address mid compare bits control whether the selected comparator will compare the address bus bits [15:8] to a logic one or logic zero. 0 Compare corresponding address bit to a logic zero 1 Compare corresponding address bit to a logic one 6.3.2.8.4 Debug Comparator Address Low Register (DBGXAL) Address: 0x002B R W Reset 7 Bit 7 0 6 Bit 6 0 5 Bit 5 0 4 Bit 4 0 3 Bit 3 0 2 Bit 2 0 1 Bit 1 0 0 Bit 0 0 Figure 6-17. Debug Comparator Address Low Register (DBGXAL) Read: Anytime. See Table 6-26 for visible register encoding. Write: If DBG not armed. See Table 6-26 for visible register encoding. Table 6-31. DBGXAL Field Descriptions Field 7–0 Bits[7:0] Description Comparator Address Low Compare Bits — The Comparator address low compare bits control whether the selected comparator will compare the address bus bits [7:0] to a logic one or logic zero. 0 Compare corresponding address bit to a logic zero 1 Compare corresponding address bit to a logic one S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 205 S12X Debug (S12XDBGV3) Module 6.3.2.8.5 Debug Comparator Data High Register (DBGXDH) Address: 0x002C R W Reset 7 Bit 15 0 6 Bit 14 0 5 Bit 13 0 4 Bit 12 0 3 Bit 11 0 2 Bit 10 0 1 Bit 9 0 0 Bit 8 0 Figure 6-18. Debug Comparator Data High Register (DBGXDH) Read: Anytime. See Table 6-26 for visible register encoding. Write: If DBG not armed. See Table 6-26 for visible register encoding. Table 6-32. DBGXAH Field Descriptions Field Description 7–0 Bits[15:8] Comparator Data High Compare Bits — The Comparator data high compare bits control whether the selected comparator compares the data bus bits [15:8] to a logic one or logic zero. The comparator data compare bits are only used in comparison if the corresponding data mask bit is logic 1. This register is available only for comparators A and C. 0 Compare corresponding data bit to a logic zero 1 Compare corresponding data bit to a logic one 6.3.2.8.6 Debug Comparator Data Low Register (DBGXDL) Address: 0x002D R W Reset 7 Bit 7 0 6 Bit 6 0 5 Bit 5 0 4 Bit 4 0 3 Bit 3 0 2 Bit 2 0 1 Bit 1 0 0 Bit 0 0 Figure 6-19. Debug Comparator Data Low Register (DBGXDL) Read: Anytime. See Table 6-26 for visible register encoding. Write: If DBG not armed. See Table 6-26 for visible register encoding. Table 6-33. DBGXDL Field Descriptions Field 7–0 Bits[7:0] Description Comparator Data Low Compare Bits — The Comparator data low compare bits control whether the selected comparator compares the data bus bits [7:0] to a logic one or logic zero. The comparator data compare bits are only used in comparison if the corresponding data mask bit is logic 1. This register is available only for comparators A and C. 0 Compare corresponding data bit to a logic zero 1 Compare corresponding data bit to a logic one S12XS-Family Reference Manual, Rev. 1.03 206 PRELIMINARY Freescale Semiconductor 6.3.2.8.7 S12X Debug (S12XDBGV3) Module Debug Comparator Data High Mask Register (DBGXDHM) Address: 0x002E R W Reset 7 Bit 15 0 6 Bit 14 0 5 Bit 13 0 4 Bit 12 0 3 Bit 11 0 2 Bit 10 0 1 Bit 9 0 0 Bit 8 0 Figure 6-20. Debug Comparator Data High Mask Register (DBGXDHM) Read: Anytime. See Table 6-26 for visible register encoding. Write: If DBG not armed. See Table 6-26 for visible register encoding. Table 6-34. DBGXDHM Field Descriptions Field Description 7–0 Bits[15:8] Comparator Data High Mask Bits — The Comparator data high mask bits control whether the selected comparator compares the data bus bits [15:8] to the corresponding comparator data compare bits. This register is available only for comparators A and C. 0 Do not compare corresponding data bit 1 Compare corresponding data bit 6.3.2.8.8 Debug Comparator Data Low Mask Register (DBGXDLM) Address: 0x002F R W Reset 7 Bit 7 0 6 Bit 6 0 5 Bit 5 0 4 Bit 4 0 3 Bit 3 0 2 Bit 2 0 1 Bit 1 0 0 Bit 0 0 Figure 6-21. Debug Comparator Data Low Mask Register (DBGXDLM) Read: Anytime. See Table 6-26 for visible register encoding. Write: If DBG not armed. See Table 6-26 for visible register encoding. Table 6-35. DBGXDLM Field Descriptions Field 7–0 Bits[7:0] Description Comparator Data Low Mask Bits — The Comparator data low mask bits control whether the selected comparator compares the data bus bits [7:0] to the corresponding comparator data compare bits. This register is available only for comparators A and C. 0 Do not compare corresponding data bit 1 Compare corresponding data bit 6.4 Functional Description This section provides a complete functional description of the S12XDBG module. If the part is in secure mode, the S12XDBG module can generate breakpoints but tracing is not possible. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 207 S12X Debug (S12XDBGV3) Module 6.4.1 S12XDBG Operation Arming the S12XDBG module by setting ARM in DBGC1 allows triggering, and storing of data in the trace buffer and can be used to cause breakpoints to the CPU12X . The DBG module is made up of four main blocks, the comparators, control logic, the state sequencer, and the trace buffer. The comparators monitor the bus activity of the CPU12X . Comparators can be configured to monitor address and databus. Comparators can also be configured to mask out individual data bus bits during a compare and to use R/W and word/byte access qualification in the comparison. When a match with a comparator register value occurs the associated control logic can trigger the state sequencer to another state (see Figure 6-22). Either forced or tagged triggers are possible. Using a forced trigger, the trigger is generated immediately on a comparator match. Using a tagged trigger, at a comparator match, the instruction opcode is tagged and only if the instruction reaches the execution stage of the instruction queue is a trigger generated. In the case of a transition to Final State, bus tracing is triggered and/or a breakpoint can be generated. Independent of the state sequencer, a breakpoint can be triggered by writing to the TRIG bit in the DBGC1 control register. The trace buffer is visible through a 2-byte window in the register address map and can be read out using standard 16-bit word reads. 6.4.2 Comparator Modes The S12XDBG contains four comparators, A, B, C, and D. Each comparator compares the selected address bus with the address stored in DBGXAH, DBGXAM, and DBGXAL. Furthermore, comparators A and C also compare the data buses to the data stored in DBGXDH, DBGXDL and allow masking of individual data bus bits. S12X comparator matches are disabled in BDM and during BDM accesses. The comparator match control logic configures comparators to monitor the buses for an exact address or an address range. The comparator configuration is controlled by the control register contents and the range control by the DBGC2 contents. On a match a trigger can initiate a transition to another state sequencer state (see Section 6.4.3”). The comparator control register also allows the type of access to be included in the comparison through the use of the RWE, RW, SZE, and SZ bits. The RWE bit controls whether read or write comparison is enabled for the associated comparator and the RW bit selects either a read or write access for a valid match. Similarly the SZE and SZ bits allows the size of access (word or byte) to be considered in the compare. Only comparators B and D feature SZE and SZ. The TAG bit in each comparator control register is used to determine the triggering condition. By setting TAG, the comparator will qualify a match with the output of opcode tracking logic and a trigger occurs before the tagged instruction executes (tagged-type trigger). Whilst tagging, the RW, RWE, SZE, and SZ bits are ignored and the comparator register must be loaded with the exact opcode address. If the TAG bit is clear (forced type trigger) a comparator match is generated when the selected address appears on the system address bus. If the selected address is an opcode address, the match is generated S12XS-Family Reference Manual, Rev. 1.03 208 PRELIMINARY Freescale Semiconductor S12X Debug (S12XDBGV3) Module when the opcode is fetched from the memory. This precedes the instruction execution by an indefinite number of cycles due to instruction pipe lining. For a comparator match of an opcode at an odd address when TAG = 0, the corresponding even address must be contained in the comparator register. Thus for an opcode at odd address (n), the comparator register must contain address (n–1). Once a successful comparator match has occurred, the condition that caused the original match is not verified again on subsequent matches. Thus if a particular data value is verified at a given address, this address may not still contain that data value when a subsequent match occurs. Comparators C and D can also be used to select an address range to trace from. This is determined by the TRANGE bits in the DBGTCR register. The TRANGE encoding is shown in Table 6-9. If the TRANGE bits select a range definition using comparator D, then comparator D is configured for trace range definition and cannot be used for address bus comparisons. Similarly if the TRANGE bits select a range definition using comparator C, then comparator C is configured for trace range definition and cannot be used for address bus comparisons. Match[0, 1, 2, 3] map directly to Comparators[A, B, C, D] respectively, except in range modes (see Section 6.3.2.4”). Comparator priority rules are described in the trigger priority section (Section 6.4.3.4”). 6.4.2.1 Exact Address Comparator Match (Comparators A and C) With range comparisons disabled, the match condition is an exact equivalence of address/data bus with the value stored in the comparator address/data registers. Further qualification of the type of access (R/W, word/byte) is possible. Comparators A and C do not feature SZE or SZ control bits, thus the access size is not compared. Table 637 lists access considerations without data bus compare. Table 6-36 lists access considerations with data bus comparison. To compare byte accesses DBGxDH must be loaded with the data byte, the low byte must be masked out using the DBGxDLM mask register. On word accesses the data byte of the lower address is mapped to DBGxDH. Table 6-36. Comparator A and C Data Bus Considerations Access Word Byte Word Word Address ADDR[n] ADDR[n] ADDR[n] ADDR[n] DBGxDH Data[n] Data[n] Data[n] x DBGxDL Data[n+1] x x Data[n+1] DBGxDHM $FF $FF $FF $00 DBGxDLM $FF $00 $00 $FF Example Valid Match MOVW #$WORD ADDR[n] MOVB #$BYTE ADDR[n] MOVW #$WORD ADDR[n] MOVW #$WORD ADDR[n] config1 config2 config2 config3 Code may contain various access forms of the same address, i.e. a word access of ADDR[n] or byte access of ADDR[n+1] both access n+1. At a word access of ADDR[n], address ADDR[n+1] does not appear on the address bus and so cannot cause a comparator match if the comparator contains ADDR[n]. Thus it is not possible to monitor all data accesses of ADDR[n+1] with one comparator. To detect an access of ADDR[n+1] through a word access of ADDR[n] the comparator can be configured to ADDR[n], DBGxDL is loaded with the data pattern and DBGxDHM is cleared so only the data[n+1] is compared on accesses of ADDR[n]. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 209 S12X Debug (S12XDBGV3) Module NOTE Using this configuration, a byte access of ADDR[n] can cause a comparator match if the databus low byte by chance contains the same value as ADDR[n+1] because the databus comparator does not feature access size comparison and uses the mask as a “don’t care” function. Thus masked bits do not prevent a match. Comparators A and C feature an NDB control bit to determine if a match occurs when the data bus differs to comparator register contents or when the data bus is equivalent to the comparator register contents. 6.4.2.2 Exact Address Comparator Match (Comparators B and D) Comparators B and D feature SZ and SZE control bits. If SZE is clear, then the comparator address match qualification functions the same as for comparators A and C. If the SZE bit is set the access size (word or byte) is compared with the SZ bit value such that only the specified type of access causes a match. Thus if configured for a byte access of a particular address, a word access covering the same address does not lead to match. Table 6-37. Comparator Access Size Considerations Comparator Comparators A and C Comparators B and D Comparators B and D Address ADDR[n] SZE SZ8 —— ADDR[n] 0 X ADDR[n] 1 0 Condition For Valid Match Word and byte accesses of ADDR[n]1 MOVB #$BYTE ADDR[n] MOVW #$WORD ADDR[n] Word and byte accesses of ADDR[n]1 MOVB #$BYTE ADDR[n] MOVW #$WORD ADDR[n] Word accesses of ADDR[n]1 MOVW #$WORD ADDR[n] Comparators ADDR[n] 1 1 Byte accesses of ADDR[n] B and D MOVB #$BYTE ADDR[n] 1 A word access of ADDR[n-1] also accesses ADDR[n] but does not generate a match. The comparator address register must contain the exact address used in the code. 6.4.2.3 Data Bus Comparison NDB Dependency Comparators A and C each feature an NDB control bit, which allows data bus comparators to be configured to either trigger on equivalence or trigger on difference. This allows monitoring of a difference in the contents of an address location from an expected value. When matching on an equivalence (NDB=0), each individual data bus bit position can be masked out by clearing the corresponding mask bit (DBGxDHM/DBGxDLM), so that it is ignored in the comparison. A match occurs when all data bus bits with corresponding mask bits set are equivalent. If all mask register bits are clear, then a match is based on the address bus only, the data bus is ignored. When matching on a difference, mask bits can be cleared to ignore bit positions. A match occurs when any data bus bit with corresponding mask bit set is different. Clearing all mask bits, causes all bits to be ignored and prevents a match because no difference can be detected. In this case address bus equivalence does not cause a match. S12XS-Family Reference Manual, Rev. 1.03 210 PRELIMINARY Freescale Semiconductor S12X Debug (S12XDBGV3) Module NDB 0 0 1 1 Table 6-38. NDB and MASK bit dependency DBGxDHM[n] / DBGxDLM[n] 0 1 0 1 Comment Do not compare data bus bit. Compare data bus bit. Match on equivalence. Do not compare data bus bit. Compare data bus bit. Match on difference. 6.4.2.4 Range Comparisons When using the AB comparator pair for a range comparison, the data bus can also be used for qualification by using the comparator A data and data mask registers. Furthermore the DBGACTL RW and RWE bits can be used to qualify the range comparison on either a read or a write access. The corresponding DBGBCTL bits are ignored. Similarly when using the CD comparator pair for a range comparison, the data bus can also be used for qualification by using the comparator C data and data mask registers. Furthermore the DBGCCTL RW and RWE bits can be used to qualify the range comparison on either a read or a write access if tagging is not selected. The corresponding DBGDCTL bits are ignored. The SZE and SZ control bits are ignored in range mode. The comparator A and C TAG bits are used to tag range comparisons for the AB and CD ranges respectively. The comparator B and D TAG bits are ignored in range modes. In order for a range comparison using comparators A and B, both COMPEA and COMPEB must be set; to disable range comparisons both must be cleared. Similarly for a range CD comparison, both COMPEC and COMPED must be set. The comparator A and C BRK bits are used for the AB and CD ranges respectively, the comparator B and D BRK bits are ignored in range mode. When configured for range comparisons and tagging, the ranges are accurate only to word boundaries. 6.4.2.4.1 Inside Range (CompAC_Addr ≤ address ≤ CompBD_Addr) In the Inside Range comparator mode, either comparator pair A and B or comparator pair C and D can be configured for range comparisons by the control register (DBGC2). The match condition requires that a valid match for both comparators happens on the same bus cycle. A match condition on only one comparator is not valid. An aligned word access which straddles the range boundary will cause a trigger only if the aligned address is inside the range. 6.4.2.4.2 Outside Range (address < CompAC_Addr or address > CompBD_Addr) In the Outside Range comparator mode, either comparator pair A and B or comparator pair C and D can be configured for range comparisons. A single match condition on either of the comparators is recognized as valid. An aligned word access which straddles the range boundary will cause a trigger only if the aligned address is outside the range. Outside range mode in combination with tagged triggers can be used to detect if the opcode fetches are from an unexpected range. In forced trigger modes the outside range trigger would typically be activated at any interrupt vector fetch or register access. This can be avoided by setting the upper or lower range limit to $7FFFFF or $000000 respectively. Interrupt vector fetches do not cause taghits S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 211 S12X Debug (S12XDBGV3) Module 6.4.3 Trigger Modes Trigger modes are used as qualifiers for a state sequencer change of state. The control logic determines the trigger mode and provides a trigger to the state sequencer. The individual trigger modes are described in the following sections. 6.4.3.1 Forced Trigger On Comparator Match If a forced trigger comparator match occurs, the trigger immediately initiates a transition to the next state sequencer state whereby the corresponding flags in DBGSR are set. The state control register for the current state determines the next state for each trigger. Forced triggers are generated as soon as the matching address appears on the address bus, which in the case of opcode fetches occurs several cycles before the opcode execution. For this reason a forced trigger at an opcode address precedes a tagged trigger at the same address by several cycles. 6.4.3.2 Trigger On Comparator Related Taghit If a CPU12X taghit occurs, a transition to another state sequencer state is initiated and the corresponding DBGSR flags are set. For a comparator related taghit to occur, the S12XDBG must first generate tags based on comparator matches. When the tagged instruction reaches the execution stage of the instruction queue a taghit is generated by the CPU12X. The state control register for the current state determines the next state for each trigger. 6.4.3.3 TRIG Immediate Trigger Independent of comparator matches it is possible to initiate a tracing session and/or breakpoint by writing the TRIG bit in DBGC1 to a logic “1”. If configured for begin or mid aligned tracing, this triggers the state sequencer into the Final State, if configured for end alignment, setting the TRIG bit disarms the module, ending the session. If breakpoints are enabled, a forced breakpoint request is issued immediately (end alignment) or when tracing has completed (begin or mid alignment). 6.4.3.4 Trigger Priorities In case of simultaneous triggers, the priority is resolved according to Table 6-39. The lower priority trigger is suppressed. It is thus possible to miss a lower priority trigger if it occurs simultaneously with a trigger of a higher priority. The trigger priorities described in Table 6-39 dictate that in the case of simultaneous matches, the match on the lower channel number (0,1,2,3) has priority. The SC[3:0] encoding ensures that a match leading to final state has priority over all other matches in each state sequencer state. When configured for range modes a simultaneous match of comparators A and C generates an active match0 whilst match2 is suppressed. If a write access to DBGC1 with the ARM bit position set occurs simultaneously to a hardware disarm from an internal trigger event, then the ARM bit is cleared due to the hardware disarm. Priority Source Table 6-39. Trigger Priorities Action S12XS-Family Reference Manual, Rev. 1.03 212 PRELIMINARY Freescale Semiconductor Highest Lowest S12X Debug (S12XDBGV3) Module Table 6-39. Trigger Priorities TRIG Match0 (force or tag hit) Match1 (force or tag hit) Match2 (force or tag hit) Match3 (force or tag hit) Trigger immediately to final state (begin or mid aligned tracing enabled) Trigger immediately to state 0 (end aligned or no tracing enabled) Trigger to next state as defined by state control registers Trigger to next state as defined by state control registers Trigger to next state as defined by state control registers Trigger to next state as defined by state control registers 6.4.4 State Sequence Control 状态顺序控制图 ARM = 0 State 0 (Disarmed) ARM = 1 ARM = 0 State1 State2 ARM = 0 Session Complete (Disarm) Final State State3 Figure 6-22. State Sequencer Diagram The state sequencer allows a defined sequence of events to provide a trigger point for tracing of data in the trace buffer. Once the S12XDBG module has been armed by setting the ARM bit in the DBGC1 register, then state1 of the state sequencer is entered. Further transitions between the states are then controlled by the state control registers and depend upon a selected trigger mode condition being met. From Final State the only permitted transition is back to the disarmed state0. Transition between any of the states 1 to 3 is not restricted. Each transition updates the SSF[2:0] flags in DBGSR accordingly to indicate the current state. Alternatively by setting the TRIG bit in DBGSC1, the state machine can be triggered to state0 or Final State depending on tracing alignment. Independent of the state sequencer, each comparator channel can be individually configured to generate an immediate breakpoint when a match occurs through the use of the BRK bits in the DBGxCTL registers. Thus it is possible to generate an immediate breakpoint on selected channels, whilst a state sequencer transition can be initiated by a match on other channels. If a debug session is ended by a trigger on a channel with BRK = 1, the state sequencer transitions through Final State for a clock cycle to state0. This is independent of tracing and breakpoint activity, thus with tracing and breakpoints disabled, the state sequencer enters state0 and the debug module is disarmed. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 213 S12X Debug (S12XDBGV3) Module 6.4.4.1 Final State On entering Final State a trigger may be issued to the trace buffer according to the trace position control as defined by the TALIGN field (see Section 6.3.2.3”). If TSOURCE in the trace control register DBGTCR is cleared then the trace buffer is disabled and the transition to Final State can only generate a breakpoint request. In this case or upon completion of a tracing session when tracing is enabled, the ARM bit in the DBGC1 register is cleared, returning the module to the disarmed state0. If tracing is enabled, a breakpoint request can occur at the end of the tracing session. If neither tracing nor breakpoints are enabled then when the final state is reached it returns automatically to state0 and the debug module is disarmed. 6.4.5 Trace Buffer Operation The trace buffer is a 64 lines deep by 64-bits wide RAM array. The S12XDBG module stores trace information in the RAM array in a circular buffer format. The RAM array can be accessed through a register window (DBGTBH:DBGTBL) using 16-bit wide word accesses. After each complete 64-bit trace buffer line is read, an internal pointer into the RAM is incremented so that the next read will receive fresh information. Data is stored in the format shown in Table 6-40. After each store the counter register bits DBGCNT[6:0] are incremented. Tracing of CPU12X activity is disabled when the BDM is active. Reading the trace buffer whilst the DBG is armed returns invalid data and the trace buffer pointer is not incremented. 6.4.5.1 Trace Trigger Alignment Using the TALIGN bits (see Section 6.3.2.3”) it is possible to align the trigger with the end, the middle, or the beginning of a tracing session. If End or Mid tracing is selected, tracing begins when the ARM bit in DBGC1 is set and State1 is entered. The transition to Final State if End is selected signals the end of the tracing session. The transition to Final State if Mid is selected signals that another 32 lines will be traced before ending the tracing session. Tracing with Begin-Trigger starts at the opcode of the trigger. 6.4.5.1.1 Storing with Begin-Trigger Storing with Begin-Trigger, data is not stored in the Trace Buffer until the Final State is entered. Once the trigger condition is met the S12XDBG module will remain armed until 64 lines are stored in the Trace Buffer. If the trigger is at the address of the change-of-flow instruction the change of flow associated with the trigger will be stored in the Trace Buffer. Using Begin-trigger together with tagging, if the tagged instruction is about to be executed then the trace is started. Upon completion of the tracing session the breakpoint is generated, thus the breakpoint does not occur at the tagged instruction boundary. 6.4.5.1.2 Storing with Mid-Trigger Storing with Mid-Trigger, data is stored in the Trace Buffer as soon as the S12XDBG module is armed. When the trigger condition is met, another 32 lines will be traced before ending the tracing session, irrespective of the number of lines stored before the trigger occurred, then the S12XDBG module is disarmed and no more data is stored. Using Mid-trigger with tagging, if the tagged instruction is about to S12XS-Family Reference Manual, Rev. 1.03 214 PRELIMINARY Freescale Semiconductor S12X Debug (S12XDBGV3) Module be executed then the trace is continued for another 32 lines. Upon tracing completion the breakpoint is generated, thus the breakpoint does not occur at the tagged instruction boundary. 6.4.5.1.3 Storing with End-Trigger Storing with End-Trigger, data is stored in the Trace Buffer until the Final State is entered, at which point the S12XDBG module will become disarmed and no more data will be stored. If the trigger is at the address of a change of flow instruction the trigger event will not be stored in the Trace Buffer. 6.4.5.2 Trace Modes The S12XDBG module can operate in four trace modes. The mode is selected using the TRCMOD bits in the DBGTCR register. The modes are described in the following subsections. The trace buffer organization is shown in Table 6-40. 6.4.5.2.1 Normal Mode In Normal Mode, change of flow (COF) program counter (PC) addresses will be stored. COF addresses are defined as follows : • Source address of taken conditional branches (long, short, bit-conditional, and loop primitives) • Destination address of indexed JMP, JSR, and CALL instruction • Destination address of RTI, RTS, and RTC instructions. • Vector address of interrupts, except for SWI and BDM vectors LBRA, BRA, BSR, BGND as well as non-indexed JMP, JSR, and CALL instructions are not classified as change of flow and are not stored in the trace buffer. Change-of-flow addresses stored include the full 23-bit address bus of CPU12X and an information byte, which contains a source/destination bit to indicate whether the stored address was a source address or destination address. NOTE When an CPU12X COF instruction with destination address is executed, the destination address is stored to the trace buffer on instruction completion, indicating the COF has taken place. If an interrupt occurs simultaneously then the next instruction carried out is actually from the interrupt service routine. The instruction at the destination address of the original program flow gets exectuted after the interrupt service routine. In the following example an IRQ interrupt occurs during execution of the indexed JMP at address MARK1. The BRN at the destination (SUB_1) is not executed until after the IRQ service routine but the destination address is entered into the trace buffer to indicate that the indexed JMP COF has taken place. LDX MARK1 JMP MARK2 NOP #SUB_1 0,X ; IRQ interrupt occurs during execution of this ; S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 215 S12X Debug (S12XDBGV3) Module SUB_1 ADDR1 BRN NOP DBNE * A,PART5 ; JMP Destination address TRACE BUFFER ENTRY 1 ; RTI Destination address TRACE BUFFER ENTRY 3 ; ; Source address TRACE BUFFER ENTRY 4 IRQ_ISR LDAB #$F0 ; IRQ Vector $FFF2 = TRACE BUFFER ENTRY 2 STAB VAR_C1 RTI ; The execution flow taking into account the IRQ is as follows LDX #SUB_1 MARK1 JMP 0,X ; IRQ_ISR LDAB #$F0 ; STAB VAR_C1 RTI ; SUB_1 BRN * NOP ; ADDR1 DBNE A,PART5 ; 6.4.5.2.2 Loop1 Mode Loop1 Mode, similarly to Normal Mode also stores only COF address information to the trace buffer, it however allows the filtering out of redundant information. The intent of Loop1 Mode is to prevent the Trace Buffer from being filled entirely with duplicate information from a looping construct such as delays using the DBNE instruction or polling loops using BRSET/BRCLR instructions. Immediately after address information is placed in the Trace Buffer, the S12XDBG module writes this value into a background register. This prevents consecutive duplicate address entries in the Trace Buffer resulting from repeated branches. Loop1 Mode only inhibits consecutive duplicate source address entries that would typically be stored in most tight looping constructs. It does not inhibit repeated entries of destination addresses or vector addresses, since repeated entries of these would most likely indicate a bug in the user’s code that the S12XDBG module is designed to help find. 6.4.5.2.3 Detail Mode In Detail Mode, address and data for all memory and register accesses is stored in the trace buffer. This mode also features information byte entries to the trace buffer, for each address byte entry. The information byte indicates the size of access (word or byte) and the type of access (read or write). When tracing CPU12X activity in Detail Mode, all cycles are traced except those when the CPU12X is either in a free or opcode fetch cycle, the address range can be limited to a range specified by the TRANGE bits in DBGTCR. This function uses comparators C and D to define an address range inside which CPU12X activity should be traced (see Table 6-40). Thus the traced CPU12X activity can be restricted to particular register range accesses. 6.4.5.2.4 Pure PC Mode In Pure PC Mode, tracing from the CPU the PC addresses of all executed opcodes, including illegal opcodes, are stored. S12XS-Family Reference Manual, Rev. 1.03 216 PRELIMINARY Freescale Semiconductor S12X Debug (S12XDBGV3) Module 6.4.5.3 Trace Buffer Organization Referring to Table 6-40. ADRH, ADRM, ADRL denote address high, middle and low byte respectively. INF bytes contain control information (R/W, S/D etc.). The numerical suffix indicates which tracing step. The information format for Loop1 Mode and PurePC Mode is the same as that of Normal Mode. Whilst tracing in Normal or Loop1 modes each array line contains 2 data entries, thus in this case the DBGCNT[0] is incremented after each separate entry. In Detail mode DBGCNT[0] remains cleared whilst the other DBGCNT bits are incremented on each trace buffer entry. When a COF occurs a trace buffer entry is made and the corresponding CDV bit is set. Single byte data accesses in Detail Mode are always stored to the low byte of the trace buffer (CDATAL ) and the high byte is cleared. When tracing word accesses, the byte at the lower address is always stored to trace buffer byte3 and the byte at the higher address is stored to byte2 Table 6-40. Trace Buffer Organization 8-Byte Wide Word Buffer Mode 7 6 5 4 3 2 1 0 S12XCPU Detail CXINF1 CXINF2 CADRH1 CADRH2 CADRM1 CADRM2 CADRL1 CADRL2 CDATAH1 CDATAL1 CDATAH2 CDATAL2 CPU12X Other Modes CINF1 CINF3 CPCH1 CPCH3 CPCM1 CPCM3 CPCL1 CPCL3 CINF0 CINF2 CPCH0 CPCH2 CPCM0 CPCM2 CPCL0 CPCL2 S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 217 S12X Debug (S12XDBGV3) Module 6.4.5.3.1 Information Byte Organization The format of the control information byte is dependent upon the active trace mode as described below. In Normal, Loop1, or Pure PC modes tracing of CPU12X activity, CINF is used to store control information. In Detail Mode, CXINF contains the control information CPU12X Information Byte Field 7 CSD 6 CVA 4 CDV Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 CSD CVA 0 CDV 0 0 0 0 Figure 6-23. CPU12X Information Byte CINF Table 6-41. CINF Field Descriptions Description Source Destination Indicator — This bit indicates if the corresponding stored address is a source or destination address. This is only used in Normal and Loop1 mode tracing. 0 Source address 1 Destination address Vector Indicator — This bit indicates if the corresponding stored address is a vector address.. Vector addresses are destination addresses, thus if CVA is set, then the corresponding CSD is also set. This is only used in Normal and Loop1 mode tracing. This bit has no meaning in Pure PC mode. 0 Indexed jump destination address 1 Vector destination address Data Invalid Indicator — This bit indicates if the trace buffer entry is invalid. It is only used when tracing from both sources in Normal, Loop1 and Pure PC modes, to indicate that the CPU12X trace buffer entry is valid. 0 Trace buffer entry is invalid 1 Trace buffer entry is valid CXINF Information Byte Bit 7 Bit 6 CSZ Bit 5 CRW Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Figure 6-24. Information Byte CXINF This describes the format of the information byte used only when tracing in Detail Mode. When tracing from the CPU12X in Detail Mode, information is stored to the trace buffer on all cycles except opcode fetch and free cycles. In this case the CSZ and CRW bits indicate the type of access being made by the CPU12X. Table 6-42. CXINF Field Descriptions Field 6 CSZ Description Access Type Indicator — This bit indicates if the access was a byte or word size access.This bit only contains valid information when tracing CPU12X activity in Detail Mode. 0 Word Access 1 Byte Access S12XS-Family Reference Manual, Rev. 1.03 218 PRELIMINARY Freescale Semiconductor Field 5 CRW S12X Debug (S12XDBGV3) Module Table 6-42. CXINF Field Descriptions (continued) Description Read Write Indicator — This bit indicates if the corresponding stored address corresponds to a read or write access. This bit only contains valid information when tracing CPU12X activity in Detail Mode. 0 Write Access 1 Read Access 6.4.5.4 Reading Data from Trace Buffer The data stored in the Trace Buffer can be read using either the background debug module (BDM) module or the CPU12X provided the S12XDBG module is not armed, is configured for tracing and the system not secured. When the ARM bit is written to 1 the trace buffer is locked to prevent reading. The trace buffer can only be unlocked for reading by an aligned word write to DBGTB when the module is disarmed. The Trace Buffer can only be read through the DBGTB register using aligned word reads, any byte or misaligned reads return 0 and do not cause the trace buffer pointer to increment to the next trace buffer address. The Trace Buffer data is read out first-in first-out. By reading CNT in DBGCNT the number of valid 64-bit lines can be determined. DBGCNT will not decrement as data is read. Whilst reading an internal pointer is used to determine the next line to be read. After a tracing session, the pointer points to the oldest data entry, thus if no overflow has occurred, the pointer points to line0, otherwise it points to the line with the oldest entry. The pointer is initialized by each aligned write to DBGTBH to point to the oldest data again. This enables an interrupted trace buffer read sequence to be easily restarted from the oldest data entry. The least significant word of each 64-bit wide array line is read out first. This corresponds to the bytes 1 and 0 of Table 6-40. The bytes containing invalid information (shaded in Table 6-40) are also read out. Reading the Trace Buffer while the S12XDBG module is armed will return invalid data and no shifting of the RAM pointer will occur. 6.4.5.5 Trace Buffer Reset State The Trace Buffer contents are not initialized by a system reset. Thus should a system reset occur, the trace session information from immediately before the reset occurred can be read out. The DBGCNT bits are not cleared by a system reset. Thus should a reset occur, the number of valid lines in the trace buffer is indicated by DBGCNT. The internal pointer to the current trace buffer address is initialized by unlocking the trace buffer thus points to the oldest valid data even if a reset occurred during the tracing session. Generally debugging occurrences of system resets is best handled using mid or end trigger alignment since the reset may occur before the trace trigger, which in the begin trigger alignment case means no information would be stored in the trace buffer. NOTE An external pin RESET that occurs simultaneous to a trace buffer entry can, in very seldom cases, lead to either that entry being corrupted or the first entry of the session being corrupted. In such cases the other contents of the trace buffer still contain valid tracing information. The case occurs when the reset assertion coincides with the trace buffer entry clock edge. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 219 S12X Debug (S12XDBGV3) Module 6.4.6 Tagging A tag follows program information as it advances through the instruction queue. When a tagged instruction reaches the head of the queue a tag hit occurs and triggers the state sequencer. Each comparator control register features a TAG bit, which controls whether the comparator match will cause a trigger immediately or tag the opcode at the matched address. If a comparator is enabled for tagged comparisons, the address stored in the comparator match address registers must be an opcode address for the trigger to occur. Using Begin trigger together with tagging, if the tagged instruction is about to be executed then the transition to the next state sequencer state occurs. If the transition is to the Final State, tracing is started. Only upon completion of the tracing session can a breakpoint be generated. Similarly using Mid trigger with tagging, if the tagged instruction is about to be executed then the trace is continued for another 32 lines. Upon tracing completion the breakpoint is generated. Using End trigger, when the tagged instruction is about to be executed and the next transition is to Final State then a breakpoint is generated immediately, before the tagged instruction is carried out. Read/Write (R/W), access size (SZ) monitoring and data bus monitoring is not useful if tagged triggering is selected, since the tag is attached to the opcode at the matched address and is not dependent on the data bus nor on the type of access. Thus these bits are ignored if tagged triggering is selected. When configured for range comparisons and tagging, the ranges are accurate only to word boundaries. S12X tagging is disabled when the BDM becomes active. 6.4.7 Breakpoints Breakpoints can be generated as follows. • From comparator channel triggers to final state. • Using software to write to the TRIG bit in the DBGC1 register. Breakpoints generated via the BDM BACKGROUND command have no affect on the CPU12X in STOP or WAIT mode. 6.4.7.1 Breakpoints From Internal Comparator Channel Final State Triggers Breakpoints can be generated when internal comparator channels trigger the state sequencer to the Final State. If configured for tagging, then the breakpoint is generated when the tagged opcode reaches the execution stage of the instruction queue. If a tracing session is selected by TSOURCE, breakpoints are requested when the tracing session has completed, thus if Begin or Mid aligned triggering is selected, the breakpoint is requested only on completion of the subsequent trace (see Table 6-43). If no tracing session is selected, breakpoints are requested immediately. If the BRK bit is set on the triggering channel, then the breakpoint is generated immediately independent of tracing trigger alignment. S12XS-Family Reference Manual, Rev. 1.03 220 PRELIMINARY Freescale Semiconductor S12X Debug (S12XDBGV3) Module BRK 0 0 0 0 0 0 1 1 x TALIGN 00 00 01 01 10 10 00,01,10 00,01,10 11 Table 6-43. Breakpoint Setup DBGBRK 0 1 0 1 0 1 1 0 x Breakpoint Alignment Fill Trace Buffer until trigger (no breakpoints — keep running) Fill Trace Buffer until trigger, then breakpoint request occurs Start Trace Buffer at trigger (no breakpoints — keep running) Start Trace Buffer at trigger A breakpoint request occurs when Trace Buffer is full Store a further 32 Trace Buffer line entries after trigger (no breakpoints — keep running) Store a further 32 Trace Buffer line entries after trigger Request breakpoint after the 32 further Trace Buffer entries Terminate tracing and generate breakpoint immediately on trigger Terminate tracing immediately on trigger Reserved 6.4.7.2 Breakpoints Generated Via The TRIG Bit If a TRIG triggers occur, the Final State is entered. If a tracing session is selected by TSOURCE, breakpoints are requested when the tracing session has completed, thus if Begin or Mid aligned triggering is selected, the breakpoint is requested only on completion of the subsequent trace (see Table 6-43). If no tracing session is selected, breakpoints are requested immediately. TRIG breakpoints are possible even if the S12XDBG module is disarmed. 6.4.7.3 S12XDBG Breakpoint Priorities If a TRIG trigger occurs after Begin or Mid aligned tracing has already been triggered by a comparator instigated transition to Final State, then TRIG no longer has an effect. When the associated tracing session is complete, the breakpoint occurs. Similarly if a TRIG is followed by a subsequent trigger from a comparator channel, it has no effect, since tracing has already started. 6.4.7.3.1 S12XDBG Breakpoint Priorities And BDM Interfacing Breakpoint operation is dependent on the state of the S12XBDM module. If the S12XBDM module is active, the CPU12X is executing out of BDM firmware and S12X breakpoints are disabled. In addition, while executing a BDM TRACE command, tagging into BDM is disabled. If BDM is not active, the breakpoint will give priority to BDM requests over SWI requests if the breakpoint coincides with a SWI instruction in the user’s code. On returning from BDM, the SWI from user code gets executed. DBGBRK (DBGC1[3]) 0 1 1 Table 6-44. Breakpoint Mapping Summary BDM Bit (DBGC1[4]) X 0 0 BDM Enabled X X X BDM Active X 0 1 S12X Breakpoint Mapping No Breakpoint Breakpoint to SWI No Breakpoint S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 221 S12X Debug (S12XDBGV3) Module Table 6-44. Breakpoint Mapping Summary 1 1 0 X Breakpoint to SWI 1 1 1 0 Breakpoint to BDM 1 1 1 1 No Breakpoint BDM cannot be entered from a breakpoint unless the ENABLE bit is set in the BDM. If entry to BDM via a BGND instruction is attempted and the ENABLE bit in the BDM is cleared, the CPU12X actually executes the BDM firmware code. It checks the ENABLE and returns if ENABLE is not set. If not serviced by the monitor then the breakpoint is re-asserted when the BDM returns to normal CPU12X flow. If the comparator register contents coincide with the SWI/BDM vector address then an SWI in user code and DBG breakpoint could occur simultaneously. The CPU12X ensures that BDM requests have a higher priority than SWI requests. Returning from the BDM/SWI service routine care must be taken to avoid re triggering a breakpoint. NOTE When program control returns from a tagged breakpoint using an RTI or BDM GO command without program counter modification it will return to the instruction whose tag generated the breakpoint. To avoid re triggering a breakpoint at the same location reconfigure the S12XDBG module in the SWI routine, if configured for an SWI breakpoint, or over the BDM interface by executing a TRACE command before the GO to increment the program flow past the tagged instruction. S12XS-Family Reference Manual, Rev. 1.03 222 PRELIMINARY Freescale Semiconductor Chapter 7 Security (S12XS9SECV2) Version Number 02.00 02.01 02.02 Revision Date 27 Aug 2004 21 Feb 2007 19 Apr 2007 Effective Date 08 Sep 2004 21 Feb 2007 19 Apr 2007 Table 7-1. Revision History Author Description of Changes reviewed and updated for S12XD architecture added S12XE, S12XF and S12XS architectures corrected statement about Backdoor key access via BDM on XE, XF, XS 7.1 Introduction This specification describes the function of the security mechanism in the S12XS chip family (9SEC). NOTE No security feature is absolutely secure. However, Freescale’s strategy is to make reading or copying the FLASH and/or EEPROM difficult for unauthorized users. 7.1.1 Features The user must be reminded that part of the security must lie with the application code. An extreme example would be application code that dumps the contents of the internal memory. This would defeat the purpose of security. At the same time, the user may also wish to put a backdoor in the application program. An example of this is the user downloads a security key through the SCI, which allows access to a programming routine that updates parameters stored in another section of the Flash memory. The security features of the S12XS chip family (in secure mode) are: • Protect the content of non-volatile memories (Flash, EEPROM) • Execution of NVM commands is restricted • Disable access to internal memory via background debug module (BDM) Table 7-2 gives an overview over availability of security relevant features in unsecure and secure modes. Table 7-2. Feature Availability in Unsecure and Secure Modes on S12XS Unsecure Mode Secure Mode Flash Array Access NS SS NX ES EX ST NS SS NX ES EX ST ✔✔ ✔✔ S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 223 Security (S12XS9SECV2) Table 7-2. Feature Availability in Unsecure and Secure Modes on S12XS Unsecure Mode Secure Mode NS SS NX ES EX ST NS SS NX ES EX ST EEPROM Array Access ✔ ✔ NVM Commands ✔1 ✔ BDM ✔✔ ✔✔ ✔1 ✔1 — ✔2 DBG Module Trace ✔✔ —— 1 Restricted NVM command set only. Please refer to the NVM wrapper block guides for detailed information. 2 BDM hardware commands restricted to peripheral registers only. 7.1.2 Modes of Operation 7.1.3 Securing the Microcontroller Once the user has programmed the Flash and EEPROM, the chip can be secured by programming the security bits located in the options/security byte in the Flash memory array. These non-volatile bits will keep the device secured through reset and power-down. The options/security byte is located at address 0xFF0F (= global address 0x7F_FF0F) in the Flash memory array. This byte can be erased and programmed like any other Flash location. Two bits of this byte are used for security (SEC[1:0]). On devices which have a memory page window, the Flash options/security byte is also available at address 0xBF0F by selecting page 0x3F with the PPAGE register. The contents of this byte are copied into the Flash security register (FSEC) during a reset sequence. 7 6 0xFF0F KEYEN1 KEYEN0 5 NV5 4 NV4 3 NV3 2 NV2 Figure 7-1. Flash Options/Security Byte 1 SEC1 0 SEC0 The meaning of the bits KEYEN[1:0] is shown in Table 7-3. Please refer to Section 7.1.5.1, “Unsecuring the MCU Using the Backdoor Key Access” for more information. Table 7-3. Backdoor Key Access Enable Bits KEYEN[1:0] 00 01 10 11 Backdoor Key Access Enabled 0 (disabled) 0 (disabled) 1 (enabled) 0 (disabled) The meaning of the security bits SEC[1:0] is shown in Table 7-4. For security reasons, the state of device security is controlled by two bits. To put the device in unsecured mode, these bits must be programmed to S12XS-Family Reference Manual, Rev. 1.03 224 PRELIMINARY Freescale Semiconductor Security (S12XS9SECV2) SEC[1:0] = ‘10’. All other combinations put the device in a secured mode. The recommended value to put the device in secured state is the inverse of the unsecured state, i.e. SEC[1:0] = ‘01’. Table 7-4. Security Bits SEC[1:0] 00 01 10 11 Security State 1 (secured) 1 (secured) 0 (unsecured) 1 (secured) NOTE Please refer to the Flash block guide for actual security configuration (in section “Flash Module Security”). 7.1.4 Operation of the Secured Microcontroller By securing the device, unauthorized access to the EEPROM and Flash memory contents can be prevented. However, it must be understood that the security of the EEPROM and Flash memory contents also depends on the design of the application program. For example, if the application has the capability of downloading code through a serial port and then executing that code (e.g. an application containing bootloader code), then this capability could potentially be used to read the EEPROM and Flash memory contents even when the microcontroller is in the secure state. In this example, the security of the application could be enhanced by requiring a challenge/response authentication before any code can be downloaded. Secured operation has the following effects on the microcontroller: S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 225 Security (S12XS9SECV2) 7.1.4.1 Normal Single Chip Mode (NS) • Background debug module (BDM) operation is completely disabled. • Execution of Flash and EEPROM commands is restricted. Please refer to the NVM block guide for details. • Tracing code execution using the DBG module is disabled. 7.1.4.2 Special Single Chip Mode (SS) • BDM firmware commands are disabled. • BDM hardware commands are restricted to the register space. • Execution of Flash and EEPROM commands is restricted. Please refer to the NVM block guide for details. • Tracing code execution using the DBG module is disabled. Special single chip mode means BDM is active after reset. The availability of BDM firmware commands depends on the security state of the device. The BDM secure firmware first performs a blank check of both the Flash memory and the EEPROM. If the blank check succeeds, security will be temporarily turned off and the state of the security bits in the appropriate Flash memory location can be changed If the blank check fails, security will remain active, only the BDM hardware commands will be enabled, and the accessible memory space is restricted to the peripheral register area. This will allow the BDM to be used to erase the EEPROM and Flash memory without giving access to their contents. After erasing both Flash memory and EEPROM, another reset into special single chip mode will cause the blank check to succeed and the options/security byte can be programmed to “unsecured” state via BDM. While the BDM is executing the blank check, the BDM interface is completely blocked, which means that all BDM commands are temporarily blocked. S12XS-Family Reference Manual, Rev. 1.03 226 PRELIMINARY Freescale Semiconductor 7.1.5 Unsecuring the Microcontroller Unsecuring the microcontroller can be done by three different methods: 1. Backdoor key access 2. Reprogramming the security bits 3. Complete memory erase (special modes) Security (S12XS9SECV2) 7.1.5.1 Unsecuring the MCU Using the Backdoor Key Access In normal modes (single chip and expanded), security can be temporarily disabled using the backdoor key access method. This method requires that: • The backdoor key at 0xFF00–0xFF07 (= global addresses 0x7F_FF00–0x7F_FF07) has been programmed to a valid value. • The KEYEN[1:0] bits within the Flash options/security byte select ‘enabled’. • In single chip mode, the application program programmed into the microcontroller must be designed to have the capability to write to the backdoor key locations. The backdoor key values themselves would not normally be stored within the application data, which means the application program would have to be designed to receive the backdoor key values from an external source (e.g. through a serial port). The backdoor key access method allows debugging of a secured microcontroller without having to erase the Flash. This is particularly useful for failure analysis. NOTE No word of the backdoor key is allowed to have the value 0x0000 or 0xFFFF. 7.1.6 Reprogramming the Security Bits In normal single chip mode (NS), security can also be disabled by erasing and reprogramming the security bits within Flash options/security byte to the unsecured value. Because the erase operation will erase the entire sector from 0xFE00–0xFFFF (0x7F_FE00–0x7F_FFFF), the backdoor key and the interrupt vectors will also be erased; this method is not recommended for normal single chip mode. The application software can only erase and program the Flash options/security byte if the Flash sector containing the Flash options/security byte is not protected (see Flash protection). Thus Flash protection is a useful means of preventing this method. The microcontroller will enter the unsecured state after the next reset following the programming of the security bits to the unsecured value. This method requires that: • The application software previously programmed into the microcontroller has been designed to have the capability to erase and program the Flash options/security byte, or security is first disabled using the backdoor key method, allowing BDM to be used to issue commands to erase and program the Flash options/security byte. • The Flash sector containing the Flash options/security byte is not protected. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 227 Security (S12XS9SECV2) 7.1.7 Complete Memory Erase (Special Modes) The microcontroller can be unsecured in special modes by erasing the entire EEPROM and Flash memory contents. When a secure microcontroller is reset into special single chip mode (SS), the BDM firmware verifies whether the EEPROM and Flash memory are erased. If any EEPROM or Flash memory address is not erased, only BDM hardware commands are enabled. BDM hardware commands can then be used to write to the EEPROM and Flash registers to mass erase the EEPROM and all Flash memory blocks. When next reset into special single chip mode, the BDM firmware will again verify whether all EEPROM and Flash memory are erased, and this being the case, will enable all BDM commands, allowing the Flash options/security byte to be programmed to the unsecured value. The security bits SEC[1:0] in the Flash security register will indicate the unsecure state following the next reset. S12XS-Family Reference Manual, Rev. 1.03 228 PRELIMINARY Freescale Semiconductor Chapter 8 S12XE Clocks and Reset Generator (S12XECRGV1) Revision History Version Revision Effective Number Date Date V01.00 26 Oct. 05 26 Oct. 05 V01.01 2 Nov. 06 2 Nov. 06 V01.02 4 Mar. 08 4 Mar. 08 Author Description of Changes Initial release Table “Examples of IPLL Divider settings”: corrected $32 to $31 correct details in Section 1.4.1.4 and Section 1.4.3.3 8.1 Introduction This specification describes the function of the Clocks and Reset Generator (S12XECRG). 8.1.1 Features The main features of this block are: • Phase Locked Loop (IPLL) frequency multiplier with internal filter — Reference divider — Post divider — Configurable internal filter (no external pin) — Optional frequency modulation for defined jitter and reduced emission — Automatic frequency lock detector — Interrupt request on entry or exit from locked condition — Self Clock Mode in absence of reference clock • System Clock Generator — Clock Quality Check — User selectable fast wake-up from Stop in Self-Clock Mode for power saving and immediate program execution — Clock switch for either Oscillator or PLL based system clocks • Computer Operating Properly (COP) watchdog timer with time-out clear window. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 229 S12XE Clocks and Reset Generator (S12XECRGV1) • System Reset generation from the following possible sources: — Power on reset — Low voltage reset — Illegal address reset — COP reset — Loss of clock reset — External pin reset • Real-Time Interrupt (RTI) S12XS-Family Reference Manual, Rev. 1.03 230 PRELIMINARY Freescale Semiconductor S12XE Clocks and Reset Generator (S12XECRGV1) 8.1.2 Modes of Operation This subsection lists and briefly describes all operating modes supported by the S12XECRG. • Run Mode All functional parts of the S12XECRG are running during normal Run Mode. If RTI or COP functionality is required the individual bits of the associated rate select registers (COPCTL, RTICTL) have to be set to a non zero value. • Wait Mode In this mode the IPLL can be disabled automatically depending on the PLLWAI bit. • Stop Mode Depending on the setting of the PSTP bit Stop Mode can be differentiated between Full Stop Mode (PSTP = 0) and Pseudo Stop Mode (PSTP = 1). — Full Stop Mode The oscillator is disabled and thus all system and core clocks are stopped. The COP and the RTI remain frozen. — Pseudo Stop Mode The oscillator continues to run and most of the system and core clocks are stopped. If the respective enable bits are set the COP and RTI will continue to run, else they remain frozen. • Self Clock Mode Self Clock Mode will be entered if the Clock Monitor Enable Bit (CME) and the Self Clock Mode Enable Bit (SCME) are both asserted and the clock monitor in the oscillator block detects a loss of clock. As soon as Self Clock Mode is entered the S12XECRG starts to perform a clock quality check. Self Clock Mode remains active until the clock quality check indicates that the required quality of the incoming clock signal is met (frequency and amplitude). Self Clock Mode should be used for safety purposes only. It provides reduced functionality to the MCU in case a loss of clock is causing severe system conditions. 8.1.3 Block Diagram Figure 8-1 shows a block diagram of the S12XECRG. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 231 S12XE Clocks and Reset Generator (S12XECRGV1) S12X_MMC Voltage Regulator Illegal Address Reset Power on Reset Low Voltage Reset RESET XCLKS Clock Monitor EXTAL XTAL Oscillator ICRG CM Fail OSCCLK COP Timeout Reset Generator Clock Quality Checker COP RTI VDDPLL VSSPLL PLLCLK IPLL Registers Clock and Reset Control Figure 8-1. Block diagram of S12XECRG 8.2 Signal Description This section lists and describes the signals that connect off chip. System Reset Bus Clock Core Clock Oscillator Clock Real Time Interrupt PLL Lock Interrupt Self Clock Mode Interrupt 8.2.1 VDDPLL, VSSPLL These pins provides operating voltage (VDDPLL) and ground (VSSPLL) for the IPLL circuitry. This allows the supply voltage to the IPLL to be independently bypassed. Even if IPLL usage is not required VDDPLL and VSSPLL must be connected to properly. 8.2.2 RESET RESET is an active low bidirectional reset pin. As an input it initializes the MCU asynchronously to a known start-up state. As an open-drain output it indicates that an system reset (internal to MCU) has been triggered. S12XS-Family Reference Manual, Rev. 1.03 232 PRELIMINARY Freescale Semiconductor S12XE Clocks and Reset Generator (S12XECRGV1) 8.3 Memory Map and Registers This section provides a detailed description of all registers accessible in the S12XECRG. 8.3.1 Module Memory Map Figure 8-2 gives an overview on all S12XECRG registers. Address Name Bit 7 6 5 4 0x0000 R SYNR W VCOFRQ[1:0] R 0x0001 REFDV W REFFRQ[1:0] R 0 0 0 0x0002 POSTDIV W R 0x0003 CRGFLG W RTIF PORF LVRF LOCKIF R 0 0x0004 CRGINT RTIE W 0 LOCKIE R XCLKS 0 0x0005 CLKSEL PLLSEL PSTP W R 0x0006 PLLCTL W CME PLLON FM1 FM0 R 0x0007 RTICTL RTDEC W RTR6 RTR5 RTR4 R 0 0 0x0008 COPCTL WCOP RSBCK W WRTMASK 0x0009 FORBYP2 R 0 0 0 0 W 0x000A CTCTL2 R 0 0 0 0 W R 0x000B ARMCOP W 0 Bit 7 0 Bit 6 0 Bit 5 0 Bit 4 2. FORBYP and CTCTL are intended for factory test purposes only. = Unimplemented or Reserved 3 2 1 SYNDIV[5:0] REFDIV[5:0] POSTDIV[4:0] LOCK ILAF SCMIF 0 0 SCMIE 0 PLLWAI RTIWAI FSTWKP PRE PCE RTR3 0 0 RTR2 CR2 0 RTR1 CR1 0 0 0 0 0 Bit 3 0 Bit 2 0 Bit 1 Figure 8-2. CRG Register Summary Bit 0 SCM 0 COPWAI SCME RTR0 CR0 0 0 0 Bit 0 NOTE Register Address = Base Address + Address Offset, where the Base Address is defined at the MCU level and the Address Offset is defined at the module level. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 233 S12XE Clocks and Reset Generator (S12XECRGV1) 8.3.2 Register Descriptions This section describes in address order all the S12XECRG registers and their individual bits. 8.3.2.1 S12XECRG Synthesizer Register (SYNR) The SYNR register controls the multiplication factor of the IPLL and selects the VCO frequency range. Module Base + 0x0000 7 6 5 4 3 2 1 0 R VCOFRQ[1:0] W SYNDIV[5:0] Reset 0 0 0 0 0 0 0 0 Figure 8-3. S12XECRG Synthesizer Register (SYNR) Read: Anytime Write: Anytime except if PLLSEL = 1 NOTE Write to this register initializes the lock detector bit. 频率公式 f VCO = 2 × f OSC × -((--SR---Y-E---N-F----DD----I-I--VV------++----1-1---))- f PLL = 2-----×-----P-f--VO-----CS---T-O----D----I---V-- f BUS = f---P---2-L---L-- NOTE fVCO must be within the specified VCO frequency lock range. F.BUS (Bus Clock) must not exceed the specified maximum. If POSTDIV = $00 then fPLL is same as fVCO (divide by one). The VCOFRQ[1:0] bit are used to configure the VCO gain for optimal stability and lock time. For correct IPLL operation the VCOFRQ[1:0] bits have to be selected according to the actual target VCOCLK frequency as shown in Table 8-1. Setting the VCOFRQ[1:0] bits wrong can result in a non functional IPLL (no locking and/or insufficient stability). Table 8-1. VCO Clock Frequency Selection VCOCLK Frequency Ranges 32MHz <= fVCO<= 48MHz 48MHz < fVCO<= 80MHz Reserved 80MHz < fVCO <= 120MHz VCOFRQ[1:0] 00 01 10 11 S12XS-Family Reference Manual, Rev. 1.03 234 PRELIMINARY Freescale Semiconductor S12XE Clocks and Reset Generator (S12XECRGV1) 8.3.2.2 S12XECRG Reference Divider Register (REFDV) The REFDV register provides a finer granularity for the IPLL multiplier steps. Module Base + 0x0001 7 6 5 4 3 2 1 0 R REFFRQ[1:0] W REFDIV[5:0] Reset 0 0 0 0 0 0 0 0 Figure 8-4. S12XECRG Reference Divider Register (REFDV) Read: Anytime Write: Anytime except when PLLSEL = 1 NOTE Write to this register initializes the lock detector bit. f REF = (---R----E----F-f--OD-----SI--V-C-----+-----1----) The REFFRQ[1:0] bit are used to configure the internal PLL filter for optimal stability and lock time. For correct IPLL operation the REFFRQ[1:0] bits have to be selected according to the actual REFCLK frequency as shown in Figure 8-2. Setting the REFFRQ[1:0] bits wrong can result in a non functional IPLL (no locking and/or insufficient stability). Table 8-2. Reference Clock Frequency Selection REFCLK Frequency Ranges 1MHz <= fREF <= 2MHz 2MHz < fREF <= 6MHz 6MHz < fREF <= 12MHz fREF >12MHz REFFRQ[1:0] 00 01 10 11 S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 235 S12XE Clocks and Reset Generator (S12XECRGV1) 8.3.2.3 S12XECRG Post Divider Register (POSTDIV) The POSTDIV register controls the frequency ratio between the VCOCLK and PLLCLK. The count in the final divider divides VCOCLK frequency by 1 or 2*POSTDIV. Note that if POSTDIV = $00 fPLL= fVCO (divide by one). Module Base + 0x0002 7 6 5 4 3 2 1 0 R 0 0 0 W POSTDIV[4:0] Reset 0 0 0 0 0 0 0 0 = Unimplemented or Reserved Figure 8-5. S12XECRG Post Divider Register (POSTDIV) Read: Anytime Write: Anytime except if PLLSEL = 1 f PLL = (---2---x---P---f-O-V----S-C--T--O--D-----I--V-----) NOTE If POSTDIV = $00 then fPLL is identical to fVCO (divide by one). 8.3.2.4 S12XECRG Flags Register (CRGFLG) This register provides S12XECRG status bits and flags. Module Base + 0x0002 7 R RTIF W 6 PORF 5 LVRF 4 LOCKIF 3 LOCK 2 ILAF 1 SCMIF 0 SCM Reset 0 Note 1 Note 2 Note 3 0 0 0 0 1. PORF is set to 1 when a power on reset occurs. Unaffected by system reset. 2. LVRF is set to 1 when a low voltage reset occurs. Unaffected by system reset. 3. ILAF is set to 1 when an illegal address reset occurs. Unaffected by system reset. Cleared by power on or low voltage reset. = Unimplemented or Reserved Figure 8-6. S12XECRG Flags Register (CRGFLG) Read: Anytime Write: Refer to each bit for individual write conditions S12XS-Family Reference Manual, Rev. 1.03 236 PRELIMINARY Freescale Semiconductor S12XE Clocks and Reset Generator (S12XECRGV1) Table 8-3. CRGFLG Field Descriptions Field 7 RTIF 6 PORF 5 LVRF 4 LOCKIF 3 LOCK 2 ILAF 1 SCMIF 0 SCM Description Real Time Interrupt Flag — RTIF is set to 1 at the end of the RTI period. This flag can only be cleared by writing a 1. Writing a 0 has no effect. If enabled (RTIE=1), RTIF causes an interrupt request. 0 RTI time-out has not yet occurred. 1 RTI time-out has occurred. Power on Reset Flag — PORF is set to 1 when a power on reset occurs. This flag can only be cleared by writing a 1. Writing a 0 has no effect. 0 Power on reset has not occurred. 1 Power on reset has occurred. Low Voltage Reset Flag — LVRF is set to 1 when a low voltage reset occurs. This flag can only be cleared by writing a 1. Writing a 0 has no effect. 0 Low voltage reset has not occurred. 1 Low voltage reset has occurred. IPLL Lock Interrupt Flag — LOCKIF is set to 1 when LOCK status bit changes. This flag can only be cleared by writing a 1. Writing a 0 has no effect.If enabled (LOCKIE=1), LOCKIF causes an interrupt request. 0 No change in LOCK bit. 1 LOCK bit has changed. Lock Status Bit — LOCK reflects the current state of IPLL lock condition. This bit is cleared in Self Clock Mode. Writes have no effect. 0 VCOCLK is not within the desired tolerance of the target frequency. 1 VCOCLK is within the desired tolerance of the target frequency. Illegal Address Reset Flag — ILAF is set to 1 when an illegal address reset occurs. Refer to S12XMMC Block Guide for details. This flag can only be cleared by writing a 1. Writing a 0 has no effect. 0 Illegal address reset has not occurred. 1 Illegal address reset has occurred. Self Clock Mode Interrupt Flag — SCMIF is set to 1 when SCM status bit changes. This flag can only be cleared by writing a 1. Writing a 0 has no effect. If enabled (SCMIE=1), SCMIF causes an interrupt request. 0 No change in SCM bit. 1 SCM bit has changed. Self Clock Mode Status Bit — SCM reflects the current clocking mode. Writes have no effect. 0 MCU is operating normally with OSCCLK available. 1 MCU is operating in Self Clock Mode with OSCCLK in an unknown state. All clocks are derived from PLLCLK running at its minimum frequency fSCM. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 237 S12XE Clocks and Reset Generator (S12XECRGV1) 8.3.2.5 S12XECRG Interrupt Enable Register (CRGINT) This register enables S12XECRG interrupt requests. Module Base + 0x0004 7 6 R 0 RTIE W 5 4 3 0 0 LOCKIE 2 1 0 0 0 SCMIE Reset 0 0 0 0 0 0 0 0 = Unimplemented or Reserved Figure 8-7. S12XECRG Interrupt Enable Register (CRGINT) Read: Anytime Write: Anytime Table 8-4. CRGINT Field Descriptions Field 7 RTIE 4 LOCKIE 1 SCMIE Description Real Time Interrupt Enable Bit 0 Interrupt requests from RTI are disabled. 1 Interrupt will be requested whenever RTIF is set. Lock Interrupt Enable Bit 0 LOCK interrupt requests are disabled. 1 Interrupt will be requested whenever LOCKIF is set. Self Clock Mode Interrupt Enable Bit 0 SCM interrupt requests are disabled. 1 Interrupt will be requested whenever SCMIF is set. S12XS-Family Reference Manual, Rev. 1.03 238 PRELIMINARY Freescale Semiconductor S12XE Clocks and Reset Generator (S12XECRGV1) 8.3.2.6 S12XECRG Clock Select Register (CLKSEL) This register controls S12XECRG clock selection. Refer toFigure 8-16 for more details on the effect of each bit. Module Base + 0x0005 R W Reset 7 PLLSEL 0 6 5 4 3 2 XCLKS 0 0 PSTP PLLWAI 0 0 0 0 0 = Unimplemented or Reserved Figure 8-8. S12XECRG Clock Select Register (CLKSEL) 1 RTIWAI 0 0 COPWAI 0 Read: Anytime Write: Refer to each bit for individual write conditions Table 8-5. CLKSEL Field Descriptions Field 7 PLLSEL 6 PSTP 5 XCLKS 3 PLLWAI Description PLL Select Bit Write: Anytime. Writing a one when LOCK=0 has no effect. This prevents the selection of an unstable PLLCLK as SYSCLK. PLLSEL bit is cleared when the MCU enters Self Clock Mode, Stop Mode or Wait Mode with PLLWAI bit set. It is recommended to read back the PLLSEL bit to make sure PLLCLK has really been selected as SYSCLK, as LOCK status bit could theoretically change at the very moment writing the PLLSEL bit. 0 System clocks are derived from OSCCLK (fBUS = fOSC / 2). 1 System clocks are derived from PLLCLK (fBUS = fPLL / 2). Pseudo Stop Bit Write: Anytime This bit controls the functionality of the oscillator during Stop Mode. 0 Oscillator is disabled in Stop Mode. 1 Oscillator continues to run in Stop Mode (Pseudo Stop). Note: Pseudo Stop Mode allows for faster STOP recovery and reduces the mechanical stress and aging of the resonator in case of frequent STOP conditions at the expense of a slightly increased power consumption. Oscillator Configuration Status Bit — This read-only bit shows the oscillator configuration status. 0 Loop controlled Pierce Oscillator is selected. 1 External clock / full swing Pierce Oscillator is selected. PLL Stops in Wait Mode Bit Write: Anytime If PLLWAI is set, the S12XECRG will clear the PLLSEL bit before entering Wait Mode. The PLLON bit remains set during Wait Mode but the IPLL is powered down. Upon exiting Wait Mode, the PLLSEL bit has to be set manually if PLL clock is required. 0 IPLL keeps running in Wait Mode. 1 IPLL stops in Wait Mode. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 239 S12XE Clocks and Reset Generator (S12XECRGV1) Table 8-5. CLKSEL Field Descriptions (continued) Field 1 RTIWAI 0 COPWAI Description RTI Stops in Wait Mode Bit Write: Anytime 0 RTI keeps running in Wait Mode. 1 RTI stops and initializes the RTI dividers whenever the part goes into Wait Mode. COP Stops in Wait Mode Bit Normal modes: Write once Special modes: Write anytime 0 COP keeps running in Wait Mode. 1 COP stops and initializes the COP counter whenever the part goes into Wait Mode. 8.3.2.7 S12XECRG IPLL Control Register (PLLCTL) This register controls the IPLL functionality. Module Base + 0x0006 R W Reset 7 CME 1 6 PLLON 1 5 FM1 0 4 FM0 0 3 FSTWKP 0 2 PRE 0 1 PCE 0 0 SCME 1 Figure 8-9. S12XECRG IPLL Control Register (PLLCTL) Read: Anytime Write: Refer to each bit for individual write conditions Table 8-6. PLLCTL Field Descriptions Field 7 CME 6 PLLON Description Clock Monitor Enable Bit — CME enables the clock monitor. Write anytime except when SCM = 1. 0 Clock monitor is disabled. 1 Clock monitor is enabled. Slow or stopped clocks will cause a clock monitor reset sequence or Self Clock Mode. Note: Operating with CME=0 will not detect any loss of clock. In case of poor clock quality this could cause unpredictable operation of the MCU! In Stop Mode (PSTP=0) the clock monitor is disabled independently of the CME bit setting and any loss of external clock will not be detected. Also after wake-up from stop mode (PSTP = 0) with fast wake-up enabled (FSTWKP = 1) the clock monitor is disabled independently of the CME bit setting and any loss of external clock will not be detected. Phase Lock Loop On Bit — PLLON turns on the IPLL circuitry. In Self Clock Mode, the IPLL is turned on, but the PLLON bit reads the last written value. Write anytime except when PLLSEL = 1. 0 IPLL is turned off. 1 IPLL is turned on. S12XS-Family Reference Manual, Rev. 1.03 240 PRELIMINARY Freescale Semiconductor S12XE Clocks and Reset Generator (S12XECRGV1) Table 8-6. PLLCTL Field Descriptions (continued) Field Description 5, 4 IPLL Frequency Modulation Enable Bit — FM1 and FM0 enable additional frequency modulation on the FM1, FM0 VCOCLK. This is to reduce noise emission. The modulation frequency is fref divided by 16. Write anytime except when PLLSEL = 1. See Table 8-7 for coding. 3 FSTWKP Fast Wake-up from Full Stop Bit — FSTWKP enables fast wake-up from full stop mode. Write anytime. If SelfClock Mode is disabled (SCME = 0) this bit has no effect. 0 Fast wake-up from full stop mode is disabled. 1 Fast wake-up from full stop mode is enabled. When waking up from full stop mode the system will immediately resume operation in Self-Clock Mode (see Section 8.4.1.4, “Clock Quality Checker”). The SCMIF flag will not be set. The system will remain in Self-Clock Mode with oscillator and clock monitor disabled until FSTWKP bit is cleared. The clearing of FSTWKP will start the oscillator, the clock monitor and the clock quality check. If the clock quality check is successful, the S12XECRG will switch all system clocks to OSCCLK. The SCMIF flag will be set. See application examples in Figure 8-19 and Figure 8-20. 2 PRE RTI Enable During Pseudo Stop Bit — PRE enables the RTI during Pseudo Stop Mode. Write anytime. 0 RTI stops running during Pseudo Stop Mode. 1 RTI continues running during Pseudo Stop Mode. Note: If the PRE bit is cleared the RTI dividers will go static while Pseudo Stop Mode is active. The RTI dividers will not initialize like in Wait Mode with RTIWAI bit set. 1 PCE COP Enable During Pseudo Stop Bit — PCE enables the COP during Pseudo Stop Mode. Write anytime. 0 COP stops running during Pseudo Stop Mode 1 COP continues running during Pseudo Stop Mode Note: If the PCE bit is cleared the COP dividers will go static while Pseudo Stop Mode is active. The COP dividers will not initialize like in Wait Mode with COPWAI bit set. 0 SCME Self Clock Mode Enable Bit Normal modes: Write once Special modes: Write anytime SCME can not be cleared while operating in Self Clock Mode (SCM = 1). 0 Detection of crystal clock failure causes clock monitor reset (see Section 8.5.1.1, “Clock Monitor Reset”). 1 Detection of crystal clock failure forces the MCU in Self Clock Mode (see Section 8.4.2.2, “Self Clock Mode”). Table 8-7. FM Amplitude selection FM1 0 0 1 1 FM0 0 1 0 1 FM Amplitude / fVCO Variation FM off ±1% ±2% ±4% S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 241 S12XE Clocks and Reset Generator (S12XECRGV1) 8.3.2.8 S12XECRG RTI Control Register (RTICTL) This register selects the timeout period for the Real Time Interrupt. Module Base + 0x0007 R W Reset 7 RTDEC 0 6 RTR6 5 RTR5 4 RTR4 3 RTR3 2 RTR2 0 0 0 0 0 Figure 8-10. S12XECRG RTI Control Register (RTICTL) Read: Anytime Write: Anytime NOTE A write to this register initializes the RTI counter. Table 8-8. RTICTL Field Descriptions 1 RTR1 0 0 RTR0 0 Field 7 RTDEC 6–4 RTR[6:4] 3–0 RTR[3:0] Description Decimal or Binary Divider Select Bit — RTDEC selects decimal or binary based prescaler values. 