MC9S08AW60 MC9S08AW48 MC9S08AW32 MC9S08AW16 Advance Information Data Sheet HCS08 Microcontrollers MC9S08AW60 Rev.1.0 1/2006 freescale.com MC9S08AW60/48/32/16 Features 8-Bit HCS08 Central Processor Unit (CPU) • • • • • • • 40-MHz HCS08 CPU (central processor unit) 20-MHz internal bus frequency HC08 instruction set with added BGND instruction Single-wire background debug mode interface Breakpoint capability to allow single breakpoint setting during in-circuit debugging (plus two more breakpoints in on-chip debug module) On-chip real-time in-circuit emulation (ICE) with two comparators (plus one in BDM), nine trigger modes, and on-chip bus capture buffer. Typically shows approximately 50 instructions before or after the trigger point. Support for up to 32 interrupt/reset sources Memory Options • • Up to 60 KB of on-chip in-circuit programmable FLASH memory with block protection and security options Up to 2 KB of on-chip RAM Clock Source Options • Clock source options include crystal, resonator, external clock, or internally generated clock with precision NVM trimming System Protection • • • • Optional computer operating properly (COP) reset Low-voltage detection with reset or interrupt Illegal opcode detection with reset Illegal address detection with reset (some devices don’t have illegal addresses) Power-Saving Modes • Wait plus two stops Peripherals • • • ADC — 16-channel, 10-bit analog-to-digital converter with automatic compare function SCI — Two serial communications interface modules with optional 13-bit break SPI — Serial peripheral interface module • • • IIC — Inter-integrated circuit bus module to operate at up to 100 kbps with maximum bus loading; capable of higher baudrates with reduced loading Timers — One 2-channel and one 6-channel 16-bit timer/pulse-width modulator (TPM) module: Selectable input capture, output compare, and edge-aligned PWM capability on each channel. Each timer module may be configured for buffered, centered PWM (CPWM) on all channels KBI — 8-pin keyboard interrupt module Input/Output • • • • • • Up to 54 general-purpose input/output (I/O) pins Software selectable pullups on ports when used as inputs Software selectable slew rate control on ports when used as outputs Software selectable drive strength on ports when used as outputs Master reset pin and power-on reset (POR) Internal pullup on RESET, IRQ, and BKGD/MS pins to reduce customer system cost Package Options: MC9S08AW60/48/32 • • • • 64-pin quad flat package (QFP) 64-pin low-profile quad flat package (LQFP) 48-pin low-profile quad flat package (QFN) 44-pin low-profile quad flat package (LQFP) MC9S08AW16 • • 48-pin low-profile quad flat package (QFN) 44-pin low-profile quad flat package (LQFP) MC9S08AW60 Data Sheet, Rev.1.0 4 Freescale Semiconductor MC9S08AW60 Advance Information Data Sheet Covers MC9S08AW60 MC9S08AW48 MC9S08AW32 MC9S08AW16 MC9S08AW60 Rev.1.0 1/2006 This document contains information on a new product. Specifications and information herein are subject to change without notice. Revision History To provide the most up-to-date information, the revision of our documents on the World Wide Web will be the most current. Your printed copy may be an earlier revision. To verify you have the latest information available, refer to: http://freescale.com/ The following revision history table summarizes changes contained in this document. For your convenience, the page number designators have been linked to the appropriate location. Revision Number Revision Date 1.0 1/30/2006 Description of Changes Initial external release. This product incorporates SuperFlash® technology licensed from SST. Freescale™ and the Freescale logo are trademarks of Freescale Semiconductor, Inc. © Freescale Semiconductor, Inc., 2006. All rights reserved. Chapters Chapter 1 Introduction...................................................................................... 19 Chapter 2 Pins and Connections ..................................................................... 23 Chapter 3 Modes of Operation ......................................................................... 33 Chapter 4 Memory ............................................................................................. 39 Chapter 5 Resets, Interrupts, and System Configuration ............................. 63 Chapter 6 Parallel Input/Output ....................................................................... 79 Chapter 7 Central Processor Unit (S08CPUV2) ............................................ 107 Chapter 8 Internal Clock Generator (S08ICGV4) .......................................... 127 Chapter 9 Keyboard Interrupt (S08KBIV1) .................................................... 155 Chapter 10 Timer/PWM (S08TPMV2) ............................................................... 163 Chapter 11 Serial Communications Interface (S08SCIV2)............................. 179 Chapter 12 Serial Peripheral Interface (S08SPIV3) ........................................ 197 Chapter 13 Inter-Integrated Circuit (S08IICV1) ............................................... 215 Chapter 14 Analog-to-Digital Converter (S08ADC10V1)................................ 231 Chapter 15 Development Support ................................................................... 257 Appendix A Electrical Characteristics and Timing Specifications ............... 279 Appendix B Ordering Information and Mechanical Drawings....................... 305 MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 7 Chapter 1 Introduction 1.1 1.2 1.3 Overview .........................................................................................................................................19 MCU Block Diagrams .....................................................................................................................19 System Clock Distribution ..............................................................................................................21 Chapter 2 Pins and Connections 2.1 2.2 2.3 Introduction .....................................................................................................................................23 Device Pin Assignment ...................................................................................................................24 Recommended System Connections ...............................................................................................26 2.3.1 Power (VDD, 2 x VSS, VDDAD, VSSAD) .........................................................................28 2.3.2 Oscillator (XTAL, EXTAL) ............................................................................................28 RESET ............................................................................................................................28 2.3.3 2.3.4 Background/Mode Select (BKGD/MS) .........................................................................29 2.3.5 ADC Reference Pins (VREFH, VREFL) ...........................................................................29 2.3.6 External Interrupt Pin (IRQ) ...........................................................................................29 2.3.7 General-Purpose I/O and Peripheral Ports .....................................................................30 Chapter 3 Modes of Operation 3.1 3.2 3.3 3.4 3.5 3.6 Introduction .....................................................................................................................................33 Features ...........................................................................................................................................33 Run Mode ........................................................................................................................................33 Active Background Mode ................................................................................................................33 Wait Mode .......................................................................................................................................34 Stop Modes ......................................................................................................................................34 3.6.1 Stop2 Mode ....................................................................................................................35 3.6.2 Stop3 Mode ....................................................................................................................36 3.6.3 Active BDM Enabled in Stop Mode ...............................................................................36 3.6.4 LVD Enabled in Stop Mode ...........................................................................................37 3.6.5 On-Chip Peripheral Modules in Stop Modes .................................................................37 Chapter 4 Memory 4.1 4.2 4.3 4.4 MC9S08AW60/48/32/16 Memory Map ..........................................................................................39 4.1.1 Reset and Interrupt Vector Assignments ........................................................................42 Register Addresses and Bit Assignments ........................................................................................43 RAM ................................................................................................................................................49 FLASH ............................................................................................................................................49 4.4.1 Features ...........................................................................................................................50 MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 9 4.5 4.6 4.4.2 Program and Erase Times ...............................................................................................50 4.4.3 Program and Erase Command Execution .......................................................................51 4.4.4 Burst Program Execution ...............................................................................................52 4.4.5 Access Errors ..................................................................................................................54 4.4.6 FLASH Block Protection ...............................................................................................54 4.4.7 Vector Redirection ..........................................................................................................55 Security ............................................................................................................................................55 FLASH Registers and Control Bits .................................................................................................57 4.6.1 FLASH Clock Divider Register (FCDIV) ......................................................................57 4.6.2 FLASH Options Register (FOPT and NVOPT) .............................................................58 4.6.3 FLASH Configuration Register (FCNFG) .....................................................................59 4.6.4 FLASH Protection Register (FPROT and NVPROT) ....................................................60 4.6.5 FLASH Status Register (FSTAT) ...................................................................................60 4.6.6 FLASH Command Register (FCMD) ............................................................................62 Chapter 5 Resets, Interrupts, and System Configuration 5.1 5.2 5.3 5.4 5.5 5.6 5.7 5.8 5.9 Introduction .....................................................................................................................................63 Features ...........................................................................................................................................63 MCU Reset ......................................................................................................................................63 Computer Operating Properly (COP) Watchdog .............................................................................64 Interrupts .........................................................................................................................................64 5.5.1 Interrupt Stack Frame .....................................................................................................65 5.5.2 External Interrupt Request (IRQ) Pin .............................................................................66 5.5.3 Interrupt Vectors, Sources, and Local Masks .................................................................67 Low-Voltage Detect (LVD) System ................................................................................................69 5.6.1 Power-On Reset Operation .............................................................................................69 5.6.2 LVD Reset Operation .....................................................................................................69 5.6.3 LVD Interrupt Operation ................................................................................................69 5.6.4 Low-Voltage Warning (LVW) ........................................................................................69 Real-Time Interrupt (RTI) ...............................................................................................................69 MCLK Output .................................................................................................................................70 Reset, Interrupt, and System Control Registers and Control Bits ...................................................70 5.9.1 Interrupt Pin Request Status and Control Register (IRQSC) .........................................71 5.9.2 System Reset Status Register (SRS) ...............................................................................72 5.9.3 System Background Debug Force Reset Register (SBDFR) ..........................................73 5.9.4 System Options Register (SOPT) ...................................................................................73 5.9.5 System MCLK Control Register (SMCLK) ...................................................................74 5.9.6 System Device Identification Register (SDIDH, SDIDL) ..............................................75 5.9.7 System Real-Time Interrupt Status and Control Register (SRTISC) .............................76 5.9.8 System Power Management Status and Control 1 Register (SPMSC1) .........................77 5.9.9 System Power Management Status and Control 2 Register (SPMSC2) .........................78 MC9S08AW60 Data Sheet, Rev.1.0 10 Freescale Semiconductor Chapter 6 Parallel Input/Output 6.1 6.2 6.3 6.4 6.5 6.6 6.7 Introduction .....................................................................................................................................79 Features ...........................................................................................................................................79 Pin Descriptions ..............................................................................................................................80 6.3.1 Port A ..............................................................................................................................80 6.3.2 Port B ..............................................................................................................................80 6.3.3 Port C ..............................................................................................................................81 6.3.4 Port D ..............................................................................................................................81 6.3.5 Port E ..............................................................................................................................82 6.3.6 Port F ..............................................................................................................................83 6.3.7 Port G ..............................................................................................................................83 Parallel I/O Control .........................................................................................................................84 Pin Control ......................................................................................................................................85 6.5.1 Internal Pullup Enable ....................................................................................................85 6.5.2 Output Slew Rate Control Enable ..................................................................................85 6.5.3 Output Drive Strength Select ..........................................................................................85 Pin Behavior in Stop Modes ............................................................................................................86 Parallel I/O and Pin Control Registers ............................................................................................86 6.7.1 Port A I/O Registers (PTAD and PTADD) .....................................................................86 6.7.2 Port A Pin Control Registers (PTAPE, PTASE, PTADS) ..............................................87 6.7.3 Port B I/O Registers (PTBD and PTBDD) .....................................................................89 6.7.4 Port B Pin Control Registers (PTBPE, PTBSE, PTBDS) ..............................................90 6.7.5 Port C I/O Registers (PTCD and PTCDD) .....................................................................92 6.7.6 Port C Pin Control Registers (PTCPE, PTCSE, PTCDS) ..............................................93 6.7.7 Port D I/O Registers (PTDD and PTDDD) ....................................................................95 6.7.8 Port D Pin Control Registers (PTDPE, PTDSE, PTDDS) .............................................96 6.7.9 Port E I/O Registers (PTED and PTEDD) ......................................................................98 6.7.10 Port E Pin Control Registers (PTEPE, PTESE, PTEDS) ...............................................99 6.7.11 Port F I/O Registers (PTFD and PTFDD) ....................................................................101 6.7.12 Port F Pin Control Registers (PTFPE, PTFSE, PTFDS) ..............................................102 6.7.13 Port G I/O Registers (PTGD and PTGDD) ..................................................................104 6.7.14 Port G Pin Control Registers (PTGPE, PTGSE, PTGDS) ...........................................105 Chapter 7 Central Processor Unit (S08CPUV2) 7.1 7.2 Introduction ...................................................................................................................................107 7.1.1 Features .........................................................................................................................107 Programmer’s Model and CPU Registers .....................................................................................108 7.2.1 Accumulator (A) ...........................................................................................................108 7.2.2 Index Register (H:X) ....................................................................................................108 7.2.3 Stack Pointer (SP) .........................................................................................................109 7.2.4 Program Counter (PC) ..................................................................................................109 7.2.5 Condition Code Register (CCR) ...................................................................................109 MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 11 7.3 7.4 7.5 Addressing Modes .........................................................................................................................110 7.3.1 Inherent Addressing Mode (INH) ................................................................................111 7.3.2 Relative Addressing Mode (REL) ................................................................................111 7.3.3 Immediate Addressing Mode (IMM) ...........................................................................111 7.3.4 Direct Addressing Mode (DIR) ....................................................................................111 7.3.5 Extended Addressing Mode (EXT) ..............................................................................111 7.3.6 Indexed Addressing Mode ............................................................................................111 Special Operations .........................................................................................................................112 7.4.1 Reset Sequence .............................................................................................................113 7.4.2 Interrupt Sequence ........................................................................................................113 7.4.3 Wait Mode Operation ...................................................................................................114 7.4.4 Stop Mode Operation ...................................................................................................114 7.4.5 BGND Instruction ........................................................................................................114 HCS08 Instruction Set Summary ..................................................................................................115 Chapter 8 Internal Clock Generator (S08ICGV4) 8.1 8.2 8.3 8.4 Introduction ...................................................................................................................................129 8.1.1 Features .........................................................................................................................130 8.1.2 Modes of Operation ......................................................................................................130 External Signal Description ..........................................................................................................131 8.2.1 EXTAL — External Reference Clock / Oscillator Input ..............................................131 8.2.2 XTAL — Oscillator Output ..........................................................................................131 8.2.3 External Clock Connections .........................................................................................131 8.2.4 External Crystal/Resonator Connections ......................................................................132 Register Definition ........................................................................................................................132 8.3.1 ICG Control Register 1 (ICGC1) .................................................................................133 8.3.2 ICG Control Register 2 (ICGC2) .................................................................................135 8.3.3 ICG Status Register 1 (ICGS1) ....................................................................................136 8.3.4 ICG Status Register 2 (ICGS2) ....................................................................................137 8.3.5 ICG Filter Registers (ICGFLTU, ICGFLTL) ...............................................................137 8.3.6 ICG Trim Register (ICGTRM) .....................................................................................138 Functional Description ..................................................................................................................138 8.4.1 Off Mode (Off) .............................................................................................................139 8.4.2 Self-Clocked Mode (SCM) ...........................................................................................139 8.4.3 FLL Engaged, Internal Clock (FEI) Mode ...................................................................140 8.4.4 FLL Engaged Internal Unlocked ..................................................................................141 8.4.5 FLL Engaged Internal Locked ......................................................................................141 8.4.6 FLL Bypassed, External Clock (FBE) Mode ...............................................................141 8.4.7 FLL Engaged, External Clock (FEE) Mode .................................................................141 8.4.8 FLL Lock and Loss-of-Lock Detection ........................................................................142 8.4.9 FLL Loss-of-Clock Detection ......................................................................................143 8.4.10 Clock Mode Requirements ...........................................................................................144 8.4.11 Fixed Frequency Clock .................................................................................................145 8.4.12 High Gain Oscillator .....................................................................................................145 MC9S08AW60 Data Sheet, Rev.1.0 12 Freescale Semiconductor 8.5 Initialization/Application Information ..........................................................................................145 8.5.1 Introduction ..................................................................................................................145 8.5.2 Example #1: External Crystal = 32 kHz, Bus Frequency = 4.19 MHz ........................147 8.5.3 Example #2: External Crystal = 4 MHz, Bus Frequency = 20 MHz ............................149 8.5.4 Example #3: No External Crystal Connection, 5.4 MHz Bus Frequency ....................151 8.5.5 Example #4: Internal Clock Generator Trim ................................................................153 Chapter 9 Keyboard Interrupt (S08KBIV1) 9.1 9.2 9.3 9.4 9.5 Introduction ...................................................................................................................................155 Keyboard Pin Sharing ....................................................................................................................155 Features .........................................................................................................................................156 9.3.1 KBI Block Diagram ......................................................................................................158 Register Definition ........................................................................................................................158 9.4.1 KBI Status and Control Register (KBI1SC) .................................................................159 9.4.2 KBI Pin Enable Register (KBI1PE) .............................................................................160 Functional Description ..................................................................................................................160 9.5.1 Pin Enables ...................................................................................................................160 9.5.2 Edge and Level Sensitivity ...........................................................................................160 9.5.3 KBI Interrupt Controls .................................................................................................161 Chapter 10 Timer/PWM (S08TPMV2) 10.1 Introduction ...................................................................................................................................163 10.2 Features .........................................................................................................................................163 10.2.1 Block Diagram ..............................................................................................................165 10.3 External Signal Description ..........................................................................................................166 10.3.1 External TPM Clock Sources .......................................................................................166 10.3.2 TPMxCHn — TPMx Channel n I/O Pins .....................................................................166 10.4 Register Definition ........................................................................................................................166 10.4.1 Timer x Status and Control Register (TPMxSC) ..........................................................167 10.4.2 Timer x Counter Registers (TPMxCNTH:TPMxCNTL) .............................................168 10.4.3 Timer x Counter Modulo Registers (TPMxMODH:TPMxMODL) .............................169 10.4.4 Timer x Channel n Status and Control Register (TPMxCnSC) ....................................170 10.4.5 Timer x Channel Value Registers (TPMxCnVH:TPMxCnVL) ....................................171 10.5 Functional Description ..................................................................................................................172 10.5.1 Counter .........................................................................................................................172 10.5.2 Channel Mode Selection ...............................................................................................173 10.5.3 Center-Aligned PWM Mode ........................................................................................175 10.6 TPM Interrupts ..............................................................................................................................176 10.6.1 Clearing Timer Interrupt Flags .....................................................................................176 10.6.2 Timer Overflow Interrupt Description ..........................................................................176 10.6.3 Channel Event Interrupt Description ............................................................................177 10.6.4 PWM End-of-Duty-Cycle Events .................................................................................177 MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 13 Chapter 11 Serial Communications Interface (S08SCIV2) 11.1 Introduction ...................................................................................................................................179 11.1.1 Features .........................................................................................................................181 11.1.2 Modes of Operation ......................................................................................................181 11.1.3 Block Diagram ..............................................................................................................182 11.2 Register Definition ........................................................................................................................184 11.2.1 SCI Baud Rate Registers (SCIxBDH, SCIxBHL) ........................................................184 11.2.2 SCI Control Register 1 (SCIxC1) .................................................................................185 11.2.3 SCI Control Register 2 (SCIxC2) .................................................................................186 11.2.4 SCI Status Register 1 (SCIxS1) ....................................................................................187 11.2.5 SCI Status Register 2 (SCIxS2) ....................................................................................189 11.2.6 SCI Control Register 3 (SCIxC3) .................................................................................189 11.2.7 SCI Data Register (SCIxD) ..........................................................................................190 11.3 Functional Description ..................................................................................................................191 11.3.1 Baud Rate Generation ...................................................................................................191 11.3.2 Transmitter Functional Description ..............................................................................191 11.3.3 Receiver Functional Description ..................................................................................193 11.3.4 Interrupts and Status Flags ...........................................................................................194 11.4 Additional SCI Functions ..............................................................................................................195 11.4.1 8- and 9-Bit Data Modes ..............................................................................................195 11.4.2 Stop Mode Operation ...................................................................................................196 11.4.3 Loop Mode ...................................................................................................................196 11.4.4 Single-Wire Operation ..................................................................................................196 Chapter 12 Serial Peripheral Interface (S08SPIV3) 12.1 Introduction ...................................................................................................................................199 12.1.1 Features .........................................................................................................................200 12.1.2 Block Diagrams ............................................................................................................200 12.1.3 SPI Baud Rate Generation ............................................................................................202 12.2 External Signal Description ..........................................................................................................203 12.2.1 SPSCK — SPI Serial Clock .........................................................................................203 12.2.2 MOSI — Master Data Out, Slave Data In ....................................................................203 12.2.3 MISO — Master Data In, Slave Data Out ....................................................................203 12.2.4 SS — Slave Select ........................................................................................................203 12.3 Register Definition ........................................................................................................................204 12.3.1 SPI Control Register 1 (SPI1C1) ..................................................................................204 12.3.2 SPI Control Register 2 (SPI1C2) ..................................................................................205 12.3.3 SPI Baud Rate Register (SPI1BR) ...............................................................................206 12.3.4 SPI Status Register (SPI1S) ..........................................................................................207 12.3.5 SPI Data Register (SPI1D) ...........................................................................................208 12.4 Functional Description ..................................................................................................................208 12.4.1 SPI Clock Formats ........................................................................................................209 12.4.2 SPI Interrupts ................................................................................................................211 MC9S08AW60 Data Sheet, Rev.1.0 14 Freescale Semiconductor 12.4.3 Mode Fault Detection ...................................................................................................212 12.5 Initialization/Application Information ..........................................................................................212 12.5.1 SPI Module Initialization Example ..............................................................................212 Chapter 13 Inter-Integrated Circuit (S08IICV1) 13.1 Introduction ...................................................................................................................................215 13.1.1 Features .........................................................................................................................217 13.1.2 Modes of Operation ......................................................................................................217 13.1.3 Block Diagram ..............................................................................................................218 13.2 External Signal Description ..........................................................................................................218 13.2.1 SCL — Serial Clock Line .............................................................................................218 13.2.2 SDA — Serial Data Line ..............................................................................................218 13.3 Register Definition ........................................................................................................................218 13.3.1 IIC Address Register (IIC1A) .......................................................................................219 13.3.2 IIC Frequency Divider Register (IIC1F) ......................................................................219 13.3.3 IIC Control Register (IIC1C) ........................................................................................222 13.3.4 IIC Status Register (IIC1S) ..........................................................................................223 13.3.5 IIC Data I/O Register (IIC1D) ......................................................................................224 13.4 Functional Description ..................................................................................................................225 13.4.1 IIC Protocol ..................................................................................................................225 13.5 Resets ............................................................................................................................................228 13.6 Interrupts .......................................................................................................................................228 13.6.1 Byte Transfer Interrupt .................................................................................................229 13.6.2 Address Detect Interrupt ...............................................................................................229 13.6.3 Arbitration Lost Interrupt .............................................................................................229 Chapter 14 Analog-to-Digital Converter (S08ADC10V1) 14.1 Overview .......................................................................................................................................231 14.2 Channel Assignments ....................................................................................................................231 14.2.1 Alternate Clock .............................................................................................................232 14.2.2 Hardware Trigger ..........................................................................................................232 14.2.3 Features .........................................................................................................................234 14.2.4 Block Diagram ..............................................................................................................234 14.3 External Signal Description ..........................................................................................................235 14.3.1 Analog Power (VDDAD) ................................................................................................236 14.3.2 Analog Ground (VSSAD) ..............................................................................................236 14.3.3 Voltage Reference High (VREFH) .................................................................................236 14.3.4 Voltage Reference Low (VREFL) ..................................................................................236 14.3.5 Analog Channel Inputs (ADx) ......................................................................................236 14.4 Register Definition ........................................................................................................................236 14.4.1 Status and Control Register 1 (ADC1SC1) ..................................................................236 14.4.2 Status and Control Register 2 (ADC1SC2) ..................................................................238 14.4.3 Data Result High Register (ADC1RH) ........................................................................239 MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 15 14.4.4 Data Result Low Register (ADC1RL) ..........................................................................239 14.4.5 Compare Value High Register (ADC1CVH) ................................................................240 14.4.6 Compare Value Low Register (ADC1CVL) .................................................................240 14.4.7 Configuration Register (ADC1CFG) ............................................................................240 14.4.8 Pin Control 1 Register (APCTL1) ................................................................................242 14.4.9 Pin Control 2 Register (APCTL2) ................................................................................243 14.4.10 Pin Control 3 Register (APCTL3) ................................................................................244 14.5 Functional Description ..................................................................................................................245 14.5.1 Clock Select and Divide Control ..................................................................................245 14.5.2 Input Select and Pin Control .........................................................................................246 14.5.3 Hardware Trigger ..........................................................................................................246 14.5.4 Conversion Control .......................................................................................................246 14.5.5 Automatic Compare Function ......................................................................................249 14.5.6 MCU Wait Mode Operation .........................................................................................249 14.5.7 MCU Stop3 Mode Operation .......................................................................................249 14.5.8 MCU Stop1 and Stop2 Mode Operation ......................................................................250 14.6 Initialization Information ..............................................................................................................250 14.6.1 ADC Module Initialization Example ...........................................................................250 14.7 Application Information ................................................................................................................252 14.7.1 External Pins and Routing ............................................................................................252 14.7.2 Sources of Error ............................................................................................................254 Chapter 15 Development Support 15.1 Introduction ...................................................................................................................................257 15.1.1 Features .........................................................................................................................257 15.2 Background Debug Controller (BDC) ..........................................................................................258 15.2.1 BKGD Pin Description .................................................................................................258 15.2.2 Communication Details ................................................................................................259 15.2.3 BDC Commands ...........................................................................................................263 15.2.4 BDC Hardware Breakpoint ..........................................................................................265 15.3 On-Chip Debug System (DBG) ....................................................................................................266 15.3.1 Comparators A and B ...................................................................................................266 15.3.2 Bus Capture Information and FIFO Operation .............................................................266 15.3.3 Change-of-Flow Information ........................................................................................267 15.3.4 Tag vs. Force Breakpoints and Triggers .......................................................................267 15.3.5 Trigger Modes ..............................................................................................................268 15.3.6 Hardware Breakpoints ..................................................................................................270 15.4 Register Definition ........................................................................................................................270 15.4.1 BDC Registers and Control Bits ...................................................................................270 15.4.2 System Background Debug Force Reset Register (SBDFR) ........................................272 15.4.3 DBG Registers and Control Bits ..................................................................................273 MC9S08AW60 Data Sheet, Rev.1.0 16 Freescale Semiconductor Appendix A Electrical Characteristics and Timing Specifications A.1 A.2 A.3 A.4 A.5 A.6 A.7 A.8 A.9 A.10 A.11 A.12 A.13 Introduction ....................................................................................................................................279 Parameter Classification.................................................................................................................279 Absolute Maximum Ratings...........................................................................................................279 Thermal Characteristics..................................................................................................................281 ESD Protection and Latch-Up Immunity .......................................................................................282 DC Characteristics..........................................................................................................................283 Supply Current Characteristics.......................................................................................................287 ADC Characteristics.......................................................................................................................289 Internal Clock Generation Module Characteristics ........................................................................292 A.9.1 ICG Frequency Specifications.......................................................................................293 AC Characteristics..........................................................................................................................295 A.10.1 Control Timing ..............................................................................................................295 A.10.2 Timer/PWM (TPM) Module Timing.............................................................................296 SPI Characteristics .........................................................................................................................298 FLASH Specifications....................................................................................................................301 EMC Performance..........................................................................................................................302 A.13.1 Radiated Emissions .......................................................................................................302 A.13.2 Conducted Transient Susceptibility...............................................................................302 Appendix B Ordering Information and Mechanical Drawings B.1 Ordering Information .....................................................................................................................305 B.2 Orderable Part Numbering System ................................................................................................305 B.3 Mechanical Drawings.....................................................................................................................305 MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 17 MC9S08AW60 Data Sheet, Rev.1.0 18 Freescale Semiconductor Chapter 1 Introduction 1.1 Overview The MC9S08AW60, MC9S08AW48, MC9S08AW32, and MC9S08AW16 are members of the low-cost, high-performance HCS08 Family of 8-bit microcontroller units (MCUs). All MCUs in the family use the enhanced HCS08 core and are available with a variety of modules, memory sizes, memory types, and package types. Refer to Table 1-1 for memory sizes and package types. Table 1-2 summarizes the peripheral availability per package type for the devices available in the MC9S08AW60/48/32/16 series. Table 1-1. Devices in the MC9S08AW60/48/32/16 Series Device FLASH MC9S08AW60 63,280 MC9S08AW48 49,152 MC9S08AW32 32,768 MC9S08AW16 16,384 RAM 2048 1024 Package 64 QFP 64 LQFP 48 QFN 44 LQFP Table 1-2. Peripherals Available per Package Type Package Options 1.2 Feature 64-pin 48-pin 44-pin ADC 16-ch 8-ch 8-ch IIC yes yes yes IRQ yes yes yes KBI1 8 7 6 SCI1 yes yes yes SCI2 yes yes yes SPI1 yes yes yes TPM1 6-ch 4-ch 4-ch TPM1CLK yes no no TPM2 2-ch 2-ch 2-ch TPM2CLK yes no no I/O pins 54 38 34 MCU Block Diagrams The block diagram shows the structure of the MC9S08AW60/48/32/16 MCU. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 19 HCS08 CORE BDC DEBUG MODULE (DBG) RTI COP IRQ LVD SERIAL COMMUNICATIONS INTERFACE MODULE (SCI2) IIC MODULE (IIC1) 10-BIT ANALOG-TO-DIGITAL CONVERTER (ADC1) TxD2 SDA1 SCL1 6-CHANNEL TIMER/PWM MODULE (TPM1) INTERNAL CLOCK GENERATOR (ICG) LOW-POWER OSCILLATOR SERIAL COMMUNICATIONS INTERFACE MODULE (SCI1) VOLTAGE REGULATOR 2-CHANNEL TIMER/PWM MODULE (TPM2) SPSCK1 MOSI1 PTE7/SPSCK1 MISO1 SS1 TPM1CLK TPM1CH5– TPM1CH0 RxD1 TxD1 PORT E USER RAM AW60/48/32 = 2048 BYTES AW16 = 1024 BYTES PTD7/AD1P15/KBI1P7 PTD6/AD1P14/TPM1CLK PTD5/AD1P13 PTD4/AD1P12/TPM2CLK PTD3/AD1P11/KBI1P6 PTD2/AD1P10/KBI1P5 PTD1/AD1P9 PTD0/AD1P8 8 8 AD1P15–AD1P8 USER FLASH (AW60 = 63,280 BYTES) (AW48 = 49,152 BYTES) (AW32 = 32,768 BYTES) (AW16 = 16,384 BYTES) SERIAL PERIPHERAL INTERFACE MODULE (SPI1) PTC6 PTC5/RxD2 PTC4 PTC3/TxD2 PTC2/MCLK PTC1/SDA1 PTC0/SCL1 RxD2 AD1P7–AD1P0 VSSAD VREFL VREFH 6 TPM2CLK PORT F VSS PTB7/AD1P7– PTB0/AD1P0 PORT C RESETS AND INTERRUPTS MODES OF OPERATION POWER MANAGEMENT VDDAD VDD 8 PORT D IRQ PTA7– PTA0 HCS08 SYSTEM CONTROL TPM2CH1–TPM2CH0 2 KBI1P7–KBI1P5 3 8-BIT KEYBOARD INTERRUPT MODULE (KBI1) KBI1P4–KBI1P0 EXTAL XTAL 5 NOTES: 1. Port pins are software configurable with pullup device if input port. 2. Pin contains software configurable pullup/pulldown device if IRQ is enabled (IRQPE = 1). Pulldown is enabled if rising edge detect is selected (IRQEDG = 1) 3. IRQ does not have a clamp diode to VDD. IRQ should not be driven above VDD. 4. Pin contains integrated pullup device. 5. Pins PTD7, PTD3, PTD2, and PTG4 contain both pullup and pulldown devices. Pulldown enabled when KBI is enabled (KBIPEn = 1) and rising edge is selected (KBEDGn = 1). PORT G RESET 8 CPU PORT B BKGD/MS PORT A Chapter 1 Introduction PTE6/MOSI1 PTE5/MISO1 PTE4/SS1 PTE3/TPM1CH1 PTE2/TPM1CH0 PTE1/RxD1 PTE0/TxD1 PTF7 PTF6 PTF5/TPM2CH1 PTF4/TPM2CH0 PTF3/TPM1CH5 PTF2/TPM1CH4 PTF1/TPM1CH3 PTF0/TPM1CH2 PTG6/EXTAL PTG5/XTAL PTG4/KBI1P4 PTG3/KBI1P3 PTG2/KBI1P2 PTG1/KBI1P1 PTG0/KBI1P0 Figure 1-1. MC9S08AW60/48/32/16 Block Diagram MC9S08AW60 Data Sheet, Rev.1.0 20 Freescale Semiconductor Chapter 1 Introduction Table 1-3 lists the functional versions of the on-chip modules. Table 1-3. Versions of On-Chip Modules Module Version Analog-to-Digital Converter (ADC) 1 (ICG) 4 (IIC) 1 Keyboard Interrupt (KBI) 1 Serial Communications Interface (SCI) 2 Serial Peripheral Interface (SPI) 3 (TPM) 2 Internal Clock Generator Inter-Integrated Circuit Timer Pulse-Width Modulator 1.3 Central Processing Unit (CPU) 2 Debug Module (DBG) 2 System Clock Distribution ICGERCLK SYSTEM CONTROL LOGIC TPM1 TPM2 IIC1 SCI1 SCI2 SPI1 RTI FFE ÷2 ICG FIXED FREQ CLOCK (XCLK) ICGOUT ÷2 BUSCLK ICGLCLK* CPU BDC * ICGLCLK is the alternate BDC clock source for the MC9S08AW60/48/32/16. ADC1 RAM ADC has min and max frequency requirements. See Chapter 14, “Analog-to-Digital Converter (S08ADC10V1) and Appendix A, “Electrical Characteristics and Timing Specifications FLASH FLASH has frequency requirements for program and erase operation. See Appendix A, “Electrical Characteristics and Timing Specifications. Figure 1-2. System Clock Distribution Diagram MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 21 Chapter 1 Introduction Some of the modules inside the MCU have clock source choices. Figure 1-2 shows a simplified clock connection diagram. The ICG supplies the clock sources: • ICGOUT is an output of the ICG module. It is one of the following: — The external crystal oscillator — An external clock source — The output of the digitally-controlled oscillator (DCO) in the frequency-locked loop sub-module — Control bits inside the ICG determine which source is connected. • FFE is a control signal generated inside the ICG. If the frequency of ICGOUT > 4 × the frequency of ICGERCLK, this signal is a logic 1 and the fixed-frequency clock will be ICGERCLK/2. Otherwise the fixed-frequency clock will be BUSCLK. • ICGLCLK — Development tools can select this internal self-clocked source (~ 8 MHz) to speed up BDC communications in systems where the bus clock is slow. • ICGERCLK — External reference clock can be selected as the real-time interrupt clock source. Can also be used as the ALTCLK input to the ADC module. MC9S08AW60 Data Sheet, Rev.1.0 22 Freescale Semiconductor Chapter 2 Pins and Connections 2.1 Introduction This chapter describes signals that connect to package pins. It includes a pinout diagram, a table of signal properties, and detailed discussion of signals. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 23 Chapter 2 Pins and Connections PTC2/MCLK PTC1/SDA1 PTC0/SCL1 VSS PTG6/EXTAL PTG5/XTAL BKGD/MS VREFL VREFH PTD7/KBI1P7/AD1P15 PTD6/TPM1CLK/AD1P14 PTD5/AD1P13 PTD4/TPM2CLK/AD1P12 63 62 61 60 59 58 57 56 55 54 53 52 51 50 64 PTC4 1 PTG4/KBI1P4 PTC3/TxD2 Device Pin Assignment PTC5/RxD2 2.2 49 48 PTG3/KBI1P3 IRQ 2 47 PTD3/KBI1P6/AD1P11 RESET 3 46 PTD2/KBI1P5/AD1P10 PTF0/TPM1CH2 4 45 VSSAD PTF1/TPM1CH3 5 44 VDDAD PTF2/TPM1CH4 6 43 PTD1/AD1P9 PTF3/TPM1CH5 7 42 PTD0/AD1P8 PTF4/TPM2CH0 8 41 PTB7/AD1P7 PTC6 9 40 PTB6/AD1P6 PTF7 10 39 PTB5/AD1P5 PTF5/TPM2CH1 11 38 PTB4/AD1P4 PTF6 12 37 PTB3/AD1P3 PTE0/TxD1 13 36 PTB2/AD1P2 PTE1/RxD1 14 35 PTB1/AD1P1 PTE2/TPM1CH0 15 34 PTB0/AD1P0 64-Pin QFP 64-Pin LQFP PTE3/TPM1CH1 16 33 PTA7 18 19 20 21 22 23 24 25 26 27 28 29 30 31 PTA5 PTA4 PTA3 PTA2 PTA1 PTA0 PTG2/KBI1P2 PTG1/KBI1P1 PTG0/KBI1P0 VDD VSS PTE7/SPSCK1 PTE6/MOSI1 PTE5/MISO1 PTE4/SS1 PTA6 32 17 Figure 2-1. MC9S08AW60/48/32/16 in 64-Pin QFP/LQFP Package MC9S08AW60 Data Sheet, Rev.1.0 24 Freescale Semiconductor VREFH PTG4/KB1IP4 38 37 39 VREFL 40 BKGD/MS 41 PTG5/XTAL 42 PTG6/EXTAL 43 VSS 44 PTC0/SCL1 45 PTC1/SDA1 46 PTC2/MCLK 47 PTC3/TxD2 48 PTC5/RxD2 Chapter 2 Pins and Connections PTC4 1 36 PTG3/KBI1P3 IRQ 2 35 PTD3/KBI1P6/AD1P11 RESET 3 34 PTD2/KBI1P5/AD1P10 PTF0/TPM1CH2 4 33 VSSAD PTF1/TPM1CH3 5 32 VDDAD PTF4/TPM2CH0 6 31 PTD1/AD1P9 48-Pin QFN PTA2 24 25 PTA7 PTA1 23 PTE3/TPM1CH1 12 PTA0 22 26 PTB0/AD1P0 PTG2/KBI1P2 21 PTE2/TPM1CH0 11 PTG1/KBI1P1 20 27 PTB1/AD1P1 PTG0/KBI1P0 19 PTE1/RxD1 10 VDD 18 28 PTB2/AD1P2 VSS 17 PTE0/TxD1 9 PTE7/SPSCK1 16 29 PTB3/AD1P3 PTE6/MOSI1 15 PTF6 8 PTE5/MISO1 14 30 PTD0/AD1P8 PTE4/SS1 13 PTF5/TPM2CH1 7 Figure 2-2. MC9S08AW60/48/32/16 in 48-Pin QFN Package MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 25 34 44 43 PTC4 1 VREFH VREFL BKGD/MS PTG5/XTAL PTG6/EXTAL VSS PTC0/SCL1 PTC1/SDA1 PTC2/MCLK PTC3/TxD2 PTC5/RxD2 Chapter 2 Pins and Connections 42 41 40 39 38 37 36 35 33 PTG3/KBI1P3 IRQ 2 32 PTD3/KBI1P6/AD1P11 RESET 3 31 PTD2/KBI1P5/AD1P10 PTF0/TPM1CH2 4 30 VSSAD PTF1/TPM1CH3 5 29 VDDAD 28 PTD1/AD1P9 44-Pin LQFP PTF4/TPM2CH0 6 PTF5/TPM2CH1 7 27 PTD0/AD1P8 PTE0/TxD1 8 26 PTB3/AD1P3 PTE1/RxD1 9 25 PTB2/AD1P2 PTE2/TPM1CH0 10 24 PTB1/AD1P1 PTE3/TPM1CH1 11 23 PTB0/AD1P0 14 13 15 16 17 18 19 20 21 PTA0 PTG2/KBI1P2 PTG1/KBI1P1 PTG0/KBI1P0 VDD VSS PTE7/SPSCK1 PTE6/MOSI1 PTE5/MISO1 PTE4/SS1 PTA1 22 12 Figure 2-3. MC9S08AW60/48/32/16 in 44-Pin LQFP Package 2.3 Recommended System Connections Figure 2-4 shows pin connections that are common to almost all MC9S08AW60/48/32/16 application systems. MC9S08AW60 Data Sheet, Rev.1.0 26 Freescale Semiconductor Chapter 2 Pins and Connections VREFH CBYAD 0.1 µF PTA0 VSSAD VREFL VDD VDD SYSTEM POWER + CBLK + 10 µF 5V MC9S08AW60 VDDAD CBY 0.1 µF PTA1 PTA2 PORT A PTA3 PTA4 PTA5 VSS (x2) PTA6 PTA7 NOTE 1 RF C1 PTB0/AD1P0 RS XTAL NOTE 2 C2 X1 EXTAL NOTE 2 PTB1/AD1P1 PTB2/AD1P2 PORT B 1 BKGD/MS VDD 4.7 kΩ–10 kΩ PORT C INTERRUPT INPUT 0.1 µF I/O AND PTB7/AD1P7 PERIPHERAL PTC0/SCL1 INTERFACE TO PTC1/SDA1 APPLICATION PTC3/TxD2 SYSTEM PTC4 PTC5/RxD2 4.7 kΩ– 10 kΩ ASYNCHRONOUS PTB6/AD1P6 PTC2/MCLK RESET NOTE 3 0.1 µF VDD OPTIONAL MANUAL RESET PTB4/AD1P4 PTB5/AD1P5 BACKGROUND HEADER VDD PTB3/AD1P3 PTC6 IRQ NOTE 3 PTD0/AD1P8 PTD1/AD1P9 PTG0/KBI1P0 PTD2/AD1P10/KBI1P5 PTG1/KBI1P1 PTG2/KBI1P2 PTG3/KBI1P3 NOTES: 1. Not required if using the internal clock option. 2. These are the same pins as PTG5 and PTG6 3. RC filters on RESET and IRQ are recommended for EMC-sensitive applications. PORT G PORT D PTD3/AD1P11/KBI1P6 PTD4/AD1P12/TPM2CLK PTG4/KBI1P4 PTG5/XTAL PTD5/AD1P13 PTG6/EXTAL PTD7/AD1P15/KBI1P7 PTD6/AD1P14/TPM1CLK PTF0/TPM1CH2 PTE0/TxD1 PTF1/TPM1CH3 PTE1/RxD1 PTE2/TPM1CH0 PTF2/TPM1CH4 PTF3/TPM1CH5 PTF4/TPM2CH0 PORT F PORT E PTF5/TPM2CH1 PTF6 PTF7 PTE3/TPM1CH1 PTE4/SS1 PTE5/MISO1 PTE6/MOSI1 PTE7/SPSCK1 Figure 2-4. Basic System Connections MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 27 Chapter 2 Pins and Connections 2.3.1 Power (VDD, 2 x VSS, VDDAD, VSSAD) VDD and VSS are the primary power supply pins for the MCU. This voltage source supplies power to all I/O buffer circuitry and to an internal voltage regulator. The internal voltage regulator provides regulated lower-voltage source to the CPU and other internal circuitry of the MCU. Typically, application systems have two separate capacitors across the power pins. In this case, there should be a bulk electrolytic capacitor, such as a 10-µF tantalum capacitor, to provide bulk charge storage for the overall system and a 0.1-µF ceramic bypass capacitor located as near to the paired VDD and VSS power pins as practical to suppress high-frequency noise. The MC9S08AW60 has a second VSS pin. This pin should be connected to the system ground plane or to the primary VSS pin through a low-impedance connection. VDDAD and VSSAD are the analog power supply pins for the MCU. This voltage source supplies power to the ADC module. A 0.1-µF ceramic bypass capacitor should be located as near to the analog power pins as practical to suppress high-frequency noise. 2.3.2 Oscillator (XTAL, EXTAL) Out of reset the MCU uses an internally generated clock (self-clocked mode — fSelf_reset) equivalent to about 8-MHz crystal rate. This frequency source is used during reset startup and can be enabled as the clock source for stop recovery to avoid the need for a long crystal startup delay. This MCU also contains a trimmable internal clock generator (ICG) module that can be used to run the MCU. For more information on the ICG, see the Chapter 8, “Internal Clock Generator (S08ICGV4).” The oscillator in this MCU is a Pierce oscillator that can accommodate a crystal or ceramic resonator in either of two frequency ranges selected by the RANGE bit in the ICGC1 register. Rather than a crystal or ceramic resonator, an external oscillator can be connected to the EXTAL input pin. Refer to Figure 2-4 for the following discussion. RS (when used) and RF should be low-inductance resistors such as carbon composition resistors. Wire-wound resistors, and some metal film resistors, have too much inductance. C1 and C2 normally should be high-quality ceramic capacitors that are specifically designed for high-frequency applications. RF is used to provide a bias path to keep the EXTAL input in its linear range during crystal startup and its value is not generally critical. Typical systems use 1 MΩ to 10 MΩ. Higher values are sensitive to humidity and lower values reduce gain and (in extreme cases) could prevent startup. C1 and C2 are typically in the 5-pF to 25-pF range and are chosen to match the requirements of a specific crystal or resonator. Be sure to take into account printed circuit board (PCB) capacitance and MCU pin capacitance when sizing C1 and C2. The crystal manufacturer typically specifies a load capacitance which is the series combination of C1 and C2 which are usually the same size. As a first-order approximation, use 10 pF as an estimate of combined pin and PCB capacitance for each oscillator pin (EXTAL and XTAL). 2.3.3 RESET RESET is a dedicated pin with a pullup device built in. It has input hysteresis, a high current output driver, and no output slew rate control. Internal power-on reset and low-voltage reset circuitry typically make MC9S08AW60 Data Sheet, Rev.1.0 28 Freescale Semiconductor Chapter 2 Pins and Connections external reset circuitry unnecessary. This pin is normally connected to the standard 6-pin background debug connector so a development system can directly reset the MCU system. If desired, a manual external reset can be added by supplying a simple switch to ground (pull reset pin low to force a reset). Whenever any reset is initiated (whether from an external signal or from an internal system), the reset pin is driven low for approximately 34 bus cycles, released, and sampled again approximately 38 bus cycles later. If reset was caused by an internal source such as low-voltage reset or watchdog timeout, the circuitry expects the reset pin sample to return a logic 1. The reset circuitry decodes the cause of reset and records it by setting a corresponding bit in the system control reset status register (SRS). In EMC-sensitive applications, an external RC filter is recommended on the reset pin. See Figure 2-4 for an example. 2.3.4 Background/Mode Select (BKGD/MS) While in reset, the BKGD/MS pin functions as a mode select pin. Immediately after reset rises the pin functions as the background pin and can be used for background debug communication. While functioning as a background/mode select pin, the pin includes an internal pullup device, input hysteresis, a standard output driver, and no output slew rate control. If nothing is connected to this pin, the MCU will enter normal operating mode at the rising edge of reset. If a debug system is connected to the 6-pin standard background debug header, it can hold BKGD/MS low during the rising edge of reset which forces the MCU to active background mode. The BKGD pin is used primarily for background debug controller (BDC) communications using a custom protocol that uses 16 clock cycles of the target MCU’s BDC clock per bit time. The target MCU’s BDC clock could be as fast as the bus clock rate, so there should never be any significant capacitance connected to the BKGD/MS pin that could interfere with background serial communications. Although the BKGD pin is a pseudo open-drain pin, the background debug communication protocol provides brief, actively driven, high speedup pulses to ensure fast rise times. Small capacitances from cables and the absolute value of the internal pullup device play almost no role in determining rise and fall times on the BKGD pin. 2.3.5 ADC Reference Pins (VREFH, VREFL) The VREFH and VREFL pins are the voltage reference high and voltage reference low inputs respectively for the ADC module. 2.3.6 External Interrupt Pin (IRQ) The IRQ pin is the input source for the IRQ interrupt and is also the input for the BIH and BIL instructions. If the IRQ function is not enabled, this pin does not perform any function. When IRQ is configured as the IRQ input and is set to detect rising edges, a pulldown device rather than a pullup device is enabled. In EMC-sensitive applications, an external RC filter is recommended on the IRQ pin. See Figure 2-4 for an example. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 29 Chapter 2 Pins and Connections 2.3.7 General-Purpose I/O and Peripheral Ports The remaining pins are shared among general-purpose I/O and on-chip peripheral functions such as timers and serial I/O systems. Immediately after reset, all of these pins are configured as high-impedance general-purpose inputs with internal pullup devices disabled. NOTE To avoid extra current drain from floating input pins, the reset initialization routine in the application program should either enable on-chip pullup devices or change the direction of unused pins to outputs so the pins do not float. For information about controlling these pins as general-purpose I/O pins, see Chapter 6, “Parallel Input/Output.” For information about how and when on-chip peripheral systems use these pins, refer to the appropriate chapter from Table 2-1. Table 2-1. Pin Sharing Priority Lowest <- Pin Function Priority -> Highest Port Pins PTB7–PTB0 1 Alternate Function Reference1 Alternate Function AD1P7–AD1P0 Chapter 14, “Analog-to-Digital Converter (S08ADC10V1)” PTC5, PTC3 RxD2–TxD2 Chapter 11, “Serial Communications Interface (S08SCIV2)” PTC2 MCLK Chapter 5, “Resets, Interrupts, and System Configuration” PTC1–PTC0 SCL1–SDA1 PTD7 KBI1P7 AD1P15 Chapter 13, “Inter-Integrated Circuit (S08IICV1)” Chapter 14, “Analog-to-Digital Converter (S08ADC10V1)” Chapter 9, “Keyboard Interrupt (S08KBIV1)” PTD6 TPM1CLK AD1P14 Chapter 14, “Analog-to-Digital Converter (S08ADC10V1)” Chapter 10, “Timer/PWM (S08TPMV2)” PTD5 AD1P13 AD1P13 Chapter 14, “Analog-to-Digital Converter (S08ADC10V1)” PTD4 TPM2CLK AD1P12 Chapter 14, “Analog-to-Digital Converter (S08ADC10V1)” Chapter 10, “Timer/PWM (S08TPMV2)” PTD3–PTD2 KBI1P6–KBI1P5 AD1P11–AD1P10 Chapter 14, “Analog-to-Digital Converter (S08ADC10V1)” Chapter 9, “Keyboard Interrupt (S08KBIV1)” PTD1–PTD0 AD1P9–AD1P8 Chapter 14, “Analog-to-Digital Converter (S08ADC10V1)” PTE7 PTE6 PTE5 PTE4 SPSCK1 MOSI1 MISO1 SS1 Chapter 12, “Serial Peripheral Interface (S08SPIV3)” PTE3–PTE2 TPM1CH1– TPM1CH0 Chapter 10, “Timer/PWM (S08TPMV2)” PTE1–PTE0 RxD1–TxD1 Chapter 11, “Serial Communications Interface (S08SCIV2)” PTF5–PTF4 TPM2CH1– TPM2CH0 Chapter 10, “Timer/PWM (S08TPMV2)” PTF3–PTF0 TPM1CH5– TPM1CH2 Chapter 10, “Timer/PWM (S08TPMV2)” PTG4–PTG0 KBI1P4–KBI1P0 Chapter 9, “Keyboard Interrupt (S08KBIV1)” PTG6–PTG5 EXTAL–XTAL Chapter 8, “Internal Clock Generator (S08ICGV4)” See the listed chapter for information about modules that share these pins. MC9S08AW60 Data Sheet, Rev.1.0 30 Freescale Semiconductor Chapter 2 Pins and Connections When an on-chip peripheral system is controlling a pin, data direction control bits still determine what is read from port data registers even though the peripheral module controls the pin direction by controlling the enable for the pin’s output buffer. See the Chapter 6, “Parallel Input/Output” chapter for more details. Pullup enable bits for each input pin control whether on-chip pullup devices are enabled whenever the pin is acting as an input even if it is being controlled by an on-chip peripheral module. When the PTD7, PTD3, PTD2, and PTG4 pins are controlled by the KBI module and are configured for rising-edge/high-level sensitivity, the pullup enable control bits enable pulldown devices rather than pullup devices. NOTE When an alternative function is first enabled it is possible to get a spurious edge to the module, user software should clear out any associated flags before interrupts are enabled. Table 2-1 illustrates the priority if multiple modules are enabled. The highest priority module will have control over the pin. Selecting a higher priority pin function with a lower priority function already enabled can cause spurious edges to the lower priority module. It is recommended that all modules that share a pin be disabled before enabling another module. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 31 Chapter 2 Pins and Connections MC9S08AW60 Data Sheet, Rev.1.0 32 Freescale Semiconductor Chapter 3 Modes of Operation 3.1 Introduction The operating modes of the MC9S08AW60/48/32/16 are described in this chapter. Entry into each mode, exit from each mode, and functionality while in each of the modes are described. 3.2 • • • 3.3 Features Active background mode for code development Wait mode: — CPU shuts down to conserve power — System clocks running — Full voltage regulation maintained Stop modes: — System clocks stopped; voltage regulator in standby — Stop2 — Partial power down of internal circuits, RAM contents retained — Stop3 — All internal circuits powered for fast recovery Run Mode This is the normal operating mode for the MC9S08AW60/48/32/16. This mode is selected when the BKGD/MS pin is high at the rising edge of reset. In this mode, the CPU executes code from internal memory with execution beginning at the address fetched from memory at $FFFE:$FFFF after reset. 3.4 Active Background Mode The active background mode functions are managed through the background debug controller (BDC) in the HCS08 core. The BDC, together with the on-chip debug module (DBG), provide the means for analyzing MCU operation during software development. Active background mode is entered in any of five ways: • When the BKGD/MS pin is low at the rising edge of reset • When a BACKGROUND command is received through the BKGD pin • When a BGND instruction is executed • When encountering a BDC breakpoint • When encountering a DBG breakpoint MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 33 Chapter 3 Modes of Operation After entering active background mode, the CPU is held in a suspended state waiting for serial background commands rather than executing instructions from the user’s application program. Background commands are of two types: • Non-intrusive commands, defined as commands that can be issued while the user program is running. Non-intrusive commands can be issued through the BKGD pin while the MCU is in run mode; non-intrusive commands can also be executed when the MCU is in the active background mode. Non-intrusive commands include: — Memory access commands — Memory-access-with-status commands — BDC register access commands — The BACKGROUND command • Active background commands, which can only be executed while the MCU is in active background mode. Active background commands include commands to: — Read or write CPU registers — Trace one user program instruction at a time — Leave active background mode to return to the user’s application program (GO) The active background mode is used to program a bootloader or user application program into the FLASH program memory before the MCU is operated in run mode for the first time. When the MC9S08AW60/48/32/16 is shipped from the Freescale Semiconductor factory, the FLASH program memory is erased by default unless specifically noted so there is no program that could be executed in run mode until the FLASH memory is initially programmed. The active background mode can also be used to erase and reprogram the FLASH memory after it has been previously programmed. For additional information about the active background mode, refer to Chapter 15, “Development Support.” 3.5 Wait Mode Wait mode is entered by executing a WAIT instruction. Upon execution of the WAIT instruction, the CPU enters a low-power state in which it is not clocked. The I bit in CCR is cleared when the CPU enters the wait mode, enabling interrupts. When an interrupt request occurs, the CPU exits the wait mode and resumes processing, beginning with the stacking operations leading to the interrupt service routine. While the MCU is in wait mode, there are some restrictions on which background debug commands can be used. Only the BACKGROUND command and memory-access-with-status commands are available when the MCU is in wait mode. The memory-access-with-status commands do not allow memory access, but they report an error indicating that the MCU is in either stop or wait mode. The BACKGROUND command can be used to wake the MCU from wait mode and enter active background mode. 3.6 Stop Modes One of two stop modes is entered upon execution of a STOP instruction when the STOPE bit in the system option register is set. In both stop modes, all internal clocks are halted. If the STOPE bit is not set when MC9S08AW60 Data Sheet, Rev.1.0 34 Freescale Semiconductor Chapter 3 Modes of Operation the CPU executes a STOP instruction, the MCU will not enter either of the stop modes and an illegal opcode reset is forced. The stop modes are selected by setting the appropriate bits in SPMSC2. HCS08 devices that are designed for low voltage operation (1.8V to 3.6V) also include stop1 mode. The MC9S08AW60/48/32/16 family of devices does not include stop1 mode. Table 3-1 summarizes the behavior of the MCU in each of the stop modes. Table 3-1. Stop Mode Behavior 1 Mode PPDC CPU, Digital Peripherals, FLASH RAM ICG ADC1 Regulator I/O Pins RTI Stop2 1 Off Standby Off Disabled Standby States held Optionally on Stop3 0 Standby Standby Off1 Optionally on Standby States held Optionally on Crystal oscillator can be configured to run in stop3. Please see the ICG registers. 3.6.1 Stop2 Mode The stop2 mode provides very low standby power consumption and maintains the contents of RAM and the current state of all of the I/O pins. To enter stop2, the user must execute a STOP instruction with stop2 selected (PPDC = 1) and stop mode enabled (STOPE = 1). In addition, the LVD must not be enabled to operate in stop (LVDSE = 0 or LVDE = 0). If the LVD is enabled in stop, then the MCU enters stop3 upon the execution of the STOP instruction regardless of the state of PPDC. Before entering stop2 mode, the user must save the contents of the I/O port registers, as well as any other memory-mapped registers which they want to restore after exit of stop2, to locations in RAM. Upon exit of stop2, these values can be restored by user software before pin latches are opened. When the MCU is in stop2 mode, all internal circuits that are powered from the voltage regulator are turned off, except for the RAM. The voltage regulator is in a low-power standby state, as is the ADC. Upon entry into stop2, the states of the I/O pins are latched. The states are held while in stop2 mode and after exiting stop2 mode until a logic 1 is written to PPDACK in SPMSC2. Exit from stop2 is done by asserting either of the wake-up pins: RESET or IRQ, or by an RTI interrupt. IRQ is always an active low input when the MCU is in stop2, regardless of how it was configured before entering stop2. NOTE Although this IRQ pin is automatically configured as active low input, the pullup associated with the IRQ pin is not automatically enabled. Therefore, if an external pullup is not used, the internal pullup must be enabled by setting IRQPE in IRQSC. Upon wake-up from stop2 mode, the MCU will start up as from a power-on reset (POR) except pin states remain latched. The CPU will take the reset vector. The system and all peripherals will be in their default reset states and must be initialized. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 35 Chapter 3 Modes of Operation After waking up from stop2, the PPDF bit in SPMSC2 is set. This flag may be used to direct user code to go to a stop2 recovery routine. PPDF remains set and the I/O pin states remain latched until a logic 1 is written to PPDACK in SPMSC2. To maintain I/O state for pins that were configured as general-purpose I/O, the user must restore the contents of the I/O port registers, which have been saved in RAM, to the port registers before writing to the PPDACK bit. If the port registers are not restored from RAM before writing to PPDACK, then the register bits will assume their reset states when the I/O pin latches are opened and the I/O pins will switch to their reset states. For pins that were configured as peripheral I/O, the user must reconfigure the peripheral module that interfaces to the pin before writing to the PPDACK bit. If the peripheral module is not enabled before writing to PPDACK, the pins will be controlled by their associated port control registers when the I/O latches are opened. 3.6.2 Stop3 Mode Stop3 mode is entered by executing a STOP instruction under the conditions as shown in Table 3-1. The states of all of the internal registers and logic, RAM contents, and I/O pin states are maintained. Stop3 can be exited by asserting RESET, or by an interrupt from one of the following sources: the real-time interrupt (RTI), LVD, ADC, IRQ, or the KBI. If stop3 is exited by means of the RESET pin, then the MCU is reset and operation will resume after taking the reset vector. Exit by means of one of the internal interrupt sources results in the MCU taking the appropriate interrupt vector. 3.6.3 Active BDM Enabled in Stop Mode Entry into the active background mode from run mode is enabled if the ENBDM bit in BDCSCR is set. This register is described in Chapter 15, “Development Support” of this data sheet. If ENBDM is set when the CPU executes a STOP instruction, the system clocks to the background debug logic remain active when the MCU enters stop mode so background debug communication is still possible. In addition, the voltage regulator does not enter its low-power standby state but maintains full internal regulation. If the user attempts to enter stop2 with ENBDM set, the MCU will instead enter stop3. Most background commands are not available in stop mode. The memory-access-with-status commands do not allow memory access, but they report an error indicating that the MCU is in either stop or wait mode. The BACKGROUND command can be used to wake the MCU from stop and enter active background mode if the ENBDM bit is set. After entering background debug mode, all background commands are available. Table 3-2 summarizes the behavior of the MCU in stop when entry into the background debug mode is enabled. MC9S08AW60 Data Sheet, Rev.1.0 36 Freescale Semiconductor Chapter 3 Modes of Operation Table 3-2. BDM Enabled Stop Mode Behavior Mode PPDC CPU, Digital Peripherals, FLASH RAM ICG ADC1 Regulator I/O Pins RTI Stop3 0 Standby Standby Active Optionally on Active States held Optionally on 3.6.4 LVD Enabled in Stop Mode The LVD system is capable of generating either an interrupt or a reset when the supply voltage drops below the LVD voltage. If the LVD is enabled in stop by setting the LVDE and the LVDSE bits, then the voltage regulator remains active during stop mode. If the user attempts to enter stop2 with the LVD enabled for stop, the MCU will instead enter stop3. Table 3-3 summarizes the behavior of the MCU in stop when the LVD is enabled. Table 3-3. LVD Enabled Stop Mode Behavior 1 Mode PPDC CPU, Digital Peripherals, FLASH RAM ICG ADC1 Regulator I/O Pins RTI Stop3 0 Standby Standby Off1 Optionally on Active States held Optionally on Crystal oscillator can be configured to run in stop3. Please see the ICG registers. 3.6.5 On-Chip Peripheral Modules in Stop Modes When the MCU enters any stop mode, system clocks to the internal peripheral modules are stopped. Even in the exception case (ENBDM = 1), where clocks to the background debug logic continue to operate, clocks to the peripheral systems are halted to reduce power consumption. Refer to Section 3.6.1, “Stop2 Mode,” and Section 3.6.2, “Stop3 Mode,” for specific information on system behavior in stop modes. Table 3-4. Stop Mode Behavior Mode Peripheral Stop2 Stop3 CPU Off Standby RAM Standby Standby FLASH Off Standby Parallel Port Registers Off Standby ADC1 Off Optionally On1 ICG Off Optionally On2 IIC Off Standby MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 37 Chapter 3 Modes of Operation Table 3-4. Stop Mode Behavior (continued) Mode Peripheral Stop2 Stop3 KBI Off Optionally On3 RTI Optionally On4 Optionally On4 SCI Off Standby SPI Off Standby TPM Off Standby Standby Standby States Held States Held Voltage Regulator I/O Pins 1 Requires the asynchronous ADC clock and LVD to be enabled, else in standby. 2 OSCSTEN set in ICSC1, else in standby. For high frequency range (RANGE in ICSC2 set) requires the LVD to also be enabled in stop3. 3 During stop3, KBI pins that are enabled continue to function as interrupt sources that are capable of waking the MCU from stop3. 4 This RTI can be enabled to run in stop2 or stop3 with the internal RTI clock source (RTICLKS = 0, in SRTISC). The RTI also can be enabled to run in stop3 with the external clock source (RTICLKS = 1 and OSCSTEN = 1). MC9S08AW60 Data Sheet, Rev.1.0 38 Freescale Semiconductor Chapter 4 Memory 4.1 MC9S08AW60/48/32/16 Memory Map Figure 4-1 shows the memory map for the MC9S08AW60 and MC9S08AW48 MCUs. Figure 4-2 shows the memory map for the MC9S08AW32 and MC9S08AW16 MCUs. On-chip memory in the MC9S08AW60/48/32/16 series of MCUs consists of RAM, FLASH program memory for nonvolatile data storage, plus I/O and control/status registers. The registers are divided into three groups: • Direct-page registers ($0000 through $006F) • High-page registers ($1800 through $185F) • Nonvolatile registers ($FFB0 through $FFBF) MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 39 Chapter 4 Memory $0000 $006F $0070 DIRECT PAGE REGISTERS $0000 RAM 2048 BYTES $086F $0870 $17FF $1800 DIRECT PAGE REGISTERS $006F $0070 FLASH RAM 2048 BYTES $086F $0870 3984 BYTES RESERVED 3984 BYTES $17FF $1800 HIGH PAGE REGISTERS $185F $1860 HIGH PAGE REGISTERS $185F $1860 RESERVED 10,144 BYTES $3FFF $4000 FLASH 59,296 BYTES FLASH 49,152 BYTES $FFFF $FFFF MC9S08AW60 MC9S08AW48 Figure 4-1. MC9S08AW60 and MC9S08AW48 Memory Map MC9S08AW60 Data Sheet, Rev.1.0 40 Freescale Semiconductor Chapter 4 Memory $0000 $006F $0070 DIRECT PAGE REGISTERS DIRECT PAGE REGISTERS $006F $0070 RAM RAM 1024 BYTES $046F $0470 2048 BYTES $086F $0870 $0000 RESERVED RESERVED 5008 BYTES 3984 BYTES $17FF $1800 $17FF $1800 HIGH PAGE REGISTERS HIGH PAGE REGISTERS $185F $1860 $185F $1860 RESERVED RESERVED 26,528 BYTES 42,912 BYTES $7FFF $8000 $BFFF $C000 FLASH FLASH 32,768 BYTES 16,384 BYTES $FFFF $FFFF MC9S08AW32 MC9S08AW16 Figure 4-2. MC9S08AW32 and MC9S08AW16 Memory Map MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 41 Chapter 4 Memory 4.1.1 Reset and Interrupt Vector Assignments Figure 4-1 shows address assignments for reset and interrupt vectors. The vector names shown in this table are the labels used in the Freescale-provided equate file for the MC9S08AW60/48/32/16. For more details about resets, interrupts, interrupt priority, and local interrupt mask controls, refer to Chapter 5, “Resets, Interrupts, and System Configuration.” Table 4-1. Reset and Interrupt Vectors Address (High/Low) $FFC0:FFC1 Vector Vector Name Unused Vector Space (available for user program) $FFCA:FFCB $FFCC:FFCD RTI Vrti $FFCE:FFCF IIC1 Viic1 $FFD0:FFD1 ADC1 Conversion Vadc1 $FFD2:FFD3 KBI1 Vkeyboard1 $FFD4:FFD5 SCI2 Transmit Vsci2tx $FFD6:FFD7 SCI2 Receive Vsci2rx $FFD8:FFD9 SCI2 Error Vsci2err $FFDA:FFDB SCI1 Transmit Vsci1tx $FFDC:FFDD SCI1 Receive Vsci1rx $FFDE:FFDF SCI1 Error Vsci1err $FFE0:FFE1 SPI1 Vspi1 $FFE2:FFE3 TPM2 Overflow Vtpm2ovf $FFE4:FFE5 TPM2 Channel 1 Vtpm2ch1 $FFE6:FFE7 TPM2 Channel 0 Vtpm2ch0 $FFE8:FFE9 TPM1 Overflow Vtpm1ovf $FFEA:FFEB TPM1 Channel 5 Vtpm1ch5 $FFEC:FFED TPM1 Channel 4 Vtpm1ch4 $FFEE:FFEF TPM1 Channel 3 Vtpm1ch3 $FFF0:FFF1 TPM1 Channel 2 Vtpm1ch2 $FFF2:FFF3 TPM1 Channel 1 Vtpm1ch1 $FFF4:FFF5 TPM1 Channel 0 Vtpm1ch0 $FFF6:FFF7 ICG Vicg $FFF8:FFF9 Low Voltage Detect Vlvd $FFFA:FFFB IRQ Virq $FFFC:FFFD SWI Vswi $FFFE:FFFF Reset Vreset MC9S08AW60 Data Sheet, Rev.1.0 42 Freescale Semiconductor Chapter 4 Memory 4.2 Register Addresses and Bit Assignments The registers in the MC9S08AW60/48/32/16 are divided into these three groups: • Direct-page registers are located in the first 112 locations in the memory map, so they are accessible with efficient direct addressing mode instructions. • High-page registers are used much less often, so they are located above $1800 in the memory map. This leaves more room in the direct page for more frequently used registers and variables. • The nonvolatile register area consists of a block of 16 locations in FLASH memory at $FFB0–$FFBF. Nonvolatile register locations include: — Three values which are loaded into working registers at reset — An 8-byte backdoor comparison key which optionally allows a user to gain controlled access to secure memory Because the nonvolatile register locations are FLASH memory, they must be erased and programmed like other FLASH memory locations. Direct-page registers can be accessed with efficient direct addressing mode instructions. Bit manipulation instructions can be used to access any bit in any direct-page register. Table 4-2 is a summary of all user-accessible direct-page registers and control bits. The direct page registers in Table 4-2 can use the more efficient direct addressing mode which only requires the lower byte of the address. Because of this, the lower byte of the address in column one is shown in bold text. In Table 4-3 and Table 4-4 the whole address in column one is shown in bold. In Table 4-2, Table 4-3, and Table 4-4, the register names in column two are shown in bold to set them apart from the bit names to the right. Cells that are not associated with named bits are shaded. A shaded cell with a 0 indicates this unused bit always reads as a 0. Shaded cells with dashes indicate unused or reserved bit locations that could read as 1s or 0s. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 43 Chapter 4 Memory Table 4-2. Direct-Page Register Summary (Sheet 1 of 3) Address Register Name $0000 $0001 $0002 $0003 $0004 $0005 $0006 $0007 $0008 $0009 $000A $000B PTAD PTADD PTBD PTBDD PTCD PTCDD PTDD PTDDD PTED PTEDD PTFD PTFDD $000C $000D $000E– $000F $0010 $0011 $0012 $0013 $0014 $0015 $0016 $0017 $0018 $0019 $001A– $001B $001C $001D $001E $001F $0020 $0021 $0022 $0023 $0024 $0025 $0026 $0027 PTGD PTGDD Reserved ADC1SC1 ADC1SC2 ADC1RH ADC1RL ADC1CVH ADC1CVL ADC1CFG APCTL1 APCTL2 APCTL3 Reserved IRQSC Reserved KBISC KBIPE TPM1SC TPM1CNTH TPM1CNTL TPM1MODH TPM1MODL TPM1C0SC TPM1C0VH TPM1C0VL Bit 7 6 5 4 3 2 1 Bit 0 PTAD7 PTAD6 PTAD5 PTAD4 PTAD3 PTAD2 PTAD1 PTAD0 PTADD7 PTADD6 PTADD5 PTADD4 PTADD3 PTADD2 PTADD1 PTADD0 PTBD7 PTBD6 PTBD5 PTBD4 PTBD3 PTBD2 PTBD1 PTBD0 PTBDD7 PTBDD6 PTBDD5 PTBDD4 PTBDD3 PTBDD2 PTBDD1 PTBDD0 0 PTCD6 PTCD5 PTCD4 PTCD3 PTCD2 PTCD1 PTCD0 0 PTCDD6 PTCDD5 PTCDD4 PTCDD3 PTCDD2 PTCDD1 PTCDD0 PTDD7 PTDD6 PTDD5 PTDD4 PTDD3 PTDD2 PTDD1 PTDD0 PTDDD7 PTDDD6 PTDDD5 PTDDD4 PTDDD3 PTDDD2 PTDDD1 PTDDD0 PTED7 PTED6 PTED5 PTED4 PTED3 PTED2 PTED1 PTED0 PTEDD7 PTEDD6 PTEDD5 PTEDD4 PTEDD3 PTEDD2 PTEDD1 PTEDD0 PTFD7 PTFD6 PTFD5 PTFD4 PTFD3 PTFD2 PTFD1 PTFD0 PTFDD7 PTFDD6 PTFDD5 PTFDD4 PTFDD3 PTFDD2 PTFDD1 PTFDD0 0 PTGD6 PTGD5 PTGD4 PTGD3 PTGD2 PTGD1 PTGD0 0 PTGDD6 PTGDD5 PTGDD4 PTGDD3 PTGDD2 PTGDD1 PTGDD0 — — — — — — — — — — — — — — — — COCO AIEN ADCO ADACT ADTRG ACFE ACFGT 0 0 R R 0 0 0 0 0 0 ADR9 ADR8 ADR7 ADR6 ADR5 ADR4 ADR3 ADR2 ADR1 ADR0 0 0 0 0 0 0 ADCV9 ADCV8 ADCV7 ADCV6 ADCV5 ADCV4 ADCV3 ADCV2 ADCV1 ADCV0 ADLPC ADIV ADCH ADLSMP MODE ADICLK ADPC7 ADPC6 ADPC5 ADPC4 ADPC3 ADPC2 ADPC1 ADPC0 ADPC15 ADPC14 ADPC13 ADPC12 ADPC11 ADPC10 ADPC9 ADPC8 ADPC23 ADPC22 ADPC21 ADPC20 ADPC19 ADPC18 ADPC17 ADPC16 — — — — — — — — — — — — — — — — 0 0 IRQEDG IRQPE IRQF IRQACK IRQIE IRQMOD — — — — — — — — KBEDG7 KBEDG6 KBEDG5 KBEDG4 KBF KBACK KBIE KBIMOD KBIPE7 KBIPE6 KBIPE5 KBIPE4 KBIPE3 KBIPE2 KBIPE1 KBIPE0 TOF TOIE CPWMS CLKSB CLKSA PS2 PS1 PS0 Bit 15 14 13 12 11 10 9 Bit 8 Bit 7 6 5 4 3 2 1 Bit 0 Bit 15 14 13 12 11 10 9 Bit 8 Bit 7 6 5 4 3 2 1 Bit 0 CH0F CH0IE MS0B MS0A ELS0B ELS0A 0 0 Bit 15 14 13 12 11 10 9 Bit 8 Bit 7 6 5 4 3 2 1 Bit 0 MC9S08AW60 Data Sheet, Rev.1.0 44 Freescale Semiconductor Chapter 4 Memory Table 4-2. Direct-Page Register Summary (Sheet 2 of 3) Address Register Name Bit 7 6 5 4 3 2 1 Bit 0 $0028 $0029 $002A $002B $002C $002D $002E $002F $0030 $0031 $0032 $0033 TPM1C1SC TPM1C1VH TPM1C1VL TPM1C2SC TPM1C2VH TPM1C2VL TPM1C3SC TPM1C3VH TPM1C3VL TPM1C4SC TPM1C4VH TPM1C4VL CH1F CH1IE MS1B MS1A ELS1B ELS1A 0 0 Bit 15 14 13 12 11 10 9 Bit 8 $0034 $0035 $0036 $0037 $0038 $0039 $003A $003B $003C $003D $003E $003F $0040 $0041 $0042 $0043 $0044 $0045 $0046 $0047 $0048 $0049 $004A $004B $004C $004D $004E $004F TPM1C5SC TPM1C5VH TPM1C5VL Reserved SCI1BDH SCI1BDL SCI1C1 SCI1C2 SCI1S1 SCI1S2 SCI1C3 SCI1D SCI2BDH SCI2BDL SCI2C1 SCI2C2 SCI2S1 SCI2S2 SCI2C3 SCI2D ICGC1 ICGC2 ICGS1 ICGS2 ICGFLTU ICGFLTL ICGTRM Reserved Bit 7 6 5 4 3 2 1 Bit 0 CH2F CH2IE MS2B MS2A ELS2B ELS2A 0 0 Bit 15 14 13 12 11 10 9 Bit 8 Bit 7 6 5 4 3 2 1 Bit 0 CH3F CH3IE MS3B MS3A ELS3B ELS3A 0 0 Bit 15 14 13 12 11 10 9 Bit 8 Bit 7 6 5 4 3 2 1 Bit 0 CH4F CH4IE MS4B MS4A ELS4B ELS4A 0 0 Bit 15 14 13 12 11 10 9 Bit 8 Bit 7 6 5 4 3 2 1 Bit 0 CH5F CH5IE MS5B MS5A ELS5B ELS5A 0 0 Bit 15 14 13 12 11 10 9 Bit 8 Bit 7 6 5 4 3 2 1 Bit 0 — — — — — — — — 0 0 0 SBR12 SBR11 SBR10 SBR9 SBR8 SBR7 SBR6 SBR5 SBR4 SBR3 SBR2 SBR1 SBR0 LOOPS SCISWAI RSRC M WAKE ILT PE PT TIE TCIE RIE ILIE TE RE RWU SBK TDRE TC RDRF IDLE OR NF FE PF 0 0 0 0 0 BRK13 0 RAF R8 T8 TXDIR TXINV ORIE NEIE FEIE PEIE Bit 7 6 5 4 3 2 1 Bit 0 0 0 0 SBR12 SBR11 SBR10 SBR9 SBR8 SBR7 SBR6 SBR5 SBR4 SBR3 SBR2 SBR1 SBR0 LOOPS SCISWAI RSRC M WAKE ILT PE PT TIE TCIE RIE ILIE TE RE RWU SBK TDRE TC RDRF IDLE OR NF FE PF 0 0 0 0 0 BRK13 0 RAF R8 T8 TXDIR TXINV ORIE NEIE FEIE PEIE Bit 7 6 5 4 3 2 1 Bit 0 HGO RANGE REFS OSCSTEN LOCD 0 LOLRE CLKS MFD CLKST LOCRE RFD REFST LOLS LOCK LOCS ERCS ICGIF 0 0 0 0 0 0 0 DCOS 0 0 0 0 — — FLT FLT TRIM — — — — — — MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 45 Chapter 4 Memory Table 4-2. Direct-Page Register Summary (Sheet 3 of 3) Address Register Name $0050 $0051 $0052 $0053 $0054 $0055 $0056– $0057 $0058 $0059 $005A $005B SPI1C1 SPI1C2 SPI1BR SPI1S Reserved SPI1D $005C $005D– $005F $0060 $0061 $0062 $0063 $0064 $0065 $0066 $0067 $0068 $0069 $006A $006B– $006F IIC1D Reserved IIC1A IIC1F IIC1C IIC1S Reserved TPM2SC TPM2CNTH TPM2CNTL TPM2MODH TPM2MODL TPM2C0SC TPM2C0VH TPM2C0VL TPM2C1SC TPM2C1VH TPM2C1VL Reserved Bit 7 6 5 4 3 2 1 Bit 0 SPIE SPE SPTIE MSTR CPOL CPHA SSOE LSBFE 0 0 0 MODFEN BIDIROE 0 SPISWAI SPC0 0 SPPR2 SPPR1 SPPR0 0 SPR2 SPR1 SPR0 SPRF 0 SPTEF MODF 0 0 0 0 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 Bit 0 — — — — — — — — — — — — — — — — ADDR 0 MULT ICR IICEN IICIE MST TX TCF IAAS BUSY ARBL TXAK RSTA 0 0 0 SRW IICIF RXAK DATA — — — — — — — — — — — — — — — — TOF TOIE CPWMS CLKSB CLKSA PS2 PS1 PS0 Bit 15 14 13 12 11 10 9 Bit 8 Bit 7 6 5 4 3 2 1 Bit 0 Bit 15 14 13 12 11 10 9 Bit 8 Bit 7 6 5 4 3 2 1 Bit 0 CH0F CH0IE MS0B MS0A ELS0B ELS0A 0 0 Bit 15 14 13 12 11 10 9 Bit 8 Bit 7 6 5 4 3 2 1 Bit 0 CH1F CH1IE MS1B MS1A ELS1B ELS1A 0 0 Bit 15 14 13 12 11 10 9 Bit 8 Bit 7 6 5 4 3 2 1 Bit 0 — — — — — — — — — — — — — — — — MC9S08AW60 Data Sheet, Rev.1.0 46 Freescale Semiconductor Chapter 4 Memory High-page registers, shown in Table 4-3, are accessed much less often than other I/O and control registers so they have been located outside the direct addressable memory space, starting at $1800. Table 4-3. High-Page Register Summary (Sheet 1 of 2) Address $1800 $1801 $1802 $1803 $1804 – $1805 $1806 $1807 $1808 $1809 $180A $180B– $180F $1810 $1811 $1812 $1813 $1814 $1815 $1816 $1817 $1818 $1819– $181F $1820 $1821 $1822 $1823 $1824 $1825 $1826 $1827– $183F $1840 $1841 $1842 $1843 $1844 $1845 Register Name SRS SBDFR SOPT SMCLK Reserved SDIDH SDIDL SRTISC SPMSC1 SPMSC2 Reserved DBGCAH DBGCAL DBGCBH DBGCBL DBGFH DBGFL DBGC DBGT DBGS Reserved FCDIV FOPT Reserved FCNFG FPROT FSTAT FCMD Reserved PTAPE PTASE PTADS Reserved PTBPE PTBSE Bit 7 6 5 4 3 2 1 Bit 0 POR PIN COP ILOP 0 ICG LVD 0 0 0 0 0 0 0 0 BDFR COPE COPT STOPE — 0 0 — — 0 0 0 MPE 0 — — — — — — — — — — — — — — — — REV3 REV2 REV1 REV0 ID11 ID10 ID9 ID8 ID7 ID6 ID5 ID4 ID3 ID2 ID1 ID0 MCSEL RTIF RTIACK RTICLKS RTIE 0 RTIS2 RTIS1 RTIS0 LVDF LVDACK LVDIE LVDRE LVDSE LVDE 01 BGBE LVWF LVWACK LVDV LVWV PPDF PPDACK — PPDC — — — — — — — — — — — — — — — — Bit 15 14 13 12 11 10 9 Bit 8 Bit 7 6 5 4 3 2 1 Bit 0 Bit 15 14 13 12 11 10 9 Bit 8 Bit 7 6 5 4 3 2 1 Bit 0 Bit 15 14 13 12 11 10 9 Bit 8 Bit 7 6 5 4 3 2 1 Bit 0 DBGEN ARM TAG BRKEN RWA RWAEN RWB RWBEN TRGSEL BEGIN 0 0 TRG3 TRG2 TRG1 TRG0 AF BF ARMF 0 CNT3 CNT2 CNT1 CNT0 — — — — — — — — — — — — — — — — DIVLD PRDIV8 DIV5 DIV4 DIV3 DIV2 DIV1 DIV0 KEYEN FNORED 0 0 0 0 SEC01 SEC00 — — — — — — — — 0 0 KEYACC 0 0 0 0 0 FPS7 FPS6 FPS5 FPS4 FPS3 FPS2 FPS1 FPDIS FCBEF FCCF FPVIOL FACCERR 0 FBLANK 0 0 FCMD7 FCMD6 FCMD5 FCMD4 FCMD3 FCMD2 FCMD1 FCMD0 — — — — — — — — — — — — — — — — PTAPE7 PTAPE6 PTAPE5 PTAPE4 PTAPE3 PTAPE2 PTAPE1 PTAPE0 PTASE7 PTASE6 PTASE5 PTASE4 PTASE3 PTASE2 PTASE1 PTASE0 PTADS7 PTADS6 PTADS5 PTADS4 PTADS3 PTADS2 PTADS1 PTADS0 — — — — — — — — PTBPE7 PTBPE6 PTBPE5 PTBPE4 PTBPE3 PTBPE2 PTBPE1 PTBPE0 PTBSE7 PTBSE6 PTBSE5 PTBSE4 PTBSE3 PTBSE2 PTBSE1 PTBSE0 MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 47 Chapter 4 Memory Table 4-3. High-Page Register Summary (Sheet 2 of 2) Address $1846 $1847 $1848 $1849 $184A $184B $184C $184D $184E $184F $1850 $1851 $1852 $1853 $1854 $1855 $1856 $1857 $1858 $1859 $185A $185B– $185F 1 Register Name PTBDS Reserved PTCPE PTCSE PTCDS Reserved PTDPE PTDSE PTDDS Reserved PTEPE PTESE PTEDS Reserved PTFPE PTFSE PTFDS Reserved PTGPE PTGSE PTGDS Reserved Bit 7 6 5 4 3 2 1 Bit 0 PTBDS7 PTBDS6 PTBDS5 PTBDS4 PTBDS3 PTBDS2 PTBDS1 PTBDS0 — — — — — — — — 0 PTCPE6 PTCPE5 PTCPE4 PTCPE3 PTCPE2 PTCPE1 PTCPE0 0 PTCSE6 PTCSE5 PTCSE4 PTCSE3 PTCSE2 PTCSE1 PTCSE0 0 PTCDS6 PTCDS5 PTCDS4 PTCDS3 PTCDS2 PTCDS1 PTCDS0 — — — — — — — — PTDPE7 PTDPE6 PTDPE5 PTDPE4 PTDPE3 PTDPE2 PTDPE1 PTDPE0 PTDSE7 PTDSE6 PTDSE5 PTDSE4 PTDSE3 PTDSE2 PTDSE1 PTDSE0 PTDDS7 PTDDS6 PTDDS5 PTDDS4 PTDDS3 PTDDS2 PTDDS1 PTDDS0 — — — — — — — — PTEPE7 PTEPE6 PTEPE5 PTEPE4 PTEPE3 PTEPE2 PTEPE1 PTEPE0 PTESE7 PTESE6 PTESE5 PTESE4 PTESE3 PTESE2 PTESE1 PTESE0 PTEDS7 PTEDS6 PTEDS5 PTEDS4 PTEDS3 PTEDS2 PTEDS1 PTEDS0 — — — — — — — — PTFPE7 PTFPE6 PTFPE5 PTFPE4 PTFPE3 PTFPE2 PTFPE1 PTFPE0 PTFSE7 PTFSE6 PTFSE5 PTFSE4 PTFSE3 PTFSE2 PTFSE1 PTFSE0 PTFDS7 PTFDS6 PTFDS5 PTFDS4 PTFDS3 PTFDS2 PTFDS1 PTFDS0 — — — — — — — — 0 PTGPE6 PTGPE5 PTGPE4 PTGPE3 PTGPE2 PTGPE1 PTGPE0 0 PTGSE6 PTGSE5 PTGSE4 PTGSE3 PTGSE2 PTGSE1 PTGSE0 0 PTGDS6 PTGDS5 PTGDS4 PTGDS3 PTGDS2 PTGDS1 PTGDS0 — — — — — — — — — — — — — — — — This reserved bit must always be written to 0. Nonvolatile FLASH registers, shown in Table 4-4, are located in the FLASH memory. These registers include an 8-byte backdoor key which optionally can be used to gain access to secure memory resources. During reset events, the contents of NVPROT and NVOPT in the nonvolatile register area of the FLASH memory are transferred into corresponding FPROT and FOPT working registers in the high-page registers to control security and block protection options. Table 4-4. Nonvolatile Register Summary Address $FFB0 – $FFB7 $FFB8 – $FFBC $FFBD $FFBE $FFBF 1 Register Name Bit 7 6 5 NVBACKKEY 4 3 2 1 Bit 0 8-Byte Comparison Key Reserved — — — — — — — — — — — — — — — — NVPROT Reserved1 NVOPT FPS7 FPS6 FPS5 FPS4 FPS3 FPS2 FPS1 FPDIS — — — — — — — — KEYEN FNORED 0 0 0 0 SEC01 SEC00 This location can be used to store the factory trim value for the ICG. MC9S08AW60 Data Sheet, Rev.1.0 48 Freescale Semiconductor Chapter 4 Memory Provided the key enable (KEYEN) bit is 1, the 8-byte comparison key can be used to temporarily disengage memory security. This key mechanism can be accessed only through user code running in secure memory. (A security key cannot be entered directly through background debug commands.) This security key can be disabled completely by programming the KEYEN bit to 0. If the security key is disabled, the only way to disengage security is by mass erasing the FLASH if needed (normally through the background debug interface) and verifying that FLASH is blank. To avoid returning to secure mode after the next reset, program the security bits (SEC01:SEC00) to the unsecured state (1:0). 4.3 RAM The MC9S08AW60/48/32/16 includes static RAM. The locations in RAM below $0100 can be accessed using the more efficient direct addressing mode, and any single bit in this area can be accessed with the bit manipulation instructions (BCLR, BSET, BRCLR, and BRSET). Locating the most frequently accessed program variables in this area of RAM is preferred. The RAM retains data when the MCU is in low-power wait, stop2, or stop3 mode. At power-on, the contents of RAM are uninitialized. RAM data is unaffected by any reset provided that the supply voltage does not drop below the minimum value for RAM retention. For compatibility with older M68HC05 MCUs, the HCS08 resets the stack pointer to $00FF. In the MC9S08AW60/48/32/16, it is usually best to re-initialize the stack pointer to the top of the RAM so the direct page RAM can be used for frequently accessed RAM variables and bit-addressable program variables. Include the following 2-instruction sequence in your reset initialization routine (where RamLast is equated to the highest address of the RAM in the Freescale-provided equate file). LDHX TXS #RamLast+1 ;point one past RAM ;SP<-(H:X-1) When security is enabled, the RAM is considered a secure memory resource and is not accessible through BDM or through code executing from non-secure memory. See Section 4.5, “Security” for a detailed description of the security feature. 4.4 FLASH The FLASH memory is intended primarily for program storage. In-circuit programming allows the operating program to be loaded into the FLASH memory after final assembly of the application product. It is possible to program the entire array through the single-wire background debug interface. Because no special voltages are needed for FLASH erase and programming operations, in-application programming is also possible through other software-controlled communication paths. For a more detailed discussion of in-circuit and in-application programming, refer to the HCS08 Family Reference Manual, Volume I, Freescale Semiconductor document order number HCS08RMv1/D. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 49 Chapter 4 Memory 4.4.1 Features Features of the FLASH memory include: • FLASH Size — MC9S08AW60 — 63280 bytes (124 pages of 512 bytes each) — MC9S08AW48 — 49152 bytes (96 pages of 512 bytes each) — MC9S08AW32 — 32768 bytes (64 pages of 512 bytes each) • Single power supply program and erase • Command interface for fast program and erase operation • Up to 100,000 program/erase cycles at typical voltage and temperature • Flexible block protection • Security feature for FLASH and RAM • Auto power-down for low-frequency read accesses 4.4.2 Program and Erase Times Before any program or erase command can be accepted, the FLASH clock divider register (FCDIV) must be written to set the internal clock for the FLASH module to a frequency (fFCLK) between 150 kHz and 200 kHz (see Section 4.6.1, “FLASH Clock Divider Register (FCDIV)”). This register can be written only once, so normally this write is done during reset initialization. FCDIV cannot be written if the access error flag, FACCERR in FSTAT, is set. The user must ensure that FACCERR is not set before writing to the FCDIV register. One period of the resulting clock (1/fFCLK) is used by the command processor to time program and erase pulses. An integer number of these timing pulses are used by the command processor to complete a program or erase command. Table 4-5 shows program and erase times. The bus clock frequency and FCDIV determine the frequency of FCLK (fFCLK). The time for one cycle of FCLK is tFCLK = 1/fFCLK. The times are shown as a number of cycles of FCLK and as an absolute time for the case where tFCLK = 5 µs. Program and erase times shown include overhead for the command state machine and enabling and disabling of program and erase voltages. Table 4-5. Program and Erase Times Parameter 1 2 Cycles of FCLK Time if FCLK = 200 kHz Byte program 9 45 µs Byte program (burst) 4 20 µs1 Page erase 4000 20 ms2 Mass erase 20,000 100 ms2 Excluding start/end overhead Because the page and mass erase times can be longer than the COP watchdog timeout, the COP should be serviced during any software erase routine. MC9S08AW60 Data Sheet, Rev.1.0 50 Freescale Semiconductor Chapter 4 Memory 4.4.3 Program and Erase Command Execution The steps for executing any of the commands are listed below. The FCDIV register must be initialized and any error flags cleared before beginning command execution. The command execution steps are: 1. Write a data value to an address in the FLASH array. The address and data information from this write is latched into the FLASH interface. This write is a required first step in any command sequence. For erase and blank check commands, the value of the data is not important. For page erase commands, the address may be any address in the 512-byte page of FLASH to be erased. For mass erase and blank check commands, the address can be any address in the FLASH memory. Whole pages of 512 bytes are the smallest block of FLASH that may be erased. In the 60K version, there are two instances where the size of a block that is accessible to the user is less than 512 bytes: the first page following RAM, and the first page following the high page registers. These pages are overlapped by the RAM and high page registers respectively. NOTE Do not program any byte in the FLASH more than once after a successful erase operation. Reprogramming bits to a byte which is already programmed is not allowed without first erasing the page in which the byte resides or mass erasing the entire FLASH memory. Programming without first erasing may disturb data stored in the FLASH. 