0 Binary based divider value. See Table 8-9 1 Decimal based divider value. See Table 8-10 Real Time Interrupt Prescale Rate Select Bits — These bits select the prescale rate for the RTI. See Table 89 and Table 8-10. Real Time Interrupt Modulus Counter Select Bits — These bits select the modulus counter target value to provide additional granularity.Table 8-9 and Table 8-10 show all possible divide values selectable by the RTICTL register. The source clock for the RTI is OSCCLK. RTR[3:0] 0000 (÷1) 0001 (÷2) 0010 (÷3) 0011 (÷4) 0100 (÷5) 0101 (÷6) 0110 (÷7) Table 8-9. RTI Frequency Divide Rates for RTDEC = 0 RTR[6:4] = 000 (OFF) OFF1 OFF OFF OFF OFF OFF OFF 001 (210) 210 2x210 3x210 4x210 5x210 6x210 7x210 010 (211) 211 2x211 3x211 4x211 5x211 6x211 7x211 011 (212) 212 2x212 3x212 4x212 5x212 6x212 7x212 100 (213) 213 2x213 3x213 4x213 5x213 6x213 7x213 101 (214) 214 2x214 3x214 4x214 5x214 6x214 7x214 110 (215) 215 2x215 3x215 4x215 5x215 6x215 7x215 111 (216) 216 2x216 3x216 4x216 5x216 6x216 7x216 S12XS-Family Reference Manual, Rev. 1.03 242 PRELIMINARY Freescale Semiconductor S12XE Clocks and Reset Generator (S12XECRGV1) Table 8-9. RTI Frequency Divide Rates for RTDEC = 0 RTR[6:4] = RTR[3:0] 000 (OFF) 001 (210) 010 (211) 011 (212) 100 (213) 101 (214) 110 (215) 111 (216) 0111 (÷8) OFF 8x210 8x211 8x212 8x213 8x214 8x215 8x216 1000 (÷9) OFF 9x210 9x211 9x212 9x213 9x214 9x215 9x216 1001 (÷10) OFF 10x210 10x211 10x212 10x213 10x214 10x215 10x216 1010 (÷11) OFF 11x210 11x211 11x212 11x213 11x214 11x215 11x216 1011 (÷12) OFF 12x210 12x211 12x212 12x213 12x214 12x215 12x216 1100 (÷13) OFF 13x210 13x211 13x212 13x213 13x214 13x215 13x216 1101 (÷14) OFF 14x210 14x211 14x212 14x213 14x214 14x215 14x216 1110 (÷15) OFF 15x210 15x211 15x212 15x213 15x214 15x215 15x216 1111 (÷16) OFF 16x210 16x211 16x212 16x213 16x214 16x215 16x216 1 Denotes the default value out of reset.This value should be used to disable the RTI to ensure future backwards compatibility. RTR[3:0] 0000 (÷1) 0001 (÷2) 0010 (÷3) 0011 (÷4) 0100 (÷5) 0101 (÷6) 0110 (÷7) 0111 (÷8) 1000 (÷9) 1001 (÷10) 1010 (÷11) 1011 (÷12) Table 8-10. RTI Frequency Divide Rates for RTDEC=1 000 (1x103) 1x103 2x103 3x103 4x103 5x103 6x103 7x103 8x103 9x103 10 x103 11 x103 12x103 001 (2x103) 2x103 4x103 6x103 8x103 10x103 12x103 14x103 16x103 18x103 20x103 22x103 24x103 010 (5x103) 5x103 10x103 15x103 20x103 25x103 30x103 35x103 40x103 45x103 50x103 55x103 60x103 RTR[6:4] = 011 (10x103) 10x103 20x103 30x103 40x103 50x103 60x103 70x103 80x103 90x103 100x103 110x103 120x103 100 (20x103) 20x103 40x103 60x103 80x103 100x103 120x103 140x103 160x103 180x103 200x103 220x103 240x103 101 (50x103) 50x103 100x103 150x103 200x103 250x103 300x103 350x103 400x103 450x103 500x103 550x103 600x103 110 (100x103) 100x103 200x103 300x103 400x103 500x103 600x103 700x103 800x103 900x103 1x106 1.1x106 1.2x106 111 (200x103) 200x103 400x103 600x103 800x103 1x106 1.2x106 1.4x106 1.6x106 1.8x106 2x106 2.2x106 2.4x106 S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 243 S12XE Clocks and Reset Generator (S12XECRGV1) Table 8-10. RTI Frequency Divide Rates for RTDEC=1 RTR[3:0] 1100 (÷13) 1101 (÷14) 1110 (÷15) 1111 (÷16) 000 (1x103) 13x103 14x103 15x103 16x103 001 (2x103) 26x103 28x103 30x103 32x103 010 (5x103) 65x103 70x103 75x103 80x103 RTR[6:4] = 011 (10x103) 130x103 140x103 150x103 160x103 100 (20x103) 260x103 280x103 300x103 320x103 101 (50x103) 650x103 700x103 750x103 800x103 110 (100x103) 1.3x106 1.4x106 1.5x106 1.6x106 111 (200x103) 2.6x106 2.8x106 3x106 3.2x106 S12XS-Family Reference Manual, Rev. 1.03 244 PRELIMINARY Freescale Semiconductor S12XE Clocks and Reset Generator (S12XECRGV1) 8.3.2.9 S12XECRG COP Control Register (COPCTL) This register controls the COP (Computer Operating Properly) watchdog. Module Base + 0x0008 7 6 5 4 R 0 0 WCOP RSBCK W WRTMASK Reset1 0 0 0 0 3 2 1 0 0 CR2 CR1 CR0 0 0 0 0 1. Refer to Device User Guide (Section: S12XECRG) for reset values of WCOP, CR2, CR1 and CR0. = Unimplemented or Reserved Figure 8-11. S12XECRG COP Control Register (COPCTL) Read: Anytime Write: 1. RSBCK: anytime in special modes; write to “1” but not to “0” in all other modes 2. WCOP, CR2, CR1, CR0: — Anytime in special modes — Write once in all other modes – Writing CR[2:0] to “000” has no effect, but counts for the “write once” condition. – Writing WCOP to “0” has no effect, but counts for the “write once” condition. The COP time-out period is restarted if one these two conditions is true: 1. Writing a non zero value to CR[2:0] (anytime in special modes, once in all other modes) with WRTMASK = 0. or 2. Changing RSBCK bit from “0” to “1”. Table 8-11. COPCTL Field Descriptions Field 7 WCOP 6 RSBCK Description Window COP Mode Bit — When set, a write to the ARMCOP register must occur in the last 25% of the selected period. A write during the first 75% of the selected period will reset the part. As long as all writes occur during this window, $55 can be written as often as desired. Once $AA is written after the $55, the time-out logic restarts and the user must wait until the next window before writing to ARMCOP. Table 8-12 shows the duration of this window for the seven available COP rates. 0 Normal COP operation 1 Window COP operation COP and RTI Stop in Active BDM Mode Bit 0 Allows the COP and RTI to keep running in Active BDM mode. 1 Stops the COP and RTI counters whenever the part is in Active BDM mode. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 245 S12XE Clocks and Reset Generator (S12XECRGV1) Table 8-11. COPCTL Field Descriptions (continued) Field Description 5 WRTMASK Write Mask for WCOP and CR[2:0] Bit — This write-only bit serves as a mask for the WCOP and CR[2:0] bits while writing the COPCTL register. It is intended for BDM writing the RSBCK without touching the contents of WCOP and CR[2:0]. 0 Write of WCOP and CR[2:0] has an effect with this write of COPCTL 1 Write of WCOP and CR[2:0] has no effect with this write of COPCTL. (Does not count for “write once”.) 2–0 CR[2:0] COP Watchdog Timer Rate Select — These bits select the COP time-out rate (see Table 8-12). Writing a nonzero value to CR[2:0] enables the COP counter and starts the time-out period. A COP counter time-out causes a system reset. This can be avoided by periodically (before time-out) reinitialize the COP counter via the ARMCOP register. While all of the following four conditions are true the CR[2:0], WCOP bits are ignored and the COP operates at highest time-out period (2 24 cycles) in normal COP mode (Window COP mode disabled): 1) COP is enabled (CR[2:0] is not 000) 2) BDM mode active 3) RSBCK = 0 4) Operation in emulation or special modes Table 8-12. COP Watchdog Rates1 CR2 CR1 CR0 OSCCLK Cycles to Timeout 0 0 0 COP disabled 0 0 1 2 14 0 1 0 2 16 0 1 1 2 18 1 0 0 2 20 1 0 1 2 22 1 1 0 2 23 1 1 1 2 24 1 OSCCLK cycles are referenced from the previous COP time-out reset (writing $55/$AA to the ARMCOP register) S12XS-Family Reference Manual, Rev. 1.03 246 PRELIMINARY Freescale Semiconductor S12XE Clocks and Reset Generator (S12XECRGV1) 8.3.2.10 Reserved Register (FORBYP) NOTE This reserved register is designed for factory test purposes only, and is not intended for general user access. Writing to this register when in special modes can alter the S12XECRG’s functionality. Module Base + 0x0009 7 6 5 4 3 2 1 0 R 0 0 0 0 0 0 0 0 W Reset 0 0 0 0 0 0 0 0 = Unimplemented or Reserved Figure 8-12. Reserved Register (FORBYP) Read: Always read $00 except in special modes Write: Only in special modes 8.3.2.11 Reserved Register (CTCTL) NOTE This reserved register is designed for factory test purposes only, and is not intended for general user access. Writing to this register when in special test modes can alter the S12XECRG’s functionality. Module Base + 0x000A 7 6 5 4 3 2 1 0 R 0 0 0 0 0 0 0 0 W Reset 0 0 0 0 0 0 0 0 = Unimplemented or Reserved Figure 8-13. Reserved Register (CTCTL) Read: Always read $00 except in special modes Write: Only in special modes S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 247 S12XE Clocks and Reset Generator (S12XECRGV1) 8.3.2.12 S12XECRG COP Timer Arm/Reset Register (ARMCOP) This register is used to restart the COP time-out period. Module Base + 0x000B 7 6 5 4 3 2 1 0 R 0 0 0 0 0 0 0 0 W Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset 0 0 0 0 0 0 0 0 Figure 8-14. S12XECRG ARMCOP Register Diagram Read: Always reads $00 Write: Anytime When the COP is disabled (CR[2:0] = “000”) writing to this register has no effect. When the COP is enabled by setting CR[2:0] nonzero, the following applies: Writing any value other than $55 or $AA causes a COP reset. To restart the COP time-out period you must write $55 followed by a write of $AA. Other instructions may be executed between these writes but the sequence ($55, $AA) must be completed prior to COP end of time-out period to avoid a COP reset. Sequences of $55 writes or sequences of $AA writes are allowed. When the WCOP bit is set, $55 and $AA writes must be done in the last 25% of the selected time-out period; writing any value in the first 75% of the selected period will cause a COP reset. S12XS-Family Reference Manual, Rev. 1.03 248 PRELIMINARY Freescale Semiconductor 8.4 Functional Description 8.4.1 Functional Blocks S12XE Clocks and Reset Generator (S12XECRGV1) 锁相环路与内部过滤器 8.4.1.1 Phase Locked Loop with Internal Filter (IPLL) The IPLL is used to run the MCU from a different time base than the incoming OSCCLK. Figure 8-15 shows a block diagram of the IPLL. EXTAL XTAL REDUCED CONSUMPTION OSCCLK OSCILLATOR REFDIV[5:0] REFCLK FBCLK LOCK DETECTOR LOCK REFERENCE PROGRAMMABLE DIVIDER PDET PHASE DETECTOR VDDPLL/VSSPLL UP CPUMP DOWN AND VCO FILTER CLOCK MONITOR Supplied by: VDDPLL/VSSPLL VDD/VSS LOOP PROGRAMMABLE DIVIDER SYNDIV[5:0] VCOCLK POST PROGRAMMABLE DIVIDER POSTDIV[4:0] PLLCLK Figure 8-15. IPLL Functional Diagram For increased flexibility, OSCCLK can be divided in a range of 1 to 64 to generate the reference frequency REFCLK using the REFDIV[5:0] bits. This offers a finer multiplication granularity. Based on the SYNDIV[5:0] bits the IPLL generates the VCOCLK by multiplying the reference clock by a multiple of 2, 4, 6,... 126, 128. Based on the POSTDIV[4:0] bits the VCOCLK can be divided in a range of 1,2,4,6,8,... to 62 to generate the PLLCLK. . f PLL = 2 × f OSC × [---R----E----F---D-----I--V--S----Y+----N-1---]-D--[--2I---V--×---+-P----O1-----S---T----D-----I--V-----] NOTE Although it is possible to set the dividers to command a very high clock frequency, do not exceed the specified bus frequency limit for the MCU. If (PLLSEL = 1) then fBUS = fPLL / 2. IF POSTDIV = $00 the fPLL is identical to fVCO (divide by one) S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 249 S12XE Clocks and Reset Generator (S12XECRGV1) Several examples of IPLL divider settings are shown in Table 8-13. Shaded rows indicated that these settings are not recommended. The following rules help to achieve optimum stability and shortest lock time: • Use lowest possible fVCO / fREF ratio (SYNDIV value). • Use highest possible REFCLK frequency fREF. Table 8-13. Examples of IPLL Divider Settings fOSC REFDIV[5:0] fREF REFFRQ[1:0] SYNDIV[5:0] fVCO VCOFRQ[1:0] POSTDIV[4:0] fPLL fBUS 4MHz $00 4MHz 01 $09 80MHz 01 $00 80MHz 40MHz 8MHz $00 8MHz 10 $04 80MHz 01 $00 80MHz 40MHz 4MHz $00 4MHz 01 $03 32MHz 00 $01 16MHz 8MHz 4MHz $01 2MHz 00 $18 100MHz 11 $01 50MHz 25MHz 4MHz $03 1MHz 00 $18 50MHz 01 $00 50MHz 25MHz 4MHz $03 1MHz 00 $31 100MHz 11 $01 50MHz 25MHz 8.4.1.1.1 IPLL Operation The oscillator output clock signal (OSCCLK) is fed through the reference programmable divider and is divided in a range of 1 to 64 (REFDIV+1) to output the REFCLK. The VCO output clock, (VCOCLK) is fed back through the programmable loop divider and is divided in a range of 2 to 128 in increments of [2 x (SYNDIV +1)] to output the FBCLK. The VCOCLK is fed to the final programmable divider and is divided in a range of 1,2,4,6,8,... to 62 (2*POSTDIV) to output the PLLCLK. See Figure 8-15. The phase detector then compares the FBCLK, with the REFCLK. Correction pulses are generated based on the phase difference between the two signals. The loop filter then slightly alters the DC voltage on the internal filter capacitor, based on the width and direction of the correction pulse. The user must select the range of the REFCLK frequency and the range of the VCOCLK frequency to ensure that the correct IPLL loop bandwidth is set. The lock detector compares the frequencies of the FBCLK, and the REFCLK. Therefore, the speed of the lock detector is directly proportional to the reference clock frequency. The circuit determines the lock condition based on this comparison. If IPLL LOCK interrupt requests are enabled, the software can wait for an interrupt request and then check the LOCK bit. If interrupt requests are disabled, software can poll the LOCK bit continuously (during IPLL start-up, usually) or at periodic intervals. In either case, only when the LOCK bit is set, the PLLCLK can be selected as the source for the system and core clocks. If the IPLL is selected as the source for the system and core clocks and the LOCK bit is clear, the IPLL has suffered a severe noise hit and the software must take appropriate action, depending on the application. • The LOCK bit is a read-only indicator of the locked state of the IPLL. • The LOCK bit is set when the VCO frequency is within a certain tolerance, ∆Lock, and is cleared when the VCO frequency is out of a certain tolerance, ∆unl. • Interrupt requests can occur if enabled (LOCKIE = 1) when the lock condition changes, toggling the LOCK bit. S12XS-Family Reference Manual, Rev. 1.03 250 PRELIMINARY Freescale Semiconductor 8.4.1.2 System Clocks Generator S12XE Clocks and Reset Generator (S12XECRGV1) 系统时钟寄存器 PLLSEL or SCM PHASE PLLCLK 1 LOCK LOOP (IIPLL) 0 STOP SYSCLK Core Clock EXTAL OSCCLK OSCILLATOR XTAL Clock Monitor SCM 1 0 WAIT(RTIWAI), STOP(PSTP, PRE), RTI ENABLE WAIT(COPWAI), STOP(PSTP, PCE), COP ENABLE ÷2 CLOCK PHASE GENERATOR RTI COP Bus Clock Gating Condition = Clock Gate STOP Oscillator Clock Figure 8-16. System Clocks Generator The clock generator creates the clocks used in the MCU (see Figure 8-16). The gating condition placed on top of the individual clock gates indicates the dependencies of different modes (STOP, WAIT) and the setting of the respective configuration bits. The peripheral modules use the Bus Clock. Some peripheral modules also use the Oscillator Clock. If the MCU enters Self Clock Mode (see Section 8.4.2.2, “Self Clock Mode”) Oscillator clock source is switched to PLLCLK running at its minimum frequency fSCM. The Bus Clock is used to generate the clock visible at the ECLK pin. The Core Clock signal is the clock for the CPU. The Core Clock is twice the Bus Clock. But note that a CPU cycle corresponds to one Bus Clock. IPLL clock mode is selected with PLLSEL bit in the CLKSEL register. When selected, the IPLL output clock drives SYSCLK for the main system including the CPU and peripherals. The IPLL cannot be turned off by clearing the PLLON bit, if the IPLL clock is selected. When PLLSEL is changed, it takes a maximum of 4 OSCCLK plus 4 PLLCLK cycles to make the transition. During the transition, all clocks freeze and CPU activity ceases. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 251 S12XE Clocks and Reset Generator (S12XECRGV1) 8.4.1.3 Clock Monitor (CM) If no OSCCLK edges are detected within a certain time, the clock monitor within the oscillator block generates a clock monitor fail event. The S12XECRG then asserts self clock mode or generates a system reset depending on the state of SCME bit. If the clock monitor is disabled or the presence of clocks is detected no failure is indicated by the oscillator block.The clock monitor function is enabled/disabled by the CME control bit. 8.4.1.4 Clock Quality Checker The clock monitor performs a coarse check on the incoming clock signal. The clock quality checker provides a more accurate check in addition to the clock monitor. A clock quality check is triggered by any of the following events: • Power on reset (POR) • Low voltage reset (LVR) • Wake-up from Full Stop Mode (exit full stop) • Clock Monitor fail indication (CM fail) A time window of 50000 PLLCLK cycles1 is called check window. A number greater equal than 4096 rising OSCCLK edges within a check window is called osc ok. Note that osc ok immediately terminates the current check window. See Figure 8-17 as an example. CHECK WINDOW PLLCLK 1 2 3 49999 50000 OSCCLK 12345 4096 4095 OSC OK Figure 8-17. Check Window Example 1. IPLL is running at self clock mode frequency fSCM. S12XS-Family Reference Manual, Rev. 1.03 252 PRELIMINARY Freescale Semiconductor S12XE Clocks and Reset Generator (S12XECRGV1) The Sequence for clock quality check is shown in Figure 8-18. CLOCK OK CM FAIL POR LVR EXIT FULL STOP SCME=1 & FSTWKP=1 ? NO YES NUM = 0 NO ENTER SCM CLOCK MONITOR RESET FSTWKP = 0 ? YES NUM = 50 CHECK WINDOW OSC OK NO ? YES SCM YES ACTIVE? NO ENTER SCM YES NUM = NUM-1 YES NO NUM > 0 ? NO SCM ACTIVE? NUM = 0 YES SCME = 1 NO ? SWITCH TO OSCCLK EXIT SCM Figure 8-18. Sequence for Clock Quality Check NOTE Remember that in parallel to additional actions caused by Self Clock Mode or Clock Monitor Reset1 handling the clock quality checker continues to check the OSCCLK signal. NOTE The Clock Quality Checker enables the IPLL and the voltage regulator (VREG) anytime a clock check has to be performed. An ongoing clock quality check could also cause a running IPLL (fSCM) and an active VREG during Pseudo Stop Mode. 1. A Clock Monitor Reset will always set the SCME bit to logical’1’. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 253 S12XE Clocks and Reset Generator (S12XECRGV1) 8.4.1.5 Computer Operating Properly Watchdog (COP) The COP (free running watchdog timer) enables the user to check that a program is running and sequencing properly. When the COP is being used, software is responsible for keeping the COP from timing out. If the COP times out it is an indication that the software is no longer being executed in the intended sequence; thus a system reset is initiated (see Section 8.4.1.5, “Computer Operating Properly Watchdog (COP)”). The COP runs with a gated OSCCLK. Three control bits in the COPCTL register allow selection of seven COP time-out periods. When COP is enabled, the program must write $55 and $AA (in this order) to the ARMCOP register during the selected time-out period. Once this is done, the COP time-out period is restarted. If the program fails to do this and the COP times out, the part will reset. Also, if any value other than $55 or $AA is written, the part is immediately reset. Windowed COP operation is enabled by setting WCOP in the COPCTL register. In this mode, writes to the ARMCOP register to clear the COP timer must occur in the last 25% of the selected time-out period. A premature write will immediately reset the part. If PCE bit is set, the COP will continue to run in Pseudo Stop Mode. 8.4.1.6 Real Time Interrupt (RTI) The RTI can be used to generate a hardware interrupt at a fixed periodic rate. If enabled (by setting RTIE=1), this interrupt will occur at the rate selected by the RTICTL register. The RTI runs with a gated OSCCLK. At the end of the RTI time-out period the RTIF flag is set to one and a new RTI time-out period starts immediately. A write to the RTICTL register restarts the RTI time-out period. If the PRE bit is set, the RTI will continue to run in Pseudo Stop Mode. 8.4.2 Operation Modes 8.4.2.1 Normal Mode The S12XECRG block behaves as described within this specification in all normal modes. 8.4.2.2 Self Clock Mode If the external clock frequency is not available due to a failure or due to long crystal start-up time, the Bus Clock and the Core Clock are derived from the PLLCLK running at self clock mode frequency fSCM; this mode of operation is called Self Clock Mode. This requires CME = 1 and SCME = 1, which is the default after reset. If the MCU was clocked by the PLLCLK prior to entering Self Clock Mode, the PLLSEL bit will be cleared. If the external clock signal has stabilized again, the S12XECRG will automatically select OSCCLK to be the system clock and return to normal mode. See Section 8.4.1.4, “Clock Quality Checker” for more information on entering and leaving Self Clock Mode. S12XS-Family Reference Manual, Rev. 1.03 254 PRELIMINARY Freescale Semiconductor S12XE Clocks and Reset Generator (S12XECRGV1) NOTE In order to detect a potential clock loss the CME bit should always be enabled (CME = 1). If CME bit is disabled and the MCU is configured to run on PLLCLK, a loss of external clock (OSCCLK) will not be detected and will cause the system clock to drift towards lower frequencies. As soon as the external clock is available again the system clock ramps up to its IPLL target frequency. If the MCU is running on external clock any loss of clock will cause the system to go static. 8.4.3 Low Power Options This section summarizes the low power options available in the S12XECRG. 8.4.3.1 Run Mode This is the default mode after reset. The RTI can be stopped by setting the associated rate select bits to zero. The COP can be stopped by setting the associated rate select bits to zero. 8.4.3.2 Wait Mode The WAI instruction puts the MCU in a low power consumption stand-by mode depending on setting of the individual bits in the CLKSEL register. All individual Wait Mode configuration bits can be superposed. This provides enhanced granularity in reducing the level of power consumption during Wait Mode. Table 8-14 lists the individual configuration bits and the parts of the MCU that are affected in Wait Mode. Table 8-14. MCU Configuration During Wait Mode IPLL RTI COP PLLWAI Stopped — — RTIWAI — Stopped — COPWAI — — Stopped After executing the WAI instruction the core requests the S12XECRG to switch MCU into Wait Mode. The S12XECRG then checks whether the PLLWAI bit is asserted. Depending on the configuration the S12XECRG switches the system and core clocks to OSCCLK by clearing the PLLSEL bit and disables the IPLL. There are two ways to restart the MCU from Wait Mode: 1. Any reset 2. Any interrupt S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 255 S12XE Clocks and Reset Generator (S12XECRGV1) 8.4.3.3 Stop Mode All clocks are stopped in STOP mode, dependent of the setting of the PCE, PRE and PSTP bit. The oscillator is disabled in STOP mode unless the PSTP bit is set. If the PRE or PCE bits are set, the RTI or COP continues to run in Pseudo Stop Mode. In addition to disabling system and core clocks the S12XECRG requests other functional units of the MCU (e.g. voltage-regulator) to enter their individual power saving modes (if available). If the PLLSEL bit is still set when entering Stop Mode, the S12XECRG will switch the system and core clocks to OSCCLK by clearing the PLLSEL bit. Then the S12XECRG disables the IPLL, disables the core clock and finally disables the remaining system clocks. If Pseudo Stop Mode is entered from Self-Clock Mode the S12XECRG will continue to check the clock quality until clock check is successful. In this case the IPLL and the voltage regulator (VREG) will remain enabled. If Full Stop Mode (PSTP = 0) is entered from Self-Clock Mode the ongoing clock quality check will be stopped. A complete timeout window check will be started when Stop Mode is left again. There are two ways to restart the MCU from Stop Mode: 1. Any reset 2. Any interrupt If the MCU is woken-up from Full Stop Mode by an interrupt and the fast wake-up feature is enabled (FSTWKP=1 and SCME=1), the system will immediately (no clock quality check) resume operation in Self-Clock Mode (see Section 8.4.1.4, “Clock Quality Checker”). The SCMIF flag will not be set for this special case. The system will remain in Self-Clock Mode with oscillator disabled until FSTWKP bit is cleared. The clearing of FSTWKP will start the oscillator and the clock quality check. If the clock quality check is successful, the S12XECRG will switch all system clocks to oscillator clock. The SCMIF flag will be set. See application examples in Figure 8-19 and Figure 8-20. Because the IPLL has been powered-down during Stop Mode the PLLSEL bit is cleared and the MCU runs on OSCCLK after leaving Stop-Mode. The software must manually set the PLLSEL bit again, in order to switch system and core clocks to the PLLCLK. NOTE In Full Stop Mode or Self-Clock Mode caused by the fast wake-up feature the clock monitor and the oscillator are disabled. S12XS-Family Reference Manual, Rev. 1.03 256 PRELIMINARY Freescale Semiconductor S12XE Clocks and Reset Generator (S12XECRGV1) Instruction FSTWKP=1 SCME=1 CPU resumes program execution immediately STOP IRQ service Interrupt STOP IRQ service Interrupt STOP IRQ service Interrupt Oscillator Clock Power Saving Oscillator Disabled PLL Clock Core Clock Self-Clock Mode Figure 8-19. Fast Wake-up from Full Stop Mode: Example 1 . CPU resumes program execution immediately Frequent Uncritical Frequent Critical Instructions Instructions Possible Instruction IRQ Service STOP FSTWKP=1 SCME=1 IRQ Interrupt FSTWKP=0 SCMIE=1 SCM Interrupt Oscillator Clock Clock Quality Check Oscillator Disabled Osc Startup PLL Clock Core Clock Self-Clock Mode Figure 8-20. Fast Wake-up from Full Stop Mode: Example 2 8.5 Resets All reset sources are listed in Table 8-15. Refer to MCU specification for related vector addresses and priorities. Table 8-15. Reset Summary Reset Source Power on Reset Low Voltage Reset External Reset Illegal Address Reset Clock Monitor Reset Local Enable None None None None PLLCTL (CME=1, SCME=0) S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 257 S12XE Clocks and Reset Generator (S12XECRGV1) Table 8-15. Reset Summary Reset Source COP Watchdog Reset Local Enable COPCTL (CR[2:0] nonzero) 8.5.1 Description of Reset Operation The reset sequence is initiated by any of the following events: • Low level is detected at the RESET pin (External Reset). • Power on is detected. • Low voltage is detected. • Illegal Address Reset is detected (see S12XMMC Block Guide for details). • COP watchdog times out. • Clock monitor failure is detected and Self-Clock Mode was disabled (SCME=0). Upon detection of any reset event, an internal circuit drives the RESET pin low for 128 SYSCLK cycles (see Figure 8-21). Since entry into reset is asynchronous it does not require a running SYSCLK. However, the internal reset circuit of the S12XECRG cannot sequence out of current reset condition without a running SYSCLK. The number of 128 SYSCLK cycles might be increased by n = 3 to 6 additional SYSCLK cycles depending on the internal synchronization latency. After 128+n SYSCLK cycles the RESET pin is released. The reset generator of the S12XECRG waits for additional 64 SYSCLK cycles and then samples the RESET pin to determine the originating source. Table 8-16 shows which vector will be fetched. Table 8-16. Reset Vector Selection Sampled RESET Pin Clock Monitor COP (64 cycles after release) Reset Pending Reset Pending Vector Fetch 1 0 0 POR / LVR / Illegal Address Reset/ External Reset 1 1 X Clock Monitor Reset 1 0 1 COP Reset 0 X X POR / LVR / Illegal Address Reset/ External Reset with rise of RESET pin NOTE External circuitry connected to the RESET pin should not include a large capacitance that would interfere with the ability of this signal to rise to a valid logic one within 64 SYSCLK cycles after the low drive is released. S12XS-Family Reference Manual, Rev. 1.03 258 PRELIMINARY Freescale Semiconductor S12XE Clocks and Reset Generator (S12XECRGV1) The internal reset of the MCU remains asserted while the reset generator completes the 192 SYSCLK long reset sequence. In case the RESET pin is externally driven low for more than these 192 SYSCLK cycles (External Reset), the internal reset remains asserted longer. Figure 8-21. RESET Timing RESET )( )( ICRG drives RESET pin low RESET pin released SYSCLK ) ) ) ( ( ( possibly SYSCLK not running 128+n cycles with n being min 3 / max 6 cycles depending on internal synchronization delay 64 cycles possibly RESET driven low externally 8.5.1.1 Clock Monitor Reset The S12XECRG generates a Clock Monitor Reset in case all of the following conditions are true: • Clock monitor is enabled (CME = 1) • Loss of clock is detected • Self-Clock Mode is disabled (SCME = 0). The reset event asynchronously forces the configuration registers to their default settings. In detail the CME and the SCME are reset to logical ‘1’ (which changes the state of the SCME bit. As a consequence the S12XECRG immediately enters Self Clock Mode and starts its internal reset sequence. In parallel the clock quality check starts. As soon as clock quality check indicates a valid Oscillator Clock the S12XECRG switches to OSCCLK and leaves Self Clock Mode. Since the clock quality checker is running in parallel to the reset generator, the S12XECRG may leave Self Clock Mode while still completing the internal reset sequence. 8.5.1.2 Computer Operating Properly Watchdog (COP) Reset When COP is enabled, the S12XECRG expects sequential write of $55 and $AA (in this order) to the ARMCOP register during the selected time-out period. Once this is done, the COP time-out period restarts. If the program fails to do this the S12XECRG will generate a reset. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 259 S12XE Clocks and Reset Generator (S12XECRGV1) 8.5.1.3 Power On Reset, Low Voltage Reset The on-chip voltage regulator detects when VDD to the MCU has reached a certain level and asserts power on reset or low voltage reset or both. As soon as a power on reset or low voltage reset is triggered the S12XECRG performs a quality check on the incoming clock signal. As soon as clock quality check indicates a valid Oscillator Clock signal the reset sequence starts using the Oscillator clock. If after 50 check windows the clock quality check indicated a non-valid Oscillator Clock the reset sequence starts using Self-Clock Mode. Figure 8-22 and Figure 8-23 show the power-up sequence for cases when the RESET pin is tied to VDD and when the RESET pin is held low. RESET Clock Quality Check (no Self-Clock Mode) )( Internal POR Internal RESET )( 128 SYSCLK )( 64 SYSCLK Figure 8-22. RESET Pin Tied to VDD (by a Pull-up Resistor) RESET Clock Quality Check (no Self Clock Mode) )( Internal POR Internal RESET )( 128 SYSCLK )( 64 SYSCLK Figure 8-23. RESET Pin Held Low Externally 8.6 Interrupts The interrupts/reset vectors requested by the S12XECRG are listed in Table 8-17. Refer to MCU specification for related vector addresses and priorities. Table 8-17. S12XECRG Interrupt Vectors Interrupt Source CCR Mask Local Enable Real time interrupt I bit CRGINT (RTIE) S12XS-Family Reference Manual, Rev. 1.03 260 PRELIMINARY Freescale Semiconductor S12XE Clocks and Reset Generator (S12XECRGV1) Table 8-17. S12XECRG Interrupt Vectors Interrupt Source CCR Mask Local Enable LOCK interrupt I bit SCM interrupt I bit CRGINT (LOCKIE) CRGINT (SCMIE) 8.6.1 Description of Interrupt Operation 8.6.1.1 Real Time Interrupt The S12XECRG generates a real time interrupt when the selected interrupt time period elapses. RTI interrupts are locally disabled by setting the RTIE bit to zero. The real time interrupt flag (RTIF) is set to1 when a timeout occurs, and is cleared to 0 by writing a 1 to the RTIF bit. The RTI continues to run during Pseudo Stop Mode if the PRE bit is set to 1. This feature can be used for periodic wakeup from Pseudo Stop if the RTI interrupt is enabled. 8.6.1.2 IPLL Lock Interrupt The S12XECRG generates a IPLL Lock interrupt when the LOCK condition of the IPLL has changed, either from a locked state to an unlocked state or vice versa. Lock interrupts are locally disabled by setting the LOCKIE bit to zero. The IPLL Lock interrupt flag (LOCKIF) is set to1 when the LOCK condition has changed, and is cleared to 0 by writing a 1 to the LOCKIF bit. 8.6.1.3 Self Clock Mode Interrupt The S12XECRG generates a Self Clock Mode interrupt when the SCM condition of the system has changed, either entered or exited Self Clock Mode. SCM conditions are caused by a failing clock quality check after power on reset (POR) or low voltage reset (LVR) or recovery from Full Stop Mode (PSTP = 0) or Clock Monitor failure. For details on the clock quality check refer to Section 8.4.1.4, “Clock Quality Checker”. If the clock monitor is enabled (CME = 1) a loss of external clock will also cause a SCM condition (SCME = 1). SCM interrupts are locally disabled by setting the SCMIE bit to zero. The SCM interrupt flag (SCMIF) is set to1 when the SCM condition has changed, and is cleared to 0 by writing a 1 to the SCMIF bit. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 261 S12XE Clocks and Reset Generator (S12XECRGV1) S12XS-Family Reference Manual, Rev. 1.03 262 PRELIMINARY Freescale Semiconductor Chapter 9 Pierce Oscillator (S12XOSCLCPV2) Revision Revision Number Date 01.05 19-Jul-06 02.00 04-Aug-06 Revision History Author Description of Changes All xclks info was removed incremented revision to match the design system spec revision 9.1 Introduction The Pierce oscillator (XOSC) module provides a robust, low-noise and low-power clock source. The module will be operated from the VDDPLL supply rail (1.8 V nominal) and require the minimum number of external components. It is designed for optimal start-up margin with typical crystal oscillators. 9.1.1 Features The XOSC will contain circuitry to dynamically control current gain in the output amplitude. This ensures a signal with low harmonic distortion, low power and good noise immunity. • High noise immunity due to input hysteresis • Low RF emissions with peak-to-peak swing limited dynamically • Transconductance (gm) sized for optimum start-up margin for typical oscillators • Dynamic gain control eliminates the need for external current limiting resistor • Integrated resistor eliminates the need for external bias resistor in loop controlled Pierce mode. • Low power consumption: — Operates from 1.8 V (nominal) supply — Amplitude control limits power • Clock monitor 9.1.2 Modes of Operation Two modes of operation exist: 1. Loop controlled Pierce (LCP) oscillator 2. External square wave mode featuring also full swing Pierce (FSP) without internal bias resistor The oscillator mode selection is described in the Device Overview section, subsection Oscillator Configuration. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 263 Pierce Oscillator (S12XOSCLCPV2) 9.1.3 Block Diagram Figure 9-1 shows a block diagram of the XOSC. Clock Monitor Monitor_Failure OSCCLK Peak Detector Gain Control VDDPLL = 1.8 V EXTAL Rf XTAL Figure 9-1. XOSC Block Diagram 9.2 External Signal Description This section lists and describes the signals that connect off chip 9.2.1 VDDPLL and VSSPLL — Operating and Ground Voltage Pins Theses pins provides operating voltage (VDDPLL) and ground (VSSPLL) for the XOSC circuitry. This allows the supply voltage to the XOSC to use an independent bypass capacitor. 9.2.2 EXTAL and XTAL — Input and Output Pins These pins provide the interface for either a crystal or a 1.8V CMOS compatible clock to control the internal clock generator circuitry. EXTAL is the external clock input or the input to the crystal oscillator amplifier. XTAL is the output of the crystal oscillator amplifier. The MCU internal system clock is derived S12XS-Family Reference Manual, Rev. 1.03 264 PRELIMINARY Freescale Semiconductor Pierce Oscillator (S12XOSCLCPV2) from the EXTAL input frequency. In full stop mode (PSTP = 0), the EXTAL pin is pulled down by an internal resistor of typical 200 kΩ. NOTE Freescale recommends an evaluation of the application board and chosen resonator or crystal by the resonator or crystal supplier. Loop controlled circuit is not suited for overtone resonators and crystals. EXTAL MCU C1 Crystal or Ceramic Resonator 晶振外围电路 XTAL C2 VSSPLL Figure 9-2. Loop Controlled Pierce Oscillator Connections (LCP mode selected) NOTE Full swing Pierce circuit is not suited for overtone resonators and crystals without a careful component selection. EXTAL C1 MCU XTAL RB RS* Crystal or Ceramic Resonator C2 VSSPLL * Rs can be zero (shorted) when use with higher frequency crystals. Refer to manufacturer’s data. Figure 9-3. Full Swing Pierce Oscillator Connections (FSP mode selected) EXTAL MCU XTAL CMOS Compatible External Oscillator (VDDPLL Level) Not Connected Figure 9-4. External Clock Connections (FSP mode selected) S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 265 Pierce Oscillator (S12XOSCLCPV2) 9.3 Memory Map and Register Definition The CRG contains the registers and associated bits for controlling and monitoring the oscillator module. 9.4 Functional Description The XOSC module has control circuitry to maintain the crystal oscillator circuit voltage level to an optimal level which is determined by the amount of hysteresis being used and the maximum oscillation range. The oscillator block has two external pins, EXTAL and XTAL. The oscillator input pin, EXTAL, is intended to be connected to either a crystal or an external clock source. The XTAL pin is an output signal that provides crystal circuit feedback. A buffered EXTAL signal becomes the internal clock. To improve noise immunity, the oscillator is powered by the VDDPLL and VSSPLL power supply pins. 9.4.1 Gain Control In LCP mode a closed loop control system will be utilized whereby the amplifier is modulated to keep the output waveform sinusoidal and to limit the oscillation amplitude. The output peak to peak voltage will be kept above twice the maximum hysteresis level of the input buffer. Electrical specification details are provided in the Electrical Characteristics appendix. 9.4.2 Clock Monitor The clock monitor circuit is based on an internal RC time delay so that it can operate without any MCU clocks. If no OSCCLK edges are detected within this RC time delay, the clock monitor indicates failure which asserts self-clock mode or generates a system reset depending on the state of SCME bit. If the clock monitor is disabled or the presence of clocks is detected no failure is indicated.The clock monitor function is enabled/disabled by the CME control bit, described in the CRG block description chapter. 9.4.3 Wait Mode Operation During wait mode, XOSC is not impacted. 9.4.4 Stop Mode Operation XOSC is placed in a static state when the part is in stop mode except when pseudo-stop mode is enabled. During pseudo-stop mode, XOSC is not impacted. S12XS-Family Reference Manual, Rev. 1.03 266 PRELIMINARY Freescale Semiconductor Chapter 10 Analog-to-Digital Converter (ADC12B16CV1) Revision History Version Revision Number Date V01.00 13 Oct. 2005 V01.01 4 Mar. 2008 Effective Date 13 Oct. 2005 4 Mar. 2008 Author Description of Changes Initial version correchted reference that DJM bit is in ATDCTL3 10.1 Introduction The ADC12B16C is a 16-channel, 12-bit, multiplexed input successive approximation analog-to-digital converter. Refer to device electrical specifications for ATD accuracy. 10.1.1 Features • 8-, 10-, or 12-bit resolution. • Conversion in Stop Mode using internally generated clock • Automatic return to low power after conversion sequence • Automatic compare with interrupt for higher than or less/equal than programmable value • Programmable sample time. • Left/right justified result data. • External trigger control. • Sequence complete interrupt. • Analog input multiplexer for 16 analog input channels. • Special conversions for VRH, VRL, (VRL+VRH)/2. • 1-to-16 conversion sequence lengths. • Continuous conversion mode. • Multiple channel scans. • Configurable external trigger functionality on any AD channel or any of four additional trigger inputs. The four additional trigger inputs can be chip external or internal. Refer to device specification for availability and connectivity. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 267 Analog-to-Digital Converter (ADC12B16CV1) • Configurable location for channel wrap around (when converting multiple channels in a sequence). S12XS-Family Reference Manual, Rev. 1.03 268 PRELIMINARY Freescale Semiconductor 10.1.2 Modes of Operation Analog-to-Digital Converter (ADC12B16CV1) 10.1.2.1 Conversion Modes There is software programmable selection between performing single or continuous conversion on a single channel or multiple channels. 10.1.2.2 MCU Operating Modes • Stop Mode — ICLKSTP=0 (in ATDCTL2 register) Entering Stop Mode aborts any conversion sequence in progress and if a sequence was aborted restarts it after exiting stop mode. This has the same effect/consequences as starting a conversion sequence with write to ATDCTL5. So after exiting from stop mode with a previously aborted sequence all flags are cleared etc. — ICLKSTP=1 (in ATDCTL2 register) A/D conversion sequence seamless continues in Stop Mode based on the internally generated clock ICLK as ATD clock. For conversions during transition from Run to Stop Mode or vice versa the result is not written to the results register, no CCF flag is set and no compare is done. When converting in Stop Mode (ICLKSTP=1) an ATD Stop Recovery time tATDSTPRCV is required to switch back to bus clock based ATDCLK when leaving Stop Mode. Do not access ATD registers during this time. • Wait Mode ADC12B16C behaves same in Run and Wait Mode. For reduced power consumption continuos conversions should be aborted before entering Wait mode. • Freeze Mode In Freeze Mode the ADC12B16C will either continue or finish or stop converting according to the FRZ1 and FRZ0 bits. This is useful for debugging and emulation. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 269 Analog-to-Digital Converter (ADC12B16CV1) 10.1.3 Block Diagram Bus Clock ETRIG0 ETRIG1 ETRIG2 ETRIG3 (See device specification for availability and connectivity) Clock Prescaler Trigger Mux ATDCTL1 ATDDIEN ICLK Internal Clock ATD Clock Mode and Timing Control ATD_12B16C Sequence Complete Interrupt Compare Interrupt VDDA VSSA VRH VRL AN15 AN14 AN13 AN12 AN11 AN10 AN9 AN8 AN7 AN6 AN5 AN4 AN3 AN2 AN1 AN0 Analog MUX Successive Approximation Register (SAR) and DAC Results ATD 0 ATD 1 ATD 2 ATD 3 ATD 4 ATD 5 ATD 6 ATD 7 ATD 8 ATD 9 ATD 10 ATD 11 ATD 12 ATD 13 ATD 14 ATD 15 Sample & Hold + Comparator Figure 10-1. ADC12B16C Block Diagram S12XS-Family Reference Manual, Rev. 1.03 270 PRELIMINARY Freescale Semiconductor 10.2 Signal Description This section lists all inputs to the ADC12B16C block. Analog-to-Digital Converter (ADC12B16CV1) 10.2.1 Detailed Signal Descriptions 10.2.1.1 ANx (x = 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0) This pin serves as the analog input Channel x. It can also be configured as digital port or external trigger for the ATD conversion. 10.2.1.2 ETRIG3, ETRIG2, ETRIG1, ETRIG0 These inputs can be configured to serve as an external trigger for the ATD conversion. Refer to device specification for availability and connection of these inputs! 10.2.1.3 VRH, VRL VRH is the high reference voltage, VRL is the low reference voltage for ATD conversion. 10.2.1.4 VDDA, VSSA These pins are the power supplies for the analog circuitry of the ADC12B16C block. 10.3 Memory Map and Register Definition This section provides a detailed description of all registers accessible in the ADC12B16C. 10.3.1 Module Memory Map Figure 10-2 gives an overview on all ADC12B16C registers. NOTE Register Address = Base Address + Address Offset, where the Base Address is defined at the MCU level and the Address Offset is defined at the module level. Address 0x0000 0x0001 0x0002 Name ATDCTL0 ATDCTL1 ATDCTL2 Bit 7 R Reserved W R ETRIGSEL W R 0 W 6 0 SRES1 AFFC 5 4 3 2 1 Bit 0 0 0 WRAP3 WRAP2 WRAP1 WRAP0 SRES0 SMP_DIS ETRIGCH3 ETRIGCH2 ETRIGCH1 ETRIGCH0 ICLKSTP ETRIGLE ETRIGP ETRIGE ASCIE ACMPIE = Unimplemented or Reserved Figure 10-2. ADC12B16C Register Summary (Sheet 1 of 3) S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 271 Analog-to-Digital Converter (ADC12B16CV1) Address Name R 0x0003 ATDCTL3 W 0x0004 ATDCTL4 R W R 0x0005 ATDCTL5 W R 0x0006 ATDSTAT0 W 0x0007 Unimple- R mented W R 0x0008 ATDCMPEH W R 0x0009 ATDCMPEL W R 0x000A ATDSTAT2H W R 0x000B ATDSTAT2L W R 0x000C ATDDIENH W 0x000D ATDDIENL R W R 0x000E ATDCMPHTH W R 0x000F ATDCMPHTL W 0x0010 R ATDDR0 W 0x0012 R ATDDR1 W 0x0014 R ATDDR2 W 0x0016 R ATDDR3 W 0x0018 R ATDDR4 W 0x001A R ATDDR5 W 0x001C ATDDR6 R W 0x001E R ATDDR7 W 0x0020 R ATDDR8 W 0x0022 R ATDDR9 W Bit 7 DJM SMP2 0 SCF 0 6 5 4 S8C S4C S2C SMP1 SMP0 SC SCAN MULT 0 ETORF FIFOR 0 0 0 3 S1C CD CC3 0 2 FIFO 1 FRZ1 PRS[4:0] CC CC2 CB CC1 0 0 CMPE[15:8] CMPE[7:0] CCF[15:8] CCF[7:0] IEN[15:8] IEN[7:0] CMPHT[15:8] CMPHT[7:0] See Section 10.3.2.12.1, “Left Justified Result Data (DJM=0)” and Section 10.3.2.12.2, “Right Justified Result Data (DJM=1)” See Section 10.3.2.12.1, “Left Justified Result Data (DJM=0)” and Section 10.3.2.12.2, “Right Justified Result Data (DJM=1)” See Section 10.3.2.12.1, “Left Justified Result Data (DJM=0)” and Section 10.3.2.12.2, “Right Justified Result Data (DJM=1)” See Section 10.3.2.12.1, “Left Justified Result Data (DJM=0)” and Section 10.3.2.12.2, “Right Justified Result Data (DJM=1)” See Section 10.3.2.12.1, “Left Justified Result Data (DJM=0)” and Section 10.3.2.12.2, “Right Justified Result Data (DJM=1)” See Section 10.3.2.12.1, “Left Justified Result Data (DJM=0)” and Section 10.3.2.12.2, “Right Justified Result Data (DJM=1)” See Section 10.3.2.12.1, “Left Justified Result Data (DJM=0)” and Section 10.3.2.12.2, “Right Justified Result Data (DJM=1)” See Section 10.3.2.12.1, “Left Justified Result Data (DJM=0)” and Section 10.3.2.12.2, “Right Justified Result Data (DJM=1)” See Section 10.3.2.12.1, “Left Justified Result Data (DJM=0)” and Section 10.3.2.12.2, “Right Justified Result Data (DJM=1)” See Section 10.3.2.12.1, “Left Justified Result Data (DJM=0)” and Section 10.3.2.12.2, “Right Justified Result Data (DJM=1)” = Unimplemented or Reserved Figure 10-2. ADC12B16C Register Summary (Sheet 2 of 3) Bit 0 FRZ0 CA CC0 0 S12XS-Family Reference Manual, Rev. 1.03 272 PRELIMINARY Freescale Semiconductor Analog-to-Digital Converter (ADC12B16CV1) Address Name R 0x0024 ATDDR10 W 0x0026 ATDDR11 R W R 0x0028 ATDDR12 W R 0x002A ATDDR13 W R 0x002C ATDDR14 W R 0x002E ATDDR15 W Bit 7 6 5 4 3 2 1 See Section 10.3.2.12.1, “Left Justified Result Data (DJM=0)” and Section 10.3.2.12.2, “Right Justified Result Data (DJM=1)” See Section 10.3.2.12.1, “Left Justified Result Data (DJM=0)” and Section 10.3.2.12.2, “Right Justified Result Data (DJM=1)” See Section 10.3.2.12.1, “Left Justified Result Data (DJM=0)” and Section 10.3.2.12.2, “Right Justified Result Data (DJM=1)” See Section 10.3.2.12.1, “Left Justified Result Data (DJM=0)” and Section 10.3.2.12.2, “Right Justified Result Data (DJM=1)” See Section 10.3.2.12.1, “Left Justified Result Data (DJM=0)” and Section 10.3.2.12.2, “Right Justified Result Data (DJM=1)” See Section 10.3.2.12.1, “Left Justified Result Data (DJM=0)” and Section 10.3.2.12.2, “Right Justified Result Data (DJM=1)” = Unimplemented or Reserved Figure 10-2. ADC12B16C Register Summary (Sheet 3 of 3) Bit 0 S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 273 Analog-to-Digital Converter (ADC12B16CV1) 10.3.2 Register Descriptions This section describes in address order all the ADC12B16C registers and their individual bits. 10.3.2.1 ATD Control Register 0 (ATDCTL0) Writes to this register will abort current conversion sequence. Module Base + 0x0000 R W Reset 7 Reserved 0 Read: Anytime 6 5 4 3 2 0 0 0 WRAP3 WRAP2 0 0 0 1 1 = Unimplemented or Reserved Figure 10-3. ATD Control Register 0 (ATDCTL0) Write: Anytime, in special modes always write 0 to Reserved Bit 7. Table 10-1. ATDCTL0 Field Descriptions Field Description 1 WRAP1 1 0 WRAP0 1 3-0 Wrap Around Channel Select Bits — These bits determine the channel for wrap around when doing multi- WRAP[3-0] channel conversions. The coding is summarized in Table 10-2. Table 10-2. Multi-Channel Wrap Around Coding WRAP3 WRAP2 WRAP1 WRAP0 0 0 0 0 0 0 0 1 0 0 1 0 0 0 1 1 0 1 0 0 0 1 0 1 0 1 1 0 0 1 1 1 1 0 0 0 1 0 0 1 1 0 1 0 1 0 1 1 1 1 0 0 1 1 0 1 1 1 1 0 1 1 1 1 Multiple Channel Conversions (MULT = 1) Wraparound to AN0 after Converting Reserved1 AN1 AN2 AN3 AN4 AN5 AN6 AN7 AN8 AN9 AN10 AN11 AN12 AN13 AN14 AN15 S12XS-Family Reference Manual, Rev. 1.03 274 PRELIMINARY Freescale Semiconductor 1If only AN0 should be converted use MULT=0. Analog-to-Digital Converter (ADC12B16CV1) 10.3.2.2 ATD Control Register 1 (ATDCTL1) Writes to this register will abort current conversion sequence. Module Base + 0x0001 7 R ETRIGSEL W Reset 0 6 SRES1 5 SRES0 4 3 2 1 0 SMP_DIS ETRIGCH3 ETRIGCH2 ETRIGCH1 ETRIGCH0 0 1 0 1 1 1 1 Figure 10-4. ATD Control Register 1 (ATDCTL1) Read: Anytime Write: Anytime Table 10-3. ATDCTL1 Field Descriptions Field Description 7 ETRIGSEL External Trigger Source Select — This bit selects the external trigger source to be either one of the AD channels or one of the ETRIG3-0 inputs. See device specification for availability and connectivity of ETRIG30 inputs. If a particular ETRIG3-0 input option is not available, writing a 1 to ETRISEL only sets the bit but has not effect, this means that one of the AD channels (selected by ETRIGCH3-0) is configured as the source for external trigger. The coding is summarized in Table 10-5. 6–5 A/D Resolution Select — These bits select the resolution of A/D conversion results. See Table 10-4 for SRES[1:0] coding. 4 SMP_DIS Discharge Before Sampling Bit 0 No discharge before sampling. 1 The internal sample capacitor is discharged before sampling the channel. This adds 2 ATD clock cycles to the sampling time. This can help to detect an open circuit instead of measuring the previous sampled channel. 3–0 External Trigger Channel Select — These bits select one of the AD channels or one of the ETRIG3-0 inputs ETRIGCH[3:0] as source for the external trigger. The coding is summarized in Table 10-5. Table 10-4. A/D Resolution Coding SRES1 0 0 1 1 SRES0 0 1 0 1 A/D Resolution 8-bit data 10-bit data 12-bit data Reserved S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 275 Analog-to-Digital Converter (ADC12B16CV1) Table 10-5. External Trigger Channel Select Coding ETRIGSEL ETRIGCH3 ETRIGCH2 ETRIGCH1 ETRIGCH0 External trigger source is 0 0 0 0 0 AN0 0 0 0 0 1 AN1 0 0 0 1 0 AN2 0 0 0 1 1 AN3 0 0 1 0 0 AN4 0 0 1 0 1 AN5 0 0 1 1 0 AN6 0 0 1 1 1 AN7 0 1 0 0 0 AN8 0 1 0 0 1 AN9 0 1 0 1 0 AN10 0 1 0 1 1 AN11 0 1 1 0 0 AN12 0 1 1 0 1 AN13 0 1 1 1 0 AN14 0 1 1 1 1 1 0 0 0 0 1 0 0 0 1 1 0 0 1 0 1 0 0 1 1 AN15 ETRIG01 ETRIG11 ETRIG21 ETRIG31 1 0 1 X X Reserved 1 1 X X X Reserved 1 Only if ETRIG3-0 input option is available (see device specification), else ETRISEL is ignored, that means external trigger source is still on one of the AD channels selected by ETRIGCH3-0 10.3.2.3 ATD Control Register 2 (ATDCTL2) Writes to this register will abort current conversion sequence. Module Base + 0x0002 7 R 0 W 6 AFFC 5 ICLKSTP 4 ETRIGLE 3 ETRIGP 2 ETRIGE Reset 0 0 0 0 0 0 = Unimplemented or Reserved Figure 10-5. ATD Control Register 2 (ATDCTL2) Read: Anytime Write: Anytime 1 ASCIE 0 0 ACMPIE 0 S12XS-Family Reference Manual, Rev. 1.03 276 PRELIMINARY Freescale Semiconductor Analog-to-Digital Converter (ADC12B16CV1) Table 10-6. ATDCTL2 Field Descriptions Field Description 6 AFFC 5 ICLKSTP 4 ETRIGLE ATD Fast Flag Clear All 0 ATD flag clearing done by write 1 to respective CCF[n] flag. 1 Changes all ATD conversion complete flags to a fast clear sequence. For compare disabled (CMPE[n]=0) a read access to the result register will cause the associated CCF[n] flag to clear automatically. For compare enabled (CMPE[n]=1) a write access to the result register will cause the associated CCF[n] flag to clear automatically. Internal Clock in Stop Mode Bit — This bit enables A/D conversions in stop mode. When going into stop mode and ICLKSTP=1 the ATD conversion clock is automatically switched to the internally generated clock ICLK. Current conversion sequence will seamless continue. Conversion speed will change from prescaled bus frequency to the ICLK frequency (see ATD Electrical Characteristics in device description). The prescaler bits PRS4-0 in ATDCTL4 have no effect on the ICLK frequency. For conversions during stop mode the automatic compare interrupt or the sequence complete interrupt can be used to inform software handler about changing A/D values. External trigger will not work while converting in stop mode. For conversions during transition from Run to Stop Mode or vice versa the result is not written to the results register, no CCF flag is set and no compare is done. When converting in Stop Mode (ICLKSTP=1) an ATD Stop Recovery time tATDSTPRCV is required to switch back to bus clock based ATDCLK when leaving Stop Mode. Do not access ATD registers during this time. 0 If A/D conversion sequence is ongoing when going into stop mode, the actual conversion sequence will be aborted and automatically restarted when exiting stop mode. 1 A/D continues to convert in stop mode using internally generated clock (ICLK) External Trigger Level/Edge Control — This bit controls the sensitivity of the external trigger signal. See Table 10-7 for details. 3 ETRIGP 2 ETRIGE 1 ASCIE 0 ACMPIE External Trigger Polarity — This bit controls the polarity of the external trigger signal. See Table 10-7 for details. External Trigger Mode Enable — This bit enables the external trigger on one of the AD channels or one of the ETRIG3-0 inputs as described in Table 10-5. If external trigger source is one of the AD channels, the digital input buffer of this channel is enabled. The external trigger allows to synchronize the start of conversion with external events. External trigger will not work while converting in stop mode. 0 Disable external trigger 1 Enable external trigger ATD Sequence Complete Interrupt Enable 0 ATD Sequence Complete interrupt requests are disabled. 1 ATD Sequence Complete interrupt will be requested whenever SCF=1 is set. ATD Compare Interrupt Enable — If automatic compare is enabled for conversion n (CMPE[n]=1 in ATDCMPE register) this bit enables the compare interrupt. If the CCF[n] flag is set (showing a successful compare for conversion n), the compare interrupt is triggered. 0 ATD Compare interrupt requests are disabled. 1 For the conversions in a sequence for which automatic compare is enabled (CMPE[n]=1), ATD Compare Interrupt will be requested whenever any of the respective CCF flags is set. Table 10-7. External Trigger Configurations ETRIGLE 0 0 1 1 ETRIGP 0 1 0 1 External Trigger Sensitivity Falling edge Rising edge Low level High level S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 277 Analog-to-Digital Converter (ADC12B16CV1) 10.3.2.4 ATD Control Register 3 (ATDCTL3) Writes to this register will abort current conversion sequence. Module Base + 0x0003 R W Reset 7 DJM 0 6 S8C 5 S4C 4 S2C 3 S1C 2 FIFO 0 1 0 0 0 = Unimplemented or Reserved Figure 10-6. ATD Control Register 3 (ATDCTL3) Read: Anytime Write: Anytime Table 10-8. ATDCTL3 Field Descriptions 1 FRZ1 0 0 FRZ0 0 Field Description 7 DJM Result Register Data Justification — Result data format is always unsigned. This bit controls justification of conversion data in the result registers. 0 Left justified data in the result registers. 1 Right justified data in the result registers. Table 10-9 gives examples ATD results for an input signal range between 0 and 5.12 Volts. 6–3 Conversion Sequence Length — These bits control the number of conversions per sequence. Table 10-10 S8C, S4C, shows all combinations. At reset, S4C is set to 1 (sequence length is 4). This is to maintain software continuity S2C, S1C to HC12 family. 2 FIFO Result Register FIFO Mode — If this bit is zero (non-FIFO mode), the A/D conversion results map into the result registers based on the conversion sequence; the result of the first conversion appears in the first result register (ATDDR0), the second result in the second result register (ATDDR1), and so on. If this bit is one (FIFO mode) the conversion counter is not reset at the beginning or ending of a conversion sequence; sequential conversion results are placed in consecutive result registers. In a continuously scanning conversion sequence, the result register counter will wrap around when it reaches the end of the result register file. The conversion counter value (CC3-0 in ATDSTAT0) can be used to determine where in the result register file, the current conversion result will be placed. Aborting a conversion or starting a new conversion clears the conversion counter even if FIFO=1. So the first result of a new conversion sequence, started by writing to ATDCTL5, will always be place in the first result register (ATDDDR0). Intended usage of FIFO mode is continuos conversion (SCAN=1) or triggered conversion (ETRIG=1). Which result registers hold valid data can be tracked using the conversion complete flags. Fast flag clear mode may or may not be useful in a particular application to track valid data. If this bit is one, automatic compare of result registers is always disabled, that is ADC12B16C will behave as if ACMPIE and all CPME[n] were zero. 0 Conversion results are placed in the corresponding result register up to the selected sequence length. 1 Conversion results are placed in consecutive result registers (wrap around at end). 1–0 FRZ[1:0] Background Debug Freeze Enable — When debugging an application, it is useful in many cases to have the ATD pause when a breakpoint (Freeze Mode) is encountered. These 2 bits determine how the ATD will respond to a breakpoint as shown in Table 10-11. Leakage onto the storage node and comparator reference capacitors may compromise the accuracy of an immediately frozen conversion depending on the length of the freeze period. S12XS-Family Reference Manual, Rev. 1.03 278 PRELIMINARY Freescale Semiconductor Analog-to-Digital Converter (ADC12B16CV1) Table 10-9. Examples of ideal decimal ATD Results Input Signal VRL = 0 Volts VRH = 5.12 Volts 5.120 Volts ... 0.022 0.020 0.018 0.016 0.014 0.012 0.010 0.008 0.006 0.004 0.003 0.002 0.000 8-Bit Codes (resolution=20mV) 10-Bit Codes (resolution=5mV) 12-Bit Codes (transfer curve has 1.25mV offset) (resolution=1.25mV) 255 1023 4095 ... ... ... 1 4 17 1 4 16 1 4 14 1 3 12 1 3 11 1 2 9 1 2 8 0 2 6 0 1 4 0 1 3 0 0 2 0 0 1 0 0 0 Table 10-10. Conversion Sequence Length Coding S8C S4C 0 0 0 0 0 0 0 0 0 1 0 1 0 1 0 1 1 0 1 0 1 0 1 0 1 1 1 1 1 1 1 1 S2C 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 S1C Number of Conversions per Sequence 0 16 1 1 0 2 1 3 0 4 1 5 0 6 1 7 0 8 1 9 0 10 1 11 0 12 1 13 0 14 1 15 S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 279 Analog-to-Digital Converter (ADC12B16CV1) Table 10-11. ATD Behavior in Freeze Mode (Breakpoint) FRZ1 0 0 1 1 FRZ0 0 1 0 1 Behavior in Freeze Mode Continue conversion Reserved Finish current conversion, then freeze Freeze Immediately 10.3.2.5 ATD Control Register 4 (ATDCTL4) Writes to this register will abort current conversion sequence. Module Base + 0x0004 7 6 5 4 3 2 1 0 R SMP2 W SMP1 SMP0 PRS[4:0] Reset 0 0 0 0 0 1 0 1 Figure 10-7. ATD Control Register 4 (ATDCTL4) Read: Anytime Write: Anytime Table 10-12. ATDCTL4 Field Descriptions Field Description 7–5 SMP[2:0] 4–0 PRS[4:0] Sample Time Select — These three bits select the length of the sample time in units of ATD conversion clock cycles. Note that the ATD conversion clock period is itself a function of the prescaler value (bits PRS4-0). Table 10-13 lists the available sample time lengths. ATD Clock Prescaler — These 5 bits are the binary prescaler value PRS. The ATD conversion clock frequency is calculated as follows: fATDCLK = 2-----×-----(--f-P-B---R-U----S-S----+-----1-----) Refer to Device Specification for allowed frequency range of fATDCLK. SMP2 0 0 0 0 1 1 1 Table 10-13. Sample Time Select SMP1 0 0 1 1 0 0 1 SMP0 0 1 0 1 0 1 0 Sample Time in Number of ATD Clock Cycles 4 6 8 10 12 16 20 S12XS-Family Reference Manual, Rev. 1.03 280 PRELIMINARY Freescale Semiconductor SMP2 1 Analog-to-Digital Converter (ADC12B16CV1) Table 10-13. Sample Time Select SMP1 1 SMP0 1 Sample Time in Number of ATD Clock Cycles 24 10.3.2.6 ATD Control Register 5 (ATDCTL5) Writes to this register will abort current conversion sequence and start a new conversion sequence. If external trigger is enabled (ETRIGE=1) an initial write to ATDCTL5 is required to allow starting of a conversion sequence which will then occur on each trigger event. Start of conversion means the beginning of the sampling phase. Module Base + 0x0005 7 R 0 W Reset 0 6 5 4 3 2 1 0 SC SCAN MULT CD CC CB CA 0 0 0 0 0 0 0 Figure 10-8. ATD Control Register 5 (ATDCTL5) Read: Anytime Write: Anytime Table 10-14. ATDCTL5 Field Descriptions Field 6 SC 5 SCAN Description Special Channel Conversion Bit — If this bit is set, then special channel conversion can be selected using CD, CC, CB and CA of ATDCTL5. Table 10-15 lists the coding. 0 Special channel conversions disabled 1 Special channel conversions enabled Continuous Conversion Sequence Mode — This bit selects whether conversion sequences are performed continuously or only once. If external trigger is enabled (ETRIGE=1) setting this bit has no effect, that means external trigger always starts a single conversion sequence. 0 Single conversion sequence 1 Continuous conversion sequences (scan mode) S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 281 Analog-to-Digital Converter (ADC12B16CV1) Table 10-14. ATDCTL5 Field Descriptions (continued) Field 4 MULT 3–0 CD, CC, CB, CA Description Multi-Channel Sample Mode — When MULT is 0, the ATD sequence controller samples only from the specified analog input channel for an entire conversion sequence. The analog channel is selected by channel selection code (control bits CD/CC/CB/CA located in ATDCTL5). When MULT is 1, the ATD sequence controller samples across channels. The number of channels sampled is determined by the sequence length value (S8C, S4C, S2C, S1C). The first analog channel examined is determined by channel selection code (CD, CC, CB, CA control bits); subsequent channels sampled in the sequence are determined by incrementing the channel selection code or wrapping around to AN0 (channel 0). 0 Sample only one channel 1 Sample across several channels Analog Input Channel Select Code — These bits select the analog input channel(s) whose signals are sampled and converted to digital codes. Table 10-15 lists the coding used to select the various analog input channels. In the case of single channel conversions (MULT=0), this selection code specifies the channel to be examined. In the case of multiple channel conversions (MULT=1), this selection code specifies the first channel to be examined in the conversion sequence. Subsequent channels are determined by incrementing the channel selection code or wrapping around to AN0 (after converting the channel defined by the Wrap Around Channel Select Bits WRAP3-0 in ATDCTL0). In case of starting with a channel number higher than the one defined by WRAP3-0 the first wrap around will be AN15 to AN0. Table 10-15. Analog Input Channel Select Coding SC CD CC CB CA 0 0 0 0 0 0 0 0 1 0 0 1 0 0 0 1 1 0 1 0 0 0 1 0 1 0 1 1 0 0 1 1 1 1 0 0 0 1 0 0 1 1 0 1 0 1 0 1 1 1 1 0 0 1 1 0 1 1 1 1 0 1 1 1 1 Analog Input Channel AN0 AN1 AN2 AN3 AN4 AN5 AN6 AN7 AN8 AN9 AN10 AN11 AN12 AN13 AN14 AN15 S12XS-Family Reference Manual, Rev. 1.03 282 PRELIMINARY Freescale Semiconductor Analog-to-Digital Converter (ADC12B16CV1) Table 10-15. Analog Input Channel Select Coding SC CD CC CB CA 1 0 0 0 0 0 0 0 1 0 0 1 X 0 1 0 0 0 1 0 1 0 1 1 0 0 1 1 1 1 X X X Analog Input Channel Reserved Reserved Reserved VRH VRL (VRH+VRL) / 2 Reserved Reserved S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 283 Analog-to-Digital Converter (ADC12B16CV1) 10.3.2.7 ATD Status Register 0 (ATDSTAT0) This register contains the Sequence Complete Flag, overrun flags for external trigger and FIFO mode, and the conversion counter. Module Base + 0x0006 7 R SCF W 6 5 4 3 2 1 0 0 CC3 CC2 CC1 CC0 ETORF FIFOR Reset 0 0 0 0 0 0 0 0 = Unimplemented or Reserved Figure 10-9. ATD Status Register 0 (ATDSTAT0) Read: Anytime Write: Anytime (No effect on (CC3, CC2, CC1, CC0)) Table 10-16. ATDSTAT0 Field Descriptions Field 7 SCF 5 ETORF 4 FIFOR Description Sequence Complete Flag — This flag is set upon completion of a conversion sequence. If conversion sequences are continuously performed (SCAN=1), the flag is set after each one is completed. This flag is cleared when one of the following occurs: A) Write “1” to SCF B) Write to ATDCTL5 (a new conversion sequence is started) C) If AFFC=1 and read of a result register 0 Conversion sequence not completed 1 Conversion sequence has completed External Trigger Overrun Flag — While in edge trigger mode (ETRIGLE=0), if additional active edges are detected while a conversion sequence is in process the overrun flag is set. This flag is cleared when one of the following occurs: A) Write “1” to ETORF B) Write to ATDCTL0,1,2,3,4, ATDCMPE or ATDCMPHT (a conversion sequence is aborted) C) Write to ATDCTL5 (a new conversion sequence is started) 0 No External trigger over run error has occurred 1 External trigger over run error has occurred Result Register Over Run Flag — This bit indicates that a result register has been written to before its associated conversion complete flag (CCF) has been cleared. This flag is most useful when using the FIFO mode because the flag potentially indicates that result registers are out of sync with the input channels. However, it is also practical for non-FIFO modes, and indicates that a result register has been over written before it has been read (i.e. the old data has been lost). This flag is cleared when one of the following occurs: A) Write “1” to FIFOR B) Write to ATDCTL0,1,2,3,4, ATDCMPE or ATDCMPHT (a conversion sequence is aborted) C) Write to ATDCTL5 (a new conversion sequence is started) 0 No over run has occurred 1 Overrun condition exists (result register has been written while associated CCFx flag was still set) S12XS-Family Reference Manual, Rev. 1.03 284 PRELIMINARY Freescale Semiconductor Analog-to-Digital Converter (ADC12B16CV1) Table 10-16. ATDSTAT0 Field Descriptions (continued) Field 3–0 CC[3:0] Description Conversion Counter — These 4 read-only bits are the binary value of the conversion counter. The conversion counter points to the result register that will receive the result of the current conversion. E.g. CC3=0, CC2=1, CC1=1, CC0=0 indicates that the result of the current conversion will be in ATD Result Register 6. If in non-FIFO mode (FIFO=0) the conversion counter is initialized to zero at the begin and end of the conversion sequence. If in FIFO mode (FIFO=1) the register counter is not initialized. The conversion counters wraps around when its maximum value is reached. Aborting a conversion or starting a new conversion clears the conversion counter even if FIFO=1. 10.3.2.8 ATD Compare Enable Register (ATDCMPE) Writes to this register will abort current conversion sequence. Read: Anytime Write: Anytime Module Base + 0x0008 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 R CMPE[15:0] W Reset 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Figure 10-10. ATD Compare Enable Register (ATDCMPE) Table 10-17. ATDCMPE Field Descriptions Field Description 15–0 Compare Enable for Conversion Number n (n= 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0) of a Sequence CMPE[15:0] — These bits enable automatic compare of conversion results individually for conversions of a sequence. The sense of each comparison is determined by the CMPHT[n] bit in the ATDCMPHT register. For each conversion number with CMPE[n]=1 do the following: 1) Write compare value to ATDDRn result register 2) Write compare operator with CMPHT[n] in ATDCPMHT register CCF[n] in ATDSTAT2 register will flag individual success of any comparison. 0 No automatic compare 1 Automatic compare of results for conversion n of a sequence is enabled. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 285 Analog-to-Digital Converter (ADC12B16CV1) 10.3.2.9 ATD Status Register 2 (ATDSTAT2) This read-only register contains the Conversion Complete Flags CCF[15:0]. Module Base + 0x000A 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 R CCF[15:0] W Reset 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 = Unimplemented or Reserved Figure 10-11. ATD Status Register 2 (ATDSTAT2) Read: Anytime Write: Anytime, no effect Table 10-18. ATDSTAT2 Field Descriptions Field Description 15–0 CCF[15:0] Conversion Complete Flag n (n= 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0) — A conversion complete flag is set at the end of each conversion in a sequence. The flags are associated with the conversion position in a sequence (and also the result register number). Therefore in non-fifo mode, CCF[8] is set when the ninth conversion in a sequence is complete and the result is available in result register ATDDR8; CCF[9] is set when the tenth conversion in a sequence is complete and the result is available in ATDDR9, and so forth. If automatic compare of conversion results is enabled (CMPE[n]=1 in ATDCMPE), the conversion complete flag is only set if comparison with ATDDRn is true and if ACMPIE=1 a compare interrupt will be requested. In this case, as the ATDDRn result register is used to hold the compare value, the result will not be stored there at the end of the conversion but is lost. A flag CCF[n] is cleared when one of the following occurs: A) Write to ATDCTL5 (a new conversion sequence is started) B) If AFFC=0, write “1” to CCF[n] C) If AFFC=1 and CMPE[n]=0, read of result register ATDDRn D) If AFFC=1 and CMPE[n]=1, write to result register ATDDRn In case of a concurrent set and clear on CCF[n]: The clearing by method A) will overwrite the set. The clearing by methods B) or C) or D) will be overwritten by the set. 0 Conversion number n not completed or successfully compared 1 If (CMPE[n]=0): Conversion number n has completed. Result is ready in ATDDRn. If (CMPE[n]=1): Compare for conversion result number n with compare value in ATDDRn, using compare operator CMPGT[n] is true. (No result available in ATDDRn) S12XS-Family Reference Manual, Rev. 1.03 286 PRELIMINARY Freescale Semiconductor Analog-to-Digital Converter (ADC12B16CV1) 10.3.2.10 ATD Input Enable Register (ATDDIEN) Module Base + 0x000C 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 R IEN[15:0] W Reset 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Figure 10-12. ATD Input Enable Register (ATDDIEN) Read: Anytime Write: Anytime Table 10-19. ATDDIEN Field Descriptions Field Description 15–0 IEN[15:0] ATD Digital Input Enable on channel x (x= 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0) — This bit controls the digital input buffer from the analog input pin (ANx) to the digital data register. 0 Disable digital input buffer to ANx pin 1 Enable digital input buffer on ANx pin. Note: Setting this bit will enable the corresponding digital input buffer continuously. If this bit is set while simultaneously using it as an analog port, there is potentially increased power consumption because the digital input buffer maybe in the linear region. 10.3.2.11 ATD Compare Higher Than Register (ATDCMPHT) Writes to this register will abort current conversion sequence. Read: Anytime Write: Anytime Module Base + 0x000E 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 R CMPHT[15:0] W Reset 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Figure 10-13. ATD Compare Higher Than Register (ATDCMPHT) Table 10-20. ATDCMPHT Field Descriptions Field Description 15–0 Compare Operation Higher Than Enable for conversion number n (n= 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, CMPHT[15:0] 4, 3, 2, 1, 0) of a Sequence — This bit selects the operator for comparison of conversion results. 0 If result of conversion n is lower or same than compare value in ATDDRn, this is flagged in ATDSTAT2 1 If result of conversion n is higher than compare value in ATDDRn, this is flagged in ATDSTAT2 S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 287 Analog-to-Digital Converter (ADC12B16CV1) 10.3.2.12 ATD Conversion Result Registers (ATDDRn) The A/D conversion results are stored in 16 result registers. Results are always in unsigned data representation. Left and right justification is selected using the DJM control bit in ATDCTL3. If automatic compare of conversions results is enabled (CMPE[n]=1 in ATDCMPE), these registers must be written with the compare values in left or right justified format depending on the actual value of the DJM bit. In this case, as the ATDDRn register is used to hold the compare value, the result will not be stored there at the end of the conversion but is lost. Read: Anytime Write: Anytime NOTE For conversions not using automatic compare, results are stored in the result registers after each conversion. In this case avoid writing to ATDDRn except for initial values, because an A/D result might be overwritten. 