2. Write the command code for the desired command to FCMD. The five valid commands are blank check ($05), byte program ($20), burst program ($25), page erase ($40), and mass erase ($41). The command code is latched into the command buffer. 3. Write a 1 to the FCBEF bit in FSTAT to clear FCBEF and launch the command (including its address and data information). A partial command sequence can be aborted manually by writing a 0 to FCBEF any time after the write to the memory array and before writing the 1 that clears FCBEF and launches the complete command. Aborting a command in this way sets the FACCERR access error flag which must be cleared before starting a new command. A strictly monitored procedure must be obeyed or the command will not be accepted. This minimizes the possibility of any unintended changes to the FLASH memory contents. The command complete flag (FCCF) indicates when a command is complete. The command sequence must be completed by clearing FCBEF to launch the command. Figure 4-3 is a flowchart for executing all of the commands except for burst programming. The FCDIV register must be initialized before using any FLASH commands. This only must be done once following a reset. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 51 Chapter 4 Memory WRITE TO FCDIV (Note 1) FLASH PROGRAM AND ERASE FLOW Note 1: Required only once after reset. START FACCERR ? 0 1 CLEAR ERROR WRITE TO FLASH TO BUFFER ADDRESS AND DATA WRITE COMMAND TO FCMD WRITE 1 TO FCBEF TO LAUNCH COMMAND AND CLEAR FCBEF (Note 2) FPVIOL OR FACCERR ? Note 2: Wait at least four bus cycles before checking FCBEF or FCCF. YES ERROR EXIT NO 0 FCCF ? 1 DONE Figure 4-3. FLASH Program and Erase Flowchart 4.4.4 Burst Program Execution The burst program command is used to program sequential bytes of data in less time than would be required using the standard program command. This is possible because the high voltage to the FLASH array does not need to be disabled between program operations. Ordinarily, when a program or erase command is issued, an internal charge pump associated with the FLASH memory must be enabled to supply high voltage to the array. Upon completion of the command, the charge pump is turned off. When a burst program command is issued, the charge pump is enabled and then remains enabled after completion of the burst program operation if these two conditions are met: • The next burst program command has been queued before the current program operation has completed. • The next sequential address selects a byte on the same physical row as the current byte being programmed. A row of FLASH memory consists of 64 bytes. A byte within a row is selected by addresses A5 through A0. A new row begins when addresses A5 through A0 are all zero. MC9S08AW60 Data Sheet, Rev.1.0 52 Freescale Semiconductor Chapter 4 Memory The first byte of a series of sequential bytes being programmed in burst mode will take the same amount of time to program as a byte programmed in standard mode. Subsequent bytes will program in the burst program time provided that the conditions above are met. In the case the next sequential address is the beginning of a new row, the program time for that byte will be the standard time instead of the burst time. This is because the high voltage to the array must be disabled and then enabled again. If a new burst command has not been queued before the current command completes, then the charge pump will be disabled and high voltage removed from the array. Note 1: Required only once after reset. WRITE TO FCDIV (Note 1) FLASH BURST PROGRAM FLOW START FACCERR ? 1 0 CLEAR ERROR FCBEF ? 1 0 WRITE TO FLASH TO BUFFER ADDRESS AND DATA WRITE COMMAND ($25) TO FCMD WRITE 1 TO FCBEF TO LAUNCH COMMAND AND CLEAR FCBEF (Note 2) FPVIO OR FACCERR ? NO YES Note 2: Wait at least four bus cycles before checking FCBEF or FCCF. YES ERROR EXIT NEW BURST COMMAND ? NO 0 FCCF ? 1 DONE Figure 4-4. FLASH Burst Program Flowchart MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 53 Chapter 4 Memory 4.4.5 Access Errors An access error occurs whenever the command execution protocol is violated. Any of the following specific actions will cause the access error flag (FACCERR) in FSTAT to be set. FACCERR must be cleared by writing a 1 to FACCERR in FSTAT before any command can be processed. • Writing to a FLASH address before the internal FLASH clock frequency has been set by writing to the FCDIV register • Writing to a FLASH address while FCBEF is not set (A new command cannot be started until the command buffer is empty.) • Writing a second time to a FLASH address before launching the previous command (There is only one write to FLASH for every command.) • Writing a second time to FCMD before launching the previous command (There is only one write to FCMD for every command.) • Writing to any FLASH control register other than FCMD after writing to a FLASH address • Writing any command code other than the five allowed codes ($05, $20, $25, $40, or $41) to FCMD • Accessing (read or write) any FLASH control register other than the write to FSTAT (to clear FCBEF and launch the command) after writing the command to FCMD. • The MCU enters stop mode while a program or erase command is in progress (The command is aborted.) • Writing the byte program, burst program, or page erase command code ($20, $25, or $40) with a background debug command while the MCU is secured (The background debug controller can only do blank check and mass erase commands when the MCU is secure.) • Writing 0 to FCBEF to cancel a partial command 4.4.6 FLASH Block Protection The block protection feature prevents the protected region of FLASH from program or erase changes. Block protection is controlled through the FLASH Protection Register (FPROT). When enabled, block protection begins at any 512 byte boundary below the last address of FLASH, $FFFF. (see Section 4.6.4, “FLASH Protection Register (FPROT and NVPROT)”). After exit from reset, FPROT is loaded with the contents of the NVPROT location which is in the nonvolatile register block of the FLASH memory. FPROT cannot be changed directly from application software so a runaway program cannot alter the block protection settings. Since NVPROT is within the last 512 bytes of FLASH, if any amount of memory is protected, NVPROT is itself protected and cannot be altered (intentionally or unintentionally) by the application software. FPROT can be written through background debug commands which allows a way to erase and reprogram a protected FLASH memory. The block protection mechanism is illustrated below. The FPS bits are used as the upper bits of the last address of unprotected memory. This address is formed by concatenating FPS7:FPS1 with logic 1 bits as shown. For example, in order to protect the last 8192 bytes of memory (addresses $E000 through $FFFF), the FPS bits must be set to 1101 111 which results in the value $DFFF as the last address of unprotected memory. In addition to programming the FPS bits to the appropriate value, FPDIS (bit 0 of NVPROT) must MC9S08AW60 Data Sheet, Rev.1.0 54 Freescale Semiconductor Chapter 4 Memory be programmed to logic 0 to enable block protection. Therefore the value $DE must be programmed into NVPROT to protect addresses $E000 through $FFFF. FPS7 FPS6 FPS5 FPS4 FPS3 FPS2 FPS1 A15 A14 A13 A12 A11 A10 A9 1 1 1 1 1 1 1 1 1 A8 A7 A6 A5 A4 A3 A2 A1 A0 Figure 4-5. Block Protection Mechanism One use for block protection is to block protect an area of FLASH memory for a bootloader program. This bootloader program then can be used to erase the rest of the FLASH memory and reprogram it. Because the bootloader is protected, it remains intact even if MCU power is lost in the middle of an erase and reprogram operation. 4.4.7 Vector Redirection Whenever any block protection is enabled, the reset and interrupt vectors will be protected. Vector redirection allows users to modify interrupt vector information without unprotecting bootloader and reset vector space. Vector redirection is enabled by programming the FNORED bit in the NVOPT register located at address $FFBF to zero. For redirection to occur, at least some portion but not all of the FLASH memory must be block protected by programming the NVPROT register located at address $FFBD. All of the interrupt vectors (memory locations $FFC0–$FFFD) are redirected, though the reset vector ($FFFE:FFFF) is not. For example, if 512 bytes of FLASH are protected, the protected address region is from $FE00 through $FFFF. The interrupt vectors ($FFC0–$FFFD) are redirected to the locations $FDC0–$FDFD. Now, if an SPI interrupt is taken for instance, the values in the locations $FDE0:FDE1 are used for the vector instead of the values in the locations $FFE0:FFE1. This allows the user to reprogram the unprotected portion of the FLASH with new program code including new interrupt vector values while leaving the protected area, which includes the default vector locations, unchanged. 4.5 Security The MC9S08AW60/48/32/16 includes circuitry to prevent unauthorized access to the contents of FLASH and RAM memory. When security is engaged, FLASH and RAM are considered secure resources. Direct-page registers, high-page registers, and the background debug controller are considered unsecured resources. Programs executing within secure memory have normal access to any MCU memory locations and resources. Attempts to access a secure memory location with a program executing from an unsecured memory space or through the background debug interface are blocked (writes are ignored and reads return all 0s). Security is engaged or disengaged based on the state of two nonvolatile register bits (SEC01:SEC00) in the FOPT register. During reset, the contents of the nonvolatile location NVOPT are copied from FLASH into the working FOPT register in high-page register space. A user engages security by programming the NVOPT location which can be done at the same time the FLASH memory is programmed. The 1:0 state disengages security and the other three combinations engage security. Notice the erased state (1:1) makes MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 55 Chapter 4 Memory the MCU secure. During development, whenever the FLASH is erased, it is good practice to immediately program the SEC00 bit to 0 in NVOPT so SEC01:SEC00 = 1:0. This would allow the MCU to remain unsecured after a subsequent reset. The on-chip debug module cannot be enabled while the MCU is secure. The separate background debug controller can still be used for background memory access commands, but the MCU cannot enter active background mode except by holding BKGD/MS low at the rising edge of reset. A user can choose to allow or disallow a security unlocking mechanism through an 8-byte backdoor security key. If the nonvolatile KEYEN bit in NVOPT/FOPT is 0, the backdoor key is disabled and there is no way to disengage security without completely erasing all FLASH locations. If KEYEN is 1, a secure user program can temporarily disengage security by: 1. Writing 1 to KEYACC in the FCNFG register. This makes the FLASH module interpret writes to the backdoor comparison key locations (NVBACKKEY through NVBACKKEY+7) as values to be compared against the key rather than as the first step in a FLASH program or erase command. 2. Writing the user-entered key values to the NVBACKKEY through NVBACKKEY+7 locations. These writes must be done in order starting with the value for NVBACKKEY and ending with NVBACKKEY+7. STHX should not be used for these writes because these writes cannot be done on adjacent bus cycles. User software normally would get the key codes from outside the MCU system through a communication interface such as a serial I/O. 3. Writing 0 to KEYACC in the FCNFG register. If the 8-byte key that was just written matches the key stored in the FLASH locations, SEC01:SEC00 are automatically changed to 1:0 and security will be disengaged until the next reset. The security key can be written only from secure memory (either RAM or FLASH), so it cannot be entered through background commands without the cooperation of a secure user program. The backdoor comparison key (NVBACKKEY through NVBACKKEY+7) is located in FLASH memory locations in the nonvolatile register space so users can program these locations exactly as they would program any other FLASH memory location. The nonvolatile registers are in the same 512-byte block of FLASH as the reset and interrupt vectors, so block protecting that space also block protects the backdoor comparison key. Block protects cannot be changed from user application programs, so if the vector space is block protected, the backdoor security key mechanism cannot permanently change the block protect, security settings, or the backdoor key. Security can always be disengaged through the background debug interface by taking these steps: 1. Disable any block protections by writing FPROT. FPROT can be written only with background debug commands, not from application software. 2. Mass erase FLASH if necessary. 3. Blank check FLASH. Provided FLASH is completely erased, security is disengaged until the next reset. To avoid returning to secure mode after the next reset, program NVOPT so SEC01:SEC00 = 1:0. MC9S08AW60 Data Sheet, Rev.1.0 56 Freescale Semiconductor Chapter 4 Memory 4.6 FLASH Registers and Control Bits The FLASH module has nine 8-bit registers in the high-page register space, three locations in the nonvolatile register space in FLASH memory which are copied into three corresponding high-page control registers at reset. There is also an 8-byte comparison key in FLASH memory. Refer to Table 4-3 and Table 4-4 for the absolute address assignments for all FLASH registers. This section refers to registers and control bits only by their names. A Freescale-provided equate or header file normally is used to translate these names into the appropriate absolute addresses. 4.6.1 FLASH Clock Divider Register (FCDIV) Bit 7 of this register is a read-only status flag. Bits 6 through 0 may be read at any time but can be written only one time. Before any erase or programming operations are possible, write to this register to set the frequency of the clock for the nonvolatile memory system within acceptable limits. 7 R 6 5 4 3 2 1 0 PRDIV8 DIV5 DIV4 DIV3 DIV2 DIV1 DIV0 0 0 0 0 0 0 0 DIVLD W Reset 0 = Unimplemented or Reserved Figure 4-6. FLASH Clock Divider Register (FCDIV) Table 4-6. FCDIV Register Field Descriptions Field Description 7 DIVLD Divisor Loaded Status Flag — When set, this read-only status flag indicates that the FCDIV register has been written since reset. Reset clears this bit and the first write to this register causes this bit to become set regardless of the data written. 0 FCDIV has not been written since reset; erase and program operations disabled for FLASH. 1 FCDIV has been written since reset; erase and program operations enabled for FLASH. 6 PRDIV8 Prescale (Divide) FLASH Clock by 8 0 Clock input to the FLASH clock divider is the bus rate clock. 1 Clock input to the FLASH clock divider is the bus rate clock divided by 8. 5:0 DIV[5:0] Divisor for FLASH Clock Divider — The FLASH clock divider divides the bus rate clock (or the bus rate clock divided by 8 if PRDIV8 = 1) by the value in the 6-bit DIV5:DIV0 field plus one. The resulting frequency of the internal FLASH clock must fall within the range of 200 kHz to 150 kHz for proper FLASH operations. Program/Erase timing pulses are one cycle of this internal FLASH clock which corresponds to a range of 5 µs to 6.7 µs. The automated programming logic uses an integer number of these pulses to complete an erase or program operation. See Equation 4-1, Equation 4-2, and Table 4-6. if PRDIV8 = 0 — fFCLK = fBus ÷ ([DIV5:DIV0] + 1) Eqn. 4-1 if PRDIV8 = 1 — fFCLK = fBus ÷ (8 × ([DIV5:DIV0] + 1)) Eqn. 4-2 Table 4-7 shows the appropriate values for PRDIV8 and DIV5:DIV0 for selected bus frequencies. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 57 Chapter 4 Memory Table 4-7. FLASH Clock Divider Settings fBus PRDIV8 (Binary) DIV5:DIV0 (Decimal) fFCLK Program/Erase Timing Pulse (5 µs Min, 6.7 µs Max) 20 MHz 1 12 192.3 kHz 5.2 µs 10 MHz 0 49 200 kHz 5 µs 8 MHz 0 39 200 kHz 5 µs 4 MHz 0 19 200 kHz 5 µs 2 MHz 0 9 200 kHz 5 µs 1 MHz 0 4 200 kHz 5 µs 200 kHz 0 0 200 kHz 5 µs 150 kHz 0 0 150 kHz 6.7 µs 4.6.2 FLASH Options Register (FOPT and NVOPT) During reset, the contents of the nonvolatile location NVOPT are copied from FLASH into FOPT. Bits 5 through 2 are not used and always read 0. This register may be read at any time, but writes have no meaning or effect. To change the value in this register, erase and reprogram the NVOPT location in FLASH memory as usual and then issue a new MCU reset. R 7 6 5 4 3 2 1 0 KEYEN FNORED 0 0 0 0 SEC01 SEC00 W Reset This register is loaded from nonvolatile location NVOPT during reset. = Unimplemented or Reserved Figure 4-7. FLASH Options Register (FOPT) Table 4-8. FOPT Register Field Descriptions Field Description 7 KEYEN Backdoor Key Mechanism Enable — When this bit is 0, the backdoor key mechanism cannot be used to disengage security. The backdoor key mechanism is accessible only from user (secured) firmware. BDM commands cannot be used to write key comparison values that would unlock the backdoor key. For more detailed information about the backdoor key mechanism, refer to Section 4.5, “Security.” 0 No backdoor key access allowed. 1 If user firmware writes an 8-byte value that matches the nonvolatile backdoor key (NVBACKKEY through NVBACKKEY+7 in that order), security is temporarily disengaged until the next MCU reset. 6 FNORED Vector Redirection Disable — When this bit is 1, then vector redirection is disabled. 0 Vector redirection enabled. 1 Vector redirection disabled. 1:0 SEC0[1:0] Security State Code — This 2-bit field determines the security state of the MCU as shown in Table 4-9. When the MCU is secure, the contents of RAM and FLASH memory cannot be accessed by instructions from any unsecured source including the background debug interface. For more detailed information about security, refer to Section 4.5, “Security.” MC9S08AW60 Data Sheet, Rev.1.0 58 Freescale Semiconductor Chapter 4 Memory Table 4-9. Security States SEC01:SEC00 Description 0:0 secure 0:1 secure 1:0 unsecured 1:1 secure SEC01:SEC00 changes to 1:0 after successful backdoor key entry or a successful blank check of FLASH. 4.6.3 FLASH Configuration Register (FCNFG) Bits 7 through 5 may be read or written at any time. Bits 4 through 0 always read 0 and cannot be written. R 7 6 0 0 5 4 3 2 1 0 0 0 0 0 0 0 0 0 0 0 KEYACC W Reset 0 0 0 = Unimplemented or Reserved Figure 4-8. FLASH Configuration Register (FCNFG) Table 4-10. FCNFG Register Field Descriptions Field Description 5 KEYACC Enable Writing of Access Key — This bit enables writing of the backdoor comparison key. For more detailed information about the backdoor key mechanism, refer to Section 4.5, “Security.” 0 Writes to $FFB0–$FFB7 are interpreted as the start of a FLASH programming or erase command. 1 Writes to NVBACKKEY ($FFB0–$FFB7) are interpreted as comparison key writes. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 59 Chapter 4 Memory 4.6.4 FLASH Protection Register (FPROT and NVPROT) During reset, the contents of the nonvolatile location NVPROT is copied from FLASH into FPROT. Bits 0, 1, and 2 are not used and each always reads as 0. This register may be read at any time, but user program writes have no meaning or effect. Background debug commands can write to FPROT. 7 6 5 4 3 2 1 0 R FPS7 FPS6 FPS5 FPS4 FPS3 FPS2 FPS1 FPDIS W (1) (1) (1) (1) (1) (1) (1) (1) Reset 1 This register is loaded from nonvolatile location NVPROT during reset. Background commands can be used to change the contents of these bits in FPROT. Figure 4-9. FLASH Protection Register (FPROT) Table 4-11. FPROT Register Field Descriptions Field Description 7:1 FPS[7:1] FLASH Protect Select Bits — When FPDIS = 0, this 7-bit field determines the ending address of unprotected FLASH locations at the high address end of the FLASH. Protected FLASH locations cannot be erased or programmed. 0 FPDIS 4.6.5 FLASH Protection Disable 0 FLASH block specified by FPS[7:1] is block protected (program and erase not allowed). 1 No FLASH block is protected. FLASH Status Register (FSTAT) Bits 3, 1, and 0 always read 0 and writes have no meaning or effect. The remaining five bits are status bits that can be read at any time. Writes to these bits have special meanings that are discussed in the bit descriptions. 7 R 6 5 4 FPVIOL FACCERR 0 0 FCCF FCBEF 3 2 1 0 0 FBLANK 0 0 0 0 0 0 W Reset 1 1 = Unimplemented or Reserved Figure 4-10. FLASH Status Register (FSTAT) MC9S08AW60 Data Sheet, Rev.1.0 60 Freescale Semiconductor Chapter 4 Memory Table 4-12. FSTAT Register Field Descriptions Field Description 7 FCBEF FLASH Command Buffer Empty Flag — The FCBEF bit is used to launch commands. It also indicates that the command buffer is empty so that a new command sequence can be executed when performing burst programming. The FCBEF bit is cleared by writing a one to it or when a burst program command is transferred to the array for programming. Only burst program commands can be buffered. 0 Command buffer is full (not ready for additional commands). 1 A new burst program command may be written to the command buffer. 6 FCCF FLASH Command Complete Flag — FCCF is set automatically when the command buffer is empty and no command is being processed. FCCF is cleared automatically when a new command is started (by writing 1 to FCBEF to register a command). Writing to FCCF has no meaning or effect. 0 Command in progress 1 All commands complete 5 FPVIOL Protection Violation Flag — FPVIOL is set automatically when FCBEF is cleared to register a command that attempts to erase or program a location in a protected block (the erroneous command is ignored). FPVIOL is cleared by writing a 1 to FPVIOL. 0 No protection violation. 1 An attempt was made to erase or program a protected location. 4 FACCERR Access Error Flag — FACCERR is set automatically when the proper command sequence is not obeyed exactly (the erroneous command is ignored), if a program or erase operation is attempted before the FCDIV register has been initialized, or if the MCU enters stop while a command was in progress. For a more detailed discussion of the exact actions that are considered access errors, see Section 4.4.5, “Access Errors.” FACCERR is cleared by writing a 1 to FACCERR. Writing a 0 to FACCERR has no meaning or effect. 0 No access error. 1 An access error has occurred. 2 FBLANK FLASH Verified as All Blank (erased) Flag — FBLANK is set automatically at the conclusion of a blank check command if the entire FLASH array was verified to be erased. FBLANK is cleared by clearing FCBEF to write a new valid command. Writing to FBLANK has no meaning or effect. 0 After a blank check command is completed and FCCF = 1, FBLANK = 0 indicates the FLASH array is not completely erased. 1 After a blank check command is completed and FCCF = 1, FBLANK = 1 indicates the FLASH array is completely erased (all $FF). MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 61 Chapter 4 Memory 4.6.6 FLASH Command Register (FCMD) Only five command codes are recognized in normal user modes as shown in Table 4-14. Refer to Section 4.4.3, “Program and Erase Command Execution” for a detailed discussion of FLASH programming and erase operations. 7 6 5 4 3 2 1 0 R 0 0 0 0 0 0 0 0 W FCMD7 FCMD6 FCMD5 FCMD4 FCMD3 FCMD2 FCMD1 FCMD0 0 0 0 0 0 0 0 0 Reset Figure 4-11. FLASH Command Register (FCMD) Table 4-13. FCMD Register Field Descriptions Field FCMD[7:0] Description FLASH Command Bits — See Table 4-14 Table 4-14. FLASH Commands Command FCMD Equate File Label Blank check $05 mBlank Byte program $20 mByteProg Byte program — burst mode $25 mBurstProg Page erase (512 bytes/page) $40 mPageErase Mass erase (all FLASH) $41 mMassErase All other command codes are illegal and generate an access error. It is not necessary to perform a blank check command after a mass erase operation. Only blank check is required as part of the security unlocking mechanism. MC9S08AW60 Data Sheet, Rev.1.0 62 Freescale Semiconductor Chapter 5 Resets, Interrupts, and System Configuration 5.1 Introduction This chapter discusses basic reset and interrupt mechanisms and the various sources of reset and interrupts in the MC9S08AW60/48/32/16. Some interrupt sources from peripheral modules are discussed in greater detail within other chapters of this data manual. This chapter gathers basic information about all reset and interrupt sources in one place for easy reference. A few reset and interrupt sources, including the computer operating properly (COP) watchdog and real-time interrupt (RTI), are not part of on-chip peripheral systems with their own sections but are part of the system control logic. 5.2 Features Reset and interrupt features include: • Multiple sources of reset for flexible system configuration and reliable operation: — Power-on detection (POR) — Low voltage detection (LVD) with enable — External RESET pin — COP watchdog with enable and two timeout choices — Illegal opcode — Serial command from a background debug host • Reset status register (SRS) to indicate source of most recent reset • Separate interrupt vectors for each module (reduces polling overhead) (see Table 5-10) 5.3 MCU Reset Resetting the MCU provides a way to start processing from a known set of initial conditions. During reset, most control and status registers are forced to initial values and the program counter is loaded from the reset vector ($FFFE:$FFFF). On-chip peripheral modules are disabled and I/O pins are initially configured as general-purpose high-impedance inputs with pullup devices disabled. The I bit in the condition code register (CCR) is set to block maskable interrupts so the user program has a chance to initialize the stack pointer (SP) and system control settings. SP is forced to $00FF at reset. The MC9S08AW60/48/32/16 has seven sources for reset: • Power-on reset (POR) • Low-voltage detect (LVD) • Computer operating properly (COP) timer MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 63 Chapter 5 Resets, Interrupts, and System Configuration • • • • Illegal opcode detect Background debug forced reset The reset pin (RESET) Clock generator loss of lock and loss of clock reset Each of these sources, with the exception of the background debug forced reset, has an associated bit in the system reset status register. Whenever the MCU enters reset, the internal clock generator (ICG) module switches to self-clocked mode with the frequency of fSelf_reset selected. The reset pin is driven low for 34 bus cycles where the internal bus frequency is half the ICG frequency. After the 34 bus cycles are completed, the pin is released and will be pulled up by the internal pullup resistor, unless it is held low externally. After the pin is released, it is sampled after another 38 bus cycles to determine whether the reset pin is the cause of the MCU reset. 5.4 Computer Operating Properly (COP) Watchdog The COP watchdog is intended to force a system reset when the application software fails to execute as expected. To prevent a system reset from the COP timer (when it is enabled), application software must reset the COP timer periodically. If the application program gets lost and fails to reset the COP before it times out, a system reset is generated to force the system back to a known starting point. The COP watchdog is enabled by the COPE bit in SOPT (see Section 5.9.4, “System Options Register (SOPT)” for additional information). The COP timer is reset by writing any value to the address of SRS. This write does not affect the data in the read-only SRS. Instead, the act of writing to this address is decoded and sends a reset signal to the COP timer. After any reset, the COP timer is enabled. This provides a reliable way to detect code that is not executing as intended. If the COP watchdog is not used in an application, it can be disabled by clearing the COPE bit in the write-once SOPT register. Also, the COPT bit can be used to choose one of two timeout periods (218 or 213 cycles of the bus rate clock). Even if the application will use the reset default settings in COPE and COPT, the user should write to write-once SOPT during reset initialization to lock in the settings. That way, they cannot be changed accidentally if the application program gets lost. The write to SRS that services (clears) the COP timer should not be placed in an interrupt service routine (ISR) because the ISR could continue to be executed periodically even if the main application program fails. When the MCU is in active background mode, the COP timer is temporarily disabled. 5.5 Interrupts Interrupts provide a way to save the current CPU status and registers, execute an interrupt service routine (ISR), and then restore the CPU status so processing resumes where it left off before the interrupt. Other than the software interrupt (SWI), which is a program instruction, interrupts are caused by hardware events such as an edge on the IRQ pin or a timer-overflow event. The debug module can also generate an SWI under certain circumstances. If an event occurs in an enabled interrupt source, an associated read-only status flag will become set. The CPU will not respond until and unless the local interrupt enable is a logic 1 to enable the interrupt. The MC9S08AW60 Data Sheet, Rev.1.0 64 Freescale Semiconductor Chapter 5 Resets, Interrupts, and System Configuration I bit in the CCR is 0 to allow interrupts. The global interrupt mask (I bit) in the CCR is initially set after reset which masks (prevents) all maskable interrupt sources. The user program initializes the stack pointer and performs other system setup before clearing the I bit to allow the CPU to respond to interrupts. When the CPU receives a qualified interrupt request, it completes the current instruction before responding to the interrupt. The interrupt sequence obeys the same cycle-by-cycle sequence as the SWI instruction and consists of: • Saving the CPU registers on the stack • Setting the I bit in the CCR to mask further interrupts • Fetching the interrupt vector for the highest-priority interrupt that is currently pending • Filling the instruction queue with the first three bytes of program information starting from the address fetched from the interrupt vector locations While the CPU is responding to the interrupt, the I bit is automatically set to avoid the possibility of another interrupt interrupting the ISR itself (this is called nesting of interrupts). Normally, the I bit is restored to 0 when the CCR is restored from the value stacked on entry to the ISR. In rare cases, the I bit may be cleared inside an ISR (after clearing the status flag that generated the interrupt) so that other interrupts can be serviced without waiting for the first service routine to finish. This practice is not recommended for anyone other than the most experienced programmers because it can lead to subtle program errors that are difficult to debug. The interrupt service routine ends with a return-from-interrupt (RTI) instruction which restores the CCR, A, X, and PC registers to their pre-interrupt values by reading the previously saved information off the stack. NOTE For compatibility with the M68HC08, the H register is not automatically saved and restored. It is good programming practice to push H onto the stack at the start of the interrupt service routine (ISR) and restore it immediately before the RTI that is used to return from the ISR. When two or more interrupts are pending when the I bit is cleared, the highest priority source is serviced first (see Table 5-1). 5.5.1 Interrupt Stack Frame Figure 5-1 shows the contents and organization of a stack frame. Before the interrupt, the stack pointer (SP) points at the next available byte location on the stack. The current values of CPU registers are stored on the stack starting with the low-order byte of the program counter (PCL) and ending with the CCR. After stacking, the SP points at the next available location on the stack which is the address that is one less than the address where the CCR was saved. The PC value that is stacked is the address of the instruction in the main program that would have executed next if the interrupt had not occurred. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 65 Chapter 5 Resets, Interrupts, and System Configuration TOWARD LOWER ADDRESSES UNSTACKING ORDER 7 0 SP AFTER INTERRUPT STACKING 5 1 CONDITION CODE REGISTER 4 2 ACCUMULATOR 3 3 INDEX REGISTER (LOW BYTE X)* 2 4 PROGRAM COUNTER HIGH 1 5 PROGRAM COUNTER LOW STACKING ORDER SP BEFORE THE INTERRUPT TOWARD HIGHER ADDRESSES * High byte (H) of index register is not automatically stacked. Figure 5-1. Interrupt Stack Frame When an RTI instruction is executed, these values are recovered from the stack in reverse order. As part of the RTI sequence, the CPU fills the instruction pipeline by reading three bytes of program information, starting from the PC address recovered from the stack. The status flag causing the interrupt must be acknowledged (cleared) before returning from the ISR. Typically, the flag should be cleared at the beginning of the ISR so that if another interrupt is generated by this same source, it will be registered so it can be serviced after completion of the current ISR. 5.5.2 External Interrupt Request (IRQ) Pin External interrupts are managed by the IRQSC status and control register. When the IRQ function is enabled, synchronous logic monitors the pin for edge-only or edge-and-level events. When the MCU is in stop mode and system clocks are shut down, a separate asynchronous path is used so the IRQ (if enabled) can wake the MCU. 5.5.2.1 Pin Configuration Options The IRQ pin enable (IRQPE) control bit in the IRQSC register must be 1 in order for the IRQ pin to act as the interrupt request (IRQ) input. As an IRQ input, the user can choose the polarity of edges or levels detected (IRQEDG), whether the pin detects edges-only or edges and levels (IRQMOD), and whether an event causes an interrupt or only sets the IRQF flag which can be polled by software. When the IRQ pin is configured to detect rising edges, an optional pulldown resistor is available rather than a pullup resistor. BIH and BIL instructions may be used to detect the level on the IRQ pin when the pin is configured to act as the IRQ input. MC9S08AW60 Data Sheet, Rev.1.0 66 Freescale Semiconductor Chapter 5 Resets, Interrupts, and System Configuration NOTE The voltage measured on the pulled up IRQ pin may be as low as VDD – 0.7 V. The internal gates connected to this pin are pulled all the way to VDD. All other pins with enabled pullup resistors will have an unloaded measurement of VDD. 5.5.2.2 Edge and Level Sensitivity The IRQMOD control bit reconfigures the detection logic so it detects edge events and pin levels. In this edge detection mode, the IRQF status flag becomes set when an edge is detected (when the IRQ pin changes from the deasserted to the asserted level), but the flag is continuously set (and cannot be cleared) as long as the IRQ pin remains at the asserted level. 5.5.3 Interrupt Vectors, Sources, and Local Masks Table 5-1 provides a summary of all interrupt sources. Higher-priority sources are located toward the bottom of the table. The high-order byte of the address for the interrupt service routine is located at the first address in the vector address column, and the low-order byte of the address for the interrupt service routine is located at the next higher address. When an interrupt condition occurs, an associated flag bit becomes set. If the associated local interrupt enable is 1, an interrupt request is sent to the CPU. Within the CPU, if the global interrupt mask (I bit in the CCR) is 0, the CPU will finish the current instruction, stack the PCL, PCH, X, A, and CCR CPU registers, set the I bit, and then fetch the interrupt vector for the highest priority pending interrupt. Processing then continues in the interrupt service routine. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 67 Chapter 5 Resets, Interrupts, and System Configuration Table 5-1. Vector Summary Vector Priority Vector Number Address (High/Low) Lower 26 through 31 25 $FFC0/FFC1 through $FFCA/FFCB $FFCC/FFCD Vrti 24 23 22 21 $FFCE/FFCF $FFD0/FFD1 $FFD2/FFD3 $FFD4/FFD5 Viic1 Vadc1 Vkeyboard 1 Vsci2tx System control IIC1 ADC1 KBI1 SCI2 20 $FFD6/FFD7 Vsci2rx SCI2 19 $FFD8/FFD9 Vsci2err SCI2 18 $FFDA/FFDB Vsci1tx SCI1 17 $FFDC/FFDD Vsci1rx SCI1 16 $FFDE/FFDF Vsci1err SCI1 15 $FFE0/FFE1 Vspi1 SPI1 14 13 12 11 10 9 8 7 6 5 4 $FFE2/FFE3 $FFE4/FFE5 $FFE6/FFE7 $FFE8/FFE9 $FFEA/FFEB $FFEC/FFED $FFEE/FFEF $FFF0/FFF1 $FFF2/FFF3 $FFF4/FFF5 $FFF6/FFF7 Vtpm2ovf Vtpm2ch1 Vtpm2ch0 Vtpm1ovf Vtpm1ch5 Vtpm1ch4 Vtpm1ch3 Vtpm1ch2 Vtpm1ch1 Vtpm1ch0 Vicg TPM2 TPM2 TPM2 TPM1 TPM1 TPM1 TPM1 TPM1 TPM1 TPM1 ICG 3 $FFF8/FFF9 Vlvd 2 1 $FFFA/FFFB $FFFC/FFFD Virq Vswi System control IRQ Core 0 $FFFE/FFFF Vreset Higher Vector Name Module Source Enable Description Unused Vector Space (available for user program) System control RTIF RTIE Real-time interrupt IICIF COCO KBF TDRE TC IDLE RDRF OR NF FE PF TDRE TC IDLE RDRF OR NF FE PF SPIF MODF SPTEF TOF CH1F CH0F TOF CH5F CH4F CH3F CH2F CH1F CH0F ICGIF (LOLS/LOCS) LVDF IICIE AIEN KBIE TIE TCIE ILIE RIE ORIE NFIE FEIE PFIE TIE TCIE ILIE RIE ORIE NFIE FEIE PFIE SPIE SPIE SPTIE TOIE CH1IE CH0IE TOIE CH5IE CH4IE CH3IE CH2IE CH1IE CH0IE LOLRE/LOCRE IIC1 ADC1 KBI1 pins SCI2 transmit TPM2 overflow TPM2 channel 1 TPM2 channel 0 TPM1 overflow TPM1 channel 5 TPM1 channel 4 TPM1 channel 3 TPM1 channel 2 TPM1 channel 1 TPM1 channel 0 ICG LVDIE Low-voltage detect IRQF SWI Instruction COP LVD RESET pin Illegal opcode IRQIE — IRQ pin Software interrupt COPE LVDRE — — Watchdog timer Low-voltage detect External pin Illegal opcode SCI2 receive SCI2 error SCI1 transmit SCI1 receive SCI1 error SPI1 MC9S08AW60 Data Sheet, Rev.1.0 68 Freescale Semiconductor Chapter 5 Resets, Interrupts, and System Configuration 5.6 Low-Voltage Detect (LVD) System The MC9S08AW60/48/32/16 includes a system to protect against low voltage conditions in order to protect memory contents and control MCU system states during supply voltage variations. The system is comprised of a power-on reset (POR) circuit and an LVD circuit with a user selectable trip voltage, either high (VLVDH) or low (VLVDL). The LVD circuit is enabled when LVDE in SPMSC1 is high and the trip voltage is selected by LVDV in SPMSC2. The LVD is disabled upon entering any of the stop modes unless the LVDSE bit is set. If LVDSE and LVDE are both set, then the MCU cannot enter stop2, and the current consumption in stop3 with the LVD enabled will be greater. 5.6.1 Power-On Reset Operation When power is initially applied to the MCU, or when the supply voltage drops below the VPOR level, the POR circuit will cause a reset condition. As the supply voltage rises, the LVD circuit will hold the chip in reset until the supply has risen above the VLVDL level. Both the POR bit and the LVD bit in SRS are set following a POR. 5.6.2 LVD Reset Operation The LVD can be configured to generate a reset upon detection of a low voltage condition by setting LVDRE to 1. After an LVD reset has occurred, the LVD system will hold the MCU in reset until the supply voltage has risen above the level determined by LVDV. The LVD bit in the SRS register is set following either an LVD reset or POR. 5.6.3 LVD Interrupt Operation When a low voltage condition is detected and the LVD circuit is configured for interrupt operation (LVDE set, LVDIE set, and LVDRE clear), then LVDF will be set and an LVD interrupt will occur. 5.6.4 Low-Voltage Warning (LVW) The LVD system has a low voltage warning flag to indicate to the user that the supply voltage is approaching, but is still above, the LVD voltage. The LVW does not have an interrupt associated with it. There are two user selectable trip voltages for the LVW, one high (VLVWH) and one low (VLVWL). The trip voltage is selected by LVWV in SPMSC2. 5.7 Real-Time Interrupt (RTI) The real-time interrupt function can be used to generate periodic interrupts. The RTI can accept two sources of clocks, the 1-kHz internal clock or an external clock if available. The 1-kHz internal clock source is completely independent of any bus clock source and is used only by the RTI module and, on some MCUs, the COP watchdog. To use an external clock source, it must be available and active. The RTICLKS bit in SRTISC is used to select the RTI clock source. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 69 Chapter 5 Resets, Interrupts, and System Configuration Either RTI clock source can be used when the MCU is in run, wait or stop3 mode. When using the external oscillator in stop3, it must be enabled in stop (OSCSTEN = 1) and configured for low bandwidth operation (RANGE = 0). Only the internal 1-kHz clock source can be selected to wake the MCU from stop2 mode. The SRTISC register includes a read-only status flag, a write-only acknowledge bit, and a 3-bit control value (RTIS2:RTIS1:RTIS0) used to disable the clock source to the real-time interrupt or select one of seven wakeup periods. The RTI has a local interrupt enable, RTIE, to allow masking of the real-time interrupt. The RTI can be disabled by writing each bit of RTIS to zeroes, and no interrupts will be generated. See Section 5.9.7, “System Real-Time Interrupt Status and Control Register (SRTISC),” for detailed information about this register. 5.8 MCLK Output The PTC2 pin is shared with the MCLK clock output. Setting the pin enable bit, MPE, causes the PTC2 pin to output a divided version of the internal MCU bus clock. The divide ratio is determined by the MCSEL bits. When MPE is set, the PTC2 pin is forced to operate as an output pin regardless of the state of the port data direction control bit for the pin. If the MCSEL bits are all 0s, the pin is driven low. The slew rate and drive strength for the pin are controlled by PTCSE2 and PTCDS2, respectively. The maximum clock output frequency is limited if slew rate control is enabled, see Appendix A, “Electrical Characteristics and Timing Specifications,” for pin rise and fall times with slew rate enabled. 5.9 Reset, Interrupt, and System Control Registers and Control Bits One 8-bit register in the direct page register space and eight 8-bit registers in the high-page register space are related to reset and interrupt systems. Refer to the direct-page register summary in Chapter 4, “Memory,” of this data sheet for the absolute address assignments for all registers. This section refers to registers and control bits only by their names. A Freescale-provided equate or header file is used to translate these names into the appropriate absolute addresses. Some control bits in the SOPT and SPMSC2 registers are related to modes of operation. Although brief descriptions of these bits are provided here, the related functions are discussed in greater detail in Chapter 3, “Modes of Operation.” MC9S08AW60 Data Sheet, Rev.1.0 70 Freescale Semiconductor Chapter 5 Resets, Interrupts, and System Configuration 5.9.1 Interrupt Pin Request Status and Control Register (IRQSC) This direct page register includes two unimplemented bits which always read 0, four read/write bits, one read-only status bit, and one write-only bit. These bits are used to configure the IRQ function, report status, and acknowledge IRQ events. R 7 6 0 0 5 4 IRQEDG IRQPE 3 2 IRQF 0 W Reset 1 0 IRQIE IRQMOD 0 0 IRQACK 0 0 0 0 0 0 = Unimplemented or Reserved Figure 5-2. Interrupt Request Status and Control Register (IRQSC) Table 5-2. IRQSC Register Field Descriptions Field Description 5 IRQEDG Interrupt Request (IRQ) Edge Select — This read/write control bit is used to select the polarity of edges or levels on the IRQ pin that cause IRQF to be set. The IRQMOD control bit determines whether the IRQ pin is sensitive to both edges and levels or only edges. When the IRQ pin is enabled as the IRQ input and is configured to detect rising edges, the optional pullup resistor is re-configured as an optional pulldown resistor. 0 IRQ is falling edge or falling edge/low-level sensitive. 1 IRQ is rising edge or rising edge/high-level sensitive. 4 IRQPE IRQ Pin Enable — This read/write control bit enables the IRQ pin function. When this bit is set the IRQ pin can be used as an interrupt request. Also, when this bit is set, either an internal pull-up or an internal pull-down resistor is enabled depending on the state of the IRQMOD bit. 0 IRQ pin function is disabled. 1 IRQ pin function is enabled. 3 IRQF 2 IRQACK 1 IRQIE 0 IRQMOD IRQ Flag — This read-only status bit indicates when an interrupt request event has occurred. 0 No IRQ request. 1 IRQ event detected. IRQ Acknowledge — This write-only bit is used to acknowledge interrupt request events (write 1 to clear IRQF). Writing 0 has no meaning or effect. Reads always return logic 0. If edge-and-level detection is selected (IRQMOD = 1), IRQF cannot be cleared while the IRQ pin remains at its asserted level. IRQ Interrupt Enable — This read/write control bit determines whether IRQ events generate a hardware interrupt request. 0 Hardware interrupt requests from IRQF disabled (use polling). 1 Hardware interrupt requested whenever IRQF = 1. IRQ Detection Mode — This read/write control bit selects either edge-only detection or edge-and-level detection. The IRQEDG control bit determines the polarity of edges and levels that are detected as interrupt request events. See Section 5.5.2.2, “Edge and Level Sensitivity” for more details. 0 IRQ event on falling edges or rising edges only. 1 IRQ event on falling edges and low levels or on rising edges and high levels. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 71 Chapter 5 Resets, Interrupts, and System Configuration 5.9.2 System Reset Status Register (SRS) This register includes seven read-only status flags to indicate the source of the most recent reset. When a debug host forces reset by writing 1 to BDFR in the SBDFR register, none of the status bits in SRS will be set. Writing any value to this register address clears the COP watchdog timer without affecting the contents of this register. The reset state of these bits depends on what caused the MCU to reset. R 7 6 5 4 3 2 1 0 POR PIN COP ILOP 0 ICG LVD 0 W Writing any value to SIMRS address clears COP watchdog timer. POR 1 0 0 0 0 0 1 0 LVR: U 0 0 0 0 0 1 0 Any other reset: 0 (1) (1) (1) 0 (1) 0 0 U = Unaffected by reset 1 Any of these reset sources that are active at the time of reset will cause the corresponding bit(s) to be set; bits corresponding to sources that are not active at the time of reset will be cleared. Figure 5-3. System Reset Status (SRS) Table 5-3. SRS Register Field Descriptions Field Description 7 POR Power-On Reset — Reset was caused by the power-on detection logic. Because the internal supply voltage was ramping up at the time, the low-voltage reset (LVR) status bit is also set to indicate that the reset occurred while the internal supply was below the LVR threshold. 0 Reset not caused by POR. 1 POR caused reset. 6 PIN External Reset Pin — Reset was caused by an active-low level on the external reset pin. 0 Reset not caused by external reset pin. 1 Reset came from external reset pin. 5 COP Computer Operating Properly (COP) Watchdog — Reset was caused by the COP watchdog timer timing out. This reset source may be blocked by COPE = 0. 0 Reset not caused by COP timeout. 1 Reset caused by COP timeout. 4 ILOP Illegal Opcode — Reset was caused by an attempt to execute an unimplemented or illegal opcode. The STOP instruction is considered illegal if stop is disabled by STOPE = 0 in the SOPT register. The BGND instruction is considered illegal if active background mode is disabled by ENBDM = 0 in the BDCSC register. 0 Reset not caused by an illegal opcode. 1 Reset caused by an illegal opcode. MC9S08AW60 Data Sheet, Rev.1.0 72 Freescale Semiconductor Chapter 5 Resets, Interrupts, and System Configuration Table 5-3. SRS Register Field Descriptions (continued) Field Description 2 ICG Internal Clock Generation Module Reset — Reset was caused by an ICG module reset. 0 Reset not caused by ICG module. 1 Reset caused by ICG module. 1 LVD Low Voltage Detect — If the LVDRE and LVDSE bits are set and the supply drops below the LVD trip voltage, an LVD reset will occur. This bit is also set by POR. 0 Reset not caused by LVD trip or POR. 1 Reset caused by LVD trip or POR. 5.9.3 System Background Debug Force Reset Register (SBDFR) This register contains a single write-only control bit. A serial background command such as WRITE_BYTE must be used to write to SBDFR. Attempts to write this register from a user program are ignored. Reads always return $00. R 7 6 5 4 3 2 1 0 0 0 0 0 0 0 0 0 BDFR1 W Reset 0 0 0 0 0 0 0 0 = Unimplemented or Reserved 1 BDFR is writable only through serial background debug commands, not from user programs. Figure 5-4. System Background Debug Force Reset Register (SBDFR) Table 5-4. SBDFR Register Field Descriptions Field Description 0 BDFR Background Debug Force Reset — A serial background command such as WRITE_BYTE may be used to allow an external debug host to force a target system reset. Writing logic 1 to this bit forces an MCU reset. This bit cannot be written from a user program. 5.9.4 System Options Register (SOPT) This register may be read at any time. Bits 3 and 2 are unimplemented and always read 0. This is a write-once register so only the first write after reset is honored. Any subsequent attempt to write to SOPT (intentionally or unintentionally) is ignored to avoid accidental changes to these sensitive settings. SOPT should be written during the user’s reset initialization program to set the desired controls even if the desired settings are the same as the reset settings. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 73 Chapter 5 Resets, Interrupts, and System Configuration 7 6 5 COPE COPT STOPE 1 1 0 4 R 3 2 0 0 0 0 1 0 1 1 W Reset 1 = Unimplemented or Reserved Figure 5-5. System Options Register (SOPT) Table 5-5. SOPT Register Field Descriptions Field Description 7 COPE COP Watchdog Enable — This write-once bit defaults to 1 after reset. 0 COP watchdog timer disabled. 1 COP watchdog timer enabled (force reset on timeout). 6 COPT COP Watchdog Timeout — This write-once bit defaults to 1 after reset. 0 Short timeout period selected (213 cycles of BUSCLK). 1 Long timeout period selected (218 cycles of BUSCLK). 5 STOPE Stop Mode Enable — This write-once bit defaults to 0 after reset, which disables stop mode. If stop mode is disabled and a user program attempts to execute a STOP instruction, an illegal opcode reset is forced. 0 Stop mode disabled. 1 Stop mode enabled. 5.9.5 System MCLK Control Register (SMCLK) This register is used to control the MCLK clock output. R 7 6 5 0 0 0 4 3 2 1 0 0 MPE MCSEL W Reset 0 0 0 0 0 0 0 0 = Unimplemented or Reserved Figure 5-6. System MCLK Control Register (SMCLK) Table 5-6. SMCLK Register Field Descriptions Field 4 MPE 2:0 MCSEL Description MCLK Pin Enable — This bit is used to enable the MCLK function. 0 MCLK output disabled. 1 MCLK output enabled on PTC2 pin. MCLK Divide Select — These bits are used to select the divide ratio for the MCLK output according to the formula below when the MCSEL bits are not equal to all zeroes. In the case that the MCSEL bits are all zero and MPE is set, the pin is driven low. See Equation 5-1. MCLK frequency = Bus Clock frequency ÷ (2 * MCSEL) Eqn. 5-1 MC9S08AW60 Data Sheet, Rev.1.0 74 Freescale Semiconductor Chapter 5 Resets, Interrupts, and System Configuration 5.9.6 System Device Identification Register (SDIDH, SDIDL) This read-only register is included so host development systems can identify the HCS08 derivative. This allows the development software to recognize where specific memory blocks, registers, and control bits are located in a target MCU. 7 6 5 4 R 3 2 1 0 ID11 ID10 ID9 ID8 0 0 0 0 W Reset — — — — = Unimplemented or Reserved Figure 5-7. System Device Identification Register — High (SDIDH) Table 5-7. SDIDH Register Field Descriptions Field 7:4 Reserved 3:0 ID[11:8] R Description Bits 7:4 are reserved. Reading these bits will result in an indeterminate value; writes have no effect. Part Identification Number — Each derivative in the HCS08 Family has a unique identification number. The MC9S08AW60/48/32/16 is hard coded to the value $008. See also ID bits in Table 5-8. 7 6 5 4 3 2 1 0 ID7 ID6 ID5 ID4 ID3 ID2 ID1 ID0 0 0 0 0 1 0 0 0 W Reset = Unimplemented or Reserved Figure 5-8. System Device Identification Register — Low (SDIDL) Table 5-8. SDIDL Register Field Descriptions Field 7:0 ID[7:0] Description Part Identification Number — Each derivative in the HCS08 Family has a unique identification number. The MC9S08AW60/48/32/16 is hard coded to the value $008. See also ID bits in Table 5-7. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 75 Chapter 5 Resets, Interrupts, and System Configuration 5.9.7 System Real-Time Interrupt Status and Control Register (SRTISC) This register contains one read-only status flag, one write-only acknowledge bit, three read/write delay selects, and three unimplemented bits, which always read 0. R 7 6 RTIF 0 W 5 4 RTICLKS RTIE 0 0 3 2 1 0 RTIS2 RTIS1 RTIS0 0 0 0 0 RTIACK Reset 0 0 0 = Unimplemented or Reserved Figure 5-9. System RTI Status and Control Register (SRTISC) Table 5-9. SRTISC Register Field Descriptions Field Description 7 RTIF Real-Time Interrupt Flag — This read-only status bit indicates the periodic wakeup timer has timed out. 0 Periodic wakeup timer not timed out. 1 Periodic wakeup timer timed out. 6 RTIACK Real-Time Interrupt Acknowledge — This write-only bit is used to acknowledge real-time interrupt request (write 1 to clear RTIF). Writing 0 has no meaning or effect. Reads always return logic 0. 5 RTICLKS Real-Time Interrupt Clock Select — This read/write bit selects the clock source for the real-time interrupt. 0 Real-time interrupt request clock source is internal 1-kHz oscillator. 1 Real-time interrupt request clock source is external clock. 4 RTIE Real-Time Interrupt Enable — This read-write bit enables real-time interrupts. 0 Real-time interrupts disabled. 1 Real-time interrupts enabled. 2:0 RTIS[2:0] Real-Time Interrupt Delay Selects — These read/write bits select the wakeup delay for the RTI. The clock source for the real-time interrupt is a self-clocked source which oscillates at about 1 kHz, is independent of other MCU clock sources. Using external clock source the delays will be crystal frequency divided by value in RTIS2:RTIS1:RTIS0. See Table 5-10. Table 5-10. Real-Time Interrupt Frequency 1 RTIS2:RTIS1:RTIS0 1-kHz Clock Source Delay1 Using External Clock Source Delay (Crystal Frequency) 0:0:0 Disable periodic wakeup timer Disable periodic wakeup timer 0:0:1 8 ms divide by 256 0:1:0 32 ms divide by 1024 0:1:1 64 ms divide by 2048 1:0:0 128 ms divide by 4096 1:0:1 256 ms divide by 8192 1:1:0 512 ms divide by 16384 1:1:1 1.024 s divide by 32768 Normal values are shown in this column based on fRTI = 1 kHz. See Appendix A, “Electrical Characteristics and Timing Specifications,” fRTI for the tolerance on these values. MC9S08AW60 Data Sheet, Rev.1.0 76 Freescale Semiconductor Chapter 5 Resets, Interrupts, and System Configuration 5.9.8 R System Power Management Status and Control 1 Register (SPMSC1) 7 6 LVDF 0 W Reset 5 4 3 2 LVDIE LVDRE(2) LVDSE(2) LVDE(2) 0 1 1 1 1 1 0 BGBE LVDACK 0 0 0 0 = Unimplemented or Reserved 1 2 Bit 1 is a reserved bit that must always be written to 0. This bit can be written only one time after reset. Additional writes are ignored. Figure 5-10. System Power Management Status and Control 1 Register (SPMSC1) Table 5-11. SPMSC1 Register Field Descriptions Field Description 7 LVDF Low-Voltage Detect Flag — Provided LVDE = 1, this read-only status bit indicates a low-voltage detect event. 6 LVDACK Low-Voltage Detect Acknowledge — This write-only bit is used to acknowledge low voltage detection errors (write 1 to clear LVDF). Reads always return 0. 5 LVDIE Low-Voltage Detect Interrupt Enable — This read/write bit enables hardware interrupt requests for LVDF. 0 Hardware interrupt disabled (use polling). 1 Request a hardware interrupt when LVDF = 1. 4 LVDRE Low-Voltage Detect Reset Enable — This read/write bit enables LVDF events to generate a hardware reset (provided LVDE = 1). 0 LVDF does not generate hardware resets. 1 Force an MCU reset when LVDF = 1. 3 LVDSE Low-Voltage Detect Stop Enable — Provided LVDE = 1, this read/write bit determines whether the low-voltage detect function operates when the MCU is in stop mode. 0 Low-voltage detect disabled during stop mode. 1 Low-voltage detect enabled during stop mode. 2 LVDE Low-Voltage Detect Enable — This read/write bit enables low-voltage detect logic and qualifies the operation of other bits in this register. 0 LVD logic disabled. 1 LVD logic enabled. 1 BGBE Bandgap Buffer Enable — The BGBE bit is used to enable an internal buffer for the bandgap voltage reference for use by the ADC module on one of its internal channels. 0 Bandgap buffer disabled. 1 Bandgap buffer enabled. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 77 Chapter 5 Resets, Interrupts, and System Configuration 5.9.9 System Power Management Status and Control 2 Register (SPMSC2) This register is used to report the status of the low voltage warning function, and to configure the stop mode behavior of the MCU. R 7 6 LVWF 0 W 5 4 LVDV LVWV 3 2 PPDF 0 LVWACK 1 0 PPDC1 PPDACK Power-on reset: 0(2) 0 0 0 0 0 0 0 LVD reset: 0(2) 0 U U 0 0 0 0 Any other reset: 0(2) 0 U U 0 0 0 0 = Unimplemented or Reserved 1 2 U = Unaffected by reset This bit can be written only one time after reset. Additional writes are ignored. LVWF will be set in the case when VSupply transitions below the trip point or after reset and VSupply is already below VLVW. Figure 5-11. System Power Management Status and Control 2 Register (SPMSC2) Table 5-12. SPMSC2 Register Field Descriptions Field 7 LVWF 6 LVWACK Description Low-Voltage Warning Flag — The LVWF bit indicates the low voltage warning status. 0 Low voltage warning not present. 1 Low voltage warning is present or was present. Low-Voltage Warning Acknowledge — The LVWACK bit is the low-voltage warning acknowledge. Writing a 1 to LVWACK clears LVWF to a 0 if a low voltage warning is not present. 5 LVDV Low-Voltage Detect Voltage Select — The LVDV bit selects the LVD trip point voltage (VLVD). 0 Low trip point selected (VLVD = VLVDL). 1 High trip point selected (VLVD = VLVDH). 4 LVWV Low-Voltage Warning Voltage Select — The LVWV bit selects the LVW trip point voltage (VLVW). 0 Low trip point selected (VLVW = VLVWL). 1 High trip point selected (VLVW = VLVWH). 3 PPDF Partial Power Down Flag — The PPDF bit indicates that the MCU has exited the stop2 mode. 0 Not stop2 mode recovery. 1 Stop2 mode recovery. 2 PPDACK 0 PPDC Partial Power Down Acknowledge — Writing a 1 to PPDACK clears the PPDF bit. Partial Power Down Control — The write-once PPDC bit controls whether stop2 or stop3 mode is selected. 0 Stop3 mode enabled. 1 Stop2, partial power down, mode enabled. MC9S08AW60 Data Sheet, Rev.1.0 78 Freescale Semiconductor Chapter 6 Parallel Input/Output 6.1 Introduction This chapter explains software controls related to parallel input/output (I/O). The MC9S08AW60 has seven I/O ports which include a total of 54 general-purpose I/O pins. See Chapter 2, “Pins and Connections” for more information about the logic and hardware aspects of these pins. Many of these pins are shared with on-chip peripherals such as timer systems, communication systems, or keyboard interrupts. When these other modules are not controlling the port pins, they revert to general-purpose I/O control. NOTE Not all general-purpose I/O pins are available on all packages. To avoid extra current drain from floating input pins, the user’s reset initialization routine in the application program should either enable on-chip pullup devices or change the direction of unconnected pins to outputs so the pins do not float. Table 6-1. KBI and Parallel I/O Interaction 1 PTxPEn (Pull Enable) PTxDDn (Data Direction) KBIPEn (KBI Pin Enable) KBEDGn (KBI Edge Select) Pullup Pulldown 0 0 0 x1 disabled disabled 1 0 0 x enabled disabled x 1 0 x disabled disabled 1 x 1 0 enabled disabled 1 x 1 1 disabled enabled 0 x 1 x disabled disabled x = Don’t care 6.2 Features Parallel I/O and Pin Control features, depending on package choice, include: • A total of 54 general-purpose I/O pins in seven ports • Hysteresis input buffers • Software-controlled pullups on each input pin MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 79 Chapter 6 Parallel Input/Output • • • • • • • • Software-controlled slew rate output buffers Eight port A pins Eight port B pins shared with ADC1 Seven port C pins shared with SCI2, IIC1, and MCLK Eight port D pins shared with ADC1, KBI1, and TPM1 and TPM2 external clock inputs Eight port E pins shared with SCI1, TPM1, and SPI1 Eight port F pins shared with TPM1 and TPM2 Seven port G pins shared with XTAL, EXTAL, and KBI1 6.3 Pin Descriptions The MC9S08AW60/48/32/16 has a total of 54 parallel I/O pins in seven ports (PTA–PTG). Not all pins are bonded out in all packages. Consult the pin assignment in Chapter 2, “Pins and Connections,” for available parallel I/O pins. All of these pins are available for general-purpose I/O when they are not used by other on-chip peripheral systems. After reset, the shared peripheral functions are disabled so that the pins are controlled by the parallel I/O. All of the parallel I/O are configured as inputs (PTxDDn = 0). The pin control functions for each pin are configured as follows: slew rate control enabled (PTxSEn = 1), low drive strength selected (PTxDSn = 0), and internal pullups disabled (PTxPEn = 0). The following paragraphs discuss each port and the software controls that determine each pin’s use. 6.3.1 Port A Port A MCU Pin: Bit 7 6 5 4 3 2 1 Bit 0 PTA7 PTA6 PTA5 PTA4 PTA3 PTA2 PTA1 PTA0 Figure 6-1. Port A Pin Names Port A pins are general-purpose I/O pins. Parallel I/O function is controlled by the port A data (PTAD) and data direction (PTADD) registers which are located in page zero register space. The pin control registers, pullup enable (PTAPE), slew rate control (PTASE), and drive strength select (PTADS) are located in the high page registers. Refer to Section 6.4, “Parallel I/O Control” for more information about general-purpose I/O control and Section 6.5, “Pin Control” for more information about pin control. 6.3.2 Port B Port B MCU Pin: Bit 7 6 5 4 3 2 1 Bit 0 PTB7/ AD1P7 PTB6/ AD1P6 PTB5/ AD1P5 PTB4/ AD1P4 PTB3/ AD1P3 PTB2/ AD1P2 PTB1/ AD1P1 PTB0/ AD1P0 Figure 6-2. Port B Pin Names MC9S08AW60 Data Sheet, Rev.1.0 80 Freescale Semiconductor Chapter 6 Parallel Input/Output Port B pins are general-purpose I/O pins. Parallel I/O function is controlled by the port B data (PTBD) and data direction (PTBDD) registers which are located in page zero register space. The pin control registers, pullup enable (PTBPE), slew rate control (PTBSE), and drive strength select (PTBDS) are located in the high page registers. Refer to Section 6.4, “Parallel I/O Control” for more information about general-purpose I/O control and Section 6.5, “Pin Control” for more information about pin control. Port B general-purpose I/O are shared with the ADC. Any pin enabled as an ADC input will have the general-purpose I/O function disabled. Refer to Chapter 14, “Analog-to-Digital Converter (S08ADC10V1)” for more information about using port B as analog inputs. 6.3.3 Port C Port C Bit 7 MCU Pin: 6 5 3 3 2 1 Bit 0 PTC6 PTC5/ RxD2 PTC4 PTC3/ TxD2 PTC2/ MCLK PTC1/ SDA1 PTC0/ SCL1 Figure 6-3. Port C Pin Names Port C pins are general-purpose I/O pins. Parallel I/O function is controlled by the port C data (PTCD) and data direction (PTCDD) registers which are located in page zero register space. The pin control registers, pullup enable (PTCPE), slew rate control (PTCSE), and drive strength select (PTCDS) are located in the high page registers. Refer to Section 6.4, “Parallel I/O Control” for more information about general-purpose I/O control and Section 6.5, “Pin Control” for more information about pin control. Port C general-purpose I/O is shared with SCI2, IIC, and MCLK. When any of these shared functions is enabled, the direction, input or output, is controlled by the shared function and not by the data direction register of the parallel I/O port. Also, for pins which are configured as outputs by the shared function, the output data is controlled by the shared function and not by the port data register. Refer to Chapter 11, “Serial Communications Interface (S08SCIV2)” for more information about using port C pins as SCI pins. Refer to Chapter 13, “Inter-Integrated Circuit (S08IICV1)” for more information about using port C pins as IIC pins. Refer to Chapter 5, “Resets, Interrupts, and System Configuration” for more information about using PTC2 as the MCLK pin. 6.3.4 Port D Port D Bit 7 6 5 4 3 2 1 Bit 0 PTD7/ PTD6/ AD1P14/ TPM1CLK PTD5/ AD1P13/ PTD4/ AD1P12/ TPM2CLK PTD3/ AD1P11/ KBI1P6 PTD2/ AD1P10/ KBI1P5 PTD1/ AD1P9 PTD0/ AD1P8 MCU Pin: AD1P15/ KBI1P7 Figure 6-4. Port D Pin Names Port D pins are general-purpose I/O pins. Parallel I/O function is controlled by the port D data (PTDD) and data direction (PTDDD) registers which are located in page zero register space. The pin control registers, MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 81 Chapter 6 Parallel Input/Output pullup enable (PTDPE), slew rate control (PTDSE), and drive strength select (PTDDS) are located in the high page registers. Refer to Section 6.4, “Parallel I/O Control” for more information about general-purpose I/O control and Section 6.5, “Pin Control” for more information about pin control. Port D general-purpose I/O are shared with the ADC, KBI, and TPM1 and TPM2 external clock inputs. When any of these shared functions is enabled, the direction, input or output, is controlled by the shared function and not by the data direction register of the parallel I/O port. When a pin is shared with both the ADC and a digital peripheral function, the ADC has higher priority. For example, in the case that both the ADC and the KBI are configured to use PTD7 then the pin is controlled by the ADC module. Refer to Chapter 10, “Timer/PWM (S08TPMV2)” for more information about using port D pins as TPM external clock inputs. Refer to Chapter 14, “Analog-to-Digital Converter (S08ADC10V1)” for more information about using port D pins as analog inputs. Refer to Chapter 9, “Keyboard Interrupt (S08KBIV1)” for more information about using port D pins as keyboard inputs. 6.3.5 Port E Port E MCU Pin: Bit 7 6 5 4 PTE7/ SPSCK1 PTE6/ MOSI1 PTE5/ MISO1 PTE4/ SS1 3 2 PTE3/ PTE2/ TPM1CH1 TPM1CH0 1 Bit 0 PTE1/ RxD1 PTE0/ TxD1 Figure 6-5. Port E Pin Names Port E pins are general-purpose I/O pins. Parallel I/O function is controlled by the port E data (PTED) and data direction (PTEDD) registers which are located in page zero register space. The pin control registers, pullup enable (PTEPE), slew rate control (PTESE), and drive strength select (PTEDS) are located in the high page registers. Refer to Section 6.4, “Parallel I/O Control” for more information about general-purpose I/O control and Section 6.5, “Pin Control” for more information about pin control. Port E general-purpose I/O is shared with SCI1, SPI, and TPM1 timer channels. When any of these shared functions is enabled, the direction, input or output, is controlled by the shared function and not by the data direction register of the parallel I/O port. Also, for pins which are configured as outputs by the shared function, the output data is controlled by the shared function and not by the port data register. Refer to Chapter 11, “Serial Communications Interface (S08SCIV2)” for more information about using port E pins as SCI pins. Refer to Chapter 12, “Serial Peripheral Interface (S08SPIV3)” for more information about using port E pins as SPI pins. Refer to Chapter 10, “Timer/PWM (S08TPMV2)” for more information about using port E pins as TPM channel pins. MC9S08AW60 Data Sheet, Rev.1.0 82 Freescale Semiconductor Chapter 6 Parallel Input/Output 6.3.6 Port F Port F MCU Pin: Bit 7 6 5 PTF7 PTF6 4 3 2 1 Bit 0 PTF5/ PTF4/ PTF3/ PTF2/ PTF1/ PTF0/ TPM2CH1 TPM2CH0 TPM1CH5 TPM1CH4 TPM1CH3 TPM1CH2 Figure 6-6. Port F Pin Names Port F pins are general-purpose I/O pins. Parallel I/O function is controlled by the port F data (PTFD) and data direction (PTFDD) registers which are located in page zero register space. The pin control registers, pullup enable (PTFPE), slew rate control (PTFSE), and drive strength select (PTFDS) are located in the high page registers. Refer to Section 6.4, “Parallel I/O Control” for more information about general-purpose I/O control and Section 6.5, “Pin Control” for more information about pin control. Port F general-purpose I/O is shared with TPM1 and TPM2 timer channels. When any of these shared functions is enabled, the direction, input or output, is controlled by the shared function and not by the data direction register of the parallel I/O port. Also, for pins which are configured as outputs by the shared function, the output data is controlled by the shared function and not by the port data register. Refer to Chapter 10, “Timer/PWM (S08TPMV2)” for more information about using port F pins as TPM channel pins. 6.3.7 Port G Port G Bit 7 MCU Pin: 6 5 4 3 2 1 Bit 0 PTG6/ EXTAL PTG5/ XTAL PTG4/ KBI1P4 PTG3/ KBI1P3 PTG2/ KBI1P2 PTG1/ KBI1P1 PTG0/ KBI1P0 Figure 6-7. Port G Pin Names Port G pins are general-purpose I/O pins. Parallel I/O function is controlled by the port G data (PTGD) and data direction (PTGDD) registers which are located in page zero register space. The pin control registers, pullup enable (PTGPE), slew rate control (PTGSE), and drive strength select (PTGDS) are located in the high page registers. Refer to Section 6.4, “Parallel I/O Control” for more information about general-purpose I/O control and Section 6.5, “Pin Control” for more information about pin control. Port G general-purpose I/O is shared with KBI, XTAL, and EXTAL. When a pin is enabled as a KBI input, the pin functions as an input regardless of the state of the associated PTG data direction register bit. When the external oscillator is enabled, PTG5 and PTG6 function as oscillator pins. In this case the associated parallel I/O and pin control registers have no control of the pins. Refer to Chapter 8, “Internal Clock Generator (S08ICGV4)” for more information about using port G pins as XTAL and EXTAL pins. Refer to Chapter 9, “Keyboard Interrupt (S08KBIV1)” for more information about using port G pins as keyboard inputs. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 83 Chapter 6 Parallel Input/Output 6.4 Parallel I/O Control Reading and writing of parallel I/O is done through the port data registers. The direction, input or output, is controlled through the port data direction registers. The parallel I/O port function for an individual pin is illustrated in the block diagram below. PTxDDn D Output Enable Q PTxDn D Output Data Q 1 Port Read Data 0 Synchronizer Input Data BUSCLK Figure 6-8. Parallel I/O Block Diagram The data direction control bits determine whether the pin output driver is enabled, and they control what is read for port data register reads. Each port pin has a data direction register bit. When PTxDDn = 0, the corresponding pin is an input and reads of PTxD return the pin value. When PTxDDn = 1, the corresponding pin is an output and reads of PTxD return the last value written to the port data register. When a peripheral module or system function is in control of a port pin, the data direction register bit still controls what is returned for reads of the port data register, even though the peripheral system has overriding control of the actual pin direction. When a shared analog function is enabled for a pin, all digital pin functions are disabled. A read of the port data register returns a value of 0 for any bits which have shared analog functions enabled. In general, whenever a pin is shared with both an alternate digital function and an analog function, the analog function has priority such that if both the digital and analog functions are enabled, the analog function controls the pin. It is a good programming practice to write to the port data register before changing the direction of a port pin to become an output. This ensures that the pin will not be driven momentarily with an old data value that happened to be in the port data register. MC9S08AW60 Data Sheet, Rev.1.0 84 Freescale Semiconductor Chapter 6 Parallel Input/Output 6.5 Pin Control The pin control registers are located in the high page register block of the memory. These registers are used to control pullups, slew rate, and drive strength for the I/O pins. The pin control registers operate independently of the parallel I/O registers. 6.5.1 Internal Pullup Enable An internal pullup device can be enabled for each port pin by setting the corresponding bit in one of the pullup enable registers (PTxPEn). The pullup device is disabled if the pin is configured as an output by the parallel I/O control logic or any shared peripheral function regardless of the state of the corresponding pullup enable register bit. The pullup device is also disabled if the pin is controlled by an analog function. 6.5.2 Output Slew Rate Control Enable Slew rate control can be enabled for each port pin by setting the corresponding bit in one of the slew rate control registers (PTxSEn). When enabled, slew control limits the rate at which an output can transition in order to reduce EMC emissions. Slew rate control has no effect on pins which are configured as inputs. 6.5.3 Output Drive Strength Select An output pin can be selected to have high output drive strength by setting the corresponding bit in one of the drive strength select registers (PTxDSn). When high drive is selected a pin is capable of sourcing and sinking greater current. Even though every I/O pin can be selected as high drive, the user must ensure that the total current source and sink limits for the chip are not exceeded. Drive strength selection is intended to affect the DC behavior of I/O pins. However, the AC behavior is also affected. High drive allows a pin to drive a greater load with the same switching speed as a low drive enabled pin into a smaller load. Because of this the EMC emissions may be affected by enabling pins as high drive. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 85 Chapter 6 Parallel Input/Output 6.6 Pin Behavior in Stop Modes Depending on the stop mode, I/O functions differently as the result of executing a STOP instruction. An explanation of I/O behavior for the various stop modes follows: • Stop2 mode is a partial power-down mode, whereby I/O latches are maintained in their state as before the STOP instruction was executed. CPU register status and the state of I/O registers should be saved in RAM before the STOP instruction is executed to place the MCU in stop2 mode. Upon recovery from stop2 mode, before accessing any I/O, the user should examine the state of the PPDF bit in the SPMSC2 register. If the PPDF bit is 0, I/O must be initialized as if a power on reset had occurred. If the PPDF bit is 1, I/O data previously stored in RAM, before the STOP instruction was executed, peripherals may require being initialized and restored to their pre-stop condition. The user must then write a 1 to the PPDACK bit in the SPMSC2 register. Access to I/O is now permitted again in the user’s application program. • In stop3 mode, all I/O is maintained because internal logic circuity stays powered up. Upon recovery, normal I/O function is available to the user. 6.7 Parallel I/O and Pin Control Registers This section provides information about the registers associated with the parallel I/O ports and pin control functions. These parallel I/O registers are located in page zero of the memory map and the pin control registers are located in the high page register section of memory. Refer to tables in Chapter 4, “Memory,” for the absolute address assignments for all parallel I/O and pin control registers. This section refers to registers and control bits only by their names. A Freescale-provided equate or header file normally is used to translate these names into the appropriate absolute addresses. 6.7.1 Port A I/O Registers (PTAD and PTADD) Port A parallel I/O function is controlled by the registers listed below. 7 6 5 4 3 2 1 0 PTAD7 PTAD6 PTAD5 PTAD4 PTAD3 PTAD2 PTAD1 PTAD0 0 0 0 0 0 0 0 0 R W Reset Figure 6-9. Port A Data Register (PTAD) Table 6-2. PTAD Register Field Descriptions Field Description 7:0 PTAD[7:0] Port A Data Register Bits — For port A pins that are inputs, reads return the logic level on the pin. For port A pins that are configured as outputs, reads return the last value written to this register. Writes are latched into all bits of this register. For port A pins that are configured as outputs, the logic level is driven out the corresponding MCU pin. Reset forces PTAD to all 0s, but these 0s are not driven out the corresponding pins because reset also configures all port pins as high-impedance inputs with pullups disabled. MC9S08AW60 Data Sheet, Rev.1.0 86 Freescale Semiconductor Chapter 6 Parallel Input/Output 7 6 5 4 3 2 1 0 PTADD7 PTADD6 PTADD5 PTADD4 PTADD3 PTADD2 PTADD1 PTADD0 0 0 0 0 0 0 0 0 R W Reset Figure 6-10. Data Direction for Port A Register (PTADD) Table 6-3. PTADD Register Field Descriptions Field Description 7:0 Data Direction for Port A Bits — These read/write bits control the direction of port A pins and what is read for PTADD[7:0] PTAD reads. 0 Input (output driver disabled) and reads return the pin value. 1 Output driver enabled for port A bit n and PTAD reads return the contents of PTADn. 6.7.2 Port A Pin Control Registers (PTAPE, PTASE, PTADS) In addition to the I/O control, port A pins are controlled by the registers listed below. 7 6 5 4 3 2 1 0 PTAPE7 PTAPE6 PTAPE5 PTAPE4 PTAPE3 PTAPE2 PTAPE1 PTAPE0 0 0 0 0 0 0 0 0 R W Reset Figure 6-11. Internal Pullup Enable for Port A (PTAPE) Table 6-4. PTADD Register Field Descriptions Field Description [7:0] Internal Pullup Enable for Port A Bits — Each of these control bits determines if the internal pullup device is PTAPE[7:0] enabled for the associated PTA pin. For port A pins that are configured as outputs, these bits have no effect and the internal pullup devices are disabled. 0 Internal pullup device disabled for port A bit n. 1 Internal pullup device enabled for port A bit n. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 87 Chapter 6 Parallel Input/Output 7 6 5 4 3 2 1 0 PTASE7 PTASE6 PTASE5 PTASE4 PTASE3 PTASE2 PTASE1 PTASE0 1 1 1 1 1 1 1 1 R W Reset Figure 6-12. Output Slew Rate Control Enable for Port A (PTASE) Table 6-5. PTASE Register Field Descriptions Field Description 7:0 Output Slew Rate Control Enable for Port A Bits — Each of these control bits determine whether output slew PTASE[7:0] rate control is enabled for the associated PTA pin. For port A pins that are configured as inputs, these bits have no effect. 0 Output slew rate control disabled for port A bit n. 1 Output slew rate control enabled for port A bit n. 7 6 5 4 3 2 1 0 PTADS7 PTADS6 PTADS5 PTADS4 PTADS3 PTADS2 PTADS1 PTADS0 0 0 0 0 0 0 0 0 R W Reset Figure 6-13. Output Drive Strength Selection for Port A (PTASE) Table 6-6. PTASE Register Field Descriptions Field Description 7:0 Output Drive Strength Selection for Port A Bits — Each of these control bits selects between low and high PTADS[7:0] output drive for the associated PTA pin. 0 Low output drive enabled for port A bit n. 1 High output drive enabled for port A bit n. MC9S08AW60 Data Sheet, Rev.1.0 88 Freescale Semiconductor Chapter 6 Parallel Input/Output 6.7.3 Port B I/O Registers (PTBD and PTBDD) Port B parallel I/O function is controlled by the registers listed below. 7 6 5 4 3 2 1 0 PTBD7 PTBD6 PTBD5 PTBD4 PTBD3 PTBD2 PTBD1 PTBD0 0 0 0 0 0 0 0 0 R W Reset Figure 6-14. Port B Data Register (PTBD) Table 6-7. PTBD Register Field Descriptions Field Description 7:0 PTBD[7:0] Port B Data Register Bits — For port B pins that are inputs, reads return the logic level on the pin. For port B pins that are configured as outputs, reads return the last value written to this register. Writes are latched into all bits of this register. For port B pins that are configured as outputs, the logic level is driven out the corresponding MCU pin. Reset forces PTBD to all 0s, but these 0s are not driven out the corresponding pins because reset also configures all port pins as high-impedance inputs with pullups disabled. 7 6 5 4 3 2 1 0 PTBDD7 PTBDD6 PTBDD5 PTBDD4 PTBDD3 PTBDD2 PTBDD1 PTBDD0 0 0 0 0 0 0 0 0 R W Reset Figure 6-15. Data Direction for Port B (PTBDD) Table 6-8. PTBDD Register Field Descriptions Field Description 7:0 Data Direction for Port B Bits — These read/write bits control the direction of port B pins and what is read for PTBDD[7:0] PTBD reads. 0 Input (output driver disabled) and reads return the pin value. 1 Output driver enabled for port B bit n and PTBD reads return the contents of PTBDn. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 89 Chapter 6 Parallel Input/Output 6.7.4 Port B Pin Control Registers (PTBPE, PTBSE, PTBDS) In addition to the I/O control, port B pins are controlled by the registers listed below. 7 6 5 4 3 2 1 0 PTBPE7 PTBPE6 PTBPE5 PTBPE4 PTBPE3 PTBPE2 PTBPE1 PTBPE0 0 0 0 0 0 0 0 0 R W Reset Figure 6-16. Internal Pullup Enable for Port B (PTBPE) Table 6-9. PTBPE Register Field Descriptions Field Description 7:0 Internal Pullup Enable for Port B Bits — Each of these control bits determines if the internal pullup device is PTBPE[7:0] enabled for the associated PTB pin. For port B pins that are configured as outputs, these bits have no effect and the internal pullup devices are disabled. 0 Internal pullup device disabled for port B bit n. 1 Internal pullup device enabled for port B bit n. 7 6 5 4 3 2 1 0 PTBSE7 PTBSE6 PTBSE5 PTBSE4 PTBSE3 PTBSE2 PTBSE1 PTBSE0 1 1 1 1 1 1 1 1 R W Reset Figure 6-17. Output Slew Rate Control Enable (PTBSE) Table 6-10. PTBSE Register Field Descriptions Field Description 7:0 Output Slew Rate Control Enable for Port B Bits— Each of these control bits determine whether output slew PTBSE[7:0] rate control is enabled for the associated PTB pin. For port B pins that are configured as inputs, these bits have no effect. 0 Output slew rate control disabled for port B bit n. 1 Output slew rate control enabled for port B bit n. MC9S08AW60 Data Sheet, Rev.1.0 90 Freescale Semiconductor Chapter 6 Parallel Input/Output 7 6 5 4 3 2 1 0 PTBDS7 PTBDS6 PTBDS5 PTBDS4 PTBDS3 PTBDS2 PTBDS1 PTBDS0 0 0 0 0 0 0 0 0 R W Reset Figure 6-18. Output Drive Strength Selection for Port B (PTBDS) Table 6-11. PTBDS Register Field Descriptions Field Description 7:0 Output Drive Strength Selection for Port B Bits — Each of these control bits selects between low and high PTBDS[7:0] output drive for the associated PTB pin. 0 Low output drive enabled for port B bit n. 1 High output drive enabled for port B bit n. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 91 Chapter 6 Parallel Input/Output 6.7.5 Port C I/O Registers (PTCD and PTCDD) Port C parallel I/O function is controlled by the registers listed below. 7 6 5 4 3 2 1 0 PTCD6 PTCD5 PTCD4 PTCD3 PTCD2 PTCD1 PTCD0 0 0 0 0 0 0 0 R W Reset 0 Figure 6-19. Port C Data Register (PTCD) Table 6-12. PTCD Register Field Descriptions Field Description 6:0 PTCD[6:0] Port C Data Register Bits — For port C pins that are inputs, reads return the logic level on the pin. For port C pins that are configured as outputs, reads return the last value written to this register. Writes are latched into all bits of this register. For port C pins that are configured as outputs, the logic level is driven out the corresponding MCU pin. Reset forces PTCD to all 0s, but these 0s are not driven out the corresponding pins because reset also configures all port pins as high-impedance inputs with pullups disabled. 7 6 5 4 3 2 1 0 PTCDD6 PTCDD5 PTCDD4 PTCDD3 PTCDD2 PTCDD1 PTCDD0 0 0 0 0 0 0 0 R W Reset 0 Figure 6-20. Data Direction for Port C (PTCDD) Table 6-13. PTCDD Register Field Descriptions Field Description 6:0 Data Direction for Port C Bits — These read/write bits control the direction of port C pins and what is read for PTCDD[6:0] PTCD reads. 0 Input (output driver disabled) and reads return the pin value. 1 Output driver enabled for port C bit n and PTCD reads return the contents of PTCDn. MC9S08AW60 Data Sheet, Rev.1.0 92 Freescale Semiconductor Chapter 6 Parallel Input/Output 6.7.6 Port C Pin Control Registers (PTCPE, PTCSE, PTCDS) In addition to the I/O control, port C pins are controlled by the registers listed below. 7 6 5 4 3 2 1 0 PTCPE6 PTCPE5 PTCPE4 PTCPE3 PTCPE2 PTCPE1 PTCPE0 0 0 0 0 0 0 0 R W Reset 0 Figure 6-21. Internal Pullup Enable for Port C (PTCPE) Table 6-14. PTCPE Register Field Descriptions Field Description 6:0 Internal Pullup Enable for Port C Bits — Each of these control bits determines if the internal pullup device is PTCPE[6:0] enabled for the associated PTC pin. For port C pins that are configured as outputs, these bits have no effect and the internal pullup devices are disabled. 0 Internal pullup device disabled for port C bit n. 1 Internal pullup device enabled for port C bit n. 7 6 5 4 3 2 1 0 PTCSE6 PTCSE5 PTCSE4 PTCSE3 PTCSE2 PTCSE1 PTCSE0 1 1 1 1 1 1 1 R W Reset 0 Figure 6-22. Output Slew Rate Control Enable for Port C (PTCSE) Table 6-15. PTCSE Register Field Descriptions Field Description 6:0 Output Slew Rate Control Enable for Port C Bits — Each of these control bits determine whether output slew PTCSE[6:0] rate control is enabled for the associated PTC pin. For port C pins that are configured as inputs, these bits have no effect. 0 Output slew rate control disabled for port C bit n. 1 Output slew rate control enabled for port C bit n. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 93 Chapter 6 Parallel Input/Output 7 6 5 4 3 2 1 0 PTCDS6 PTCDS5 PTCDS4 PTCDS3 PTCDS2 PTCDS1 PTCDS0 0 0 0 0 0 0 0 R W Reset 0 Figure 6-23. Output Drive Strength Selection for Port C (PTCDS) Table 6-16. PTCDS Register Field Descriptions Field Description 6:0 Output Drive Strength Selection for Port C Bits — Each of these control bits selects between low and high PTCDS[6:0] output drive for the associated PTC pin. 0 Low output drive enabled for port C bit n. 1 High output drive enabled for port C bit n. MC9S08AW60 Data Sheet, Rev.1.0 94 Freescale Semiconductor Chapter 6 Parallel Input/Output 6.7.7 Port D I/O Registers (PTDD and PTDDD) Port D parallel I/O function is controlled by the registers listed below. 7 6 5 4 3 2 1 0 PTDD7 PTDD6 PTDD5 PTDD4 PTDD3 PTDD2 PTDD1 PTDD0 0 0 0 0 0 0 0 0 R W Reset Figure 6-24. Port D Data Register (PTDD) Table 6-17. PTDD Register Field Descriptions Field Description 7:0 PTDD[7:0] Port D Data Register Bits — For port D pins that are inputs, reads return the logic level on the pin. For port D pins that are configured as outputs, reads return the last value written to this register. Writes are latched into all bits of this register. For port D pins that are configured as outputs, the logic level is driven out the corresponding MCU pin. Reset forces PTDD to all 0s, but these 0s are not driven out the corresponding pins because reset also configures all port pins as high-impedance inputs with pullups disabled. 7 6 5 4 3 2 1 0 PTDDD7 PTDDD6 PTDDD5 PTDDD4 PTDDD3 PTDDD2 PTDDD1 PTDDD0 0 0 0 0 0 0 0 0 R W Reset Figure 6-25. Data Direction for Port D (PTDDD) Table 6-18. PTDDD Register Field Descriptions Field Description 7:0 Data Direction for Port D Bits — These read/write bits control the direction of port D pins and what is read for PTDDD[7:0] PTDD reads. 0 Input (output driver disabled) and reads return the pin value. 1 Output driver enabled for port D bit n and PTDD reads return the contents of PTDDn. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 95 Chapter 6 Parallel Input/Output 6.7.8 Port D Pin Control Registers (PTDPE, PTDSE, PTDDS) In addition to the I/O control, port D pins are controlled by the registers listed below. 7 6 5 4 3 2 1 0 PTDPE7 PTDPE6 PTDPE5 PTDPE4 PTDPE3 PTDPE2 PTDPE1 PTDPE0 0 0 0 0 0 0 0 0 R W Reset Figure 6-26. Internal Pullup Enable for Port D (PTDPE) Table 6-19. PTDPE Register Field Descriptions Field Description 7:0 Internal Pullup Enable for Port D Bits — Each of these control bits determines if the internal pullup device is PTDPE[7:0] enabled for the associated PTD pin. For port D pins that are configured as outputs, these bits have no effect and the internal pullup devices are disabled. 0 Internal pullup device disabled for port D bit n. 1 Internal pullup device enabled for port D bit n. 7 6 5 4 3 2 1 0 PTDSE7 PTDSE6 PTDSE5 PTDSE4 PTDSE3 PTDSE2 PTDSE1 PTDSE0 1 1 1 1 1 1 1 1 R W Reset Figure 6-27. Output Slew Rate Control Enable for Port D (PTDSE) Table 6-20. PTDSE Register Field Descriptions Field Description 7:0 Output Slew Rate Control Enable for Port D Bits — Each of these control bits determine whether output slew PTDSE[7:0] rate control is enabled for the associated PTD pin. For port D pins that are configured as inputs, these bits have no effect. 0 Output slew rate control disabled for port D bit n. 1 Output slew rate control enabled for port D bit n. MC9S08AW60 Data Sheet, Rev.1.0 96 Freescale Semiconductor Chapter 6 Parallel Input/Output 7 6 5 4 3 2 1 0 PTDDS7 PTDDS6 PTDDS5 PTDDS4 PTDDS3 PTDDS2 PTDDS1 PTDDS0 0 0 0 0 0 0 0 0 R W Reset Figure 6-28. Output Drive Strength Selection for Port D (PTDDS) Table 6-21. PTDDS Register Field Descriptions Field Description 7:0 Output Drive Strength Selection for Port D Bits — Each of these control bits selects between low and high PTDDS[7:0] output drive for the associated PTD pin. 0 Low output drive enabled for port D bit n. 1 High output drive enabled for port D bit n. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 97 Chapter 6 Parallel Input/Output 6.7.9 Port E I/O Registers (PTED and PTEDD) Port E parallel I/O function is controlled by the registers listed below. 7 6 5 4 3 2 1 0 PTED7 PTED6 PTED5 PTED4 PTED3 PTED2 PTED1 PTED0 0 0 0 0 0 0 0 0 R W Reset Figure 6-29. Port E Data Register (PTED) Table 6-22. PTED Register Field Descriptions Field Description 7:0 PTED[7:0] Port E Data Register Bits — For port E pins that are inputs, reads return the logic level on the pin. For port E pins that are configured as outputs, reads return the last value written to this register. Writes are latched into all bits of this register. For port E pins that are configured as outputs, the logic level is driven out the corresponding MCU pin. Reset forces PTED to all 0s, but these 0s are not driven out the corresponding pins because reset also configures all port pins as high-impedance inputs with pullups disabled. 7 6 5 4 3 2 1 0 PTEDD7 PTEDD6 PTEDD5 PTEDD4 PTEDD3 PTEDD2 PTEDD1 PTEDD0 0 0 0 0 0 0 0 0 R W Reset Figure 6-30. Data Direction for Port E (PTEDD) Table 6-23. PTEDD Register Field Descriptions Field Description 7:0 Data Direction for Port E Bits — These read/write bits control the direction of port E pins and what is read for PTEDD[7:0] PTED reads. 0 Input (output driver disabled) and reads return the pin value. 1 Output driver enabled for port E bit n and PTED reads return the contents of PTEDn. MC9S08AW60 Data Sheet, Rev.1.0 98 Freescale Semiconductor Chapter 6 Parallel Input/Output 6.7.10 Port E Pin Control Registers (PTEPE, PTESE, PTEDS) In addition to the I/O control, port E pins are controlled by the registers listed below. 7 6 5 4 3 2 1 0 PTEPE7 PTEPE6 PTEPE5 PTEPE4 PTEPE3 PTEPE2 PTEPE1 PTEPE0 0 0 0 0 0 0 0 0 R W Reset Figure 6-31. Internal Pullup Enable for Port E (PTEPE) Table 6-24. PTEPE Register Field Descriptions Field Description 7:0 Internal Pullup Enable for Port E Bits— Each of these control bits determines if the internal pullup device is PTEPE[7:0] enabled for the associated PTE pin. For port E pins that are configured as outputs, these bits have no effect and the internal pullup devices are disabled. 0 Internal pullup device disabled for port E bit n. 1 Internal pullup device enabled for port E bit n. 7 6 5 4 3 2 1 0 PTESE7 PTESE6 PTESE5 PTESE4 PTESE3 PTESE2 PTESE1 PTESE0 1 1 1 1 1 1 1 1 R W Reset Figure 6-32. Output Slew Rate Control Enable for Port E (PTESE) Table 6-25. PTESE Register Field Descriptions Field Description 7:0 Output Slew Rate Control Enable for Port E Bits — Each of these control bits determine whether output slew PTESE[7:0] rate control is enabled for the associated PTE pin. For port E pins that are configured as inputs, these bits have no effect. 0 Output slew rate control disabled for port E bit n. 1 Output slew rate control enabled for port E bit n. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 99 Chapter 6 Parallel Input/Output 7 6 5 4 3 2 1 0 PTEDS7 PTEDS6 PTEDS5 PTEDS4 PTEDS3 PTEDS2 PTEDS1 PTEDS0 0 0 0 0 0 0 0 0 R W Reset Figure 6-33. Output Drive Strength Selection for Port E (PTEDS) Table 6-26. PTEDS Register Field Descriptions Field Description 7:0 Output Drive Strength Selection for Port E Bits — Each of these control bits selects between low and high PTEDS[7:0] output drive for the associated PTE pin. 0 Low output drive enabled for port E bit n. 1 High output drive enabled for port E bit n. MC9S08AW60 Data Sheet, Rev.1.0 100 Freescale Semiconductor Chapter 6 Parallel Input/Output 6.7.11 Port F I/O Registers (PTFD and PTFDD) Port F parallel I/O function is controlled by the registers listed below. 7 6 5 4 3 2 1 0 PTFD7 PTFD6 PTFD5 PTFD4 PTFD3 PTFD2 PTFD1 PTFD0 0 0 0 0 0 0 0 0 R W Reset Figure 6-34. Port F Data Register (PTFD) Table 6-27. PTFD Register Field Descriptions Field Description 7:0 PTFD[7:0] Port F Data Register Bits— For port F pins that are inputs, reads return the logic level on the pin. For port F pins that are configured as outputs, reads return the last value written to this register. Writes are latched into all bits of this register. For port F pins that are configured as outputs, the logic level is driven out the corresponding MCU pin. Reset forces PTFD to all 0s, but these 0s are not driven out the corresponding pins because reset also configures all port pins as high-impedance inputs with pullups disabled. 7 6 5 4 3 2 1 0 PTFDD7 PTFDD6 PTFDD5 PTFDD4 PTFDD3 PTFDD2 PTFDD1 PTFDD0 0 0 0 0 0 0 0 0 R W Reset Figure 6-35. Data Direction for Port F (PTFDD) Table 6-28. PTFDD Register Field Descriptions Field Description 7:0 Data Direction for Port F Bits — These read/write bits control the direction of port F pins and what is read for PTFDD[7:0] PTFD reads. 0 Input (output driver disabled) and reads return the pin value. 1 Output driver enabled for port F bit n and PTFD reads return the contents of PTFDn. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 101 Chapter 6 Parallel Input/Output 6.7.12 Port F Pin Control Registers (PTFPE, PTFSE, PTFDS) In addition to the I/O control, port F pins are controlled by the registers listed below. 7 6 5 4 3 2 1 0 PTFPE7 PTFPE6 PTFPE5 PTFPE4 PTFPE3 PTFPE2 PTFPE1 PTFPE0 0 0 0 0 0 0 0 0 R W Reset Figure 6-36. Internal Pullup Enable for Port F (PTFPE) Table 6-29. PTFPE Register Field Descriptions Field Description 7:0 Internal Pullup Enable for Port F Bits — Each of these control bits determines if the internal pullup device is PTFPE[7:0] enabled for the associated PTF pin. For port F pins that are configured as outputs, these bits have no effect and the internal pullup devices are disabled. 0 Internal pullup device disabled for port F bit n. 1 Internal pullup device enabled for port F bit n. 7 6 5 4 3 2 1 0 PTFSE7 PTFSE6 PTFSE5 PTFSE4 PTFSE3 PTFSE2 PTFSE1 PTFSE0 1 1 1 1 1 1 1 1 R W Reset Figure 6-37. Output Slew Rate Control Enable for Port F (PTFSE) Table 6-30. PTFSE Register Field Descriptions Field Description 7:0 Output Slew Rate Control Enable for Port F Bits — Each of these control bits determine whether output slew PTFSE[7:0] rate control is enabled for the associated PTF pin. For port F pins that are configured as inputs, these bits have no effect. 0 Output slew rate control disabled for port F bit n. 1 Output slew rate control enabled for port F bit n. MC9S08AW60 Data Sheet, Rev.1.0 102 Freescale Semiconductor Chapter 6 Parallel Input/Output 7 6 5 4 3 2 1 0 PTFDS7 PTFDS6 PTFDS5 PTFDS4 PTFDS3 PTFDS2 PTFDS1 PTFDS0 0 0 0 0 0 0 0 0 R W Reset Figure 6-38. Output Drive Strength Selection for Port F (PTFDS) Table 6-31. PTFDS Register Field Descriptions Field Description 7:0 Output Drive Strength Selection for Port F Bits — Each of these control bits selects between low and high PTFDS[7:0] output drive for the associated PTF pin. 0 Low output drive enabled for port F bit n. 1 High output drive enabled for port F bit n. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 103 Chapter 6 Parallel Input/Output 6.7.13 Port G I/O Registers (PTGD and PTGDD) Port G parallel I/O function is controlled by the registers listed below. 7 6 5 4 3 2 1 0 PTGD6 PTGD5 PTGD4 PTGD3 PTGD2 PTGD1 PTGD0 0 0 0 0 0 0 0 R W Reset 0 Figure 6-39. Port G Data Register (PTGD) Table 6-32. PTGD Register Field Descriptions Field Description 6:0 PTGD[6:0] Port G Data Register Bits — For port G pins that are inputs, reads return the logic level on the pin. For port G pins that are configured as outputs, reads return the last value written to this register. Writes are latched into all bits of this register. For port G pins that are configured as outputs, the logic level is driven out the corresponding MCU pin. Reset forces PTGD to all 0s, but these 0s are not driven out the corresponding pins because reset also configures all port pins as high-impedance inputs with pullups disabled. 7 6 5 4 3 2 1 0 PTGDD6 PTGDD5 PTGDD4 PTGDD3 PTGDD2 PTGDD1 PTGDD0 0 0 0 0 0 0 0 R W Reset 0 Figure 6-40. Data Direction for Port G (PTGDD) Table 6-33. PTGDD Register Field Descriptions Field Description 6:0 Data Direction for Port G Bits — These read/write bits control the direction of port G pins and what is read for PTGDD[6:0] PTGD reads. 0 Input (output driver disabled) and reads return the pin value. 1 Output driver enabled for port G bit n and PTGD reads return the contents of PTGDn. MC9S08AW60 Data Sheet, Rev.1.0 104 Freescale Semiconductor Chapter 6 Parallel Input/Output 6.7.14 Port G Pin Control Registers (PTGPE, PTGSE, PTGDS) In addition to the I/O control, port G pins are controlled by the registers listed below. 7 6 5 4 3 2 1 0 PTGPE6 PTGPE5 PTGPE4 PTGPE3 PTGPE2 PTGPE1 PTGPE0 0 0 0 0 0 0 0 R W Reset 0 Figure 6-41. Internal Pullup Enable for Port G Bits (PTGPE) Table 6-34. PTGPE Register Field Descriptions Field Description 6:0 Internal Pullup Enable for Port G Bits — Each of these control bits determines if the internal pullup device is PTGPE[6:0] enabled for the associated PTG pin. For port G pins that are configured as outputs, these bits have no effect and the internal pullup devices are disabled. 0 Internal pullup device disabled for port G bit n. 1 Internal pullup device enabled for port G bit n. 7 6 5 4 3 2 1 0 PTGSE6 PTGSE5 PTGSE4 PTGSE3 PTGSE2 PTGSE1 PTGSE0 1 1 1 1 1 1 1 R W Reset 0 Figure 6-42. Output Slew Rate Control Enable for Port G Bits (PTGSE) Table 6-35. PTGSE Register Field Descriptions Field Description 6:0 Output Slew Rate Control Enable for Port G Bits— Each of these control bits determine whether output slew PTGSE[6:0] rate control is enabled for the associated PTG pin. For port G pins that are configured as inputs, these bits have no effect. 