10.3.2.12.1 Left Justified Result Data (DJM=0) Module Base + 0x0010 = ATDDR0, 0x0012 = ATDDR1, 0x0014 = ATDDR2, 0x0016 = ATDDR3 0x0018 = ATDDR4, 0x001A = ATDDR5, 0x001C = ATDDR6, 0x001E = ATDDR7 0x0020 = ATDDR8, 0x0022 = ATDDR9, 0x0024 = ATDDR10, 0x0026 = ATDDR11 0x0028 = ATDDR12, 0x002A = ATDDR13, 0x002C = ATDDR14, 0x002E = ATDDR15 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 R 0 0 0 0 Bit 11 Bit 10 Bit 9 Bit 8 Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 W Reset 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Figure 10-14. Left justified ATD conversion result register (ATDDRn) 10.3.2.12.2 Right Justified Result Data (DJM=1) Module Base + 0x0010 = ATDDR0, 0x0012 = ATDDR1, 0x0014 = ATDDR2, 0x0016 = ATDDR3 0x0018 = ATDDR4, 0x001A = ATDDR5, 0x001C = ATDDR6, 0x001E = ATDDR7 0x0020 = ATDDR8, 0x0022 = ATDDR9, 0x0024 = ATDDR10, 0x0026 = ATDDR11 0x0028 = ATDDR12, 0x002A = ATDDR13, 0x002C = ATDDR14, 0x002E = ATDDR15 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 R0 0 0 0 Bit 11 Bit 10 Bit 9 Bit 8 Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bi1 1 Bit 0 W Reset 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Figure 10-15. Right justified ATD conversion result register (ATDDRn) Table 10-15 shows how depending on the A/D resolution the conversion result is transferred to the ATD result registers. Compare is always done using all 12 bits of both the conversion result and the compare value in ATDDRn. S12XS-Family Reference Manual, Rev. 1.03 288 PRELIMINARY Freescale Semiconductor Analog-to-Digital Converter (ADC12B16CV1) Table 10-21. Conversion result mapping to ATDDRn A/D resolution DJM conversion result mapping to ATDDRn 8-bit data 0 8-bit data 1 10-bit data 0 10-bit data 1 12-bit data X Bit[11:4] = result, Bit[3:0]=0000 Bit[7:0] = result, Bit[11:8]=0000 Bit[11:2] = result, Bit[1:0]=00 Bit[9:0] = result, Bit[11:10]=00 Bit[11:0] = result S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 289 Analog-to-Digital Converter (ADC12B16CV1) 10.4 Functional Description The ADC12B16C is structured into an analog sub-block and a digital sub-block. 10.4.1 Analog Sub-Block The analog sub-block contains all analog electronics required to perform a single conversion. Separate power supplies VDDA and VSSA allow to isolate noise of other MCU circuitry from the analog sub-block. 10.4.1.1 Sample and Hold Machine The Sample and Hold (S/H) Machine accepts analog signals from the external world and stores them as capacitor charge on a storage node. During the sample process the analog input connects directly to the storage node. The input analog signals are unipolar and must fall within the potential range of VSSA to VDDA. During the hold process the analog input is disconnected from the storage node. 10.4.1.2 Analog Input Multiplexer The analog input multiplexer connects one of the 16 external analog input channels to the sample and hold machine. 10.4.1.3 Analog-to-Digital (A/D) Machine The A/D Machine performs analog to digital conversions. The resolution is program selectable at either 8 or 10 or 12 bits. The A/D machine uses a successive approximation architecture. It functions by comparing the stored analog sample potential with a series of digitally generated analog potentials. By following a binary search algorithm, the A/D machine locates the approximating potential that is nearest to the sampled potential. When not converting the A/D machine is automatically powered down. Only analog input signals within the potential range of VRL to VRH (A/D reference potentials) will result in a non-railed digital output code. 10.4.2 Digital Sub-Block This subsection explains some of the digital features in more detail. See Section 10.3.2, “Register Descriptions” for all details. 10.4.2.1 External Trigger Input The external trigger feature allows the user to synchronize ATD conversions to the external environment events rather than relying on software to signal the ATD module when ATD conversions are to take place. The external trigger signal (out of reset ATD channel 15, configurable in ATDCTL1) is programmable to S12XS-Family Reference Manual, Rev. 1.03 290 PRELIMINARY Freescale Semiconductor Analog-to-Digital Converter (ADC12B16CV1) be edge or level sensitive with polarity control. Table 10-22 gives a brief description of the different combinations of control bits and their effect on the external trigger function. ETRIGLE X X 0 0 1 1 Table 10-22. External Trigger Control Bits ETRIGP X X 0 1 0 1 ETRIGE 0 0 1 1 1 1 SCAN Description 0 Ignores external trigger. Performs one conversion sequence and stops. 1 Ignores external trigger. Performs continuous conversion sequences. X Falling edge triggered. Performs one conversion sequence per trigger. X Rising edge triggered. Performs one conversion sequence per trigger. X Trigger active low. Performs continuous conversions while trigger is active. X Trigger active high. Performs continuous conversions while trigger is active. During a conversion, if additional active edges are detected the overrun error flag ETORF is set. In either level or edge triggered modes, the first conversion begins when the trigger is received. Once ETRIGE is enabled, conversions cannot be started by a write to ATDCTL5, but rather must be triggered externally. If the level mode is active and the external trigger both de-asserts and re-asserts itself during a conversion sequence, this does not constitute an overrun. Therefore, the flag is not set. If the trigger is left asserted in level mode while a sequence is completing, another sequence will be triggered immediately. 10.4.2.2 General-Purpose Digital Port Operation The input channel pins can be multiplexed between analog and digital data. As analog inputs, they are multiplexed and sampled as analog channels to the A/D converter. The analog/digital multiplex operation is performed in the input pads. The input pad is always connected to the analog input channels of the ADC12B16C. The input pad signal is buffered to the digital port registers. This buffer can be turned on or off with the ATDDIEN register. This is important so that the buffer does not draw excess current when analog potentials are presented at its input. 10.5 Resets At reset the ADC12B16C is in a power down state. The reset state of each individual bit is listed within the Register Description section (see Section 10.3.2, “Register Descriptions”) which details the registers and their bit-field. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 291 Analog-to-Digital Converter (ADC12B16CV1) 10.6 Interrupts The interrupts requested by the ADC12B16C are listed in Table 10-23. Refer to MCU specification for related vector address and priority. Table 10-23. ATD Interrupt Vectors Interrupt Source Sequence Complete Interrupt Compare Interrupt CCR Mask I bit I bit Local Enable ASCIE in ATDCTL2 ACMPIE in ATDCTL2 See Section 10.3.2, “Register Descriptions” for further details. S12XS-Family Reference Manual, Rev. 1.03 292 PRELIMINARY Freescale Semiconductor Chapter 11 Freescale’s Scalable Controller Area Network (S12MSCANV3) Table 11-1. Revision History Revision Number Revision Date V03.07 V03.08 V03.09 06 Feb 2006 07 Mar 2006 04 May 2007 Sections Affected Description of Changes - Internal updates only. - Internal updates only. 11.3.2.11/11- - Corrected mnemonics of code example in CANTBSEL register description 311 11.1 Introduction Freescale’s scalable controller area network (S12MSCANV3) definition is based on the MSCAN12 definition, which is the specific implementation of the MSCAN concept targeted for the M68HC12 microcontroller family. The module is a communication controller implementing the CAN 2.0A/B protocol as defined in the Bosch specification dated September 1991. For users to fully understand the MSCAN specification, it is recommended that the Bosch specification be read first to familiarize the reader with the terms and concepts contained within this document. Though not exclusively intended for automotive applications, CAN protocol is designed to meet the specific requirements of a vehicle serial data bus: real-time processing, reliable operation in the EMI environment of a vehicle, cost-effectiveness, and required bandwidth. MSCAN uses an advanced buffer arrangement resulting in predictable real-time behavior and simplified application software. 11.1.1 Glossary ACK: Acknowledge of CAN message CAN: Controller Area Network CRC: Cyclic Redundancy Code EOF: End of Frame FIFO: First-In-First-Out Memory S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 293 Freescale’s Scalable Controller Area Network (S12MSCANV3) IFS: Inter-Frame Sequence SOF: Start of Frame CPU bus: CPU related read/write data bus CAN bus: CAN protocol related serial bus oscillator clock: Direct clock from external oscillator bus clock: CPU bus realated clock CAN clock: CAN protocol related clock 11.1.2 Block Diagram Oscillator Clock Bus Clock MSCAN CANCLK Tq Clk MUX Presc. Receive/ Transmit Engine RXCAN TXCAN Transmit Interrupt Req. Receive Interrupt Req. Errors Interrupt Req. Wake-Up Interrupt Req. Control and Status Configuration Registers Message Filtering and Buffering Wake-Up Low Pass Filter Figure 11-1. MSCAN Block Diagram 11.1.3 Features The basic features of the MSCAN are as follows: • Implementation of the CAN protocol — Version 2.0A/B — Standard and extended data frames — Zero to eight bytes data length — Programmable bit rate up to 1 Mbps1 — Support for remote frames • Five receive buffers with FIFO storage scheme • Three transmit buffers with internal prioritization using a “local priority” concept 1. Depending on the actual bit timing and the clock jitter of the PLL. S12XS-Family Reference Manual, Rev. 1.03 294 PRELIMINARY Freescale Semiconductor Freescale’s Scalable Controller Area Network (S12MSCANV3) • Flexible maskable identifier filter supports two full-size (32-bit) extended identifier filters, or four 16-bit filters, or eight 8-bit filters • Programmable wakeup functionality with integrated low-pass filter • Programmable loopback mode supports self-test operation • Programmable listen-only mode for monitoring of CAN bus • Programmable bus-off recovery functionality • Separate signalling and interrupt capabilities for all CAN receiver and transmitter error states (warning, error passive, bus-off) • Programmable MSCAN clock source either bus clock or oscillator clock • Internal timer for time-stamping of received and transmitted messages • Three low-power modes: sleep, power down, and MSCAN enable • Global initialization of configuration registers 11.1.4 Modes of Operation The following modes of operation are specific to the MSCAN. See Section 11.4, “Functional Description,” for details. • Listen-Only Mode • MSCAN Sleep Mode • MSCAN Initialization Mode • MSCAN Power Down Mode 11.2 External Signal Description The MSCAN uses two external pins: 11.2.1 RXCAN — CAN Receiver Input Pin RXCAN is the MSCAN receiver input pin. 11.2.2 TXCAN — CAN Transmitter Output Pin TXCAN is the MSCAN transmitter output pin. The TXCAN output pin represents the logic level on the CAN bus: 0 = Dominant state 1 = Recessive state 11.2.3 CAN System A typical CAN system with MSCAN is shown in Figure 11-2. Each CAN station is connected physically to the CAN bus lines through a transceiver device. The transceiver is capable of driving the large current needed for the CAN bus and has current protection against defective CAN or defective stations. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 295 Freescale’s Scalable Controller Area Network (S12MSCANV3) CAN node 1 MCU CAN Controller (MSCAN) CAN node 2 CAN node n TXCAN RXCAN Transceiver CAN_H CAN_L CAN Bus Figure 11-2. CAN System 11.3 Memory Map and Register Definition This section provides a detailed description of all registers accessible in the MSCAN. 11.3.1 Module Memory Map Figure 11-3 gives an overview on all registers and their individual bits in the MSCAN memory map. The register address results from the addition of base address and address offset. The base address is determined at the MCU level and can be found in the MCU memory map description. The address offset is defined at the module level. The MSCAN occupies 64 bytes in the memory space. The base address of the MSCAN module is determined at the MCU level when the MCU is defined. The register decode map is fixed and begins at the first address of the module address offset. The detailed register descriptions follow in the order they appear in the register map. Register Name 0x0000 CANCTL0 0x0001 CANCTL1 Bit 7 6 5 4 3 R RXFRM W R CANE W RXACT CLKSRC CSWAI LOOPB SYNCH LISTEN TIME BORM 2 1 Bit 0 WUPE SLPRQ INITRQ WUPM SLPAK INITAK = Unimplemented or Reserved u = Unaffected Figure 11-3. MSCAN Register Summary S12XS-Family Reference Manual, Rev. 1.03 296 PRELIMINARY Freescale Semiconductor Freescale’s Scalable Controller Area Network (S12MSCANV3) Register Name 0x0002 CANBTR0 Bit 7 R SJW1 W 6 SJW0 5 BRP5 4 BRP4 3 BRP3 2 BRP2 1 BRP1 Bit 0 BRP0 0x0003 CANBTR1 R SAMP W TSEG22 TSEG21 TSEG20 TSEG13 TSEG12 TSEG11 TSEG10 0x0004 CANRFLG R WUPIF W CSCIF RSTAT1 RSTAT0 TSTAT1 TSTAT0 OVRIF RXF 0x0005 CANRIER R WUPIE W CSCIE RSTATE1 RSTATE0 TSTATE1 TSTATE0 OVRIE RXFIE 0x0006 R 0 0 0 0 0 CANTFLG W TXE2 TXE1 TXE0 0x0007 R 0 0 0 0 0 CANTIER W TXEIE2 TXEIE1 TXEIE0 0x0008 R 0 0 0 0 0 CANTARQ W ABTRQ2 ABTRQ1 ABTRQ0 0x0009 R 0 0 0 0 0 ABTAK2 ABTAK1 ABTAK0 CANTAAK W 0x000A R 0 0 0 0 0 CANTBSEL W TX2 TX1 TX0 0x000B CANIDAC R 0 W 0 0 IDHIT2 IDHIT1 IDHIT0 IDAM1 IDAM0 0x000C R 0 0 0 0 0 0 0 0 Reserved W 0x000D R 0 0 0 0 0 0 0 CANMISC W BOHOLD 0x000E CANRXERR R RXERR7 RXERR6 RXERR5 RXERR4 RXERR3 RXERR2 RXERR1 RXERR0 W 0x000F CANTXERR R TXERR7 W TXERR6 TXERR5 TXERR4 TXERR3 TXERR2 TXERR1 TXERR0 0x0010–0x0013 R CANIDAR0–3 W AC7 AC6 AC5 AC4 AC3 AC2 AC1 AC0 = Unimplemented or Reserved u = Unaffected Figure 11-3. MSCAN Register Summary (continued) S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 297 Freescale’s Scalable Controller Area Network (S12MSCANV3) Register Name 0x0014–0x0017 R CANIDMRx W Bit 7 AM7 6 AM6 5 AM5 4 AM4 3 AM3 2 AM2 1 AM1 0x0018–0x001B R CANIDAR4–7 W AC7 AC6 AC5 AC4 AC3 AC2 AC1 0x001C–0x001F R CANIDMR4–7 W AM7 AM6 AM5 AM4 AM3 AM2 AM1 0x0020–0x002F R CANRXFG W See Section 11.3.3, “Programmer’s Model of Message Storage” 0x0030–0x003F R CANTXFG W See Section 11.3.3, “Programmer’s Model of Message Storage” = Unimplemented or Reserved u = Unaffected Figure 11-3. MSCAN Register Summary (continued) Bit 0 AM0 AC0 AM0 11.3.2 Register Descriptions This section describes in detail all the registers and register bits in the MSCAN module. Each description includes a standard register diagram with an associated figure number. Details of register bit and field function follow the register diagrams, in bit order. All bits of all registers in this module are completely synchronous to internal clocks during a register read. 11.3.2.1 MSCAN Control Register 0 (CANCTL0) The CANCTL0 register provides various control bits of the MSCAN module as described below. Module Base + 0x0000 7 R RXFRM W 6 RXACT 5 CSWAI 4 SYNCH 3 TIME 2 WUPE 1 SLPRQ Reset: 0 0 0 0 0 0 0 = Unimplemented Figure 11-4. MSCAN Control Register 0 (CANCTL0) NOTE The CANCTL0 register, except WUPE, INITRQ, and SLPRQ, is held in the reset state when the initialization mode is active (INITRQ = 1 and INITAK = 1). This register is writable again as soon as the initialization mode is exited (INITRQ = 0 and INITAK = 0). Read: Anytime 0 INITRQ 1 S12XS-Family Reference Manual, Rev. 1.03 298 PRELIMINARY Freescale Semiconductor Freescale’s Scalable Controller Area Network (S12MSCANV3) Write: Anytime when out of initialization mode; exceptions are read-only RXACT and SYNCH, RXFRM (which is set by the module only), and INITRQ (which is also writable in initialization mode). Table 11-2. CANCTL0 Register Field Descriptions Field Description 7 RXFRM1 6 RXACT 5 CSWAI3 4 SYNCH 3 TIME 2 WUPE4 Received Frame Flag — This bit is read and clear only. It is set when a receiver has received a valid message correctly, independently of the filter configuration. After it is set, it remains set until cleared by software or reset. Clearing is done by writing a 1. Writing a 0 is ignored. This bit is not valid in loopback mode. 0 No valid message was received since last clearing this flag 1 A valid message was received since last clearing of this flag Receiver Active Status — This read-only flag indicates the MSCAN is receiving a message. The flag is controlled by the receiver front end. This bit is not valid in loopback mode. 0 MSCAN is transmitting or idle2 1 MSCAN is receiving a message (including when arbitration is lost)2 CAN Stops in Wait Mode — Enabling this bit allows for lower power consumption in wait mode by disabling all the clocks at the CPU bus interface to the MSCAN module. 0 The module is not affected during wait mode 1 The module ceases to be clocked during wait mode Synchronized Status — This read-only flag indicates whether the MSCAN is synchronized to the CAN bus and able to participate in the communication process. It is set and cleared by the MSCAN. 0 MSCAN is not synchronized to the CAN bus 1 MSCAN is synchronized to the CAN bus Timer Enable — This bit activates an internal 16-bit wide free running timer which is clocked by the bit clock rate. If the timer is enabled, a 16-bit time stamp will be assigned to each transmitted/received message within the active TX/RX buffer. Right after the EOF of a valid message on the CAN bus, the time stamp is written to the highest bytes (0x000E, 0x000F) in the appropriate buffer (see Section 11.3.3, “Programmer’s Model of Message Storage”). The internal timer is reset (all bits set to 0) when disabled. This bit is held low in initialization mode. 0 Disable internal MSCAN timer 1 Enable internal MSCAN timer Wake-Up Enable — This configuration bit allows the MSCAN to restart from sleep mode when traffic on CAN is detected (see Section 11.4.5.4, “MSCAN Sleep Mode”). This bit must be configured before sleep mode entry for the selected function to take effect. 0 Wake-up disabled — The MSCAN ignores traffic on CAN 1 Wake-up enabled — The MSCAN is able to restart S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 299 Freescale’s Scalable Controller Area Network (S12MSCANV3) Table 11-2. CANCTL0 Register Field Descriptions (continued) Field Description 1 SLPRQ5 Sleep Mode Request — This bit requests the MSCAN to enter sleep mode, which is an internal power saving mode (see Section 11.4.5.4, “MSCAN Sleep Mode”). The sleep mode request is serviced when the CAN bus is idle, i.e., the module is not receiving a message and all transmit buffers are empty. The module indicates entry to sleep mode by setting SLPAK = 1 (see Section 11.3.2.2, “MSCAN Control Register 1 (CANCTL1)”). SLPRQ cannot be set while the WUPIF flag is set (see Section 11.3.2.5, “MSCAN Receiver Flag Register (CANRFLG)”). Sleep mode will be active until SLPRQ is cleared by the CPU or, depending on the setting of WUPE, the MSCAN detects activity on the CAN bus and clears SLPRQ itself. 0 Running — The MSCAN functions normally 1 Sleep mode request — The MSCAN enters sleep mode when CAN bus idle 0 INITRQ6,7 Initialization Mode Request — When this bit is set by the CPU, the MSCAN skips to initialization mode (see Section 11.4.5.5, “MSCAN Initialization Mode”). Any ongoing transmission or reception is aborted and synchronization to the CAN bus is lost. The module indicates entry to initialization mode by setting INITAK = 1 (Section 11.3.2.2, “MSCAN Control Register 1 (CANCTL1)”). The following registers enter their hard reset state and restore their default values: CANCTL08, CANRFLG9, CANRIER10, CANTFLG, CANTIER, CANTARQ, CANTAAK, and CANTBSEL. The registers CANCTL1, CANBTR0, CANBTR1, CANIDAC, CANIDAR0-7, and CANIDMR0-7 can only be written by the CPU when the MSCAN is in initialization mode (INITRQ = 1 and INITAK = 1). The values of the error counters are not affected by initialization mode. When this bit is cleared by the CPU, the MSCAN restarts and then tries to synchronize to the CAN bus. If the MSCAN is not in bus-off state, it synchronizes after 11 consecutive recessive bits on the CAN bus; if the MSCAN is in bus-off state, it continues to wait for 128 occurrences of 11 consecutive recessive bits. Writing to other bits in CANCTL0, CANRFLG, CANRIER, CANTFLG, or CANTIER must be done only after initialization mode is exited, which is INITRQ = 0 and INITAK = 0. 0 Normal operation 1 MSCAN in initialization mode 1 The MSCAN must be in normal mode for this bit to become set. 2 See the Bosch CAN 2.0A/B specification for a detailed definition of transmitter and receiver states. 3 In order to protect from accidentally violating the CAN protocol, the TXCAN pin is immediately forced to a recessive state when the CPU enters wait (CSWAI = 1) or stop mode (see Section 11.4.5.2, “Operation in Wait Mode” and Section 11.4.5.3, “Operation in Stop Mode”). 4 The CPU has to make sure that the WUPE register and the WUPIE wake-up interrupt enable register (see Section 11.3.2.6, “MSCAN Receiver Interrupt Enable Register (CANRIER)) is enabled, if the recovery mechanism from stop or wait is required. 5 The CPU cannot clear SLPRQ before the MSCAN has entered sleep mode (SLPRQ = 1 and SLPAK = 1). 6 The CPU cannot clear INITRQ before the MSCAN has entered initialization mode (INITRQ = 1 and INITAK = 1). 7 In order to protect from accidentally violating the CAN protocol, the TXCAN pin is immediately forced to a recessive state when the initialization mode is requested by the CPU. Thus, the recommended procedure is to bring the MSCAN into sleep mode (SLPRQ = 1 and SLPAK = 1) before requesting initialization mode. 8 Not including WUPE, INITRQ, and SLPRQ. 9 TSTAT1 and TSTAT0 are not affected by initialization mode. 10 RSTAT1 and RSTAT0 are not affected by initialization mode. 11.3.2.2 MSCAN Control Register 1 (CANCTL1) The CANCTL1 register provides various control bits and handshake status information of the MSCAN module as described below. S12XS-Family Reference Manual, Rev. 1.03 300 PRELIMINARY Freescale Semiconductor Freescale’s Scalable Controller Area Network (S12MSCANV3) Module Base 0x0001 + R W Reset: 7 CANE 0 6 CLKSRC 5 LOOPB 0 0 = Unimplemented 4 LISTEN 1 3 BORM 0 2 WUPM 0 1 SLPAK 0 0 INITAK 1 Figure 11-5. MSCAN Control Register 1 (CANCTL1) Read: Anytime Write: Anytime when INITRQ = 1 and INITAK = 1, except CANE which is write once in normal and anytime in special system operation modes when the MSCAN is in initialization mode (INITRQ = 1 and INITAK = 1). Table 11-3. CANCTL1 Register Field Descriptions Field Description 7 CANE 6 CLKSRC 5 LOOPB 4 LISTEN 3 BORM 2 WUPM MSCAN Enable 0 MSCAN module is disabled 1 MSCAN module is enabled MSCAN Clock Source — This bit defines the clock source for the MSCAN module (only for systems with a clock generation module; Section 11.4.3.2, “Clock System,” and Section Figure 11-43., “MSCAN Clocking Scheme,”). 0 MSCAN clock source is the oscillator clock 1 MSCAN clock source is the bus clock Loopback Self Test Mode — When this bit is set, the MSCAN performs an internal loopback which can be used for self test operation. The bit stream output of the transmitter is fed back to the receiver internally. The RXCAN input pin is ignored and the TXCAN output goes to the recessive state (logic 1). The MSCAN behaves as it does normally when transmitting and treats its own transmitted message as a message received from a remote node. In this state, the MSCAN ignores the bit sent during the ACK slot in the CAN frame acknowledge field to ensure proper reception of its own message. Both transmit and receive interrupts are generated. 0 Loopback self test disabled 1 Loopback self test enabled Listen Only Mode — This bit configures the MSCAN as a CAN bus monitor. When LISTEN is set, all valid CAN messages with matching ID are received, but no acknowledgement or error frames are sent out (see Section 11.4.4.4, “Listen-Only Mode”). In addition, the error counters are frozen. Listen only mode supports applications which require “hot plugging” or throughput analysis. The MSCAN is unable to transmit any messages when listen only mode is active. 0 Normal operation 1 Listen only mode activated Bus-Off Recovery Mode — This bits configures the bus-off state recovery mode of the MSCAN. Refer to Section 11.5.2, “Bus-Off Recovery,” for details. 0 Automatic bus-off recovery (see Bosch CAN 2.0A/B protocol specification) 1 Bus-off recovery upon user request Wake-Up Mode — If WUPE in CANCTL0 is enabled, this bit defines whether the integrated low-pass filter is applied to protect the MSCAN from spurious wake-up (see Section 11.4.5.4, “MSCAN Sleep Mode”). 0 MSCAN wakes up on any dominant level on the CAN bus 1 MSCAN wakes up only in case of a dominant pulse on the CAN bus that has a length of Twup S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 301 Freescale’s Scalable Controller Area Network (S12MSCANV3) Table 11-3. CANCTL1 Register Field Descriptions (continued) Field 1 SLPAK 0 INITAK Description Sleep Mode Acknowledge — This flag indicates whether the MSCAN module has entered sleep mode (see Section 11.4.5.4, “MSCAN Sleep Mode”). It is used as a handshake flag for the SLPRQ sleep mode request. Sleep mode is active when SLPRQ = 1 and SLPAK = 1. Depending on the setting of WUPE, the MSCAN will clear the flag if it detects activity on the CAN bus while in sleep mode. 0 Running — The MSCAN operates normally 1 Sleep mode active — The MSCAN has entered sleep mode Initialization Mode Acknowledge — This flag indicates whether the MSCAN module is in initialization mode (see Section 11.4.5.5, “MSCAN Initialization Mode”). It is used as a handshake flag for the INITRQ initialization mode request. Initialization mode is active when INITRQ = 1 and INITAK = 1. The registers CANCTL1, CANBTR0, CANBTR1, CANIDAC, CANIDAR0–CANIDAR7, and CANIDMR0–CANIDMR7 can be written only by the CPU when the MSCAN is in initialization mode. 0 Running — The MSCAN operates normally 1 Initialization mode active — The MSCAN has entered initialization mode 11.3.2.3 MSCAN Bus Timing Register 0 (CANBTR0) The CANBTR0 register configures various CAN bus timing parameters of the MSCAN module. Module Base + 0x0002 7 R SJW1 W 6 SJW0 5 BRP5 4 BRP4 3 BRP3 2 BRP2 Reset: 0 0 0 0 0 0 Figure 11-6. MSCAN Bus Timing Register 0 (CANBTR0) Read: Anytime Write: Anytime in initialization mode (INITRQ = 1 and INITAK = 1) 1 BRP1 0 0 BRP0 0 Table 11-4. CANBTR0 Register Field Descriptions Field Description 7:6 SJW[1:0] 5:0 BRP[5:0] Synchronization Jump Width — The synchronization jump width defines the maximum number of time quanta (Tq) clock cycles a bit can be shortened or lengthened to achieve resynchronization to data transitions on the CAN bus (see Table 11-5). Baud Rate Prescaler — These bits determine the time quanta (Tq) clock which is used to build up the bit timing (see Table 11-6). Table 11-5. Synchronization Jump Width SJW1 0 0 1 SJW0 0 1 0 Synchronization Jump Width 1 Tq clock cycle 2 Tq clock cycles 3 Tq clock cycles S12XS-Family Reference Manual, Rev. 1.03 302 PRELIMINARY Freescale Semiconductor Freescale’s Scalable Controller Area Network (S12MSCANV3) Table 11-5. Synchronization Jump Width (continued) SJW1 1 SJW0 1 Synchronization Jump Width 4 Tq clock cycles Table 11-6. Baud Rate Prescaler BRP5 0 0 0 0 : 1 BRP4 0 0 0 0 : 1 BRP3 0 0 0 0 : 1 BRP2 0 0 0 0 : 1 BRP1 0 0 1 1 : 1 BRP0 0 1 0 1 : 1 Prescaler value (P) 1 2 3 4 : 64 11.3.2.4 MSCAN Bus Timing Register 1 (CANBTR1) The CANBTR1 register configures various CAN bus timing parameters of the MSCAN module. Module Base + 0x0003 7 R SAMP W 6 TSEG22 5 TSEG21 4 TSEG20 3 TSEG13 2 TSEG12 Reset: 0 0 0 0 0 0 Figure 11-7. MSCAN Bus Timing Register 1 (CANBTR1) Read: Anytime Write: Anytime in initialization mode (INITRQ = 1 and INITAK = 1) 1 TSEG11 0 0 TSEG10 0 Table 11-7. CANBTR1 Register Field Descriptions Field Description 7 SAMP Sampling — This bit determines the number of CAN bus samples taken per bit time. 0 One sample per bit. 1 Three samples per bit1. If SAMP = 0, the resulting bit value is equal to the value of the single bit positioned at the sample point. If SAMP = 1, the resulting bit value is determined by using majority rule on the three total samples. For higher bit rates, it is recommended that only one sample is taken per bit time (SAMP = 0). 6:4 Time Segment 2 — Time segments within the bit time fix the number of clock cycles per bit time and the location TSEG2[2:0] of the sample point (see Figure 11-44). Time segment 2 (TSEG2) values are programmable as shown in Table 11-8. 3:0 Time Segment 1 — Time segments within the bit time fix the number of clock cycles per bit time and the location TSEG1[3:0] of the sample point (see Figure 11-44). Time segment 1 (TSEG1) values are programmable as shown in Table 11-9. 1 In this case, PHASE_SEG1 must be at least 2 time quanta (Tq). S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 303 Freescale’s Scalable Controller Area Network (S12MSCANV3) Table 11-8. Time Segment 2 Values TSEG22 TSEG21 TSEG20 Time Segment 2 0 0 0 1 Tq clock cycle1 0 0 1 2 Tq clock cycles : : : : 1 1 0 7 Tq clock cycles 1 1 1 8 Tq clock cycles 1 This setting is not valid. Please refer to Table 11-36 for valid settings. Table 11-9. Time Segment 1 Values TSEG13 TSEG12 TSEG11 TSEG10 Time segment 1 0 0 0 0 1 Tq clock cycle1 0 0 0 1 2 Tq clock cycles1 0 0 1 0 3 Tq clock cycles1 0 0 1 1 4 Tq clock cycles : : : : : 1 1 1 0 15 Tq clock cycles 1 1 1 1 16 Tq clock cycles 1 This setting is not valid. Please refer to Table 11-36 for valid settings. The bit time is determined by the oscillator frequency, the baud rate prescaler, and the number of time quanta (Tq) clock cycles per bit (as shown in Table 11-8 and Table 11-9). Eqn. 11-1 Bit Time= (---P----r---e---f-s-C--c---A-a----Nl--e--C-r----L--v--K-a----l--u----e----) • (1 + TimeSegment1 + TimeSegment2) 11.3.2.5 MSCAN Receiver Flag Register (CANRFLG) A flag can be cleared only by software (writing a 1 to the corresponding bit position) when the condition which caused the setting is no longer valid. Every flag has an associated interrupt enable bit in the CANRIER register. Module Base + 0x0004 7 R WUPIF W 6 CSCIF 5 RSTAT1 4 RSTAT0 3 TSTAT1 2 TSTAT0 1 OVRIF 0 RXF Reset: 0 0 0 0 0 0 0 0 = Unimplemented Figure 11-8. MSCAN Receiver Flag Register (CANRFLG) S12XS-Family Reference Manual, Rev. 1.03 304 PRELIMINARY Freescale Semiconductor Freescale’s Scalable Controller Area Network (S12MSCANV3) NOTE The CANRFLG register is held in the reset state1 when the initialization mode is active (INITRQ = 1 and INITAK = 1). This register is writable again as soon as the initialization mode is exited (INITRQ = 0 and INITAK = 0). Read: Anytime Write: Anytime when out of initialization mode, except RSTAT[1:0] and TSTAT[1:0] flags which are readonly; write of 1 clears flag; write of 0 is ignored. Table 11-10. CANRFLG Register Field Descriptions Field Description 7 WUPIF Wake-Up Interrupt Flag — If the MSCAN detects CAN bus activity while in sleep mode (see Section 11.4.5.4, “MSCAN Sleep Mode,”) and WUPE = 1 in CANTCTL0 (see Section 11.3.2.1, “MSCAN Control Register 0 (CANCTL0)”), the module will set WUPIF. If not masked, a wake-up interrupt is pending while this flag is set. 0 No wake-up activity observed while in sleep mode 1 MSCAN detected activity on the CAN bus and requested wake-up 6 CSCIF CAN Status Change Interrupt Flag — This flag is set when the MSCAN changes its current CAN bus status due to the actual value of the transmit error counter (TEC) and the receive error counter (REC). An additional 4bit (RSTAT[1:0], TSTAT[1:0]) status register, which is split into separate sections for TEC/REC, informs the system on the actual CAN bus status (see Section 11.3.2.6, “MSCAN Receiver Interrupt Enable Register (CANRIER)”). If not masked, an error interrupt is pending while this flag is set. CSCIF provides a blocking interrupt. That guarantees that the receiver/transmitter status bits (RSTAT/TSTAT) are only updated when no CAN status change interrupt is pending. If the TECs/RECs change their current value after the CSCIF is asserted, which would cause an additional state change in the RSTAT/TSTAT bits, these bits keep their status until the current CSCIF interrupt is cleared again. 0 No change in CAN bus status occurred since last interrupt 1 MSCAN changed current CAN bus status 5:4 RSTAT[1:0] Receiver Status Bits — The values of the error counters control the actual CAN bus status of the MSCAN. As soon as the status change interrupt flag (CSCIF) is set, these bits indicate the appropriate receiver related CAN bus status of the MSCAN. The coding for the bits RSTAT1, RSTAT0 is: 00 RxOK: 0 ≤ receive error counter ≤ 96 01 RxWRN: 96 < receive error counter ≤ 127 10 RxERR: 127 < receive error counter 11 Bus-off1: transmit error counter > 255 3:2 TSTAT[1:0] Transmitter Status Bits — The values of the error counters control the actual CAN bus status of the MSCAN. As soon as the status change interrupt flag (CSCIF) is set, these bits indicate the appropriate transmitter related CAN bus status of the MSCAN. The coding for the bits TSTAT1, TSTAT0 is: 00 TxOK: 0 ≤ transmit error counter ≤ 96 01 TxWRN: 96 < transmit error counter ≤ 127 10 TxERR: 127 < transmit error counter ≤ 255 11 Bus-Off: transmit error counter > 255 1. The RSTAT[1:0], TSTAT[1:0] bits are not affected by initialization mode. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 305 Freescale’s Scalable Controller Area Network (S12MSCANV3) Table 11-10. CANRFLG Register Field Descriptions (continued) Field Description 1 OVRIF Overrun Interrupt Flag — This flag is set when a data overrun condition occurs. If not masked, an error interrupt is pending while this flag is set. 0 No data overrun condition 1 A data overrun detected 0 RXF2 Receive Buffer Full Flag — RXF is set by the MSCAN when a new message is shifted in the receiver FIFO. This flag indicates whether the shifted buffer is loaded with a correctly received message (matching identifier, matching cyclic redundancy code (CRC) and no other errors detected). After the CPU has read that message from the RxFG buffer in the receiver FIFO, the RXF flag must be cleared to release the buffer. A set RXF flag prohibits the shifting of the next FIFO entry into the foreground buffer (RxFG). If not masked, a receive interrupt is pending while this flag is set. 0 No new message available within the RxFG 1 The receiver FIFO is not empty. A new message is available in the RxFG 1 Redundant Information for the most critical CAN bus status which is “bus-off”. This only occurs if the Tx error counter exceeds a number of 255 errors. Bus-off affects the receiver state. As soon as the transmitter leaves its bus-off state the receiver state skips to RxOK too. Refer also to TSTAT[1:0] coding in this register. 2 To ensure data integrity, do not read the receive buffer registers while the RXF flag is cleared. For MCUs with dual CPUs, reading the receive buffer registers while the RXF flag is cleared may result in a CPU fault condition. 11.3.2.6 MSCAN Receiver Interrupt Enable Register (CANRIER) This register contains the interrupt enable bits for the interrupt flags described in the CANRFLG register. Module Base + 0x0005 R W Reset: 7 WUPIE 6 CSCIE 5 4 3 2 RSTATE1 RSTATE0 TSTATE1 TSTATE0 1 OVRIE 0 0 0 0 0 0 0 Figure 11-9. MSCAN Receiver Interrupt Enable Register (CANRIER) 0 RXFIE 0 NOTE The CANRIER register is held in the reset state when the initialization mode is active (INITRQ=1 and INITAK=1). This register is writable when not in initialization mode (INITRQ=0 and INITAK=0). The RSTATE[1:0], TSTATE[1:0] bits are not affected by initialization mode. Read: Anytime Write: Anytime when not in initialization mode S12XS-Family Reference Manual, Rev. 1.03 306 PRELIMINARY Freescale Semiconductor Freescale’s Scalable Controller Area Network (S12MSCANV3) Table 11-11. CANRIER Register Field Descriptions Field Description 7 WUPIE1 Wake-Up Interrupt Enable 0 No interrupt request is generated from this event. 1 A wake-up event causes a Wake-Up interrupt request. 6 CSCIE CAN Status Change Interrupt Enable 0 No interrupt request is generated from this event. 1 A CAN Status Change event causes an error interrupt request. 5:4 Receiver Status Change Enable — These RSTAT enable bits control the sensitivity level in which receiver state RSTATE[1:0] changes are causing CSCIF interrupts. Independent of the chosen sensitivity level the RSTAT flags continue to indicate the actual receiver state and are only updated if no CSCIF interrupt is pending. 00 Do not generate any CSCIF interrupt caused by receiver state changes. 01 Generate CSCIF interrupt only if the receiver enters or leaves “bus-off” state. Discard other receiver state changes for generating CSCIF interrupt. 10 Generate CSCIF interrupt only if the receiver enters or leaves “RxErr” or “bus-off”2 state. Discard other receiver state changes for generating CSCIF interrupt. 11 Generate CSCIF interrupt on all state changes. 3:2 Transmitter Status Change Enable — These TSTAT enable bits control the sensitivity level in which transmitter TSTATE[1:0] state changes are causing CSCIF interrupts. Independent of the chosen sensitivity level, the TSTAT flags continue to indicate the actual transmitter state and are only updated if no CSCIF interrupt is pending. 00 Do not generate any CSCIF interrupt caused by transmitter state changes. 01 Generate CSCIF interrupt only if the transmitter enters or leaves “bus-off” state. Discard other transmitter state changes for generating CSCIF interrupt. 10 Generate CSCIF interrupt only if the transmitter enters or leaves “TxErr” or “bus-off” state. Discard other transmitter state changes for generating CSCIF interrupt. 11 Generate CSCIF interrupt on all state changes. 1 OVRIE Overrun Interrupt Enable 0 No interrupt request is generated from this event. 1 An overrun event causes an error interrupt request. 0 RXFIE Receiver Full Interrupt Enable 0 No interrupt request is generated from this event. 1 A receive buffer full (successful message reception) event causes a receiver interrupt request. 1 WUPIE and WUPE (see Section 11.3.2.1, “MSCAN Control Register 0 (CANCTL0)”) must both be enabled if the recovery mechanism from stop or wait is required. 2 Bus-off state is defined by the CAN standard (see Bosch CAN 2.0A/B protocol specification: for only transmitters. Because the only possible state change for the transmitter from bus-off to TxOK also forces the receiver to skip its current state to RxOK, the coding of the RXSTAT[1:0] flags define an additional bus-off state for the receiver (see Section 11.3.2.5, “MSCAN Receiver Flag Register (CANRFLG)”). 11.3.2.7 MSCAN Transmitter Flag Register (CANTFLG) The transmit buffer empty flags each have an associated interrupt enable bit in the CANTIER register. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 307 Freescale’s Scalable Controller Area Network (S12MSCANV3) Module Base + 0x0006 R W Reset: 7 6 5 4 3 2 1 0 0 0 0 0 TXE2 TXE1 0 0 0 0 0 1 1 = Unimplemented Figure 11-10. MSCAN Transmitter Flag Register (CANTFLG) NOTE The CANTFLG register is held in the reset state when the initialization mode is active (INITRQ = 1 and INITAK = 1). This register is writable when not in initialization mode (INITRQ = 0 and INITAK = 0). 0 TXE0 1 Read: Anytime Write: Anytime for TXEx flags when not in initialization mode; write of 1 clears flag, write of 0 is ignored Table 11-12. CANTFLG Register Field Descriptions Field Description 2:0 TXE[2:0] Transmitter Buffer Empty — This flag indicates that the associated transmit message buffer is empty, and thus not scheduled for transmission. The CPU must clear the flag after a message is set up in the transmit buffer and is due for transmission. The MSCAN sets the flag after the message is sent successfully. The flag is also set by the MSCAN when the transmission request is successfully aborted due to a pending abort request (see Section 11.3.2.9, “MSCAN Transmitter Message Abort Request Register (CANTARQ)”). If not masked, a transmit interrupt is pending while this flag is set. Clearing a TXEx flag also clears the corresponding ABTAKx (see Section 11.3.2.10, “MSCAN Transmitter Message Abort Acknowledge Register (CANTAAK)”). When a TXEx flag is set, the corresponding ABTRQx bit is cleared (see Section 11.3.2.9, “MSCAN Transmitter Message Abort Request Register (CANTARQ)”). When listen-mode is active (see Section 11.3.2.2, “MSCAN Control Register 1 (CANCTL1)”) the TXEx flags cannot be cleared and no transmission is started. Read and write accesses to the transmit buffer will be blocked, if the corresponding TXEx bit is cleared (TXEx = 0) and the buffer is scheduled for transmission. 0 The associated message buffer is full (loaded with a message due for transmission) 1 The associated message buffer is empty (not scheduled) 11.3.2.8 MSCAN Transmitter Interrupt Enable Register (CANTIER) This register contains the interrupt enable bits for the transmit buffer empty interrupt flags. S12XS-Family Reference Manual, Rev. 1.03 308 PRELIMINARY Freescale Semiconductor Freescale’s Scalable Controller Area Network (S12MSCANV3) Module Base + 0x0007 R W Reset: 7 6 5 4 3 2 1 0 0 0 0 0 TXEIE2 TXEIE1 0 0 0 0 0 0 0 = Unimplemented Figure 11-11. MSCAN Transmitter Interrupt Enable Register (CANTIER) NOTE The CANTIER register is held in the reset state when the initialization mode is active (INITRQ = 1 and INITAK = 1). This register is writable when not in initialization mode (INITRQ = 0 and INITAK = 0). Read: Anytime Write: Anytime when not in initialization mode 0 TXEIE0 0 Table 11-13. CANTIER Register Field Descriptions Field Description 2:0 TXEIE[2:0] Transmitter Empty Interrupt Enable 0 No interrupt request is generated from this event. 1 A transmitter empty (transmit buffer available for transmission) event causes a transmitter empty interrupt request. 11.3.2.9 MSCAN Transmitter Message Abort Request Register (CANTARQ) The CANTARQ register allows abort request of queued messages as described below. Module Base + 0x0008 7 6 5 4 3 2 1 R 0 0 0 0 0 ABTRQ2 ABTRQ1 W Reset: 0 0 0 0 0 0 0 = Unimplemented Figure 11-12. MSCAN Transmitter Message Abort Request Register (CANTARQ) NOTE The CANTARQ register is held in the reset state when the initialization mode is active (INITRQ = 1 and INITAK = 1). This register is writable when not in initialization mode (INITRQ = 0 and INITAK = 0). Read: Anytime Write: Anytime when not in initialization mode 0 ABTRQ0 0 S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 309 Freescale’s Scalable Controller Area Network (S12MSCANV3) Table 11-14. CANTARQ Register Field Descriptions Field Description 2:0 Abort Request — The CPU sets the ABTRQx bit to request that a scheduled message buffer (TXEx = 0) be ABTRQ[2:0] aborted. The MSCAN grants the request if the message has not already started transmission, or if the transmission is not successful (lost arbitration or error). When a message is aborted, the associated TXE (see Section 11.3.2.7, “MSCAN Transmitter Flag Register (CANTFLG)”) and abort acknowledge flags (ABTAK, see Section 11.3.2.10, “MSCAN Transmitter Message Abort Acknowledge Register (CANTAAK)”) are set and a transmit interrupt occurs if enabled. The CPU cannot reset ABTRQx. ABTRQx is reset whenever the associated TXE flag is set. 0 No abort request 1 Abort request pending 11.3.2.10 MSCAN Transmitter Message Abort Acknowledge Register (CANTAAK) The CANTAAK register indicates the successful abort of a queued message, if requested by the appropriate bits in the CANTARQ register. Module Base + 0x0009 7 6 5 4 3 2 1 0 R 0 0 0 0 0 ABTAK2 ABTAK1 ABTAK0 W Reset: 0 0 0 0 0 0 0 0 = Unimplemented Figure 11-13. MSCAN Transmitter Message Abort Acknowledge Register (CANTAAK) NOTE The CANTAAK register is held in the reset state when the initialization mode is active (INITRQ = 1 and INITAK = 1). Read: Anytime Write: Unimplemented for ABTAKx flags Table 11-15. CANTAAK Register Field Descriptions Field Description 2:0 ABTAK[2:0] Abort Acknowledge — This flag acknowledges that a message was aborted due to a pending abort request from the CPU. After a particular message buffer is flagged empty, this flag can be used by the application software to identify whether the message was aborted successfully or was sent anyway. The ABTAKx flag is cleared whenever the corresponding TXE flag is cleared. 0 The message was not aborted. 1 The message was aborted. S12XS-Family Reference Manual, Rev. 1.03 310 PRELIMINARY Freescale Semiconductor Freescale’s Scalable Controller Area Network (S12MSCANV3) 11.3.2.11 MSCAN Transmit Buffer Selection Register (CANTBSEL) The CANTBSEL register allows the selection of the actual transmit message buffer, which then will be accessible in the CANTXFG register space. Module Base + 0x000A 7 6 5 4 3 2 1 0 R 0 0 0 0 0 TX2 TX1 TX0 W Reset: 0 0 0 0 0 0 0 0 = Unimplemented Figure 11-14. MSCAN Transmit Buffer Selection Register (CANTBSEL) NOTE The CANTBSEL register is held in the reset state when the initialization mode is active (INITRQ = 1 and INITAK=1). This register is writable when not in initialization mode (INITRQ = 0 and INITAK = 0). Read: Find the lowest ordered bit set to 1, all other bits will be read as 0 Write: Anytime when not in initialization mode Table 11-16. CANTBSEL Register Field Descriptions Field 2:0 TX[2:0] Description Transmit Buffer Select — The lowest numbered bit places the respective transmit buffer in the CANTXFG register space (e.g., TX1 = 1 and TX0 = 1 selects transmit buffer TX0; TX1 = 1 and TX0 = 0 selects transmit buffer TX1). Read and write accesses to the selected transmit buffer will be blocked, if the corresponding TXEx bit is cleared and the buffer is scheduled for transmission (see Section 11.3.2.7, “MSCAN Transmitter Flag Register (CANTFLG)”). 0 The associated message buffer is deselected 1 The associated message buffer is selected, if lowest numbered bit The following gives a short programming example of the usage of the CANTBSEL register: To get the next available transmit buffer, application software must read the CANTFLG register and write this value back into the CANTBSEL register. In this example Tx buffers TX1 and TX2 are available. The value read from CANTFLG is therefore 0b0000_0110. When writing this value back to CANTBSEL, the Tx buffer TX1 is selected in the CANTXFG because the lowest numbered bit set to 1 is at bit position 1. Reading back this value out of CANTBSEL results in 0b0000_0010, because only the lowest numbered bit position set to 1 is presented. This mechanism eases the application software the selection of the next available Tx buffer. • LDAA CANTFLG; value read is 0b0000_0110 • STAA CANTBSEL; value written is 0b0000_0110 • LDAA CANTBSEL; value read is 0b0000_0010 S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 311 Freescale’s Scalable Controller Area Network (S12MSCANV3) If all transmit message buffers are deselected, no accesses are allowed to the CANTXFG registers. 11.3.2.12 MSCAN Identifier Acceptance Control Register (CANIDAC) The CANIDAC register is used for identifier acceptance control as described below. Module Base + 0x000B 7 R 0 W 6 5 4 3 2 1 0 0 0 IDHIT2 IDHIT1 IDHIT0 IDAM1 IDAM0 Reset: 0 0 0 0 0 0 0 0 = Unimplemented Figure 11-15. MSCAN Identifier Acceptance Control Register (CANIDAC) Read: Anytime Write: Anytime in initialization mode (INITRQ = 1 and INITAK = 1), except bits IDHITx, which are readonly Table 11-17. CANIDAC Register Field Descriptions Field Description 5:4 Identifier Acceptance Mode — The CPU sets these flags to define the identifier acceptance filter organization IDAM[1:0] (see Section 11.4.3, “Identifier Acceptance Filter”). Table 11-18 summarizes the different settings. In filter closed mode, no message is accepted such that the foreground buffer is never reloaded. 2:0 Identifier Acceptance Hit Indicator — The MSCAN sets these flags to indicate an identifier acceptance hit (see IDHIT[2:0] Section 11.4.3, “Identifier Acceptance Filter”). Table 11-19 summarizes the different settings. IDAM1 0 0 1 1 Table 11-18. Identifier Acceptance Mode Settings IDAM0 0 1 0 1 Identifier Acceptance Mode Two 32-bit acceptance filters Four 16-bit acceptance filters Eight 8-bit acceptance filters Filter closed S12XS-Family Reference Manual, Rev. 1.03 312 PRELIMINARY Freescale Semiconductor Freescale’s Scalable Controller Area Network (S12MSCANV3) Table 11-19. Identifier Acceptance Hit Indication IDHIT2 0 0 0 0 1 1 1 1 IDHIT1 0 0 1 1 0 0 1 1 IDHIT0 0 1 0 1 0 1 0 1 Identifier Acceptance Hit Filter 0 hit Filter 1 hit Filter 2 hit Filter 3 hit Filter 4 hit Filter 5 hit Filter 6 hit Filter 7 hit The IDHITx indicators are always related to the message in the foreground buffer (RxFG). When a message gets shifted into the foreground buffer of the receiver FIFO the indicators are updated as well. 11.3.2.13 MSCAN Reserved Register This register is reserved for factory testing of the MSCAN module and is not available in normal system operation modes. Module Base + 0x000C 7 6 5 4 3 2 1 0 R 0 0 0 0 0 0 0 0 W Reset: 0 0 0 0 0 0 0 0 = Unimplemented Figure 11-16. MSCAN Reserved Register Read: Always read 0x0000 in normal system operation modes Write: Unimplemented in normal system operation modes NOTE Writing to this register when in special modes can alter the MSCAN functionality. 11.3.2.14 MSCAN Miscellaneous Register (CANMISC) This register provides additional features. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 313 Freescale’s Scalable Controller Area Network (S12MSCANV3) Module Base + 0x000D 7 6 5 4 3 2 1 R 0 0 0 0 0 0 0 W Reset: 0 0 0 0 0 0 0 = Unimplemented Figure 11-17. MSCAN Miscellaneous Register (CANMISC) Read: Anytime Write: Anytime; write of ‘1’ clears flag; write of ‘0’ ignored 0 BOHOLD 0 Table 11-20. CANMISC Register Field Descriptions Field Description 0 BOHOLD Bus-off State Hold Until User Request — If BORM is set in Section 11.3.2.2, “MSCAN Control Register 1 (CANCTL1), this bit indicates whether the module has entered the bus-off state. Clearing this bit requests the recovery from bus-off. Refer to Section 11.5.2, “Bus-Off Recovery,” for details. 0 Module is not bus-off or recovery has been requested by user in bus-off state 1 Module is bus-off and holds this state until user request 11.3.2.15 MSCAN Receive Error Counter (CANRXERR) This register reflects the status of the MSCAN receive error counter. Module Base + 0x000E 7 R RXERR7 6 RXERR6 5 RXERR5 4 RXERR4 3 RXERR3 2 RXERR2 1 RXERR1 0 RXERR0 W Reset: 0 0 0 0 0 0 0 0 = Unimplemented Figure 11-18. MSCAN Receive Error Counter (CANRXERR) Read: Only when in sleep mode (SLPRQ = 1 and SLPAK = 1) or initialization mode (INITRQ = 1 and INITAK = 1) Write: Unimplemented NOTE Reading this register when in any other mode other than sleep or initialization mode may return an incorrect value. For MCUs with dual CPUs, this may result in a CPU fault condition. S12XS-Family Reference Manual, Rev. 1.03 314 PRELIMINARY Freescale Semiconductor Freescale’s Scalable Controller Area Network (S12MSCANV3) Writing to this register when in special modes can alter the MSCAN functionality. 11.3.2.16 MSCAN Transmit Error Counter (CANTXERR) This register reflects the status of the MSCAN transmit error counter. Module Base + 0x000F 7 R TXERR7 6 TXERR6 5 TXERR5 4 TXERR4 3 TXERR3 2 TXERR2 1 TXERR1 0 TXERR0 W Reset: 0 0 0 0 0 0 0 0 = Unimplemented Figure 11-19. MSCAN Transmit Error Counter (CANTXERR) Read: Only when in sleep mode (SLPRQ = 1 and SLPAK = 1) or initialization mode (INITRQ = 1 and INITAK = 1) Write: Unimplemented NOTE Reading this register when in any other mode other than sleep or initialization mode, may return an incorrect value. For MCUs with dual CPUs, this may result in a CPU fault condition. Writing to this register when in special modes can alter the MSCAN functionality. 11.3.2.17 MSCAN Identifier Acceptance Registers (CANIDAR0-7) On reception, each message is written into the background receive buffer. The CPU is only signalled to read the message if it passes the criteria in the identifier acceptance and identifier mask registers (accepted); otherwise, the message is overwritten by the next message (dropped). The acceptance registers of the MSCAN are applied on the IDR0–IDR3 registers (see Section 11.3.3.1, “Identifier Registers (IDR0–IDR3)”) of incoming messages in a bit by bit manner (see Section 11.4.3, “Identifier Acceptance Filter”). For extended identifiers, all four acceptance and mask registers are applied. For standard identifiers, only the first two (CANIDAR0/1, CANIDMR0/1) are applied. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 315 Freescale’s Scalable Controller Area Network (S12MSCANV3) Module Base + 0x0010 (CANIDAR0) 0x0011 (CANIDAR1) 0x0012 (CANIDAR2) 0x0013 (CANIDAR3) 7 R AC7 W 6 AC6 5 AC5 4 AC4 3 AC3 2 AC2 1 AC1 0 AC0 Reset 0 0 0 0 0 0 0 0 7 R AC7 W 6 AC6 5 AC5 4 AC4 3 AC3 2 AC2 1 AC1 0 AC0 Reset 0 0 0 0 0 0 0 0 7 R AC7 W 6 AC6 5 AC5 4 AC4 3 AC3 2 AC2 1 AC1 0 AC0 Reset 0 0 0 0 0 0 0 0 7 R AC7 W 6 AC6 5 AC5 4 AC4 3 AC3 2 AC2 1 AC1 0 AC0 Reset 0 0 0 0 0 0 0 0 Figure 11-20. MSCAN Identifier Acceptance Registers (First Bank) — CANIDAR0–CANIDAR3 Read: Anytime Write: Anytime in initialization mode (INITRQ = 1 and INITAK = 1) Table 11-21. CANIDAR0–CANIDAR3 Register Field Descriptions Field 7:0 AC[7:0] Description Acceptance Code Bits — AC[7:0] comprise a user-defined sequence of bits with which the corresponding bits of the related identifier register (IDRn) of the receive message buffer are compared. The result of this comparison is then masked with the corresponding identifier mask register. S12XS-Family Reference Manual, Rev. 1.03 316 PRELIMINARY Freescale Semiconductor Freescale’s Scalable Controller Area Network (S12MSCANV3) Module Base + 0x0018 (CANIDAR4) 0x0019 (CANIDAR5) 0x001A (CANIDAR6) 0x001B (CANIDAR7) 7 R AC7 W Reset 0 6 AC6 0 5 AC5 0 4 AC4 0 3 AC3 0 2 AC2 0 1 AC1 0 0 AC0 0 7 R AC7 W Reset 0 6 AC6 0 5 AC5 0 4 AC4 0 3 AC3 0 2 AC2 0 1 AC1 0 0 AC0 0 7 R AC7 W Reset 0 6 AC6 0 5 AC5 0 4 AC4 0 3 AC3 0 2 AC2 0 1 AC1 0 0 AC0 0 7 R AC7 W Reset 0 6 AC6 0 5 AC5 0 4 AC4 0 3 AC3 0 2 AC2 0 1 AC1 0 0 AC0 0 Figure 11-21. MSCAN Identifier Acceptance Registers (Second Bank) — CANIDAR4–CANIDAR7 Read: Anytime Write: Anytime in initialization mode (INITRQ = 1 and INITAK = 1) Table 11-22. CANIDAR4–CANIDAR7 Register Field Descriptions Field 7:0 AC[7:0] Description Acceptance Code Bits — AC[7:0] comprise a user-defined sequence of bits with which the corresponding bits of the related identifier register (IDRn) of the receive message buffer are compared. The result of this comparison is then masked with the corresponding identifier mask register. 11.3.2.18 MSCAN Identifier Mask Registers (CANIDMR0–CANIDMR7) The identifier mask register specifies which of the corresponding bits in the identifier acceptance register are relevant for acceptance filtering. To receive standard identifiers in 32 bit filter mode, it is required to program the last three bits (AM[2:0]) in the mask registers CANIDMR1 and CANIDMR5 to “don’t care.” S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 317 Freescale’s Scalable Controller Area Network (S12MSCANV3) To receive standard identifiers in 16 bit filter mode, it is required to program the last three bits (AM[2:0]) in the mask registers CANIDMR1, CANIDMR3, CANIDMR5, and CANIDMR7 to “don’t care.” Module Base + 0x0014 (CANIDMR0) 0x0015 (CANIDMR1) 0x0016 (CANIDMR2) 0x0017 (CANIDMR3) R W Reset 7 AM7 0 6 AM6 0 R W Reset 7 AM7 0 6 AM6 0 R W Reset 7 AM7 0 6 AM6 0 R W Reset 7 AM7 0 6 AM6 0 5 AM5 0 5 AM5 0 5 AM5 0 5 AM5 0 4 AM4 0 4 AM4 0 4 AM4 0 4 AM4 0 3 AM3 0 3 AM3 0 3 AM3 0 3 AM3 0 2 AM2 0 2 AM2 0 2 AM2 0 2 AM2 0 1 AM1 0 1 AM1 0 1 AM1 0 1 AM1 0 0 AM0 0 0 AM0 0 0 AM0 0 0 AM0 0 Figure 11-22. MSCAN Identifier Mask Registers (First Bank) — CANIDMR0–CANIDMR3 Read: Anytime Write: Anytime in initialization mode (INITRQ = 1 and INITAK = 1) Table 11-23. CANIDMR0–CANIDMR3 Register Field Descriptions Field 7:0 AM[7:0] Description Acceptance Mask Bits — If a particular bit in this register is cleared, this indicates that the corresponding bit in the identifier acceptance register must be the same as its identifier bit before a match is detected. The message is accepted if all such bits match. If a bit is set, it indicates that the state of the corresponding bit in the identifier acceptance register does not affect whether or not the message is accepted. 0 Match corresponding acceptance code register and identifier bits 1 Ignore corresponding acceptance code register bit S12XS-Family Reference Manual, Rev. 1.03 318 PRELIMINARY Freescale Semiconductor Freescale’s Scalable Controller Area Network (S12MSCANV3) Module Base + 0x001C (CANIDMR4) 0x001D (CANIDMR5) 0x001E (CANIDMR6) 0x001F (CANIDMR7) R W Reset 7 AM7 0 6 AM6 0 R W Reset 7 AM7 0 6 AM6 0 R W Reset 7 AM7 0 6 AM6 0 R W Reset 7 AM7 0 6 AM6 0 5 AM5 0 5 AM5 0 5 AM5 0 5 AM5 0 4 AM4 0 4 AM4 0 4 AM4 0 4 AM4 0 3 AM3 0 3 AM3 0 3 AM3 0 3 AM3 0 2 AM2 0 2 AM2 0 2 AM2 0 2 AM2 0 1 AM1 0 1 AM1 0 1 AM1 0 1 AM1 0 0 AM0 0 0 AM0 0 0 AM0 0 0 AM0 0 Figure 11-23. MSCAN Identifier Mask Registers (Second Bank) — CANIDMR4–CANIDMR7 Read: Anytime Write: Anytime in initialization mode (INITRQ = 1 and INITAK = 1) Table 11-24. CANIDMR4–CANIDMR7 Register Field Descriptions Field 7:0 AM[7:0] Description Acceptance Mask Bits — If a particular bit in this register is cleared, this indicates that the corresponding bit in the identifier acceptance register must be the same as its identifier bit before a match is detected. The message is accepted if all such bits match. If a bit is set, it indicates that the state of the corresponding bit in the identifier acceptance register does not affect whether or not the message is accepted. 0 Match corresponding acceptance code register and identifier bits 1 Ignore corresponding acceptance code register bit S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 319 Freescale’s Scalable Controller Area Network (S12MSCANV3) 11.3.3 Programmer’s Model of Message Storage The following section details the organization of the receive and transmit message buffers and the associated control registers. To simplify the programmer interface, the receive and transmit message buffers have the same outline. Each message buffer allocates 16 bytes in the memory map containing a 13 byte data structure. An additional transmit buffer priority register (TBPR) is defined for the transmit buffers. Within the last two bytes of this memory map, the MSCAN stores a special 16-bit time stamp, which is sampled from an internal timer after successful transmission or reception of a message. This feature is only available for transmit and receiver buffers, if the TIME bit is set (see Section 11.3.2.1, “MSCAN Control Register 0 (CANCTL0)”). The time stamp register is written by the MSCAN. The CPU can only read these registers. Table 11-25. Message Buffer Organization Offset Address Register Access 0x00X0 Identifier Register 0 0x00X1 Identifier Register 1 0x00X2 Identifier Register 2 0x00X3 Identifier Register 3 0x00X4 Data Segment Register 0 0x00X5 Data Segment Register 1 0x00X6 Data Segment Register 2 0x00X7 Data Segment Register 3 0x00X8 Data Segment Register 4 0x00X9 Data Segment Register 5 0x00XA Data Segment Register 6 0x00XB Data Segment Register 7 0x00XC Data Length Register 0x00XD Transmit Buffer Priority Register1 0x00XE Time Stamp Register (High Byte)2 0x00XF Time Stamp Register (Low Byte)3 1 Not applicable for receive buffers 2 Read-only for CPU 3 Read-only for CPU Figure 11-24 shows the common 13-byte data structure of receive and transmit buffers for extended identifiers. The mapping of standard identifiers into the IDR registers is shown in Figure 11-25. All bits of the receive and transmit buffers are ‘x’ out of reset because of RAM-based implementation1. All reserved or unused bits of the receive and transmit buffers always read ‘x’. 1. Exception: The transmit priority registers are 0 out of reset. S12XS-Family Reference Manual, Rev. 1.03 320 PRELIMINARY Freescale Semiconductor Freescale’s Scalable Controller Area Network (S12MSCANV3) Figure 11-24. Receive/Transmit Message Buffer — Extended Identifier Mapping Register Name 0x00X0 R IDR0 W Bit 7 ID28 6 ID27 5 ID26 4 ID25 3 ID24 2 ID23 1 ID22 Bit0 ID21 0x00X1 IDR1 R W ID20 ID19 ID18 SRR (=1) IDE (=1) ID17 ID16 ID15 0x00X2 IDR2 R W ID14 ID13 ID12 ID11 ID10 ID9 ID8 ID7 0x00X3 R IDR3 W ID6 ID5 ID4 ID3 ID2 ID1 ID0 RTR 0x00X4 DSR0 R W DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0 0x00X5 DSR1 R W DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0 0x00X6 DSR2 R W DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0 0x00X7 DSR3 R W DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0 0x00X8 DSR4 R W DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0 0x00X9 DSR5 R W DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0 0x00XA DSR6 R W DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0 0x00XB DSR7 R W DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0 0x00XC R DLR W DLC3 DLC2 DLC1 DLC0 S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 321 Freescale’s Scalable Controller Area Network (S12MSCANV3) Figure 11-24. Receive/Transmit Message Buffer — Extended Identifier Mapping (continued) Register Name Bit 7 6 5 4 3 2 1 Bit0 = Unused, always read ‘x’ Read: For transmit buffers, anytime when TXEx flag is set (see Section 11.3.2.7, “MSCAN Transmitter Flag Register (CANTFLG)”) and the corresponding transmit buffer is selected in CANTBSEL (see Section 11.3.2.11, “MSCAN Transmit Buffer Selection Register (CANTBSEL)”). For receive buffers, only when RXF flag is set (see Section 11.3.2.5, “MSCAN Receiver Flag Register (CANRFLG)”). Write: For transmit buffers, anytime when TXEx flag is set (see Section 11.3.2.7, “MSCAN Transmitter Flag Register (CANTFLG)”) and the corresponding transmit buffer is selected in CANTBSEL (see Section 11.3.2.11, “MSCAN Transmit Buffer Selection Register (CANTBSEL)”). Unimplemented for receive buffers. Reset: Undefined (0x00XX) because of RAM-based implementation Figure 11-25. Receive/Transmit Message Buffer — Standard Identifier Mapping Register Name Bit 7 6 5 4 3 2 1 IDR0 0x00X0 R W ID10 ID9 ID8 ID7 ID6 ID5 ID4 Bit 0 ID3 IDR1 R 0x00X1 W ID2 ID1 ID0 RTR IDE (=0) IDR2 R 0x00X2 W IDR3 R 0x00X3 W = Unused, always read ‘x’ 11.3.3.1 Identifier Registers (IDR0–IDR3) The identifier registers for an extended format identifier consist of a total of 32 bits; ID[28:0], SRR, IDE, and RTR bits. The identifier registers for a standard format identifier consist of a total of 13 bits; ID[10:0], RTR, and IDE bits. S12XS-Family Reference Manual, Rev. 1.03 322 PRELIMINARY Freescale Semiconductor Freescale’s Scalable Controller Area Network (S12MSCANV3) 11.3.3.1.1 IDR0–IDR3 for Extended Identifier Mapping Module Base + 0x00X1 R W Reset: 7 ID28 6 ID27 5 ID26 4 ID25 3 ID24 2 ID23 1 ID22 x x x x x x x Figure 11-26. Identifier Register 0 (IDR0) — Extended Identifier Mapping Table 11-26. IDR0 Register Field Descriptions — Extended 0 ID21 x Field Description 7:0 ID[28:21] Extended Format Identifier — The identifiers consist of 29 bits (ID[28:0]) for the extended format. ID28 is the most significant bit and is transmitted first on the CAN bus during the arbitration procedure. The priority of an identifier is defined to be highest for the smallest binary number. Module Base + 0x00X1 R W Reset: 7 ID20 6 ID19 5 ID18 4 SRR (=1) 3 IDE (=1) 2 ID17 1 ID16 x x x x x x x Figure 11-27. Identifier Register 1 (IDR1) — Extended Identifier Mapping 0 ID15 x Table 11-27. IDR1 Register Field Descriptions — Extended Field Description 7:5 ID[20:18] 4 SRR 3 IDE 2:0 ID[17:15] Extended Format Identifier — The identifiers consist of 29 bits (ID[28:0]) for the extended format. ID28 is the most significant bit and is transmitted first on the CAN bus during the arbitration procedure. The priority of an identifier is defined to be highest for the smallest binary number. Substitute Remote Request — This fixed recessive bit is used only in extended format. It must be set to 1 by the user for transmission buffers and is stored as received on the CAN bus for receive buffers. ID Extended — This flag indicates whether the extended or standard identifier format is applied in this buffer. In the case of a receive buffer, the flag is set as received and indicates to the CPU how to process the buffer identifier registers. In the case of a transmit buffer, the flag indicates to the MSCAN what type of identifier to send. 0 Standard format (11 bit) 1 Extended format (29 bit) Extended Format Identifier — The identifiers consist of 29 bits (ID[28:0]) for the extended format. ID28 is the most significant bit and is transmitted first on the CAN bus during the arbitration procedure. The priority of an identifier is defined to be highest for the smallest binary number. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 323 Freescale’s Scalable Controller Area Network (S12MSCANV3) Module Base + 0x00X2 7 6 5 4 3 2 1 0 R ID14 ID13 ID12 ID11 ID10 ID9 ID8 ID7 W Reset: x x x x x x x x Figure 11-28. Identifier Register 2 (IDR2) — Extended Identifier Mapping Table 11-28. IDR2 Register Field Descriptions — Extended Field 7:0 ID[14:7] Description Extended Format Identifier — The identifiers consist of 29 bits (ID[28:0]) for the extended format. ID28 is the most significant bit and is transmitted first on the CAN bus during the arbitration procedure. The priority of an identifier is defined to be highest for the smallest binary number. Module Base + 0x00X3 7 6 5 4 3 2 1 0 R ID6 ID5 ID4 ID3 ID2 ID1 ID0 RTR W Reset: x x x x x x x x Figure 11-29. Identifier Register 3 (IDR3) — Extended Identifier Mapping Field 7:1 ID[6:0] 0 RTR Table 11-29. IDR3 Register Field Descriptions — Extended Description Extended Format Identifier — The identifiers consist of 29 bits (ID[28:0]) for the extended format. ID28 is the most significant bit and is transmitted first on the CAN bus during the arbitration procedure. The priority of an identifier is defined to be highest for the smallest binary number. Remote Transmission Request — This flag reflects the status of the remote transmission request bit in the CAN frame. In the case of a receive buffer, it indicates the status of the received frame and supports the transmission of an answering frame in software. In the case of a transmit buffer, this flag defines the setting of the RTR bit to be sent. 0 Data frame 1 Remote frame S12XS-Family Reference Manual, Rev. 1.03 324 PRELIMINARY Freescale Semiconductor Freescale’s Scalable Controller Area Network (S12MSCANV3) 11.3.3.1.2 IDR0–IDR3 for Standard Identifier Mapping Module Base + 0x00X0 7 6 5 4 3 2 1 0 R ID10 ID9 ID8 ID7 ID6 ID5 ID4 ID3 W Reset: x x x x x x x x Figure 11-30. Identifier Register 0 — Standard Mapping Table 11-30. IDR0 Register Field Descriptions — Standard Field 7:0 ID[10:3] Description Standard Format Identifier — The identifiers consist of 11 bits (ID[10:0]) for the standard format. ID10 is the most significant bit and is transmitted first on the CAN bus during the arbitration procedure. The priority of an identifier is defined to be highest for the smallest binary number. See also ID bits in Table 11-31. Module Base + 0x00X1 7 6 5 4 3 2 1 0 R ID2 ID1 ID0 RTR IDE (=0) W Reset: x x x x x x x x = Unused; always read ‘x’ Figure 11-31. Identifier Register 1 — Standard Mapping Field 7:5 ID[2:0] 4 RTR 3 IDE Table 11-31. IDR1 Register Field Descriptions Description Standard Format Identifier — The identifiers consist of 11 bits (ID[10:0]) for the standard format. ID10 is the most significant bit and is transmitted first on the CAN bus during the arbitration procedure. The priority of an identifier is defined to be highest for the smallest binary number. See also ID bits in Table 11-30. Remote Transmission Request — This flag reflects the status of the Remote Transmission Request bit in the CAN frame. In the case of a receive buffer, it indicates the status of the received frame and supports the transmission of an answering frame in software. In the case of a transmit buffer, this flag defines the setting of the RTR bit to be sent. 0 Data frame 1 Remote frame ID Extended — This flag indicates whether the extended or standard identifier format is applied in this buffer. In the case of a receive buffer, the flag is set as received and indicates to the CPU how to process the buffer identifier registers. In the case of a transmit buffer, the flag indicates to the MSCAN what type of identifier to send. 0 Standard format (11 bit) 1 Extended format (29 bit) S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 325 Freescale’s Scalable Controller Area Network (S12MSCANV3) Module Base + 0x00X2 7 6 5 4 3 2 1 0 R W Reset: x x x x x x x x = Unused; always read ‘x’ Figure 11-32. Identifier Register 2 — Standard Mapping Module Base + 0x00X3 7 6 5 4 3 2 1 0 R W Reset: x x x x x x x x = Unused; always read ‘x’ Figure 11-33. Identifier Register 3 — Standard Mapping 11.3.3.2 Data Segment Registers (DSR0-7) The eight data segment registers, each with bits DB[7:0], contain the data to be transmitted or received. The number of bytes to be transmitted or received is determined by the data length code in the corresponding DLR register. Module Base + 0x0004 (DSR0) 0x0005 (DSR1) 0x0006 (DSR2) 0x0007 (DSR3) 0x0008 (DSR4) 0x0009 (DSR5) 0x000A (DSR6) 0x000B (DSR7) 7 R DB7 W 6 DB6 5 DB5 4 DB4 3 DB3 2 DB2 1 DB1 0 DB0 Reset: x x x x x x x x Figure 11-34. Data Segment Registers (DSR0–DSR7) — Extended Identifier Mapping S12XS-Family Reference Manual, Rev. 1.03 326 PRELIMINARY Freescale Semiconductor Freescale’s Scalable Controller Area Network (S12MSCANV3) Table 11-32. DSR0–DSR7 Register Field Descriptions Field Description 7:0 Data bits 7:0 DB[7:0] 11.3.3.3 Data Length Register (DLR) This register keeps the data length field of the CAN frame. Module Base + 0x00XB 7 6 5 4 3 2 1 R DLC3 DLC2 DLC1 W Reset: x x x x x x x = Unused; always read “x” Figure 11-35. Data Length Register (DLR) — Extended Identifier Mapping 0 DLC0 x Table 11-33. DLR Register Field Descriptions Field Description 3:0 DLC[3:0] Data Length Code Bits — The data length code contains the number of bytes (data byte count) of the respective message. During the transmission of a remote frame, the data length code is transmitted as programmed while the number of transmitted data bytes is always 0. The data byte count ranges from 0 to 8 for a data frame. Table 11-34 shows the effect of setting the DLC bits. DLC3 0 0 0 0 0 0 0 0 1 Table 11-34. Data Length Codes Data Length Code DLC2 0 0 0 0 1 1 1 1 0 DLC1 0 0 1 1 0 0 1 1 0 DLC0 0 1 0 1 0 1 0 1 0 Data Byte Count 0 1 2 3 4 5 6 7 8 S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 327 Freescale’s Scalable Controller Area Network (S12MSCANV3) 11.3.3.4 Transmit Buffer Priority Register (TBPR) This register defines the local priority of the associated message buffer. The local priority is used for the internal prioritization process of the MSCAN and is defined to be highest for the smallest binary number. The MSCAN implements the following internal prioritization mechanisms: • All transmission buffers with a cleared TXEx flag participate in the prioritization immediately before the SOF (start of frame) is sent. • The transmission buffer with the lowest local priority field wins the prioritization. In cases of more than one buffer having the same lowest priority, the message buffer with the lower index number wins. Module Base + 0xXXXD 7 R PRIO7 W 6 PRIO6 5 PRIO5 4 PRIO4 3 PRIO3 2 PRIO2 1 PRIO1 0 PRIO0 Reset: 0 0 0 0 0 0 0 0 Figure 11-36. Transmit Buffer Priority Register (TBPR) Read: Anytime when TXEx flag is set (see Section 11.3.2.7, “MSCAN Transmitter Flag Register (CANTFLG)”) and the corresponding transmit buffer is selected in CANTBSEL (see Section 11.3.2.11, “MSCAN Transmit Buffer Selection Register (CANTBSEL)”). Write: Anytime when TXEx flag is set (see Section 11.3.2.7, “MSCAN Transmitter Flag Register (CANTFLG)”) and the corresponding transmit buffer is selected in CANTBSEL (see Section 11.3.2.11, “MSCAN Transmit Buffer Selection Register (CANTBSEL)”). 11.3.3.5 Time Stamp Register (TSRH–TSRL) If the TIME bit is enabled, the MSCAN will write a time stamp to the respective registers in the active transmit or receive buffer right after the EOF of a valid message on the CAN bus (see Section 11.3.2.1, “MSCAN Control Register 0 (CANCTL0)”). In case of a transmission, the CPU can only read the time stamp after the respective transmit buffer has been flagged empty. The timer value, which is used for stamping, is taken from a free running internal CAN bit clock. A timer overrun is not indicated by the MSCAN. The timer is reset (all bits set to 0) during initialization mode. The CPU can only read the time stamp registers. Module Base + 0xXXXE R W Reset: 7 TSR15 x 6 TSR14 5 TSR13 4 TSR12 3 TSR11 2 TSR10 x x x x x Figure 11-37. Time Stamp Register — High Byte (TSRH) 1 TSR9 x 0 TSR8 x S12XS-Family Reference Manual, Rev. 1.03 328 PRELIMINARY Freescale Semiconductor Freescale’s Scalable Controller Area Network (S12MSCANV3) Module Base + 0xXXXF 7 R TSR7 6 TSR6 5 TSR5 4 TSR4 3 TSR3 2 TSR2 1 TSR1 0 TSR0 W Reset: x x x x x x x x Figure 11-38. Time Stamp Register — Low Byte (TSRL) Read: Anytime when TXEx flag is set (see Section 11.3.2.7, “MSCAN Transmitter Flag Register (CANTFLG)”) and the corresponding transmit buffer is selected in CANTBSEL (see Section 11.3.2.11, “MSCAN Transmit Buffer Selection Register (CANTBSEL)”). Write: Unimplemented 11.4 Functional Description 11.4.1 General This section provides a complete functional description of the MSCAN. It describes each of the features and modes listed in the introduction. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 329 Freescale’s Scalable Controller Area Network (S12MSCANV3) 11.4.2 Message Storage CAN Receive / Transmit Engine CPU12 Memory Mapped I/O MSCAN Receiver Rx0 Rx1 Rx2 Rx3 Rx4 RXF CPU bus RxBG RxFG Tx0 TXE0 TxBG MSCAN TxFG PRIO Tx1 TXE1 PRIO Tx2 TXE2 CPU bus TxBG Transmitter PRIO Figure 11-39. User Model for Message Buffer Organization MSCAN facilitates a sophisticated message storage system which addresses the requirements of a broad range of network applications. S12XS-Family Reference Manual, Rev. 1.03 330 PRELIMINARY Freescale Semiconductor Freescale’s Scalable Controller Area Network (S12MSCANV3) 11.4.2.1 Message Transmit Background Modern application layer software is built upon two fundamental assumptions: • Any CAN node is able to send out a stream of scheduled messages without releasing the CAN bus between the two messages. Such nodes arbitrate for the CAN bus immediately after sending the previous message and only release the CAN bus in case of lost arbitration. • The internal message queue within any CAN node is organized such that the highest priority message is sent out first, if more than one message is ready to be sent. The behavior described in the bullets above cannot be achieved with a single transmit buffer. That buffer must be reloaded immediately after the previous message is sent. This loading process lasts a finite amount of time and must be completed within the inter-frame sequence (IFS) to be able to send an uninterrupted stream of messages. Even if this is feasible for limited CAN bus speeds, it requires that the CPU reacts with short latencies to the transmit interrupt. A double buffer scheme de-couples the reloading of the transmit buffer from the actual message sending and, therefore, reduces the reactiveness requirements of the CPU. Problems can arise if the sending of a message is finished while the CPU re-loads the second buffer. No buffer would then be ready for transmission, and the CAN bus would be released. At least three transmit buffers are required to meet the first of the above requirements under all circumstances. The MSCAN has three transmit buffers. The second requirement calls for some sort of internal prioritization which the MSCAN implements with the “local priority” concept described in Section 11.4.2.2, “Transmit Structures.” 11.4.2.2 Transmit Structures The MSCAN triple transmit buffer scheme optimizes real-time performance by allowing multiple messages to be set up in advance. The three buffers are arranged as shown in Figure 11-39. All three buffers have a 13-byte data structure similar to the outline of the receive buffers (see Section 11.3.3, “Programmer’s Model of Message Storage”). An additional Section 11.3.3.4, “Transmit Buffer Priority Register (TBPR) contains an 8-bit local priority field (PRIO) (see Section 11.3.3.4, “Transmit Buffer Priority Register (TBPR)”). The remaining two bytes are used for time stamping of a message, if required (see Section 11.3.3.5, “Time Stamp Register (TSRH–TSRL)”). To transmit a message, the CPU must identify an available transmit buffer, which is indicated by a set transmitter buffer empty (TXEx) flag (see Section 11.3.2.7, “MSCAN Transmitter Flag Register (CANTFLG)”). If a transmit buffer is available, the CPU must set a pointer to this buffer by writing to the CANTBSEL register (see Section 11.3.2.11, “MSCAN Transmit Buffer Selection Register (CANTBSEL)”). This makes the respective buffer accessible within the CANTXFG address space (see Section 11.3.3, “Programmer’s Model of Message Storage”). The algorithmic feature associated with the CANTBSEL register simplifies the transmit buffer selection. In addition, this scheme makes the handler software simpler because only one address area is applicable for the transmit process, and the required address space is minimized. The CPU then stores the identifier, the control bits, and the data content into one of the transmit buffers. Finally, the buffer is flagged as ready for transmission by clearing the associated TXE flag. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 331 Freescale’s Scalable Controller Area Network (S12MSCANV3) The MSCAN then schedules the message for transmission and signals the successful transmission of the buffer by setting the associated TXE flag. A transmit interrupt (see Section 11.4.7.2, “Transmit Interrupt”) is generated1 when TXEx is set and can be used to drive the application software to re-load the buffer. If more than one buffer is scheduled for transmission when the CAN bus becomes available for arbitration, the MSCAN uses the local priority setting of the three buffers to determine the prioritization. For this purpose, every transmit buffer has an 8-bit local priority field (PRIO). The application software programs this field when the message is set up. The local priority reflects the priority of this particular message relative to the set of messages being transmitted from this node. The lowest binary value of the PRIO field is defined to be the highest priority. The internal scheduling process takes place whenever the MSCAN arbitrates for the CAN bus. This is also the case after the occurrence of a transmission error. When a high priority message is scheduled by the application software, it may become necessary to abort a lower priority message in one of the three transmit buffers. Because messages that are already in transmission cannot be aborted, the user must request the abort by setting the corresponding abort request bit (ABTRQ) (see Section 11.3.2.9, “MSCAN Transmitter Message Abort Request Register (CANTARQ)”.) The MSCAN then grants the request, if possible, by: 1. Setting the corresponding abort acknowledge flag (ABTAK) in the CANTAAK register. 2. Setting the associated TXE flag to release the buffer. 3. Generating a transmit interrupt. The transmit interrupt handler software can determine from the setting of the ABTAK flag whether the message was aborted (ABTAK = 1) or sent (ABTAK = 0). 11.4.2.3 Receive Structures The received messages are stored in a five stage input FIFO. The five message buffers are alternately mapped into a single memory area (see Figure 11-39). The background receive buffer (RxBG) is exclusively associated with the MSCAN, but the foreground receive buffer (RxFG) is addressable by the CPU (see Figure 11-39). This scheme simplifies the handler software because only one address area is applicable for the receive process. All receive buffers have a size of 15 bytes to store the CAN control bits, the identifier (standard or extended), the data contents, and a time stamp, if enabled (see Section 11.3.3, “Programmer’s Model of Message Storage”). The receiver full flag (RXF) (see Section 11.3.2.5, “MSCAN Receiver Flag Register (CANRFLG)”) signals the status of the foreground receive buffer. When the buffer contains a correctly received message with a matching identifier, this flag is set. On reception, each message is checked to see whether it passes the filter (see Section 11.4.3, “Identifier Acceptance Filter”) and simultaneously is written into the active RxBG. After successful reception of a valid message, the MSCAN shifts the content of RxBG into the receiver FIFO2, sets the RXF flag, and generates a receive interrupt (see Section 11.4.7.3, “Receive Interrupt”) to the CPU3. The user’s receive handler must read the received message from the RxFG and then reset the RXF flag to acknowledge the interrupt and to release the foreground buffer. A new message, which can follow immediately after the IFS field of the CAN frame, is received into the next available RxBG. If the MSCAN receives an invalid 1. The transmit interrupt occurs only if not masked. A polling scheme can be applied on TXEx also. 2. Only if the RXF flag is not set. 3. The receive interrupt occurs only if not masked. A polling scheme can be applied on RXF also. S12XS-Family Reference Manual, Rev. 1.03 332 PRELIMINARY Freescale Semiconductor Freescale’s Scalable Controller Area Network (S12MSCANV3) message in its RxBG (wrong identifier, transmission errors, etc.) the actual contents of the buffer will be over-written by the next message. The buffer will then not be shifted into the FIFO. When the MSCAN module is transmitting, the MSCAN receives its own transmitted messages into the background receive buffer, RxBG, but does not shift it into the receiver FIFO, generate a receive interrupt, or acknowledge its own messages on the CAN bus. The exception to this rule is in loopback mode (see Section 11.3.2.2, “MSCAN Control Register 1 (CANCTL1)”) where the MSCAN treats its own messages exactly like all other incoming messages. The MSCAN receives its own transmitted messages in the event that it loses arbitration. If arbitration is lost, the MSCAN must be prepared to become a receiver. An overrun condition occurs when all receive message buffers in the FIFO are filled with correctly received messages with accepted identifiers and another message is correctly received from the CAN bus with an accepted identifier. The latter message is discarded and an error interrupt with overrun indication is generated if enabled (see Section 11.4.7.5, “Error Interrupt”). The MSCAN remains able to transmit messages while the receiver FIFO being filled, but all incoming messages are discarded. As soon as a receive buffer in the FIFO is available again, new valid messages will be accepted. 11.4.3 Identifier Acceptance Filter The MSCAN identifier acceptance registers (see Section 11.3.2.12, “MSCAN Identifier Acceptance Control Register (CANIDAC)”) define the acceptable patterns of the standard or extended identifier (ID[10:0] or ID[28:0]). Any of these bits can be marked ‘don’t care’ in the MSCAN identifier mask registers (see Section 11.3.2.18, “MSCAN Identifier Mask Registers (CANIDMR0–CANIDMR7)”). A filter hit is indicated to the application software by a set receive buffer full flag (RXF = 1) and three bits in the CANIDAC register (see Section 11.3.2.12, “MSCAN Identifier Acceptance Control Register (CANIDAC)”). These identifier hit flags (IDHIT[2:0]) clearly identify the filter section that caused the acceptance. They simplify the application software’s task to identify the cause of the receiver interrupt. If more than one hit occurs (two or more filters match), the lower hit has priority. A very flexible programmable generic identifier acceptance filter has been introduced to reduce the CPU interrupt loading. The filter is programmable to operate in four different modes (see Bosch CAN 2.0A/B protocol specification): • Two identifier acceptance filters, each to be applied to: — The full 29 bits of the extended identifier and to the following bits of the CAN 2.0B frame: – Remote transmission request (RTR) – Identifier extension (IDE) – Substitute remote request (SRR) — The 11 bits of the standard identifier plus the RTR and IDE bits of the CAN 2.0A/B messages1. This mode implements two filters for a full length CAN 2.0B compliant extended identifier. Figure 11-40 shows how the first 32-bit filter bank (CANIDAR0–CANIDAR3, CANIDMR0–CANIDMR3) produces a filter 0 hit. Similarly, the second filter bank (CANIDAR4–CANIDAR7, CANIDMR4–CANIDMR7) produces a filter 1 hit. • Four identifier acceptance filters, each to be applied to 1. Although this mode can be used for standard identifiers, it is recommended to use the four or eight identifier acceptance filters for standard identifiers S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 333 Freescale’s Scalable Controller Area Network (S12MSCANV3) — a) the 14 most significant bits of the extended identifier plus the SRR and IDE bits of CAN 2.0B messages or — b) the 11 bits of the standard identifier, the RTR and IDE bits of CAN 2.0A/B messages. Figure 11-41 shows how the first 32-bit filter bank (CANIDAR0–CANIDA3, CANIDMR0–3CANIDMR) produces filter 0 and 1 hits. Similarly, the second filter bank (CANIDAR4–CANIDAR7, CANIDMR4–CANIDMR7) produces filter 2 and 3 hits. • Eight identifier acceptance filters, each to be applied to the first 8 bits of the identifier. This mode implements eight independent filters for the first 8 bits of a CAN 2.0A/B compliant standard identifier or a CAN 2.0B compliant extended identifier. Figure 11-42 shows how the first 32-bit filter bank (CANIDAR0–CANIDAR3, CANIDMR0–CANIDMR3) produces filter 0 to 3 hits. Similarly, the second filter bank (CANIDAR4–CANIDAR7, CANIDMR4–CANIDMR7) produces filter 4 to 7 hits. • Closed filter. No CAN message is copied into the foreground buffer RxFG, and the RXF flag is never set. CAN 2.0B Extended Identifier ID28 IDR0 ID21 ID20 IDR1 ID15 ID14 IDR2 CAN 2.0A/B Standard Identifier ID10 IDR0 ID3 ID2 IDR1 IDE ID10 IDR2 ID7 ID6 IDR3 RTR ID3 ID10 IDR3 ID3 AM7 CANIDMR0 AM0 AM7 CANIDMR1 AM0 AM7 CANIDMR2 AM0 AM7 CANIDMR3 AM0 AC7 CANIDAR0 AC0 AC7 CANIDAR1 AC0 AC7 CANIDAR2 AC0 AC7 CANIDAR3 AC0 ID Accepted (Filter 0 Hit) Figure 11-40. 32-bit Maskable Identifier Acceptance Filter S12XS-Family Reference Manual, Rev. 1.03 334 PRELIMINARY Freescale Semiconductor Freescale’s Scalable Controller Area Network (S12MSCANV3) CAN 2.0B Extended Identifier ID28 IDR0 ID21 ID20 IDR1 ID15 ID14 IDR2 CAN 2.0A/B Standard Identifier ID10 IDR0 ID3 ID2 IDR1 IDE ID10 IDR2 ID7 ID6 IDR3 RTR ID3 ID10 IDR3 ID3 AM7 CANIDMR0 AM0 AM7 CANIDMR1 AM0 AC7 CANIDAR0 AC0 AC7 CANIDAR1 AC0 ID Accepted (Filter 0 Hit) AM7 CANIDMR2 AM0 AM7 CANIDMR3 AM0 AC7 CANIDAR2 AC0 AC7 CANIDAR3 AC0 ID Accepted (Filter 1 Hit) Figure 11-41. 16-bit Maskable Identifier Acceptance Filters S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 335 Freescale’s Scalable Controller Area Network (S12MSCANV3) CAN 2.0B Extended Identifier ID28 IDR0 ID21 ID20 IDR1 ID15 ID14 IDR2 CAN 2.0A/B Standard Identifier ID10 IDR0 ID3 ID2 IDR1 IDE ID10 IDR2 ID7 ID6 IDR3 RTR ID3 ID10 IDR3 ID3 AM7 CIDMR0 AM0 AC7 CIDAR0 AC0 ID Accepted (Filter 0 Hit) AM7 CIDMR1 AM0 AC7 CIDAR1 AC0 ID Accepted (Filter 1 Hit) AM7 CIDMR2 AM0 AC7 CIDAR2 AC0 ID Accepted (Filter 2 Hit) AM7 CIDMR3 AM0 AC7 CIDAR3 AC0 ID Accepted (Filter 3 Hit) Figure 11-42. 8-bit Maskable Identifier Acceptance Filters S12XS-Family Reference Manual, Rev. 1.03 336 PRELIMINARY Freescale Semiconductor Freescale’s Scalable Controller Area Network (S12MSCANV3) 11.4.3.1 Protocol Violation Protection The MSCAN protects the user from accidentally violating the CAN protocol through programming errors. The protection logic implements the following features: • The receive and transmit error counters cannot be written or otherwise manipulated. • All registers which control the configuration of the MSCAN cannot be modified while the MSCAN is on-line. The MSCAN has to be in Initialization Mode. The corresponding INITRQ/INITAK handshake bits in the CANCTL0/CANCTL1 registers (see Section 11.3.2.1, “MSCAN Control Register 0 (CANCTL0)”) serve as a lock to protect the following registers: — MSCAN control 1 register (CANCTL1) — MSCAN bus timing registers 0 and 1 (CANBTR0, CANBTR1) — MSCAN identifier acceptance control register (CANIDAC) — MSCAN identifier acceptance registers (CANIDAR0–CANIDAR7) — MSCAN identifier mask registers (CANIDMR0–CANIDMR7) • The TXCAN pin is immediately forced to a recessive state when the MSCAN goes into the power down mode or initialization mode (see Section 11.4.5.6, “MSCAN Power Down Mode,” and Section 11.4.5.5, “MSCAN Initialization Mode”). • The MSCAN enable bit (CANE) is writable only once in normal system operation modes, which provides further protection against inadvertently disabling the MSCAN. 11.4.3.2 Clock System Figure 11-43 shows the structure of the MSCAN clock generation circuitry. Bus Clock MSCAN Oscillator Clock CLKSRC CANCLK Prescaler (1 .. 64) CLKSRC Time quanta clock (Tq) Figure 11-43. MSCAN Clocking Scheme The clock source bit (CLKSRC) in the CANCTL1 register (11.3.2.2/11-300) defines whether the internal CANCLK is connected to the output of a crystal oscillator (oscillator clock) or to the bus clock. The clock source has to be chosen such that the tight oscillator tolerance requirements (up to 0.4%) of the CAN protocol are met. Additionally, for high CAN bus rates (1 Mbps), a 45% to 55% duty cycle of the clock is required. If the bus clock is generated from a PLL, it is recommended to select the oscillator clock rather than the bus clock due to jitter considerations, especially at the faster CAN bus rates. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 337 Freescale’s Scalable Controller Area Network (S12MSCANV3) For microcontrollers without a clock and reset generator (CRG), CANCLK is driven from the crystal oscillator (oscillator clock). A programmable prescaler generates the time quanta (Tq) clock from CANCLK. A time quantum is the atomic unit of time handled by the MSCAN. Tq= (---P----r---e----s-f--c-C---aA----lN--e--C-r---L---v-K--a----l--u----e----) Eqn. 11-2 A bit time is subdivided into three segments as described in the Bosch CAN specification. (see Figure 1144): • SYNC_SEG: This segment has a fixed length of one time quantum. Signal edges are expected to happen within this section. • Time Segment 1: This segment includes the PROP_SEG and the PHASE_SEG1 of the CAN standard. It can be programmed by setting the parameter TSEG1 to consist of 4 to 16 time quanta. • Time Segment 2: This segment represents the PHASE_SEG2 of the CAN standard. It can be programmed by setting the TSEG2 parameter to be 2 to 8 time quanta long. Bit Rate= (---n----u----m------b----e---r------o----f---f--TT---q-i--m-----e-------Q-----u----a----n----t--a----) Eqn. 11-3 NRZ Signal SYNC_SEG Time Segment 1 (PROP_SEG + PHASE_SEG1) Time Segment 2 (PHASE_SEG2) 1 4 ... 16 8 ... 25 Time Quanta = 1 Bit Time 2 ... 8 Transmit Point Sample Point (single or triple sampling) Figure 11-44. Segments within the Bit Time S12XS-Family Reference Manual, Rev. 1.03 338 PRELIMINARY Freescale Semiconductor Freescale’s Scalable Controller Area Network (S12MSCANV3) Table 11-35. Time Segment Syntax Syntax SYNC_SEG Transmit Point Sample Point Description System expects transitions to occur on the CAN bus during this period. A node in transmit mode transfers a new value to the CAN bus at this point. A node in receive mode samples the CAN bus at this point. If the three samples per bit option is selected, then this point marks the position of the third sample. The synchronization jump width (see the Bosch CAN specification for details) can be programmed in a range of 1 to 4 time quanta by setting the SJW parameter. The SYNC_SEG, TSEG1, TSEG2, and SJW parameters are set by programming the MSCAN bus timing registers (CANBTR0, CANBTR1) (see Section 11.3.2.3, “MSCAN Bus Timing Register 0 (CANBTR0)” and Section 11.3.2.4, “MSCAN Bus Timing Register 1 (CANBTR1)”). Table 11-36 gives an overview of the CAN compliant segment settings and the related parameter values. NOTE It is the user’s responsibility to ensure the bit time settings are in compliance with the CAN standard. Table 11-36. CAN Standard Compliant Bit Time Segment Settings Time Segment 1 5 .. 10 4 .. 11 5 .. 12 6 .. 13 7 .. 14 8 .. 15 9 .. 16 TSEG1 4 .. 9 3 .. 10 4 .. 11 5 .. 12 6 .. 13 7 .. 14 8 .. 15 Time Segment 2 2 3 4 5 6 7 8 TSEG2 1 2 3 4 5 6 7 Synchronization Jump Width 1 .. 2 1 .. 3 1 .. 4 1 .. 4 1 .. 4 1 .. 4 1 .. 4 SJW 0 .. 1 0 .. 2 0 .. 3 0 .. 3 0 .. 3 0 .. 3 0 .. 3 11.4.4 Modes of Operation 11.4.4.1 Normal Modes The MSCAN module behaves as described within this specification in all normal system operation modes. 11.4.4.2 Special Modes The MSCAN module behaves as described within this specification in all special system operation modes. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 339 Freescale’s Scalable Controller Area Network (S12MSCANV3) 11.4.4.3 Emulation Modes In all emulation modes, the MSCAN module behaves just like normal system operation modes as described within this specification. 11.4.4.4 Listen-Only Mode In an optional CAN bus monitoring mode (listen-only), the CAN node is able to receive valid data frames and valid remote frames, but it sends only “recessive” bits on the CAN bus. In addition, it cannot start a transmision. If the MAC sub-layer is required to send a “dominant” bit (ACK bit, overload flag, or active error flag), the bit is rerouted internally so that the MAC sub-layer monitors this “dominant” bit, although the CAN bus may remain in recessive state externally. 11.4.4.5 Security Modes The MSCAN module has no security features. 11.4.5 Low-Power Options If the MSCAN is disabled (CANE = 0), the MSCAN clocks are stopped for power saving. If the MSCAN is enabled (CANE = 1), the MSCAN has two additional modes with reduced power consumption, compared to normal mode: sleep and power down mode. In sleep mode, power consumption is reduced by stopping all clocks except those to access the registers from the CPU side. In power down mode, all clocks are stopped and no power is consumed. Table 11-37 summarizes the combinations of MSCAN and CPU modes. A particular combination of modes is entered by the given settings on the CSWAI and SLPRQ/SLPAK bits. For all modes, an MSCAN wake-up interrupt can occur only if the MSCAN is in sleep mode (SLPRQ = 1 and SLPAK = 1), wake-up functionality is enabled (WUPE = 1), and the wake-up interrupt is enabled (WUPIE = 1). Table 11-37. CPU vs. MSCAN Operating Modes CPU Mode RUN WAIT STOP Normal CSWAI = X1 SLPRQ = 0 SLPAK = 0 CSWAI = 0 SLPRQ = 0 SLPAK = 0 MSCAN Mode Reduced Power Consumption Sleep Power Down Disabled (CANE=0) CSWAI = X SLPRQ = 1 SLPAK = 1 CSWAI = 0 SLPRQ = 1 SLPAK = 1 CSWAI = 1 SLPRQ = X SLPAK = X CSWAI = X SLPRQ = X SLPAK = X CSWAI = X SLPRQ = X SLPAK = X CSWAI = X SLPRQ = X SLPAK = X CSWAI = X SLPRQ = X SLPAK = X S12XS-Family Reference Manual, Rev. 1.03 340 PRELIMINARY Freescale Semiconductor 1 ‘X’ means don’t care. Freescale’s Scalable Controller Area Network (S12MSCANV3) 11.4.5.1 Operation in Run Mode As shown in Table 11-37, only MSCAN sleep mode is available as low power option when the CPU is in run mode. 11.4.5.2 Operation in Wait Mode The WAI instruction puts the MCU in a low power consumption stand-by mode. If the CSWAI bit is set, additional power can be saved in power down mode because the CPU clocks are stopped. After leaving this power down mode, the MSCAN restarts its internal controllers and enters normal mode again. While the CPU is in wait mode, the MSCAN can be operated in normal mode and generate interrupts (registers can be accessed via background debug mode). The MSCAN can also operate in any of the lowpower modes depending on the values of the SLPRQ/SLPAK and CSWAI bits as seen in Table 11-37. 11.4.5.3 Operation in Stop Mode The STOP instruction puts the MCU in a low power consumption stand-by mode. In stop mode, the MSCAN is set in power down mode regardless of the value of the SLPRQ/SLPAK and CSWAI bits (Table 11-37). 11.4.5.4 MSCAN Sleep Mode The CPU can request the MSCAN to enter this low power mode by asserting the SLPRQ bit in the CANCTL0 register. The time when the MSCAN enters sleep mode depends on a fixed synchronization delay and its current activity: • If there are one or more message buffers scheduled for transmission (TXEx = 0), the MSCAN will continue to transmit until all transmit message buffers are empty (TXEx = 1, transmitted successfully or aborted) and then goes into sleep mode. • If the MSCAN is receiving, it continues to receive and goes into sleep mode as soon as the CAN bus next becomes idle. • If the MSCAN is neither transmitting nor receiving, it immediately goes into sleep mode. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 341 Freescale’s Scalable Controller Area Network (S12MSCANV3) Bus Clock Domain CPU Sleep Request SLPRQ SLPAK Flag sync. SLPAK CAN Clock Domain SYNC sync. SLPRQ SLPRQ Flag SYNC SLPAK MSCAN in Sleep Mode Figure 11-45. Sleep Request / Acknowledge Cycle NOTE The application software must avoid setting up a transmission (by clearing one or more TXEx flag(s)) and immediately request sleep mode (by setting SLPRQ). Whether the MSCAN starts transmitting or goes into sleep mode directly depends on the exact sequence of operations. If sleep mode is active, the SLPRQ and SLPAK bits are set (Figure 11-45). The application software must use SLPAK as a handshake indication for the request (SLPRQ) to go into sleep mode. When in sleep mode (SLPRQ = 1 and SLPAK = 1), the MSCAN stops its internal clocks. However, clocks that allow register accesses from the CPU side continue to run. If the MSCAN is in bus-off state, it stops counting the 128 occurrences of 11 consecutive recessive bits due to the stopped clocks. The TXCAN pin remains in a recessive state. If RXF = 1, the message can be read and RXF can be cleared. Shifting a new message into the foreground buffer of the receiver FIFO (RxFG) does not take place while in sleep mode. It is possible to access the transmit buffers and to clear the associated TXE flags. No message abort takes place while in sleep mode. If the WUPE bit in CANCTL0 is not asserted, the MSCAN will mask any activity it detects on CAN. The RXCAN pin is therefore held internally in a recessive state. This locks the MSCAN in sleep mode. WUPE must be set before entering sleep mode to take effect. The MSCAN is able to leave sleep mode (wake up) only when: • CAN bus activity occurs and WUPE = 1 or • the CPU clears the SLPRQ bit NOTE The CPU cannot clear the SLPRQ bit before sleep mode (SLPRQ = 1 and SLPAK = 1) is active. S12XS-Family Reference Manual, Rev. 1.03 342 PRELIMINARY Freescale Semiconductor Freescale’s Scalable Controller Area Network (S12MSCANV3) After wake-up, the MSCAN waits for 11 consecutive recessive bits to synchronize to the CAN bus. As a consequence, if the MSCAN is woken-up by a CAN frame, this frame is not received. The receive message buffers (RxFG and RxBG) contain messages if they were received before sleep mode was entered. All pending actions will be executed upon wake-up; copying of RxBG into RxFG, message aborts and message transmissions. If the MSCAN remains in bus-off state after sleep mode was exited, it continues counting the 128 occurrences of 11 consecutive recessive bits. 11.4.5.5 MSCAN Initialization Mode In initialization mode, any on-going transmission or reception is immediately aborted and synchronization to the CAN bus is lost, potentially causing CAN protocol violations. To protect the CAN bus system from fatal consequences of violations, the MSCAN immediately drives the TXCAN pin into a recessive state. NOTE The user is responsible for ensuring that the MSCAN is not active when initialization mode is entered. The recommended procedure is to bring the MSCAN into sleep mode (SLPRQ = 1 and SLPAK = 1) before setting the INITRQ bit in the CANCTL0 register. Otherwise, the abort of an on-going message can cause an error condition and can impact other CAN bus devices. In initialization mode, the MSCAN is stopped. However, interface registers remain accessible. This mode is used to reset the CANCTL0, CANRFLG, CANRIER, CANTFLG, CANTIER, CANTARQ, CANTAAK, and CANTBSEL registers to their default values. In addition, the MSCAN enables the configuration of the CANBTR0, CANBTR1 bit timing registers; CANIDAC; and the CANIDAR, CANIDMR message filters. See Section 11.3.2.1, “MSCAN Control Register 0 (CANCTL0),” for a detailed description of the initialization mode. Bus Clock Domain CPU Init Request INITRQ INITAK Flag sync. INITAK SYNC CAN Clock Domain sync. INITRQ INIT Flag SYNC INITAK Figure 11-46. Initialization Request/Acknowledge Cycle Due to independent clock domains within the MSCAN, INITRQ must be synchronized to all domains by using a special handshake mechanism. This handshake causes additional synchronization delay (see Section Figure 11-46., “Initialization Request/Acknowledge Cycle”). S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 343 Freescale’s Scalable Controller Area Network (S12MSCANV3) If there is no message transfer ongoing on the CAN bus, the minimum delay will be two additional bus clocks and three additional CAN clocks. When all parts of the MSCAN are in initialization mode, the INITAK flag is set. The application software must use INITAK as a handshake indication for the request (INITRQ) to go into initialization mode. NOTE The CPU cannot clear INITRQ before initialization mode (INITRQ = 1 and INITAK = 1) is active. 11.4.5.6 MSCAN Power Down Mode The MSCAN is in power down mode (Table 11-37) when • CPU is in stop mode or • CPU is in wait mode and the CSWAI bit is set When entering the power down mode, the MSCAN immediately stops all ongoing transmissions and receptions, potentially causing CAN protocol violations. To protect the CAN bus system from fatal consequences of violations to the above rule, the MSCAN immediately drives the TXCAN pin into a recessive state. NOTE The user is responsible for ensuring that the MSCAN is not active when power down mode is entered. The recommended procedure is to bring the MSCAN into Sleep mode before the STOP or WAI instruction (if CSWAI is set) is executed. Otherwise, the abort of an ongoing message can cause an error condition and impact other CAN bus devices. In power down mode, all clocks are stopped and no registers can be accessed. If the MSCAN was not in sleep mode before power down mode became active, the module performs an internal recovery cycle after powering up. This causes some fixed delay before the module enters normal mode again. 11.4.5.7 Programmable Wake-Up Function The MSCAN can be programmed to wake up the MSCAN as soon as CAN bus activity is detected (see control bit WUPE in Section 11.3.2.1, “MSCAN Control Register 0 (CANCTL0)”). The sensitivity to existing CAN bus action can be modified by applying a low-pass filter function to the RXCAN input line while in sleep mode (see control bit WUPM in Section 11.3.2.2, “MSCAN Control Register 1 (CANCTL1)”). This feature can be used to protect the MSCAN from wake-up due to short glitches on the CAN bus lines. Such glitches can result from—for example—electromagnetic interference within noisy environments. 11.4.6 Reset Initialization The reset state of each individual bit is listed in Section 11.3.2, “Register Descriptions,” which details all the registers and their bit-fields. S12XS-Family Reference Manual, Rev. 1.03 344 PRELIMINARY Freescale Semiconductor Freescale’s Scalable Controller Area Network (S12MSCANV3) 11.4.7 Interrupts This section describes all interrupts originated by the MSCAN. It documents the enable bits and generated flags. Each interrupt is listed and described separately. 11.4.7.1 Description of Interrupt Operation The MSCAN supports four interrupt vectors (see Table 11-38), any of which can be individually masked (for details see sections from Section 11.3.2.6, “MSCAN Receiver Interrupt Enable Register (CANRIER),” to Section 11.3.2.8, “MSCAN Transmitter Interrupt Enable Register (CANTIER)”). NOTE The dedicated interrupt vector addresses are defined in the Resets and Interrupts chapter. Table 11-38. Interrupt Vectors Interrupt Source Wake-Up Interrupt (WUPIF) Error Interrupts Interrupt (CSCIF, OVRIF) Receive Interrupt (RXF) Transmit Interrupts (TXE[2:0]) CCR Mask Local Enable I bit CANRIER (WUPIE) I bit CANRIER (CSCIE, OVRIE) I bit CANRIER (RXFIE) I bit CANTIER (TXEIE[2:0]) 11.4.7.2 Transmit Interrupt At least one of the three transmit buffers is empty (not scheduled) and can be loaded to schedule a message for transmission. The TXEx flag of the empty message buffer is set. 11.4.7.3 Receive Interrupt A message is successfully received and shifted into the foreground buffer (RxFG) of the receiver FIFO. This interrupt is generated immediately after receiving the EOF symbol. The RXF flag is set. If there are multiple messages in the receiver FIFO, the RXF flag is set as soon as the next message is shifted to the foreground buffer. 11.4.7.4 Wake-Up Interrupt A wake-up interrupt is generated if activity on the CAN bus occurs during MSCAN internal sleep mode. WUPE (see Section 11.3.2.1, “MSCAN Control Register 0 (CANCTL0)”) must be enabled. 11.4.7.5 Error Interrupt An error interrupt is generated if an overrun of the receiver FIFO, error, warning, or bus-off condition occurrs. Section 11.3.2.5, “MSCAN Receiver Flag Register (CANRFLG) indicates one of the following conditions: • Overrun — An overrun condition of the receiver FIFO as described in Section 11.4.2.3, “Receive Structures,” occurred. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 345 Freescale’s Scalable Controller Area Network (S12MSCANV3) • CAN Status Change — The actual value of the transmit and receive error counters control the CAN bus state of the MSCAN. As soon as the error counters skip into a critical range (Tx/Rxwarning, Tx/Rx-error, bus-off) the MSCAN flags an error condition. The status change, which caused the error condition, is indicated by the TSTAT and RSTAT flags (see Section 11.3.2.5, “MSCAN Receiver Flag Register (CANRFLG)” and Section 11.3.2.6, “MSCAN Receiver Interrupt Enable Register (CANRIER)”). 11.4.7.6 Interrupt Acknowledge Interrupts are directly associated with one or more status flags in either the Section 11.3.2.5, “MSCAN Receiver Flag Register (CANRFLG)” or the Section 11.3.2.7, “MSCAN Transmitter Flag Register (CANTFLG).” Interrupts are pending as long as one of the corresponding flags is set. The flags in CANRFLG and CANTFLG must be reset within the interrupt handler to handshake the interrupt. The flags are reset by writing a 1 to the corresponding bit position. A flag cannot be cleared if the respective condition prevails. NOTE It must be guaranteed that the CPU clears only the bit causing the current interrupt. For this reason, bit manipulation instructions (BSET) must not be used to clear interrupt flags. These instructions may cause accidental clearing of interrupt flags which are set after entering the current interrupt service routine. 11.4.7.7 Recovery from Stop or Wait The MSCAN can recover from stop or wait via the wake-up interrupt. This interrupt can only occur if the MSCAN was in sleep mode (SLPRQ = 1 and SLPAK = 1) before entering power down mode, the wakeup option is enabled (WUPE = 1), and the wake-up interrupt is enabled (WUPIE = 1). 11.5 Initialization/Application Information 11.5.1 MSCAN initialization The procedure to initially start up the MSCAN module out of reset is as follows: 1. Assert CANE 2. Write to the configuration registers in initialization mode 3. Clear INITRQ to leave initialization mode and enter normal mode If the configuration of registers which are writable in initialization mode needs to be changed only when the MSCAN module is in normal mode: 1. Bring the module into sleep mode by setting SLPRQ and awaiting SLPAK to assert after the CAN bus becomes idle. 2. Enter initialization mode: assert INITRQ and await INITAK 3. Write to the configuration registers in initialization mode S12XS-Family Reference Manual, Rev. 1.03 346 PRELIMINARY Freescale Semiconductor Freescale’s Scalable Controller Area Network (S12MSCANV3) 4. Clear INITRQ to leave initialization mode and continue in normal mode 11.5.2 Bus-Off Recovery The bus-off recovery is user configurable. The bus-off state can either be left automatically or on user request. For reasons of backwards compatibility, the MSCAN defaults to automatic recovery after reset. In this case, the MSCAN will become error active again after counting 128 occurrences of 11 consecutive recessive bits on the CAN bus (See the Bosch CAN specification for details). If the MSCAN is configured for user request (BORM set in Section 11.3.2.2, “MSCAN Control Register 1 (CANCTL1)”), the recovery from bus-off starts after both independent events have become true: • 128 occurrences of 11 consecutive recessive bits on the CAN bus have been monitored • BOHOLD in Section 11.3.2.14, “MSCAN Miscellaneous Register (CANMISC) has been cleared by the user These two events may occur in any order. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 347 Freescale’s Scalable Controller Area Network (S12MSCANV3) S12XS-Family Reference Manual, Rev. 1.03 348 PRELIMINARY Freescale Semiconductor Chapter 12 Periodic Interrupt Timer (S12PIT24B4CV1) Table 12-1. Revision History Version Revision Effective Number Date Date 01.00 28-Apr-05 28-Apr-05 01.01 05-Jul-05 05-Jul-05 Author Description of Changes Initial Release Added application section, removed table 1-1 12.1 Introduction The period interrupt timer (PIT) is an array of 24-bit timers that can be used to trigger peripheral modules or raise periodic interrupts. Refer to Figure 12-1 for a simplified block diagram. 12.1.1 Glossary PIT ISR CCR SoC micro time bases Acronyms and Abbreviations Periodic Interrupt Timer Interrupt Service Routine Condition Code Register System on Chip clock periods of the 16-bit timer modulus down-counters, which are generated by the 8-bit modulus down-counters. 12.1.2 Features The PIT includes these features: • Four timers implemented as modulus down-counters with independent time-out periods. • Time-out periods selectable between 1 and 224 bus clock cycles. Time-out equals m*n bus clock cycles with 1 <= m <= 256 and 1 <= n <= 65536. • Timers that can be enabled individually. • Four time-out interrupts. • Four time-out trigger output signals available to trigger peripheral modules. • Start of timer channels can be aligned to each other. 12.1.3 Modes of Operation Refer to the SoC guide for a detailed explanation of the chip modes. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 349 Periodic Interrupt Timer (S12PIT24B4CV1) • Run mode This is the basic mode of operation. • Wait mode PIT operation in wait mode is controlled by the PITSWAI bit located in the PITCFLMT register. In wait mode, if the bus clock is globally enabled and if the PITSWAI bit is clear, the PIT operates like in run mode. In wait mode, if the PITSWAI bit is set, the PIT module is stalled. • Stop mode In full stop mode or pseudo stop mode, the PIT module is stalled. • Freeze mode PIT operation in freeze mode is controlled by the PITFRZ bit located in the PITCFLMT register. In freeze mode, if the PITFRZ bit is clear, the PIT operates like in run mode. In freeze mode, if the PITFRZ bit is set, the PIT module is stalled. 12.1.4 Block Diagram Figure 12-1 shows a block diagram of the PIT module. Bus Clock 8-Bit Micro Timer 0 Micro Time Base 0 8-Bit Micro Timer 1 Micro Time Base 1 16-Bit Timer 0 Time-Out 0 Interrupt 0 Interface Trigger 0 16-Bit Timer 1 Time-Out 1 Interrupt 1 Interface Trigger 1 16-Bit Timer 2 Time-Out 2 Interrupt 2 Interface Trigger 2 16-Bit Timer 3 Time-Out 3 Interrupt 3 Interface Trigger 3 Figure 12-1. PIT24B4C Block Diagram 12.2 External Signal Description The PIT module has no external pins. S12XS-Family Reference Manual, Rev. 1.03 350 PRELIMINARY Freescale Semiconductor Periodic Interrupt Timer (S12PIT24B4CV1) 12.3 Register Definition This section consists of register descriptions in address order of the PIT. Each description includes a standard register diagram with an associated figure number. Details of register bit and field function follow the register diagrams, in bit order. Register Name Bit 7 6 5 4 0x0000 R 0 PITCFLMT W PITE PITSWAI PITFRZ 0x0001 R 0 0 0 0 PITFLT W 0x0002 R 0 0 0 0 PITCE W 0x0003 R 0 0 0 0 PITMUX W 0x0004 R 0 0 0 0 PITINTE W 0x0005 R 0 0 0 0 PITTF W 0x0006 PITMTLD0 R PMTLD7 W PMTLD6 PMTLD5 PMTLD4 0x0007 PITMTLD1 R PMTLD7 W PMTLD6 PMTLD5 PMTLD4 0x0008 R PITLD0 (High) W PLD15 PLD14 PLD13 PLD12 0x0009 R PITLD0 (Low) W PLD7 PLD6 PLD5 PLD4 0x000A R PITCNT0 (High) W PCNT15 PCNT14 PCNT13 PCNT12 0x000B R PITCNT0 (Low) W PCNT7 PCNT6 PCNT5 PCNT4 0x000C R PITLD1 (High) W PLD15 PLD14 PLD13 PLD12 = Unimplemented or Reserved 3 0 0 PFLT3 PCE3 PMUX3 PINTE3 PTF3 PMTLD3 PMTLD3 PLD11 PLD3 PCNT11 PCNT3 PLD11 2 0 0 PFLT2 PCE2 PMUX2 PINTE2 PTF2 PMTLD2 PMTLD2 PLD10 PLD2 PCNT10 PCNT2 PLD10 1 Bit 0 0 0 PFLMT1 PFLMT0 0 PFLT1 0 PFLT0 PCE1 PCE0 PMUX1 PMUX0 PINTE1 PINTE0 PTF1 PTF0 PMTLD1 PMTLD0 PMTLD1 PMTLD0 PLD9 PLD8 PLD1 PLD0 PCNT9 PCNT8 PCNT1 PCNT0 PLD9 PLD8 Figure 12-2. PIT Register Summary (Sheet 1 of 2) S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 351 Periodic Interrupt Timer (S12PIT24B4CV1) Register Name 0x000D R PITLD1 (Low) W Bit 7 PLD7 6 PLD6 5 PLD5 4 PLD4 3 PLD3 2 PLD2 0x000E R PITCNT1 (High) W PCNT15 PCNT14 PCNT13 PCNT12 PCNT11 PCNT10 0x000F R PITCNT1 (Low) W PCNT7 PCNT6 PCNT5 PCNT4 PCNT3 PCNT2 0x0010 R PITLD2 (High) W PLD15 PLD14 PLD13 PLD12 PLD11 PLD10 0x0011 R PITLD2 (Low) W PLD7 PLD6 PLD5 PLD4 PLD3 PLD2 0x0012 R PITCNT2 (High) W PCNT15 PCNT14 PCNT13 PCNT12 PCNT11 PCNT10 0x0013 R PITCNT2 (Low) W PCNT7 PCNT6 PCNT5 PCNT4 PCNT3 PCNT2 0x0014 R PITLD3 (High) W PLD15 PLD14 PLD13 PLD12 PLD11 PLD10 0x0015 R PITLD3 (Low) W PLD7 PLD6 PLD5 PLD4 PLD3 PLD2 0x0016 R PITCNT3 (High) W PCNT15 PCNT14 PCNT13 PCNT12 PCNT11 PCNT10 0x0017 R PITCNT3 (Low) W PCNT7 PCNT6 PCNT5 PCNT4 PCNT3 PCNT2 0x0018−0x0027 R 0 0 0 0 0 0 RESERVED W = Unimplemented or Reserved Figure 12-2. PIT Register Summary (Sheet 2 of 2) 1 PLD1 PCNT9 PCNT1 PLD9 PLD1 PCNT9 PCNT1 PLD9 PLD1 PCNT9 PCNT1 0 Bit 0 PLD0 PCNT8 PCNT0 PLD8 PLD0 PCNT8 PCNT0 PLD8 PLD0 PCNT8 PCNT0 0 S12XS-Family Reference Manual, Rev. 1.03 352 PRELIMINARY Freescale Semiconductor Periodic Interrupt Timer (S12PIT24B4CV1) 12.3.0.1 PIT Control and Force Load Micro Timer Register (PITCFLMT) Module Base + 0x0000 7 6 5 4 3 2 1 R 0 0 0 0 PITE PITSWAI PITFRZ W PFLMT1 Reset 0 0 0 0 0 0 0 = Unimplemented or Reserved Figure 12-3. PIT Control and Force Load Micro Timer Register (PITCFLMT) Read: Anytime Write: Anytime; writes to the reserved bits have no effect Table 12-2. PITCFLMT Field Descriptions 0 0 PFLMT0 0 Field Description 7 PITE PIT Module Enable Bit — This bit enables the PIT module. If PITE is cleared, the PIT module is disabled and flag bits in the PITTF register are cleared. When PITE is set, individually enabled timers (PCE set) start downcounting with the corresponding load register values. 0 PIT disabled (lower power consumption). 1 PIT is enabled. 6 PITSWAI PIT Stop in Wait Mode Bit — This bit is used for power conservation while in wait mode. 0 PIT operates normally in wait mode 1 PIT clock generation stops and freezes the PIT module when in wait mode 5 PITFRZ PIT Counter Freeze while in Freeze Mode Bit — When during debugging a breakpoint (freeze mode) is encountered it is useful in many cases to freeze the PIT counters to avoid e.g. interrupt generation. The PITFRZ bit controls the PIT operation while in freeze mode. 0 PIT operates normally in freeze mode 1 PIT counters are stalled when in freeze mode 1:0 PFLMT[1:0] PIT Force Load Bits for Micro Timer 1:0 — These bits have only an effect if the corresponding micro timer is active and if the PIT module is enabled (PITE set). Writing a one into a PFLMT bit loads the corresponding 8-bit micro timer load register into the 8-bit micro timer down-counter. Writing a zero has no effect. Reading these bits will always return zero. Note: A micro timer force load affects all timer channels that use the corresponding micro time base. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 353 Periodic Interrupt Timer (S12PIT24B4CV1) 12.3.0.2 PIT Force Load Timer Register (PITFLT) Module Base + 0x0001 7 R 0 W Reset 0 Read: Anytime Write: Anytime 6 5 4 3 2 0 0 0 0 0 PFLT3 PFLT2 0 0 0 0 0 Figure 12-4. PIT Force Load Timer Register (PITFLT) 1 0 PFLT1 0 Table 12-3. PITFLT Field Descriptions 0 0 PFLT0 0 Field Description 3:0 PFLT[3:0] PIT Force Load Bits for Timer 3-0 — These bits have only an effect if the corresponding timer channel (PCE set) is enabled and if the PIT module is enabled (PITE set). Writing a one into a PFLT bit loads the corresponding 16-bit timer load register into the 16-bit timer down-counter. Writing a zero has no effect. Reading these bits will always return zero. 12.3.0.3 PIT Channel Enable Register (PITCE) Module Base + 0x0002 7 R 0 W Reset 0 Read: Anytime Write: Anytime 6 5 4 3 2 0 0 0 PCE3 PCE2 0 0 0 0 0 Figure 12-5. PIT Channel Enable Register (PITCE) Table 12-4. PITCE Field Descriptions 1 PCE1 0 0 PCE0 0 Field Description 3:0 PCE[3:0] PIT Enable Bits for Timer Channel 3:0 — These bits enable the PIT channels 3-0. If PCE is cleared, the PIT channel is disabled and the corresponding flag bit in the PITTF register is cleared. When PCE is set, and if the PIT module is enabled (PITE = 1) the 16-bit timer counter is loaded with the start count value and starts downcounting. 0 The corresponding PIT channel is disabled. 1 The corresponding PIT channel is enabled. S12XS-Family Reference Manual, Rev. 1.03 354 PRELIMINARY Freescale Semiconductor Periodic Interrupt Timer (S12PIT24B4CV1) 12.3.0.4 PIT Multiplex Register (PITMUX) Module Base + 0x0003 7 R 0 W Reset 0 Read: Anytime Write: Anytime 6 5 4 3 2 0 0 0 PMUX3 PMUX2 0 0 0 0 0 Figure 12-6. PIT Multiplex Register (PITMUX) 1 PMUX1 0 0 PMUX0 0 Table 12-5. PITMUX Field Descriptions Field Description 3:0 PMUX[3:0] PIT Multiplex Bits for Timer Channel 3:0 — These bits select if the corresponding 16-bit timer is connected to micro time base 1 or 0. If PMUX is modified, the corresponding 16-bit timer is switched to the other micro time base immediately. 0 The corresponding 16-bit timer counts with micro time base 0. 1 The corresponding 16-bit timer counts with micro time base 1. 12.3.0.5 PIT Interrupt Enable Register (PITINTE) Module Base + 0x0004 7 R 0 W Reset 0 Read: Anytime Write: Anytime 6 5 4 3 2 0 0 0 PINTE3 PINTE2 0 0 0 0 0 Figure 12-7. PIT Interrupt Enable Register (PITINTE) 1 PINTE1 0 0 PINTE0 0 Table 12-6. PITINTE Field Descriptions Field Description 3:0 PINTE[3:0] PIT Time-out Interrupt Enable Bits for Timer Channel 3:0 — These bits enable an interrupt service request whenever the time-out flag PTF of the corresponding PIT channel is set. When an interrupt is pending (PTF set) enabling the interrupt will immediately cause an interrupt. To avoid this, the corresponding PTF flag has to be cleared first. 0 Interrupt of the corresponding PIT channel is disabled. 1 Interrupt of the corresponding PIT channel is enabled. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 355 Periodic Interrupt Timer (S12PIT24B4CV1) 12.3.0.6 PIT Time-Out Flag Register (PITTF) Module Base + 0x0005 7 R 0 W Reset 0 6 5 4 3 2 0 0 0 PTF3 PTF2 0 0 0 0 0 Figure 12-8. PIT Time-Out Flag Register (PITTF) Read: Anytime Write: Anytime (write to clear) Table 12-7. PITTF Field Descriptions 1 PTF1 0 0 PTF0 0 Field 3:0 PTF[3:0] Description PIT Time-out Flag Bits for Timer Channel 3:0 — PTF is set when the corresponding 16-bit timer modulus down-counter and the selected 8-bit micro timer modulus down-counter have counted to zero. The flag can be cleared by writing a one to the flag bit. Writing a zero has no effect. If flag clearing by writing a one and flag setting happen in the same bus clock cycle, the flag remains set. The flag bits are cleared if the PIT module is disabled or if the corresponding timer channel is disabled. 0 Time-out of the corresponding PIT channel has not yet occurred. 1 Time-out of the corresponding PIT channel has occurred. 12.3.0.7 PIT Micro Timer Load Register 0 to 1 (PITMTLD0–1) Module Base + 0x0006 R W Reset 7 PMTLD7 0 6 PMTLD6 5 PMTLD5 4 PMTLD4 3 PMTLD3 2 PMTLD2 1 PMTLD1 0 0 0 0 0 0 Figure 12-9. PIT Micro Timer Load Register 0 (PITMTLD0) Module Base + 0x0007 R W Reset 7 PMTLD7 0 Read: Anytime Write: Anytime 6 PMTLD6 5 PMTLD5 4 PMTLD4 3 PMTLD3 2 PMTLD2 1 PMTLD1 0 0 0 0 0 0 Figure 12-10. PIT Micro Timer Load Register 1 (PITMTLD1) 0 PMTLD0 0 0 PMTLD0 0 S12XS-Family Reference Manual, Rev. 1.03 356 PRELIMINARY Freescale Semiconductor Periodic Interrupt Timer (S12PIT24B4CV1) Table 12-8. PITMTLD0–1 Field Descriptions Field Description 7:0 PIT Micro Timer Load Bits 7:0 — These bits set the 8-bit modulus down-counter load value of the micro timers. PMTLD[7:0] Writing a new value into the PITMTLD register will not restart the timer. When the micro timer has counted down to zero, the PMTLD register value will be loaded. The PFLMT bits in the PITCFLMT register can be used to immediately update the count register with the new value if an immediate load is desired. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 357 Periodic Interrupt Timer (S12PIT24B4CV1) 12.3.0.8 PIT Load Register 0 to 3 (PITLD0–3) Module Base + 0x0008, 0x0009 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 R PLD15 PLD14 PLD13 PLD12 PLD11 PLD10 PLD9 PLD8 PLD7 PLD6 PLD5 PLD4 PLD3 PLD2 PLD1 PLD0 W Reset 0 0 0 0 0 0 0000000000 Figure 12-11. PIT Load Register 0 (PITLD0) Module Base + 0x000C, 0x000D 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 R PLD15 PLD14 PLD13 PLD12 PLD11 PLD10 PLD9 PLD8 PLD7 PLD6 PLD5 PLD4 PLD3 PLD2 PLD1 PLD0 W Reset 0 0 0 0 0 0 0000000000 Figure 12-12. PIT Load Register 1 (PITLD1) Module Base + 0x0010, 0x0011 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 R PLD15 PLD14 PLD13 PLD12 PLD11 PLD10 PLD9 PLD8 PLD7 PLD6 PLD5 PLD4 PLD3 PLD2 PLD1 PLD0 W Reset 0 0 0 0 0 0 0000000000 Figure 12-13. PIT Load Register 2 (PITLD2) Module Base + 0x0014, 0x0015 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 R PLD15 PLD14 PLD13 PLD12 PLD11 PLD10 PLD9 PLD8 PLD7 PLD6 PLD5 PLD4 PLD3 PLD2 PLD1 PLD0 W Reset 0 0 0 0 0 0 0000000000 Figure 12-14. PIT Load Register 3 (PITLD3) Read: Anytime Write: Anytime Table 12-9. PITLD0–3 Field Descriptions Field Description 15:0 PLD[15:0] PIT Load Bits 15:0 — These bits set the 16-bit modulus down-counter load value. Writing a new value into the PITLD register must be a 16-bit access, to ensure data consistency. It will not restart the timer. When the timer has counted down to zero the PTF time-out flag will be set and the register value will be loaded. The PFLT bits in the PITFLT register can be used to immediately update the count register with the new value if an immediate load is desired. S12XS-Family Reference Manual, Rev. 1.03 358 PRELIMINARY Freescale Semiconductor 12.3.0.9 PIT Count Register 0 to 3 (PITCNT0–3) Periodic Interrupt Timer (S12PIT24B4CV1) Module Base + 0x000A, 0x000B 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 R PCNT PCNT PCNT PCNT PCNT PCNT PCNT PCNT PCNT PCNT PCNT PCNT PCNT PCNT PCNT PCNT W 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Reset 0 0 0 0 0 0 0000000000 Figure 12-15. PIT Count Register 0 (PITCNT0) Module Base + 0x000E, 0x000F 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 R PCNT PCNT PCNT PCNT PCNT PCNT PCNT PCNT PCNT PCNT PCNT PCNT PCNT PCNT PCNT PCNT W 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Reset 0 0 0 0 0 0 0000000000 Figure 12-16. PIT Count Register 1 (PITCNT1) Module Base + 0x0012, 0x0013 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 R PCNT PCNT PCNT PCNT PCNT PCNT PCNT PCNT PCNT PCNT PCNT PCNT PCNT PCNT PCNT PCNT W 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Reset 0 0 0 0 0 0 0000000000 Figure 12-17. PIT Count Register 2 (PITCNT2) Module Base + 0x0016, 0x0017 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 R PCNT PCNT PCNT PCNT PCNT PCNT PCNT PCNT PCNT PCNT PCNT PCNT PCNT PCNT PCNT PCNT W 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Reset 0 0 0 0 0 0 0000000000 Figure 12-18. PIT Count Register 3 (PITCNT3) Read: Anytime Write: Has no meaning or effect Table 12-10. PITCNT0–3 Field Descriptions Field Description 15:0 PIT Count Bits 15-0 — These bits represent the current 16-bit modulus down-counter value. The read access PCNT[15:0] for the count register must take place in one clock cycle as a 16-bit access. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 359 Periodic Interrupt Timer (S12PIT24B4CV1) 12.4 Functional Description Figure 12-19 shows a detailed block diagram of the PIT module. The main parts of the PIT are status, control and data registers, two 8-bit down-counters, four 16-bit down-counters and an interrupt/trigger interface. Bus Clock 4 PITFLT Register 4 PITMUX Register PITMLD0 Register 8-Bit Micro Timer 0 [0] PITMLD1 Register 8-Bit Micro Timer 1 [1] PITCFLMT Register PFLMT PMUX PFLT0 PMUX0 Timer 0 PITLD0 Register PITCNT0 Register PFLT1 [1] Timer 1 PITLD1 Register PITCNT1 Register PFLT2 [2] Timer 2 PITLD2 Register PITCNT2 Register PFLT3 [3] Timer 3 PITLD3 Register PITCNT3 Register PIT24B4C time-out 0 time-out 1 timeout 3 timeout 3 Interrupt / Trigger Interface PITTF Register PITINTE Register 4 Hardware Trigger 4 Interrupt Request Figure 12-19. PIT24B4C Detailed Block Diagram 12.4.1 Timer As shown in Figure 12-1 and Figure 12-19, the 24-bit timers are built in a two-stage architecture with four 16-bit modulus down-counters and two 8-bit modulus down-counters. The 16-bit timers are clocked with two selectable micro time bases which are generated with 8-bit modulus down-counters. Each 16-bit timer is connected to micro time base 0 or 1 via the PMUX[3:0] bit setting in the PIT Multiplex (PITMUX) register. A timer channel is enabled if the module enable bit PITE in the PIT control and force load micro timer (PITCFLMT) register is set and if the corresponding PCE bit in the PIT channel enable (PITCE) register is set. Two 8-bit modulus down-counters are used to generate two micro time bases. As soon as a micro time base is selected for an enabled timer channel, the corresponding micro timer modulus down-counter will load its start value as specified in the PITMTLD0 or PITMTLD1 register and will start down-counting. Whenever the micro timer down-counter has counted to zero the PITMTLD register is reloaded and the connected 16-bit modulus down-counters count one cycle. S12XS-Family Reference Manual, Rev. 1.03 360 PRELIMINARY Freescale Semiconductor Periodic Interrupt Timer (S12PIT24B4CV1) Whenever a 16-bit timer counter and the connected 8-bit micro timer counter have counted to zero, the PITLD register is reloaded and the corresponding time-out flag PTF in the PIT time-out flag (PITTF) register is set, as shown in Figure 12-20. The time-out period is a function of the timer load (PITLD) and micro timer load (PITMTLD) registers and the bus clock fBUS: time-out period = (PITMTLD + 1) * (PITLD + 1) / fBUS. For example, for a 40 MHz bus clock, the maximum time-out period equals: 256 * 65536 * 25 ns = 419.43 ms. The current 16-bit modulus down-counter value can be read via the PITCNT register. The micro timer down-counter values cannot be read. The 8-bit micro timers can individually be restarted by writing a one to the corresponding force load micro timer PFLMT bits in the PIT control and force load micro timer (PITCFLMT) register. The 16-bit timers can individually be restarted by writing a one to the corresponding force load timer PFLT bits in the PIT forceload timer (PITFLT) register. If desired, any group of timers and micro timers can be restarted at the same time by using one 16-bit write to the adjacent PITCFLMT and PITFLT registers with the relevant bits set, as shown in Figure 12-20. Bus Clock 8-Bit Micro 0 2 1 0 2 1 0 2 1 0 2 1 2 1 0 2 1 0 2 1 0 2 Timer Counter PITCNT Register 00 0001 0000 0001 0000 0001 0000 0001 8-Bit Force Load 16-Bit Force Load PTF Flag1 PITTRIG Time-Out Period Note 1. The PTF flag clearing depends on the software Time-Out Period After Restart Figure 12-20. PIT Trigger and Flag Signal Timing 12.4.2 Interrupt Interface Each time-out event can be used to trigger an interrupt service request. For each timer channel, an individual bit PINTE in the PIT interrupt enable (PITINTE) register exists to enable this feature. If PINTE S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 361 Periodic Interrupt Timer (S12PIT24B4CV1) is set, an interrupt service is requested whenever the corresponding time-out flag PTF in the PIT time-out flag (PITTF) register is set. The flag can be cleared by writing a one to the flag bit. NOTE Be careful when resetting the PITE, PINTE or PITCE bits in case of pending PIT interrupt requests, to avoid spurious interrupt requests. 12.4.3 Hardware Trigger The PIT module contains four hardware trigger signal lines PITTRIG[3:0], one for each timer channel. These signals can be connected on SoC level to peripheral modules enabling e.g. periodic ATD conversion (please refer to the SoC Guide for the mapping of PITTRIG[3:0] signals to peripheral modules). Whenever a timer channel time-out is reached, the corresponding PTF flag is set and the corresponding trigger signal PITTRIG triggers a rising edge. The trigger feature requires a minimum time-out period of two bus clock cycles because the trigger is asserted high for at least one bus clock cycle. For load register values PITLD = 0x0001 and PITMTLD = 0x0002 the flag setting, trigger timing and a restart with force load is shown in Figure 12-20. 12.5 Initialization 12.5.1 Startup Set the configuration registers before the PITE bit in the PITCFLMT register is set. Before PITE is set, the configuration registers can be written in arbitrary order. 12.5.2 Shutdown When the PITCE register bits, the PITINTE register bits or the PITE bit in the PITCFLMT register are cleared, the corresponding PIT interrupt flags are cleared. In case of a pending PIT interrupt request, a spurious interrupt can be generated. Two strategies, which avoid spurious interrupts, are recommended: 1. Reset the PIT interrupt flags only in an ISR. When entering the ISR, the I mask bit in the CCR is set automatically. The I mask bit must not be cleared before the PIT interrupt flags are cleared. 2. After setting the I mask bit with the SEI instruction, the PIT interrupt flags can be cleared. Then clear the I mask bit with the CLI instruction to re-enable interrupts. 12.5.3 Flag Clearing A flag is cleared by writing a one to the flag bit. Always use store or move instructions to write a one in certain bit positions. Do not use the BSET instructions. Do not use any C-constructs that compile to BSET instructions. “BSET flag_register, #mask” must not be used for flag clearing because BSET is a readmodify-write instruction which writes back the “bit-wise or” of the flag_register and the mask into the flag_register. BSET would clear all flag bits that were set, independent from the mask. For example, to clear flag bit 0 use: MOVB #$01,PITTF. S12XS-Family Reference Manual, Rev. 1.03 362 PRELIMINARY Freescale Semiconductor Periodic Interrupt Timer (S12PIT24B4CV1) 12.6 Application Information To get started quickly with the PIT24B8C module this section provides a small code example how to use the block. Please note that the example provided is only one specific case out of the possible configurations and implementations. Functionality: Generate an PIT interrupt on channel 0 every 500 PIT clock cycles. ORG LDS MOVW CODESTART ; place the program into specific ; range (to be selected) RAMEND ; load stack pointer to top of RAM #CH0_ISR,VEC_PIT_CH0 ; Change value of channel 0 ISR adr ; ******************** Start PIT Initialization ******************************************************* CLR MOVB CLR MOVB MOVW MOVB MOVB CLI PITCFLMT #$01,PITCE PITMUX #$63,PITMTLD0 #$0004,PITLD0 #$01,PITINTE #$80,PITCFLMT ; disable PIT ; enable timer channel 0 ; ch0 connected to micro timer 0 ; micro time base 0 equals 100 clock cycles ; time base 0 eq. 5 micro time bases 0 =5*100 = 500 ; enable interupt channel 0 ; enable PIT ; clear Interupt disable Mask bit ;******************** Main Program ************************************************************* MAIN: BRA * ; loop until interrupt ;******************** Channel 0 Interupt Routine *************************************************** CH0_ISR: LDAA MOVB RTI PITTF #$01,PITTF ; 8 bit read of PIT time out flags ; clear PIT channel 0 time out flag ; return to MAIN S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 363 Periodic Interrupt Timer (S12PIT24B4CV1) S12XS-Family Reference Manual, Rev. 1.03 364 PRELIMINARY Freescale Semiconductor Chapter 13 Pulse-Width Modulator (S12PWM8B8CV1) Version Revision Effective Number Date Date 01.17 08-01-2004 Author Description of Changes Added clarification of PWMIF operation in STOP and WAIT mode. Added notes on minimum pulse width of emergency shutdown signal. 13.1 Introduction The PWM definition is based on the HC12 PWM definitions. It contains the basic features from the HC11 with some of the enhancements incorporated on the HC12: center aligned output mode and four available clock sources.The PWM module has eight channels with independent control of left and center aligned outputs on each channel. Each of the eight channels has a programmable period and duty cycle as well as a dedicated counter. A flexible clock select scheme allows a total of four different clock sources to be used with the counters. Each of the modulators can create independent continuous waveforms with software-selectable duty rates from 0% to 100%. The PWM outputs can be programmed as left aligned outputs or center aligned outputs. 13.1.1 Features The PWM block includes these distinctive features: • Eight independent PWM channels with programmable period and duty cycle • Dedicated counter for each PWM channel • Programmable PWM enable/disable for each channel • Software selection of PWM duty pulse polarity for each channel • Period and duty cycle are double buffered. Change takes effect when the end of the effective period is reached (PWM counter reaches zero) or when the channel is disabled. • Programmable center or left aligned outputs on individual channels • Eight 8-bit channel or four 16-bit channel PWM resolution • Four clock sources (A, B, SA, and SB) provide for a wide range of frequencies • Programmable clock select logic • Emergency shutdown S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 365 Pulse-Width Modulator (S12PWM8B8CV1) 13.1.2 Modes of Operation There is a software programmable option for low power consumption in wait mode that disables the input clock to the prescaler. In freeze mode there is a software programmable option to disable the input clock to the prescaler. This is useful for emulation. 13.1.3 Block Diagram Figure 13-1 shows the block diagram for the 8-bit 8-channel PWM block. Bus Clock PWM8B8C PWM Channels Channel 7 Period and Duty Counter Clock Select PWM Clock Control Channel 6 Period and Duty Counter Channel 5 Period and Duty Counter Channel 4 Period and Duty Counter Enable Polarity Alignment Channel 3 Period and Duty Counter Channel 2 Period and Duty Counter Channel 1 Period and Duty Counter Channel 0 Period and Duty Counter Figure 13-1. PWM Block Diagram 13.2 External Signal Description The PWM module has a total of 8 external pins. PWM7 PWM6 PWM5 PWM4 PWM3 PWM2 PWM1 PWM0 S12XS-Family Reference Manual, Rev. 1.03 366 PRELIMINARY Freescale Semiconductor Pulse-Width Modulator (S12PWM8B8CV1) 13.2.1 PWM7 — PWM Channel 7 This pin serves as waveform output of PWM channel 7 and as an input for the emergency shutdown feature. 13.2.2 PWM6 — PWM Channel 6 This pin serves as waveform output of PWM channel 6. 13.2.3 PWM5 — PWM Channel 5 This pin serves as waveform output of PWM channel 5. 13.2.4 PWM4 — PWM Channel 4 This pin serves as waveform output of PWM channel 4. 13.2.5 PWM3 — PWM Channel 3 This pin serves as waveform output of PWM channel 3. 13.2.6 PWM3 — PWM Channel 2 This pin serves as waveform output of PWM channel 2. 13.2.7 PWM3 — PWM Channel 1 This pin serves as waveform output of PWM channel 1. 13.2.8 PWM3 — PWM Channel 0 This pin serves as waveform output of PWM channel 0. 13.3 Memory Map and Register Definition This section describes in detail all the registers and register bits in the PWM module. The special-purpose registers and register bit functions that are not normally available to device end users, such as factory test control registers and reserved registers, are clearly identified by means of shading the appropriate portions of address maps and register diagrams. Notes explaining the reasons for restricting access to the registers and functions are also explained in the individual register descriptions. 13.3.1 Module Memory Map This section describes the content of the registers in the PWM module. The base address of the PWM module is determined at the MCU level when the MCU is defined. The register decode map is fixed and begins at the first address of the module address offset. The figure below shows the registers associated S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 367 Pulse-Width Modulator (S12PWM8B8CV1) with the PWM and their relative offset from the base address. The register detail description follows the order they appear in the register map. Reserved bits within a register will always read as 0 and the write will be unimplemented. Unimplemented functions are indicated by shading the bit. . NOTE Register Address = Base Address + Address Offset, where the Base Address is defined at the MCU level and the Address Offset is defined at the module level. 13.3.2 Register Descriptions This section describes in detail all the registers and register bits in the PWM module. Register Name Bit 7 0x0000 PWME R PWME7 W 6 PWME6 5 PWME5 4 PWME4 3 PWME3 2 1 PWME2 PWME1 0x0001 R PWMPOL W PPOL7 PPOL6 PPOL5 PPOL4 PPOL3 PPOL2 PPOL1 0x0002 R PWMCLK W PCLK7 0x0003 R 0 PWMPRCLK W PCLKL6 PCKB2 PCLK5 PCKB1 PCLK4 PCKB0 PCLK3 0 PCLK2 PCKA2 PCLK1 PCKA1 0x0004 R PWMCAE W CAE7 CAE6 CAE5 CAE4 CAE3 CAE2 CAE1 0x0005 R 0 PWMCTL W CON67 CON45 CON23 CON01 PSWAI PFRZ 0x0006 R 0 0 0 0 0 0 0 PWMTST1 W 0x0007 R 0 0 0 0 0 0 0 PWMPRSC1 W 0x0008 R PWMSCLA W Bit 7 6 5 4 3 2 1 0x0009 R PWMSCLB W Bit 7 6 5 4 3 2 1 = Unimplemented or Reserved Figure 13-2. PWM Register Summary (Sheet 1 of 3) Bit 0 PWME0 PPOL0 PCLK0 PCKA0 CAE0 0 0 0 Bit 0 Bit 0 S12XS-Family Reference Manual, Rev. 1.03 368 PRELIMINARY Freescale Semiconductor Pulse-Width Modulator (S12PWM8B8CV1) Register Name 0x000A R PWMSCNTA 1 W Bit 7 0 0x000B R 0 PWMSCNTB 1 W 0x000C R PWMCNT0 W 0x000D R PWMCNT1 W 0x000E R PWMCNT2 W 0x000F R PWMCNT3 W 0x0010 R PWMCNT4 W 0x0011 R PWMCNT5 W 0x0012 R PWMCNT6 W 0x0013 R PWMCNT7 W 0x0014 R PWMPER0 W 0x0015 R PWMPER1 W 0x0016 R PWMPER2 W 0x0017 R PWMPER3 W 0x0018 R PWMPER4 W Bit 7 0 Bit 7 0 Bit 7 0 Bit 7 0 Bit 7 0 Bit 7 0 Bit 7 0 Bit 7 0 Bit 7 Bit 7 Bit 7 Bit 7 Bit 7 6 5 4 3 2 0 0 0 0 0 0 0 0 0 0 6 5 4 3 2 0 0 0 0 0 6 5 4 3 2 0 0 0 0 0 6 5 4 3 2 0 0 0 0 0 6 5 4 3 2 0 0 0 0 0 6 5 4 3 2 0 0 0 0 0 6 5 4 3 2 0 0 0 0 0 6 5 4 3 2 0 0 0 0 0 6 5 4 3 2 0 0 0 0 0 6 5 4 3 2 6 5 4 3 2 6 5 4 3 2 6 5 4 3 2 6 5 4 3 2 = Unimplemented or Reserved Figure 13-2. PWM Register Summary (Sheet 2 of 3) 1 Bit 0 0 0 0 0 1 Bit 0 0 0 1 Bit 0 0 0 1 Bit 0 0 0 1 Bit 0 0 0 1 Bit 0 0 0 1 Bit 0 0 0 1 Bit 0 0 0 1 Bit 0 0 0 1 Bit 0 1 Bit 0 1 Bit 0 1 Bit 0 1 Bit 0 S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 369 Pulse-Width Modulator (S12PWM8B8CV1) Register Name Bit 7 6 5 4 3 2 1 Bit 0 0x0019 R PWMPER5 W Bit 7 6 5 4 3 2 1 Bit 0 0x001A R PWMPER6 W Bit 7 6 5 4 3 2 1 Bit 0 0x001B R PWMPER7 W Bit 7 6 5 4 3 2 1 Bit 0 0x001C R PWMDTY0 W Bit 7 6 5 4 3 2 1 Bit 0 0x001D R PWMDTY1 W Bit 7 6 5 4 3 2 1 Bit 0 0x001E R PWMDTY2 W Bit 7 6 5 4 3 2 1 Bit 0 0x001F R PWMDTY3 W Bit 7 6 5 4 3 2 1 Bit 0 0x0010 R PWMDTY4 W Bit 7 6 5 4 3 2 1 Bit 0 0x0021 R PWMDTY5 W Bit 7 6 5 4 3 2 1 Bit 0 0x0022 R PWMDTY6 W Bit 7 6 5 4 3 2 1 Bit 0 0x0023 R PWMDTY7 W Bit 7 6 5 4 3 2 1 Bit 0 0x0024 R 0 0 PWM7IN PWMSDN W PWMIF PWMIE PWMLVL PWMRSTRT PWM7INL PWM7ENA = Unimplemented or Reserved Figure 13-2. PWM Register Summary (Sheet 3 of 3) 1 Intended for factory test purposes only. 13.3.2.1 PWM Enable Register (PWME) Each PWM channel has an enable bit (PWMEx) to start its waveform output. When any of the PWMEx bits are set (PWMEx = 1), the associated PWM output is enabled immediately. However, the actual PWM waveform is not available on the associated PWM output until its clock source begins its next cycle due to the synchronization of PWMEx and the clock source. S12XS-Family Reference Manual, Rev. 1.03 370 PRELIMINARY Freescale Semiconductor Pulse-Width Modulator (S12PWM8B8CV1) NOTE The first PWM cycle after enabling the channel can be irregular. An exception to this is when channels are concatenated. Once concatenated mode is enabled (CONxx bits set in PWMCTL register), enabling/disabling the corresponding 16-bit PWM channel is controlled by the low order PWMEx bit.In this case, the high order bytes PWMEx bits have no effect and their corresponding PWM output lines are disabled. While in run mode, if all eight PWM channels are disabled (PWME7–0 = 0), the prescaler counter shuts off for power savings. Module Base + 0x0000 R W Reset 7 PWME7 0 6 PWME6 5 PWME5 4 PWME4 3 PWME3 2 PWME2 0 0 0 0 0 Figure 13-3. PWM Enable Register (PWME) 1 PWME1 0 0 PWME0 0 Read: Anytime Write: Anytime Table 13-1. PWME Field Descriptions Field 7 PWME7 6 PWME6 5 PWME5 4 PWME4 3 PWME3 2 PWME2 Description Pulse Width Channel 7 Enable 0 Pulse width channel 7 is disabled. 1 Pulse width channel 7 is enabled. The pulse modulated signal becomes available at PWM output bit 7 when its clock source begins its next cycle. Pulse Width Channel 6 Enable 0 Pulse width channel 6 is disabled. 1 Pulse width channel 6 is enabled. The pulse modulated signal becomes available at PWM output bit6 when its clock source begins its next cycle. If CON67=1, then bit has no effect and PWM output line 6 is disabled. Pulse Width Channel 5 Enable 0 Pulse width channel 5 is disabled. 1 Pulse width channel 5 is enabled. The pulse modulated signal becomes available at PWM output bit 5 when its clock source begins its next cycle. Pulse Width Channel 4 Enable 0 Pulse width channel 4 is disabled. 1 Pulse width channel 4 is enabled. The pulse modulated signal becomes available at PWM, output bit 4 when its clock source begins its next cycle. If CON45 = 1, then bit has no effect and PWM output bit4 is disabled. Pulse Width Channel 3 Enable 0 Pulse width channel 3 is disabled. 1 Pulse width channel 3 is enabled. The pulse modulated signal becomes available at PWM, output bit 3 when its clock source begins its next cycle. Pulse Width Channel 2 Enable 0 Pulse width channel 2 is disabled. 1 Pulse width channel 2 is enabled. The pulse modulated signal becomes available at PWM, output bit 2 when its clock source begins its next cycle. If CON23 = 1, then bit has no effect and PWM output bit2 is disabled. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 371 Pulse-Width Modulator (S12PWM8B8CV1) Table 13-1. PWME Field Descriptions (continued) Field 1 PWME1 0 PWME0 Description Pulse Width Channel 1 Enable 0 Pulse width channel 1 is disabled. 1 Pulse width channel 1 is enabled. The pulse modulated signal becomes available at PWM, output bit 1 when its clock source begins its next cycle. Pulse Width Channel 0 Enable 0 Pulse width channel 0 is disabled. 1 Pulse width channel 0 is enabled. The pulse modulated signal becomes available at PWM, output bit 0 when its clock source begins its next cycle. If CON01 = 1, then bit has no effect and PWM output line0 is disabled. 13.3.2.2 PWM Polarity Register (PWMPOL) The starting polarity of each PWM channel waveform is determined by the associated PPOLx bit in the PWMPOL register. If the polarity bit is one, the PWM channel output is high at the beginning of the cycle and then goes low when the duty count is reached. Conversely, if the polarity bit is zero, the output starts low and then goes high when the duty count is reached. Module Base + 0x0001 R W Reset 7 PPOL7 0 6 PPOL6 5 PPOL5 4 PPOL4 3 PPOL3 2 PPOL2 0 0 0 0 0 Figure 13-4. PWM Polarity Register (PWMPOL) 1 PPOL1 0 0 PPOL0 0 Read: Anytime Write: Anytime NOTE PPOLx register bits can be written anytime. If the polarity is changed while a PWM signal is being generated, a truncated or stretched pulse can occur during the transition Table 13-2. PWMPOL Field Descriptions Field Description 7–0 PPOL[7:0] Pulse Width Channel 7–0 Polarity Bits 0 PWM channel 7–0 outputs are low at the beginning of the period, then go high when the duty count is reached. 1 PWM channel 7–0 outputs are high at the beginning of the period, then go low when the duty count is reached. 13.3.2.3 PWM Clock Select Register (PWMCLK) Each PWM channel has a choice of two clocks to use as the clock source for that channel as described below. S12XS-Family Reference Manual, Rev. 1.03 372 PRELIMINARY Freescale Semiconductor Pulse-Width Modulator (S12PWM8B8CV1) Module Base + 0x0002 R W Reset 7 PCLK7 0 6 PCLKL6 5 PCLK5 4 PCLK4 3 PCLK3 2 PCLK2 0 0 0 0 0 Figure 13-5. PWM Clock Select Register (PWMCLK) 1 PCLK1 0 Read: Anytime Write: Anytime NOTE Register bits PCLK0 to PCLK7 can be written anytime. If a clock select is changed while a PWM signal is being generated, a truncated or stretched pulse can occur during the transition. Table 13-3. PWMCLK Field Descriptions Field 7 PCLK7 6 PCLK6 5 PCLK5 4 PCLK4 3 PCLK3 2 PCLK2 1 PCLK1 0 PCLK0 Description Pulse Width Channel 7 Clock Select 0 Clock B is the clock source for PWM channel 7. 1 Clock SB is the clock source for PWM channel 7. Pulse Width Channel 6 Clock Select 0 Clock B is the clock source for PWM channel 6. 1 Clock SB is the clock source for PWM channel 6. Pulse Width Channel 5 Clock Select 0 Clock A is the clock source for PWM channel 5. 1 Clock SA is the clock source for PWM channel 5. Pulse Width Channel 4 Clock Select 0 Clock A is the clock source for PWM channel 4. 1 Clock SA is the clock source for PWM channel 4. Pulse Width Channel 3 Clock Select 0 Clock B is the clock source for PWM channel 3. 1 Clock SB is the clock source for PWM channel 3. Pulse Width Channel 2 Clock Select 0 Clock B is the clock source for PWM channel 2. 1 Clock SB is the clock source for PWM channel 2. Pulse Width Channel 1 Clock Select 0 Clock A is the clock source for PWM channel 1. 1 Clock SA is the clock source for PWM channel 1. Pulse Width Channel 0 Clock Select 0 Clock A is the clock source for PWM channel 0. 1 Clock SA is the clock source for PWM channel 0. 0 PCLK0 0 13.3.2.4 PWM Prescale Clock Select Register (PWMPRCLK) This register selects the prescale clock source for clocks A and B independently. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 373 Pulse-Width Modulator (S12PWM8B8CV1) Module Base + 0x0003 7 6 5 4 3 2 1 R 0 0 PCKB2 PCKB1 PCKB0 PCKA2 PCKA1 W Reset 0 0 0 0 0 0 0 = Unimplemented or Reserved Figure 13-6. PWM Prescale Clock Select Register (PWMPRCLK) Read: Anytime Write: Anytime NOTE PCKB2–0 and PCKA2–0 register bits can be written anytime. If the clock pre-scale is changed while a PWM signal is being generated, a truncated or stretched pulse can occur during the transition. Table 13-4. PWMPRCLK Field Descriptions 0 PCKA0 0 Field Description 6–4 Prescaler Select for Clock B — Clock B is one of two clock sources which can be used for channels 2, 3, 6, or PCKB[2:0] 7. These three bits determine the rate of clock B, as shown in Table 13-5. 