0 Output slew rate control disabled for port G bit n. 1 Output slew rate control enabled for port G bit n. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 105 Chapter 6 Parallel Input/Output 7 6 5 4 3 2 1 0 PTGDS6 PTGDS5 PTGDS4 PTGDS3 PTGDS2 PTGDS1 PTGDS0 0 0 0 0 0 0 0 R W Reset 0 Figure 6-43. Output Drive Strength Selection for Port G (PTGDS) Table 6-36. PTGDS Register Field Descriptions Field Description 6:0 Output Drive Strength Selection for Port G Bits — Each of these control bits selects between low and high PTGDS[6:0] output drive for the associated PTG pin. 0 Low output drive enabled for port G bit n. 1 High output drive enabled for port G bit n. MC9S08AW60 Data Sheet, Rev.1.0 106 Freescale Semiconductor Chapter 7 Central Processor Unit (S08CPUV2) 7.1 Introduction This section provides summary information about the registers, addressing modes, and instruction set of the CPU of the HCS08 Family. For a more detailed discussion, refer to the HCS08 Family Reference Manual, volume 1, Freescale Semiconductor document order number HCS08RMV1/D. The HCS08 CPU is fully source- and object-code-compatible with the M68HC08 CPU. Several instructions and enhanced addressing modes were added to improve C compiler efficiency and to support a new background debug system which replaces the monitor mode of earlier M68HC08 microcontrollers (MCU). 7.1.1 Features Features of the HCS08 CPU include: • Object code fully upward-compatible with M68HC05 and M68HC08 Families • All registers and memory are mapped to a single 64-Kbyte address space • 16-bit stack pointer (any size stack anywhere in 64-Kbyte address space) • 16-bit index register (H:X) with powerful indexed addressing modes • 8-bit accumulator (A) • Many instructions treat X as a second general-purpose 8-bit register • Seven addressing modes: — Inherent — Operands in internal registers — Relative — 8-bit signed offset to branch destination — Immediate — Operand in next object code byte(s) — Direct — Operand in memory at 0x0000–0x00FF — Extended — Operand anywhere in 64-Kbyte address space — Indexed relative to H:X — Five submodes including auto increment — Indexed relative to SP — Improves C efficiency dramatically • Memory-to-memory data move instructions with four address mode combinations • Overflow, half-carry, negative, zero, and carry condition codes support conditional branching on the results of signed, unsigned, and binary-coded decimal (BCD) operations • Efficient bit manipulation instructions • Fast 8-bit by 8-bit multiply and 16-bit by 8-bit divide instructions • STOP and WAIT instructions to invoke low-power operating modes MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 107 Chapter 7 Central Processor Unit (S08CPUV2) 7.2 Programmer’s Model and CPU Registers Figure 7-1 shows the five CPU registers. CPU registers are not part of the memory map. 7 0 ACCUMULATOR A 16-BIT INDEX REGISTER H:X H INDEX REGISTER (HIGH) 8 15 INDEX REGISTER (LOW) 7 X 0 SP STACK POINTER 0 15 PROGRAM COUNTER 7 0 CONDITION CODE REGISTER V 1 1 H I N Z C PC CCR CARRY ZERO NEGATIVE INTERRUPT MASK HALF-CARRY (FROM BIT 3) TWO’S COMPLEMENT OVERFLOW Figure 7-1. CPU Registers 7.2.1 Accumulator (A) The A accumulator is a general-purpose 8-bit register. One operand input to the arithmetic logic unit (ALU) is connected to the accumulator and the ALU results are often stored into the A accumulator after arithmetic and logical operations. The accumulator can be loaded from memory using various addressing modes to specify the address where the loaded data comes from, or the contents of A can be stored to memory using various addressing modes to specify the address where data from A will be stored. Reset has no effect on the contents of the A accumulator. 7.2.2 Index Register (H:X) This 16-bit register is actually two separate 8-bit registers (H and X), which often work together as a 16-bit address pointer where H holds the upper byte of an address and X holds the lower byte of the address. All indexed addressing mode instructions use the full 16-bit value in H:X as an index reference pointer; however, for compatibility with the earlier M68HC05 Family, some instructions operate only on the low-order 8-bit half (X). Many instructions treat X as a second general-purpose 8-bit register that can be used to hold 8-bit data values. X can be cleared, incremented, decremented, complemented, negated, shifted, or rotated. Transfer instructions allow data to be transferred from A or transferred to A where arithmetic and logical operations can then be performed. For compatibility with the earlier M68HC05 Family, H is forced to 0x00 during reset. Reset has no effect on the contents of X. MC9S08AW60 Data Sheet, Rev.1.0 108 Freescale Semiconductor Chapter 7 Central Processor Unit (S08CPUV2) 7.2.3 Stack Pointer (SP) This 16-bit address pointer register points at the next available location on the automatic last-in-first-out (LIFO) stack. The stack may be located anywhere in the 64-Kbyte address space that has RAM and can be any size up to the amount of available RAM. The stack is used to automatically save the return address for subroutine calls, the return address and CPU registers during interrupts, and for local variables. The AIS (add immediate to stack pointer) instruction adds an 8-bit signed immediate value to SP. This is most often used to allocate or deallocate space for local variables on the stack. SP is forced to 0x00FF at reset for compatibility with the earlier M68HC05 Family. HCS08 programs normally change the value in SP to the address of the last location (highest address) in on-chip RAM during reset initialization to free up direct page RAM (from the end of the on-chip registers to 0x00FF). The RSP (reset stack pointer) instruction was included for compatibility with the M68HC05 Family and is seldom used in new HCS08 programs because it only affects the low-order half of the stack pointer. 7.2.4 Program Counter (PC) The program counter is a 16-bit register that contains the address of the next instruction or operand to be fetched. During normal program execution, the program counter automatically increments to the next sequential memory location every time an instruction or operand is fetched. Jump, branch, interrupt, and return operations load the program counter with an address other than that of the next sequential location. This is called a change-of-flow. During reset, the program counter is loaded with the reset vector that is located at $FFFE and $FFFF. The vector stored there is the address of the first instruction that will be executed after exiting the reset state. 7.2.5 Condition Code Register (CCR) The 8-bit condition code register contains the interrupt mask (I) and five flags that indicate the results of the instruction just executed. Bits 6 and 5 are set permanently to 1. The following paragraphs describe the functions of the condition code bits in general terms. For a more detailed explanation of how each instruction sets the CCR bits, refer to the HCS08 Family Reference Manual, volume 1, Freescale Semiconductor document order number HCS08RMv1/D. 7 0 CONDITION CODE REGISTER V 1 1 H I N Z C CCR CARRY ZERO NEGATIVE INTERRUPT MASK HALF-CARRY (FROM BIT 3) TWO’S COMPLEMENT OVERFLOW Figure 7-2. Condition Code Register MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 109 Chapter 7 Central Processor Unit (S08CPUV2) Table 7-1. CCR Register Field Descriptions Field Description 7 V Two’s Complement Overflow Flag — The CPU sets the overflow flag when a two’s complement overflow occurs. The signed branch instructions BGT, BGE, BLE, and BLT use the overflow flag. 0 No overflow 1 Overflow 4 H Half-Carry Flag — The CPU sets the half-carry flag when a carry occurs between accumulator bits 3 and 4 during an add-without-carry (ADD) or add-with-carry (ADC) operation. The half-carry flag is required for binary-coded decimal (BCD) arithmetic operations. The DAA instruction uses the states of the H and C condition code bits to automatically add a correction value to the result from a previous ADD or ADC on BCD operands to correct the result to a valid BCD value. 0 No carry between bits 3 and 4 1 Carry between bits 3 and 4 3 I Interrupt Mask Bit — When the interrupt mask is set, all maskable CPU interrupts are disabled. CPU interrupts are enabled when the interrupt mask is cleared. When a CPU interrupt occurs, the interrupt mask is set automatically after the CPU registers are saved on the stack, but before the first instruction of the interrupt service routine is executed. Interrupts are not recognized at the instruction boundary after any instruction that clears I (CLI or TAP). This ensures that the next instruction after a CLI or TAP will always be executed without the possibility of an intervening interrupt, provided I was set. 0 Interrupts enabled 1 Interrupts disabled 2 N Negative Flag — The CPU sets the negative flag when an arithmetic operation, logic operation, or data manipulation produces a negative result, setting bit 7 of the result. Simply loading or storing an 8-bit or 16-bit value causes N to be set if the most significant bit of the loaded or stored value was 1. 0 Non-negative result 1 Negative result 1 Z Zero Flag — The CPU sets the zero flag when an arithmetic operation, logic operation, or data manipulation produces a result of 0x00 or 0x0000. Simply loading or storing an 8-bit or 16-bit value causes Z to be set if the loaded or stored value was all 0s. 0 Non-zero result 1 Zero result 0 C Carry/Borrow Flag — The CPU sets the carry/borrow flag when an addition operation produces a carry out of bit 7 of the accumulator or when a subtraction operation requires a borrow. Some instructions — such as bit test and branch, shift, and rotate — also clear or set the carry/borrow flag. 0 No carry out of bit 7 1 Carry out of bit 7 7.3 Addressing Modes Addressing modes define the way the CPU accesses operands and data. In the HCS08, all memory, status and control registers, and input/output (I/O) ports share a single 64-Kbyte linear address space so a 16-bit binary address can uniquely identify any memory location. This arrangement means that the same instructions that access variables in RAM can also be used to access I/O and control registers or nonvolatile program space. Some instructions use more than one addressing mode. For instance, move instructions use one addressing mode to specify the source operand and a second addressing mode to specify the destination address. Instructions such as BRCLR, BRSET, CBEQ, and DBNZ use one addressing mode to specify the location MC9S08AW60 Data Sheet, Rev.1.0 110 Freescale Semiconductor Chapter 7 Central Processor Unit (S08CPUV2) of an operand for a test and then use relative addressing mode to specify the branch destination address when the tested condition is true. For BRCLR, BRSET, CBEQ, and DBNZ, the addressing mode listed in the instruction set tables is the addressing mode needed to access the operand to be tested, and relative addressing mode is implied for the branch destination. 7.3.1 Inherent Addressing Mode (INH) In this addressing mode, operands needed to complete the instruction (if any) are located within CPU registers so the CPU does not need to access memory to get any operands. 7.3.2 Relative Addressing Mode (REL) Relative addressing mode is used to specify the destination location for branch instructions. A signed 8-bit offset value is located in the memory location immediately following the opcode. During execution, if the branch condition is true, the signed offset is sign-extended to a 16-bit value and is added to the current contents of the program counter, which causes program execution to continue at the branch destination address. 7.3.3 Immediate Addressing Mode (IMM) In immediate addressing mode, the operand needed to complete the instruction is included in the object code immediately following the instruction opcode in memory. In the case of a 16-bit immediate operand, the high-order byte is located in the next memory location after the opcode, and the low-order byte is located in the next memory location after that. 7.3.4 Direct Addressing Mode (DIR) In direct addressing mode, the instruction includes the low-order eight bits of an address in the direct page (0x0000–0x00FF). During execution a 16-bit address is formed by concatenating an implied 0x00 for the high-order half of the address and the direct address from the instruction to get the 16-bit address where the desired operand is located. This is faster and more memory efficient than specifying a complete 16-bit address for the operand. 7.3.5 Extended Addressing Mode (EXT) In extended addressing mode, the full 16-bit address of the operand is located in the next two bytes of program memory after the opcode (high byte first). 7.3.6 Indexed Addressing Mode Indexed addressing mode has seven variations including five that use the 16-bit H:X index register pair and two that use the stack pointer as the base reference. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 111 Chapter 7 Central Processor Unit (S08CPUV2) 7.3.6.1 Indexed, No Offset (IX) This variation of indexed addressing uses the 16-bit value in the H:X index register pair as the address of the operand needed to complete the instruction. 7.3.6.2 Indexed, No Offset with Post Increment (IX+) This variation of indexed addressing uses the 16-bit value in the H:X index register pair as the address of the operand needed to complete the instruction. The index register pair is then incremented (H:X = H:X + 0x0001) after the operand has been fetched. This addressing mode is only used for MOV and CBEQ instructions. 7.3.6.3 Indexed, 8-Bit Offset (IX1) This variation of indexed addressing uses the 16-bit value in the H:X index register pair plus an unsigned 8-bit offset included in the instruction as the address of the operand needed to complete the instruction. 7.3.6.4 Indexed, 8-Bit Offset with Post Increment (IX1+) This variation of indexed addressing uses the 16-bit value in the H:X index register pair plus an unsigned 8-bit offset included in the instruction as the address of the operand needed to complete the instruction. The index register pair is then incremented (H:X = H:X + 0x0001) after the operand has been fetched. This addressing mode is used only for the CBEQ instruction. 7.3.6.5 Indexed, 16-Bit Offset (IX2) This variation of indexed addressing uses the 16-bit value in the H:X index register pair plus a 16-bit offset included in the instruction as the address of the operand needed to complete the instruction. 7.3.6.6 SP-Relative, 8-Bit Offset (SP1) This variation of indexed addressing uses the 16-bit value in the stack pointer (SP) plus an unsigned 8-bit offset included in the instruction as the address of the operand needed to complete the instruction. 7.3.6.7 SP-Relative, 16-Bit Offset (SP2) This variation of indexed addressing uses the 16-bit value in the stack pointer (SP) plus a 16-bit offset included in the instruction as the address of the operand needed to complete the instruction. 7.4 Special Operations The CPU performs a few special operations that are similar to instructions but do not have opcodes like other CPU instructions. In addition, a few instructions such as STOP and WAIT directly affect other MCU circuitry. This section provides additional information about these operations. MC9S08AW60 Data Sheet, Rev.1.0 112 Freescale Semiconductor Chapter 7 Central Processor Unit (S08CPUV2) 7.4.1 Reset Sequence Reset can be caused by a power-on-reset (POR) event, internal conditions such as the COP (computer operating properly) watchdog, or by assertion of an external active-low reset pin. When a reset event occurs, the CPU immediately stops whatever it is doing (the MCU does not wait for an instruction boundary before responding to a reset event). For a more detailed discussion about how the MCU recognizes resets and determines the source, refer to the Resets, Interrupts, and System Configuration chapter. The reset event is considered concluded when the sequence to determine whether the reset came from an internal source is done and when the reset pin is no longer asserted. At the conclusion of a reset event, the CPU performs a 6-cycle sequence to fetch the reset vector from 0xFFFE and 0xFFFF and to fill the instruction queue in preparation for execution of the first program instruction. 7.4.2 Interrupt Sequence When an interrupt is requested, the CPU completes the current instruction before responding to the interrupt. At this point, the program counter is pointing at the start of the next instruction, which is where the CPU should return after servicing the interrupt. The CPU responds to an interrupt by performing the same sequence of operations as for a software interrupt (SWI) instruction, except the address used for the vector fetch is determined by the highest priority interrupt that is pending when the interrupt sequence started. The CPU sequence for an interrupt is: 1. Store the contents of PCL, PCH, X, A, and CCR on the stack, in that order. 2. Set the I bit in the CCR. 3. Fetch the high-order half of the interrupt vector. 4. Fetch the low-order half of the interrupt vector. 5. Delay for one free bus cycle. 6. Fetch three bytes of program information starting at the address indicated by the interrupt vector to fill the instruction queue in preparation for execution of the first instruction in the interrupt service routine. After the CCR contents are pushed onto the stack, the I bit in the CCR is set to prevent other interrupts while in the interrupt service routine. Although it is possible to clear the I bit with an instruction in the interrupt service routine, this would allow nesting of interrupts (which is not recommended because it leads to programs that are difficult to debug and maintain). For compatibility with the earlier M68HC05 MCUs, the high-order half of the H:X index register pair (H) is not saved on the stack as part of the interrupt sequence. The user must use a PSHH instruction at the beginning of the service routine to save H and then use a PULH instruction just before the RTI that ends the interrupt service routine. It is not necessary to save H if you are certain that the interrupt service routine does not use any instructions or auto-increment addressing modes that might change the value of H. The software interrupt (SWI) instruction is like a hardware interrupt except that it is not masked by the global I bit in the CCR and it is associated with an instruction opcode within the program so it is not asynchronous to program execution. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 113 Chapter 7 Central Processor Unit (S08CPUV2) 7.4.3 Wait Mode Operation The WAIT instruction enables interrupts by clearing the I bit in the CCR. It then halts the clocks to the CPU to reduce overall power consumption while the CPU is waiting for the interrupt or reset event that will wake the CPU from wait mode. When an interrupt or reset event occurs, the CPU clocks will resume and the interrupt or reset event will be processed normally. If a serial BACKGROUND command is issued to the MCU through the background debug interface while the CPU is in wait mode, CPU clocks will resume and the CPU will enter active background mode where other serial background commands can be processed. This ensures that a host development system can still gain access to a target MCU even if it is in wait mode. 7.4.4 Stop Mode Operation Usually, all system clocks, including the crystal oscillator (when used), are halted during stop mode to minimize power consumption. In such systems, external circuitry is needed to control the time spent in stop mode and to issue a signal to wake up the target MCU when it is time to resume processing. Unlike the earlier M68HC05 and M68HC08 MCUs, the HCS08 can be configured to keep a minimum set of clocks running in stop mode. This optionally allows an internal periodic signal to wake the target MCU from stop mode. When a host debug system is connected to the background debug pin (BKGD) and the ENBDM control bit has been set by a serial command through the background interface (or because the MCU was reset into active background mode), the oscillator is forced to remain active when the MCU enters stop mode. In this case, if a serial BACKGROUND command is issued to the MCU through the background debug interface while the CPU is in stop mode, CPU clocks will resume and the CPU will enter active background mode where other serial background commands can be processed. This ensures that a host development system can still gain access to a target MCU even if it is in stop mode. Recovery from stop mode depends on the particular HCS08 and whether the oscillator was stopped in stop mode. Refer to the Modes of Operation chapter for more details. 7.4.5 BGND Instruction The BGND instruction is new to the HCS08 compared to the M68HC08. BGND would not be used in normal user programs because it forces the CPU to stop processing user instructions and enter the active background mode. The only way to resume execution of the user program is through reset or by a host debug system issuing a GO, TRACE1, or TAGGO serial command through the background debug interface. Software-based breakpoints can be set by replacing an opcode at the desired breakpoint address with the BGND opcode. When the program reaches this breakpoint address, the CPU is forced to active background mode rather than continuing the user program. MC9S08AW60 Data Sheet, Rev.1.0 114 Freescale Semiconductor Chapter 7 Central Processor Unit (S08CPUV2) 7.5 HCS08 Instruction Set Summary Instruction Set Summary Nomenclature The nomenclature listed here is used in the instruction descriptions in Table 7-2. Operators () ← & | ⊕ × ÷ : + – = = = = = = = = = = CPU registers A = CCR = H = X = PC = PCH = PCL = SP = Contents of register or memory location shown inside parentheses Is loaded with (read: “gets”) Boolean AND Boolean OR Boolean exclusive-OR Multiply Divide Concatenate Add Negate (two’s complement) Accumulator Condition code register Index register, higher order (most significant) 8 bits Index register, lower order (least significant) 8 bits Program counter Program counter, higher order (most significant) 8 bits Program counter, lower order (least significant) 8 bits Stack pointer Memory and addressing M = A memory location or absolute data, depending on addressing mode M:M + 0x0001= A 16-bit value in two consecutive memory locations. The higher-order (most significant) 8 bits are located at the address of M, and the lower-order (least significant) 8 bits are located at the next higher sequential address. Condition code register (CCR) bits V = Two’s complement overflow indicator, bit 7 H = Half carry, bit 4 I = Interrupt mask, bit 3 N = Negative indicator, bit 2 Z = Zero indicator, bit 1 C = Carry/borrow, bit 0 (carry out of bit 7) CCR activity notation – = Bit not affected MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 115 Chapter 7 Central Processor Unit (S08CPUV2) 0 1 U = = = = Bit forced to 0 Bit forced to 1 Bit set or cleared according to results of operation Undefined after the operation Machine coding notation dd = Low-order 8 bits of a direct address 0x0000–0x00FF (high byte assumed to be 0x00) ee = Upper 8 bits of 16-bit offset ff = Lower 8 bits of 16-bit offset or 8-bit offset ii = One byte of immediate data jj = High-order byte of a 16-bit immediate data value kk = Low-order byte of a 16-bit immediate data value hh = High-order byte of 16-bit extended address ll = Low-order byte of 16-bit extended address rr = Relative offset Source form Everything in the source forms columns, except expressions in italic characters, is literal information that must appear in the assembly source file exactly as shown. The initial 3- to 5-letter mnemonic is always a literal expression. All commas, pound signs (#), parentheses, and plus signs (+) are literal characters. n — Any label or expression that evaluates to a single integer in the range 0–7 opr8i — Any label or expression that evaluates to an 8-bit immediate value opr16i — Any label or expression that evaluates to a 16-bit immediate value opr8a — Any label or expression that evaluates to an 8-bit value. The instruction treats this 8-bit value as the low order 8 bits of an address in the direct page of the 64-Kbyte address space (0x00xx). opr16a — Any label or expression that evaluates to a 16-bit value. The instruction treats this value as an address in the 64-Kbyte address space. oprx8 — Any label or expression that evaluates to an unsigned 8-bit value, used for indexed addressing oprx16 — Any label or expression that evaluates to a 16-bit value. Because the HCS08 has a 16-bit address bus, this can be either a signed or an unsigned value. rel — Any label or expression that refers to an address that is within –128 to +127 locations from the next address after the last byte of object code for the current instruction. The assembler will calculate the 8-bit signed offset and include it in the object code for this instruction. Address modes INH = IMM = DIR = EXT = Inherent (no operands) 8-bit or 16-bit immediate 8-bit direct 16-bit extended MC9S08AW60 Data Sheet, Rev.1.0 116 Freescale Semiconductor Chapter 7 Central Processor Unit (S08CPUV2) IX IX+ IX1 IX1+ = = = = IX2 REL SP1 SP2 = = = = 16-bit indexed no offset 16-bit indexed no offset, post increment (CBEQ and MOV only) 16-bit indexed with 8-bit offset from H:X 16-bit indexed with 8-bit offset, post increment (CBEQ only) 16-bit indexed with 16-bit offset from H:X 8-bit relative offset Stack pointer with 8-bit offset Stack pointer with 16-bit offset V H I N Z C ADC ADC ADC ADC ADC ADC ADC ADC ADD ADD ADD ADD ADD ADD ADD ADD #opr8i opr8a opr16a oprx16,X oprx8,X ,X oprx16,SP oprx8,SP #opr8i opr8a opr16a oprx16,X oprx8,X ,X oprx16,SP oprx8,SP AIS #opr8i AIX #opr8i AND #opr8i AND opr8a AND opr16a AND oprx16,X AND oprx8,X AND ,X AND oprx16,SP AND oprx8,SP ASL opr8a ASLA ASLX ASL oprx8,X ASL ,X ASL oprx8,SP ASR opr8a ASRA ASRX ASR oprx8,X ASR ,X ASR oprx8,SP BCC rel A ← (A) + (M) + (C) Add with Carry A ← (A) + (M) Add without Carry Add Immediate Value (Signed) to Stack Pointer Add Immediate Value (Signed) to Index Register (H:X) ii dd hh ll ee ff ff ee ff ff ii dd hh ll ee ff ff ee ff ff 2 3 4 4 3 3 5 4 2 3 4 4 3 3 5 4 – – – – – – IMM A7 ii 2 H:X ← (H:X) + (M) M is sign extended to a 16-bit value – – – – – – IMM AF ii 2 A ← (A) & (M) C 0 – – – – 0 b7 b0 C Arithmetic Shift Right b7 Branch if Carry Bit Clear – A9 B9 C9 D9 E9 F9 9ED9 9EE9 AB BB CB DB EB FB 9EDB 9EEB SP ← (SP) + (M) M is sign extended to a 16-bit value Logical AND Arithmetic Shift Left (Same as LSL) – IMM DIR EXT IX2 IX1 IX SP2 SP1 IMM DIR EXT IX2 IX1 IX SP2 SP1 Bus Cycles1 Description Operand Operation Opcode Effect on CCR Source Form Address Mode Table 7-2. HCS08 Instruction Set Summary (Sheet 1 of 7) – – b0 Branch if (C) = 0 – – – IMM DIR EXT – IX2 IX1 IX SP2 SP1 DIR INH INH IX1 IX SP1 DIR INH INH IX1 IX SP1 – – – REL A4 B4 C4 D4 E4 F4 9ED4 9EE4 38 48 58 68 78 9E68 37 47 57 67 77 9E67 24 ii dd hh ll ee ff ff ee ff ff dd ff ff dd ff ff rr 2 3 4 4 3 3 5 4 5 1 1 5 4 6 5 1 1 5 4 6 3 MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 117 Chapter 7 Central Processor Unit (S08CPUV2) Description V H I N Z C – – – – – – DIR (b0) BCLR n,opr8a Clear Bit n in Memory Mn ← 0 BCS rel Branch if Carry Bit Set (Same as BLO) Branch if (C) = 1 BEQ rel Branch if Equal Branch if (Z) = 1 BGE rel Branch if Greater Than or Equal To (Signed Operands) Branch if (N ⊕ V) = 0 BGND Enter Active Background if ENBDM = 1 Waits For and Processes BDM Commands Until GO, TRACE1, or TAGGO BGT rel BHCS rel Branch if Greater Than (Signed Operands) Branch if Half Carry Bit Clear Branch if Half Carry Bit Set BHI rel Branch if Higher BHS rel Branch if Higher or Same (Same as BCC) BIH rel Branch if IRQ Pin High Branch if IRQ pin = 1 BIL rel Branch if IRQ Pin Low Branch if IRQ pin = 0 BHCC rel BIT BIT BIT BIT BIT BIT BIT BIT #opr8i opr8a opr16a oprx16,X oprx8,X ,X oprx16,SP oprx8,SP Bit Test DIR (b1) DIR (b2) DIR (b3) DIR (b4) DIR (b5) DIR (b6) DIR (b7) – – – – – – REL 27 rr 3 REL 90 rr 3 INH 82 5+ Branch if (Z) | (N ⊕ V) = 0 – – – – – – REL 92 rr 3 Branch if (H) = 0 – – – – – – REL 28 rr 3 Branch if (H) = 1 – – – – – – REL 29 rr 3 22 rr 3 24 rr 3 2F rr 3 Branch if (C) | (Z) = 0 Branch if (C) = 0 – – – – – – REL – – – – – – REL – – – – – – REL – – – – – – REL IMM 0 – – DIR EXT – IX2 IX1 IX SP2 SP1 (A) & (M) (CCR Updated but Operands Not Changed) – – – – – BLO rel BLS rel Branch if Lower or Same Branch if (C) | (Z) = 1 BLT rel Branch if Less Than (Signed Operands) Branch if Interrupt Mask Clear Branch if (N ⊕ V ) = 1 – – – – – – REL – – – – – – REL Branch if (I) = 0 – – – – – – REL BMC rel 5 5 5 5 5 5 5 5 3 Branch if Less Than or Equal To (Signed Operands) Branch if Lower (Same as BCS) BLE rel dd dd dd dd dd dd dd dd 25 rr – – – – – – REL – – – – – – – – – – – – 11 13 15 17 19 1B 1D 1F Bus Cycles1 Operation Operand Effect on CCR Opcode Source Form Address Mode Table 7-2. HCS08 Instruction Set Summary (Sheet 2 of 7) Branch if (Z) | (N ⊕ V) = 1 Branch if (C) = 1 BMI rel Branch if Minus Branch if (N) = 1 BMS rel Branch if Interrupt Mask Set Branch if (I) = 1 BNE rel Branch if Not Equal Branch if (Z) = 0 BPL rel Branch if Plus Branch if (N) = 0 BRA rel Branch Always No Test 2E rr A5 B5 C5 D5 E5 F5 9ED5 9EE5 ii dd hh ll ee ff ff ee ff ff 3 2 3 4 4 3 3 5 4 – REL 93 rr 3 – – – – – – REL 25 rr 3 23 rr 3 91 rr 3 2C rr 3 2B rr 3 2D rr 3 26 rr 3 – – – – – – REL – – – – – – REL – – – – – – REL – – – – – – REL – – – – – – REL 2A rr 3 20 rr 3 MC9S08AW60 Data Sheet, Rev.1.0 118 Freescale Semiconductor Chapter 7 Central Processor Unit (S08CPUV2) V H I N Z C – – – – – BRCLR n,opr8a,rel Branch if Bit n in Memory Clear Branch if (Mn) = 0 BRN rel Branch Never Uses 3 Bus Cycles BRSET n,opr8a,rel Branch if Bit n in Memory Set DIR (b0) DIR (b1) DIR (b2) DIR (b3) DIR (b4) DIR (b5) DIR (b6) DIR (b7) – – – – – – REL DIR (b0) – – – – – Set Bit n in Memory BSR rel Branch to Subroutine Mn ← 1 PC ← (PC) + 0x0002 push (PCL); SP ← (SP) – 0x0001 push (PCH); SP ← (SP) – 0x0001 PC ← (PC) + rel Branch if (A) = (M) Branch if (A) = (M) Branch if (X) = (M) Branch if (A) = (M) Branch if (A) = (M) Branch if (A) = (M) CBEQ opr8a,rel CBEQA #opr8i,rel CBEQX #opr8i,rel CBEQ oprx8,X+,rel CBEQ ,X+,rel CBEQ oprx8,SP,rel Compare and Branch if Equal CLC Clear Carry Bit C←0 CLI Clear Interrupt Mask Bit I←0 CLR opr8a CLRA CLRX CLRH CLR oprx8,X CLR ,X CLR oprx8,SP CMP #opr8i CMP opr8a CMP opr16a CMP oprx16,X CMP oprx8,X CMP ,X CMP oprx16,SP CMP oprx8,SP COM opr8a COMA COMX COM oprx8,X COM ,X COM oprx8,SP CPHX opr16a CPHX #opr16i CPHX opr8a CPHX oprx8,SP Clear M ← 0x00 A ← 0x00 X ← 0x00 H ← 0x00 M ← 0x00 M ← 0x00 M ← 0x00 DIR (b1) DIR (b2) DIR (b3) DIR (b4) DIR (b5) DIR (b6) DIR (b7) 10 12 14 16 18 1A 1C 1E dd dd dd dd dd dd dd dd REL AD rr – – – – – – DIR 31 41 51 61 71 9E61 – – – – – 0 INH – – 0 – – – INH 0 – – 0 1 – DIR 98 IMM IMM IX1+ IX+ SP1 Complement (One’s Complement) Compare Index Register (H:X) with Memory (A) – (M) (CCR Updated But Operands Not Changed) M ← (M)= 0xFF – (M) A ← (A) = 0xFF – (A) X ← (X) = 0xFF – (X) M ← (M) = 0xFF – (M) M ← (M) = 0xFF – (M) M ← (M) = 0xFF – (M) 5 5 5 5 5 5 5 5 3 rr rr rr rr rr rr rr rr 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 – – – – – – – – Compare Accumulator with Memory rr rr rr rr rr rr rr rr 21 rr dd dd dd dd dd dd dd dd – – – – – – DIR (b0) BSET n,opr8a dd dd dd dd dd dd dd dd 00 02 04 06 08 0A 0C 0E DIR (b1) DIR (b2) DIR (b3) DIR (b4) DIR (b5) DIR (b6) DIR (b7) Branch if (Mn) = 1 01 03 05 07 09 0B 0D 0F Bus Cycles1 Description Operand Operation Opcode Effect on CCR Source Form Address Mode Table 7-2. HCS08 Instruction Set Summary (Sheet 3 of 7) 0 – – (H:X) – (M:M + 0x0001) (CCR Updated But Operands Not Changed) – – INH INH INH IX1 IX SP1 IMM DIR EXT IX2 IX1 IX SP2 SP1 1 DIR INH INH IX1 IX SP1 EXT IMM DIR SP1 dd ii ii ff rr ff 5 rr rr rr rr rr 1 9A 3F 4F 5F 8C 6F 7F 9E6F A1 B1 C1 D1 E1 F1 9ED1 9EE1 33 43 53 63 73 9E63 3E 65 75 9EF3 5 4 4 5 5 6 1 dd ff ff ii dd hh ll ee ff ff ee ff ff dd ff ff hh ll jj kk dd ff 5 1 1 1 5 4 6 2 3 4 4 3 3 5 4 5 1 1 5 4 6 6 3 5 6 MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 119 Chapter 7 Central Processor Unit (S08CPUV2) V H I N Z C CPX CPX CPX CPX CPX CPX CPX CPX #opr8i opr8a opr16a oprx16,X oprx8,X ,X oprx16,SP oprx8,SP DAA DBNZ opr8a,rel DBNZA rel DBNZX rel DBNZ oprx8,X,rel DBNZ ,X,rel DBNZ oprx8,SP,rel DEC opr8a DECA DECX DEC oprx8,X DEC ,X DEC oprx8,SP DIV EOR #opr8i EOR opr8a EOR opr16a EOR oprx16,X EOR oprx8,X EOR ,X EOR oprx16,SP EOR oprx8,SP INC opr8a INCA INCX INC oprx8,X INC ,X INC oprx8,SP JMP opr8a JMP opr16a JMP oprx16,X JMP oprx8,X JMP ,X JSR opr8a JSR opr16a JSR oprx16,X JSR oprx8,X JSR ,X LDA #opr8i LDA opr8a LDA opr16a LDA oprx16,X LDA oprx8,X LDA ,X LDA oprx16,SP LDA oprx8,SP LDHX #opr16i LDHX opr8a LDHX opr16a LDHX ,X LDHX oprx16,X LDHX oprx8,X LDHX oprx8,SP – – Compare X (Index Register Low) with Memory IMM DIR EXT IX2 IX1 IX SP2 SP1 A3 B3 C3 D3 E3 F3 9ED3 9EE3 INH 72 – – – – – – DIR 3B 4B 5B 6B 7B 9E6B (X) – (M) (CCR Updated But Operands Not Changed) Decimal Adjust Accumulator After ADD or ADC of BCD Values (A)10 Decrement and Branch if Not Zero Decrement A, X, or M Branch if (result) ≠ 0 DBNZX Affects X Not H U – – INH INH IX1 IX SP1 – – Decrement M ← (M) – 0x01 A ← (A) – 0x01 X ← (X) – 0x01 M ← (M) – 0x01 M ← (M) – 0x01 M ← (M) – 0x01 Divide A ← (H:A)÷(X) H ← Remainder – – – – 0 – – Exclusive OR Memory with Accumulator Increment DIR INH – INH IX1 IX SP1 – – Jump to Subroutine Load Accumulator from Memory 6 – IMM A8 B8 C8 D8 E8 F8 9ED8 9EE8 3C 4C 5C 