2–0 Prescaler Select for Clock A — Clock A is one of two clock sources which can be used for channels 0, 1, 4 or PCKA[2:0] 5. These three bits determine the rate of clock A, as shown in Table 13-6. s Table 13-5. Clock B Prescaler Selects PCKB2 0 0 0 0 1 1 1 1 PCKB1 0 0 1 1 0 0 1 1 PCKB0 0 1 0 1 0 1 0 1 Value of Clock B Bus clock Bus clock / 2 Bus clock / 4 Bus clock / 8 Bus clock / 16 Bus clock / 32 Bus clock / 64 Bus clock / 128 Table 13-6. Clock A Prescaler Selects PCKA2 0 0 0 0 1 1 1 1 PCKA1 0 0 1 1 0 0 1 1 PCKA0 0 1 0 1 0 1 0 1 Value of Clock A Bus clock Bus clock / 2 Bus clock / 4 Bus clock / 8 Bus clock / 16 Bus clock / 32 Bus clock / 64 Bus clock / 128 S12XS-Family Reference Manual, Rev. 1.03 374 PRELIMINARY Freescale Semiconductor Pulse-Width Modulator (S12PWM8B8CV1) 13.3.2.5 PWM Center Align Enable Register (PWMCAE) The PWMCAE register contains eight control bits for the selection of center aligned outputs or left aligned outputs for each PWM channel. If the CAEx bit is set to a one, the corresponding PWM output will be center aligned. If the CAEx bit is cleared, the corresponding PWM output will be left aligned. See Section 13.4.2.5, “Left Aligned Outputs” and Section 13.4.2.6, “Center Aligned Outputs” for a more detailed description of the PWM output modes. Module Base + 0x0004 R W Reset 7 CAE7 0 6 CAE6 5 CAE5 4 CAE4 3 CAE3 2 CAE2 1 CAE1 0 0 0 0 0 0 Figure 13-7. PWM Center Align Enable Register (PWMCAE) Read: Anytime Write: Anytime NOTE Write these bits only when the corresponding channel is disabled. Table 13-7. PWMCAE Field Descriptions 0 CAE0 0 Field 7–0 CAE[7:0] Description Center Aligned Output Modes on Channels 7–0 0 Channels 7–0 operate in left aligned output mode. 1 Channels 7–0 operate in center aligned output mode. 13.3.2.6 PWM Control Register (PWMCTL) The PWMCTL register provides for various control of the PWM module. Module Base + 0x0005 7 6 5 4 3 2 1 0 R 0 0 CON67 CON45 CON23 CON01 PSWAI PFRZ W Reset 0 0 0 0 0 0 0 0 = Unimplemented or Reserved Figure 13-8. PWM Control Register (PWMCTL) Read: Anytime Write: Anytime There are three control bits for concatenation, each of which is used to concatenate a pair of PWM channels into one 16-bit channel. When channels 6 and 7are concatenated, channel 6 registers become the high order bytes of the double byte channel. When channels 4 and 5 are concatenated, channel 4 registers become the high order bytes of the double byte channel. When channels 2 and 3 are concatenated, channel S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 375 Pulse-Width Modulator (S12PWM8B8CV1) 2 registers become the high order bytes of the double byte channel. When channels 0 and 1 are concatenated, channel 0 registers become the high order bytes of the double byte channel. See Section 13.4.2.7, “PWM 16-Bit Functions” for a more detailed description of the concatenation PWM Function. NOTE Change these bits only when both corresponding channels are disabled. Table 13-8. PWMCTL Field Descriptions Field 7 CON67 6 CON45 5 CON23 4 CON01 3 PSWAI 2 PFREZ Description Concatenate Channels 6 and 7 0 Channels 6 and 7 are separate 8-bit PWMs. 1 Channels 6 and 7 are concatenated to create one 16-bit PWM channel. Channel 6 becomes the high order byte and channel 7 becomes the low order byte. Channel 7 output pin is used as the output for this 16-bit PWM (bit 7 of port PWMP). Channel 7 clock select control-bit determines the clock source, channel 7 polarity bit determines the polarity, channel 7 enable bit enables the output and channel 7 center aligned enable bit determines the output mode. Concatenate Channels 4 and 5 0 Channels 4 and 5 are separate 8-bit PWMs. 1 Channels 4 and 5 are concatenated to create one 16-bit PWM channel. Channel 4 becomes the high order byte and channel 5 becomes the low order byte. Channel 5 output pin is used as the output for this 16-bit PWM (bit 5 of port PWMP). Channel 5 clock select control-bit determines the clock source, channel 5 polarity bit determines the polarity, channel 5 enable bit enables the output and channel 5 center aligned enable bit determines the output mode. Concatenate Channels 2 and 3 0 Channels 2 and 3 are separate 8-bit PWMs. 1 Channels 2 and 3 are concatenated to create one 16-bit PWM channel. Channel 2 becomes the high order byte and channel 3 becomes the low order byte. Channel 3 output pin is used as the output for this 16-bit PWM (bit 3 of port PWMP). Channel 3 clock select control-bit determines the clock source, channel 3 polarity bit determines the polarity, channel 3 enable bit enables the output and channel 3 center aligned enable bit determines the output mode. Concatenate Channels 0 and 1 0 Channels 0 and 1 are separate 8-bit PWMs. 1 Channels 0 and 1 are concatenated to create one 16-bit PWM channel. Channel 0 becomes the high order byte and channel 1 becomes the low order byte. Channel 1 output pin is used as the output for this 16-bit PWM (bit 1 of port PWMP). Channel 1 clock select control-bit determines the clock source, channel 1 polarity bit determines the polarity, channel 1 enable bit enables the output and channel 1 center aligned enable bit determines the output mode. PWM Stops in Wait Mode — Enabling this bit allows for lower power consumption in wait mode by disabling the input clock to the prescaler. 0 Allow the clock to the prescaler to continue while in wait mode. 1 Stop the input clock to the prescaler whenever the MCU is in wait mode. PWM Counters Stop in Freeze Mode — In freeze mode, there is an option to disable the input clock to the prescaler by setting the PFRZ bit in the PWMCTL register. If this bit is set, whenever the MCU is in freeze mode, the input clock to the prescaler is disabled. This feature is useful during emulation as it allows the PWM function to be suspended. In this way, the counters of the PWM can be stopped while in freeze mode so that once normal program flow is continued, the counters are re-enabled to simulate real-time operations. Since the registers can still be accessed in this mode, to re-enable the prescaler clock, either disable the PFRZ bit or exit freeze mode. 0 Allow PWM to continue while in freeze mode. 1 Disable PWM input clock to the prescaler whenever the part is in freeze mode. This is useful for emulation. S12XS-Family Reference Manual, Rev. 1.03 376 PRELIMINARY Freescale Semiconductor Pulse-Width Modulator (S12PWM8B8CV1) 13.3.2.7 Reserved Register (PWMTST) This register is reserved for factory testing of the PWM module and is not available in normal modes. Module Base + 0x0006 7 6 5 4 3 2 1 0 R 0 0 0 0 0 0 0 0 W Reset 0 0 0 0 0 0 0 0 = Unimplemented or Reserved Figure 13-9. Reserved Register (PWMTST) Read: Always read $00 in normal modes Write: Unimplemented in normal modes NOTE Writing to this register when in special modes can alter the PWM functionality. 13.3.2.8 Reserved Register (PWMPRSC) This register is reserved for factory testing of the PWM module and is not available in normal modes. Module Base + 0x0007 7 6 5 4 3 2 1 0 R 0 0 0 0 0 0 0 0 W Reset 0 0 0 0 0 0 0 0 = Unimplemented or Reserved Figure 13-10. Reserved Register (PWMPRSC) Read: Always read $00 in normal modes Write: Unimplemented in normal modes NOTE Writing to this register when in special modes can alter the PWM functionality. 13.3.2.9 PWM Scale A Register (PWMSCLA) PWMSCLA is the programmable scale value used in scaling clock A to generate clock SA. Clock SA is generated by taking clock A, dividing it by the value in the PWMSCLA register and dividing that by two. Clock SA = Clock A / (2 * PWMSCLA) S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 377 Pulse-Width Modulator (S12PWM8B8CV1) NOTE When PWMSCLA = $00, PWMSCLA value is considered a full scale value of 256. Clock A is thus divided by 512. Any value written to this register will cause the scale counter to load the new scale value (PWMSCLA). Module Base + 0x0008 7 6 5 4 3 2 1 0 R Bit 7 6 5 4 3 2 1 Bit 0 W Reset 0 0 0 0 0 0 0 0 Figure 13-11. PWM Scale A Register (PWMSCLA) Read: Anytime Write: Anytime (causes the scale counter to load the PWMSCLA value) 13.3.2.10 PWM Scale B Register (PWMSCLB) PWMSCLB is the programmable scale value used in scaling clock B to generate clock SB. Clock SB is generated by taking clock B, dividing it by the value in the PWMSCLB register and dividing that by two. Clock SB = Clock B / (2 * PWMSCLB) NOTE When PWMSCLB = $00, PWMSCLB value is considered a full scale value of 256. Clock B is thus divided by 512. Any value written to this register will cause the scale counter to load the new scale value (PWMSCLB). Module Base + 0x0009 7 6 5 4 3 2 1 0 R Bit 7 6 5 4 3 2 1 Bit 0 W Reset 0 0 0 0 0 0 0 0 Figure 13-12. PWM Scale B Register (PWMSCLB) Read: Anytime Write: Anytime (causes the scale counter to load the PWMSCLB value). 13.3.2.11 Reserved Registers (PWMSCNTx) The registers PWMSCNTA and PWMSCNTB are reserved for factory testing of the PWM module and are not available in normal modes. S12XS-Family Reference Manual, Rev. 1.03 378 PRELIMINARY Freescale Semiconductor Pulse-Width Modulator (S12PWM8B8CV1) Module Base + 0x000A, 0x000B 7 6 5 4 3 2 1 0 R 0 0 0 0 0 0 0 0 W Reset 0 0 0 0 0 0 0 0 = Unimplemented or Reserved Figure 13-13. Reserved Registers (PWMSCNTx) Read: Always read $00 in normal modes Write: Unimplemented in normal modes NOTE Writing to these registers when in special modes can alter the PWM functionality. 13.3.2.12 PWM Channel Counter Registers (PWMCNTx) Each channel has a dedicated 8-bit up/down counter which runs at the rate of the selected clock source. The counter can be read at any time without affecting the count or the operation of the PWM channel. In left aligned output mode, the counter counts from 0 to the value in the period register - 1. In center aligned output mode, the counter counts from 0 up to the value in the period register and then back down to 0. Any value written to the counter causes the counter to reset to $00, the counter direction to be set to up, the immediate load of both duty and period registers with values from the buffers, and the output to change according to the polarity bit. The counter is also cleared at the end of the effective period (see Section 13.4.2.5, “Left Aligned Outputs” and Section 13.4.2.6, “Center Aligned Outputs” for more details). When the channel is disabled (PWMEx = 0), the PWMCNTx register does not count. When a channel becomes enabled (PWMEx = 1), the associated PWM counter starts at the count in the PWMCNTx register. For more detailed information on the operation of the counters, see Section 13.4.2.4, “PWM Timer Counters”. In concatenated mode, writes to the 16-bit counter by using a 16-bit access or writes to either the low or high order byte of the counter will reset the 16-bit counter. Reads of the 16-bit counter must be made by 16-bit access to maintain data coherency. NOTE Writing to the counter while the channel is enabled can cause an irregular PWM cycle to occur. Module Base + 0x000C = PWMCNT0, 0x000D = PWMCNT1, 0x000E = PWMCNT2, 0x000F = PWMCNT3 Module Base + 0x0010 = PWMCNT4, 0x0011 = PWMCNT5, 0x0012 = PWMCNT6, 0x0013 = PWMCNT7 7 6 5 4 3 2 1 0 R Bit 7 6 5 4 3 2 1 Bit 0 W 0 0 0 0 0 0 0 0 Reset 0 0 0 0 0 0 0 0 Figure 13-14. PWM Channel Counter Registers (PWMCNTx) Read: Anytime S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 379 Pulse-Width Modulator (S12PWM8B8CV1) Write: Anytime (any value written causes PWM counter to be reset to $00). 13.3.2.13 PWM Channel Period Registers (PWMPERx) There is a dedicated period register for each channel. The value in this register determines the period of the associated PWM channel. The period registers for each channel are double buffered so that if they change while the channel is enabled, the change will NOT take effect until one of the following occurs: • The effective period ends • The counter is written (counter resets to $00) • The channel is disabled In this way, the output of the PWM will always be either the old waveform or the new waveform, not some variation in between. If the channel is not enabled, then writes to the period register will go directly to the latches as well as the buffer. NOTE Reads of this register return the most recent value written. Reads do not necessarily return the value of the currently active period due to the double buffering scheme. See Section 13.4.2.3, “PWM Period and Duty” for more information. To calculate the output period, take the selected clock source period for the channel of interest (A, B, SA, or SB) and multiply it by the value in the period register for that channel: • Left aligned output (CAEx = 0) • PWMx Period = Channel Clock Period * PWMPERx Center Aligned Output (CAEx = 1) PWMx Period = Channel Clock Period * (2 * PWMPERx) For boundary case programming values, please refer to Section 13.4.2.8, “PWM Boundary Cases”. Module Base + 0x0014 = PWMPER0, 0x0015 = PWMPER1, 0x0016 = PWMPER2, 0x0017 = PWMPER3 Module Base + 0x0018 = PWMPER4, 0x0019 = PWMPER5, 0x001A = PWMPER6, 0x001B = PWMPER7 7 6 5 4 3 2 1 0 R Bit 7 6 5 4 3 2 1 Bit 0 W Reset 1 1 1 1 1 1 1 1 Figure 13-15. PWM Channel Period Registers (PWMPERx) Read: Anytime Write: Anytime S12XS-Family Reference Manual, Rev. 1.03 380 PRELIMINARY Freescale Semiconductor Pulse-Width Modulator (S12PWM8B8CV1) 13.3.2.14 PWM Channel Duty Registers (PWMDTYx) There is a dedicated duty register for each channel. The value in this register determines the duty of the associated PWM channel. The duty value is compared to the counter and if it is equal to the counter value a match occurs and the output changes state. The duty registers for each channel are double buffered so that if they change while the channel is enabled, the change will NOT take effect until one of the following occurs: • The effective period ends • The counter is written (counter resets to $00) • The channel is disabled In this way, the output of the PWM will always be either the old duty waveform or the new duty waveform, not some variation in between. If the channel is not enabled, then writes to the duty register will go directly to the latches as well as the buffer. NOTE Reads of this register return the most recent value written. Reads do not necessarily return the value of the currently active duty due to the double buffering scheme. See Section 13.4.2.3, “PWM Period and Duty” for more information. NOTE Depending on the polarity bit, the duty registers will contain the count of either the high time or the low time. If the polarity bit is one, the output starts high and then goes low when the duty count is reached, so the duty registers contain a count of the high time. If the polarity bit is zero, the output starts low and then goes high when the duty count is reached, so the duty registers contain a count of the low time. To calculate the output duty cycle (high time as a% of period) for a particular channel: • Polarity = 0 (PPOL x =0) Duty Cycle = [(PWMPERx-PWMDTYx)/PWMPERx] * 100% • Polarity = 1 (PPOLx = 1) Duty Cycle = [PWMDTYx / PWMPERx] * 100% For boundary case programming values, please refer to Section 13.4.2.8, “PWM Boundary Cases”. Module Base + 0x001C = PWMDTY0, 0x001D = PWMDTY1, 0x001E = PWMDTY2, 0x001F = PWMDTY3 Module Base + 0x0020 = PWMDTY4, 0x0021 = PWMDTY5, 0x0022 = PWMDTY6, 0x0023 = PWMDTY7 7 6 5 4 3 2 1 0 R Bit 7 6 5 4 3 2 1 Bit 0 W Reset 1 1 1 1 1 1 1 1 Figure 13-16. PWM Channel Duty Registers (PWMDTYx) Read: Anytime S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 381 Pulse-Width Modulator (S12PWM8B8CV1) Write: Anytime 13.3.2.15 PWM Shutdown Register (PWMSDN) The PWMSDN register provides for the shutdown functionality of the PWM module in the emergency cases. For proper operation, channel 7 must be driven to the active level for a minimum of two bus clocks. Module Base + 0x0024 7 6 5 4 3 2 R 0 0 PWM7IN PWMIF PWMIE PWMLVL W PWMRSTRT Reset 0 0 0 0 0 0 = Unimplemented or Reserved Figure 13-17. PWM Shutdown Register (PWMSDN) Read: Anytime Write: Anytime Table 13-9. PWMSDN Field Descriptions 1 PWM7INL 0 PWM7ENA 0 0 Field Description 7 PWMIF PWM Interrupt Flag — Any change from passive to asserted (active) state or from active to passive state will be flagged by setting the PWMIF flag = 1. The flag is cleared by writing a logic 1 to it. Writing a 0 has no effect. 0 No change on PWM7IN input. 1 Change on PWM7IN input 6 PWMIE PWM Interrupt Enable — If interrupt is enabled an interrupt to the CPU is asserted. 0 PWM interrupt is disabled. 1 PWM interrupt is enabled. 5 PWM Restart — The PWM can only be restarted if the PWM channel input 7 is de-asserted. After writing a logic PWMRSTRT 1 to the PWMRSTRT bit (trigger event) the PWM channels start running after the corresponding counter passes next “counter == 0” phase. Also, if the PWM7ENA bit is reset to 0, the PWM do not start before the counter passes $00. The bit is always read as “0”. 4 PWMLVL PWM Shutdown Output Level If active level as defined by the PWM7IN input, gets asserted all enabled PWM channels are immediately driven to the level defined by PWMLVL. 0 PWM outputs are forced to 0 1 Outputs are forced to 1. 2 PWM Channel 7 Input Status — This reflects the current status of the PWM7 pin. PWM7IN 1 PWM7INL PWM Shutdown Active Input Level for Channel 7 — If the emergency shutdown feature is enabled (PWM7ENA = 1), this bit determines the active level of the PWM7channel. 0 Active level is low 1 Active level is high 0 PWM7ENA PWM Emergency Shutdown Enable — If this bit is logic 1, the pin associated with channel 7 is forced to input and the emergency shutdown feature is enabled. All the other bits in this register are meaningful only if PWM7ENA = 1. 0 PWM emergency feature disabled. 1 PWM emergency feature is enabled. S12XS-Family Reference Manual, Rev. 1.03 382 PRELIMINARY Freescale Semiconductor 13.4 Functional Description Pulse-Width Modulator (S12PWM8B8CV1) 13.4.1 PWM Clock Select There are four available clocks: clock A, clock B, clock SA (scaled A), and clock SB (scaled B). These four clocks are based on the bus clock. Clock A and B can be software selected to be 1, 1/2, 1/4, 1/8,..., 1/64, 1/128 times the bus clock. Clock SA uses clock A as an input and divides it further with a reloadable counter. Similarly, clock SB uses clock B as an input and divides it further with a reloadable counter. The rates available for clock SA are software selectable to be clock A divided by 2, 4, 6, 8,..., or 512 in increments of divide by 2. Similar rates are available for clock SB. Each PWM channel has the capability of selecting one of two clocks, either the pre-scaled clock (clock A or B) or the scaled clock (clock SA or SB). The block diagram in Figure 13-18 shows the four different clocks and how the scaled clocks are created. 13.4.1.1 Prescale The input clock to the PWM prescaler is the bus clock. It can be disabled whenever the part is in freeze mode by setting the PFRZ bit in the PWMCTL register. If this bit is set, whenever the MCU is in freeze mode (freeze mode signal active) the input clock to the prescaler is disabled. This is useful for emulation in order to freeze the PWM. The input clock can also be disabled when all eight PWM channels are disabled (PWME7-0 = 0). This is useful for reducing power by disabling the prescale counter. Clock A and clock B are scaled values of the input clock. The value is software selectable for both clock A and clock B and has options of 1, 1/2, 1/4, 1/8, 1/16, 1/32, 1/64, or 1/128 times the bus clock. The value selected for clock A is determined by the PCKA2, PCKA1, PCKA0 bits in the PWMPRCLK register. The value selected for clock B is determined by the PCKB2, PCKB1, PCKB0 bits also in the PWMPRCLK register. 13.4.1.2 Clock Scale The scaled A clock uses clock A as an input and divides it further with a user programmable value and then divides this by 2. The scaled B clock uses clock B as an input and divides it further with a user programmable value and then divides this by 2. The rates available for clock SA are software selectable to be clock A divided by 2, 4, 6, 8,..., or 512 in increments of divide by 2. Similar rates are available for clock SB. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 383 Pulse-Width Modulator (S12PWM8B8CV1) PCKA2 PCKA1 PCKA0 Divide by Prescaler Taps: 2 4 8 16 32 64 128 Clock A Clock A/2, A/4, A/6,....A/512 M U X Clock to PWM Ch 0 8-Bit Down Counter Count = 1 Load PCLK0 M U X Clock to PWM Ch 1 PWMSCLA DIV 2 Clock SA PCLK1 M M U X Clock to PWM Ch 2 U X PCLK2 M U X Clock to PWM Ch 3 Clock B Clock B/2, B/4, B/6,....B/512 PCLK3 M U X Clock to PWM Ch 4 M 8-Bit Down Count = 1 U Counter X Load PCLK4 M U X Clock to PWM Ch 5 PWMSCLB Clock SB DIV 2 PCLK5 M U X Clock to PWM Ch 6 Bus Clock PFRZ Freeze Mode Signal PWME7-0 PCKB2 PCKB1 PCKB0 PCLK6 M U X Clock to PWM Ch 7 Prescale Scale Figure 13-18. PWM Clock Select Block Diagram PCLK7 Clock Select S12XS-Family Reference Manual, Rev. 1.03 384 PRELIMINARY Freescale Semiconductor Pulse-Width Modulator (S12PWM8B8CV1) Clock A is used as an input to an 8-bit down counter. This down counter loads a user programmable scale value from the scale register (PWMSCLA). When the down counter reaches one, a pulse is output and the 8-bit counter is re-loaded. The output signal from this circuit is further divided by two. This gives a greater range with only a slight reduction in granularity. Clock SA equals clock A divided by two times the value in the PWMSCLA register. NOTE Clock SA = Clock A / (2 * PWMSCLA) When PWMSCLA = $00, PWMSCLA value is considered a full scale value of 256. Clock A is thus divided by 512. Similarly, clock B is used as an input to an 8-bit down counter followed by a divide by two producing clock SB. Thus, clock SB equals clock B divided by two times the value in the PWMSCLB register. NOTE Clock SB = Clock B / (2 * PWMSCLB) When PWMSCLB = $00, PWMSCLB value is considered a full scale value of 256. Clock B is thus divided by 512. As an example, consider the case in which the user writes $FF into the PWMSCLA register. Clock A for this case will be E divided by 4. A pulse will occur at a rate of once every 255x4 E cycles. Passing this through the divide by two circuit produces a clock signal at an E divided by 2040 rate. Similarly, a value of $01 in the PWMSCLA register when clock A is E divided by 4 will produce a clock at an E divided by 8 rate. Writing to PWMSCLA or PWMSCLB causes the associated 8-bit down counter to be re-loaded. Otherwise, when changing rates the counter would have to count down to $01 before counting at the proper rate. Forcing the associated counter to re-load the scale register value every time PWMSCLA or PWMSCLB is written prevents this. NOTE Writing to the scale registers while channels are operating can cause irregularities in the PWM outputs. 13.4.1.3 Clock Select Each PWM channel has the capability of selecting one of two clocks. For channels 0, 1, 4, and 5 the clock choices are clock A or clock SA. For channels 2, 3, 6, and 7 the choices are clock B or clock SB. The clock selection is done with the PCLKx control bits in the PWMCLK register. NOTE Changing clock control bits while channels are operating can cause irregularities in the PWM outputs. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 385 Pulse-Width Modulator (S12PWM8B8CV1) 13.4.2 PWM Channel Timers The main part of the PWM module are the actual timers. Each of the timer channels has a counter, a period register and a duty register (each are 8-bit). The waveform output period is controlled by a match between the period register and the value in the counter. The duty is controlled by a match between the duty register and the counter value and causes the state of the output to change during the period. The starting polarity of the output is also selectable on a per channel basis. Shown below in Figure 13-19 is the block diagram for the PWM timer. Clock Source Gate (Clock Edge Sync) 8-Bit Counter PWMCNTx Up/Down Reset From Port PWMP Data Register 8-bit Compare = PWMDTYx 8-bit Compare = PWMPERx T QM U QX R PPOLx M U X To Pin Driver QT Q R CAEx PWMEx Figure 13-19. PWM Timer Channel Block Diagram 13.4.2.1 PWM Enable Each PWM channel has an enable bit (PWMEx) to start its waveform output. When any of the PWMEx bits are set (PWMEx = 1), the associated PWM output signal is enabled immediately. However, the actual PWM waveform is not available on the associated PWM output until its clock source begins its next cycle due to the synchronization of PWMEx and the clock source. An exception to this is when channels are concatenated. Refer to Section 13.4.2.7, “PWM 16-Bit Functions” for more detail. NOTE The first PWM cycle after enabling the channel can be irregular. S12XS-Family Reference Manual, Rev. 1.03 386 PRELIMINARY Freescale Semiconductor Pulse-Width Modulator (S12PWM8B8CV1) On the front end of the PWM timer, the clock is enabled to the PWM circuit by the PWMEx bit being high. There is an edge-synchronizing circuit to guarantee that the clock will only be enabled or disabled at an edge. When the channel is disabled (PWMEx = 0), the counter for the channel does not count. 13.4.2.2 PWM Polarity Each channel has a polarity bit to allow starting a waveform cycle with a high or low signal. This is shown on the block diagram as a mux select of either the Q output or the Q output of the PWM output flip flop. When one of the bits in the PWMPOL register is set, the associated PWM channel output is high at the beginning of the waveform, then goes low when the duty count is reached. Conversely, if the polarity bit is zero, the output starts low and then goes high when the duty count is reached. 13.4.2.3 PWM Period and Duty Dedicated period and duty registers exist for each channel and are double buffered so that if they change while the channel is enabled, the change will NOT take effect until one of the following occurs: • The effective period ends • The counter is written (counter resets to $00) • The channel is disabled In this way, the output of the PWM will always be either the old waveform or the new waveform, not some variation in between. If the channel is not enabled, then writes to the period and duty registers will go directly to the latches as well as the buffer. A change in duty or period can be forced into effect “immediately” by writing the new value to the duty and/or period registers and then writing to the counter. This forces the counter to reset and the new duty and/or period values to be latched. In addition, since the counter is readable, it is possible to know where the count is with respect to the duty value and software can be used to make adjustments NOTE When forcing a new period or duty into effect immediately, an irregular PWM cycle can occur. Depending on the polarity bit, the duty registers will contain the count of either the high time or the low time. 13.4.2.4 PWM Timer Counters Each channel has a dedicated 8-bit up/down counter which runs at the rate of the selected clock source (see Section 13.4.1, “PWM Clock Select” for the available clock sources and rates). The counter compares to two registers, a duty register and a period register as shown in Figure 13-19. When the PWM counter matches the duty register, the output flip-flop changes state, causing the PWM waveform to also change state. A match between the PWM counter and the period register behaves differently depending on what output mode is selected as shown in Figure 13-19 and described in Section 13.4.2.5, “Left Aligned Outputs” and Section 13.4.2.6, “Center Aligned Outputs”. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 387 Pulse-Width Modulator (S12PWM8B8CV1) Each channel counter can be read at anytime without affecting the count or the operation of the PWM channel. Any value written to the counter causes the counter to reset to $00, the counter direction to be set to up, the immediate load of both duty and period registers with values from the buffers, and the output to change according to the polarity bit. When the channel is disabled (PWMEx = 0), the counter stops. When a channel becomes enabled (PWMEx = 1), the associated PWM counter continues from the count in the PWMCNTx register. This allows the waveform to continue where it left off when the channel is reenabled. When the channel is disabled, writing “0” to the period register will cause the counter to reset on the next selected clock. NOTE If the user wants to start a new “clean” PWM waveform without any “history” from the old waveform, the user must write to channel counter (PWMCNTx) prior to enabling the PWM channel (PWMEx = 1). Generally, writes to the counter are done prior to enabling a channel in order to start from a known state. However, writing a counter can also be done while the PWM channel is enabled (counting). The effect is similar to writing the counter when the channel is disabled, except that the new period is started immediately with the output set according to the polarity bit. NOTE Writing to the counter while the channel is enabled can cause an irregular PWM cycle to occur. The counter is cleared at the end of the effective period (see Section 13.4.2.5, “Left Aligned Outputs” and Section 13.4.2.6, “Center Aligned Outputs” for more details). Table 13-10. PWM Timer Counter Conditions Counter Clears ($00) When PWMCNTx register written to any value Effective period ends Counter Counts When PWM channel is enabled (PWMEx = 1). Counts from last value in PWMCNTx. Counter Stops When PWM channel is disabled (PWMEx = 0) 13.4.2.5 Left Aligned Outputs The PWM timer provides the choice of two types of outputs, left aligned or center aligned. They are selected with the CAEx bits in the PWMCAE register. If the CAEx bit is cleared (CAEx = 0), the corresponding PWM output will be left aligned. In left aligned output mode, the 8-bit counter is configured as an up counter only. It compares to two registers, a duty register and a period register as shown in the block diagram in Figure 13-19. When the PWM counter matches the duty register the output flip-flop changes state causing the PWM waveform to also change state. A match between the PWM counter and the period register resets the counter and the output flip-flop, as shown in Figure 13-19, as well as performing a load from the double buffer period and duty register to the associated registers, as described in Section 13.4.2.3, “PWM Period and Duty”. The counter counts from 0 to the value in the period register – 1. S12XS-Family Reference Manual, Rev. 1.03 388 PRELIMINARY Freescale Semiconductor Pulse-Width Modulator (S12PWM8B8CV1) NOTE Changing the PWM output mode from left aligned to center aligned output (or vice versa) while channels are operating can cause irregularities in the PWM output. It is recommended to program the output mode before enabling the PWM channel. PPOLx = 0 PPOLx = 1 PWMDTYx Period = PWMPERx Figure 13-20. PWM Left Aligned Output Waveform To calculate the output frequency in left aligned output mode for a particular channel, take the selected clock source frequency for the channel (A, B, SA, or SB) and divide it by the value in the period register for that channel. • PWMx Frequency = Clock (A, B, SA, or SB) / PWMPERx • PWMx Duty Cycle (high time as a% of period): — Polarity = 0 (PPOLx = 0) • Duty Cycle = [(PWMPERx-PWMDTYx)/PWMPERx] * 100% — Polarity = 1 (PPOLx = 1) Duty Cycle = [PWMDTYx / PWMPERx] * 100% As an example of a left aligned output, consider the following case: Clock Source = E, where E = 10 MHz (100 ns period) PPOLx = 0 PWMPERx = 4 PWMDTYx = 1 PWMx Frequency = 10 MHz/4 = 2.5 MHz PWMx Period = 400 ns PWMx Duty Cycle = 3/4 *100% = 75% The output waveform generated is shown in Figure 13-21. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 389 Pulse-Width Modulator (S12PWM8B8CV1) E = 100 ns Duty Cycle = 75% Period = 400 ns Figure 13-21. PWM Left Aligned Output Example Waveform 13.4.2.6 Center Aligned Outputs For center aligned output mode selection, set the CAEx bit (CAEx = 1) in the PWMCAE register and the corresponding PWM output will be center aligned. The 8-bit counter operates as an up/down counter in this mode and is set to up whenever the counter is equal to $00. The counter compares to two registers, a duty register and a period register as shown in the block diagram in Figure 13-19. When the PWM counter matches the duty register, the output flip-flop changes state, causing the PWM waveform to also change state. A match between the PWM counter and the period register changes the counter direction from an up-count to a down-count. When the PWM counter decrements and matches the duty register again, the output flip-flop changes state causing the PWM output to also change state. When the PWM counter decrements and reaches zero, the counter direction changes from a down-count back to an up-count and a load from the double buffer period and duty registers to the associated registers is performed, as described in Section 13.4.2.3, “PWM Period and Duty”. The counter counts from 0 up to the value in the period register and then back down to 0. Thus the effective period is PWMPERx*2. NOTE Changing the PWM output mode from left aligned to center aligned output (or vice versa) while channels are operating can cause irregularities in the PWM output. It is recommended to program the output mode before enabling the PWM channel. PPOLx = 0 PPOLx = 1 PWMDTYx PWMDTYx PWMPERx PWMPERx Period = PWMPERx*2 Figure 13-22. PWM Center Aligned Output Waveform S12XS-Family Reference Manual, Rev. 1.03 390 PRELIMINARY Freescale Semiconductor Pulse-Width Modulator (S12PWM8B8CV1) To calculate the output frequency in center aligned output mode for a particular channel, take the selected clock source frequency for the channel (A, B, SA, or SB) and divide it by twice the value in the period register for that channel. • PWMx Frequency = Clock (A, B, SA, or SB) / (2*PWMPERx) • PWMx Duty Cycle (high time as a% of period): — Polarity = 0 (PPOLx = 0) Duty Cycle = [(PWMPERx-PWMDTYx)/PWMPERx] * 100% — Polarity = 1 (PPOLx = 1) Duty Cycle = [PWMDTYx / PWMPERx] * 100% S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 391 Pulse-Width Modulator (S12PWM8B8CV1) As an example of a center aligned output, consider the following case: Clock Source = E, where E = 10 MHz (100 ns period) PPOLx = 0 PWMPERx = 4 PWMDTYx = 1 PWMx Frequency = 10 MHz/8 = 1.25 MHz PWMx Period = 800 ns PWMx Duty Cycle = 3/4 *100% = 75% Shown in Figure 13-23 is the output waveform generated. E = 100 ns E = 100 ns DUTY CYCLE = 75% PERIOD = 800 ns Figure 13-23. PWM Center Aligned Output Example Waveform 13.4.2.7 PWM 16-Bit Functions The PWM timer also has the option of generating 8-channels of 8-bits or 4-channels of 16-bits for greater PWM resolution. This 16-bit channel option is achieved through the concatenation of two 8-bit channels. The PWMCTL register contains four control bits, each of which is used to concatenate a pair of PWM channels into one 16-bit channel. Channels 6 and 7 are concatenated with the CON67 bit, channels 4 and 5 are concatenated with the CON45 bit, channels 2 and 3 are concatenated with the CON23 bit, and channels 0 and 1 are concatenated with the CON01 bit. NOTE Change these bits only when both corresponding channels are disabled. When channels 6 and 7 are concatenated, channel 6 registers become the high order bytes of the double byte channel, as shown in Figure 13-24. Similarly, when channels 4 and 5 are concatenated, channel 4 registers become the high order bytes of the double byte channel. When channels 2 and 3 are concatenated, channel 2 registers become the high order bytes of the double byte channel. When channels 0 and 1 are concatenated, channel 0 registers become the high order bytes of the double byte channel. When using the 16-bit concatenated mode, the clock source is determined by the low order 8-bit channel clock select control bits. That is channel 7 when channels 6 and 7 are concatenated, channel 5 when channels 4 and 5 are concatenated, channel 3 when channels 2 and 3 are concatenated, and channel 1 when channels 0 and 1 are concatenated. The resulting PWM is output to the pins of the corresponding low order 8-bit channel as also shown in Figure 13-24. The polarity of the resulting PWM output is controlled by the PPOLx bit of the corresponding low order 8-bit channel as well. S12XS-Family Reference Manual, Rev. 1.03 392 PRELIMINARY Freescale Semiconductor Clock Source 7 High PWMCNT6 Pulse-Width Modulator (S12PWM8B8CV1) Low PWCNT7 Clock Source 5 Period/Duty Compare High PWMCNT4 Low PWCNT5 PWM7 Clock Source 3 Period/Duty Compare High PWMCNT2 Low PWCNT3 PWM5 Clock Source 1 Period/Duty Compare High PWMCNT0 Low PWCNT1 PWM3 Period/Duty Compare PWM1 Figure 13-24. PWM 16-Bit Mode Once concatenated mode is enabled (CONxx bits set in PWMCTL register), enabling/disabling the corresponding 16-bit PWM channel is controlled by the low order PWMEx bit. In this case, the high order bytes PWMEx bits have no effect and their corresponding PWM output is disabled. In concatenated mode, writes to the 16-bit counter by using a 16-bit access or writes to either the low or high order byte of the counter will reset the 16-bit counter. Reads of the 16-bit counter must be made by 16-bit access to maintain data coherency. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 393 Pulse-Width Modulator (S12PWM8B8CV1) Either left aligned or center aligned output mode can be used in concatenated mode and is controlled by the low order CAEx bit. The high order CAEx bit has no effect. Table 13-11 is used to summarize which channels are used to set the various control bits when in 16-bit mode. Table 13-11. 16-bit Concatenation Mode Summary CONxx CON67 CON45 CON23 CON01 PWMEx PWME7 PWME5 PWME3 PWME1 PPOLx PPOL7 PPOL5 PPOL3 PPOL1 PCLKx PCLK7 PCLK5 PCLK3 PCLK1 CAEx CAE7 CAE5 CAE3 CAE1 PWMx Output PWM7 PWM5 PWM3 PWM1 13.4.2.8 PWM Boundary Cases Table 13-12 summarizes the boundary conditions for the PWM regardless of the output mode (left aligned or center aligned) and 8-bit (normal) or 16-bit (concatenation). Table 13-12. PWM Boundary Cases PWMDTYx PWMPERx $00 (indicates no duty) >$00 $00 (indicates no duty) XX XX >$00 $001 (indicates no period) $001 (indicates no period) >= PWMPERx XX >= PWMPERx XX 1 Counter = $00 and does not count. PPOLx 1 0 1 0 1 0 PWMx Output Always low Always high Always high Always low Always high Always low 13.5 Resets The reset state of each individual bit is listed within the Section 13.3.2, “Register Descriptions” which details the registers and their bit-fields. All special functions or modes which are initialized during or just following reset are described within this section. • The 8-bit up/down counter is configured as an up counter out of reset. • All the channels are disabled and all the counters do not count. S12XS-Family Reference Manual, Rev. 1.03 394 PRELIMINARY Freescale Semiconductor Pulse-Width Modulator (S12PWM8B8CV1) 13.6 Interrupts The PWM module has only one interrupt which is generated at the time of emergency shutdown, if the corresponding enable bit (PWMIE) is set. This bit is the enable for the interrupt. The interrupt flag PWMIF is set whenever the input level of the PWM7 channel changes while PWM7ENA = 1 or when PWMENA is being asserted while the level at PWM7 is active. In stop mode or wait mode (with the PSWAI bit set), the emergency shutdown feature will drive the PWM outputs to their shutdown output levels but the PWMIF flag will not be set. A description of the registers involved and affected due to this interrupt is explained in Section 13.3.2.15, “PWM Shutdown Register (PWMSDN)”. The PWM block only generates the interrupt and does not service it. The interrupt signal name is PWM interrupt signal. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 395 Pulse-Width Modulator (S12PWM8B8CV1) S12XS-Family Reference Manual, Rev. 1.03 396 PRELIMINARY Freescale Semiconductor Chapter 14 Serial Communication Interface (S12SCIV5) Table 14-1. Revision History Revision Number V05.00 V05.01 V05.02 Revision Date Sections Affected Description of Changes 02 Jun 2003 16 Apr 2004 14 Oct 2005 14.3.2.2/14-403 - Opened three new registers using a Mode bit. 14.4.6.6/14-429 - Added Wakeup capability on Receive Input. 14.4.5.5/14-421 - Added LIN transmit collision detect capability. 14.4.2/14-414 - Added LIN break detect capability. - Updated block diagram. 14.4.4/14-416 - Updated Table 4-3 to use more general bus clock frequency. - Updated to be SRS3.0 compliant. 14.3.2.7/14-409 - Update OR and PF flag description. - Correct baud rate tolerance in 4.7.5.1 and 4.7.5.2. - Clean up classification and NDA message banners. 14.3.2.3/14-405 - Correct alternative registers address. 14.4.4/14-416 - Remove unavailable baud rate in Table1-16. 14.1 Introduction This block guide provides an overview of the serial communication interface (SCI) module. The SCI allows asynchronous serial communications with peripheral devices and other CPUs. 14.1.1 Glossary IR: InfraRed IrDA: Infrared Design Associate IRQ: Interrupt Request LIN: Local Interconnect Network LSB: Least Significant Bit MSB: Most Significant Bit NRZ: Non-Return-to-Zero RZI: Return-to-Zero-Inverted RXD: Receive Pin S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 397 Serial Communication Interface (S12SCIV5) SCI : Serial Communication Interface TXD: Transmit Pin 14.1.2 Features The SCI includes these distinctive features: • Full-duplex or single-wire operation • Standard mark/space non-return-to-zero (NRZ) format • Selectable IrDA 1.4 return-to-zero-inverted (RZI) format with programmable pulse widths • 13-bit baud rate selection • Programmable 8-bit or 9-bit data format • Separately enabled transmitter and receiver • Programmable polarity for transmitter and receiver • Programmable transmitter output parity • Two receiver wakeup methods: — Idle line wakeup — Address mark wakeup • Interrupt-driven operation with eight flags: — Transmitter empty — Transmission complete — Receiver full — Idle receiver input — Receiver overrun — Noise error — Framing error — Parity error — Receive wakeup on active edge — Transmit collision detect supporting LIN — Break Detect supporting LIN • Receiver framing error detection • Hardware parity checking • 1/16 bit-time noise detection 14.1.3 Modes of Operation The SCI functions the same in normal, special, and emulation modes. It has two low power modes, wait and stop modes. • Run mode S12XS-Family Reference Manual, Rev. 1.03 398 PRELIMINARY Freescale Semiconductor • Wait mode • Stop mode Serial Communication Interface (S12SCIV5) 14.1.4 Block Diagram Figure 14-1 is a high level block diagram of the SCI module, showing the interaction of various function blocks. RXD Data In Infrared Decoder Bus Clock Baud Rate Generator 1/16 SCI Data Register Receive Shift Register Receive & Wakeup Control Data Format Control Transmit Control IDLE Receive RDRF/OR Interrupt Generation BRKD RXEDG BERR Transmit Interrupt TDRE Generation TC SCI Interrupt Request Transmit Shift Register Infrared Encoder SCI Data Register Figure 14-1. SCI Block Diagram Data Out TXD S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 399 Serial Communication Interface (S12SCIV5) 14.2 External Signal Description The SCI module has a total of two external pins. 14.2.1 TXD — Transmit Pin The TXD pin transmits SCI (standard or infrared) data. It will idle high in either mode and is high impedance anytime the transmitter is disabled. 14.2.2 RXD — Receive Pin The RXD pin receives SCI (standard or infrared) data. An idle line is detected as a line high. This input is ignored when the receiver is disabled and should be terminated to a known voltage. 14.3 Memory Map and Register Definition This section provides a detailed description of all the SCI registers. 14.3.1 Module Memory Map and Register Definition The memory map for the SCI module is given below in Figure 14-2. The address listed for each register is the address offset. The total address for each register is the sum of the base address for the SCI module and the address offset for each register. S12XS-Family Reference Manual, Rev. 1.03 400 PRELIMINARY Freescale Semiconductor Serial Communication Interface (S12SCIV5) 14.3.2 Register Descriptions This section consists of register descriptions in address order. Each description includes a standard register diagram with an associated figure number. Writes to a reserved register locations do not have any effect and reads of these locations return a zero. Details of register bit and field function follow the register diagrams, in bit order. Register Name Bit 7 0x0000 R SCIBDH1 W IREN 6 TNP1 5 TNP0 4 3 2 SBR12 SBR11 SBR10 1 SBR9 Bit 0 SBR8 0x0001 SCIBDL1 0x0002 SCICR11 R SBR7 W R LOOPS W SBR6 SCISWAI SBR5 RSRC SBR4 M SBR3 WAKE SBR2 ILT SBR1 PE SBR0 PT 0x0000 R 0 0 0 0 SCIASR12 RXEDGIF W BERRV BERRIF BKDIF 0x0001 R 0 0 0 0 0 SCIACR12 RXEDGIE W BERRIE BKDIE 0x0002 R 0 0 0 0 0 SCIACR22 W BERRM1 BERRM0 BKDFE 0x0003 R SCICR2 W TIE TCIE RIE ILIE TE RE RWU SBK 0x0004 R TDRE TC RDRF IDLE OR NF FE PF SCISR1 W 0x0005 R 0 SCISR2 AMAP W 0 RAF TXPOL RXPOL BRK13 TXDIR 0x0006 R R8 0 0 0 0 0 0 SCIDRH W T8 0x0007 R R7 R6 R5 R4 R3 R2 R1 R0 SCIDRL W T7 T6 T5 T4 T3 T2 T1 T0 1.These registers are accessible if the AMAP bit in the SCISR2 register is set to zero. 2,These registers are accessible if the AMAP bit in the SCISR2 register is set to one. = Unimplemented or Reserved Figure 14-2. SCI Register Summary 1 Those registers are accessible if the AMAP bit in the SCISR2 register is set to zero 2 Those registers are accessible if the AMAP bit in the SCISR2 register is set to one S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 401 Serial Communication Interface (S12SCIV5) 14.3.2.1 SCI Baud Rate Registers (SCIBDH, SCIBDL) Module Base + 0x0000 R W Reset 7 IREN 0 6 TNP1 5 TNP0 4 SBR12 3 SBR11 2 SBR10 0 0 0 0 0 Figure 14-3. SCI Baud Rate Register (SCIBDH) 1 SBR9 0 0 SBR8 0 Module Base + 0x0001 R W Reset 7 SBR7 0 6 SBR6 5 SBR5 4 SBR4 3 SBR3 2 SBR2 0 0 0 0 0 Figure 14-4. SCI Baud Rate Register (SCIBDL) 1 SBR1 0 0 SBR0 0 Read: Anytime, if AMAP = 0. If only SCIBDH is written to, a read will not return the correct data until SCIBDL is written to as well, following a write to SCIBDH. Write: Anytime, if AMAP = 0. NOTE Those two registers are only visible in the memory map if AMAP = 0 (reset condition). The SCI baud rate register is used by to determine the baud rate of the SCI, and to control the infrared modulation/demodulation submodule. Table 14-2. SCIBDH and SCIBDL Field Descriptions Field Description 7 IREN Infrared Enable Bit — This bit enables/disables the infrared modulation/demodulation submodule. 0 IR disabled 1 IR enabled 6:5 Transmitter Narrow Pulse Bits — These bits enable whether the SCI transmits a 1/16, 3/16, 1/32 or 1/4 narrow TNP[1:0] pulse. See Table 14-3. 4:0 7:0 SBR[12:0] SCI Baud Rate Bits — The baud rate for the SCI is determined by the bits in this register. The baud rate is calculated two different ways depending on the state of the IREN bit. The formulas for calculating the baud rate are: When IREN = 0 then, SCI baud rate = SCI bus clock / (16 x SBR[12:0]) When IREN = 1 then, SCI baud rate = SCI bus clock / (32 x SBR[12:1]) Note: The baud rate generator is disabled after reset and not started until the TE bit or the RE bit is set for the first time. The baud rate generator is disabled when (SBR[12:0] = 0 and IREN = 0) or (SBR[12:1] = 0 and IREN = 1). Note: Writing to SCIBDH has no effect without writing to SCIBDL, because writing to SCIBDH puts the data in a temporary location until SCIBDL is written to. S12XS-Family Reference Manual, Rev. 1.03 402 PRELIMINARY Freescale Semiconductor Serial Communication Interface (S12SCIV5) Table 14-3. IRSCI Transmit Pulse Width TNP[1:0] 11 10 01 00 Narrow Pulse Width 1/4 1/32 1/16 3/16 14.3.2.2 SCI Control Register 1 (SCICR1) Module Base + 0x0002 7 6 5 4 3 2 1 0 R LOOPS SCISWAI RSRC M WAKE ILT PE PT W Reset 0 0 0 0 0 0 0 0 Figure 14-5. SCI Control Register 1 (SCICR1) Read: Anytime, if AMAP = 0. Write: Anytime, if AMAP = 0. NOTE This register is only visible in the memory map if AMAP = 0 (reset condition). Table 14-4. SCICR1 Field Descriptions Field Description 7 LOOPS 6 SCISWAI 5 RSRC 4 M 3 WAKE Loop Select Bit — LOOPS enables loop operation. In loop operation, the RXD pin is disconnected from the SCI and the transmitter output is internally connected to the receiver input. Both the transmitter and the receiver must be enabled to use the loop function. 0 Normal operation enabled 1 Loop operation enabled The receiver input is determined by the RSRC bit. SCI Stop in Wait Mode Bit — SCISWAI disables the SCI in wait mode. 0 SCI enabled in wait mode 1 SCI disabled in wait mode Receiver Source Bit — When LOOPS = 1, the RSRC bit determines the source for the receiver shift register input. See Table 14-5. 0 Receiver input internally connected to transmitter output 1 Receiver input connected externally to transmitter Data Format Mode Bit — MODE determines whether data characters are eight or nine bits long. 0 One start bit, eight data bits, one stop bit 1 One start bit, nine data bits, one stop bit Wakeup Condition Bit — WAKE determines which condition wakes up the SCI: a logic 1 (address mark) in the most significant bit position of a received data character or an idle condition on the RXD pin. 0 Idle line wakeup 1 Address mark wakeup S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 403 Serial Communication Interface (S12SCIV5) Table 14-4. SCICR1 Field Descriptions (continued) Field 2 ILT 1 PE 0 PT Description Idle Line Type Bit — ILT determines when the receiver starts counting logic 1s as idle character bits. The counting begins either after the start bit or after the stop bit. If the count begins after the start bit, then a string of logic 1s preceding the stop bit may cause false recognition of an idle character. Beginning the count after the stop bit avoids false idle character recognition, but requires properly synchronized transmissions. 0 Idle character bit count begins after start bit 1 Idle character bit count begins after stop bit Parity Enable Bit — PE enables the parity function. When enabled, the parity function inserts a parity bit in the most significant bit position. 0 Parity function disabled 1 Parity function enabled Parity Type Bit — PT determines whether the SCI generates and checks for even parity or odd parity. With even parity, an even number of 1s clears the parity bit and an odd number of 1s sets the parity bit. With odd parity, an odd number of 1s clears the parity bit and an even number of 1s sets the parity bit. 1 Even parity 1 Odd parity LOOPS 0 1 1 Table 14-5. Loop Functions RSRC x 0 1 Function Normal operation Loop mode with transmitter output internally connected to receiver input Single-wire mode with TXD pin connected to receiver input S12XS-Family Reference Manual, Rev. 1.03 404 PRELIMINARY Freescale Semiconductor Serial Communication Interface (S12SCIV5) 14.3.2.3 SCI Alternative Status Register 1 (SCIASR1) Module Base + 0x0000 7 6 5 4 R 0 0 0 RXEDGIF W Reset 0 0 0 0 = Unimplemented or Reserved 3 2 0 BERRV 0 0 Figure 14-6. SCI Alternative Status Register 1 (SCIASR1) 1 BERRIF 0 Read: Anytime, if AMAP = 1 Write: Anytime, if AMAP = 1 Table 14-6. SCIASR1 Field Descriptions 0 BKDIF 0 Field Description 7 RXEDGIF Receive Input Active Edge Interrupt Flag — RXEDGIF is asserted, if an active edge (falling if RXPOL = 0, rising if RXPOL = 1) on the RXD input occurs. RXEDGIF bit is cleared by writing a “1” to it. 0 No active receive on the receive input has occurred 1 An active edge on the receive input has occurred 2 BERRV Bit Error Value — BERRV reflects the state of the RXD input when the bit error detect circuitry is enabled and a mismatch to the expected value happened. The value is only meaningful, if BERRIF = 1. 0 A low input was sampled, when a high was expected 1 A high input reassembled, when a low was expected 1 BERRIF Bit Error Interrupt Flag — BERRIF is asserted, when the bit error detect circuitry is enabled and if the value sampled at the RXD input does not match the transmitted value. If the BERRIE interrupt enable bit is set an interrupt will be generated. The BERRIF bit is cleared by writing a “1” to it. 0 No mismatch detected 1 A mismatch has occurred 0 BKDIF Break Detect Interrupt Flag — BKDIF is asserted, if the break detect circuitry is enabled and a break signal is received. If the BKDIE interrupt enable bit is set an interrupt will be generated. The BKDIF bit is cleared by writing a “1” to it. 0 No break signal was received 1 A break signal was received S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 405 Serial Communication Interface (S12SCIV5) 14.3.2.4 SCI Alternative Control Register 1 (SCIACR1) Module Base + 0x0001 7 6 5 4 3 2 1 R 0 0 0 0 0 RXEDGIE BERRIE W Reset 0 0 0 0 0 0 0 = Unimplemented or Reserved Figure 14-7. SCI Alternative Control Register 1 (SCIACR1) Read: Anytime, if AMAP = 1 Write: Anytime, if AMAP = 1 Table 14-7. SCIACR1 Field Descriptions 0 BKDIE 0 Field Description 7 RSEDGIE Receive Input Active Edge Interrupt Enable — RXEDGIE enables the receive input active edge interrupt flag, RXEDGIF, to generate interrupt requests. 0 RXEDGIF interrupt requests disabled 1 RXEDGIF interrupt requests enabled 1 BERRIE Bit Error Interrupt Enable — BERRIE enables the bit error interrupt flag, BERRIF, to generate interrupt requests. 0 BERRIF interrupt requests disabled 1 BERRIF interrupt requests enabled 0 BKDIE Break Detect Interrupt Enable — BKDIE enables the break detect interrupt flag, BKDIF, to generate interrupt requests. 0 BKDIF interrupt requests disabled 1 BKDIF interrupt requests enabled S12XS-Family Reference Manual, Rev. 1.03 406 PRELIMINARY Freescale Semiconductor Serial Communication Interface (S12SCIV5) 14.3.2.5 SCI Alternative Control Register 2 (SCIACR2) Module Base + 0x0002 7 6 5 4 R 0 0 0 0 W Reset 0 0 0 0 = Unimplemented or Reserved 3 2 1 0 BERRM1 BERRM0 0 0 0 Figure 14-8. SCI Alternative Control Register 2 (SCIACR2) Read: Anytime, if AMAP = 1 Write: Anytime, if AMAP = 1 0 BKDFE 0 Table 14-8. SCIACR2 Field Descriptions Field Description 2:1 Bit Error Mode — Those two bits determines the functionality of the bit error detect feature. See Table 14-9. BERRM[1:0] 0 BKDFE Break Detect Feature Enable — BKDFE enables the break detect circuitry. 0 Break detect circuit disabled 1 Break detect circuit enabled BERRM1 0 0 1 1 Table 14-9. Bit Error Mode Coding BERRM0 Function 0 Bit error detect circuit is disabled 1 Receive input sampling occurs during the 9th time tick of a transmitted bit (refer to Figure 14-19) 0 Receive input sampling occurs during the 13th time tick of a transmitted bit (refer to Figure 14-19) 1 Reserved S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 407 Serial Communication Interface (S12SCIV5) 14.3.2.6 SCI Control Register 2 (SCICR2) Module Base + 0x0003 7 R TIE W Reset 0 Read: Anytime Write: Anytime 6 5 4 3 2 TCIE RIE ILIE TE RE 0 0 0 0 0 Figure 14-9. SCI Control Register 2 (SCICR2) Table 14-10. SCICR2 Field Descriptions 1 RWU 0 0 SBK 0 Field 7 TIE 6 TCIE 5 RIE 4 ILIE 3 TE 2 RE 1 RWU 0 SBK Description Transmitter Interrupt Enable Bit — TIE enables the transmit data register empty flag, TDRE, to generate interrupt requests. 0 TDRE interrupt requests disabled 1 TDRE interrupt requests enabled Transmission Complete Interrupt Enable Bit — TCIE enables the transmission complete flag, TC, to generate interrupt requests. 0 TC interrupt requests disabled 1 TC interrupt requests enabled Receiver Full Interrupt Enable Bit — RIE enables the receive data register full flag, RDRF, or the overrun flag, OR, to generate interrupt requests. 0 RDRF and OR interrupt requests disabled 1 RDRF and OR interrupt requests enabled Idle Line Interrupt Enable Bit — ILIE enables the idle line flag, IDLE, to generate interrupt requests. 0 IDLE interrupt requests disabled 1 IDLE interrupt requests enabled Transmitter Enable Bit — TE enables the SCI transmitter and configures the TXD pin as being controlled by the SCI. The TE bit can be used to queue an idle preamble. 0 Transmitter disabled 1 Transmitter enabled Receiver Enable Bit — RE enables the SCI receiver. 0 Receiver disabled 1 Receiver enabled Receiver Wakeup Bit — Standby state 0 Normal operation. 1 RWU enables the wakeup function and inhibits further receiver interrupt requests. Normally, hardware wakes the receiver by automatically clearing RWU. Send Break Bit — Toggling SBK sends one break character (10 or 11 logic 0s, respectively 13 or 14 logics 0s if BRK13 is set). Toggling implies clearing the SBK bit before the break character has finished transmitting. As long as SBK is set, the transmitter continues to send complete break characters (10 or 11 bits, respectively 13 or 14 bits). 0 No break characters 1 Transmit break characters S12XS-Family Reference Manual, Rev. 1.03 408 PRELIMINARY Freescale Semiconductor Serial Communication Interface (S12SCIV5) 14.3.2.7 SCI Status Register 1 (SCISR1) The SCISR1 and SCISR2 registers provides inputs to the MCU for generation of SCI interrupts. Also, these registers can be polled by the MCU to check the status of these bits. The flag-clearing procedures require that the status register be read followed by a read or write to the SCI data register.It is permissible to execute other instructions between the two steps as long as it does not compromise the handling of I/O, but the order of operations is important for flag clearing. Module Base + 0x0004 7 6 5 4 3 2 1 0 R TDRE TC RDRF IDLE OR NF FE PF W Reset 1 1 0 0 0 0 0 0 = Unimplemented or Reserved Figure 14-10. SCI Status Register 1 (SCISR1) Read: Anytime Write: Has no meaning or effect Table 14-11. SCISR1 Field Descriptions Field 7 TDRE 6 TC 5 RDRF 4 IDLE Description Transmit Data Register Empty Flag — TDRE is set when the transmit shift register receives a byte from the SCI data register. When TDRE is 1, the transmit data register (SCIDRH/L) is empty and can receive a new value to transmit.Clear TDRE by reading SCI status register 1 (SCISR1), with TDRE set and then writing to SCI data register low (SCIDRL). 0 No byte transferred to transmit shift register 1 Byte transferred to transmit shift register; transmit data register empty Transmit Complete Flag — TC is set low when there is a transmission in progress or when a preamble or break character is loaded. TC is set high when the TDRE flag is set and no data, preamble, or break character is being transmitted.When TC is set, the TXD pin becomes idle (logic 1). Clear TC by reading SCI status register 1 (SCISR1) with TC set and then writing to SCI data register low (SCIDRL). TC is cleared automatically when data, preamble, or break is queued and ready to be sent. TC is cleared in the event of a simultaneous set and clear of the TC flag (transmission not complete). 0 Transmission in progress 1 No transmission in progress Receive Data Register Full Flag — RDRF is set when the data in the receive shift register transfers to the SCI data register. Clear RDRF by reading SCI status register 1 (SCISR1) with RDRF set and then reading SCI data register low (SCIDRL). 0 Data not available in SCI data register 1 Received data available in SCI data register Idle Line Flag — IDLE is set when 10 consecutive logic 1s (if M = 0) or 11 consecutive logic 1s (if M =1) appear on the receiver input. Once the IDLE flag is cleared, a valid frame must again set the RDRF flag before an idle condition can set the IDLE flag.Clear IDLE by reading SCI status register 1 (SCISR1) with IDLE set and then reading SCI data register low (SCIDRL). 0 Receiver input is either active now or has never become active since the IDLE flag was last cleared 1 Receiver input has become idle Note: When the receiver wakeup bit (RWU) is set, an idle line condition does not set the IDLE flag. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 409 Serial Communication Interface (S12SCIV5) Table 14-11. SCISR1 Field Descriptions (continued) Field 3 OR 2 NF 1 FE 0 PF Description Overrun Flag — OR is set when software fails to read the SCI data register before the receive shift register receives the next frame. The OR bit is set immediately after the stop bit has been completely received for the second frame. The data in the shift register is lost, but the data already in the SCI data registers is not affected. Clear OR by reading SCI status register 1 (SCISR1) with OR set and then reading SCI data register low (SCIDRL). 0 No overrun 1 Overrun Note: OR flag may read back as set when RDRF flag is clear. This may happen if the following sequence of events occurs: 1. After the first frame is received, read status register SCISR1 (returns RDRF set and OR flag clear); 2. Receive second frame without reading the first frame in the data register (the second frame is not received and OR flag is set); 3. Read data register SCIDRL (returns first frame and clears RDRF flag in the status register); 4. Read status register SCISR1 (returns RDRF clear and OR set). Event 3 may be at exactly the same time as event 2 or any time after. When this happens, a dummy SCIDRL read following event 4 will be required to clear the OR flag if further frames are to be received. Noise Flag — NF is set when the SCI detects noise on the receiver input. NF bit is set during the same cycle as the RDRF flag but does not get set in the case of an overrun. Clear NF by reading SCI status register 1(SCISR1), and then reading SCI data register low (SCIDRL). 0 No noise 1 Noise Framing Error Flag — FE is set when a logic 0 is accepted as the stop bit. FE bit is set during the same cycle as the RDRF flag but does not get set in the case of an overrun. FE inhibits further data reception until it is cleared. Clear FE by reading SCI status register 1 (SCISR1) with FE set and then reading the SCI data register low (SCIDRL). 0 No framing error 1 Framing error Parity Error Flag — PF is set when the parity enable bit (PE) is set and the parity of the received data does not match the parity type bit (PT). PF bit is set during the same cycle as the RDRF flag but does not get set in the case of an overrun. Clear PF by reading SCI status register 1 (SCISR1), and then reading SCI data register low (SCIDRL). 0 No parity error 1 Parity error S12XS-Family Reference Manual, Rev. 1.03 410 PRELIMINARY Freescale Semiconductor Serial Communication Interface (S12SCIV5) 14.3.2.8 SCI Status Register 2 (SCISR2) Module Base + 0x0005 R W Reset 7 AMAP 0 6 5 4 0 0 TXPOL 0 0 0 = Unimplemented or Reserved 3 RXPOL 0 2 BRK13 0 1 TXDIR 0 0 RAF 0 Figure 14-11. SCI Status Register 2 (SCISR2) Read: Anytime Write: Anytime Table 14-12. SCISR2 Field Descriptions Field 7 AMAP 4 TXPOL 3 RXPOL 2 BRK13 1 TXDIR 0 RAF Description Alternative Map — This bit controls which registers sharing the same address space are accessible. In the reset condition the SCI behaves as previous versions. Setting AMAP=1 allows the access to another set of control and status registers and hides the baud rate and SCI control Register 1. 0 The registers labelled SCIBDH (0x0000),SCIBDL (0x0001), SCICR1 (0x0002) are accessible 1 The registers labelled SCIASR1 (0x0000),SCIACR1 (0x0001), SCIACR2 (0x00002) are accessible Transmit Polarity — This bit control the polarity of the transmitted data. In NRZ format, a one is represented by a mark and a zero is represented by a space for normal polarity, and the opposite for inverted polarity. In IrDA format, a zero is represented by short high pulse in the middle of a bit time remaining idle low for a one for normal polarity, and a zero is represented by short low pulse in the middle of a bit time remaining idle high for a one for inverted polarity. 0 Normal polarity 1 Inverted polarity Receive Polarity — This bit control the polarity of the received data. In NRZ format, a one is represented by a mark and a zero is represented by a space for normal polarity, and the opposite for inverted polarity. In IrDA format, a zero is represented by short high pulse in the middle of a bit time remaining idle low for a one for normal polarity, and a zero is represented by short low pulse in the middle of a bit time remaining idle high for a one for inverted polarity. 0 Normal polarity 1 Inverted polarity Break Transmit Character Length — This bit determines whether the transmit break character is 10 or 11 bit respectively 13 or 14 bits long. The detection of a framing error is not affected by this bit. 0 Break character is 10 or 11 bit long 1 Break character is 13 or 14 bit long Transmitter Pin Data Direction in Single-Wire Mode — This bit determines whether the TXD pin is going to be used as an input or output, in the single-wire mode of operation. This bit is only relevant in the single-wire mode of operation. 0 TXD pin to be used as an input in single-wire mode 1 TXD pin to be used as an output in single-wire mode Receiver Active Flag — RAF is set when the receiver detects a logic 0 during the RT1 time period of the start bit search. RAF is cleared when the receiver detects an idle character. 0 No reception in progress 1 Reception in progress S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 411 Serial Communication Interface (S12SCIV5) 14.3.2.9 SCI Data Registers (SCIDRH, SCIDRL) Module Base + 0x0006 7 6 5 4 3 2 1 0 R R8 0 0 0 0 0 0 T8 W Reset 0 0 0 0 0 0 0 0 = Unimplemented or Reserved Figure 14-12. SCI Data Registers (SCIDRH) Module Base + 0x0007 7 6 5 4 3 2 1 0 R R7 R6 R5 R4 R3 R2 R1 R0 W T7 T6 T5 T4 T3 T2 T1 T0 Reset 0 0 0 0 0 0 0 0 Figure 14-13. SCI Data Registers (SCIDRL) Read: Anytime; reading accesses SCI receive data register Write: Anytime; writing accesses SCI transmit data register; writing to R8 has no effect Table 14-13. SCIDRH and SCIDRL Field Descriptions Field SCIDRH 7 R8 SCIDRH 6 T8 SCIDRL 7:0 R[7:0] T[7:0] Description Received Bit 8 — R8 is the ninth data bit received when the SCI is configured for 9-bit data format (M = 1). Transmit Bit 8 — T8 is the ninth data bit transmitted when the SCI is configured for 9-bit data format (M = 1). R7:R0 — Received bits seven through zero for 9-bit or 8-bit data formats T7:T0 — Transmit bits seven through zero for 9-bit or 8-bit formats NOTE If the value of T8 is the same as in the previous transmission, T8 does not have to be rewritten.The same value is transmitted until T8 is rewritten In 8-bit data format, only SCI data register low (SCIDRL) needs to be accessed. When transmitting in 9-bit data format and using 8-bit write instructions, write first to SCI data register high (SCIDRH), then SCIDRL. S12XS-Family Reference Manual, Rev. 1.03 412 PRELIMINARY Freescale Semiconductor Serial Communication Interface (S12SCIV5) 14.4 Functional Description This section provides a complete functional description of the SCI block, detailing the operation of the design from the end user perspective in a number of subsections. Figure 14-14 shows the structure of the SCI module. The SCI allows full duplex, asynchronous, serial communication between the CPU and remote devices, including other CPUs. The SCI transmitter and receiver operate independently, although they use the same baud rate generator. The CPU monitors the status of the SCI, writes the data to be transmitted, and processes received data. R16XCLK RDRF/OR IREN SCI Data Register RXD Infrared Ir_RXD Receive Decoder SCRXD Receive Shift Register Receive and Wakeup Control RE RWU LOOPS RSRC Bus Clock Baud Rate Generator SBR12:SBR0 Data Format Control M WAKE ILT PE PT ÷16 Transmit Control Transmit T8 Shift Register SCI Data Register TE LOOPS SBK RSRC RXD R16XCLK R32XCLK SCTXD Infrared Transmit Encoder Ir_TXD R8 NF FE PF RAF ILIE IDLE RDRF OR RIE TIE IDLE TDRE TC TCIE TDRE TC RXEDGIE Active Edge RXEDGIF Detect BKDIF Break Detect BKDIE BKDFE LIN Transmit BERRIF Collision Detect BERRIE BERRM[1:0] TXD TNP[1:0] IREN Figure 14-14. Detailed SCI Block Diagram SCI Interrupt Request S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 413 Serial Communication Interface (S12SCIV5) 14.4.1 Infrared Interface Submodule This module provides the capability of transmitting narrow pulses to an IR LED and receiving narrow pulses and transforming them to serial bits, which are sent to the SCI. The IrDA physical layer specification defines a half-duplex infrared communication link for exchange data. The full standard includes data rates up to 16 Mbits/s. This design covers only data rates between 2.4 Kbits/s and 115.2 Kbits/s. The infrared submodule consists of two major blocks: the transmit encoder and the receive decoder. The SCI transmits serial bits of data which are encoded by the infrared submodule to transmit a narrow pulse for every zero bit. No pulse is transmitted for every one bit. When receiving data, the IR pulses should be detected using an IR photo diode and transformed to CMOS levels by the IR receive decoder (external from the MCU). The narrow pulses are then stretched by the infrared submodule to get back to a serial bit stream to be received by the SCI.The polarity of transmitted pulses and expected receive pulses can be inverted so that a direct connection can be made to external IrDA transceiver modules that uses active low pulses. The infrared submodule receives its clock sources from the SCI. One of these two clocks are selected in the infrared submodule in order to generate either 3/16, 1/16, 1/32 or 1/4 narrow pulses during transmission. The infrared block receives two clock sources from the SCI, R16XCLK and R32XCLK, which are configured to generate the narrow pulse width during transmission. The R16XCLK and R32XCLK are internal clocks with frequencies 16 and 32 times the baud rate respectively. Both R16XCLK and R32XCLK clocks are used for transmitting data. The receive decoder uses only the R16XCLK clock. 14.4.1.1 Infrared Transmit Encoder The infrared transmit encoder converts serial bits of data from transmit shift register to the TXD pin. A narrow pulse is transmitted for a zero bit and no pulse for a one bit. The narrow pulse is sent in the middle of the bit with a duration of 1/32, 1/16, 3/16 or 1/4 of a bit time. A narrow high pulse is transmitted for a zero bit when TXPOL is cleared, while a narrow low pulse is transmitted for a zero bit when TXPOL is set. 14.4.1.2 Infrared Receive Decoder The infrared receive block converts data from the RXD pin to the receive shift register. A narrow pulse is expected for each zero received and no pulse is expected for each one received. A narrow high pulse is expected for a zero bit when RXPOL is cleared, while a narrow low pulse is expected for a zero bit when RXPOL is set. This receive decoder meets the edge jitter requirement as defined by the IrDA serial infrared physical layer specification. 14.4.2 LIN Support This module provides some basic support for the LIN protocol. At first this is a break detect circuitry making it easier for the LIN software to distinguish a break character from an incoming data stream. As a further addition is supports a collision detection at the bit level as well as cancelling pending transmissions. S12XS-Family Reference Manual, Rev. 1.03 414 PRELIMINARY Freescale Semiconductor Serial Communication Interface (S12SCIV5) 14.4.3 Data Format The SCI uses the standard NRZ mark/space data format. When Infrared is enabled, the SCI uses RZI data format where zeroes are represented by light pulses and ones remain low. See Figure 14-15 below. Start Bit Bit 0 Bit 1 Bit 2 8-Bit Data Format (Bit M in SCICR1 Clear) Possible Parity Bit Bit 3 Bit 4 Bit 5 Bit 6 Bit 7 STOP Bit Next Start Bit Standard SCI Data Infrared SCI Data Start Bit Bit 0 Bit 1 Bit 2 9-Bit Data Format (Bit M in SCICR1 Set) Bit 3 Bit 4 Bit 5 Bit 6 POSSIBLE PARITY Bit Bit 7 Bit 8 STOP Bit NEXT START Bit Standard SCI Data Figure 14-15. SCI Data Formats Infrared SCI Data Each data character is contained in a frame that includes a start bit, eight or nine data bits, and a stop bit. Clearing the M bit in SCI control register 1 configures the SCI for 8-bit data characters. A frame with eight data bits has a total of 10 bits. Setting the M bit configures the SCI for nine-bit data characters. A frame with nine data bits has a total of 11 bits. Table 14-14. Example of 8-Bit Data Formats Start Bit Data Bits Address Bits Parity Bits Stop Bit 1 8 0 0 1 1 7 0 1 1 1 7 11 0 1 1 The address bit identifies the frame as an address character. See Section 14.4.6.6, “Receiver Wakeup”. When the SCI is configured for 9-bit data characters, the ninth data bit is the T8 bit in SCI data register high (SCIDRH). It remains unchanged after transmission and can be used repeatedly without rewriting it. A frame with nine data bits has a total of 11 bits. Table 14-15. Example of 9-Bit Data Formats Start Bit 1 1 1 Data Bits 9 8 8 Address Bits 0 0 11 Parity Bits 0 1 0 Stop Bit 1 1 1 S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 415 Serial Communication Interface (S12SCIV5) 1 The address bit identifies the frame as an address character. See Section 14.4.6.6, “Receiver Wakeup”. 14.4.4 Baud Rate Generation A 13-bit modulus counter in the baud rate generator derives the baud rate for both the receiver and the transmitter. The value from 0 to 8191 written to the SBR12:SBR0 bits determines the bus clock divisor. The SBR bits are in the SCI baud rate registers (SCIBDH and SCIBDL). The baud rate clock is synchronized with the bus clock and drives the receiver. The baud rate clock divided by 16 drives the transmitter. The receiver has an acquisition rate of 16 samples per bit time. Baud rate generation is subject to one source of error: • Integer division of the bus clock may not give the exact target frequency. Table 14-16 lists some examples of achieving target baud rates with a bus clock frequency of 25 MHz. When IREN = 0 then, SCI baud rate = SCI bus clock / (16 * SCIBR[12:0]) Table 14-16. Baud Rates (Example: Bus Clock = 25 MHz) Bits SBR[12:0] 41 81 163 326 651 1302 2604 5208 Receiver Clock (Hz) 609,756.1 308,642.0 153,374.2 76,687.1 38,402.5 19,201.2 9600.6 4800.0 Transmitter Clock (Hz) 38,109.8 19,290.1 9585.9 4792.9 2400.2 1200.1 600.0 300.0 Target Baud Rate 38,400 19,200 9,600 4,800 2,400 1,200 600 300 Error (%) .76 .47 .16 .15 .01 .01 .00 .00 S12XS-Family Reference Manual, Rev. 1.03 416 PRELIMINARY Freescale Semiconductor 14.4.5 Transmitter Serial Communication Interface (S12SCIV5) Internal Bus Bus Clock Baud Divider ÷ 16 SCI Data Registers SBR12:SBR0 Stop 11-Bit Transmit Register M H8 7 6 5 4 3 2 1 0 L Start TXPOL SCTXD MSB PE PT TDRE IRQ TC IRQ T8 Parity Generation TIE TDRE TC TCIE Load from SCIDR Shift Enable Preamble (All 1s) Break (All 0s) LOOP CONTROL To Receiver LOOPS RSRC Transmitter Control TE SBK BERRM[1:0] BER IRQ BERRIF TCIE Transmit Collision Detect Figure 14-16. Transmitter Block Diagram SCTXD SCRXD (From Receiver) 14.4.5.1 Transmitter Character Length The SCI transmitter can accommodate either 8-bit or 9-bit data characters. The state of the M bit in SCI control register 1 (SCICR1) determines the length of data characters. When transmitting 9-bit data, bit T8 in SCI data register high (SCIDRH) is the ninth bit (bit 8). 14.4.5.2 Character Transmission To transmit data, the MCU writes the data bits to the SCI data registers (SCIDRH/SCIDRL), which in turn are transferred to the transmitter shift register. The transmit shift register then shifts a frame out through the TXD pin, after it has prefaced them with a start bit and appended them with a stop bit. The SCI data registers (SCIDRH and SCIDRL) are the write-only buffers between the internal data bus and the transmit shift register. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 417 Serial Communication Interface (S12SCIV5) The SCI also sets a flag, the transmit data register empty flag (TDRE), every time it transfers data from the buffer (SCIDRH/L) to the transmitter shift register.The transmit driver routine may respond to this flag by writing another byte to the Transmitter buffer (SCIDRH/SCIDRL), while the shift register is still shifting out the first byte. To initiate an SCI transmission: 1. Configure the SCI: a) Select a baud rate. Write this value to the SCI baud registers (SCIBDH/L) to begin the baud rate generator. Remember that the baud rate generator is disabled when the baud rate is zero. Writing to the SCIBDH has no effect without also writing to SCIBDL. b) Write to SCICR1 to configure word length, parity, and other configuration bits (LOOPS,RSRC,M,WAKE,ILT,PE,PT). c) Enable the transmitter, interrupts, receive, and wake up as required, by writing to the SCICR2 register bits (TIE,TCIE,RIE,ILIE,TE,RE,RWU,SBK). A preamble or idle character will now be shifted out of the transmitter shift register. 2. Transmit Procedure for each byte: a) Poll the TDRE flag by reading the SCISR1 or responding to the TDRE interrupt. Keep in mind that the TDRE bit resets to one. b) If the TDRE flag is set, write the data to be transmitted to SCIDRH/L, where the ninth bit is written to the T8 bit in SCIDRH if the SCI is in 9-bit data format. A new transmission will not result until the TDRE flag has been cleared. 3. Repeat step 2 for each subsequent transmission. NOTE The TDRE flag is set when the shift register is loaded with the next data to be transmitted from SCIDRH/L, which happens, generally speaking, a little over half-way through the stop bit of the previous frame. Specifically, this transfer occurs 9/16ths of a bit time AFTER the start of the stop bit of the previous frame. Writing the TE bit from 0 to a 1 automatically loads the transmit shift register with a preamble of 10 logic 1s (if M = 0) or 11 logic 1s (if M = 1). After the preamble shifts out, control logic transfers the data from the SCI data register into the transmit shift register. A logic 0 start bit automatically goes into the least significant bit position of the transmit shift register. A logic 1 stop bit goes into the most significant bit position. Hardware supports odd or even parity. When parity is enabled, the most significant bit (MSB) of the data character is the parity bit. The transmit data register empty flag, TDRE, in SCI status register 1 (SCISR1) becomes set when the SCI data register transfers a byte to the transmit shift register. The TDRE flag indicates that the SCI data register can accept new data from the internal data bus. If the transmit interrupt enable bit, TIE, in SCI control register 2 (SCICR2) is also set, the TDRE flag generates a transmitter interrupt request. S12XS-Family Reference Manual, Rev. 1.03 418 PRELIMINARY Freescale Semiconductor Serial Communication Interface (S12SCIV5) When the transmit shift register is not transmitting a frame, the TXD pin goes to the idle condition, logic 1. If at any time software clears the TE bit in SCI control register 2 (SCICR2), the transmitter enable signal goes low and the transmit signal goes idle. If software clears TE while a transmission is in progress (TC = 0), the frame in the transmit shift register continues to shift out. To avoid accidentally cutting off the last frame in a message, always wait for TDRE to go high after the last frame before clearing TE. To separate messages with preambles with minimum idle line time, use this sequence between messages: 1. Write the last byte of the first message to SCIDRH/L. 2. Wait for the TDRE flag to go high, indicating the transfer of the last frame to the transmit shift register. 3. Queue a preamble by clearing and then setting the TE bit. 4. Write the first byte of the second message to SCIDRH/L. 14.4.5.3 Break Characters Writing a logic 1 to the send break bit, SBK, in SCI control register 2 (SCICR2) loads the transmit shift register with a break character. A break character contains all logic 0s and has no start, stop, or parity bit. Break character length depends on the M bit in SCI control register 1 (SCICR1). As long as SBK is at logic 1, transmitter logic continuously loads break characters into the transmit shift register. After software clears the SBK bit, the shift register finishes transmitting the last break character and then transmits at least one logic 1. The automatic logic 1 at the end of a break character guarantees the recognition of the start bit of the next frame. The SCI recognizes a break character when there are 10 or 11(M = 0 or M = 1) consecutive zero received. Depending if the break detect feature is enabled or not receiving a break character has these effects on SCI registers. If the break detect feature is disabled (BKDFE = 0): • Sets the framing error flag, FE • Sets the receive data register full flag, RDRF • Clears the SCI data registers (SCIDRH/L) • May set the overrun flag, OR, noise flag, NF, parity error flag, PE, or the receiver active flag, RAF (see 3.4.4 and 3.4.5 SCI Status Register 1 and 2) If the break detect feature is enabled (BKDFE = 1) there are two scenarios1 The break is detected right from a start bit or is detected during a byte reception. • Sets the break detect interrupt flag, BLDIF • Does not change the data register full flag, RDRF or overrun flag OR • Does not change the framing error flag FE, parity error flag PE. • Does not clear the SCI data registers (SCIDRH/L) • May set noise flag NF, or receiver active flag RAF. 1. A Break character in this context are either 10 or 11 consecutive zero received bits S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 419 Serial Communication Interface (S12SCIV5) Figure 14-17 shows two cases of break detect. In trace RXD_1 the break symbol starts with the start bit, while in RXD_2 the break starts in the middle of a transmission. If BRKDFE = 1, in RXD_1 case there will be no byte transferred to the receive buffer and the RDRF flag will not be modified. Also no framing error or parity error will be flagged from this transfer. In RXD_2 case, however the break signal starts later during the transmission. At the expected stop bit position the byte received so far will be transferred to the receive buffer, the receive data register full flag will be set, a framing error and if enabled and appropriate a parity error will be set. Once the break is detected the BRKDIF flag will be set. Start Bit Position Stop Bit Position BRKDIF = 1 RXD_1 Zero Bit Counter 1 2 3 4 5 6 7 8 9 10 . . . FE = 1 BRKDIF = 1 RXD_2 Zero Bit Counter 1 2 3 4 5 6 7 8 9 10 . . . Figure 14-17. Break Detection if BRKDFE = 1 (M = 0) 14.4.5.4 Idle Characters An idle character (or preamble) contains all logic 1s and has no start, stop, or parity bit. Idle character length depends on the M bit in SCI control register 1 (SCICR1). The preamble is a synchronizing idle character that begins the first transmission initiated after writing the TE bit from 0 to 1. If the TE bit is cleared during a transmission, the TXD pin becomes idle after completion of the transmission in progress. Clearing and then setting the TE bit during a transmission queues an idle character to be sent after the frame currently being transmitted. NOTE When queueing an idle character, return the TE bit to logic 1 before the stop bit of the current frame shifts out through the TXD pin. Setting TE after the stop bit appears on TXD causes data previously written to the SCI data register to be lost. Toggle the TE bit for a queued idle character while the TDRE flag is set and immediately before writing the next byte to the SCI data register. If the TE bit is clear and the transmission is complete, the SCI is not the master of the TXD pin S12XS-Family Reference Manual, Rev. 1.03 420 PRELIMINARY Freescale Semiconductor 14.4.5.5 LIN Transmit Collision Detection This module allows to check for collisions on the LIN bus. Receive Shift Register Synchronizer Stage Bit Error Compare Bus Clock RXD Pin Serial Communication Interface (S12SCIV5) LIN Physical Interface LIN Bus Sample Point Transmit Shift Register TXD Pin Figure 14-18. Collision Detect Principle If the bit error circuit is enabled (BERRM[1:0] = 0:1 or = 1:0]), the error detect circuit will compare the transmitted and the received data stream at a point in time and flag any mismatch. The timing checks run when transmitter is active (not idle). As soon as a mismatch between the transmitted data and the received data is detected the following happens: • The next bit transmitted will have a high level (TXPOL = 0) or low level (TXPOL = 1) • The transmission is aborted and the byte in transmit buffer is discarded. • the transmit data register empty and the transmission complete flag will be set • The bit error interrupt flag, BERRIF, will be set. • No further transmissions will take place until the BERRIF is cleared. Output Transmit Shift Register 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 0 Sampling Begin Sampling End Sampling Begin Sampling End Input Receive Shift Register BERRM[1:0] = 0:1 BERRM[1:0] = 1:1 Compare Sample Points Figure 14-19. Timing Diagram Bit Error Detection If the bit error detect feature is disabled, the bit error interrupt flag is cleared. NOTE The RXPOL and TXPOL bit should be set the same when transmission collision detect feature is enabled, otherwise the bit error interrupt flag may be set incorrectly. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 421 Serial Communication Interface (S12SCIV5) 14.4.6 Receiver Internal Bus SBR12:SBR0 SCI Data Register SCRXD From TXD Pin or Transmitter Bus Clock RXPOL Loop Control LOOPS RSRC Baud Divider Data Recovery RE RAF M WAKE ILT PE PT Wakeup Logic Parity Checking BRKDFE Break Detect Logic MSB Stop 11-Bit Receive Shift Register H8 7 6 5 4 3 2 1 0 L All 1s RDRF OR BRKDIF BRKDIE FE NF RWU PE R8 IDLE ILIE Idle IRQ RDRF/OR IRQ RIE Break IRQ Start Active Edge Detect Logic RXEDGIF RXEDGIE Figure 14-20. SCI Receiver Block Diagram RX Active Edge IRQ 14.4.6.1 Receiver Character Length The SCI receiver can accommodate either 8-bit or 9-bit data characters. The state of the M bit in SCI control register 1 (SCICR1) determines the length of data characters. When receiving 9-bit data, bit R8 in SCI data register high (SCIDRH) is the ninth bit (bit 8). 14.4.6.2 Character Reception During an SCI reception, the receive shift register shifts a frame in from the RXD pin. The SCI data register is the read-only buffer between the internal data bus and the receive shift register. After a complete frame shifts into the receive shift register, the data portion of the frame transfers to the SCI data register. The receive data register full flag, RDRF, in SCI status register 1 (SCISR1) becomes set, S12XS-Family Reference Manual, Rev. 1.03 422 PRELIMINARY Freescale Semiconductor Serial Communication Interface (S12SCIV5) indicating that the received byte can be read. If the receive interrupt enable bit, RIE, in SCI control register 2 (SCICR2) is also set, the RDRF flag generates an RDRF interrupt request. 14.4.6.3 Data Sampling The RT clock rate. The RT clock is an internal signal with a frequency 16 times the baud rate. To adjust for baud rate mismatch, the RT clock (see Figure 14-21) is re-synchronized: • After every start bit • After the receiver detects a data bit change from logic 1 to logic 0 (after the majority of data bit samples at RT8, RT9, and RT10 returns a valid logic 1 and the majority of the next RT8, RT9, and RT10 samples returns a valid logic 0) To locate the start bit, data recovery logic does an asynchronous search for a logic 0 preceded by three logic 1s.When the falling edge of a possible start bit occurs, the RT clock begins to count to 16. Start Bit LSB RXD Samples 1 1 1 1 1 1 1 1 0 0 0 0000 RT1 RT1 RT1 RT1 RT1 RT1 RT1 RT1 RT1 RT2 RT3 RT4 RT5 RT6 RT7 RT8 RT9 RT10 RT11 RT12 RT13 RT14 RT15 RT16 RT1 RT2 RT3 RT4 Start Bit Qualification Start Bit Verification Data Sampling RT Clock RT CLock Count Reset RT Clock Figure 14-21. Receiver Data Sampling To verify the start bit and to detect noise, data recovery logic takes samples at RT3, RT5, and RT7. Figure 14-17 summarizes the results of the start bit verification samples. Table 14-17. Start Bit Verification RT3, RT5, and RT7 Samples 000 001 010 011 100 101 110 111 Start Bit Verification Yes Yes Yes No Yes No No No Noise Flag 0 1 1 0 1 0 0 0 If start bit verification is not successful, the RT clock is reset and a new search for a start bit begins. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 423 Serial Communication Interface (S12SCIV5) To determine the value of a data bit and to detect noise, recovery logic takes samples at RT8, RT9, and RT10. Table 14-18 summarizes the results of the data bit samples. Table 14-18. Data Bit Recovery RT8, RT9, and RT10 Samples 000 001 010 011 100 101 110 111 Data Bit Determination 0 0 0 1 0 1 1 1 Noise Flag 0 1 1 1 1 1 1 0 NOTE The RT8, RT9, and RT10 samples do not affect start bit verification. If any or all of the RT8, RT9, and RT10 start bit samples are logic 1s following a successful start bit verification, the noise flag (NF) is set and the receiver assumes that the bit is a start bit (logic 0). To verify a stop bit and to detect noise, recovery logic takes samples at RT8, RT9, and RT10. Table 14-19 summarizes the results of the stop bit samples. Table 14-19. Stop Bit Recovery RT8, RT9, and RT10 Samples 000 001 010 011 100 101 110 111 Framing Error Flag 1 1 1 0 1 0 0 0 Noise Flag 0 1 1 1 1 1 1 0 S12XS-Family Reference Manual, Rev. 1.03 424 PRELIMINARY Freescale Semiconductor Serial Communication Interface (S12SCIV5) In Figure 14-22 the verification samples RT3 and RT5 determine that the first low detected was noise and not the beginning of a start bit. The RT clock is reset and the start bit search begins again. The noise flag is not set because the noise occurred before the start bit was found. Start Bit LSB RXD Samples 1 1 1 0 1 110 0 0 0000 RT Clock RT1 RT1 RT1 RT1 RT2 RT3 RT4 RT5 RT1 RT1 RT2 RT3 RT4 RT5 RT6 RT7 RT8 RT9 RT10 RT11 RT12 RT13 RT14 RT15 RT16 RT1 RT2 RT3 RT Clock Count Reset RT Clock Figure 14-22. Start Bit Search Example 1 In Figure 14-23, verification sample at RT3 is high. The RT3 sample sets the noise flag. Although the perceived bit time is misaligned, the data samples RT8, RT9, and RT10 are within the bit time and data recovery is successful. Perceived Start Bit Actual Start Bit LSB RXD Samples 1 1 1 1 1 0 1 0 0000 RT1 RT1 RT1 RT1 RT1 RT1 RT2 RT3 RT4 RT5 RT6 RT7 RT8 RT9 RT10 RT11 RT12 RT13 RT14 RT15 RT16 RT1 RT2 RT3 RT4 RT5 RT6 RT7 RT Clock RT Clock Count Reset RT Clock Figure 14-23. Start Bit Search Example 2 S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 425 Serial Communication Interface (S12SCIV5) In Figure 14-24, a large burst of noise is perceived as the beginning of a start bit, although the test sample at RT5 is high. The RT5 sample sets the noise flag. Although this is a worst-case misalignment of perceived bit time, the data samples RT8, RT9, and RT10 are within the bit time and data recovery is successful. Perceived Start Bit Actual Start Bit LSB RXD Samples 1 1 1 0 0 1 0000 RT Clock RT1 RT1 RT1 RT1 RT2 RT3 RT4 RT5 RT6 RT7 RT8 RT9 RT10 RT11 RT12 RT13 RT14 RT15 RT16 RT1 RT2 RT3 RT4 RT5 RT6 RT7 RT8 RT9 RT Clock Count Reset RT Clock Figure 14-24. Start Bit Search Example 3 Figure 14-25 shows the effect of noise early in the start bit time. Although this noise does not affect proper synchronization with the start bit time, it does set the noise flag. Perceived and Actual Start Bit LSB RXD Samples 1 1 1 1 1 1 1 1 1 0 1 0 RT1 RT1 RT1 RT1 RT1 RT1 RT1 RT1 RT1 RT1 RT2 RT3 RT4 RT5 RT6 RT7 RT8 RT9 RT10 RT11 RT12 RT13 RT14 RT15 RT16 RT1 RT2 RT3 RT Clock RT Clock Count Reset RT Clock Figure 14-25. Start Bit Search Example 4 S12XS-Family Reference Manual, Rev. 1.03 426 PRELIMINARY Freescale Semiconductor Serial Communication Interface (S12SCIV5) Figure 14-26 shows a burst of noise near the beginning of the start bit that resets the RT clock. The sample after the reset is low but is not preceded by three high samples that would qualify as a falling edge. Depending on the timing of the start bit search and on the data, the frame may be missed entirely or it may set the framing error flag. RXD Start Bit LSB No Start Bit Found Samples 1 1 1 1 1 1 1 1 1 0 0 1 100000000 RT Clock RT1 RT1 RT1 RT1 RT1 RT1 RT1 RT1 RT1 RT1 RT1 RT1 RT7 RT6 RT5 RT4 RT3 RT2 RT1 RT1 RT1 RT1 RT1 RT1 RT1 RT1 RT1 RT1 RT Clock Count Reset RT Clock Figure 14-26. Start Bit Search Example 5 In Figure 14-27, a noise burst makes the majority of data samples RT8, RT9, and RT10 high. This sets the noise flag but does not reset the RT clock. In start bits only, the RT8, RT9, and RT10 data samples are ignored. Start Bit LSB RXD Samples 1 1 1 1 1 1 1 1 1 0 0 0 0101 RT3 RT2 RT1 RT16 RT15 RT14 RT13 RT12 RT11 RT10 RT Clock RT Clock Count Reset RT Clock RT1 RT1 RT1 RT1 RT1 RT1 RT1 RT1 RT1 RT1 RT2 RT3 Figure 14-27. Start Bit Search Example 6 RT4 RT5 RT6 RT7 RT8 RT9 14.4.6.4 Framing Errors If the data recovery logic does not detect a logic 1 where the stop bit should be in an incoming frame, it sets the framing error flag, FE, in SCI status register 1 (SCISR1). A break character also sets the FE flag because a break character has no stop bit. The FE flag is set at the same time that the RDRF flag is set. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 427 Serial Communication Interface (S12SCIV5) 14.4.6.5 Baud Rate Tolerance A transmitting device may be operating at a baud rate below or above the receiver baud rate. Accumulated bit time misalignment can cause one of the three stop bit data samples (RT8, RT9, and RT10) to fall outside the actual stop bit. A noise error will occur if the RT8, RT9, and RT10 samples are not all the same logical values. A framing error will occur if the receiver clock is misaligned in such a way that the majority of the RT8, RT9, and RT10 stop bit samples are a logic zero. As the receiver samples an incoming frame, it re-synchronizes the RT clock on any valid falling edge within the frame. Re synchronization within frames will correct a misalignment between transmitter bit times and receiver bit times. 14.4.6.5.1 Slow Data Tolerance Figure 14-28 shows how much a slow received frame can be misaligned without causing a noise error or a framing error. The slow stop bit begins at RT8 instead of RT1 but arrives in time for the stop bit data samples at RT8, RT9, and RT10. MSB Stop Receiver RT Clock RT1 RT2 RT3 RT4 RT5 RT6 RT7 RT8 RT9 RT10 RT11 RT12 RT13 RT14 RT15 RT16 Data Samples Figure 14-28. Slow Data Let’s take RTr as receiver RT clock and RTt as transmitter RT clock. For an 8-bit data character, it takes the receiver 9 bit times x 16 RTr cycles +7 RTr cycles = 151 RTr cycles to start data sampling of the stop bit. With the misaligned character shown in Figure 14-28, the receiver counts 151 RTr cycles at the point when the count of the transmitting device is 9 bit times x 16 RTt cycles = 144 RTt cycles. The maximum percent difference between the receiver count and the transmitter count of a slow 8-bit data character with no errors is: ((151 – 144) / 151) x 100 = 4.63% For a 9-bit data character, it takes the receiver 10 bit times x 16 RTr cycles + 7 RTr cycles = 167 RTr cycles to start data sampling of the stop bit. With the misaligned character shown in Figure 14-28, the receiver counts 167 RTr cycles at the point when the count of the transmitting device is 10 bit times x 16 RTt cycles = 160 RTt cycles. The maximum percent difference between the receiver count and the transmitter count of a slow 9-bit character with no errors is: ((167 – 160) / 167) X 100 = 4.19% S12XS-Family Reference Manual, Rev. 1.03 428 PRELIMINARY Freescale Semiconductor Serial Communication Interface (S12SCIV5) 14.4.6.5.2 Fast Data Tolerance Figure 14-29 shows how much a fast received frame can be misaligned. The fast stop bit ends at RT10 instead of RT16 but is still sampled at RT8, RT9, and RT10. Stop Idle or Next Frame Receiver RT Clock RT1 RT2 RT3 RT4 RT5 RT6 RT7 RT8 RT9 RT10 RT11 RT12 RT13 RT14 RT15 RT16 Data Samples Figure 14-29. Fast Data For an 8-bit data character, it takes the receiver 9 bit times x 16 RTr cycles + 10 RTr cycles = 154 RTr cycles to finish data sampling of the stop bit. With the misaligned character shown in Figure 14-29, the receiver counts 154 RTr cycles at the point when the count of the transmitting device is 10 bit times x 16 RTt cycles = 160 RTt cycles. The maximum percent difference between the receiver count and the transmitter count of a fast 8-bit character with no errors is: ((160 – 154) / 160) x 100 = 3.75% For a 9-bit data character, it takes the receiver 10 bit times x 16 RTr cycles + 10 RTr cycles = 170 RTr cycles to finish data sampling of the stop bit. With the misaligned character shown in Figure 14-29, the receiver counts 170 RTr cycles at the point when the count of the transmitting device is 11 bit times x 16 RTt cycles = 176 RTt cycles. The maximum percent difference between the receiver count and the transmitter count of a fast 9-bit character with no errors is: ((176 – 170) /176) x 100 = 3.40% 14.4.6.6 Receiver Wakeup To enable the SCI to ignore transmissions intended only for other receivers in multiple-receiver systems, the receiver can be put into a standby state. Setting the receiver wakeup bit, RWU, in SCI control register 2 (SCICR2) puts the receiver into standby state during which receiver interrupts are disabled.The SCI will still load the receive data into the SCIDRH/L registers, but it will not set the RDRF flag. The transmitting device can address messages to selected receivers by including addressing information in the initial frame or frames of each message. The WAKE bit in SCI control register 1 (SCICR1) determines how the SCI is brought out of the standby state to process an incoming message. The WAKE bit enables either idle line wakeup or address mark wakeup. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 429 Serial Communication Interface (S12SCIV5) 14.4.6.6.1 Idle Input line Wakeup (WAKE = 0) In this wakeup method, an idle condition on the RXD pin clears the RWU bit and wakes up the SCI. The initial frame or frames of every message contain addressing information. All receivers evaluate the addressing information, and receivers for which the message is addressed process the frames that follow. Any receiver for which a message is not addressed can set its RWU bit and return to the standby state. The RWU bit remains set and the receiver remains on standby until another idle character appears on the RXD pin. Idle line wakeup requires that messages be separated by at least one idle character and that no message contains idle characters. The idle character that wakes a receiver does not set the receiver idle bit, IDLE, or the receive data register full flag, RDRF. The idle line type bit, ILT, determines whether the receiver begins counting logic 1s as idle character bits after the start bit or after the stop bit. ILT is in SCI control register 1 (SCICR1). 14.4.6.6.2 Address Mark Wakeup (WAKE = 1) In this wakeup method, a logic 1 in the most significant bit (MSB) position of a frame clears the RWU bit and wakes up the SCI. The logic 1 in the MSB position marks a frame as an address frame that contains addressing information. All receivers evaluate the addressing information, and the receivers for which the message is addressed process the frames that follow.Any receiver for which a message is not addressed can set its RWU bit and return to the standby state. The RWU bit remains set and the receiver remains on standby until another address frame appears on the RXD pin. The logic 1 MSB of an address frame clears the receiver’s RWU bit before the stop bit is received and sets the RDRF flag. Address mark wakeup allows messages to contain idle characters but requires that the MSB be reserved for use in address frames. NOTE With the WAKE bit clear, setting the RWU bit after the RXD pin has been idle can cause the receiver to wake up immediately. 14.4.7 Single-Wire Operation Normally, the SCI uses two pins for transmitting and receiving. In single-wire operation, the RXD pin is disconnected from the SCI. The SCI uses the TXD pin for both receiving and transmitting. Transmitter TXD Receiver RXD Figure 14-30. Single-Wire Operation (LOOPS = 1, RSRC = 1) S12XS-Family Reference Manual, Rev. 1.03 430 PRELIMINARY Freescale Semiconductor Serial Communication Interface (S12SCIV5) Enable single-wire operation by setting the LOOPS bit and the receiver source bit, RSRC, in SCI control register 1 (SCICR1). Setting the LOOPS bit disables the path from the RXD pin to the receiver. Setting the RSRC bit connects the TXD pin to the receiver. Both the transmitter and receiver must be enabled (TE = 1 and RE = 1).The TXDIR bit (SCISR2[1]) determines whether the TXD pin is going to be used as an input (TXDIR = 0) or an output (TXDIR = 1) in this mode of operation. NOTE In single-wire operation data from the TXD pin is inverted if RXPOL is set. 14.4.8 Loop Operation In loop operation the transmitter output goes to the receiver input. The RXD pin is disconnected from the SCI. Transmitter TXD Receiver RXD Figure 14-31. Loop Operation (LOOPS = 1, RSRC = 0) Enable loop operation by setting the LOOPS bit and clearing the RSRC bit in SCI control register 1 (SCICR1). Setting the LOOPS bit disables the path from the RXD pin to the receiver. Clearing the RSRC bit connects the transmitter output to the receiver input. Both the transmitter and receiver must be enabled (TE = 1 and RE = 1). NOTE In loop operation data from the transmitter is not recognized by the receiver if RXPOL and TXPOL are not the same. 14.5 Initialization/Application Information 14.5.1 Reset Initialization See Section 14.3.2, “Register Descriptions”. 14.5.2 Modes of Operation 14.5.2.1 Run Mode Normal mode of operation. To initialize a SCI transmission, see Section 14.4.5.2, “Character Transmission”. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 431 Serial Communication Interface (S12SCIV5) 14.5.2.2 Wait Mode SCI operation in wait mode depends on the state of the SCISWAI bit in the SCI control register 1 (SCICR1). • If SCISWAI is clear, the SCI operates normally when the CPU is in wait mode. • If SCISWAI is set, SCI clock generation ceases and the SCI module enters a power-conservation state when the CPU is in wait mode. Setting SCISWAI does not affect the state of the receiver enable bit, RE, or the transmitter enable bit, TE. If SCISWAI is set, any transmission or reception in progress stops at wait mode entry. The transmission or reception resumes when either an internal or external interrupt brings the CPU out of wait mode. Exiting wait mode by reset aborts any transmission or reception in progress and resets the SCI. 14.5.2.3 Stop Mode The SCI is inactive during stop mode for reduced power consumption. The STOP instruction does not affect the SCI register states, but the SCI bus clock will be disabled. The SCI operation resumes from where it left off after an external interrupt brings the CPU out of stop mode. Exiting stop mode by reset aborts any transmission or reception in progress and resets the SCI. The receive input active edge detect circuit is still active in stop mode. An active edge on the receive input can be used to bring the CPU out of stop mode. 14.5.3 Interrupt Operation This section describes the interrupt originated by the SCI block.The MCU must service the interrupt requests. Table 14-20 lists the eight interrupt sources of the SCI. Table 14-20. SCI Interrupt Sources Interrupt Source Local Enable Description TDRE SCISR1[7] TC SCISR1[6] TIE TCIE Active high level. Indicates that a byte was transferred from SCIDRH/L to the transmit shift register. Active high level. Indicates that a transmit is complete. RDRF SCISR1[5] RIE Active high level. The RDRF interrupt indicates that received data is available in the SCI data register. OR SCISR1[3] IDLE SCISR1[4] RXEDGIF SCIASR1[7] BERRIF SCIASR1[1] BKDIF SCIASR1[0] ILIE RXEDGIE BERRIE BRKDIE Active high level. This interrupt indicates that an overrun condition has occurred. Active high level. Indicates that receiver input has become idle. Active high level. Indicates that an active edge (falling for RXPOL = 0, rising for RXPOL = 1) was detected. Active high level. Indicates that a mismatch between transmitted and received data in a single wire application has happened. Active high level. Indicates that a break character has been received. S12XS-Family Reference Manual, Rev. 1.03 432 PRELIMINARY Freescale Semiconductor Serial Communication Interface (S12SCIV5) 14.5.3.1 Description of Interrupt Operation The SCI only originates interrupt requests. The following is a description of how the SCI makes a request and how the MCU should acknowledge that request. The interrupt vector offset and interrupt number are chip dependent. The SCI only has a single interrupt line (SCI Interrupt Signal, active high operation) and all the following interrupts, when generated, are ORed together and issued through that port. 14.5.3.1.1 TDRE Description The TDRE interrupt is set high by the SCI when the transmit shift register receives a byte from the SCI data register. A TDRE interrupt indicates that the transmit data register (SCIDRH/L) is empty and that a new byte can be written to the SCIDRH/L for transmission.Clear TDRE by reading SCI status register 1 with TDRE set and then writing to SCI data register low (SCIDRL). 14.5.3.1.2 TC Description The TC interrupt is set by the SCI when a transmission has been completed. Transmission is completed when all bits including the stop bit (if transmitted) have been shifted out and no data is queued to be transmitted. No stop bit is transmitted when sending a break character and the TC flag is set (providing there is no more data queued for transmission) when the break character has been shifted out. A TC interrupt indicates that there is no transmission in progress. TC is set high when the TDRE flag is set and no data, preamble, or break character is being transmitted. When TC is set, the TXD pin becomes idle (logic 1). Clear TC by reading SCI status register 1 (SCISR1) with TC set and then writing to SCI data register low (SCIDRL).TC is cleared automatically when data, preamble, or break is queued and ready to be sent. 14.5.3.1.3 RDRF Description The RDRF interrupt is set when the data in the receive shift register transfers to the SCI data register. A RDRF interrupt indicates that the received data has been transferred to the SCI data register and that the byte can now be read by the MCU. The RDRF interrupt is cleared by reading the SCI status register one (SCISR1) and then reading SCI data register low (SCIDRL). 14.5.3.1.4 OR Description The OR interrupt is set when software fails to read the SCI data register before the receive shift register receives the next frame. The newly acquired data in the shift register will be lost in this case, but the data already in the SCI data registers is not affected. The OR interrupt is cleared by reading the SCI status register one (SCISR1) and then reading SCI data register low (SCIDRL). 14.5.3.1.5 IDLE Description The IDLE interrupt is set when 10 consecutive logic 1s (if M = 0) or 11 consecutive logic 1s (if M = 1) appear on the receiver input. Once the IDLE is cleared, a valid frame must again set the RDRF flag before an idle condition can set the IDLE flag. Clear IDLE by reading SCI status register 1 (SCISR1) with IDLE set and then reading SCI data register low (SCIDRL). S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 433 Serial Communication Interface (S12SCIV5) 14.5.3.1.6 RXEDGIF Description The RXEDGIF interrupt is set when an active edge (falling if RXPOL = 0, rising if RXPOL = 1) on the RXD pin is detected. Clear RXEDGIF by writing a “1” to the SCIASR1 SCI alternative status register 1. 14.5.3.1.7 BERRIF Description The BERRIF interrupt is set when a mismatch between the transmitted and the received data in a single wire application like LIN was detected. Clear BERRIF by writing a “1” to the SCIASR1 SCI alternative status register 1. This flag is also cleared if the bit error detect feature is disabled. 14.5.3.1.8 BKDIF Description The BKDIF interrupt is set when a break signal was received. Clear BKDIF by writing a “1” to the SCIASR1 SCI alternative status register 1. This flag is also cleared if break detect feature is disabled. 14.5.4 Recovery from Wait Mode The SCI interrupt request can be used to bring the CPU out of wait mode. 14.5.5 Recovery from Stop Mode An active edge on the receive input can be used to bring the CPU out of stop mode. S12XS-Family Reference Manual, Rev. 1.03 434 PRELIMINARY Freescale Semiconductor Chapter 15 Serial Peripheral Interface (S12SPIV5) Table 15-1. Revision History Revision Number V05.00 Revision Date 24 Mar 2005 Sections Affected 15.3.2/15-439 Description of Changes - Added 16-bit transfer width feature. 15.1 Introduction The SPI module allows a duplex, synchronous, serial communication between the MCU and peripheral devices. Software can poll the SPI status flags or the SPI operation can be interrupt driven. 15.1.1 Glossary of Terms SPI SS SCK MOSI MISO MOMI SISO Serial Peripheral Interface Slave Select Serial Clock Master Output, Slave Input Master Input, Slave Output Master Output, Master Input Slave Input, Slave Output 15.1.2 Features The SPI includes these distinctive features: • Master mode and slave mode • Selectable 8 or 16-bit transfer width • Bidirectional mode • Slave select output • Mode fault error flag with CPU interrupt capability • Double-buffered data register • Serial clock with programmable polarity and phase • Control of SPI operation during wait mode 15.1.3 Modes of Operation The SPI functions in three modes: run, wait, and stop. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 435 Serial Peripheral Interface (S12SPIV5) • Run mode This is the basic mode of operation. • Wait mode SPI operation in wait mode is a configurable low power mode, controlled by the SPISWAI bit located in the SPICR2 register. In wait mode, if the SPISWAI bit is clear, the SPI operates like in run mode. If the SPISWAI bit is set, the SPI goes into a power conservative state, with the SPI clock generation turned off. If the SPI is configured as a master, any transmission in progress stops, but is resumed after CPU goes into run mode. If the SPI is configured as a slave, reception and transmission of data continues, so that the slave stays synchronized to the master. • Stop mode The SPI is inactive in stop mode for reduced power consumption. If the SPI is configured as a master, any transmission in progress stops, but is resumed after CPU goes into run mode. If the SPI is configured as a slave, reception and transmission of data continues, so that the slave stays synchronized to the master. For a detailed description of operating modes, please refer to Section 15.4.7, “Low Power Mode Options”. 15.1.4 Block Diagram Figure 15-1 gives an overview on the SPI architecture. The main parts of the SPI are status, control and data registers, shifter logic, baud rate generator, master/slave control logic, and port control logic. S12XS-Family Reference Manual, Rev. 1.03 436 PRELIMINARY Freescale Semiconductor Serial Peripheral Interface (S12SPIV5) SPI 2 SPI Control Register 1 BIDIROE 2 SPI Control Register 2 SPC0 SPI Interrupt Request Bus Clock SPI Status Register SPIF MODF SPTEF Interrupt Control Baud Rate Generator Counter Slave Control CPOL CPHA Slave Baud Rate Master Baud Rate Master Control Phase + Polarity Control Phase + Polarity Control SCK In SCK Out Port Control Logic Prescaler Clock Select Baud Rate SPPR 3 SPR 3 SPI Baud Rate Register LSBFE=1 Shift Clock Shifter LSBFE=0 Sample Clock Data In SPI Data Register LSBFE=1 MSB LSBFE=0 LSB LSBFE=0 LSBFE=1 Data Out MOSI SCK SS Figure 15-1. SPI Block Diagram 15.2 External Signal Description This section lists the name and description of all ports including inputs and outputs that do, or may, connect off chip. The SPI module has a total of four external pins. 15.2.1 MOSI — Master Out/Slave In Pin This pin is used to transmit data out of the SPI module when it is configured as a master and receive data when it is configured as slave. 15.2.2 MISO — Master In/Slave Out Pin This pin is used to transmit data out of the SPI module when it is configured as a slave and receive data when it is configured as master. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 437 Serial Peripheral Interface (S12SPIV5) 15.2.3 SS — Slave Select Pin This pin is used to output the select signal from the SPI module to another peripheral with which a data transfer is to take place when it is configured as a master and it is used as an input to receive the slave select signal when the SPI is configured as slave. 15.2.4 SCK — Serial Clock Pin In master mode, this is the synchronous output clock. In slave mode, this is the synchronous input clock. 15.3 Memory Map and Register Definition This section provides a detailed description of address space and registers used by the SPI. 15.3.1 Module Memory Map The memory map for the SPI is given in Figure 15-2. The address listed for each register is the sum of a base address and an address offset. The base address is defined at the SoC level and the address offset is defined at the module level. Reads from the reserved bits return zeros and writes to the reserved bits have no effect. Register Name Bit 7 0x0000 R SPICR1 W SPIE 0x0001 R 0 SPICR2 W 0x0002 R 0 SPIBR W 0x0003 SPISR R SPIF W 0x0004 R R15 SPIDRH W T15 0x0005 R R7 SPIDRL W T7 0x0006 R Reserved W 0x0007 R Reserved W 6 SPE XFRW SPPR2 0 5 4 3 SPTIE MSTR CPOL 0 MODFEN BIDIROE 0 SPPR1 SPPR0 SPTEF MODF 0 R14 R13 R12 R11 T14 T13 T12 T11 R6 R5 R4 R3 T6 T5 T4 T3 = Unimplemented or Reserved Figure 15-2. SPI Register Summary 2 CPHA 0 SPR2 0 R10 T10 R2 T2 1 SSOE SPISWAI SPR1 0 R9 T9 R1 T1 Bit 0 LSBFE SPC0 SPR0 0 R8 T8 R0 T0 S12XS-Family Reference Manual, Rev. 1.03 438 PRELIMINARY Freescale Semiconductor Serial Peripheral Interface (S12SPIV5) 15.3.2 Register Descriptions This section consists of register descriptions in address order. Each description includes a standard register diagram with an associated figure number. Details of register bit and field function follow the register diagrams, in bit order. 15.3.2.1 SPI Control Register 1 (SPICR1) Module Base +0x0000 R W Reset 7 SPIE 0 6 SPE 5 SPTIE 4 MSTR 3 CPOL 2 CPHA 0 0 0 0 1 Figure 15-3. SPI Control Register 1 (SPICR1) 1 SSOE 0 0 LSBFE 0 Read: Anytime Write: Anytime Table 15-2. SPICR1 Field Descriptions Field 7 SPIE 6 SPE 5 SPTIE 4 MSTR 3 CPOL 2 CPHA Description SPI Interrupt Enable Bit — This bit enables SPI interrupt requests, if SPIF or MODF status flag is set. 0 SPI interrupts disabled. 1 SPI interrupts enabled. SPI System Enable Bit — This bit enables the SPI system and dedicates the SPI port pins to SPI system functions. If SPE is cleared, SPI is disabled and forced into idle state, status bits in SPISR register are reset. 0 SPI disabled (lower power consumption). 1 SPI enabled, port pins are dedicated to SPI functions. SPI Transmit Interrupt Enable — This bit enables SPI interrupt requests, if SPTEF flag is set. 0 SPTEF interrupt disabled. 1 SPTEF interrupt enabled. SPI Master/Slave Mode Select Bit — This bit selects whether the SPI operates in master or slave mode. Switching the SPI from master to slave or vice versa forces the SPI system into idle state. 0 SPI is in slave mode. 1 SPI is in master mode. SPI Clock Polarity Bit — This bit selects an inverted or non-inverted SPI clock. To transmit data between SPI modules, the SPI modules must have identical CPOL values. In master mode, a change of this bit will abort a transmission in progress and force the SPI system into idle state. 0 Active-high clocks selected. In idle state SCK is low. 1 Active-low clocks selected. In idle state SCK is high. SPI Clock Phase Bit — This bit is used to select the SPI clock format. In master mode, a change of this bit will abort a transmission in progress and force the SPI system into idle state. 0 Sampling of data occurs at odd edges (1,3,5,...) of the SCK clock. 1 Sampling of data occurs at even edges (2,4,6,...) of the SCK clock. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 439 Serial Peripheral Interface (S12SPIV5) Table 15-2. SPICR1 Field Descriptions (continued) Field 1 SSOE 0 LSBFE Description Slave Select Output Enable — The SS output feature is enabled only in master mode, if MODFEN is set, by asserting the SSOE as shown in Table 15-3. In master mode, a change of this bit will abort a transmission in progress and force the SPI system into idle state. LSB-First Enable — This bit does not affect the position of the MSB and LSB in the data register. Reads and writes of the data register always have the MSB in the highest bit position. In master mode, a change of this bit will abort a transmission in progress and force the SPI system into idle state. 0 Data is transferred most significant bit first. 1 Data is transferred least significant bit first. MODFEN 0 0 1 1 Table 15-3. SS Input / Output Selection SSOE 0 1 0 1 Master Mode SS not used by SPI SS not used by SPI SS input with MODF feature SS is slave select output Slave Mode SS input SS input SS input SS input 15.3.2.2 SPI Control Register 2 (SPICR2) Module Base +0x0001 7 R 0 W 6 XFRW 5 4 3 2 0 0 MODFEN BIDIROE Reset 0 0 0 0 0 0 = Unimplemented or Reserved Figure 15-4. SPI Control Register 2 (SPICR2) Read: Anytime Write: Anytime; writes to the reserved bits have no effect 1 SPISWAI 0 0 SPC0 0 S12XS-Family Reference Manual, Rev. 1.03 440 PRELIMINARY Freescale Semiconductor Serial Peripheral Interface (S12SPIV5) Table 15-4. SPICR2 Field Descriptions Field Description 6 XFRW Transfer Width — This bit is used for selecting the data transfer width. If 8-bit transfer width is selected, SPIDRL becomes the dedicated data register and SPIDRH is unused. If 16-bit transfer width is selected, SPIDRH and SPIDRL form a 16-bit data register. Please refer to Section 15.3.2.4, “SPI Status Register (SPISR) for information about transmit/receive data handling and the interrupt flag clearing mechanism. In master mode, a change of this bit will abort a transmission in progress and force the SPI system into idle state. 0 8-bit Transfer Width (n = 8)1 1 16-bit Transfer Width (n = 16)1 4 MODFEN Mode Fault Enable Bit — This bit allows the MODF failure to be detected. If the SPI is in master mode and MODFEN is cleared, then the SS port pin is not used by the SPI. In slave mode, the SS is available only as an input regardless of the value of MODFEN. For an overview on the impact of the MODFEN bit on the SS port pin configuration, refer to Table 15-3. In master mode, a change of this bit will abort a transmission in progress and force the SPI system into idle state. 0 SS port pin is not used by the SPI. 1 SS port pin with MODF feature. 3 BIDIROE Output Enable in the Bidirectional Mode of Operation — This bit controls the MOSI and MISO output buffer of the SPI, when in bidirectional mode of operation (SPC0 is set). In master mode, this bit controls the output buffer of the MOSI port, in slave mode it controls the output buffer of the MISO port. In master mode, with SPC0 set, a change of this bit will abort a transmission in progress and force the SPI into idle state. 0 Output buffer disabled. 1 Output buffer enabled. 1 SPISWAI SPI Stop in Wait Mode Bit — This bit is used for power conservation while in wait mode. 0 SPI clock operates normally in wait mode. 1 Stop SPI clock generation when in wait mode. 0 Serial Pin Control Bit 0 — This bit enables bidirectional pin configurations as shown in Table 15-5. In master SPC0 mode, a change of this bit will abort a transmission in progress and force the SPI system into idle state. 1 n is used later in this document as a placeholder for the selected transfer width. Pin Mode Normal Bidirectional Normal Bidirectional Table 15-5. Bidirectional Pin Configurations SPC0 0 1 0 1 BIDIROE MISO Master Mode of Operation X Master In 0 MISO not used by SPI 1 Slave Mode of Operation X Slave Out 0 Slave In 1 Slave I/O MOSI Master Out Master In Master I/O Slave In MOSI not used by SPI S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 441 Serial Peripheral Interface (S12SPIV5) 15.3.2.3 SPI Baud Rate Register (SPIBR) Module Base +0x0002 7 6 5 4 3 R 0 0 SPPR2 SPPR1 SPPR0 W Reset 0 0 0 0 0 = Unimplemented or Reserved 2 SPR2 0 Figure 15-5. SPI Baud Rate Register (SPIBR) Read: Anytime Write: Anytime; writes to the reserved bits have no effect 1 SPR1 0 0 SPR0 0 Table 15-6. SPIBR Field Descriptions Field Description 6–4 SPI Baud Rate Preselection Bits — These bits specify the SPI baud rates as shown in Table 15-7. In master SPPR[2:0] mode, a change of these bits will abort a transmission in progress and force the SPI system into idle state. 2–0 SPI Baud Rate Selection Bits — These bits specify the SPI baud rates as shown in Table 15-7. In master mode, SPR[2:0] a change of these bits will abort a transmission in progress and force the SPI system into idle state. The baud rate divisor equation is as follows: BaudRateDivisor = (SPPR + 1) • 2(SPR + 1) Eqn. 15-1 The baud rate can be calculated with the following equation: Baud Rate = BusClock / BaudRateDivisor NOTE For maximum allowed baud rates, please refer to the SPI Electrical Specification in the Electricals chapter of this data sheet. Eqn. 15-2 SPPR2 0 0 0 0 0 0 0 0 0 0 0 0 Table 15-7. Example SPI Baud Rate Selection (25 MHz Bus Clock) (Sheet 1 of 3) SPPR1 0 0 0 0 0 0 0 0 0 0 0 0 SPPR0 0 0 0 0 0 0 0 0 1 1 1 1 SPR2 0 0 0 0 1 1 1 1 0 0 0 0 SPR1 0 0 1 1 0 0 1 1 0 0 1 1 SPR0 0 1 0 1 0 1 0 1 0 1 0 1 Baud Rate Divisor 2 4 8 16 32 64 128 256 4 8 16 32 Baud Rate 12.5 Mbit/s 6.25 Mbit/s 3.125 Mbit/s 1.5625 Mbit/s 781.25 kbit/s 390.63 kbit/s 195.31 kbit/s 97.66 kbit/s 6.25 Mbit/s 3.125 Mbit/s 1.5625 Mbit/s 781.25 kbit/s S12XS-Family Reference Manual, Rev. 1.03 442 PRELIMINARY Freescale Semiconductor SPPR2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Serial Peripheral Interface (S12SPIV5) Table 15-7. Example SPI Baud Rate Selection (25 MHz Bus Clock) (Sheet 2 of 3) SPPR1 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 SPPR0 1 1 1 1 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 0 0 0 0 0 0 SPR2 1 1 1 1 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1 0 0 0 0 1 1 SPR1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 SPR0 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 Baud Rate Divisor 64 128 256 512 6 12 24 48 96 192 384 768 8 16 32 64 128 256 512 1024 10 20 40 80 160 320 640 1280 12 24 48 96 192 384 768 1536 14 28 56 112 224 448 Baud Rate 390.63 kbit/s 195.31 kbit/s 97.66 kbit/s 48.83 kbit/s 4.16667 Mbit/s 2.08333 Mbit/s 1.04167 Mbit/s 520.83 kbit/s 260.42 kbit/s 130.21 kbit/s 65.10 kbit/s 32.55 kbit/s 3.125 Mbit/s 1.5625 Mbit/s 781.25 kbit/s 390.63 kbit/s 195.31 kbit/s 97.66 kbit/s 48.83 kbit/s 24.41 kbit/s 2.5 Mbit/s 1.25 Mbit/s 625 kbit/s 312.5 kbit/s 156.25 kbit/s 78.13 kbit/s 39.06 kbit/s 19.53 kbit/s 2.08333 Mbit/s 1.04167 Mbit/s 520.83 kbit/s 260.42 kbit/s 130.21 kbit/s 65.10 kbit/s 32.55 kbit/s 16.28 kbit/s 1.78571 Mbit/s 892.86 kbit/s 446.43 kbit/s 223.21 kbit/s 111.61 kbit/s 55.80 kbit/s S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 443 Serial Peripheral Interface (S12SPIV5) SPPR2 1 1 1 1 1 1 1 1 1 1 Table 15-7. Example SPI Baud Rate Selection (25 MHz Bus Clock) (Sheet 3 of 3) SPPR1 1 1 1 1 1 1 1 1 1 1 SPPR0 0 0 1 1 1 1 1 1 1 1 SPR2 1 1 0 0 0 0 1 1 1 1 SPR1 1 1 0 0 1 1 0 0 1 1 SPR0 0 1 0 1 0 1 0 1 0 1 Baud Rate Divisor 896 1792 16 32 64 128 256 512 1024 2048 Baud Rate 27.90 kbit/s 13.95 kbit/s 1.5625 Mbit/s 781.25 kbit/s 390.63 kbit/s 195.31 kbit/s 97.66 kbit/s 48.83 kbit/s 24.41 kbit/s 12.21 kbit/s 15.3.2.4 SPI Status Register (SPISR) Module Base +0x0003 7 6 5 4 3 2 1 0 R SPIF 0 SPTEF MODF 0 0 0 0 W Reset 0 0 1 0 0 0 0 0 = Unimplemented or Reserved Figure 15-6. SPI Status Register (SPISR) Read: Anytime Write: Has no effect Table 15-8. SPISR Field Descriptions Field 7 SPIF 5 SPTEF 4 MODF Description SPIF Interrupt Flag — This bit is set after received data has been transferred into the SPI data register. For information about clearing SPIF Flag, please refer to Table 15-9. 0 Transfer not yet complete. 1 New data copied to SPIDR. SPI Transmit Empty Interrupt Flag — If set, this bit indicates that the transmit data register is empty. For information about clearing this bit and placing data into the transmit data register, please refer to Table 15-10. 0 SPI data register not empty. 1 SPI data register empty. Mode Fault Flag — This bit is set if the SS input becomes low while the SPI is configured as a master and mode fault detection is enabled, MODFEN bit of SPICR2 register is set. Refer to MODFEN bit description in Section 15.3.2.2, “SPI Control Register 2 (SPICR2)”. The flag is cleared automatically by a read of the SPI status register (with MODF set) followed by a write to the SPI control register 1. 0 Mode fault has not occurred. 1 Mode fault has occurred. S12XS-Family Reference Manual, Rev. 1.03 444 PRELIMINARY Freescale Semiconductor Serial Peripheral Interface (S12SPIV5) Table 15-9. SPIF Interrupt Flag Clearing Sequence XFRW Bit SPIF Interrupt Flag Clearing Sequence 0 Read SPISR with SPIF == 1 then Read SPIDRL 1 Read SPISR with SPIF == 1 Byte Read SPIDRL 1 or then Byte Read SPIDRH 2 Byte Read SPIDRL or Word Read (SPIDRH:SPIDRL) 1 Data in SPIDRH is lost in this case. 2 SPIDRH can be read repeatedly without any effect on SPIF. SPIF Flag is cleared only by the read of SPIDRL after reading SPISR with SPIF == 1. Table 15-10. SPTEF Interrupt Flag Clearing Sequence XFRW Bit SPTEF Interrupt Flag Clearing Sequence 0 Read SPISR with SPTEF == 1 then Write to SPIDRL 1 1 Read SPISR with SPTEF == 1 Byte Write to SPIDRL 12 or then Byte Write to SPIDRH 13 Byte Write to SPIDRL 1 or Word Write to (SPIDRH:SPIDRL) 1 1 Any write to SPIDRH or SPIDRL with SPTEF == 0 is effectively ignored. 2 Data in SPIDRH is undefined in this case. 3 SPIDRH can be written repeatedly without any effect on SPTEF. SPTEF Flag is cleared only by writing to SPIDRL after reading SPISR with SPTEF == 1. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 445 Serial Peripheral Interface (S12SPIV5) 15.3.2.5 SPI Data Register (SPIDR = SPIDRH:SPIDRL) Module Base +0x0004 7 6 5 4 3 2 1 0 R R15 R14 R13 R12 R11 R10 R9 R8 W T15 T14 T13 T12 T11 T10 T9 T8 Reset 0 0 0 0 0 0 0 0 Figure 15-7. SPI Data Register High (SPIDRH) Module Base +0x0005 7 6 5 4 3 2 1 0 R R7 R6 R5 R4 R3 R2 R1 R0 W T7 T6 T5 T4 T3 T2 T1 T0 Reset 0 0 0 0 0 0 0 0 Figure 15-8. SPI Data Register Low (SPIDRL) Read: Anytime; read data only valid when SPIF is set Write: Anytime The SPI data register is both the input and output register for SPI data. A write to this register allows data to be queued and transmitted. For an SPI configured as a master, queued data is transmitted immediately after the previous transmission has completed. The SPI transmitter empty flag SPTEF in the SPISR register indicates when the SPI data register is ready to accept new data. Received data in the SPIDR is valid when SPIF is set. If SPIF is cleared and data has been received, the received data is transferred from the receive shift register to the SPIDR and SPIF is set. If SPIF is set and not serviced, and a second data value has been received, the second received data is kept as valid data in the receive shift register until the start of another transmission. The data in the SPIDR does not change. If SPIF is set and valid data is in the receive shift register, and SPIF is serviced before the start of a third transmission, the data in the receive shift register is transferred into the SPIDR and SPIF remains set (see Figure 15-9). If SPIF is set and valid data is in the receive shift register, and SPIF is serviced after the start of a third transmission, the data in the receive shift register has become invalid and is not transferred into the SPIDR (see Figure 15-10). S12XS-Family Reference Manual, Rev. 1.03 446 PRELIMINARY Freescale Semiconductor Data A Received Receive Shift Register Data A Serial Peripheral Interface (S12SPIV5) Data B Received Data C Received SPIF Serviced Data B Data C SPIF SPI Data Register Data A Data B Data C = Unspecified = Reception in progress Figure 15-9. Reception with SPIF serviced in Time Data A Received Receive Shift Register SPIF Data A Data B Received Data C Received Data B Lost SPIF Serviced Data B Data C SPI Data Register Data A Data C = Unspecified = Reception in progress Figure 15-10. Reception with SPIF serviced too late 15.4 Functional Description The SPI module allows a duplex, synchronous, serial communication between the MCU and peripheral devices. Software can poll the SPI status flags or SPI operation can be interrupt driven. The SPI system is enabled by setting the SPI enable (SPE) bit in SPI control register 1. While SPE is set, the four associated SPI port pins are dedicated to the SPI function as: • Slave select (SS) • Serial clock (SCK) • Master out/slave in (MOSI) • Master in/slave out (MISO) S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 447 Serial Peripheral Interface (S12SPIV5) The main element of the SPI system is the SPI data register. The n-bit1 data register in the master and the n-bit1 data register in the slave are linked by the MOSI and MISO pins to form a distributed 2n-bit1 register. When a data transfer operation is performed, this 2n-bit1 register is serially shifted n1 bit positions by the S-clock from the master, so data is exchanged between the master and the slave. Data written to the master SPI data register becomes the output data for the slave, and data read from the master SPI data register after a transfer operation is the input data from the slave. A read of SPISR with SPTEF = 1 followed by a write to SPIDR puts data into the transmit data register. When a transfer is complete and SPIF is cleared, received data is moved into the receive data register. This data register acts as the SPI receive data register for reads and as the SPI transmit data register for writes. A common SPI data register address is shared for reading data from the read data buffer and for writing data to the transmit data register. The clock phase control bit (CPHA) and a clock polarity control bit (CPOL) in the SPI control register 1 (SPICR1) select one of four possible clock formats to be used by the SPI system. The CPOL bit simply selects a non-inverted or inverted clock. The CPHA bit is used to accommodate two fundamentally different protocols by sampling data on odd numbered SCK edges or on even numbered SCK edges (see Section 15.4.3, “Transmission Formats”). The SPI can be configured to operate as a master or as a slave. When the MSTR bit in SPI control register1 is set, master mode is selected, when the MSTR bit is clear, slave mode is selected. NOTE A change of CPOL or MSTR bit while there is a received byte pending in the receive shift register will destroy the received byte and must be avoided. 15.4.1 Master Mode The SPI operates in master mode when the MSTR bit is set. Only a master SPI module can initiate transmissions. A transmission begins by writing to the master SPI data register. If the shift register is empty, data immediately transfers to the shift register. Data begins shifting out on the MOSI pin under the control of the serial clock. • Serial clock The SPR2, SPR1, and SPR0 baud rate selection bits, in conjunction with the SPPR2, SPPR1, and SPPR0 baud rate preselection bits in the SPI baud rate register, control the baud rate generator and determine the speed of the transmission. The SCK pin is the SPI clock output. Through the SCK pin, the baud rate generator of the master controls the shift register of the slave peripheral. • MOSI, MISO pin In master mode, the function of the serial data output pin (MOSI) and the serial data input pin (MISO) is determined by the SPC0 and BIDIROE control bits. • SS pin If MODFEN and SSOE are set, the SS pin is configured as slave select output. The SS output becomes low during each transmission and is high when the SPI is in idle state. If MODFEN is set and SSOE is cleared, the SS pin is configured as input for detecting mode fault error. If the SS input becomes low this indicates a mode fault error where another master tries to 1. n depends on the selected transfer width, please refer to Section 15.3.2.2, “SPI Control Register 2 (SPICR2) S12XS-Family Reference Manual, Rev. 1.03 448 PRELIMINARY Freescale Semiconductor Serial Peripheral Interface (S12SPIV5) drive the MOSI and SCK lines. In this case, the SPI immediately switches to slave mode, by clearing the MSTR bit and also disables the slave output buffer MISO (or SISO in bidirectional mode). So the result is that all outputs are disabled and SCK, MOSI, and MISO are inputs. If a transmission is in progress when the mode fault occurs, the transmission is aborted and the SPI is forced into idle state. This mode fault error also sets the mode fault (MODF) flag in the SPI status register (SPISR). If the SPI interrupt enable bit (SPIE) is set when the MODF flag becomes set, then an SPI interrupt sequence is also requested. When a write to the SPI data register in the master occurs, there is a half SCK-cycle delay. After the delay, SCK is started within the master. The rest of the transfer operation differs slightly, depending on the clock format specified by the SPI clock phase bit, CPHA, in SPI control register 1 (see Section 15.4.3, “Transmission Formats”). NOTE A change of the bits CPOL, CPHA, SSOE, LSBFE, XFRW, MODFEN, SPC0, or BIDIROE with SPC0 set, SPPR2-SPPR0 and SPR2-SPR0 in master mode will abort a transmission in progress and force the SPI into idle state. The remote slave cannot detect this, therefore the master must ensure that the remote slave is returned to idle state. 15.4.2 Slave Mode The SPI operates in slave mode when the MSTR bit in SPI control register 1 is clear. • Serial clock In slave mode, SCK is the SPI clock input from the master. • MISO, MOSI pin In slave mode, the function of the serial data output pin (MISO) and serial data input pin (MOSI) is determined by the SPC0 bit and BIDIROE bit in SPI control register 2. • SS pin The SS pin is the slave select input. Before a data transmission occurs, the SS pin of the slave SPI must be low. SS must remain low until the transmission is complete. If SS goes high, the SPI is forced into idle state. The SS input also controls the serial data output pin, if SS is high (not selected), the serial data output pin is high impedance, and, if SS is low, the first bit in the SPI data register is driven out of the serial data output pin. Also, if the slave is not selected (SS is high), then the SCK input is ignored and no internal shifting of the SPI shift register occurs. Although the SPI is capable of duplex operation, some SPI peripherals are capable of only receiving SPI data in a slave mode. For these simpler devices, there is no serial data out pin. NOTE When peripherals with duplex capability are used, take care not to simultaneously enable two receivers whose serial outputs drive the same system slave’s serial data output line. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 449 Serial Peripheral Interface (S12SPIV5) As long as no more than one slave device drives the system slave’s serial data output line, it is possible for several slaves to receive the same transmission from a master, although the master would not receive return information from all of the receiving slaves. If the CPHA bit in SPI control register 1 is clear, odd numbered edges on the SCK input cause the data at the serial data input pin to be latched. Even numbered edges cause the value previously latched from the serial data input pin to shift into the LSB or MSB of the SPI shift register, depending on the LSBFE bit. If the CPHA bit is set, even numbered edges on the SCK input cause the data at the serial data input pin to be latched. Odd numbered edges cause the value previously latched from the serial data input pin to shift into the LSB or MSB of the SPI shift register, depending on the LSBFE bit. When CPHA is set, the first edge is used to get the first data bit onto the serial data output pin. When CPHA is clear and the SS input is low (slave selected), the first bit of the SPI data is driven out of the serial data output pin. After the nth1 shift, the transfer is considered complete and the received data is transferred into the SPI data register. To indicate transfer is complete, the SPIF flag in the SPI status register is set. NOTE A change of the bits CPOL, CPHA, SSOE, LSBFE, MODFEN, SPC0, or BIDIROE with SPC0 set in slave mode will corrupt a transmission in progress and must be avoided. 15.4.3 Transmission Formats During an SPI transmission, data is transmitted (shifted out serially) and received (shifted in serially) simultaneously. The serial clock (SCK) synchronizes shifting and sampling of the information on the two serial data lines. A slave select line allows selection of an individual slave SPI device; slave devices that are not selected do not interfere with SPI bus activities. Optionally, on a master SPI device, the slave select line can be used to indicate multiple-master bus contention. MASTER SPI SLAVE SPI SHIFT REGISTER MISO MOSI BAUD RATE GENERATOR SCK SS VDD MISO MOSI SCK SS SHIFT REGISTER Figure 15-11. Master/Slave Transfer Block Diagram 15.4.3.1 Clock Phase and Polarity Controls Using two bits in the SPI control register 1, software selects one of four combinations of serial clock phase and polarity. 1. n depends on the selected transfer width, please refer to Section 15.3.2.2, “SPI Control Register 2 (SPICR2) S12XS-Family Reference Manual, Rev. 1.03 450 PRELIMINARY Freescale Semiconductor Serial Peripheral Interface (S12SPIV5) The CPOL clock polarity control bit specifies an active high or low clock and has no significant effect on the transmission format. The CPHA clock phase control bit selects one of two fundamentally different transmission formats. Clock phase and polarity should be identical for the master SPI device and the communicating slave device. In some cases, the phase and polarity are changed between transmissions to allow a master device to communicate with peripheral slaves having different requirements. 15.4.3.2 CPHA = 0 Transfer Format The first edge on the SCK line is used to clock the first data bit of the slave into the master and the first data bit of the master into the slave. In some peripherals, the first bit of the slave’s data is available at the slave’s data out pin as soon as the slave is selected. In this format, the first SCK edge is issued a half cycle after SS has become low. A half SCK cycle later, the second edge appears on the SCK line. When this second edge occurs, the value previously latched from the serial data input pin is shifted into the LSB or MSB of the shift register, depending on LSBFE bit. After this second edge, the next bit of the SPI master data is transmitted out of the serial data output pin of the master to the serial input pin on the slave. This process continues for a total of 16 edges on the SCK line, with data being latched on odd numbered edges and shifted on even numbered edges. Data reception is double buffered. Data is shifted serially into the SPI shift register during the transfer and is transferred to the parallel SPI data register after the last bit is shifted in. After 2n1 (last) SCK edges: • Data that was previously in the master SPI data register should now be in the slave data register and the data that was in the slave data register should be in the master. • The SPIF flag in the SPI status register is set, indicating that the transfer is complete. Figure 15-12 is a timing diagram of an SPI transfer where CPHA = 0. SCK waveforms are shown for CPOL = 0 and CPOL = 1. The diagram may be interpreted as a master or slave timing diagram because the SCK, MISO, and MOSI pins are connected directly between the master and the slave. The MISO signal is the output from the slave and the MOSI signal is the output from the master. The SS pin of the master must be either high or reconfigured as a general-purpose output not affecting the SPI. 1. n depends on the selected transfer width, please refer to Section 15.3.2.2, “SPI Control Register 2 (SPICR2) S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 451 Serial Peripheral Interface (S12SPIV5) End of Idle State SCK Edge Number SCK (CPOL = 0) SCK (CPOL = 1) Begin Transfer End Begin of Idle State 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 If next transfer begins here SAMPLE I MOSI/MISO CHANGE O MOSI pin CHANGE O MISO pin SEL SS (O) Master only SEL SS (I) tL MSB first (LSBFE = 0): MSB LSB first (LSBFE = 1): LSB Bit 6 Bit 1 Bit 5 Bit 2 Bit 4 Bit 3 Bit 3 Bit 4 Bit 2 Bit 5 tL = Minimum leading time before the first SCK edge tT = Minimum trailing time after the last SCK edge tI = Minimum idling time between transfers (minimum SS high time) tL, tT, and tI are guaranteed for the master mode and required for the slave mode. Bit 1 Bit 6 tT tI tL LSB Minimum 1/2 SCK MSB for tT, tl, tL Figure 15-12. SPI Clock Format 0 (CPHA = 0), with 8-bit Transfer Width selected (XFRW = 0) S12XS-Family Reference Manual, Rev. 1.03 452 PRELIMINARY Freescale Semiconductor Serial Peripheral Interface (S12SPIV5) End of Idle State SCK Edge Number SCK (CPOL = 0) Begin Transfer End Begin of Idle State 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 SCK (CPOL = 1) SAMPLE I MOSI/MISO If next transfer begins here CHANGE O MOSI pin CHANGE O MISO pin SEL SS (O) Master only SEL SS (I) tL tT tI tL MSB first (LSBFE = 0) MSB Bit 14Bit 13Bit 12Bit 11Bit 10 Bit 9 Bit 8 Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 LSB Minimum 1/2 SCK LSB first (LSBFE = 1) LSB Bit 1 Bit 2 Bit 3 Bit 4 Bit 5 Bit 6 Bit 7 Bit 8 Bit 9 Bit 10Bit 11Bit 12Bit 13Bit 14 MSB for tT, tl, tL tL = Minimum leading time before the first SCK edge tT = Minimum trailing time after the last SCK edge tI = Minimum idling time between transfers (minimum SS high time) tL, tT, and tI are guaranteed for the master mode and required for the slave mode. Figure 15-13. SPI Clock Format 0 (CPHA = 0), with 16-Bit Transfer Width selected (XFRW = 1) In slave mode, if the SS line is not deasserted between the successive transmissions then the content of the SPI data register is not transmitted; instead the last received data is transmitted. If the SS line is deasserted for at least minimum idle time (half SCK cycle) between successive transmissions, then the content of the SPI data register is transmitted. In master mode, with slave select output enabled the SS line is always deasserted and reasserted between successive transfers for at least minimum idle time. 15.4.3.3 CPHA = 1 Transfer Format Some peripherals require the first SCK edge before the first data bit becomes available at the data out pin, the second edge clocks data into the system. In this format, the first SCK edge is issued by setting the CPHA bit at the beginning of the n1-cycle transfer operation. The first edge of SCK occurs immediately after the half SCK clock cycle synchronization delay. This first edge commands the slave to transfer its first data bit to the serial data input pin of the master. A half SCK cycle later, the second edge appears on the SCK pin. This is the latching edge for both the master and slave. 1. n depends on the selected transfer width, please refer to Section 15.3.2.2, “SPI Control Register 2 (SPICR2) S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 453 Serial Peripheral Interface (S12SPIV5) When the third edge occurs, the value previously latched from the serial data input pin is shifted into the LSB or MSB of the SPI shift register, depending on LSBFE bit. After this edge, the next bit of the master data is coupled out of the serial data output pin of the master to the serial input pin on the slave. This process continues for a total of n1 edges on the SCK line with data being latched on even numbered edges and shifting taking place on odd numbered edges. Data reception is double buffered, data is serially shifted into the SPI shift register during the transfer and is transferred to the parallel SPI data register after the last bit is shifted in. After 2n1 SCK edges: • Data that was previously in the SPI data register of the master is now in the data register of the slave, and data that was in the data register of the slave is in the master. • The SPIF flag bit in SPISR is set indicating that the transfer is complete. Figure 15-14 shows two clocking variations for CPHA = 1. The diagram may be interpreted as a master or slave timing diagram because the SCK, MISO, and MOSI pins are connected directly between the master and the slave. The MISO signal is the output from the slave, and the MOSI signal is the output from the master. The SS line is the slave select input to the slave. The SS pin of the master must be either high or reconfigured as a general-purpose output not affecting the SPI. End of Idle State SCK Edge Number Begin Transfer End 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Begin of Idle State SCK (CPOL = 0) SCK (CPOL = 1) If next transfer begins here SAMPLE I MOSI/MISO CHANGE O MOSI pin CHANGE O MISO pin SEL SS (O) Master only SEL SS (I) tL tT tI tL MSB first (LSBFE = 0): MSB LSB first (LSBFE = 1): LSB Bit 6 Bit 1 Bit 5 Bit 2 Bit 4 Bit 3 Bit 3 Bit 4 Bit 2 Bit 5 Bit 1 Bit 6 LSB Minimum 1/2 SCK MSB for tT, tl, tL tL = Minimum leading time before the first SCK edge, not required for back-to-back transfers tT = Minimum trailing time after the last SCK edge tI = Minimum idling time between transfers (minimum SS high time), not required for back-to-back transfers Figure 15-14. SPI Clock Format 1 (CPHA = 1), with 8-Bit Transfer Width selected (XFRW = 0) S12XS-Family Reference Manual, Rev. 1.03 454 PRELIMINARY Freescale Semiconductor Serial Peripheral Interface (S12SPIV5) End of Idle State SCK Edge Number SCK (CPOL = 0) Begin Transfer End Begin of Idle State 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 SCK (CPOL = 1) SAMPLE I MOSI/MISO If next transfer begins here CHANGE O MOSI pin CHANGE O MISO pin SEL SS (O) Master only SEL SS (I) MSB first (LSBFE = 0) LSB first (LSBFE = 1) tL tT tI tL MSB Bit 14Bit 13Bit 12Bit 11Bit 10 Bit 9 Bit 8 Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 LSB Minimum 1/2 SCK LSB Bit 1 Bit 2 Bit 3 Bit 4 Bit 5 Bit 6 Bit 7 Bit 8 Bit 9 Bit 10Bit 11Bit 12Bit 13Bit 14 MSB for tT, tl, tL tL = Minimum leading time before the first SCK edge, not required for back-to-back transfers tT = Minimum trailing time after the last SCK edge tI = Minimum idling time between transfers (minimum SS high time), not required for back-to-back transfers Figure 15-15. SPI Clock Format 1 (CPHA = 1), with 16-Bit Transfer Width selected (XFRW = 1) The SS line can remain active low between successive transfers (can be tied low at all times). This format is sometimes preferred in systems having a single fixed master and a single slave that drive the MISO data line. • Back-to-back transfers in master mode In master mode, if a transmission has completed and new data is available in the SPI data register, this data is sent out immediately without a trailing and minimum idle time. The SPI interrupt request flag (SPIF) is common to both the master and slave modes. SPIF gets set one half SCK cycle after the last SCK edge. 15.4.4 SPI Baud Rate Generation Baud rate generation consists of a series of divider stages. Six bits in the SPI baud rate register (SPPR2, SPPR1, SPPR0, SPR2, SPR1, and SPR0) determine the divisor to the SPI module clock which results in the SPI baud rate. The SPI clock rate is determined by the product of the value in the baud rate preselection bits (SPPR2–SPPR0) and the value in the baud rate selection bits (SPR2–SPR0). The module clock divisor equation is shown in Equation 15-3. BaudRateDivisor = (SPPR + 1) • 2(SPR + 1) Eqn. 15-3 S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 455 Serial Peripheral Interface (S12SPIV5) When all bits are clear (the default condition), the SPI module clock is divided by 2. When the selection bits (SPR2–SPR0) are 001 and the preselection bits (SPPR2–SPPR0) are 000, the module clock divisor becomes 4. When the selection bits are 010, the module clock divisor becomes 8, etc. When the preselection bits are 001, the divisor determined by the selection bits is multiplied by 2. When the preselection bits are 010, the divisor is multiplied by 3, etc. See Table 15-7 for baud rate calculations for all bit conditions, based on a 25 MHz bus clock. The two sets of selects allows the clock to be divided by a non-power of two to achieve other baud rates such as divide by 6, divide by 10, etc. The baud rate generator is activated only when the SPI is in master mode and a serial transfer is taking place. In the other cases, the divider is disabled to decrease IDD current. NOTE For maximum allowed baud rates, please refer to the SPI Electrical Specification in the Electricals chapter of this data sheet. 15.4.5 Special Features 15.4.5.1 SS Output The SS output feature automatically drives the SS pin low during transmission to select external devices and drives it high during idle to deselect external devices. When SS output is selected, the SS output pin is connected to the SS input pin of the external device. The SS output is available only in master mode during normal SPI operation by asserting SSOE and MODFEN bit as shown in Table 15-3. The mode fault feature is disabled while SS output is enabled. NOTE Care must be taken when using the SS output feature in a multimaster system because the mode fault feature is not available for detecting system errors between masters. 15.4.5.2 Bidirectional Mode (MOMI or SISO) The bidirectional mode is selected when the SPC0 bit is set in SPI control register 2 (see Table 15-11). In this mode, the SPI uses only one serial data pin for the interface with external device(s). The MSTR bit decides which pin to use. The MOSI pin becomes the serial data I/O (MOMI) pin for the master mode, and the MISO pin becomes serial data I/O (SISO) pin for the slave mode. The MISO pin in master mode and MOSI pin in slave mode are not used by the SPI. S12XS-Family Reference Manual, Rev. 1.03 456 PRELIMINARY Freescale Semiconductor When SPE = 1 Normal Mode SPC0 = 0 Serial Peripheral Interface (S12SPIV5) Table 15-11. Normal Mode and Bidirectional Mode Master Mode MSTR = 1 Slave Mode MSTR = 0 Serial Out SPI Serial In MOSI MISO Serial In SPI Serial Out MOSI MISO Bidirectional Mode SPC0 = 1 Serial Out SPI Serial In BIDIROE MOMI Serial In SPI Serial Out BIDIROE SISO The direction of each serial I/O pin depends on the BIDIROE bit. If the pin is configured as an output, serial data from the shift register is driven out on the pin. The same pin is also the serial input to the shift register. • The SCK is output for the master mode and input for the slave mode. • The SS is the input or output for the master mode, and it is always the input for the slave mode. • The bidirectional mode does not affect SCK and SS functions. NOTE In bidirectional master mode, with mode fault enabled, both data pins MISO and MOSI can be occupied by the SPI, though MOSI is normally used for transmissions in bidirectional mode and MISO is not used by the SPI. If a mode fault occurs, the SPI is automatically switched to slave mode. In this case MISO becomes occupied by the SPI and MOSI is not used. This must be considered, if the MISO pin is used for another purpose. 15.4.6 Error Conditions The SPI has one error condition: • Mode fault error 15.4.6.1 Mode Fault Error If the SS input becomes low while the SPI is configured as a master, it indicates a system error where more than one master may be trying to drive the MOSI and SCK lines simultaneously. This condition is not permitted in normal operation, the MODF bit in the SPI status register is set automatically, provided the MODFEN bit is set. In the special case where the SPI is in master mode and MODFEN bit is cleared, the SS pin is not used by the SPI. In this special case, the mode fault error function is inhibited and MODF remains cleared. In case S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 457 Serial Peripheral Interface (S12SPIV5) the SPI system is configured as a slave, the SS pin is a dedicated input pin. Mode fault error doesn’t occur in slave mode. If a mode fault error occurs, the SPI is switched to slave mode, with the exception that the slave output buffer is disabled. So SCK, MISO, and MOSI pins are forced to be high impedance inputs to avoid any possibility of conflict with another output driver. A transmission in progress is aborted and the SPI is forced into idle state. If the mode fault error occurs in the bidirectional mode for a SPI system configured in master mode, output enable of the MOMI (MOSI in bidirectional mode) is cleared if it was set. No mode fault error occurs in the bidirectional mode for SPI system configured in slave mode. The mode fault flag is cleared automatically by a read of the SPI status register (with MODF set) followed by a write to SPI control register 1. If the mode fault flag is cleared, the SPI becomes a normal master or slave again. NOTE If a mode fault error occurs and a received data byte is pending in the receive shift register, this data byte will be lost. 15.4.7 Low Power Mode Options 15.4.7.1 SPI in Run Mode In run mode with the SPI system enable (SPE) bit in the SPI control register clear, the SPI system is in a low-power, disabled state. SPI registers remain accessible, but clocks to the core of this module are disabled. 15.4.7.2 SPI in Wait Mode SPI operation in wait mode depends upon the state of the SPISWAI bit in SPI control register 2. • If SPISWAI is clear, the SPI operates normally when the CPU is in wait mode • If SPISWAI is set, SPI clock generation ceases and the SPI module enters a power conservation state when the CPU is in wait mode. – If SPISWAI is set and the SPI is configured for master, any transmission and reception in progress stops at wait mode entry. The transmission and reception resumes when the SPI exits wait mode. – If SPISWAI is set and the SPI is configured as a slave, any transmission and reception in progress continues if the SCK continues to be driven from the master. This keeps the slave synchronized to the master and the SCK. If the master transmits several bytes while the slave is in wait mode, the slave will continue to send out bytes consistent with the operation mode at the start of wait mode (i.e., if the slave is currently sending its SPIDR to the master, it will continue to send the same byte. Else if the slave is currently sending the last received byte from the master, it will continue to send each previous master byte). S12XS-Family Reference Manual, Rev. 1.03 458 PRELIMINARY Freescale Semiconductor Serial Peripheral Interface (S12SPIV5) NOTE Care must be taken when expecting data from a master while the slave is in wait or stop mode. Even though the shift register will continue to operate, the rest of the SPI is shut down (i.e., a SPIF interrupt will not be generated until exiting stop or wait mode). Also, the byte from the shift register will not be copied into the SPIDR register until after the slave SPI has exited wait or stop mode. In slave mode, a received byte pending in the receive shift register will be lost when entering wait or stop mode. An SPIF flag and SPIDR copy is generated only if wait mode is entered or exited during a tranmission. If the slave enters wait mode in idle mode and exits wait mode in idle mode, neither a SPIF nor a SPIDR copy will occur. 15.4.7.3 SPI in Stop Mode Stop mode is dependent on the system. The SPI enters stop mode when the module clock is disabled (held high or low). If the SPI is in master mode and exchanging data when the CPU enters stop mode, the transmission is frozen until the CPU exits stop mode. After stop, data to and from the external SPI is exchanged correctly. In slave mode, the SPI will stay synchronized with the master. The stop mode is not dependent on the SPISWAI bit. 15.4.7.4 Reset The reset values of registers and signals are described in Section 15.3, “Memory Map and Register Definition”, which details the registers and their bit fields. • If a data transmission occurs in slave mode after reset without a write to SPIDR, it will transmit garbage, or the data last received from the master before the reset. • Reading from the SPIDR after reset will always read zeros. 15.4.7.5 Interrupts The SPI only originates interrupt requests when SPI is enabled (SPE bit in SPICR1 set). The following is a description of how the SPI makes a request and how the MCU should acknowledge that request. The interrupt vector offset and interrupt priority are chip dependent. The interrupt flags MODF, SPIF, and SPTEF are logically ORed to generate an interrupt request. 15.4.7.5.1 MODF MODF occurs when the master detects an error on the SS pin. The master SPI must be configured for the MODF feature (see Table 15-3). After MODF is set, the current transfer is aborted and the following bit is changed: • MSTR = 0, The master bit in SPICR1 resets. The MODF interrupt is reflected in the status register MODF flag. Clearing the flag will also clear the interrupt. This interrupt will stay active while the MODF flag is set. MODF has an automatic clearing process which is described in Section 15.3.2.4, “SPI Status Register (SPISR)”. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 459 Serial Peripheral Interface (S12SPIV5) 15.4.7.5.2 SPIF SPIF occurs when new data has been received and copied to the SPI data register. After SPIF is set, it does not clear until it is serviced. SPIF has an automatic clearing process, which is described in Section 15.3.2.4, “SPI Status Register (SPISR)”. 15.4.7.5.3 SPTEF SPTEF occurs when the SPI data register is ready to accept new data. After SPTEF is set, it does not clear until it is serviced. SPTEF has an automatic clearing process, which is described in Section 15.3.2.4, “SPI Status Register (SPISR)”. S12XS-Family Reference Manual, Rev. 1.03 460 PRELIMINARY Freescale Semiconductor Chapter 16 Timer Module (TIM16B8CV2) Table 16-1. Revision History Table Rev. No. Date (Item No.) (Submitted By) Sections Affected Substantial Change(s) 02.00 02.01 02.02 02.03 15 Nov 2005 3 Aug 2006 03 Apr 2007 14 Sep.2007 16.3.2/16-465 Moved OCPD from offset $2F to $2C, updated OC7 diagram and memory map and regsiter description location for OCPD 16.3.2/16-465 Replaced TPORTE with OCPD, and added descriptionof OCPD 16.3.1/16-465 Removed redundant memory map table 16.4.3/16-484 Replaced typo OPCD with OCPD 16.1 Introduction The basic timer consists of a 16-bit, software-programmable counter driven by a enhanced programmable prescaler. This timer can be used for many purposes, including input waveform measurements while simultaneously generating an output waveform. Pulse widths can vary from microseconds to many seconds. This timer contains 8 complete input capture/output compare channels and one pulse accumulator. The input capture function is used to detect a selected transition edge and record the time. The output compare function is used for generating output signals or for timer software delays. The 16-bit pulse accumulator is used to operate as a simple event counter or a gated time accumulator. The pulse accumulator shares timer channel 7 when in event mode. A full access for the counter registers or the input capture/output compare registers should take place in one clock cycle. Accessing high byte and low byte separately for all of these registers may not yield the same result as accessing them in one word. 16.1.1 Features The TIM16B8CV2 includes these distinctive features: • Eight input capture/output compare channels. • Clock prescaling. • 16-bit counter. • 16-bit pulse accumulator. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 461 Timer Module (TIM16B8CV2) 16.1.2 Modes of Operation Stop: Freeze: Wait: Normal: Timer is off because clocks are stopped. Timer counter keep on running, unless TSFRZ in TSCR (0x0006) is set to 1. Counters keep on running, unless TSWAI in TSCR (0x0006) is set to 1. Timer counter keep on running, unless TEN in TSCR (0x0006) is cleared to 0. 16.1.3 Block Diagrams Bus clock Timer overflow interrupt Timer channel 0 interrupt Timer channel 7 interrupt PA overflow interrupt PA input interrupt Prescaler 16-bit Counter Registers 16-bit Pulse accumulator Channel 0 Input capture Output compare Channel 1 Input capture Output compare Channel 2 Input capture Output compare Channel 3 Input capture Output compare Channel 4 Input capture Output compare Channel 5 Input capture Output compare Channel 6 Input capture Output compare Channel 7 Input capture Output compare Figure 16-1. TIM16B8CV2 Block Diagram IOC0 IOC1 IOC2 IOC3 IOC4 IOC5 IOC6 IOC7 S12XS-Family Reference Manual, Rev. 1.03 462 PRELIMINARY Freescale Semiconductor Intermodule Bus PACLK / 65536 PACLK / 256 PACLK CLK1 CLK0 Prescaled clock (PCLK) Interrupt 4:1 MUX TIMCLK (Timer clock) Timer Module (TIM16B8CV2) Clock select (PAMOD) Edge detector PT7 PACNT MUX Divide by 64 M clock Figure 16-2. 16-Bit Pulse Accumulator Block Diagram PTn Edge detector 16-bit Main Timer TCn Input Capture Reg. Set CnF Interrupt Figure 16-3. Interrupt Flag Setting S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 463 Timer Module (TIM16B8CV2) PULSE ACCUMULATOR PAD CHANNEL 7 OUTPUT COMPARE OCPD TEN TIOS7 Figure 16-4. Channel 7 Output Compare/Pulse Accumulator Logic 16.2 External Signal Description The TIM16B8CV2 module has a total of eight external pins. 16.2.1 IOC7 — Input Capture and Output Compare Channel 7 Pin This pin serves as input capture or output compare for channel 7. This can also be configured as pulse accumulator input. 16.2.2 IOC6 — Input Capture and Output Compare Channel 6 Pin This pin serves as input capture or output compare for channel 6. 16.2.3 IOC5 — Input Capture and Output Compare Channel 5 Pin This pin serves as input capture or output compare for channel 5. 16.2.4 IOC4 — Input Capture and Output Compare Channel 4 Pin This pin serves as input capture or output compare for channel 4. Pin 16.2.5 IOC3 — Input Capture and Output Compare Channel 3 Pin This pin serves as input capture or output compare for channel 3. 16.2.6 IOC2 — Input Capture and Output Compare Channel 2 Pin This pin serves as input capture or output compare for channel 2. S12XS-Family Reference Manual, Rev. 1.03 464 PRELIMINARY Freescale Semiconductor Timer Module (TIM16B8CV2) 16.2.7 IOC1 — Input Capture and Output Compare Channel 1 Pin This pin serves as input capture or output compare for channel 1. 16.2.8 IOC0 — Input Capture and Output Compare Channel 0 Pin This pin serves as input capture or output compare for channel 0. NOTE For the description of interrupts see Section 16.6, “Interrupts”. 16.3 Memory Map and Register Definition This section provides a detailed description of all memory and registers. 16.3.1 Module Memory Map The memory map for the TIM16B8CV2 module is given below in Figure 16-5. The address listed for each register is the address offset. The total address for each register is the sum of the base address for the TIM16B8CV2 module and the address offset for each register. 16.3.2 Register Descriptions This section consists of register descriptions in address order. Each description includes a standard register diagram with an associated figure number. Details of register bit and field function follow the register diagrams, in bit order. Register Name Bit 7 6 5 4 3 2 1 Bit 0 0x0000 TIOS R IOS7 W IOS6 IOS5 IOS4 IOS3 IOS2 IOS1 IOS0 0x0001 CFORC 0x0002 OC7M 0x0003 OC7D 0x0004 TCNTH 0x0005 TCNTL R 0 W FOC7 0 FOC6 0 FOC5 0 FOC4 0 FOC3 0 FOC2 R OC7M7 W OC7M6 OC7M5 OC7M4 OC7M3 OC7M2 R OC7D7 W OC7D6 OC7D5 OC7D4 OC7D3 OC7D2 R TCNT15 TCNT14 TCNT13 TCNT12 TCNT11 TCNT10 W R TCNT7 W TCNT6 TCNT5 TCNT4 TCNT3 TCNT2 0 FOC1 OC7M1 OC7D1 TCNT9 TCNT1 0 FOC0 OC7M0 OC7D0 TCNT8 TCNT0 = Unimplemented or Reserved Figure 16-5. TIM16B8CV2 Register Summary S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 465 Timer Module (TIM16B8CV2) Register Name 0x0006 TSCR1 0x0007 TTOV 0x0008 TCTL1 0x0009 TCTL2 0x000A TCTL3 0x000B TCTL4 0x000C TIE 0x000D TSCR2 0x000E TFLG1 0x000F TFLG2 0x0010–0x001F TCxH–TCxL 0x0020 PACTL 0x0021 PAFLG 0x0022 PACNTH 0x0023 PACNTL 0x0024–0x002B Reserved Bit 7 6 5 4 3 2 1 Bit 0 R 0 0 0 TEN TSWAI TSFRZ TFFCA PRNT W R TOV7 W TOV6 TOV5 TOV4 TOV3 TOV2 TOV1 TOV0 R OM7 OL7 OM6 OL6 OM5 OL5 OM4 OL4 W R OM3 OL3 OM2 OL2 OM1 OL1 OM0 OL0 W R EDG7B W EDG7A EDG6B EDG6A EDG5B EDG5A EDG4B EDG4A R EDG3B W EDG3A EDG2B EDG2A EDG1B EDG1A EDG0B EDG0A R C7I C6I C5I C4I C3I C2I C1I C0I W R 0 0 0 TOI TCRE PR2 PR1 PR0 W R C7F C6F C5F C4F C3F C2F C1F C0F W R 0 0 0 0 0 0 0 TOF W R Bit 15 W Bit 14 Bit 13 Bit 12 Bit 11 Bit 10 Bit 9 Bit 8 R Bit 7 W Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 R 0 W PAEN PAMOD PEDGE CLK1 CLK0 PAOVI PAI R 0 0 0 0 0 0 PAOVF PAIF W R PACNT15 PACNT14 PACNT13 PACNT12 PACNT11 PACNT10 PACNT9 PACNT8 W R PACNT7 PACNT6 PACNT5 PACNT4 PACNT3 PACNT2 PACNT1 PACNT0 W R W = Unimplemented or Reserved Figure 16-5. TIM16B8CV2 Register Summary (continued) S12XS-Family Reference Manual, Rev. 1.03 466 PRELIMINARY Freescale Semiconductor Timer Module (TIM16B8CV2) Register Name 0x002C OCPD 0x002D Reserved 0x002E PTPSR 0x002F Reserved Bit 7 R OCPD7 W R 6 OCPD6 5 OCPD5 4 OCPD4 3 OCPD3 2 OCPD2 1 OCPD1 Bit 0 OCPD0 R PTPS7 W PTPS6 PTPS5 PTPS4 PTPS3 PTPS2 R W = Unimplemented or Reserved Figure 16-5. TIM16B8CV2 Register Summary (continued) PTPS1 PTPS0 16.3.2.1 Timer Input Capture/Output Compare Select (TIOS) Module Base + 0x0000 R W Reset 7 IOS7 0 6 IOS6 5 IOS5 4 IOS4 3 IOS3 2 IOS2 1 IOS1 0 0 0 0 0 0 Figure 16-6. Timer Input Capture/Output Compare Select (TIOS) Read: Anytime Write: Anytime Table 16-2. TIOS Field Descriptions Field 7:0 IOS[7:0] Description Input Capture or Output Compare Channel Configuration 0 The corresponding channel acts as an input capture. 1 The corresponding channel acts as an output compare. 0 IOS0 0 16.3.2.2 Timer Compare Force Register (CFORC) Module Base + 0x0001 R W Reset 7 0 FOC7 0 6 5 4 3 2 0 0 0 0 0 FOC6 FOC5 FOC4 FOC3 FOC2 0 0 0 0 0 Figure 16-7. Timer Compare Force Register (CFORC) Read: Anytime but will always return 0x0000 (1 state is transient) 1 0 FOC1 0 0 0 FOC0 0 S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 467 Timer Module (TIM16B8CV2) Write: Anytime Table 16-3. CFORC Field Descriptions Field Description 7:0 FOC[7:0] Force Output Compare Action for Channel 7:0 — A write to this register with the corresponding data bit(s) set causes the action which is programmed for output compare “x” to occur immediately. The action taken is the same as if a successful comparison had just taken place with the TCx register except the interrupt flag does not get set. Note: A successful channel 7 output compare overrides any channel 6:0 compares. If forced output compare on any channel occurs at the same time as the successful output compare then forced output compare action will take precedence and interrupt flag won’t get set. 16.3.2.3 Output Compare 7 Mask Register (OC7M) Module Base + 0x0002 R W Reset 7 OC7M7 0 Read: Anytime Write: Anytime 6 OC7M6 5 OC7M5 4 OC7M4 3 OC7M3 2 OC7M2 0 0 0 0 0 Figure 16-8. Output Compare 7 Mask Register (OC7M) 1 OC7M1 0 Table 16-4. OC7M Field Descriptions 0 OC7M0 0 Field Description 7:0 OC7M[7:0] Output Compare 7 Mask — Setting the OC7Mx (x ranges from 0 to 6) will set the corresponding port to be an output port when the corresponding TIOSx (x ranges from 0 to 6) bit is set to be an output compare and the corresponding OCPDx (x ranges from 0 to 6) bit is set to zero to enable the timer port. A successful channel 7 output compare overrides any channel 6:0 compares. For each OC7M bit that is set, the output compare action reflects the corresponding OC7D bit. 16.3.2.4 Output Compare 7 Data Register (OC7D) Module Base + 0x0003 R W Reset 7 OC7D7 0 Read: Anytime Write: Anytime 6 OC7D6 5 OC7D5 4 OC7D4 3 OC7D3 2 OC7D2 0 0 0 0 0 Figure 16-9. Output Compare 7 Data Register (OC7D) 1 OC7D1 0 0 OC7D0 0 S12XS-Family Reference Manual, Rev. 1.03 468 PRELIMINARY Freescale Semiconductor Timer Module (TIM16B8CV2) Table 16-5. OC7D Field Descriptions Field Description 7:0 Output Compare 7 Data — A channel 7 output compare can cause bits in the output compare 7 data register OC7D[7:0] to transfer to the timer port data register depending on the output compare 7 mask register. 16.3.2.5 Timer Count Register (TCNT) Module Base + 0x0004 R W Reset 15 TCNT15 0 14 TCNT14 13 TCNT13 12 TCNT12 11 TCNT11 10 TCNT10 0 0 0 0 0 Figure 16-10. Timer Count Register High (TCNTH) 9 TCNT9 0 9 TCNT8 0 Module Base + 0x0005 R W Reset 7 TCNT7 0 6 TCNT6 5 TCNT5 4 TCNT4 3 TCNT3 2 TCNT2 0 0 0 0 0 Figure 16-11. Timer Count Register Low (TCNTL) 1 TCNT1 0 0 TCNT0 0 The 16-bit main timer is an up counter. A full access for the counter register should take place in one clock cycle. A separate read/write for high byte and low byte will give a different result than accessing them as a word. Read: Anytime Write: Has no meaning or effect in the normal mode; only writable in special modes (test_mode = 1). The period of the first count after a write to the TCNT registers may be a different size because the write is not synchronized with the prescaler clock. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 469 Timer Module (TIM16B8CV2) 16.3.2.6 Timer System Control Register 1 (TSCR1) Module Base + 0x0006 7 6 5 4 3 2 1 0 R 0 0 0 TEN TSWAI TSFRZ TFFCA PRNT W Reset 0 0 0 0 0 0 0 0 = Unimplemented or Reserved Figure 16-12. Timer System Control Register 1 (TSCR2) Read: Anytime Write: Anytime Table 16-6. TSCR1 Field Descriptions Field 7 TEN 6 TSWAI 5 TSFRZ 4 TFFCA 3 PRNT Description Timer Enable 0 Disables the main timer, including the counter. Can be used for reducing power consumption. 1 Allows the timer to function normally. If for any reason the timer is not active, there is no ÷64 clock for the pulse accumulator because the ÷64 is generated by the timer prescaler. Timer Module Stops While in Wait 0 Allows the timer module to continue running during wait. 1 Disables the timer module when the MCU is in the wait mode. Timer interrupts cannot be used to get the MCU out of wait. TSWAI also affects pulse accumulator. Timer Stops While in Freeze Mode 0 Allows the timer counter to continue running while in freeze mode. 1 Disables the timer counter whenever the MCU is in freeze mode. This is useful for emulation. TSFRZ does not stop the pulse accumulator. Timer Fast Flag Clear All 0 Allows the timer flag clearing to function normally. 1 For TFLG1(0x000E), a read from an input capture or a write to the output compare channel (0x0010–0x001F) causes the corresponding channel flag, CnF, to be cleared. For TFLG2 (0x000F), any access to the TCNT register (0x0004, 0x0005) clears the TOF flag. Any access to the PACNT registers (0x0022, 0x0023) clears the PAOVF and PAIF flags in the PAFLG register (0x0021). This has the advantage of eliminating software overhead in a separate clear sequence. Extra care is required to avoid accidental flag clearing due to unintended accesses. Precision Timer 0 Enables legacy timer. PR0, PR1, and PR2 bits of the TSCR2 register are used for timer counter prescaler selection. 1 Enables precision timer. All bits of the PTPSR register are used for Precision Timer Prescaler Selection, and all bits. This bit is writable only once out of reset. S12XS-Family Reference Manual, Rev. 1.03 470 PRELIMINARY Freescale Semiconductor 16.3.2.7 Timer Toggle On Overflow Register 1 (TTOV) Timer Module (TIM16B8CV2) Module Base + 0x0007 R W Reset 7 TOV7 0 6 TOV6 5 TOV5 4 TOV4 3 TOV3 2 TOV2 1 TOV1 0 0 0 0 0 0 Figure 16-13. Timer Toggle On Overflow Register 1 (TTOV) 0 TOV0 0 Read: Anytime Write: Anytime Table 16-7. TTOV Field Descriptions Field 7:0 TOV[7:0] Description Toggle On Overflow Bits — TOVx toggles output compare pin on overflow. This feature only takes effect when in output compare mode. When set, it takes precedence over forced output compare but not channel 7 override events. 0 Toggle output compare pin on overflow feature disabled. 1 Toggle output compare pin on overflow feature enabled. 16.3.2.8 Timer Control Register 1/Timer Control Register 2 (TCTL1/TCTL2) Module Base + 0x0008 7 R OM7 W 6 OL7 5 OM6 4 OL6 3 OM5 2 OL5 1 OM4 0 OL4 Reset 0 0 0 0 0 0 0 0 Figure 16-14. Timer Control Register 1 (TCTL1) Module Base + 0x0009 7 R OM3 W 6 OL3 5 OM2 4 OL2 3 OM1 2 OL1 1 OM0 0 OL0 Reset 0 0 0 0 0 0 0 0 Figure 16-15. Timer Control Register 2 (TCTL2) Read: Anytime Write: Anytime S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 471 Timer Module (TIM16B8CV2) Field 7:0 OMx 7:0 OLx Table 16-8. TCTL1/TCTL2 Field Descriptions Description Output Mode — These eight pairs of control bits are encoded to specify the output action to be taken as a result of a successful OCx compare. When either OMx or OLx is 1, the pin associated with OCx becomes an output tied to OCx. Note: To enable output action by OMx bits on timer port, the corresponding bit in OC7M should be cleared. For an output line to be driven by an OCx the OCPDx must be cleared. Output Level — These eight pairs of control bits are encoded to specify the output action to be taken as a result of a successful OCx compare. When either OMx or OLx is 1, the pin associated with OCx becomes an output tied to OCx. Note: To enable output action by OLx bits on timer port, the corresponding bit in OC7M should be cleared. For an output line to be driven by an OCx the OCPDx must be cleared. Table 16-9. Compare Result Output Action OMx OLx 0 0 0 1 1 0 1 1 Action No output compare action on the timer output signal Toggle OCx output line Clear OCx output line to zero Set OCx output line to one To operate the 16-bit pulse accumulator independently of input capture or output compare 7 and 0 respectively the user must set the corresponding bits IOSx = 1, OMx = 0 and OLx = 0. OC7M7 in the OC7M register must also be cleared. S12XS-Family Reference Manual, Rev. 1.03 472 PRELIMINARY Freescale Semiconductor Timer Module (TIM16B8CV2) 16.3.2.9 Timer Control Register 3/Timer Control Register 4 (TCTL3 and TCTL4) Module Base + 0x000A R W Reset 7 EDG7B 0 6 EDG7A 5 EDG6B 4 EDG6A 3 EDG5B 2 EDG5A 0 0 0 0 0 Figure 16-16. Timer Control Register 3 (TCTL3) 1 EDG4B 0 0 EDG4A 0 Module Base + 0x000B R W Reset 7 EDG3B 0 Read: Anytime Write: Anytime. 6 EDG3A 5 EDG2B 4 EDG2A 3 EDG1B 2 EDG1A 0 0 0 0 0 Figure 16-17. Timer Control Register 4 (TCTL4) Table 16-10. TCTL3/TCTL4 Field Descriptions 1 EDG0B 0 0 EDG0A 0 Field 7:0 EDGnB EDGnA Description Input Capture Edge Control — These eight pairs of control bits configure the input capture edge detector circuits. Table 16-11. Edge Detector Circuit Configuration EDGnB 0 0 1 1 EDGnA 0 1 0 1 Configuration Capture disabled Capture on rising edges only Capture on falling edges only Capture on any edge (rising or falling) S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 473 Timer Module (TIM16B8CV2) 16.3.2.10 Timer Interrupt Enable Register (TIE) Module Base + 0x000C 7 6 5 4 3 2 1 0 R C7I C6I C5I C4I C3I C2I C1I C0I W Reset 0 0 0 0 0 0 0 0 Figure 16-18. Timer Interrupt Enable Register (TIE) Read: Anytime Write: Anytime. Table 16-12. TIE Field Descriptions Field 7:0 C7I:C0I Description Input Capture/Output Compare “x” Interrupt Enable — The bits in TIE correspond bit-for-bit with the bits in the TFLG1 status register. If cleared, the corresponding flag is disabled from causing a hardware interrupt. If set, the corresponding flag is enabled to cause a interrupt. 16.3.2.11 Timer System Control Register 2 (TSCR2) Module Base + 0x000D 7 6 5 4 3 2 1 0 R 0 0 0 TOI TCRE PR2 PR1 PR0 W Reset 0 0 0 0 0 0 0 0 = Unimplemented or Reserved Figure 16-19. Timer System Control Register 2 (TSCR2) Read: Anytime Write: Anytime. Table 16-13. TSCR2 Field Descriptions Field 7 TOI Description Timer Overflow Interrupt Enable 0 Interrupt inhibited. 1 Hardware interrupt requested when TOF flag set. S12XS-Family Reference Manual, Rev. 1.03 474 PRELIMINARY Freescale Semiconductor Timer Module (TIM16B8CV2) Table 16-13. TSCR2 Field Descriptions (continued) Field 3 TCRE 2 PR[2:0] Description Timer Counter Reset Enable — This bit allows the timer counter to be reset by a successful output compare 7 event. This mode of operation is similar to an up-counting modulus counter. 0 Counter reset inhibited and counter free runs. 1 Counter reset by a successful output compare 7. If TC7 = 0x0000 and TCRE = 1, TCNT will stay at 0x0000 continuously. If TC7 = 0xFFFF and TCRE = 1, TOF will never be set when TCNT is reset from 0xFFFF to 0x0000. Timer Prescaler Select — These three bits select the frequency of the timer prescaler clock derived from the Bus Clock as shown in Table 16-14. Table 16-14. Timer Clock Selection PR2 PR1 PR0 Timer Clock 0 0 0 Bus Clock / 1 0 0 1 Bus Clock / 2 0 1 0 Bus Clock / 4 0 1 1 Bus Clock / 8 1 0 0 Bus Clock / 16 1 0 1 Bus Clock / 32 1 1 0 Bus Clock / 64 1 1 1 Bus Clock / 128 NOTE The newly selected prescale factor will not take effect until the next synchronized edge where all prescale counter stages equal zero. 16.3.2.12 Main Timer Interrupt Flag 1 (TFLG1) Module Base + 0x000E 7 R C7F W 6 C6F 5 C5F 4 C4F 3 C3F 2 C2F 1 C1F 0 C0F Reset 0 0 0 0 0 0 0 0 Figure 16-20. Main Timer Interrupt Flag 1 (TFLG1) Read: Anytime Write: Used in the clearing mechanism (set bits cause corresponding bits to be cleared). Writing a zero will not affect current status of the bit. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 475 Timer Module (TIM16B8CV2) Table 16-15. TRLG1 Field Descriptions Field 7:0 C[7:0]F Description Input Capture/Output Compare Channel “x” Flag — These flags are set when an input capture or output compare event occurs. Clear a channel flag by writing one to it. When TFFCA bit in TSCR register is set, a read from an input capture or a write into an output compare channel (0x0010–0x001F) will cause the corresponding channel flag CxF to be cleared. 16.3.2.13 Main Timer Interrupt Flag 2 (TFLG2) Module Base + 0x000F 7 6 5 4 3 2 1 0 R 0 0 0 0 0 0 0 TOF W Reset 0 0 0 0 0 0 0 0 Unimplemented or Reserved Figure 16-21. Main Timer Interrupt Flag 2 (TFLG2) TFLG2 indicates when interrupt conditions have occurred. To clear a bit in the flag register, write the bit to one. Read: Anytime Write: Used in clearing mechanism (set bits cause corresponding bits to be cleared). Any access to TCNT will clear TFLG2 register if the TFFCA bit in TSCR register is set. Table 16-16. TRLG2 Field Descriptions Field 7 TOF Description Timer Overflow Flag — Set when 16-bit free-running timer overflows from 0xFFFF to 0x0000. This bit is cleared automatically by a write to the TFLG2 register with bit 7 set. (See also TCRE control bit explanation.) 16.3.2.14 Timer Input Capture/Output Compare Registers High and Low 0–7 (TCxH and TCxL) Module Base + 0x0010 = TC0H 0x0012 = TC1H 0x0014 = TC2H 0x0016 = TC3H 0x0018 = TC4H 0x001A = TC5H 0x001C = TC6H 0x001E = TC7H 15 R Bit 15 W 14 Bit 14 13 Bit 13 12 Bit 12 11 Bit 11 10 Bit 10 9 Bit 9 0 Bit 8 Reset 0 0 0 0 0 0 0 0 Figure 16-22. Timer Input Capture/Output Compare Register x High (TCxH) S12XS-Family Reference Manual, Rev. 1.03 476 PRELIMINARY Freescale Semiconductor Timer Module (TIM16B8CV2) Module Base + 0x0011 = TC0L 0x0013 = TC1L 0x0015 = TC2L 0x0017 = TC3L 0x0019 = TC4L 0x001B = TC5L 0x001D = TC6L 0x001F = TC7L 7 R Bit 7 W 6 Bit 6 5 Bit 5 4 Bit 4 3 Bit 3 2 Bit 2 1 Bit 1 0 Bit 0 Reset 0 0 0 0 0 0 0 0 Figure 16-23. Timer Input Capture/Output Compare Register x Low (TCxL) Depending on the TIOS bit for the corresponding channel, these registers are used to latch the value of the free-running counter when a defined transition is sensed by the corresponding input capture edge detector or to trigger an output action for output compare. Read: Anytime Write: Anytime for output compare function.Writes to these registers have no meaning or effect during input capture. All timer input capture/output compare registers are reset to 0x0000. NOTE Read/Write access in byte mode for high byte should takes place before low byte otherwise it will give a different result. 16.3.2.15 16-Bit Pulse Accumulator Control Register (PACTL) Module Base + 0x0020 7 R 0 W 6 5 4 3 2 1 0 PAEN PAMOD PEDGE CLK1 CLK0 PAOVI PAI Reset 0 0 0 0 0 0 0 0 Unimplemented or Reserved Figure 16-24. 16-Bit Pulse Accumulator Control Register (PACTL) When PAEN is set, the PACT is enabled.The PACT shares the input pin with IOC7. Read: Any time Write: Any time S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 477 Timer Module (TIM16B8CV2) Table 16-17. PACTL Field Descriptions Field 6 PAEN 5 PAMOD 4 PEDGE 3:2 CLK[1:0] 1 PAOVI 0 PAI Description Pulse Accumulator System Enable — PAEN is independent from TEN. With timer disabled, the pulse accumulator can function unless pulse accumulator is disabled. 0 16-Bit Pulse Accumulator system disabled. 1 Pulse Accumulator system enabled. Pulse Accumulator Mode — This bit is active only when the Pulse Accumulator is enabled (PAEN = 1). See Table 16-18. 0 Event counter mode. 1 Gated time accumulation mode. Pulse Accumulator Edge Control — This bit is active only when the Pulse Accumulator is enabled (PAEN = 1). For PAMOD bit = 0 (event counter mode). See Table 16-18. 0 Falling edges on IOC7 pin cause the count to be incremented. 1 Rising edges on IOC7 pin cause the count to be incremented. For PAMOD bit = 1 (gated time accumulation mode). 0 IOC7 input pin high enables M (bus clock) divided by 64 clock to Pulse Accumulator and the trailing falling edge on IOC7 sets the PAIF flag. 1 IOC7 input pin low enables M (bus clock) divided by 64 clock to Pulse Accumulator and the trailing rising edge on IOC7 sets the PAIF flag. Clock Select Bits — Refer to Table 16-19. Pulse Accumulator Overflow Interrupt Enable 0 Interrupt inhibited. 1 Interrupt requested if PAOVF is set. Pulse Accumulator Input Interrupt Enable 0 Interrupt inhibited. 1 Interrupt requested if PAIF is set. PAMOD 0 0 1 1 PEDGE 0 1 0 1 Table 16-18. Pin Action Pin Action Falling edge Rising edge Div. by 64 clock enabled with pin high level Div. by 64 clock enabled with pin low level NOTE If the timer is not active (TEN = 0 in TSCR), there is no divide-by-64 because the ÷64 clock is generated by the timer prescaler. S12XS-Family Reference Manual, Rev. 1.03 478 PRELIMINARY Freescale Semiconductor Timer Module (TIM16B8CV2) CLK1 0 0 1 1 Table 16-19. Timer Clock Selection CLK0 0 1 0 1 Timer Clock Use timer prescaler clock as timer counter clock Use PACLK as input to timer counter clock Use PACLK/256 as timer counter clock frequency Use PACLK/65536 as timer counter clock frequency For the description of PACLK please refer Figure 16-24. If the pulse accumulator is disabled (PAEN = 0), the prescaler clock from the timer is always used as an input clock to the timer counter. The change from one selected clock to the other happens immediately after these bits are written. 16.3.2.16 Pulse Accumulator Flag Register (PAFLG) Module Base + 0x0021 7 6 5 4 3 2 1 R 0 0 0 0 0 0 PAOVF W Reset 0 0 0 0 0 0 0 Unimplemented or Reserved Figure 16-25. Pulse Accumulator Flag Register (PAFLG) 0 PAIF 0 Read: Anytime Write: Anytime When the TFFCA bit in the TSCR register is set, any access to the PACNT register will clear all the flags in the PAFLG register. Table 16-20. PAFLG Field Descriptions Field 1 PAOVF 0 PAIF Description Pulse Accumulator Overflow Flag — Set when the 16-bit pulse accumulator overflows from 0xFFFF to 0x0000. This bit is cleared automatically by a write to the PAFLG register with bit 1 set. Pulse Accumulator Input edge Flag — Set when the selected edge is detected at the IOC7 input pin.In event mode the event edge triggers PAIF and in gated time accumulation mode the trailing edge of the gate signal at the IOC7 input pin triggers PAIF. This bit is cleared by a write to the PAFLG register with bit 0 set. Any access to the PACNT register will clear all the flags in this register when TFFCA bit in register TSCR(0x0006) is set. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 479 Timer Module (TIM16B8CV2) 16.3.2.17 Pulse Accumulators Count Registers (PACNT) Module Base + 0x0022 15 R PACNT15 W 14 PACNT14 13 PACNT13 12 PACNT12 11 PACNT11 10 PACNT10 9 PACNT9 Reset 0 0 0 0 0 0 0 Figure 16-26. Pulse Accumulator Count Register High (PACNTH) 0 PACNT8 0 Module Base + 0x0023 R W Reset 7 PACNT7 0 6 PACNT6 5 PACNT5 4 PACNT4 3 PACNT3 2 PACNT2 1 PACNT1 0 0 0 0 0 0 Figure 16-27. Pulse Accumulator Count Register Low (PACNTL) 0 PACNT0 0 Read: Anytime Write: Anytime These registers contain the number of active input edges on its input pin since the last reset. When PACNT overflows from 0xFFFF to 0x0000, the Interrupt flag PAOVF in PAFLG (0x0021) is set. Full count register access should take place in one clock cycle. A separate read/write for high byte and low byte will give a different result than accessing them as a word. NOTE Reading the pulse accumulator counter registers immediately after an active edge on the pulse accumulator input pin may miss the last count because the input has to be synchronized with the bus clock first. 16.3.2.18 Output Compare Pin Disconnect Register(OCPD) Module Base + 0x002C R W Reset 7 OCPD7 0 Read: Anytime 6 OCPD6 5 OCPD5 4 OCPD4 3 OCPD3 2 OCPD2 1 OCPD1 0 0 0 0 0 0 Figure 16-28. Ouput Compare Pin Disconnect Register (OCPD) Write: Anytime All bits reset to zero. 0 OCPD0 0 S12XS-Family Reference Manual, Rev. 1.03 480 PRELIMINARY Freescale Semiconductor Timer Module (TIM16B8CV2) Field Description OCPD[7:0} Output Compare Pin Disconnect Bits 0 Enables the timer channel port. Ouptut Compare action will occur on the channel pin. These bits do not affect the input capture or pulse accumulator functions 1 Disables the timer channel port. Output Compare action will not occur on the channel pin, but the output compare flag still become set . 16.3.2.19 Precision Timer Prescaler Select Register (PTPSR) Module Base + 0x002E R W Reset 7 PTPS7 0 Read: Anytime 6 PTPS6 5 PTPS5 4 PTPS4 3 PTPS3 2 PTPS2 1 PTPS1 0 0 0 0 0 0 Figure 16-29. Precision Timer Prescaler Select Register (PTPSR) Write: Anytime All bits reset to zero. Table 16-21. PTPSR Field Descriptions 0 PTPS0 0 Field Description 7:0 PTPS[7:0] Precision Timer Prescaler Select Bits — These eight bits specify the division rate of the main Timer prescaler. These are effective only when the PRNT bit of TSCR1 is set to 1. Table 16-22 shows some selection examples in this case. The newly selected prescale factor will not take effect until the next synchronized edge where all prescale counter stages equal zero. PTPS7 0 0 0 0 0 0 0 0 0 0 0 Table 16-22. Precision Timer Prescaler Selection Examples when PRNT = 1 PTPS6 0 0 0 0 0 0 0 0 0 0 0 PTPS5 0 0 0 0 0 0 0 0 0 0 1 PTPS4 0 0 0 0 0 0 0 0 0 1 1 PTPS3 0 0 0 0 0 0 0 0 1 1 1 PTPS2 0 0 0 0 1 1 1 1 1 1 1 PTPS1 0 0 1 1 0 0 1 1 1 1 1 PTPS0 0 1 0 1 0 1 0 1 1 1 1 Prescale Factor 1 2 3 4 5 6 7 8 16 32 64 S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 481 Timer Module (TIM16B8CV2) Table 16-22. Precision Timer Prescaler Selection Examples when PRNT = 1 PTPS7 0 1 PTPS6 1 1 PTPS5 1 1 PTPS4 1 1 PTPS3 1 1 PTPS2 1 1 PTPS1 1 1 PTPS0 1 1 Prescale Factor 128 256 16.4 Functional Description This section provides a complete functional description of the timer TIM16B8CV2 block. Please refer to the detailed timer block diagram in Figure 16-30 as necessary. S12XS-Family Reference Manual, Rev. 1.03 482 PRELIMINARY Freescale Semiconductor Timer Module (TIM16B8CV2) Bus Clock PR[2:1:0] PRESCALER PACLK PACLK/256 PACLK/65536 CLK[1:0] MUX channel 7 output compare TCRE TCNT(hi):TCNT(lo) 16-BIT COUNTER CHANNEL 0 16-BIT COMPARATOR TC0 EDG0A EDG0B CHANNEL 1 16-BIT COMPARATOR TC1 EDG1A EDG1B CHANNEL2 CLEAR COUNTER TE C0F EDGE DETECT OM:OL0 TOV0 C1F EDGE DETECT OM:OL1 TOV1 CxI CxF TOF TOI INTERRUPT LOGIC TOF C0F IOC0 C1F IOC1 CH. 0 CAPTURE IOC0 PIN LOGIC CH. 0COMPARE IOC0 PIN CH. 1 CAPTURE IOC1 PIN LOGIC CH. 1 COMPARE IOC1 PIN CHANNEL7 16-BIT COMPARATOR TC7 EDG7A EDG7B C7F EDGE DETECT OM:O73 TOV7 C7F IOC7 PAOVF PACNT(hi):PACNT(lo) PACLK/65536 PACLK/256 16-BIT COUNTER PACLK INTERRUPT REQUEST INTERRUPT LOGIC PAOVI PAOVF PAI PAIF PEDGE PAE PAMOD DIVIDE-BY-64 CH.7 CAPTURE IOC7 PIN PA INPUT LOGIC IOC7 PIN CH. 7 COMPARE EDGE DETECT PAIF Bus Clock PAOVF PAOVI Figure 16-30. Detailed Timer Block Diagram 16.4.1 Prescaler The prescaler divides the bus clock by 1,2,4,8,16,32,64 or 128. The prescaler select bits, PR[2:0], select the prescaler divisor. PR[2:0] are in timer system control register 2 (TSCR2). S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 483 Timer Module (TIM16B8CV2) The prescaler divides the bus clock by a prescalar value. Prescaler select bits PR[2:0] of in timer system control register 2 (TSCR2) are set to define a prescalar value that generates a divide by 1, 2, 4, 8, 16, 32, 64 and 128 when the PRNT bit in TSCR1 is disabled. By enabling the PRNT bit of the TSCR1 register, the performance of the timer can be enhanced. In this case, it is possible to set additional prescaler settings for the main timer counter in the present timer by using PTPSR[7:0] bits of PTPSR register. 16.4.2 Input Capture Clearing the I/O (input/output) select bit, IOSx, configures channel x as an input capture channel. The input capture function captures the time at which an external event occurs. When an active edge occurs on the pin of an input capture channel, the timer transfers the value in the timer counter into the timer channel registers, TCx. The minimum pulse width for the input capture input is greater than two bus clocks. An input capture on channel x sets the CxF flag. The CxI bit enables the CxF flag to generate interrupt requests. 16.4.3 Output Compare Setting the I/O select bit, IOSx, configures channel x as an output compare channel. The output compare function can generate a periodic pulse with a programmable polarity, duration, and frequency. When the timer counter reaches the value in the channel registers of an output compare channel, the timer can set, clear, or toggle the channel pin if the corresponding OCPDx bit is set to zero. An output compare on channel x sets the CxF flag. The CxI bit enables the CxF flag to generate interrupt requests. The output mode and level bits, OMx and OLx, select set, clear, toggle on output compare. Clearing both OMx and OLx results in no output compare action on the output compare channel pin. Setting a force output compare bit, FOCx, causes an output compare on channel x. A forced output compare does not set the channel flag. A successful output compare on channel 7 overrides output compares on all other output compare channels. The output compare 7 mask register masks the bits in the output compare 7 data register. The timer counter reset enable bit, TCRE, enables channel 7 output compares to reset the timer counter. A channel 7 output compare can reset the timer counter even if the IOC7 pin is being used as the pulse accumulator input. Writing to the timer port bit of an output compare pin does not affect the pin state. The value written is stored in an internal latch. When the pin becomes available for general-purpose output, the last value written to the bit appears at the pin. 16.4.3.1 OC Channel Initialization Internal register whose output drives OCx can be programmed before timer drives OCx. The desired state can be programmed to this Internal register by writing a one to CFORCx bit with TIOSx, OCPDx and TEN S12XS-Family Reference Manual, Rev. 1.03 484 PRELIMINARY Freescale Semiconductor Timer Module (TIM16B8CV2) bits set to one. Setting OCPDx to zero allows Interal register to drive the programmed state to OCx. This allows a glitch free switch over of port from general purpose I/O to timer output once the OCPDx bit is set to zero. 16.4.4 Pulse Accumulator The pulse accumulator (PACNT) is a 16-bit counter that can operate in two modes: Event counter mode — Counting edges of selected polarity on the pulse accumulator input pin, PAI. Gated time accumulation mode — Counting pulses from a divide-by-64 clock. The PAMOD bit selects the mode of operation. The minimum pulse width for the PAI input is greater than two bus clocks. 16.4.5 Event Counter Mode Clearing the PAMOD bit configures the PACNT for event counter operation. An active edge on the IOC7 pin increments the pulse accumulator counter. The PEDGE bit selects falling edges or rising edges to increment the count. NOTE The PACNT input and timer channel 7 use the same pin IOC7. To use the IOC7, disconnect it from the output logic by clearing the channel 7 output mode and output level bits, OM7 and OL7. Also clear the channel 7 output compare 7 mask bit, OC7M7. The Pulse Accumulator counter register reflect the number of active input edges on the PACNT input pin since the last reset. The PAOVF bit is set when the accumulator rolls over from 0xFFFF to 0x0000. The pulse accumulator overflow interrupt enable bit, PAOVI, enables the PAOVF flag to generate interrupt requests. NOTE The pulse accumulator counter can operate in event counter mode even when the timer enable bit, TEN, is clear. 16.4.6 Gated Time Accumulation Mode Setting the PAMOD bit configures the pulse accumulator for gated time accumulation operation. An active level on the PACNT input pin enables a divided-by-64 clock to drive the pulse accumulator. The PEDGE bit selects low levels or high levels to enable the divided-by-64 clock. The trailing edge of the active level at the IOC7 pin sets the PAIF. The PAI bit enables the PAIF flag to generate interrupt requests. The pulse accumulator counter register reflect the number of pulses from the divided-by-64 clock since the last reset. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 485 Timer Module (TIM16B8CV2) NOTE The timer prescaler generates the divided-by-64 clock. If the timer is not active, there is no divided-by-64 clock. 16.5 Resets The reset state of each individual bit is listed within Section 16.3, “Memory Map and Register Definition” which details the registers and their bit fields. 16.6 Interrupts This section describes interrupts originated by the TIM16B8CV2 block. Table 16-23 lists the interrupts generated by the TIM16B8CV2 to communicate with the MCU. Table 16-23. TIM16B8CV1 Interrupts Interrupt Offset1 Vector1 Priority1 Source Description C[7:0]F — — — Timer Channel 7–0 Active high timer channel interrupts 7–0 PAOVI — — — Pulse Accumulator Active high pulse accumulator input interrupt Input PAOVF — — — Pulse Accumulator Overflow Pulse accumulator overflow interrupt TOF — — — Timer Overflow 1 Chip Dependent. Timer Overflow interrupt The TIM16B8CV2 uses a total of 11 interrupt vectors. The interrupt vector offsets and interrupt numbers are chip dependent. 16.6.1 Channel [7:0] Interrupt (C[7:0]F) This active high outputs will be asserted by the module to request a timer channel 7 – 0 interrupt to be serviced by the system controller. 16.6.2 Pulse Accumulator Input Interrupt (PAOVI) This active high output will be asserted by the module to request a timer pulse accumulator input interrupt to be serviced by the system controller. 16.6.3 Pulse Accumulator Overflow Interrupt (PAOVF) This active high output will be asserted by the module to request a timer pulse accumulator overflow interrupt to be serviced by the system controller. 16.6.4 Timer Overflow Interrupt (TOF) This active high output will be asserted by the module to request a timer overflow interrupt to be serviced by the system controller. S12XS-Family Reference Manual, Rev. 1.03 486 PRELIMINARY Freescale Semiconductor Timer Module (TIM16B8CV2) S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 487 Timer Module (TIM16B8CV2) S12XS-Family Reference Manual, Rev. 1.03 488 PRELIMINARY Freescale Semiconductor Chapter 17 Voltage Regulator (S12VREGL3V3V1) Rev. No. Date (Item No.) (Submitted By) V01.02 V01.03 V01.04 09 Sep 2005 23 Sep 2005 08 Jun 2007 Table 17-1. Revision History Table Sections Affected Substantial Change(s) Updates for API external access and LVR flags. VAE reset value is 1. Added temperature sensor to customer information 17.1 Introduction Module VREG_3V3 is a tri output voltage regulator that provides two separate 1.84V (typical) supplies differing in the amount of current that can be sourced and a 2.82V (typical) supply. The regulator input voltage range is from 3.3V up to 5V (typical). 17.1.1 Features Module VREG_3V3 includes these distinctive features: • Three parallel, linear voltage regulators with bandgap reference • Low-voltage detect (LVD) with low-voltage interrupt (LVI) • Power-on reset (POR) • Low-voltage reset (LVR) • High Temperature Detect (HTD) with High Temperature Interrupt (HTI) • Autonomous periodical interrupt (API) 17.1.2 Modes of Operation There are three modes VREG_3V3 can operate in: 1. Full performance mode (FPM) (MCU is not in stop mode) The regulator is active, providing the nominal supply voltages with full current sourcing capability. Features LVD (low-voltage detect), LVR (low-voltage reset), and POR (power-on reset) and HTD (High Temperature Detect) are available. The API is available. 2. Reduced power mode (RPM) (MCU is in stop mode) The purpose is to reduce power consumption of the device. The output voltage may degrade to a lower value than in full performance mode, additionally the current sourcing capability is substantially reduced. Only the POR is available in this mode, LVD, LVR and HTD are disabled. The API is available. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 489 Voltage Regulator (S12VREGL3V3V1) 3. Shutdown mode Controlled by VREGEN (see device level specification for connectivity of VREGEN). This mode is characterized by minimum power consumption. The regulator outputs are in a highimpedance state, only the POR feature is available, LVD, LVR and HTD are disabled. The API internal RC oscillator clock is not available. This mode must be used to disable the chip internal regulator VREG_3V3, i.e., to bypass the VREG_3V3 to use external supplies. 17.1.3 Block Diagram Figure 17-1 shows the function principle of VREG_3V3 by means of a block diagram. The regulator core REG consists of three parallel subblocks, REG1, REG2 and REG3, providing three independent output voltages. S12XS-Family Reference Manual, Rev. 1.03 490 PRELIMINARY Freescale Semiconductor VDDR VDDA VSSA VDDX Voltage Regulator (S12VREGL3V3V1) Figure 17-1. VREG_3V3 Block Diagram VBG REG3 REG REG2 REG1 LVD LVR LVR POR VDDPLL VSSPLL VDDF VDD VSS POR VREGEN Bus Clock CTRL API Rate Select C HTD HTI LVI API API LVD: Low Voltage Detect LVR: Low Voltage Reset POR: Power-on Reset HTD: High Temperature Detect REG: Regulator Core CTRL: Regulator Control API: Auto. Periodical Interrupt PIN S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 491 Voltage Regulator (S12VREGL3V3V1) 17.2 External Signal Description Due to the nature of VREG_3V3 being a voltage regulator providing the chip internal power supply voltages, most signals are power supply signals connected to pads. Table 17-2 shows all signals of VREG_3V3 associated with pins. Table 17-2. Signal Properties Name VDDR VDDA VSSA VDDX VDD VSS VDDF VDDPLL VSSPLL VREGEN (optional) VREG_API (optional) Function Power input (positive supply) Quiet input (positive supply) Quiet input (ground) Power input (positive supply) Primary output (positive supply) Primary output (ground) Secondary output (positive supply) Tertiary output (positive supply) Tertiary output (ground) Optional Regulator Enable VREG Autonomous Periodical Interrupt output Reset State — — — — — — — — — — — Pull Up — — — — — — — — — — — NOTE Check device level specification for connectivity of the signals. 17.2.1 VDDR — Regulator Power Input Pins Signal VDDR is the power input of VREG_3V3. All currents sourced into the regulator loads flow through this pin. A chip external decoupling capacitor (100 nF...220 nF, X7R ceramic) between VDDR and VSSR (if VSSR is not available VSS) can smooth ripple on VDDR. For entering Shutdown Mode, pin VDDR should also be tied to ground on devices without VREGEN pin. 17.2.2 VDDA, VSSA — Regulator Reference Supply Pins Signals VDDA/VSSA, which are supposed to be relatively quiet, are used to supply the analog parts of the regulator. Internal precision reference circuits are supplied from these signals. A chip external decoupling capacitor (100 nF...220 nF, X7R ceramic) between VDDA and VSSA can further improve the quality of this supply. 17.2.3 VDD, VSS — Regulator Output1 (Core Logic) Pins Signals VDD/VSS are the primary outputs of VREG_3V3 that provide the power supply for the core logic. These signals are connected to device pins to allow external decoupling capacitors (220 nF, X7R ceramic). S12XS-Family Reference Manual, Rev. 1.03 492 PRELIMINARY Freescale Semiconductor Voltage Regulator (S12VREGL3V3V1) In Shutdown Mode an external supply driving VDD/VSS can replace the voltage regulator. 17.2.4 VDDF — Regulator Output2 (NVM Logic) Pins Signals VDDF/VSS are the secondary outputs of VREG_3V3 that provide the power supply for the NVM logic. These signals are connected to device pins to allow external decoupling capacitors (220 nF, X7R ceramic). In Shutdown Mode an external supply driving VDDF/VSS can replace the voltage regulator. 17.2.5 VDDPLL, VSSPLL — Regulator Output3 (PLL) Pins Signals VDDPLL/VSSPLL are the secondary outputs of VREG_3V3 that provide the power supply for the PLL and oscillator. These signals are connected to device pins to allow external decoupling capacitors (100 nF...220 nF, X7R ceramic). In Shutdown Mode, an external supply driving VDDPLL/VSSPLL can replace the voltage regulator. 17.2.6 VDDX — Power Input Pin Signals VDDX/VSS are monitored by VREG_3V3 with the LVR feature. 17.2.7 VREGEN — Optional Regulator Enable Pin This optional signal is used to shutdown VREG_3V3. In that case, VDD/VSS and VDDPLL/VSSPLL must be provided externally. Shutdown mode is entered with VREGEN being low. If VREGEN is high, the VREG_3V3 is either in Full Performance Mode or in Reduced Power Mode. For the connectivity of VREGEN, see device specification. NOTE Switching from FPM or RPM to shutdown of VREG_3V3 and vice versa is not supported while MCU is powered. 17.2.8 VREG_API — Optional Autonomous Periodical Interrupt Output Pin This pin provides the signal selected via APIEA if system is set accordingly. See 17.3.2.3, “Autonomous Periodical Interrupt Control Register (VREGAPICL) and 17.4.8, “Autonomous Periodical Interrupt (API) for details. For the connectivity of VREG_API, see device specification. 17.3 Memory Map and Register Definition This section provides a detailed description of all registers accessible in VREG_3V3. If enabled in the system, the VREG_3V3 will abort all read and write accesses to reserved registers within it’s memory slice. See device level specification for details. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 493 Voltage Regulator (S12VREGL3V3V1) 17.3.1 Module Memory Map A summary of the registers associated with the VREG_3V3 sub-block is shown in Table 17-3. Detailed descriptions of the registers and bits are given in the subsections that follow Address Name R 0x02F0 VREGHTCL W Bit 7 0 6 5 4 3 2 1 Bit 0 0 HTDS VSEL VAE HTEN HTIE HTIF R 0 0 0 0 0 LVDS 0x02F1 VREGCTRL LVIE LVIF W 0x02F2 VREGAPIC R L W APICLK 0 0 APIFES APIEA APIFE APIE APIF 0x02F3 VREGAPIT R R W APITR5 APITR4 APITR3 APITR2 APITR1 APITR0 0 0 0x02F4 VREGAPIR R H W APIR15 APIR14 APIR13 APIR12 APIR11 APIR10 APIR9 APIR8 0x02F5 VREGAPIR R L W APIR7 APIR6 APIR5 APIR4 APIR3 APIR2 APIR1 APIR0 0x02F6 Reserved R 06 W 0 0 0 0 0 0 0 0 R 0x02F7 VREGHTTR HTOEN W 0 0 0 HTTR3 Table 17-3. Register Summary HTTR2 HTTR1 HTTR0 S12XS-Family Reference Manual, Rev. 1.03 494 PRELIMINARY Freescale Semiconductor Voltage Regulator (S12VREGL3V3V1) 17.3.2 Register Descriptions This section describes all the VREG_3V3 registers and their individual bits. 17.3.2.1 High Temperature Control Register (VREGHTCL) The VREGHTCL register allows to configure the VREG temperature sense features. 0x02F0 7 R 0 W 6 5 4 3 2 1 0 0 HTDS VSEL VAE HTEN HTIE HTIF Reset 0 0 0 1 0 0 0 0 = Unimplemented or Reserved Table 17-4. VREGHTCL Field Descriptions Field 7, 6 Reserved 5 VSEL 4 VAE 3 HTEN 2 HTDS 1 HTIE 0 HTIF Description These reserved bits are used for test purposes and writable only in special modes. They must remain clear for correct temperature sensor operation. Voltage Access Select Bit — If set, the bandgap reference voltage VBG can be accessed internally (i.e. multiplexed to an internal Analog to Digital Converter channel). The internal access must be enabled by bit VAE. See device level specification for connectivity. 0 An internal temperature proportional voltage VHT can be accessed internally if VAE is set. 1 Bandgap reference voltage VBG can be accessed internally if VAE is set. Voltage Access Enable Bit — If set, the voltage selected by bit VSEL can be accessed internally (i.e. multiplexed to an internal Analog to Digital Converter channel). See device level specification for connectivity. 0 Voltage selected by VSEL can not be accessed internally (i.e. External analog input is connected to Analog to Digital Converter channel). 1 Voltage selected by VSEL can be accessed internally. High Temperature Enable Bit — If set the temperature sense is enabled. 0 The temperature sense is disabled. 1 The temperature sense is enabled. High Temperature Detect Status Bit — This read-only status bit reflects the temperature status. Writes have no effect. 0 Temperature TDIE is below level THTID or RPM or Shutdown Mode. 1 Temperature TDIE is above level THTIA and FPM. High Temperature Interrupt Enable Bit 0 Interrupt request is disabled. 1 Interrupt will be requested whenever HTIF is set. High Temperature Interrupt Flag — HTIF — High Temperature Interrupt Flag HTIF is set to 1 when HTDS status bit changes. This flag can only be cleared by writing a 1.}Writing a 0 has no effect. If enabled (HTIE=1), HTIF causes an interrupt request. 0 No change in HTDS bit. 1 HTDS bit has changed. Note: On entering the reduced power mode the HTIF is not cleared by the VREG. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 495 Voltage Regulator (S12VREGL3V3V1) 17.3.2.2 Control Register (VREGCTRL) The VREGCTRL register allows the configuration of the VREG_3V3 low-voltage detect features. 0x02F1 7 6 5 4 R 0 0 0 0 W Reset 0 0 0 0 = Unimplemented or Reserved 3 2 1 0 0 LVDS LVIE LVIF 0 0 0 0 Figure 17-2. Control Register (VREGCTRL) Table 17-5. VREGCTRL Field Descriptions Field 2 LVDS 1 LVIE 0 LVIF Description Low-Voltage Detect Status Bit — This read-only status bit reflects the input voltage. Writes have no effect. 0 Input voltage VDDA is above level VLVID or RPM or shutdown mode. 1 Input voltage VDDA is below level VLVIA and FPM. Low-Voltage Interrupt Enable Bit 0 Interrupt request is disabled. 1 Interrupt will be requested whenever LVIF is set. Low-Voltage Interrupt Flag — LVIF is set to 1 when LVDS status bit changes. This flag can only be cleared by writing a 1. Writing a 0 has no effect. If enabled (LVIE = 1), LVIF causes an interrupt request. 0 No change in LVDS bit. 1 LVDS bit has changed. Note: On entering the Reduced Power Mode the LVIF is not cleared by the VREG_3V3. S12XS-Family Reference Manual, Rev. 1.03 496 PRELIMINARY Freescale Semiconductor Voltage Regulator (S12VREGL3V3V1) 17.3.2.3 Autonomous Periodical Interrupt Control Register (VREGAPICL) The VREGAPICL register allows the configuration of the VREG_3V3 autonomous periodical interrupt features. 0x02F2 R W Reset 7 6 0 APICLK 5 4 3 2 1 0 APIES APIEA APIFE APIE 0 0 0 0 0 0 0 = Unimplemented or Reserved Figure 17-3. Autonomous Periodical Interrupt Control Register (VREGAPICL) 0 APIF 0 Table 17-6. VREGAPICL Field Descriptions Field 7 APICLK 4 APIES 3 APIEA 2 APIFE 1 APIE 0 APIF Description Autonomous Periodical Interrupt Clock Select Bit — Selects the clock source for the API. Writable only if APIFE = 0; APICLK cannot be changed if APIFE is set by the same write operation. 0 Autonomous periodical interrupt clock used as source. 1 Bus clock used as source. Autonomous Periodical Interrupt External Select Bit — Selects the waveform at the external pin.If set, at the external pin a clock is visible with 2 times the selected API Period (Table 17-10). If not set, at the external pin will be a high pulse at the end of every selected period with the size of half of the min period (Table 17-10). See device level specification for connectivity. 0 At the external periodic high pulses are visible, if APIEA and APIFE is set. 1 At the external pin a clock is visible, if APIEA and APIFE is set. Autonomous Periodical Interrupt External Access Enable Bit — If set, the waveform selected by bit APIES can be accessed externally. See device level specification for connectivity. 0 Waveform selected by APIES can not be accessed externally. 1 Waveform selected by APIES can be accessed externally, if APIFE is set. Autonomous Periodical Interrupt Feature Enable Bit — Enables the API feature and starts the API timer when set. 0 Autonomous periodical interrupt is disabled. 1 Autonomous periodical interrupt is enabled and timer starts running. Autonomous Periodical Interrupt Enable Bit 0 API interrupt request is disabled. 1 API interrupt will be requested whenever APIF is set. Autonomous Periodical Interrupt Flag — APIF is set to 1 when the in the API configured time has elapsed. This flag can only be cleared by writing a 1 to it. Clearing of the flag has precedence over setting. Writing a 0 has no effect. If enabled (APIE = 1), APIF causes an interrupt request. 0 API timeout has not yet occurred. 1 API timeout has occurred. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 497 Voltage Regulator (S12VREGL3V3V1) 17.3.2.4 Autonomous Periodical Interrupt Trimming Register (VREGAPITR) The VREGAPITR register allows to trim the API timeout period. 0x02F3 7 6 5 4 3 2 1 0 R 0 0 APITR5 APITR4 APITR3 APITR2 APITR1 APITR0 W Reset 01 01 01 01 01 01 0 0 1. Reset value is either 0 or preset by factory. See Section 1 (Device Overview) for details. = Unimplemented or Reserved Figure 17-4. Autonomous Periodical Interrupt Trimming Register (VREGAPITR) Table 17-7. VREGAPITR Field Descriptions Field Description 7–2 Autonomous Periodical Interrupt Period Trimming Bits — See Table 17-8 for trimming effects. APITR[5:0] Table 17-8. Trimming Effect of APIT Bit APITR[5] APITR[4] APITR[3] APITR[2] APITR[1] APITR[0] Trimming Effect Increases period Decreases period less than APITR[5] increased it Decreases period less than APITR[4] Decreases period less than APITR[3] Decreases period less than APITR[2] Decreases period less than APITR[1] S12XS-Family Reference Manual, Rev. 1.03 498 PRELIMINARY Freescale Semiconductor Voltage Regulator (S12VREGL3V3V1) 17.3.2.5 Autonomous Periodical Interrupt Rate High and Low Register (VREGAPIRH / VREGAPIRL) The VREGAPIRH and VREGAPIRL register allows the configuration of the VREG_3V3 autonomous periodical interrupt rate. 0x02F4 R W Reset 7 APIR15 6 APIR14 5 APIR13 4 APIR12 3 APIR11 2 APIR10 1 APIR9 0 0 0 0 0 0 0 = Unimplemented or Reserved Figure 17-5. Autonomous Periodical Interrupt Rate High Register (VREGAPIRH) 0 APIR8 0 0x02F5 R W Reset 7 APIR7 6 APIR6 5 APIR5 4 APIR4 3 APIR3 2 APIR2 1 APIR1 0 0 0 0 0 0 0 Figure 17-6. Autonomous Periodical Interrupt Rate Low Register (VREGAPIRL) 0 APIR0 0 Table 17-9. VREGAPIRH / VREGAPIRL Field Descriptions Field Description 15-0 Autonomous Periodical Interrupt Rate Bits — These bits define the timeout period of the API. See Table 17- APIR[15:0] 10 for details of the effect of the autonomous periodical interrupt rate bits. Writable only if APIFE = 0 of VREGAPICL register. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 499 Voltage Regulator (S12VREGL3V3V1) Table 17-10. Selectable Autonomous Periodical Interrupt Periods APICLK APIR[15:0] Selected Period 0 0000 0 0001 0 0002 0 0003 0 0004 0 0005 0.2 ms1 0.4 ms1 0.6 ms1 0.8 ms1 1.0 ms1 1.2 ms1 0 ..... 0 FFFD 0 FFFE 0 FFFF ..... 13106.8 ms1 13107.0 ms1 13107.2 ms1 1 0000 2 * bus clock period 1 0001 4 * bus clock period 1 0002 6 * bus clock period 1 0003 8 * bus clock period 1 0004 10 * bus clock period 1 0005 12 * bus clock period 1 ..... ..... 1 FFFD 131068 * bus clock period 1 FFFE 131070 * bus clock period 1 FFFF 131072 * bus clock period 1 When trimmed within specified accuracy. See electrical specifications for details. The period can be calculated as follows depending of APICLK: Period = 2*(APIR[15:0] + 1) * 0.1 ms or period = 2*(APIR[15:0] + 1) * bus clock period S12XS-Family Reference Manual, Rev. 1.03 500 PRELIMINARY Freescale Semiconductor 17.3.2.6 Reserved 06 The Reserved 06 is reserved for test purposes. 0x02F6 7 6 5 4 3 R 0 0 0 0 0 W Reset 0 0 0 0 0 = Unimplemented or Reserved Figure 17-7. Reserved 06 Voltage Regulator (S12VREGL3V3V1) 2 1 0 0 0 0 0 0 0 17.3.2.7 High Temperature Trimming Register (VREGHTTR) The VREGHTTR register allows to trim the VREG temperature sense. Fiption 0x02F7 7 6 5 4 3 2 R 0 0 0 HTOEN HTTR3 HTTR2 W Reset 0 0 0 0 01 01 1. Reset value is either 0 or preset by factory. See Section 1 (Device Overview) for details. = Unimplemented or Reserved Figure 17-8. VREGHTTR 1 HTTR1 01 0 HTTR0 01 Table 17-11. VREGHTTR field descriptions Field Description 7 HTOEN 3–0 HTTR[3:0] High Temperature Offset Enable Bit — If set the temperature sense offset is enabled 0 The temperature sense offset is disabled 1 The temperature sense offset is enabled High Temperature Trimming Bits — See Table 23-16 for trimming effects. Bit HTTR[3] HTTR[2] HTTR[1] HTTR[0] Table 17-12. Trimming Effect Trimming Effect Increases VHT twice of HTTR[2] Increases VHT twice of HTTR[1] Increases VHT twice of HTTR[0] Increases VHT (to compensate Temperature Offset) S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 501 Voltage Regulator (S12VREGL3V3V1) 17.4 Functional Description 17.4.1 General Module VREG_3V3 is a voltage regulator, as depicted in Figure 17-1. The regulator functional elements are the regulator core (REG), a low-voltage detect module (LVD), a control block (CTRL), a power-on reset module (POR), and a low-voltage reset module (LVR)and a high temperature sensor (HTD). 17.4.2 Regulator Core (REG) Respectively its regulator core has three parallel, independent regulation loops (REG1,REG2 and REG3). REG1 and REG3 differ only in the amount of current that can be delivered. The regulators are linear regulator with a bandgap reference when operated in Full Performance Mode. They act as a voltage clamp in Reduced Power Mode. All load currents flow from input VDDR to VSS or VSSPLL. The reference circuits are supplied by VDDA and VSSA. 17.4.2.1 Full Performance Mode In Full Performance Mode, the output voltage is compared with a reference voltage by an operational amplifier. The amplified input voltage difference drives the gate of an output transistor. 17.4.2.2 Reduced Power Mode In Reduced Power Mode, the gate of the output transistor is connected directly to a reference voltage to reduce power consumption. Mode switching from reduced power to full performance requires a transition time of tvup, if the voltage regulator is enabled. 17.4.3 Low-Voltage Detect (LVD) Subblock LVD is responsible for generating the low-voltage interrupt (LVI). LVD monitors the input voltage (VDDA–VSSA) and continuously updates the status flag LVDS. Interrupt flag LVIF is set whenever status flag LVDS changes its value. The LVD is available in FPM and is inactive in Reduced Power Mode or Shutdown Mode. 17.4.4 Power-On Reset (POR) This functional block monitors VDD. If VDD is below VPORD, POR is asserted; if VDD exceeds VPORD, the POR is deasserted. POR asserted forces the MCU into Reset. POR Deasserted will trigger the poweron sequence. 17.4.5 Low-Voltage Reset (LVR) Block LVR monitors the supplies VDD, VDDX and VDDF. If one (or more) drops below it’s corresponding assertion level, signal LVR asserts; if all VDD,VDDX and VDDF supplies are above their S12XS-Family Reference Manual, Rev. 1.03 502 PRELIMINARY Freescale Semiconductor Voltage Regulator (S12VREGL3V3V1) corresponding deassertion levels, signal LVR deasserts. The LVR function is available only in Full Performance Mode. 17.4.6 HTD - High Temperature Detect Subblock HTD is responsible for generating the high temperature interrupt (HTI). HTD monitors the die temperature TDIE and continuously updates the status flag HTDS. Interrupt flag HTIF is set whenever status flag HTDS changes its value. The HTD is available in FPM and is inactive in Reduced Power Mode and Shutdown Mode. The HT Trimming bits HTTR[3:0] can be set so that the temperature offset is zero, if accurate temperature measurement is desired. See Table 23-16 for the trimming effect of APITR. 17.4.7 Regulator Control (CTRL) This part contains the register block of VREG_3V3 and further digital functionality needed to control the operating modes. CTRL also represents the interface to the digital core logic. 17.4.8 Autonomous Periodical Interrupt (API) Subblock API can generate periodical interrupts independent of the clock source of the MCU. To enable the timer, the bit APIFE needs to be set. The API timer is either clocked by a trimmable internal RC oscillator or the bus clock. Timer operation will freeze when MCU clock source is selected and bus clock is turned off. See CRG specification for details. The clock source can be selected with bit APICLK. APICLK can only be written when APIFE is not set. The APIR[15:0] bits determine the interrupt period. APIR[15:0] can only be written when APIFE is cleared. As soon as APIFE is set, the timer starts running for the period selected by APIR[15:0] bits. When the configured time has elapsed, the flag APIF is set. An interrupt, indicated by flag APIF = 1, is triggered if interrupt enable bit APIE = 1. The timer is started automatically again after it has set APIF. The procedure to change APICLK or APIR[15:0] is first to clear APIFE, then write to APICLK or APIR[15:0], and afterwards set APIFE. The API Trimming bits APITR[5:0] must be set so the minimum period equals 0.2 ms if stable frequency is desired. See Table 17-8 for the trimming effect of APITR. NOTE The first period after enabling the counter by APIFE might be reduced by API start up delay tsdel. The API internal RC oscillator clock is not available if VREG_3V3 is in Shutdown Mode. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 503 Voltage Regulator (S12VREGL3V3V1) It is possible to generate with the API a waveform at an external pin by enabling the API by setting APIFE and enabling the external access with setting APIEA. By setting APIES the waveform can be selected. If APIES is set, then at the external pin a clock is visible with 2 times the selected API Period (Table 17-10). If APIES is not set, then at the external pin will be a high pulse at the end of every selected period with the size of half of the min period (Table 17-10). See device level specification for connectivity. 17.4.9 Resets This section describes how VREG_3V3 controls the reset of the MCU.The reset values of registers and signals are provided in Section 17.3, “Memory Map and Register Definition”. Possible reset sources are listed in Table 17-13. Table 17-13. Reset Sources Reset Source Power-on reset Low-voltage reset Local Enable Always active Available only in Full Performance Mode 17.4.10 Description of Reset Operation 17.4.10.1 Power-On Reset (POR) During chip power-up the digital core may not work if its supply voltage VDD is below the POR deassertion level (VPORD). Therefore, signal POR, which forces the other blocks of the device into reset, is kept high until VDD exceeds VPORD. The MCU will run the start-up sequence after POR deassertion. The power-on reset is active in all operation modes of VREG_3V3. 17.4.10.2 Low-Voltage Reset (LVR) For details on low-voltage reset, see Section 17.4.5, “Low-Voltage Reset (LVR)”. 17.4.11 Interrupts This section describes all interrupts originated by VREG_3V3. The interrupt vectors requested by VREG_3V3 are listed in Table 17-14. Vector addresses and interrupt priorities are defined at MCU level. Table 17-14. Interrupt Vectors Interrupt Source Low-voltage interrupt (LVI) High Temperature Interrupt (HTI) Autonomous periodical interrupt (API) Local Enable LVIE = 1; available only in Full Performance Mode HTIE=1; available only in Full Performance Mode APIE = 1 S12XS-Family Reference Manual, Rev. 1.03 504 PRELIMINARY Freescale Semiconductor Voltage Regulator (S12VREGL3V3V1) 17.4.11.1 Low-Voltage Interrupt (LVI) In FPM, VREG_3V3 monitors the input voltage VDDA. Whenever VDDA drops below level VLVIA, the status bit LVDS is set to 1. On the other hand, LVDS is reset to 0 when VDDA rises above level VLVID. An interrupt, indicated by flag LVIF = 1, is triggered by any change of the status bit LVDS if interrupt enable bit LVIE = 1. NOTE On entering the Reduced Power Mode, the LVIF is not cleared by the VREG_3V3. 17.4.11.2 HTI - High Temperature Interrupt In FPM VREG monitors the die temperature TDIE. Whenever TDIE exceeds level THTIA the status bit HTDS is set to 1. Vice versa, HTDS is reset to 0 when TDIE get below level THTID. An interrupt, indicated by flag HTIF=1, is triggered by any change of the status bit HTDS if interrupt enable bit HTIE=1. NOTE On entering the Reduced Power Mode the HTIF is not cleared by the VREG. 17.4.11.3 Autonomous Periodical Interrupt (API) As soon as the configured timeout period of the API has elapsed, the APIF bit is set. An interrupt, indicated by flag APIF = 1, is triggered if interrupt enable bit APIE = 1. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 505 Voltage Regulator (S12VREGL3V3V1) S12XS-Family Reference Manual, Rev. 1.03 506 PRELIMINARY Freescale Semiconductor Chapter 18 256 KByte Flash Module (S12XFTMR256K1V1) Version Num 1.2 Revision Date 15AUG07 1.3 14NOV07 1.4 03JAN08 Table 18-1. FTMR256K1 Revision History Author Description of Changes - correct MDCFAIL4-0 contents - Added block boundary address checking to ACCERR flag on command ‘Erase Verify P-Flash Section’, Section 18.4.2.3 - Added phrase alignment address checking to ACCERR flag on command ‘Erase Flash Block’, Section 18.4.2.8 - Changed terminology from ‘word program’ to “Program P-Flash’ in the BDM unsecuring description, Section 18.5.2 - Added requirement that user not write any Flash module register during execution of commands ‘Erase All Blocks’, Section 18.4.2.7, and ‘Unsecure Flash’, Section 18.4.2.10 - Added statement that security is released upon successful completion of command ‘Erase All Blocks’, Section 18.4.2.7 - Cosmetic changes S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 507 18.1 Introduction The FTMR256K1 module implements the following: • 256 Kbytes of P-Flash (Program Flash) memory • 8 Kbytes of D-Flash (Data Flash) memory The Flash memory is ideal for single-supply applications allowing for field reprogramming without requiring external high voltage sources for program or erase operations. The Flash module includes a memory controller that executes commands to modify Flash memory contents. The user interface to the memory controller consists of the indexed Flash Common Command Object (FCCOB) register which is written to with the command, global address, data, and any required command parameters. The memory controller must complete the execution of a command before the FCCOB register can be written to with a new command. CAUTION A Flash word or phrase must be in the erased state before being programmed. Cumulative programming of bits within a Flash word or phrase is not allowed. The Flash memory may be read as bytes, aligned words, or misaligned words. Read access time is one bus cycle for bytes and aligned words, and two bus cycles for misaligned words. For Flash memory, an erased bit reads 1 and a programmed bit reads 0. It is not possible to read from a Flash block while any command is executing on that specific Flash block. It is possible to read from a Flash block while a command is executing on a different Flash block. Both P-Flash and D-Flash memories are implemented with Error Correction Codes (ECC) that can resolve single bit faults and detect double bit faults. For P-Flash memory, the ECC implementation requires that programming be done on an aligned 8 byte basis (a Flash phrase). 18.1.1 Glossary Command Write Sequence — An MCU instruction sequence to execute built-in algorithms (including program and erase) on the Flash memory. D-Flash Memory — The D-Flash memory constitutes the nonvolatile memory store for data. D-Flash Sector — The D-Flash sector is the smallest portion of the D-Flash memory that can be erased. The D-Flash sector consists of four 64 byte rows for a total of 256 bytes. NVM Command Mode — An NVM mode using the CPU to setup the FCCOB register to pass parameters required for Flash command execution. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 508 256 KByte Flash Module (S12XFTMR256K1V1) Phrase — An aligned group of four 16-bit words within the P-Flash memory. Each phrase includes eight ECC bits for single bit fault correction and double bit fault detection within the phrase. P-Flash Memory — The P-Flash memory constitutes the main nonvolatile memory store for applications. P-Flash Sector — The P-Flash sector is the smallest portion of the P-Flash memory that can be erased. Each P-Flash sector contains 1024 bytes. Program IFR — Nonvolatile information register located in the P-Flash block that contains the Device ID, Version ID, and the Program Once field. The Program IFR is visible in the global memory map by setting the PGMIFRON bit in the MMCCTL1 register. 18.1.2 Features 18.1.2.1 P-Flash Features • 256 Kbytes of P-Flash memory composed of one 256 Kbyte Flash block divided into 256 sectors of 1024 bytes • Single bit fault correction and double bit fault detection within a 64-bit phrase during read operations • Automated program and erase algorithm with verify and generation of ECC parity bits • Fast sector erase and phrase program operation • Flexible protection scheme to prevent accidental program or erase of P-Flash memory 18.1.2.2 D-Flash Features • 8 Kbytes of D-Flash memory composed of one 8 Kbyte Flash block divided into 32 sectors of 256 bytes • Single bit fault correction and double bit fault detection within a word during read operations • Automated program and erase algorithm with verify and generation of ECC parity bits • Fast sector erase and word program operation • Protection scheme to prevent accidental program or erase of D-Flash memory • Ability to program up to four words in a burst sequence 18.1.2.3 Other Flash Module Features • No external high-voltage power supply required for Flash memory program and erase operations • Interrupt generation on Flash command completion and Flash error detection • Security mechanism to prevent unauthorized access to the Flash memory 18.1.3 Block Diagram The block diagram of the Flash module is shown in Figure 18-1. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 509 256 KByte Flash Module (S12XFTMR256K1V1) Command Interrupt Request Error Interrupt Request Oscillator Clock (XTAL) Flash Interface Registers Protection Security Clock Divider FCLK 16bit internal bus P-Flash 32Kx72 16Kx72 16Kx72 sector 0 sector 0 sector 1 sector 1 sector 127 sector 127 Memory Controller CPU Scratch RAM 384x16 D-Flash 4Kx22 sector 0 sector 1 sector 31 Figure 18-1. FTMR256K1 Block Diagram 18.2 External Signal Description The Flash module contains no signals that connect off-chip. 18.3 Memory Map and Registers This section describes the memory map and registers for the Flash module. Read data from unimplemented memory space in the Flash module is undefined. Write access to unimplemented or reserved memory space in the Flash module will be ignored by the Flash module. S12XS-Family Reference Manual, Rev. 1.03 510 PRELIMINARY Freescale Semiconductor 256 KByte Flash Module (S12XFTMR256K1V1) 18.3.1 Module Memory Map The S12X architecture places the P-Flash memory between global addresses 0x7C_0000 and 0x7F_FFFF as shown in Table 18-2. The P-Flash memory map is shown in Figure 18-2. Table 18-2. P-Flash Memory Addressing Global Address 0x7C_0000 – 0x7F_FFFF Size (Bytes) Description 256 K P-Flash Block 0 Contains Flash Configuration Field (see Table 18-3) The FPROT register, described in Section 18.3.2.9, can be set to protect regions in the Flash memory from accidental program or erase. Three separate memory regions, one growing upward from global address 0x7F_8000 in the Flash memory (called the lower region), one growing downward from global address 0x7F_FFFF in the Flash memory (called the higher region), and the remaining addresses in the Flash memory, can be activated for protection. The Flash memory addresses covered by these protectable regions are shown in the P-Flash memory map. The higher address region is mainly targeted to hold the boot loader code since it covers the vector space. Default protection settings as well as security information that allows the MCU to restrict access to the Flash module are stored in the Flash configuration field as described in Table 18-3. Table 18-3. Flash Configuration Field1 Global Address Size (Bytes) Description 0x7F_FF00 – 0x7F_FF07 Backdoor Comparison Key 8 Refer to Section 18.4.2.11, “Verify Backdoor Access Key Command,” and Section 18.5.1, “Unsecuring the MCU using Backdoor Key Access” 0x7F_FF08 – 0x7F_FF0B2 4 Reserved 0x7F_FF0C2 1 P-Flash Protection byte. Refer to Section 18.3.2.9, “P-Flash Protection Register (FPROT)” 0x7F_FF0D2 1 D-Flash Protection byte. Refer to Section 18.3.2.10, “D-Flash Protection Register (DFPROT)” 0x7F_FF0E2 1 Flash Nonvolatile byte Refer to Section 18.3.2.15, “Flash Option Register (FOPT)” 0x7F_FF0F2 1 Flash Security byte Refer to Section 18.3.2.2, “Flash Security Register (FSEC)” 1 Older versions may have swapped protection byte addresses 2 0x7FF08 - 0x7F_FF0F form a Flash phrase and must be programmed in a single command write sequence. Each byte in the 0x7F_FF08 - 0x7F_FF0B reserved field should be programmed to 0xFF. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 511 256 KByte Flash Module (S12XFTMR256K1V1) P-Flash START = 0x7C_0000 Flash Protected/Unprotected Region 224 Kbytes 0x7F_8000 0x7F_8400 0x7F_8800 0x7F_9000 0x7F_A000 0x7F_C000 Flash Protected/Unprotected Lower Region 1, 2, 4, 8 Kbytes Flash Protected/Unprotected Region 8 Kbytes (up to 29 Kbytes) 0x7F_E000 Flash Protected/Unprotected Higher Region 2, 4, 8, 16 Kbytes 0x7F_F000 0x7F_F800 P-Flash END = 0x7F_FFFF Flash Configuration Field 16 bytes (0x7F_FF00 - 0x7F_FF0F) Figure 18-2. P-Flash Memory Map S12XS-Family Reference Manual, Rev. 1.03 512 PRELIMINARY Freescale Semiconductor 256 KByte Flash Module (S12XFTMR256K1V1) Table 18-4. Program IFR Fields Global Address (PGMIFRON) 0x40_0000 – 0x40_0007 0x40_0008 – 0x40_00E7 0x40_00E8 – 0x40_00E9 0x40_00EA – 0x40_00FF 0x40_0100 – 0x40_013F 0x40_0140 – 0x40_01FF Size (Bytes) Field Description 8 Device ID 224 Reserved 2 Version ID 22 Reserved 64 Program Once Field Refer to Section 18.4.2.6, “Program Once Command” 192 Reserved Table 18-5. D-Flash and Memory Controller Resource Fields Global Address Size (Bytes) Description 0x10_0000 – 0x10_1FFF 0x10_2000 – 0x11_FFFF 0x12_0000 – 0x12_007F 0x12_0080 – 0x12_0FFF 0x12_1000 – 0x12_1FFF 0x12_2000 – 0x12_3CFF 0x12_3D00 – 0x12_3FFF 0x12_4000 – 0x12_E7FF 0x12_E800 – 0x12_FFFF 0x13_0000 – 0x13_FFFF 1 MMCCTL1 register bit 8,192 122,880 128 3,968 4,096 7,242 768 43,008 6,144 65,536 D-Flash Memory Reserved D-Flash Nonvolatile Information Register (DFIFRON1 = 1) Reserved Reserved Reserved Memory Controller Scratch RAM (MGRAMON1 = 1) Reserved Reserved Reserved S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 513 256 KByte Flash Module (S12XFTMR256K1V1) D-Flash START = 0x10_0000 D-Flash END = 0x10_1FFF D-Flash Memory 8 Kbytes 0x12_0000 0x12_1000 0x12_2000 0x12_4000 D-Flash Nonvolatile Information Register (DFIFRON) 128 bytes Memory Controller Scratch RAM (MGRAMON) 768 bytes 0x12_E800 0x12_FFFF Figure 18-3. D-Flash and Memory Controller Resource Memory Map S12XS-Family Reference Manual, Rev. 1.03 514 PRELIMINARY Freescale Semiconductor 256 KByte Flash Module (S12XFTMR256K1V1) 18.3.2 Register Descriptions The Flash module contains a set of 20 control and status registers located between Flash module base + 0x0000 and 0x0013. A summary of the Flash module registers is given in Figure 18-4 with detailed descriptions in the following subsections. Address & Name 0x0000 FCLKDIV 7 R FDIVLD W 6 FDIV6 5 FDIV5 4 FDIV4 3 FDIV3 2 FDIV2 1 FDIV1 0 FDIV0 0x0001 FSEC R KEYEN1 W KEYEN0 RNV5 RNV4 RNV3 RNV2 SEC1 SEC0 0x0002 R 0 FCCOBIX W 0 0 0 0 CCOBIX2 CCOBIX1 CCOBIX0 0x0003 R 0 FECCRIX W 0 0 0 0 ECCRIX2 ECCRIX1 ECCRIX0 0x0004 FCNFG R CCIE W 0 0 0 IGNSF 0 FDFD FSFD 0x0005 R 0 FERCNFG W DFDIE SFDIE 0x0006 FSTAT R CCIF W 0 MGBUSY RSVD MGSTAT1 MGSTAT0 ACCERR FPVIOL 0x0007 R 0 FERSTAT W 0 0 0 0 0 DFDIF SFDIF 0x0008 FPROT R FPOPEN W RNV6 FPHDIS FPHS1 FPHS0 FPLDIS FPLS1 FPLS0 0x0009 DFPROT R DPOPEN W 0 0 DPS4 DPS3 DPS2 DPS1 DPS0 0x000A FCCOBHI R CCOB15 W CCOB14 CCOB13 CCOB12 CCOB11 CCOB10 CCOB9 CCOB8 0x000B FCCOBLO R W CCOB7 CCOB6 CCOB5 CCOB4 CCOB3 CCOB2 CCOB1 CCOB0 Figure 18-4. FTMR256K1 Register Summary S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 515 256 KByte Flash Module (S12XFTMR256K1V1) Address & Name 7 6 5 4 3 2 0x000C R 0 0 0 0 0 0 FRSV0 W 0x000D R 0 0 0 0 0 0 FRSV1 W 0x000E FECCRHI R ECCR15 W ECCR14 ECCR13 ECCR12 ECCR11 ECCR10 0x000F R ECCR7 FECCRLO W ECCR6 ECCR5 ECCR4 ECCR3 ECCR2 0x0010 R NV7 NV6 NV5 NV4 NV3 NV2 FOPT W 0x0011 R 0 0 0 0 0 0 FRSV2 W 0x0012 R 0 0 0 0 0 0 FRSV3 W 0x0013 R 0 0 0 0 0 0 FRSV4 W = Unimplemented or Reserved 1 0 0 ECCR9 ECCR1 NV1 0 0 0 0 0 0 ECCR8 ECCR0 NV0 0 0 0 Figure 18-4. FTMR256K1 Register Summary (continued) 18.3.2.1 Flash Clock Divider Register (FCLKDIV) The FCLKDIV register is used to control timed events in program and erase algorithms. Offset Module Base + 0x0000 7 6 5 4 3 2 1 0 R FDIVLD W FDIV[6:0] Reset 0 0 0 0 0 0 0 0 = Unimplemented or Reserved Figure 18-5. Flash Clock Divider Register (FCLKDIV) All bits in the FCLKDIV register are readable, bits 6–0 are write once and bit 7 is not writable. S12XS-Family Reference Manual, Rev. 1.03 516 PRELIMINARY Freescale Semiconductor 256 KByte Flash Module (S12XFTMR256K1V1) Table 18-6. FCLKDIV Field Descriptions Field Description 7 FDIVLD 6–0 FDIV[6:0] Clock Divider Loaded 0 FCLKDIV register has not been written 1 FCLKDIV register has been written since the last reset Clock Divider Bits — FDIV[6:0] must be set to effectively divide OSCCLK down to generate an internal Flash clock, FCLK, with a target frequency of 1 MHz for use by the Flash module to control timed events during program and erase algorithms. Table 18-7 shows recommended values for FDIV[6:0] based on OSCCLK frequency. Please refer to Section 18.4.1, “Flash Command Operations,” for more information. CAUTION The FCLKDIV register should never be written while a Flash command is executing (CCIF=0). S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 517 256 KByte Flash Module (S12XFTMR256K1V1) Table 18-7. FDIV vs OSCCLK Frequency OSCCLK Frequency (MHz) MIN1 MAX2 FDIV[6:0] OSCCLK Frequency (MHz) MIN1 MAX2 1.60 2.10 0x01 33.60 34.65 2.40 3.15 0x02 3.20 4.20 0x03 4.20 5.25 0x04 5.25 6.30 0x05 6.30 7.35 0x06 34.65 35.70 36.75 37.80 38.85 35.70 36.75 37.80 38.85 39.90 7.35 8.40 9.45 10.50 8.40 9.45 10.50 11.55 0x07 0x08 0x09 0x0A 39.90 40.95 42.00 43.05 40.95 42.00 43.05 44.10 11.55 12.60 13.65 14.70 15.75 12.60 13.65 14.70 15.75 16.80 0x0B 0x0C 0x0D 0x0E 0x0F 44.10 45.15 46.20 47.25 48.30 45.15 46.20 47.25 48.30 49.35 16.80 17.85 18.90 19.95 17.85 18.90 19.95 21.00 0x10 0x11 0x12 0x13 49.35 50.40 21.00 22.05 23.10 24.15 25.20 22.05 23.10 24.15 25.20 26.25 0x14 0x15 0x16 0x17 0x18 26.25 27.30 28.35 29.40 27.30 28.35 29.40 30.45 0x19 0x1A 0x1B 0x1C 30.45 31.50 0x1D 31.50 32.55 0x1E 32.55 33.60 0x1F 1 FDIV shown generates an FCLK frequency of >0.8 MHz 2 FDIV shown generates an FCLK frequency of 1.05 MHz FDIV[6:0] 0x20 0x21 0x22 0x23 0x24 0x25 0x26 0x27 0x28 0x29 0x2A 0x2B 0x2C 0x2D 0x2E 0x2F S12XS-Family Reference Manual, Rev. 1.03 518 PRELIMINARY Freescale Semiconductor 256 KByte Flash Module (S12XFTMR256K1V1) 18.3.2.2 Flash Security Register (FSEC) The FSEC register holds all bits associated with the security of the MCU and Flash module. Offset Module Base + 0x0001 R W Reset 7 6 5 4 3 2 KEYEN[1:0] RNV[5:2] F F F F F F = Unimplemented or Reserved Figure 18-6. Flash Security Register (FSEC) 1 0 SEC[1:0] F F All bits in the FSEC register are readable but not writable. During the reset sequence, the FSEC register is loaded with the contents of the Flash security byte in the Flash configuration field at global address 0x7F_FF0F located in P-Flash memory (see Table 18-3) as indicated by reset condition F in Figure 18-6. If a double bit fault is detected while reading the P-Flash phrase containing the Flash security byte during the reset sequence, all bits in the FSEC register will be set to leave the Flash module in a secured state with backdoor key access disabled. Table 18-8. FSEC Field Descriptions Field Description 7–6 Backdoor Key Security Enable Bits — The KEYEN[1:0] bits define the enabling of backdoor key access to the KEYEN[1:0] Flash module as shown in Table 18-9. 5–2 Reserved Nonvolatile Bits — The RNV bits should remain in the erased state for future enhancements. RNV[5:2} 1–0 Flash Security Bits — The SEC[1:0] bits define the security state of the MCU as shown in Table 18-10. If the SEC[1:0] Flash module is unsecured using backdoor key access, the SEC bits are forced to 10. Table 18-9. Flash KEYEN States KEYEN[1:0] Status of Backdoor Key Access 00 DISABLED 01 DISABLED1 10 ENABLED 11 DISABLED 1 Preferred KEYEN state to disable backdoor key access. Table 18-10. Flash Security States SEC[1:0] 00 01 10 11 Status of Security SECURED SECURED1 UNSECURED SECURED S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 519 256 KByte Flash Module (S12XFTMR256K1V1) 1 Preferred SEC state to set MCU to secured state. The security function in the Flash module is described in Section 18.5. 18.3.2.3 Flash CCOB Index Register (FCCOBIX) The FCCOBIX register is used to index the FCCOB register for Flash memory operations. Offset Module Base + 0x0002 7 6 5 4 3 2 1 0 R 0 0 0 0 0 W CCOBIX[2:0] Reset 0 0 0 0 0 0 0 0 = Unimplemented or Reserved Figure 18-7. FCCOB Index Register (FCCOBIX) CCOBIX bits are readable and writable while remaining bits read 0 and are not writable. Table 18-11. FCCOBIX Field Descriptions Field Description 2–0 Common Command Register Index— The CCOBIX bits are used to select which word of the FCCOB register CCOBIX[1:0] array is being read or written to. See 18.3.2.11 Flash Common Command Object Register (FCCOB),” for more details. 18.3.2.4 Flash ECCR Index Register (FECCRIX) The FECCRIX register is used to index the FECCR register for ECC fault reporting. Offset Module Base + 0x0003 7 6 5 4 3 2 1 0 R 0 0 0 0 0 W ECCRIX[2:0] Reset 0 0 0 0 0 0 0 0 = Unimplemented or Reserved Figure 18-8. FECCR Index Register (FECCRIX) ECCRIX bits are readable and writable while remaining bits read 0 and are not writable. Table 18-12. FECCRIX Field Descriptions Field Description 2-0 ECC Error Register Index— The ECCRIX bits are used to select which word of the FECCR register array is ECCRIX[2:0] being read. See 18.3.2.14 Flash ECC Error Results Register (FECCR),” for more details. S12XS-Family Reference Manual, Rev. 1.03 520 PRELIMINARY Freescale Semiconductor 256 KByte Flash Module (S12XFTMR256K1V1) 18.3.2.5 Flash Configuration Register (FCNFG) The FCNFG register enables the Flash command complete interrupt and forces ECC faults on Flash array read access from the CPU or XGATE. Offset Module Base + 0x0004 R W Reset 7 CCIE 0 6 5 4 3 2 0 0 0 0 IGNSF 0 0 0 0 0 = Unimplemented or Reserved Figure 18-9. Flash Configuration Register (FCNFG) 1 FDFD 0 0 FSFD 0 CCIE, IGNSF, FDFD, and FSFD bits are readable and writable while remaining bits read 0 and are not writable. Table 18-13. FCNFG Field Descriptions Field 7 CCIE 4 IGNSF 1 FDFD 0 FSFD Description Command Complete Interrupt Enable — The CCIE bit controls interrupt generation when a Flash command has completed. 0 Command complete interrupt disabled 1 An interrupt will be requested whenever the CCIF flag in the FSTAT register is set (see Section 18.3.2.7) Ignore Single Bit Fault — The IGNSF controls single bit fault reporting in the FERSTAT register (see Section 18.3.2.8). 0 All single bit faults detected during array reads are reported 1 Single bit faults detected during array reads are not reported and the single bit fault interrupt will not be generated Force Double Bit Fault Detect — The FDFD bit allows the user to simulate a double bit fault during Flash array read operations and check the associated interrupt routine. The FDFD bit is cleared by writing a 0 to FDFD. The FECCR registers will not be updated during the Flash array read operation with FDFD set unless an actual double bit fault is detected. 0 Flash array read operations will set the DFDIF flag in the FERSTAT register only if a double bit fault is detected 1 Any Flash array read operation will force the DFDIF flag in the FERSTAT register to be set (see Section 18.3.2.7) and an interrupt will be generated as long as the DFDIE interrupt enable in the FERCNFG register is set (see Section 18.3.2.6) Force Single Bit Fault Detect — The FSFD bit allows the user to simulate a single bit fault during Flash array read operations and check the associated interrupt routine. The FSFD bit is cleared by writing a 0 to FSFD. The FECCR registers will not be updated during the Flash array read operation with FSFD set unless an actual single bit fault is detected. 0 Flash array read operations will set the SFDIF flag in the FERSTAT register only if a single bit fault is detected 1 Flash array read operation will force the SFDIF flag in the FERSTAT register to be set (see Section 18.3.2.7) and an interrupt will be generated as long as the SFDIE interrupt enable in the FERCNFG register is set (see Section 18.3.2.6) 18.3.2.6 Flash Error Configuration Register (FERCNFG) The FERCNFG register enables the Flash error interrupts for the FERSTAT flags. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 521 256 KByte Flash Module (S12XFTMR256K1V1) Offset Module Base + 0x0005 7 6 5 4 3 2 1 R 0 W DFDIE Reset 0 0 0 0 0 0 0 = Unimplemented or Reserved Figure 18-10. Flash Error Configuration Register (FERCNFG) 0 SFDIE 0 All assigned bits in the FERCNFG register are readable and writable. Table 18-14. FERCNFG Field Descriptions Field 1 DFDIE 0 SFDIE Description Double Bit Fault Detect Interrupt Enable — The DFDIE bit controls interrupt generation when a double bit fault is detected during a Flash block read operation. 0 DFDIF interrupt disabled 1 An interrupt will be requested whenever the DFDIF flag is set (see Section 18.3.2.8) Single Bit Fault Detect Interrupt Enable — The SFDIE bit controls interrupt generation when a single bit fault is detected during a Flash block read operation. 0 SFDIF interrupt disabled whenever the SFDIF flag is set (see Section 18.3.2.8) 1 An interrupt will be requested whenever the SFDIF flag is set (see Section 18.3.2.8) 18.3.2.7 Flash Status Register (FSTAT) The FSTAT register reports the operational status of the Flash module. Offset Module Base + 0x0006 R W Reset 7 CCIF 1 6 5 4 3 2 0 MGBUSY RSVD ACCERR FPVIOL 0 0 0 0 0 1 0 MGSTAT[1:0] 01 01 = Unimplemented or Reserved Figure 18-11. Flash Status Register (FSTAT) 1 Reset value can deviate from the value shown if a double bit fault is detected during the reset sequence (see Section 18.6). CCIF, ACCERR, and FPVIOL bits are readable and writable, MGBUSY and MGSTAT bits are readable but not writable, while remaining bits read 0 and are not writable. S12XS-Family Reference Manual, Rev. 1.03 522 PRELIMINARY Freescale Semiconductor 256 KByte Flash Module (S12XFTMR256K1V1) Table 18-15. FSTAT Field Descriptions Field Description 7 CCIF Command Complete Interrupt Flag — The CCIF flag indicates that a Flash command has completed. The CCIF flag is cleared by writing a 1 to CCIF to launch a command and CCIF will stay low until command completion or command violation. 0 Flash command in progress 1 Flash command has completed 5 ACCERR Flash Access Error Flag — The ACCERR bit indicates an illegal access has occurred to the Flash memory caused by either a violation of the command write sequence (see Section 18.4.1.2) or issuing an illegal Flash command. While ACCERR is set, the CCIF flag cannot be cleared to launch a command. The ACCERR bit is cleared by writing a 1 to ACCERR. Writing a 0 to the ACCERR bit has no effect on ACCERR. 0 No access error detected 1 Access error detected 4 FPVIOL Flash Protection Violation Flag —The FPVIOL bit indicates an attempt was made to program or erase an address in a protected area of P-Flash or D-Flash memory during a command write sequence. The FPVIOL bit is cleared by writing a 1 to FPVIOL. Writing a 0 to the FPVIOL bit has no effect on FPVIOL. While FPVIOL is set, it is not possible to launch a command or start a command write sequence. 0 No protection violation detected 1 Protection violation detected 3 MGBUSY Memory Controller Busy Flag — The MGBUSY flag reflects the active state of the Memory Controller. 0 Memory Controller is idle 1 Memory Controller is busy executing a Flash command (CCIF = 0) 2 RSVD Reserved Bit — This bit is reserved and always reads 0. 1–0 Memory Controller Command Completion Status Flag — One or more MGSTAT flag bits are set if an error MGSTAT[1:0] is detected during execution of a Flash command or during the Flash reset sequence. See Section 18.4.2, “Flash Command Description,” and Section 18.6, “Initialization” for details. 18.3.2.8 Flash Error Status Register (FERSTAT) The FERSTAT register reflects the error status of internal Flash operations. Offset Module Base + 0x0007 7 6 5 4 3 2 1 R 0 0 0 0 0 0 DFDIF W Reset 0 0 0 0 0 0 0 = Unimplemented or Reserved Figure 18-12. Flash Error Status Register (FERSTAT) All flags in the FERSTAT register are readable and only writable to clear the flag. 0 SFDIF 0 S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 523 256 KByte Flash Module (S12XFTMR256K1V1) Field 1 DFDIF 0 SFDIF Table 18-16. FERSTAT Field Descriptions Description Double Bit Fault Detect Interrupt Flag — The setting of the DFDIF flag indicates that a double bit fault was detected in the stored parity and data bits during a Flash array read operation or that a Flash array read operation was attempted on a Flash block that was under a Flash command operation. The DFDIF flag is cleared by writing a 1 to DFDIF. Writing a 0 to DFDIF has no effect on DFDIF. 0 No double bit fault detected 1 Double bit fault detected or an invalid Flash array read operation attempted Single Bit Fault Detect Interrupt Flag — With the IGNSF bit in the FCNFG register clear, the SFDIF flag indicates that a single bit fault was detected in the stored parity and data bits during a Flash array read operation or that a Flash array read operation was attempted on a Flash block that was under a Flash command operation. The SFDIF flag is cleared by writing a 1 to SFDIF. Writing a 0 to SFDIF has no effect on SFDIF. 0 No single bit fault detected 1 Single bit fault detected and corrected or an invalid Flash array read operation attempted 18.3.2.9 P-Flash Protection Register (FPROT) The FPROT register defines which P-Flash sectors are protected against program and erase operations. Offset Module Base + 0x0008 7 R FPOPEN W 6 RNV6 5 FPHDIS 4 3 FPHS[1:0] 2 FPLDIS Reset F F F F F F = Unimplemented or Reserved Figure 18-13. Flash Protection Register (FPROT) 1 0 FPLS[1:0] F F The (unreserved) bits of the FPROT register are writable with the restriction that the size of the protected region can only be increased (see Section 18.3.2.9.1, “P-Flash Protection Restrictions,” and Table 18-21). During the reset sequence, the FPROT register is loaded with the contents of the P-Flash protection byte in the Flash configuration field at global address 0x7F_FF0C located in P-Flash memory (see Table 18-3) as indicated by reset condition ‘F’ in Figure 18-13. To change the P-Flash protection that will be loaded during the reset sequence, the upper sector of the P-Flash memory must be unprotected, then the P-Flash protection byte must be reprogrammed. If a double bit fault is detected while reading the P-Flash phrase containing the P-Flash protection byte during the reset sequence, the FPOPEN bit will be cleared and remaining bits in the FPROT register will be set to leave the P-Flash memory fully protected. Trying to alter data in any protected area in the P-Flash memory will result in a protection violation error and the FPVIOL bit will be set in the FSTAT register. The block erase of a P-Flash block is not possible if any of the P-Flash sectors contained in the same P-Flash block are protected. S12XS-Family Reference Manual, Rev. 1.03 524 PRELIMINARY Freescale Semiconductor 256 KByte Flash Module (S12XFTMR256K1V1) Table 18-17. FPROT Field Descriptions Field Description 7 FPOPEN Flash Protection Operation Enable — The FPOPEN bit determines the protection function for program or erase operations as shown in Table 18-18 for the P-Flash block. 0 When FPOPEN is clear, the FPHDIS and FPLDIS bits define unprotected address ranges as specified by the corresponding FPHS and FPLS bits 1 When FPOPEN is set, the FPHDIS and FPLDIS bits enable protection for the address range specified by the corresponding FPHS and FPLS bits 6 Reserved Nonvolatile Bit — The RNV bit should remain in the erased state for future enhancements. RNV[6] 5 FPHDIS Flash Protection Higher Address Range Disable — The FPHDIS bit determines whether there is a protected/unprotected area in a specific region of the P-Flash memory ending with global address 0x7F_FFFF. 0 Protection/Unprotection enabled 1 Protection/Unprotection disabled 4–3 Flash Protection Higher Address Size — The FPHS bits determine the size of the protected/unprotected area FPHS[1:0] in P-Flash memory as shown inTable 18-19. The FPHS bits can only be written to while the FPHDIS bit is set. 2 FPLDIS Flash Protection Lower Address Range Disable — The FPLDIS bit determines whether there is a protected/unprotected area in a specific region of the P-Flash memory beginning with global address 0x7F_8000. 0 Protection/Unprotection enabled 1 Protection/Unprotection disabled 1–0 Flash Protection Lower Address Size — The FPLS bits determine the size of the protected/unprotected area FPLS[1:0] in P-Flash memory as shown in Table 18-20. The FPLS bits can only be written to while the FPLDIS bit is set. Table 18-18. P-Flash Protection Function FPOPEN FPHDIS FPLDIS Function1 1 1 1 No P-Flash Protection 1 1 0 Protected Low Range 1 0 1 Protected High Range 1 0 0 Protected High and Low Ranges 0 1 1 Full P-Flash Memory Protected 0 1 0 Unprotected Low Range 0 0 1 Unprotected High Range 0 0 0 Unprotected High and Low Ranges 1 For range sizes, refer to Table 18-19 and Table 18-20. Table 18-19. P-Flash Protection Higher Address Range FPHS[1:0] 00 01 10 11 Global Address Range 0x7F_F800–0x7F_FFFF 0x7F_F000–0x7F_FFFF 0x7F_E000–0x7F_FFFF 0x7F_C000–0x7F_FFFF Protected Size 2 Kbytes 4 Kbytes 8 Kbytes 16 Kbytes S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 525 256 KByte Flash Module (S12XFTMR256K1V1) Table 18-20. P-Flash Protection Lower Address Range FPLS[1:0] 00 01 10 11 Global Address Range 0x7F_8000–0x7F_83FF 0x7F_8000–0x7F_87FF 0x7F_8000–0x7F_8FFF 0x7F_8000–0x7F_9FFF Protected Size 1 Kbyte 2 Kbytes 4 Kbytes 8 Kbytes All possible P-Flash protection scenarios are shown in Figure 18-14. Although the protection scheme is loaded from the Flash memory at global address 0x7F_FF0C during the reset sequence, it can be changed by the user. The P-Flash protection scheme can be used by applications requiring reprogramming in single chip mode while providing as much protection as possible if reprogramming is not required. S12XS-Family Reference Manual, Rev. 1.03 526 PRELIMINARY Freescale Semiconductor 256 KByte Flash Module (S12XFTMR256K1V1) FPHDIS = 1 FPLDIS = 1 Scenario 7 FLASH START FPHDIS = 1 FPLDIS = 0 6 FPHDIS = 0 FPLDIS = 1 5 FPHDIS = 0 FPLDIS = 0 4 FPHS[1:0] FPLS[1:0] FPOPEN = 1 0x7F_8000 0x7F_FFFF Scenario 3 2 1 0 FLASH START FPHS[1:0] FPLS[1:0] FPOPEN = 0 0x7F_8000 0x7F_FFFF Unprotected region Protected region not defined by FPLS, FPHS Protected region with size defined by FPLS Protected region with size defined by FPHS Figure 18-14. P-Flash Protection Scenarios S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 527 256 KByte Flash Module (S12XFTMR256K1V1) 18.3.2.9.1 P-Flash Protection Restrictions The general guideline is that P-Flash protection can only be added and not removed. Table 18-21 specifies all valid transitions between P-Flash protection scenarios. Any attempt to write an invalid scenario to the FPROT register will be ignored. The contents of the FPROT register reflect the active protection scenario. See the FPHS and FPLS bit descriptions for additional restrictions. Table 18-21. P-Flash Protection Scenario Transitions From To Protection Scenario1 Protection Scenario 0 1 2 3 4 5 6 7 0 X X X X 1 X X 2 X X 3 X 4 X X 5 X X X X 6 X X X X 7 X X X X X X X X 1 Allowed transitions marked with X, see Figure 18-14 for a definition of the scenarios. 18.3.2.10 D-Flash Protection Register (DFPROT) The DFPROT register defines which D-Flash sectors are protected against program and erase operations. Offset Module Base + 0x0009 7 6 5 4 3 2 1 0 R 0 0 DPOPEN W DPS[4:0] Reset F 0 0 F F F F F = Unimplemented or Reserved Figure 18-15. D-Flash Protection Register (DFPROT) The (unreserved) bits of the DFPROT register are writable with the restriction that protection can be added but not removed. Writes must increase the DPS value and the DPOEN bit can only be written from 1 (protection disabled) to 0 (protection enabled). If the DPOPEN bit is set, the state of the DPS bits is irrelevant. During the reset sequence, the DFPROT register is loaded with the contents of the D-Flash protection byte in the Flash configuration field at global address 0x7F_FF0D located in P-Flash memory (see Table 18-3) as indicated by reset condition F in Figure 18-15. To change the D-Flash protection that will be loaded during the reset sequence, the P-Flash sector containing the D-Flash protection byte must be unprotected, then the D-Flash protection byte must be programmed. If a double bit fault is detected while reading the S12XS-Family Reference Manual, Rev. 1.03 528 PRELIMINARY Freescale Semiconductor 256 KByte Flash Module (S12XFTMR256K1V1) P-Flash phrase containing the D-Flash protection byte during the reset sequence, the DPOPEN bit will be cleared and DPS bits will be set to leave the D-Flash memory fully protected. Trying to alter data in any protected area in the D-Flash memory will result in a protection violation error and the FPVIOL bit will be set in the FSTAT register. Block erase of the D-Flash memory is not possible if any of the D-Flash sectors are protected. Table 18-22. DFPROT Field Descriptions Field Description 7 DPOPEN 4–0 DPS[4:0] D-Flash Protection Control 0 Enables D-Flash memory protection from program and erase with protected address range defined by DPS bits 1 Disables D-Flash memory protection from program and erase D-Flash Protection Size — The DPS[4:0] bits determine the size of the protected area in the D-Flash memory as shown in Table 18-23. Table 18-23. D-Flash Protection Address Range DPS[4:0] 0_0000 0_0001 0_0010 0_0011 0_0100 0_0101 0_0110 0_0111 0_1000 0_1001 0_1010 0_1011 0_1100 0_1101 0_1110 0_1111 1_0000 1_0001 1_0010 1_0011 1_0100 1_0101 Global Address Range 0x10_0000 – 0x10_00FF 0x10_0000 – 0x10_01FF 0x10_0000 – 0x10_02FF 0x10_0000 – 0x10_03FF 0x10_0000 – 0x10_04FF 0x10_0000 – 0x10_05FF 0x10_0000 – 0x10_06FF 0x10_0000 – 0x10_07FF 0x10_0000 – 0x10_08FF 0x10_0000 – 0x10_09FF 0x10_0000 – 0x10_0AFF 0x10_0000 – 0x10_0BFF 0x10_0000 – 0x10_0CFF 0x10_0000 – 0x10_0DFF 0x10_0000 – 0x10_0EFF 0x10_0000 – 0x10_0FFF 0x10_0000 – 0x10_10FF 0x10_0000 – 0x10_11FF 0x10_0000 – 0x10_12FF 0x10_0000 – 0x10_13FF 0x10_0000 – 0x10_14FF 0x10_0000 – 0x10_15FF Protected Size 256 bytes 512 bytes 768 bytes 1024 bytes 1280 bytes 1536 bytes 1792 bytes 2048 bytes 2304 bytes 2560 bytes 2816 bytes 3072 bytes 3328 bytes 3584 bytes 3840 bytes 4096 bytes 4352 bytes 4608 bytes 4864 bytes 5120 bytes 5376 bytes 5632 bytes S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 529 256 KByte Flash Module (S12XFTMR256K1V1) Table 18-23. D-Flash Protection Address Range DPS[4:0] 1_0110 1_0111 1_1000 1_1001 1_1010 1_1011 1_1100 1_1101 1_1110 1_1111 Global Address Range 0x10_0000 – 0x10_16FF 0x10_0000 – 0x10_17FF 0x10_0000 – 0x10_18FF 0x10_0000 – 0x10_19FF 0x10_0000 – 0x10_1AFF 0x10_0000 – 0x10_1BFF 0x10_0000 – 0x10_1CFF 0x10_0000 – 0x10_1DFF 0x10_0000 – 0x10_1EFF 0x10_0000 – 0x10_1FFF Protected Size 5888 bytes 6144 bytes 6400 bytes 6656 bytes 6912 bytes 7168 bytes 7424 bytes 7680 bytes 7936 bytes 8192 bytes 18.3.2.11 Flash Common Command Object Register (FCCOB) The FCCOB is an array of six words addressed via the CCOBIX index found in the FCCOBIX register. Byte wide reads and writes are allowed to the FCCOB register. Offset Module Base + 0x000A 7 6 5 4 3 2 1 0 R CCOB[15:8] W Reset 0 0 0 0 0 0 0 0 Figure 18-16. Flash Common Command Object High Register (FCCOBHI) Offset Module Base + 0x000B 7 6 5 4 3 2 1 0 R CCOB[7:0] W Reset 0 0 0 0 0 0 0 0 Figure 18-17. Flash Common Command Object Low Register (FCCOBLO) 18.3.2.11.1 FCCOB - NVM Command Mode NVM command mode uses the indexed FCCOB register to provide a command code and its relevant parameters to the Memory Controller. The user first sets up all required FCCOB fields and then initiates the command’s execution by writing a 1 to the CCIF bit in the FSTAT register (a 1 written by the user clears the CCIF command completion flag to 0). When the user clears the CCIF bit in the FSTAT register all FCCOB parameter fields are locked and cannot be changed by the user until the command completes S12XS-Family Reference Manual, Rev. 1.03 530 PRELIMINARY Freescale Semiconductor 256 KByte Flash Module (S12XFTMR256K1V1) (as evidenced by the Memory Controller returning CCIF to 1). Some commands return information to the FCCOB register array. The generic format for the FCCOB parameter fields in NVM command mode is shown in Table 18-24. The return values are available for reading after the CCIF flag in the FSTAT register has been returned to 1 by the Memory Controller. Writes to the unimplemented parameter fields (CCOBIX = 110 and CCOBIX = 111) are ignored with reads from these fields returning 0x0000. Table 18-24 shows the generic Flash command format. The high byte of the first word in the CCOB array contains the command code, followed by the parameters for this specific Flash command. For details on the FCCOB settings required by each command, see the Flash command descriptions in Section 18.4.2. Table 18-24. FCCOB - NVM Command Mode (Typical Usage) CCOBIX[2:0] 000 001 010 011 100 101 Byte HI LO HI LO HI LO HI LO HI LO HI LO FCCOB Parameter Fields (NVM Command Mode) FCMD[7:0] defining Flash command 0, Global address [22:16] Global address [15:8] Global address [7:0] Data 0 [15:8] Data 0 [7:0] Data 1 [15:8] Data 1 [7:0] Data 2 [15:8] Data 2 [7:0] Data 3 [15:8] Data 3 [7:0] 18.3.2.12 Flash Reserved0 Register (FRSV0) This Flash register is reserved for factory testing. Offset Module Base + 0x000C 7 6 5 4 3 2 1 0 R 0 0 0 0 0 0 0 0 W Reset 0 0 0 0 0 0 0 0 = Unimplemented or Reserved Figure 18-18. Flash Reserved0 Register (FRSV0) All bits in the FRSV0 register read 0 and are not writable. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 531 256 KByte Flash Module (S12XFTMR256K1V1) 18.3.2.13 Flash Reserved1 Register (FRSV1) This Flash register is reserved for factory testing. Offset Module Base + 0x000D 7 6 5 4 3 2 1 0 R 0 0 0 0 0 0 0 0 W Reset 0 0 0 0 0 0 0 0 = Unimplemented or Reserved Figure 18-19. Flash Reserved1 Register (FRSV1) All bits in the FRSV1 register read 0 and are not writable. 18.3.2.14 Flash ECC Error Results Register (FECCR) The FECCR registers contain the result of a detected ECC fault for both single bit and double bit faults. The FECCR register provides access to several ECC related fields as defined by the ECCRIX index bits in the FECCRIX register (see Section 18.3.2.4). Once ECC fault information has been stored, no other fault information will be recorded until the specific ECC fault flag has been cleared. In the event of simultaneous ECC faults the priority for fault recording is double bit fault over single bit fault. Offset Module Base + 0x000E 7 6 5 4 3 2 1 0 R ECCR[15:8] W Reset 0 0 0 0 0 0 0 0 = Unimplemented or Reserved Figure 18-20. Flash ECC Error Results High Register (FECCRHI) Offset Module Base + 0x000F 7 6 5 4 3 2 1 0 R ECCR[7:0] W Reset 0 0 0 0 0 0 0 0 = Unimplemented or Reserved Figure 18-21. Flash ECC Error Results Low Register (FECCRLO) All FECCR bits are readable but not writable. S12XS-Family Reference Manual, Rev. 1.03 532 PRELIMINARY Freescale Semiconductor 256 KByte Flash Module (S12XFTMR256K1V1) ECCRIX[2:0] 000 001 010 011 100 101 110 111 Table 18-25. FECCR Index Settings FECCR Register Content Bits [15:8] Bit[7] Bits[6:0] Parity bits read from Flash block 0 Global address [22:16] Global address [15:0] Data 0 [15:0] Data 1 [15:0] (P-Flash only) Data 2 [15:0] (P-Flash only) Data 3 [15:0] (P-Flash only) Not used, returns 0x0000 when read Not used, returns 0x0000 when read Table 18-26. FECCR Index=000 Bit Descriptions Field Description 15:8 PAR[7:0] ECC Parity Bits — Contains the 8 parity bits from the 72 bit wide P-Flash data word or the 6 parity bits, allocated to PAR[5:0], from the 22 bit wide D-Flash word with PAR[7:6]=00. 6–0 Global Address — The GADDR[22:16] field contains the upper seven bits of the global address having GADDR[22:16] caused the error. The P-Flash word addressed by ECCRIX = 001 contains the lower 16 bits of the global address. The following four words addressed by ECCRIX = 010 to 101 contain the 64-bit wide data phrase. The four data words and the parity byte are the uncorrected data read from the P-Flash block. The D-Flash word addressed by ECCRIX = 001 contains the lower 16 bits of the global address. The uncorrected 16-bit data word is addressed by ECCRIX = 010. 18.3.2.15 Flash Option Register (FOPT) The FOPT register is the Flash option register. Offset Module Base + 0x0010 7 6 5 4 3 2 1 0 R NV[7:0] W Reset F F F F F F F F = Unimplemented or Reserved Figure 18-22. Flash Option Register (FOPT) All bits in the FOPT register are readable but are not writable. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 533 256 KByte Flash Module (S12XFTMR256K1V1) During the reset sequence, the FOPT register is loaded from the Flash nonvolatile byte in the Flash configuration field at global address 0x7F_FF0E located in P-Flash memory (see Table 18-3) as indicated by reset condition F in Figure 18-22. If a double bit fault is detected while reading the P-Flash phrase containing the Flash nonvolatile byte during the reset sequence, all bits in the FOPT register will be set. Table 18-27. FOPT Field Descriptions Field 7–0 NV[7:0] Description Nonvolatile Bits — The NV[7:0] bits are available as nonvolatile bits. Refer to the device user guide for proper use of the NV bits. 18.3.2.16 Flash Reserved2 Register (FRSV2) This Flash register is reserved for factory testing. Offset Module Base + 0x0011 7 6 5 4 3 2 1 0 R 0 0 0 0 0 0 0 0 W Reset 0 0 0 0 0 0 0 0 = Unimplemented or Reserved Figure 18-23. Flash Reserved2 Register (FRSV2) All bits in the FRSV2 register read 0 and are not writable. 18.3.2.17 Flash Reserved3 Register (FRSV3) This Flash register is reserved for factory testing. Offset Module Base + 0x0012 7 6 5 4 3 2 1 0 R 0 0 0 0 0 0 0 0 W Reset 0 0 0 0 0 0 0 0 = Unimplemented or Reserved Figure 18-24. Flash Reserved3 Register (FRSV3) All bits in the FRSV3 register read 0 and are not writable. 18.3.2.18 Flash Reserved4 Register (FRSV4) This Flash register is reserved for factory testing. S12XS-Family Reference Manual, Rev. 1.03 534 PRELIMINARY Freescale Semiconductor 256 KByte Flash Module (S12XFTMR256K1V1) Offset Module Base + 0x0013 7 6 5 4 3 2 1 0 R 0 0 0 0 0 0 0 0 W Reset 0 0 0 0 0 0 0 0 = Unimplemented or Reserved Figure 18-25. Flash Reserved4 Register (FRSV4) All bits in the FRSV4 register read 0 and are not writable. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 535 256 KByte Flash Module (S12XFTMR256K1V1) 18.4 Functional Description 18.4.1 Flash Command Operations Flash command operations are used to modify Flash memory contents. The next sections describe: • How to write the FCLKDIV register that is used to generate a time base (FCLK) derived from the OSCCLK for Flash program and erase command operations • The command write sequence used to set Flash command parameters and launch execution • Valid Flash commands available for execution 18.4.1.1 Writing the FCLKDIV Register Prior to issuing any Flash program or erase command after a reset, the user is required to write the FCLKDIV register to divide OSCCLK down to a target FCLK of 1 MHz. Table 18-7 shows recommended values for the FDIV field based on OSCCLK frequency. NOTE Programming or erasing the Flash memory cannot be performed if the bus clock runs at less than 1 MHz. Setting FDIV too high can destroy the Flash memory due to overstress. Setting FDIV too low can result in incomplete programming or erasure of the Flash memory cells. When the FCLKDIV register is written, the FDIVLD bit is set automatically. If the FDIVLD bit is 0, the FCLKDIV register has not been written since the last reset. If the FCLKDIV register has not been written, any Flash program or erase command loaded during a command write sequence will not execute and the ACCERR bit in the FSTAT register will set. S12XS-Family Reference Manual, Rev. 1.03 536 PRELIMINARY Freescale Semiconductor 256 KByte Flash Module (S12XFTMR256K1V1) 18.4.1.2 Command Write Sequence The Memory Controller will launch all valid Flash commands entered using a command write sequence. Before launching a command, the ACCERR and FPVIOL bits in the FSTAT register must be clear (see Section 18.3.2.7) and the CCIF flag should be tested to determine the status of the current command write sequence. If CCIF is 0, the previous command write sequence is still active, a new command write sequence cannot be started, and all writes to the FCCOB register are ignored. 18.4.1.2.1 Define FCCOB Contents The FCCOB parameter fields must be loaded with all required parameters for the Flash command being executed. Access to the FCCOB parameter fields is controlled via the CCOBIX bits in the FCCOBIX register (see Section 18.3.2.3). The contents of the FCCOB parameter fields are transferred to the Memory Controller when the user clears the CCIF command completion flag in the FSTAT register (writing 1 clears the CCIF to 0). The CCIF flag will remain clear until the Flash command has completed. Upon completion, the Memory Controller will return CCIF to 1 and the FCCOB register will be used to communicate any results. The flow for a generic command write sequence is shown in Figure 18-26. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 537 256 KByte Flash Module (S12XFTMR256K1V1) START Read: FCLKDIV register Clock Register Written Check FDIVLD Set? yes no Write: FCLKDIV register Note: FCLKDIV must be set after each reset Read: FSTAT register FCCOB Availability Check CCIF no Set? yes Access Error and Protection Violation Check ACCERR/ yes FPVIOL Set? no Write to FCCOBIX register to identify specific command parameter to load. Results from previous Command Write: FSTAT register Clear ACCERR/FPVIOL 0x30 Write to FCCOB register to load required command parameter. More yes Parameters? no Write: FSTAT register (to launch command) Clear CCIF 0x80 Read: FSTAT register Bit Polling for Command Completion Check CCIF Set? no yes EXIT Figure 18-26. Generic Flash Command Write Sequence Flowchart S12XS-Family Reference Manual, Rev. 1.03 538 PRELIMINARY Freescale Semiconductor 256 KByte Flash Module (S12XFTMR256K1V1) 18.4.1.3 Valid Flash Module Commands Table 18-28. Flash Commands by Mode FCMD Command 0x01 Erase Verify All Blocks 0x02 Erase Verify Block 0x03 Erase Verify P-Flash Section 0x04 Read Once 0x06 Program P-Flash 0x07 Program Once 0x08 Erase All Blocks 0x09 Erase Flash Block 0x0A Erase P-Flash Sector 0x0B Unsecure Flash 0x0C Verify Backdoor Access Key 0x0D Set User Margin Level 0x0E Set Field Margin Level 0x10 Erase Verify D-Flash Section 0x11 Program D-Flash 0x12 Erase D-Flash Sector 1 Unsecured Normal Single Chip mode. 2 Unsecured Normal Expanded mode. 3 Unsecured Special Single Chip mode. 4 Unsecured Special Mode. 5 Secured Normal Single Chip mode. 6 Secured Normal Expanded mode. 7 Secured Special Single Chip mode. 8 Secured Special Mode. Unsecured Secured NS1 NX2 SS3 ST4 NS5 NX6 SS7 ST8 ∗∗∗∗∗∗∗∗ ∗∗∗∗∗∗∗∗ ∗∗∗∗∗ ∗∗∗∗∗ ∗∗∗∗∗ ∗∗∗∗∗ ∗∗ ∗∗ ∗∗∗∗∗ ∗∗∗∗∗ ∗∗ ∗∗ ∗ ∗ ∗∗∗∗∗ ∗∗ ∗∗∗∗∗ ∗∗∗∗∗ ∗∗∗∗∗ S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 539 256 KByte Flash Module (S12XFTMR256K1V1) 18.4.1.4 P-Flash Commands Table 18-29 summarizes the valid P-Flash commands along with the effects of the commands on the PFlash block and other resources within the Flash module. Table 18-29. P-Flash Commands FCMD 0x01 0x02 0x03 0x04 0x06 0x07 0x08 0x09 0x0A 0x0B 0x0C 0x0D 0x0E Command Erase Verify All Blocks Erase Verify Block Erase Verify PFlash Section Read Once Program P-Flash Program Once Erase All Blocks Erase Flash Block Erase P-Flash Sector Unsecure Flash Verify Backdoor Access Key Set User Margin Level Set Field Margin Level Function on P-Flash Memory Verify that all P-Flash (and D-Flash) blocks are erased. Verify that a P-Flash block is erased. Verify that a given number of words starting at the address provided are erased. Read a dedicated 64 byte field in the nonvolatile information register in P-Flash block 0 that was previously programmed using the Program Once command. Program a phrase in a P-Flash block. Program a dedicated 64 byte field in the nonvolatile information register in P-Flash block 0 that is allowed to be programmed only once. Erase all P-Flash (and D-Flash) blocks. An erase of all Flash blocks is only possible when the FPLDIS, FPHDIS, and FPOPEN bits in the FPROT register and the DPOPEN bit in the DFPROT register are set prior to launching the command. Erase a P-Flash (or D-Flash) block. An erase of the full P-Flash block is only possible when FPLDIS, FPHDIS and FPOPEN bits in the FPROT register are set prior to launching the command. Erase all bytes in a P-Flash sector. Supports a method of releasing MCU security by erasing all P-Flash (and D-Flash) blocks and verifying that all P-Flash (and D-Flash) blocks are erased. Supports a method of releasing MCU security by verifying a set of security keys. Specifies a user margin read level for all P-Flash blocks. Specifies a field margin read level for all P-Flash blocks (special modes only). S12XS-Family Reference Manual, Rev. 1.03 540 PRELIMINARY Freescale Semiconductor 256 KByte Flash Module (S12XFTMR256K1V1) 18.4.1.5 D-Flash Commands Table 18-30 summarizes the valid D-Flash commands along with the effects of the commands on the DFlash block. Table 18-30. D-Flash Commands FCMD 0x01 0x02 0x08 0x09 0x0B 0x0D 0x0E 0x10 0x11 0x12 Command Erase Verify All Blocks Erase Verify Block Erase All Blocks Erase Flash Block Unsecure Flash Set User Margin Level Set Field Margin Level Erase Verify DFlash Section Program D-Flash Erase D-Flash Sector Function on D-Flash Memory Verify that all D-Flash (and P-Flash) blocks are erased. Verify that the D-Flash block is erased. Erase all D-Flash (and P-Flash) blocks. An erase of all Flash blocks is only possible when the FPLDIS, FPHDIS, and FPOPEN bits in the FPROT register and the DPOPEN bit in the DFPROT register are set prior to launching the command. Erase a D-Flash (or P-Flash) block. An erase of the full D-Flash block is only possible when DPOPEN bit in the DFPROT register is set prior to launching the command. Supports a method of releasing MCU security by erasing all D-Flash (and P-Flash) blocks and verifying that all D-Flash (and P-Flash) blocks are erased. Specifies a user margin read level for the D-Flash block. Specifies a field margin read level for the D-Flash block (special modes only). Verify that a given number of words starting at the address provided are erased. Program up to four words in the D-Flash block. Erase all bytes in a sector of the D-Flash block. S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 541 256 KByte Flash Module (S12XFTMR256K1V1) 18.4.2 Flash Command Description This section provides details of all available Flash commands launched by a command write sequence. The ACCERR bit in the FSTAT register will be set during the command write sequence if any of the following illegal steps are performed, causing the command not to be processed by the Memory Controller: • Starting any command write sequence that programs or erases Flash memory before initializing the FCLKDIV register • Writing an invalid command as part of the command write sequence • For additional possible errors, refer to the error handling table provided for each command If a Flash block is read during execution of an algorithm (CCIF = 0) on that same block, the read operation will return invalid data. If the SFDIF or DFDIF flags were not previously set when the invalid read operation occurred, both the SFDIF and DFDIF flags will be set and the FECCR registers will be loaded with the global address used in the invalid read operation with the data and parity fields set to all 0. If the ACCERR or FPVIOL bits are set in the FSTAT register, the user must clear these bits before starting any command write sequence (see Section 18.3.2.7). CAUTION A Flash word or phrase must be in the erased state before being programmed. Cumulative programming of bits within a Flash word or phrase is not allowed. S12XS-Family Reference Manual, Rev. 1.03 542 PRELIMINARY Freescale Semiconductor 256 KByte Flash Module (S12XFTMR256K1V1) 18.4.2.1 Erase Verify All Blocks Command The Erase Verify All Blocks command will verify that all P-Flash and D-Flash blocks have been erased. Table 18-31. Erase Verify All Blocks Command FCCOB Requirements CCOBIX[2:0] 000 FCCOB Parameters 0x01 Not required Upon clearing CCIF to launch the Erase Verify All Blocks command, the Memory Controller will verify that the entire Flash memory space is erased. The CCIF flag will set after the Erase Verify All Blocks operation has completed. Table 18-32. Erase Verify All Blocks Command Error Handling Register FSTAT Error Bit ACCERR FPVIOL MGSTAT1 MGSTAT0 Error Condition Set if CCOBIX[2:0] != 000 at command launch None Set if any errors have been encountered during the read Set if any non-correctable errors have been encountered during the read S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 543 256 KByte Flash Module (S12XFTMR256K1V1) 18.4.2.2 Erase Verify Block Command The Erase Verify Block command allows the user to verify that an entire P-Flash or D-Flash block has been erased. The FCCOB upper global address bits determine which block must be verified. Table 18-33. Erase Verify Block Command FCCOB Requirements CCOBIX[2:0] 000 FCCOB Parameters 0x02 Global address [22:16] of the Flash block to be verified. Upon clearing CCIF to launch the Erase Verify Block command, the Memory Controller will verify that the selected P-Flash or D-Flash block is erased. The CCIF flag will set after the Erase Verify Block operation has completed. Table 18-34. Erase Verify Block Command Error Handling Register FSTAT Error Bit ACCERR FPVIOL MGSTAT1 MGSTAT0 Error Condition Set if CCOBIX[2:0] != 000 at command launch Set if an invalid global address [22:16] is supplied None Set if any errors have been encountered during the read Set if any non-correctable errors have been encountered during the read S12XS-Family Reference Manual, Rev. 1.03 544 PRELIMINARY Freescale Semiconductor 256 KByte Flash Module (S12XFTMR256K1V1) 18.4.2.3 Erase Verify P-Flash Section Command The Erase Verify P-Flash Section command will verify that a section of code in the P-Flash memory is erased. The Erase Verify P-Flash Section command defines the starting point of the code to be verified and the number of phrases.256 Table 18-35. Erase Verify P-Flash Section Command FCCOB Requirements CCOBIX[2:0] FCCOB Parameters 000 0x03 Global address [22:16] of a P-Flash block 001 Global address [15:0] of the first phrase to be verified 010 Number of phrases to be verified Upon clearing CCIF to launch the Erase Verify P-Flash Section command, the Memory Controller will verify the selected section of Flash memory is erased. The CCIF flag will set after the Erase Verify P-Flash Section operation has completed. Table 18-36. Erase Verify P-Flash Section Command Error Handling Register FSTAT Error Bit ACCERR FPVIOL MGSTAT1 MGSTAT0 Error Condition Set if CCOBIX[2:0] != 010 at command launch Set if command not available in current mode (see Table 18-28) Set if an invalid global address [22:0] is supplied Set if a misaligned phrase address is supplied (global address [2:0] != 000) Set if the requested section crosses a 256 Kbyte boundary None Set if any errors have been encountered during the read Set if any non-correctable errors have been encountered during the read S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 545 256 KByte Flash Module (S12XFTMR256K1V1) 18.4.2.4 Read Once Command The Read Once command provides read access to a reserved 64 byte field (8 phrases) located in the nonvolatile information register of P-Flash block 0. The Read Once field is programmed using the Program Once command described in Section 18.4.2.6. Table 18-37. Read Once Command FCCOB Requirements CCOBIX[2:0] 000 001 010 011 100 101 FCCOB Parameters 0x04 Not Required Read Once phrase index (0x0000 - 0x0007) Read Once word 0 value Read Once word 1 value Read Once word 2 value Read Once word 3 value Upon clearing CCIF to launch the Read Once command, a Read Once phrase is fetched and stored in the FCCOB indexed register. The CCIF flag will set after the Read Once operation has completed. Valid phrase index values for the Read Once command range from 0x0000 to 0x0007. During execution of the Read Once command, any attempt to read addresses within P-Flash block will return invalid data. 128 Table 18-38. Read Once Command Error Handling Register FSTAT Error Bit ACCERR FPVIOL MGSTAT1 MGSTAT0 Error Condition Set if CCOBIX[2:0] != 001 at command launch Set if command not available in current mode (see Table 18-28) Set if an invalid phrase index is supplied None Set if any errors have been encountered during the read Set if any non-correctable errors have been encountered during the read S12XS-Family Reference Manual, Rev. 1.03 546 PRELIMINARY Freescale Semiconductor 256 KByte Flash Module (S12XFTMR256K1V1) 18.4.2.5 Program P-Flash Command The Program P-Flash operation will program a previously erased phrase in the P-Flash memory using an embedded algorithm. CAUTION A P-Flash phrase must be in the erased state before being programmed. Cumulative programming of bits within a Flash phrase is not allowed. Table 18-39. Program P-Flash Command FCCOB Requirements CCOBIX[2:0] FCCOB Parameters 000 0x06 Global address [22:16] to identify P-Flash block 001 Global address [15:0] of phrase location to be programmed1 010 Word 0 program value 011 Word 1 program value 100 Word 2 program value 101 Word 3 program value 1 Global address [2:0] must be 000 Upon clearing CCIF to launch the Program P-Flash command, the Memory Controller will program the data words to the supplied global address and will then proceed to verify the data words read back as expected. The CCIF flag will set after the Program P-Flash operation has completed. Table 18-40. Program P-Flash Command Error Handling Register FSTAT Error Bit ACCERR FPVIOL MGSTAT1 MGSTAT0 Error Condition Set if CCOBIX[2:0] != 101 at command launch Set if command not available in current mode (see Table 18-28) Set if an invalid global address [22:0] is supplied Set if a misaligned phrase address is supplied (global address [2:0] != 000) Set if the global address [22:0] points to a protected area Set if any errors have been encountered during the verify operation Set if any non-correctable errors have been encountered during the verify operation S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 547 256 KByte Flash Module (S12XFTMR256K1V1) 18.4.2.6 Program Once Command The Program Once command restricts programming to a reserved 64 byte field (8 phrases) in the nonvolatile information register located in P-Flash block 0. The Program Once reserved field can be read using the Read Once command as described in Section 18.4.2.4. The Program Once command must only be issued once since the nonvolatile information register in P-Flash block 0 cannot be erased. Table 18-41. Program Once Command FCCOB Requirements CCOBIX[2:0] 000 001 010 011 100 101 FCCOB Parameters 0x07 Not Required Program Once phrase index (0x0000 - 0x0007) Program Once word 0 value Program Once word 1 value Program Once word 2 value Program Once word 3 value Upon clearing CCIF to launch the Program Once command, the Memory Controller first verifies that the selected phrase is erased. If erased, then the selected phrase will be programmed and then verified with read back. The CCIF flag will remain clear, setting only after the Program Once operation has completed. The reserved nonvolatile information register accessed by the Program Once command cannot be erased and any attempt to program one of these phrases a second time will not be allowed. Valid phrase index values for the Program Once command range from 0x0000 to 0x0007. During execution of the Program Once command, any attempt to read addresses within P-Flash block 0 will return invalid data. R, Table 18-42. Program Once Command Error Handling Register Error Bit Error Condition Set if CCOBIX[2:0] != 101 at command launch FSTAT ACCERR FPVIOL Set if command not available in current mode (see Table 18-28) Set if an invalid phrase index is supplied Set if the requested phrase has already been programmed1 None MGSTAT1 Set if any errors have been encountered during the verify operation MGSTAT0 Set if any non-correctable errors have been encountered during the verify operation 1 If a Program Once phrase is initially programmed to 0xFFFF_FFFF_FFFF_FFFF, the Program Once command will be allowed to execute again on that same phrase. S12XS-Family Reference Manual, Rev. 1.03 548 PRELIMINARY Freescale Semiconductor 256 KByte Flash Module (S12XFTMR256K1V1) 18.4.2.7 Erase All Blocks Command The Erase All Blocks operation will erase the entire P-Flash and D-Flash memory space. Table 18-43. Erase All Blocks Command FCCOB Requirements CCOBIX[2:0] 000 FCCOB Parameters 0x08 Not required Upon clearing CCIF to launch the Erase All Blocks command, the Memory Controller will erase the entire Flash memory space and verify that it is erased. If the Memory Controller verifies that the entire Flash memory space was properly erased, security will be released. During the execution of this command (CCIF=0) the user must not write to any Flash module register. The CCIF flag will set after the Erase All Blocks operation has completed. Table 18-44. Erase All Blocks Command Error Handling Register FSTAT Error Bit ACCERR FPVIOL MGSTAT1 MGSTAT0 Error Condition Set if CCOBIX[2:0] != 000 at command launch Set if command not available in current mode (see Table 18-28) Set if any area of the P-Flash or D-Flash memory is protected Set if any errors have been encountered during the verify operation Set if any non-correctable errors have been encountered during the verify operation S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 549 256 KByte Flash Module (S12XFTMR256K1V1) 18.4.2.8 Erase Flash Block Command The Erase Flash Block operation will erase all addresses in a P-Flash or D-Flash block. Table 18-45. Erase Flash Block Command FCCOB Requirements CCOBIX[2:0] 000 001 FCCOB Parameters 0x09 Global address [22:16] to identify Flash block Global address [15:0] in Flash block to be erased Upon clearing CCIF to launch the Erase Flash Block command, the Memory Controller will erase the selected Flash block and verify that it is erased. The CCIF flag will set after the Erase Flash Block operation has completed. Table 18-46. Erase Flash Block Command Error Handling Register FSTAT Error Bit ACCERR FPVIOL MGSTAT1 MGSTAT0 Error Condition Set if CCOBIX[2:0] != 001 at command launch Set if command not available in current mode (see Table 18-28) Set if an invalid global address [22:16] is supplied Set if the supplied P-Flash address is not phrase-aligned or if the D-Flash address is not word-aligned Set if an area of the selected Flash block is protected Set if any errors have been encountered during the verify operation Set if any non-correctable errors have been encountered during the verify operation S12XS-Family Reference Manual, Rev. 1.03 550 PRELIMINARY Freescale Semiconductor 256 KByte Flash Module (S12XFTMR256K1V1) 18.4.2.9 Erase P-Flash Sector Command The Erase P-Flash Sector operation will erase all addresses in a P-Flash sector. Table 18-47. Erase P-Flash Sector Command FCCOB Requirements CCOBIX[2:0] 000 001 FCCOB Parameters 0x0A Global address [22:16] to identify P-Flash block to be erased Global address [15:0] anywhere within the sector to be erased. Refer to Section 18.1.2.1 for the P-Flash sector size. Upon clearing CCIF to launch the Erase P-Flash Sector command, the Memory Controller will erase the selected Flash sector and then verify that it is erased. The CCIF flag will be set after the Erase P-Flash Sector operation has completed. Table 18-48. Erase P-Flash Sector Command Error Handling Register FSTAT Error Bit ACCERR FPVIOL MGSTAT1 MGSTAT0 Error Condition Set if CCOBIX[2:0] != 001 at command launch Set if command not available in current mode (see Table 18-28) Set if an invalid global address [22:16] is supplied Set if a misaligned phrase address is supplied (global address [2:0] != 000) Set if the selected P-Flash sector is protected Set if any errors have been encountered during the verify operation Set if any non-correctable errors have been encountered during the verify operation S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 551 256 KByte Flash Module (S12XFTMR256K1V1) 18.4.2.10 Unsecure Flash Command The Unsecure Flash command will erase the entire P-Flash and D-Flash memory space and, if the erase is successful, will release security. Table 18-49. Unsecure Flash Command FCCOB Requirements CCOBIX[2:0] 000 FCCOB Parameters 0x0B Not required Upon clearing CCIF to launch the Unsecure Flash command, the Memory Controller will erase the entire P-Flash and D-Flash memory space and verify that it is erased. If the Memory Controller verifies that the entire Flash memory space was properly erased, security will be released. If the erase verify is not successful, the Unsecure Flash operation sets MGSTAT1 and terminates without changing the security state. During the execution of this command (CCIF=0) the user must not write to any Flash module register. The CCIF flag is set after the Unsecure Flash operation has completed. Table 18-50. Unsecure Flash Command Error Handling Register FSTAT Error Bit ACCERR FPVIOL MGSTAT1 MGSTAT0 Error Condition Set if CCOBIX[2:0] != 000 at command launch Set if command not available in current mode (see Table 18-28) Set if any area of the P-Flash or D-Flash memory is protected Set if any errors have been encountered during the verify operation Set if any non-correctable errors have been encountered during the verify operation S12XS-Family Reference Manual, Rev. 1.03 552 PRELIMINARY Freescale Semiconductor 256 KByte Flash Module (S12XFTMR256K1V1) 18.4.2.11 Verify Backdoor Access Key Command The Verify Backdoor Access Key command will only execute if it is enabled by the KEYEN bits in the FSEC register (see Table 18-9). The Verify Backdoor Access Key command releases security if usersupplied keys match those stored in the Flash security bytes of the Flash configuration field (see Table 183). Table 18-51. Verify Backdoor Access Key Command FCCOB Requirements CCOBIX[2:0] 000 001 010 011 100 FCCOB Parameters 0x0C Key 0 Key 1 Key 2 Key 3 Not required Upon clearing CCIF to launch the Verify Backdoor Access Key command, the Memory Controller will check the FSEC KEYEN bits to verify that this command is enabled. If not enabled, the Memory Controller sets the ACCERR bit in the FSTAT register and terminates. If the command is enabled, the Memory Controller compares the key provided in FCCOB to the backdoor comparison key in the Flash configuration field. If the backdoor keys match, security will be released. If the backdoor keys do not match, security is not released and all future attempts to execute the Verify Backdoor Access Key command are aborted (set ACCERR) until a power down reset occurs. The CCIF flag is set after the Verify Backdoor Access Key operation has completed. Table 18-52. Verify Backdoor Access Key Command Error Handling Register FSTAT Error Bit ACCERR FPVIOL MGSTAT1 MGSTAT0 Error Condition Set if CCOBIX[2:0] != 100 at command launch Set if an incorrect backdoor key is supplied Set if backdoor key access has not been enabled (KEYEN[1:0] != 10, see Section 18.3.2.2) Set if the backdoor key has mismatched since the last power down None None None S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 553 256 KByte Flash Module (S12XFTMR256K1V1) 18.4.2.12 Set User Margin Level Command The Set User Margin Level command causes the Memory Controller to set the margin level for future read operations of a specific P-Flash or D-Flash block. Table 18-53. Set User Margin Level Command FCCOB Requirements CCOBIX[2:0] 000 001 0x0D FCCOB Parameters Global address [22:16] to identify the Flash block Margin level setting Upon clearing CCIF to launch the Set User Margin Level command, the Memory Controller will set the user margin level for the targeted block and then set the CCIF flag. Valid margin level settings for the Set User Margin Level command are defined in Table 18-54. Table 18-54. Valid Set User Margin Level Settings CCOB (CCOBIX=001) Level Description 0x0000 Return to Normal Level 0x0001 User Margin-1 Level1 0x0002 User Margin-0 Level2 1 Read margin to the erased state 2 Read margin to the programmed state Register FSTAT Table 18-55. Set User Margin Level Command Error Handling Error Bit ACCERR FPVIOL MGSTAT1 MGSTAT0 Error Condition Set if CCOBIX[2:0] != 001 at command launch Set if command not available in current mode (see Table 18-28) Set if an invalid global address [22:16] is supplied Set if an invalid margin level setting is supplied None None None NOTE User margin levels can be used to check that Flash memory contents have adequate margin for normal level read operations. If unexpected results are encountered when checking Flash memory contents at user margin levels, a potential loss of information has been detected. S12XS-Family Reference Manual, Rev. 1.03 554 PRELIMINARY Freescale Semiconductor 256 KByte Flash Module (S12XFTMR256K1V1) 18.4.2.13 Set Field Margin Level Command The Set Field Margin Level command, valid in special modes only, causes the Memory Controller to set the margin level specified for future read operations of a specific P-Flash or D-Flash block. Table 18-56. Set Field Margin Level Command FCCOB Requirements CCOBIX[2:0] 000 001 0x0E FCCOB Parameters Global address [22:16] to identify the Flash block Margin level setting Upon clearing CCIF to launch the Set Field Margin Level command, the Memory Controller will set the field margin level for the targeted block and then set the CCIF flag. Valid margin level settings for the Set Field Margin Level command are defined in Table 18-57. Table 18-57. Valid Set Field Margin Level Settings CCOB (CCOBIX=001) Level Description 0x0000 Return to Normal Level 0x0001 User Margin-1 Level1 0x0002 User Margin-0 Level2 0x0003 Field Margin-1 Level1 0x0004 Field Margin-0 Level2 1 Read margin to the erased state 2 Read margin to the programmed state Register FSTAT Table 18-58. Set Field Margin Level Command Error Handling Error Bit ACCERR FPVIOL MGSTAT1 MGSTAT0 Error Condition Set if CCOBIX[2:0] != 001 at command launch Set if command not available in current mode (see Table 18-28) Set if an invalid global address [22:16] is supplied Set if an invalid margin level setting is supplied None None None S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 555 256 KByte Flash Module (S12XFTMR256K1V1) CAUTION Field margin levels must only be used during verify of the initial factory programming. NOTE Field margin levels can be used to check that Flash memory contents have adequate margin for data retention at the normal level setting. If unexpected results are encountered when checking Flash memory contents at field margin levels, the Flash memory contents should be erased and reprogrammed. S12XS-Family Reference Manual, Rev. 1.03 556 PRELIMINARY Freescale Semiconductor 256 KByte Flash Module (S12XFTMR256K1V1) 18.4.2.14 Erase Verify D-Flash Section Command The Erase Verify D-Flash Section command will verify that a section of code in the D-Flash is erased. The Erase Verify D-Flash Section command defines the starting point of the data to be verified and the number of words. Table 18-59. Erase Verify D-Flash Section Command FCCOB Requirements CCOBIX[2:0] FCCOB Parameters 000 0x10 Global address [22:16] to identify the D-Flash block 001 Global address [15:0] of the first word to be verified 010 Number of words to be verified Upon clearing CCIF to launch the Erase Verify D-Flash Section command, the Memory Controller will verify the selected section of D-Flash memory is erased. The CCIF flag will set after the Erase Verify DFlash Section operation has completed. Table 18-60. Erase Verify D-Flash Section Command Error Handling Register FSTAT Error Bit ACCERR FPVIOL MGSTAT1 MGSTAT0 Error Condition Set if CCOBIX[2:0] != 010 at command launch Set if command not available in current mode (see Table 18-28) Set if an invalid global address [22:0] is supplied Set if a misaligned word address is supplied (global address [0] != 0) Set if the requested section breaches the end of the D-Flash block None Set if any errors have been encountered during the read Set if any non-correctable errors have been encountered during the read S12XS-Family Reference Manual, Rev. 1.03 Freescale Semiconductor PRELIMINARY 557 256 KByte Flash Module (S12XFTMR256K1V1) 18.4.2.15 Program D-Flash Command The Program D-Flash operation programs one to four previously erased words in the D-Flash block. The Program D-Flash operation will confirm that the targeted location(s) were successfully programmed upon completion. CAUTION A Flash word must be in the erased state before being programmed. Cumulative programming of bits within a Flash word is not allowed. Table 18-61. Program D-Flash Command FCCOB Requirements CCOBIX[2:0] 000 001 010 011 100 101 FCCOB Parameters 0x11 Global address [22:16] to identify the D-Flash block Global address [15:0] of word to be programmed Word 0 program value Word 1 program value, if desired Word 2 program value, if desired Word 3 program value, if desired Upon clearing CCIF to launch the Program D-Flash command, the user-supplied words will be transferred to the Memory Controller and be programmed if the area is unprotected. The CCOBIX index value at Program D-Flash command launch determines how many words will be programmed in the D-Flash block. The CCIF flag is set when the operation has completed. Table 18-62. Program D-Flash Command Error Handling Register FSTAT Error Bit ACCERR FPVIOL MGSTAT1 MGSTAT0 Error Condition Set if CCOBIX[2:0] < 010 at command launch Set if CCOBIX[2:0] > 101 at command launch Set if command not available in current mode (see Table 18-28) Set if an invalid global address [22:0] is supplied Set if a misaligned word address is supplied (global address [0] != 0) Set if the requested group of words breaches the end of the D-Flash block Set if the selected area of the D-Flash memory is protected Set if any errors have been encountered during the verify operation Set if any non-correctable errors have been encountered during