6C 7C 9E6C BC CC DC EC FC BD CD DD ED FD A6 B6 C6 D6 E6 F6 9ED6 9EE6 45 55 32 9EAE 9EBE 9ECE 9EFE – Load Index Register (H:X) from Memory – A ← (M) 0 – – H:X ← (M:M + 0x0001) 7 4 4 7 6 8 52 – – – – – – 0 – – dd rr rr rr ff rr rr ff rr INH PC ← Jump Address PC ← (PC) + n (n = 1, 2, or 3) Push (PCL); SP ← (SP) – 0x0001 Push (PCH); SP ← (SP) – 0x0001 PC ← Unconditional Address 1 5 1 1 5 4 6 – – – – – – Jump ee ff ff 2 3 4 4 3 3 5 4 3A dd 4A 5A 6A ff 7A 9E6A ff A ← (A ⊕ M) M ← (M) + 0x01 A ← (A) + 0x01 X ← (X) + 0x01 M ← (M) + 0x01 M ← (M) + 0x01 M ← (M) + 0x01 ii dd hh ll ee ff ff Bus Cycles1 Description Operand Operation Opcode Effect on CCR Source Form Address Mode Table 7-2. HCS08 Instruction Set Summary (Sheet 4 of 7) – DIR EXT IX2 IX1 IX SP2 SP1 DIR INH INH IX1 IX SP1 DIR EXT IX2 IX1 IX DIR EXT IX2 IX1 IX IMM DIR EXT IX2 IX1 IX SP2 SP1 IMM DIR EXT IX IX2 IX1 SP1 ii dd hh ll ee ff ff ee ff ff dd ff ff dd hh ll ee ff ff dd hh ll ee ff ff ii dd hh ll ee ff ff ee ff ff jj kk dd hh ll ee ff ff ff 2 3 4 4 3 3 5 4 5 1 1 5 4 6 3 4 4 3 3 5 6 6 5 5 2 3 4 4 3 3 5 4 3 4 5 5 6 5 5 MC9S08AW60 Data Sheet, Rev.1.0 120 Freescale Semiconductor Chapter 7 Central Processor Unit (S08CPUV2) Operand DIR EXT IX2 IX1 IX SP2 SP1 DIR INH INH IX1 IX SP1 AE BE CE DE EE FE 9EDE 9EEE 38 48 58 68 78 9E68 ii dd hh ll ee ff ff DIR INH INH IX1 IX SP1 34 dd 44 54 64 ff 74 9E64 ff 5 1 1 5 4 6 – DIR/DIR 4E 5E 6E 7E 5 5 4 5 Description V H I N Z C LDX #opr8i LDX opr8a LDX opr16a LDX oprx16,X LDX oprx8,X LDX ,X LDX oprx16,SP LDX oprx8,SP LSL opr8a LSLA LSLX LSL oprx8,X LSL ,X LSL oprx8,SP LSR opr8a LSRA LSRX LSR oprx8,X LSR ,X LSR oprx8,SP 0 – – Load X (Index Register Low) from Memory X ← (M) – – Logical Shift Left (Same as ASL) C 0 b7 b0 – – 0 Logical Shift Right 0 C b7 b0 (M)destination ← (M)source MOV opr8a,opr8a MOV opr8a,X+ MOV #opr8i,opr8a MOV ,X+,opr8a Move MUL Unsigned multiply H:X ← (H:X) + 0x0001 in IX+/DIR and DIR/IX+ Modes X:A ← (X) × (A) M ← – (M) = 0x00 – (M) A ← – (A) = 0x00 – (A) X ← – (X) = 0x00 – (X) M ← – (M) = 0x00 – (M) M ← – (M) = 0x00 – (M) M ← – (M) = 0x00 – (M) NEG opr8a NEGA NEGX NEG oprx8,X NEG ,X NEG oprx8,SP Negate (Two’s Complement) NOP No Operation Uses 1 Bus Cycle NSA Nibble Swap Accumulator A ← (A[3:0]:A[7:4]) ORA ORA ORA ORA ORA ORA ORA ORA #opr8i opr8a opr16a oprx16,X oprx8,X ,X oprx16,SP oprx8,SP PSHA PSHH PSHX PULA PULH PULX ROL opr8a ROLA ROLX ROL oprx8,X ROL ,X ROL oprx8,SP 0 – – DIR/IX+ IMM/DIR IX+/DIR INH INH IX1 IX SP1 – – – – – – INH – – – – – – INH – IMM ee ff ff dd ff ff dd dd dd ii dd dd 2 3 4 4 3 3 5 4 5 1 1 5 4 6 42 5 30 dd 40 50 60 ff 70 9E60 ff 5 1 1 5 4 6 9D 1 62 1 DIR EXT IX2 IX1 IX SP2 SP1 AA BA CA DA EA FA 9EDA 9EEA Push (A); SP ← (SP) – 0x0001 – – – – – – INH 87 2 Push (H); SP ← (SP) – 0x0001 – – – – – – INH 8B 2 Push (X); SP ← (SP) – 0x0001 – – – – – – INH 89 2 SP ← (SP + 0x0001); Pull (A) – – – – – – INH 86 3 SP ← (SP + 0x0001); Pull (H) – – – – – – INH 8A 3 SP ← (SP + 0x0001); Pull (X) – – – – – – INH 88 3 39 dd 49 59 69 ff 79 9E69 ff 5 1 1 5 4 6 Inclusive OR Accumulator and Memory A ← (A) | (M) – – Rotate Left through Carry – IMM – 0 – – – 0 INH DIR – – 0 – – Push Accumulator onto Stack Push H (Index Register High) onto Stack Push X (Index Register Low) onto Stack Pull Accumulator from Stack Pull H (Index Register High) from Stack Pull X (Index Register Low) from Stack Address Mode Operation Opcode Effect on CCR Source Form Bus Cycles1 Table 7-2. HCS08 Instruction Set Summary (Sheet 5 of 7) C b7 b0 DIR INH INH IX1 IX SP1 ii dd hh ll ee ff ff ee ff ff 2 3 4 4 3 3 5 4 MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 121 Chapter 7 Central Processor Unit (S08CPUV2) Description V H I N Z C – – ROR opr8a RORA RORX ROR oprx8,X ROR ,X ROR oprx8,SP Rotate Right through Carry RSP Reset Stack Pointer RTI Return from Interrupt RTS Return from Subroutine SBC SBC SBC SBC SBC SBC SBC SBC #opr8i opr8a opr16a oprx16,X oprx8,X ,X oprx16,SP oprx8,SP SP ← 0xFF (High Byte Not Affected) SP ← (SP) + 0x0001; Pull (CCR) SP ← (SP) + 0x0001; Pull (A) SP ← (SP) + 0x0001; Pull (X) SP ← (SP) + 0x0001; Pull (PCH) SP ← (SP) + 0x0001; Pull (PCL) SP ← SP + 0x0001; Pull (PCH) SP ← SP + 0x0001; Pull (PCL) Subtract with Carry Set Interrupt Mask Bit I←1 SWI 9C 1 INH 80 9 – – – – – – INH 81 6 Store Accumulator in Memory Store H:X (Index Reg.) Enable Interrupts: Stop Processing Refer to MCU Documentation IMM DIR EXT IX2 IX1 IX SP2 SP1 A2 B2 C2 D2 E2 F2 9ED2 9EE2 – – – – – 1 INH – – 1 – – – INH 0 – – – DIR 99 A ← (A) – (M) – (C) SEI opr8a opr16a oprx16,X oprx8,X ,X oprx16,SP oprx8,SP #opr8i opr8a opr16a oprx16,X oprx8,X ,X oprx16,SP oprx8,SP – – – – – – INH – – C←1 STX STX STX STX STX STX STX SUB SUB SUB SUB SUB SUB SUB SUB 5 1 1 5 4 6 b0 Set Carry Bit STOP 36 dd 46 56 66 ff 76 9E66 ff C b7 SEC STA opr8a STA opr16a STA oprx16,X STA oprx8,X STA ,X STA oprx16,SP STA oprx8,SP STHX opr8a STHX opr16a STHX oprx8,SP DIR INH INH IX1 IX SP1 M ← (A) (M:M + 0x0001) ← (H:X) 0 – – EXT IX2 IX1 IX SP2 SP1 – DIR EXT SP1 Software Interrupt ee ff ff B7 C7 D7 E7 F7 9ED7 9EE7 35 96 9EFF 2 3 4 4 3 3 5 4 1 9B INH 8E – DIR EXT IX2 IX1 IX SP2 SP1 IMM DIR EXT IX2 IX1 IX SP2 SP1 BF CF DF EF FF 9EDF 9EEF A0 B0 C0 D0 E0 F0 9ED0 9EE0 INH 83 M ← (X) – – Subtract ii dd hh ll ee ff ff 1 dd hh ll ee ff ff ee ff ff dd hh ll ff 3 4 4 3 2 5 4 4 5 5 – – 0 – – – I bit ← 0; Stop Processing 0 – – Store X (Low 8 Bits of Index Register) in Memory Bus Cycles1 Operation Operand Effect on CCR Opcode Source Form Address Mode Table 7-2. HCS08 Instruction Set Summary (Sheet 6 of 7) A ← (A) – (M) PC ← (PC) + 0x0001 Push (PCL); SP ← (SP) – 0x0001 Push (PCH); SP ← (SP) – 0x0001 Push (X); SP ← (SP) – 0x0001 Push (A); SP ← (SP) – 0x0001 Push (CCR); SP ← (SP) – 0x0001 I ← 1; PCH ← Interrupt Vector High Byte PCL ← Interrupt Vector Low Byte 2+ dd hh ll ee ff ff ee ff ff ii dd hh ll ee ff ff ee ff ff 3 4 4 3 2 5 4 2 3 4 4 3 3 5 4 – – 1 – – – 11 MC9S08AW60 Data Sheet, Rev.1.0 122 Freescale Semiconductor Chapter 7 Central Processor Unit (S08CPUV2) V H I N Z C TAP TAX TPA Transfer Accumulator to CCR Transfer Accumulator to X (Index Register Low) Transfer CCR to Accumulator CCR ← (A) INH 84 1 X ← (A) – – – – – – INH 97 1 A ← (CCR) – – – – – – INH 85 1 0 – – 3D dd 4D 5D 6D ff 7D 9E6D ff 4 1 1 4 3 5 95 2 9F 1 94 2 8F 2+ TST opr8a TSTA TSTX TST oprx8,X TST ,X TST oprx8,SP Test for Negative or Zero (M) – 0x00 (A) – 0x00 (X) – 0x00 (M) – 0x00 (M) – 0x00 (M) – 0x00 TSX Transfer SP to Index Reg. H:X ← (SP) + 0x0001 TXA Transfer X (Index Reg. Low) to Accumulator TXS Transfer Index Reg. to SP WAIT Enable Interrupts; Wait for Interrupt 1 Bus Cycles1 Description Operand Operation Opcode Effect on CCR Source Form Address Mode Table 7-2. HCS08 Instruction Set Summary (Sheet 7 of 7) A ← (X) SP ← (H:X) – 0x0001 I bit ← 0; Halt CPU – DIR INH INH IX1 IX SP1 – – – – – – INH – – – – – – INH – – – – – – INH – – 0 – – – INH Bus clock frequency is one-half of the CPU clock frequency. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 123 Chapter 7 Central Processor Unit (S08CPUV2) Table 7-3. Opcode Map (Sheet 1 of 2) Bit-Manipulation 00 5 10 5 BRSET0 3 01 BRCLR1 3 04 BRSET2 3 05 3 07 BRSET4 3 09 BRSET5 3 0B BRSET6 3 0D BRCLR6 3 0E BRSET7 3 0F BRCLR7 3 INH IMM DIR EXT DD IX+D DIR 2 5 2F TST REL 2 3 3E CPHX REL 3 3 3F BIH REL 2 REL IX IX1 IX2 IMD DIX+ TSTA DIR 1 6 4E CLR DIR 1 ASR INH 2 1 68 INH 1 Relative Indexed, No Offset Indexed, 8-Bit Offset Indexed, 16-Bit Offset IMM to DIR DIR to IX+ ASR LSL IX1 1 5 79 ROL INH 2 1 6A DEC INH 2 4 6B ROL DEC DBNZ INH 3 1 6C DBNZ INC INH 2 1 6D TST INH 2 5 6E MOV CLRX IX1+ IX1 1 CLR ADD INH 2 1 INH 1 2 BD BSR Page 2 WAIT 5 1 JSR REL 2 2 BE LDX 2 AF TXA INH 2 Stack Pointer, 8-Bit Offset Stack Pointer, 16-Bit Offset Indexed, No Offset with Post Increment Indexed, 1-Byte Offset with Post Increment JMP DIR 3 5 CD JSR DIR 3 3 CE LDX IMM 2 2 BF AIX LDX DIR 3 3 CF STX IMM 2 EXT 3 4 DF STX DIR 3 EXT 3 Opcode in Hexadecimal F0 EOR ADC IX2 2 IX 2 STA IX 3 EOR IX 3 ADC IX1 1 3 FA ORA IX 3 ORA IX1 1 3 FB ADD JSR LDX IX1 1 3 FF IX 5 JSR IX1 1 3 FE IX1 1 IX 3 JMP IX1 1 5 FD STX IX 3 ADD IX1 1 3 FC JMP IX2 2 4 EF STX IX 3 LDA IX1 1 3 F9 IX2 2 4 EE LDX BIT IX1 1 3 F8 IX2 2 6 ED JSR EXT 3 4 DE IX 3 STA IX2 2 4 EC JMP EXT 3 6 DD AND IX1 1 3 F7 IX2 2 4 EB ADD EXT 3 4 DC IX 3 LDA IX2 2 4 EA ORA EXT 3 4 DB ADD JMP INH 2 AE INH 2+ 9F ORA CPX IX1 1 3 F6 IX2 2 4 E9 ADC EXT 3 4 DA IX 3 BIT IX2 2 4 E8 EOR IX 3 SBC IX1 1 3 F5 STA ADC DIR 3 3 CC AND IX2 2 4 E7 EXT 3 4 D9 CMP IX1 1 3 F4 IX2 2 4 E6 EXT 3 4 D8 EOR DIR 3 3 CB ADD IMM 2 BC INH 1 AD NOP IX 1 IMM 2 2 BB CPX LDA STA IX 3 IX1 1 3 F3 IX2 2 4 E5 EXT 3 4 D7 DIR 3 3 CA ORA RSP 1 2+ 9E STOP ADC SBC BIT LDA DIR 3 3 C9 IMM 2 2 BA ORA SEI INH 1 9D IX 5 8E MOV ADC INH 2 1 AB INH 1 1 9C CLRH IX 1 3 IMD 2 IX+D 1 5 7F 4 8F CLR INH 2 INH 1 2 9B EOR AND 3 SUB IX1 1 3 F2 IX2 2 4 E4 EXT 3 4 D6 DIR 3 3 C8 IMM 2 2 B9 INH 2 1 AA CLI TST IX1 1 4 7E MOV SP1 SP2 IX+ INC IX1 1 4 7D SEC INH 1 3 9A PSHH IX 1 4 8C EOR CPX BIT STA CMP IX2 2 4 E3 EXT 3 4 D5 DIR 3 3 C7 IMM 2 2 B8 INH 2 1 A9 PULH IX 1 6 8B IX1 2 5 7C CLC INH 1 2 99 AND LDA AIS INH 2 1 A8 SBC F0 IX1 1 3 F1 IX2 2 4 E2 EXT 3 4 D4 DIR 3 3 C6 IMM 2 2 B7 TAX CPX BIT LDA CMP EXT 3 4 D3 DIR 3 3 C5 IMM 2 2 B6 EXT 2 1 A7 INH 1 3 98 PSHX IX 1 4 8A IX1 1 7 7B INH 3 2 97 PULX IX 1 4 89 IX1 1 5 7A STHX PSHA IX 1 4 88 LSL INH 2 1 69 PULA IX 1 4 87 IX1 1 5 78 DD 2 DIX+ 3 1 5F 1 6F CLRA ROR AND BIT INH 2 5 A6 SBC 3 SUB IX2 2 4 E1 EXT 3 4 D2 DIR 3 3 C4 IMM 2 2 B5 TSX INH 1 3 96 CPX AND CMP E0 SUB EXT 3 4 D1 DIR 3 3 C3 IMM 2 2 B4 INH 2 2 A5 TPA DIR 1 4 86 IX1 1 5 77 TSTX INH 1 5 5E MOV EXT 3 5 4F INH 2 1 67 INCX INH 1 1 5D CPHX TXS INH 1 1 95 SBC CPX SUB DIR 3 3 C2 IMM 2 2 B3 REL 2 2 A4 TAP IX 1 5 85 IMM 2 5 76 ROR DBNZX INH 2 1 5C INCA DIR 1 4 4D CPHX DIR 3 1 66 DECX INH 1 4 5B DBNZA DIR 2 5 4C INC REL 2 3 3D BIL DECA DIR 1 7 4B DBNZ BMS DIR 2 5 2E Inherent Immediate Direct Extended DIR to DIR IX+ to DIR DEC LSR CMP SBC BLE Register/Memory C0 4 D0 4 DIR 3 3 C1 IMM 2 2 B2 REL 2 3 A3 INH 2 1 94 3 SUB CMP BGT SWI B0 IMM 2 2 B1 REL 2 3 A2 INH 2 11 93 IX 1 4 84 2 SUB BLT INH 2 5+ 92 BGND COM A0 REL 2 3 A1 RTS INH 1 4 83 IX1 1 3 75 ROLX INH 1 1 5A DAA 3 BGE INH 2 6 91 IX+ 1 1 82 LSR LSLX INH 1 1 59 CBEQ IX1 1 5 74 INH 2 4 65 ASRX INH 1 1 58 ROLA DIR 1 5 4A BMC DIR 2 5 2D DIR 2 ROL REL 3 3 3C INH 1 1 57 LSLA DIR 1 5 49 REL 2 3 3B BMI DIR 2 5 2C BCLR7 DIR 2 LSL COM RTI IX 1 5 81 INH 1 5 73 INH 2 1 64 RORX ASRA DIR 1 5 48 REL 2 3 3A DIR 2 5 2B BSET7 DIR 2 5 1F ASR BHCS BPL RORA DIR 1 5 47 REL 2 3 39 DIR 2 5 2A BCLR6 DIR 2 5 1E ROR INH 1 1 63 Control 9 90 80 NEG NSA LDHX IMM 2 1 56 4 IX1+ 2 1 72 LSRX INH 1 3 55 LDHX DIR 3 5 46 BHCC DIR 2 5 29 BSET6 DIR 2 5 1D STHX CBEQ COMX INH 1 1 54 LSRA DIR 1 4 45 REL 2 3 38 BCLR5 DIR 2 5 1C LSR BEQ INH 1 1 53 70 IX1 1 5 71 IMM 3 6 62 DIV COMA DIR 1 5 44 REL 2 3 37 BSET5 DIR 2 5 1B BRCLR5 3 0C BNE DIR 2 5 28 BCLR4 DIR 2 5 1A COM REL 2 3 36 DIR 2 5 27 BSET4 DIR 2 5 19 BRCLR4 3 0A BCS MUL 5 NEG INH 2 4 61 CBEQX IMM 3 5 52 EXT 1 5 43 REL 2 3 35 DIR 2 5 26 CBEQA LDHX NEGX INH 1 4 51 DIR 3 5 42 BCC BCLR3 DIR 2 5 18 CBEQ REL 2 3 34 DIR 2 5 25 BSET3 DIR 2 5 17 BRCLR3 3 08 BLS NEGA DIR 1 5 41 REL 3 3 33 DIR 2 5 24 BCLR2 DIR 2 5 16 BRSET3 DIR 2 5 23 Read-Modify-Write 1 50 1 60 40 NEG REL 3 3 32 BHI BSET2 DIR 2 5 15 BRCLR2 3 06 BRN DIR 2 5 22 BCLR1 DIR 2 5 14 5 REL 2 3 31 BSET1 DIR 2 5 13 30 BRA DIR 2 5 21 BCLR0 DIR 2 5 12 BRSET1 3 03 BSET0 DIR 2 5 11 BRCLR0 3 02 Branch 20 3 IX 3 LDX IX 2 STX IX 3 HCS08 Cycles Instruction Mnemonic IX Addressing Mode SUB Number of Bytes 1 MC9S08AW60 Data Sheet, Rev.1.0 124 Freescale Semiconductor Chapter 7 Central Processor Unit (S08CPUV2) Table 7-3. Opcode Map (Sheet 2 of 2) Bit-Manipulation Branch Read-Modify-Write 9E60 Control Register/Memory 9ED0 5 6 NEG CMP SP1 CMP 4 SP2 3 SP1 9ED2 5 9EE2 4 SBC 9E63 SBC 4 SP2 3 SP1 9ED3 5 9EE3 4 9EF3 6 COM CPX 3 SP1 9E64 6 CPX AND SP1 SP1 AND 4 SP2 3 SP1 9ED5 5 9EE5 4 BIT BIT 6 4 SP2 3 SP1 9ED6 5 9EE6 4 3 SP1 9E67 6 4 SP2 3 SP1 9ED7 5 9EE7 4 9E66 6 CPHX 4 SP2 3 SP1 3 9ED4 5 9EE4 4 LSR 3 4 SUB 4 SP2 3 SP1 9ED1 5 9EE1 4 CBEQ 4 9EE0 SUB 3 SP1 9E61 6 ROR LDA ASR LDA STA 3 SP1 9E68 6 STA 4 SP2 3 SP1 9ED8 5 9EE8 4 LSL EOR 3 SP1 9E69 6 EOR 4 SP2 3 SP1 9ED9 5 9EE9 4 ROL ADC 3 SP1 9E6A 6 ADC 4 SP2 3 SP1 9EDA 5 9EEA 4 DEC ORA 3 SP1 9E6B 8 ORA 4 SP2 3 SP1 9EDB 5 9EEB 4 DBNZ ADD 4 SP1 9E6C 6 4 ADD SP2 3 SP1 INC 3 SP1 9E6D 5 TST 3 SP1 9EAE 5 9EBE LDHX 2 9E6F IX 4 6 9ECE LDHX 5 9EDE LDHX IX2 3 6 CLR 3 INH IMM DIR EXT DD IX+D Inherent Immediate Direct Extended DIR to DIR IX+ to DIR REL IX IX1 IX2 IMD DIX+ Relative Indexed, No Offset Indexed, 8-Bit Offset Indexed, 16-Bit Offset IMM to DIR DIR to IX+ SP1 SP2 IX+ IX1+ Note: All Sheet 2 Opcodes are Preceded by the Page 2 Prebyte (9E) 5 9EEE LDX 4 9EFE LDX 5 LDHX IX1 4 SP2 3 SP1 3 SP1 9EDF 5 9EEF 4 9EFF 5 STX SP1 4 SP2 3 STX SP1 3 STHX SP1 Stack Pointer, 8-Bit Offset Stack Pointer, 16-Bit Offset Indexed, No Offset with Post Increment Indexed, 1-Byte Offset with Post Increment Prebyte (9E) and Opcode in Hexadecimal 9E60 6 HCS08 Cycles Instruction Mnemonic SP1 Addressing Mode NEG Number of Bytes 3 MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 125 Chapter 7 Central Processor Unit (S08CPUV2) MC9S08AW60 Data Sheet, Rev.1.0 126 Freescale Semiconductor Chapter 8 Internal Clock Generator (S08ICGV4) The internal clock generation (ICG) module is used to generate the system clocks for the MC9S08AW60/48/32/16 MCU. The analog supply lines VDDA and VSSA are internally derived from the MCU’s VDD and VSS pins. Electrical parametric data for the ICG may be found in Appendix A, “Electrical Characteristics and Timing Specifications.” ICGERCLK SYSTEM CONTROL LOGIC TPM1 TPM2 IIC1 SCI1 SCI2 SPI1 RTI FFE ÷2 ICG FIXED FREQ CLOCK (XCLK) ICGOUT ÷2 BUSCLK ICGLCLK* CPU BDC * ICGLCLK is the alternate BDC clock source for the MC9S08AW60/48/32/16. ADC RAM ADC has min and max frequency requirements. See Chapter 14, “Analog-to-Digital Converter (S08ADC10V1) and Appendix A, “Electrical Characteristics and Timing Specifications FLASH FLASH has frequency requirements for program and erase operation. See Appendix A, “Electrical Characteristics and Timing Specifications. Figure 8-1. System Clock Distribution Diagram NOTE Freescale Semiconductor recommends that FLASH location $FFBE be reserved to store a nonvolatile version of ICGTRM. This will allow debugger and programmer vendors to perform a manual trim operation and store the resultant ICGTRM value for users to access at a later time. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 127 HCS08 CORE BDC DEBUG MODULE (DBG) RTI COP IRQ LVD SERIAL COMMUNICATIONS INTERFACE MODULE (SCI2) IIC MODULE (IIC1) 10-BIT ANALOG-TO-DIGITAL CONVERTER (ADC1) TxD2 SDA1 SCL1 6-CHANNEL TIMER/PWM MODULE (TPM1) INTERNAL CLOCK GENERATOR (ICG) LOW-POWER OSCILLATOR SERIAL COMMUNICATIONS INTERFACE MODULE (SCI1) VOLTAGE REGULATOR 2-CHANNEL TIMER/PWM MODULE (TPM2) SPSCK1 MOSI1 PTE7/SPSCK1 MISO1 SS1 TPM1CLK TPM1CH5– TPM1CH0 RxD1 TxD1 PORT E USER RAM AW60/48/32 = 2048 BYTES AW16 = 1024 BYTES PTD7/AD1P15/KBI1P7 PTD6/AD1P14/TPM1CLK PTD5/AD1P13 PTD4/AD1P12/TPM2CLK PTD3/AD1P11/KBI1P6 PTD2/AD1P10/KBI1P5 PTD1/AD1P9 PTD0/AD1P8 8 8 AD1P15–AD1P8 USER FLASH (AW60 = 63,280 BYTES) (AW48 = 49,152 BYTES) (AW32 = 32,768 BYTES) (AW16 = 16,384 BYTES) SERIAL PERIPHERAL INTERFACE MODULE (SPI1) PTC6 PTC5/RxD2 PTC4 PTC3/TxD2 PTC2/MCLK PTC1/SDA1 PTC0/SCL1 RxD2 AD1P7–AD1P0 VSSAD VREFL VREFH 6 TPM2CLK PORT F VSS PTB7/AD1P7– PTB0/AD1P0 PORT C RESETS AND INTERRUPTS MODES OF OPERATION POWER MANAGEMENT VDDAD VDD 8 PORT D IRQ PTA7– PTA0 HCS08 SYSTEM CONTROL TPM2CH1–TPM2CH0 2 KBI1P7–KBI1P5 3 8-BIT KEYBOARD INTERRUPT MODULE (KBI1) KBI1P4–KBI1P0 EXTAL XTAL 5 NOTES: 1. Port pins are software configurable with pullup device if input port. 2. Pin contains software configurable pullup/pulldown device if IRQ is enabled (IRQPE = 1). Pulldown is enabled if rising edge detect is selected (IRQEDG = 1) 3. IRQ does not have a clamp diode to VDD. IRQ should not be driven above VDD. 4. Pin contains integrated pullup device. 5. Pins PTD7, PTD3, PTD2, and PTG4 contain both pullup and pulldown devices. Pulldown enabled when KBI is enabled (KBIPEn = 1) and rising edge is selected (KBEDGn = 1). PORT G RESET 8 CPU PORT B BKGD/MS PORT A Chapter 8 Internal Clock Generator (S08ICGV4) PTE6/MOSI1 PTE5/MISO1 PTE4/SS1 PTE3/TPM1CH1 PTE2/TPM1CH0 PTE1/RxD1 PTE0/TxD1 PTF7 PTF6 PTF5/TPM2CH1 PTF4/TPM2CH0 PTF3/TPM1CH5 PTF2/TPM1CH4 PTF1/TPM1CH3 PTF0/TPM1CH2 PTG6/EXTAL PTG5/XTAL PTG4/KBI1P4 PTG3/KBI1P3 PTG2/KBI1P2 PTG1/KBI1P1 PTG0/KBI1P0 Figure 8-2. Block Diagram Highlighting ICG Module MC9S08AW60 Data Sheet, Rev.1.0 128 Freescale Semiconductor Internal Clock Generator (S08ICGV4) 8.1 Introduction Figure 8-3 is a top-level diagram that shows the functional organization of the internal clock generation (ICG) module. This section includes a general description and a feature list. EXTAL OSCILLATOR (OSC) WITH EXTERNAL REF SELECT ICG CLOCK SELECT ICGERCLK XTAL ICGDCLK REF SELECT VDDA (SEE NOTE 2) FREQUENCY LOCKED LOOP (FLL) DCO OUTPUT CLOCK SELECT /R ICGOUT LOSS OF LOCK AND CLOCK DETECTOR V SSA (SEE NOTE 2) FIXED CLOCK SELECT IRG INTERNAL TYP 243 kHz REFERENCE 8 MHz GENERATORS RG FFE ICGIRCLK LOCAL CLOCK FOR OPTIONAL USE WITH BDC ICGLCLK NOTES: 1. See Table 8-1 for specific use of ICGOUT, FFE, ICGLCLK, ICGERCLK 2. Not all HCS08 microcontrollers have unique supply pins for the ICG. See the device pin assignments. Figure 8-3. ICG Block Diagram The ICG provides multiple options for clock sources. This offers a user great flexibility when making choices between cost, precision, current draw, and performance. As seen in Figure 8-3, the ICG consists of four functional blocks. Each of these is briefly described here and then in more detail in a later section. • Oscillator block — The oscillator block provides means for connecting an external crystal or resonator. Two frequency ranges are software selectable to allow optimal startup and stability. Alternatively, the oscillator block can be used to route an external square wave to the system clock. External sources can provide a very precise clock source. The oscillator is capable of being configured for low power mode or high amplitude mode as selected by HGO. • Internal reference generator — The internal reference generator consists of two controlled clock sources. One is designed to be approximately 8 MHz and can be selected as a local clock for the background debug controller. The other internal reference clock source is typically 243 kHz and can be trimmed for finer accuracy via software when a precise timed event is input to the MCU. This provides a highly reliable, low-cost clock source. • Frequency-locked loop — A frequency-locked loop (FLL) stage takes either the internal or external clock source and multiplies it to a higher frequency. Status bits provide information when the circuit has achieved lock and when it falls out of lock. Additionally, this block can monitor the external reference clock and signals whether the clock is valid or not. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 129 Internal Clock Generator (S08ICGV4) • 8.1.1 Clock select block — The clock select block provides several switch options for connecting different clock sources to the system clock tree. ICGDCLK is the multiplied clock frequency out of the FLL, ICGERCLK is the reference clock frequency from the crystal or external clock source, and FFE (fixed frequency enable) is a control signal used to control the system fixed frequency clock (XCLK). ICGLCLK is the clock source for the background debug controller (BDC). Features The module is intended to be very user friendly with many of the features occurring automatically without user intervention. To quickly configure the module, go to Section 8.5, “Initialization/Application Information” and pick an example that best suits the application needs. Features of the ICG and clock distribution system: • Several options for the primary clock source allow a wide range of cost, frequency, and precision choices: — 32 kHz–100 kHz crystal or resonator — 1 MHz–16 MHz crystal or resonator — External clock — Internal reference generator • Defaults to self-clocked mode to minimize startup delays • Frequency-locked loop (FLL) generates 8 MHz to 40 MHz (for bus rates up to 20 MHz) — Uses external or internal clock as reference frequency • Automatic lockout of non-running clock sources • Reset or interrupt on loss of clock or loss of FLL lock • Digitally-controlled oscillator (DCO) preserves previous frequency settings, allowing fast frequency lock when recovering from stop3 mode • DCO will maintain operating frequency during a loss or removal of reference clock • Post-FLL divider selects 1 of 8 bus rate divisors (/1 through /128) • Separate self-clocked source for real-time interrupt • Trimmable internal clock source supports SCI communications without additional external components • Automatic FLL engagement after lock is acquired • External oscillator selectable for low power or high gain 8.1.2 Modes of Operation This is a high-level description only. Detailed descriptions of operating modes are contained in Section 8.4, “Functional Description.” • Mode 1 — Off The output clock, ICGOUT, is static. This mode may be entered when the STOP instruction is executed. MC9S08AW60 Data Sheet, Rev.1.0 130 Freescale Semiconductor Internal Clock Generator (S08ICGV4) • • • • 8.2 Mode 2 — Self-clocked (SCM) Default mode of operation that is entered immediately after reset. The ICG’s FLL is open loop and the digitally controlled oscillator (DCO) is free running at a frequency set by the filter bits. Mode 3 — FLL engaged internal (FEI) In this mode, the ICG’s FLL is used to create frequencies that are programmable multiples of the internal reference clock. — FLL engaged internal unlocked is a transition state that occurs while the FLL is attempting to lock. The FLL DCO frequency is off target and the FLL is adjusting the DCO to match the target frequency. — FLL engaged internal locked is a state that occurs when the FLL detects that the DCO is locked to a multiple of the internal reference. Mode 4 — FLL bypassed external (FBE) In this mode, the ICG is configured to bypass the FLL and use an external clock as the clock source. Mode 5 — FLL engaged external (FEE) The ICG’s FLL is used to generate frequencies that are programmable multiples of the external clock reference. — FLL engaged external unlocked is a transition state that occurs while the FLL is attempting to lock. The FLL DCO frequency is off target and the FLL is adjusting the DCO to match the target frequency. — FLL engaged external locked is a state which occurs when the FLL detects that the DCO is locked to a multiple of the internal reference. External Signal Description The oscillator pins are used to provide an external clock source for the MCU. 8.2.1 EXTAL — External Reference Clock / Oscillator Input If upon the first write to ICGC1, either the FEE mode or FBE mode is selected, this pin functions as either the external clock input or the input of the oscillator circuit as determined by REFS. If upon the first write to ICGC1, either the FEI mode or SCM mode is selected, this pin is not used by the ICG. 8.2.2 XTAL — Oscillator Output If upon the first write to ICGC1, either the FEE mode or FBE mode is selected, this pin functions as the output of the oscillator circuit. If upon the first write to ICGC1, either the FEI mode or SCM mode is selected, this pin is not used by the ICG. The oscillator is capable of being configured to provide a higher amplitude output for improved noise immunity. This mode of operation is selected by HGO = 1. 8.2.3 External Clock Connections If an external clock is used, then the pins are connected as shown Figure 8-4. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 131 Internal Clock Generator (S08ICGV4) ICG EXTAL XTAL VSS NOT CONNECTED CLOCK INPUT Figure 8-4. External Clock Connections 8.2.4 External Crystal/Resonator Connections If an external crystal/resonator frequency reference is used, then the pins are connected as shown below. Recommended component values are listed in the Electrical Characteristics chapter. ICG EXTAL VSS XTAL RS C1 C2 RF CRYSTAL OR RESONATOR Figure 8-5. External Frequency Reference Connection 8.3 Register Definition Refer to the direct-page register summary in the Memory chapter of this data sheet for the absolute address assignments for all ICG registers. This section refers to registers and control bits only by their names. A Freescale-provided equate or header file is used to translate these names into the appropriate absolute addresses. Table 8-1 is a summary of ICG registers. MC9S08AW60 Data Sheet, Rev.1.0 132 Freescale Semiconductor Internal Clock Generator (S08ICGV4) Table 8-1. ICG Register Summary Name 7 6 5 HGO RANGE REFS 4 3 2 1 OSCSTEN LOCD R ICGC1 0 0 CLKS W R ICGC2 LOLRE MFD LOCRE RFD W R CLKST REFST LOLS LOCK LOCS ERCS ICGIF ICGS1 W 1 R 0 0 0 0 0 0 0 0 0 0 0 DCOS ICGS2 W R ICGFLTU FLT W R ICGFLTL FLT W R ICGTRM TRIM W = Unimplemented or Reserved 8.3.1 R ICG Control Register 1 (ICGC1) 7 6 5 HGO1 RANGE REFS 0 1 0 4 3 2 1 OSCSTEN LOCD 1 0 0 0 CLKS W Reset 0 0 0 = Unimplemented or Reserved Figure 8-6. ICG Control Register 1 (ICGC1) 1 This bit can be written only once after reset. Additional writes are ignored. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 133 Internal Clock Generator (S08ICGV4) Table 8-2. ICGC1 Register Field Descriptions Field 7 HGO Description High Gain Oscillator Select — The HGO bit is used to select between low power operation and high gain operation for improved noise immunity. This bit is write-once after reset. 0 Oscillator configured for low power operation. 1 Oscillator configured for high gain operation. 6 RANGE Frequency Range Select — The RANGE bit controls the oscillator, reference divider, and FLL loop prescaler multiplication factor (P). It selects one of two reference frequency ranges for the ICG. The RANGE bit is write-once after a reset. The RANGE bit only has an effect in FLL engaged external and FLL bypassed external modes. 0 Oscillator configured for low frequency range. FLL loop prescale factor P is 64. 1 Oscillator configured for high frequency range. FLL loop prescale factor P is 1. 5 REFS External Reference Select — The REFS bit controls the external reference clock source for ICGERCLK. The REFS bit is write-once after a reset. 0 External clock requested. 1 Oscillator using crystal or resonator requested. 4:3 CLKS Clock Mode Select — The CLKS bits control the clock mode as described below. If FLL bypassed external is requested, it will not be selected until ERCS = 1. If the ICG enters off mode, the CLKS bits will remain unchanged. Writes to the CLKS bits will not take effect if a previous write is not complete. 00 Self-clocked 01 FLL engaged, internal reference 10 FLL bypassed, external reference 11 FLL engaged, external reference The CLKS bits are writable at any time, unless the first write after a reset was CLKS = 0X, the CLKS bits cannot be written to 1X until after the next reset (because the EXTAL pin was not reserved). 2 OSCSTEN 1 LOCD Enable Oscillator in Off Mode — The OSCSTEN bit controls whether or not the oscillator circuit remains enabled when the ICG enters off mode. This bit has no effect if HGO = 1 and RANGE = 1. 0 Oscillator disabled when ICG is in off mode unless ENABLE is high, CLKS = 10, and REFST = 1. 1 Oscillator enabled when ICG is in off mode, CLKS = 1X and REFST = 1. Loss of Clock Disable 0 Loss of clock detection enabled. 1 Loss of clock detection disabled. MC9S08AW60 Data Sheet, Rev.1.0 134 Freescale Semiconductor Internal Clock Generator (S08ICGV4) 8.3.2 ICG Control Register 2 (ICGC2) 7 6 5 4 3 2 1 0 R LOLRE MFD LOCRE RFD W Reset 0 0 0 0 0 0 0 0 Figure 8-7. ICG Control Register 2 (ICGC2) Table 8-3. ICGC2 Register Field Descriptions Field Description 7 LOLRE Loss of Lock Reset Enable — The LOLRE bit determines what type of request is made by the ICG following a loss of lock indication. The LOLRE bit only has an effect when LOLS is set. 0 Generate an interrupt request on loss of lock. 1 Generate a reset request on loss of lock. 6:4 MFD Multiplication Factor — The MFD bits control the programmable multiplication factor in the FLL loop. The value specified by the MFD bits establishes the multiplication factor (N) applied to the reference frequency. Writes to the MFD bits will not take effect if a previous write is not complete. Select a low enough value for N such that fICGDCLK does not exceed its maximum specified value. 000 Multiplication factor = 4 001 Multiplication factor = 6 010 Multiplication factor = 8 011 Multiplication factor = 10 100 Multiplication factor = 12 101 Multiplication factor = 14 110 Multiplication factor = 16 111 Multiplication factor = 18 3 LOCRE Loss of Clock Reset Enable — The LOCRE bit determines how the system manages a loss of clock condition. 0 Generate an interrupt request on loss of clock. 1 Generate a reset request on loss of clock. 2:0 RFD Reduced Frequency Divider — The RFD bits control the value of the divider following the clock select circuitry. The value specified by the RFD bits establishes the division factor (R) applied to the selected output clock source. Writes to the RFD bits will not take effect if a previous write is not complete. 000 Division factor = 1 001 Division factor = 2 010 Division factor = 4 011 Division factor = 8 100 Division factor = 16 101 Division factor = 32 110 Division factor = 64 111 Division factor = 128 MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 135 Internal Clock Generator (S08ICGV4) 8.3.3 ICG Status Register 1 (ICGS1) 7 R 6 CLKST 5 4 3 2 1 0 REFST LOLS LOCK LOCS ERCS ICGIF W Reset 1 0 0 0 0 0 0 0 0 = Unimplemented or Reserved Figure 8-8. ICG Status Register 1 (ICGS1) Table 8-4. ICGS1 Register Field Descriptions Field Description 7:6 CLKST Clock Mode Status — The CLKST bits indicate the current clock mode. The CLKST bits don’t update immediately after a write to the CLKS bits due to internal synchronization between clock domains. 00 Self-clocked 01 FLL engaged, internal reference 10 FLL bypassed, external reference 11 FLL engaged, external reference 5 REFST Reference Clock Status — The REFST bit indicates which clock reference is currently selected by the Reference Select circuit. 0 External Clock selected. 1 Crystal/Resonator selected. 4 LOLS FLL Loss of Lock Status — The LOLS bit is a sticky indication of FLL lock status. 0 FLL has not unexpectedly lost lock since LOLS was last cleared. 1 FLL has unexpectedly lost lock since LOLS was last cleared, LOLRE determines action taken.FLL has unexpectedly lost lock since LOLS was last cleared, LOLRE determines action taken. 3 LOCK FLL Lock Status — The LOCK bit indicates whether the FLL has acquired lock. The LOCK bit is cleared in off, self-clocked, and FLL bypassed modes. 0 FLL is currently unlocked. 1 FLL is currently locked. 2 LOCS Loss Of Clock Status — The LOCS bit is an indication of ICG loss of clock status. 0 ICG has not lost clock since LOCS was last cleared. 1 ICG has lost clock since LOCS was last cleared, LOCRE determines action taken. 1 ERCS External Reference Clock Status — The ERCS bit is an indication of whether or not the external reference clock (ICGERCLK) meets the minimum frequency requirement. 0 External reference clock is not stable, frequency requirement is not met. 1 External reference clock is stable, frequency requirement is met. 0 ICGIF ICG Interrupt Flag — The ICGIF read/write flag is set when an ICG interrupt request is pending. It is cleared by a reset or by reading the ICG status register when ICGIF is set and then writing a logic 1 to ICGIF. If another ICG interrupt occurs before the clearing sequence is complete, the sequence is reset so ICGIF would remain set after the clear sequence was completed for the earlier interrupt. Writing a logic 0 to ICGIF has no effect. 0 No ICG interrupt request is pending. 1 An ICG interrupt request is pending. MC9S08AW60 Data Sheet, Rev.1.0 136 Freescale Semiconductor Internal Clock Generator (S08ICGV4) 8.3.4 R ICG Status Register 2 (ICGS2) 7 6 5 4 3 2 1 0 0 0 0 0 0 0 0 DCOS 0 0 0 0 0 0 0 0 W Reset = Unimplemented or Reserved Figure 8-9. ICG Status Register 2 (ICGS2) Table 8-5. ICGS2 Register Field Descriptions Field Description 0 DCOS DCO Clock Stable — The DCOS bit is set when the DCO clock (ICG2DCLK) is stable, meaning the count error has not changed by more than nunlock for two consecutive samples and the DCO clock is not static. This bit is used when exiting off state if CLKS = X1 to determine when to switch to the requested clock mode. It is also used in self-clocked mode to determine when to start monitoring the DCO clock. This bit is cleared upon entering the off state. 0 DCO clock is unstable. 1 DCO clock is stable. 8.3.5 R ICG Filter Registers (ICGFLTU, ICGFLTL) 7 6 5 4 0 0 0 0 3 2 1 0 0 0 FLT W Reset 0 0 0 0 0 0 = Unimplemented or Reserved Figure 8-10. ICG Upper Filter Register (ICGFLTU) Table 8-6. ICGFLTU Register Field Descriptions Field Description 3:0 FLT Filter Value — The FLT bits indicate the current filter value, which controls the DCO frequency. The FLT bits are read only except when the CLKS bits are programmed to self-clocked mode (CLKS = 00). In self-clocked mode, any write to ICGFLTU updates the current 12-bit filter value. Writes to the ICGFLTU register will not affect FLT if a previous latch sequence is not complete. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 137 Internal Clock Generator (S08ICGV4) 7 6 5 4 3 2 1 0 0 0 0 0 R FLT W Reset 1 1 0 0 Figure 8-11. ICG Lower Filter Register (ICGFLTL) Table 8-7. ICGFLTL Register Field Descriptions Field Description 7:0 FLT Filter Value — The FLT bits indicate the current filter value, which controls the DCO frequency. The FLT bits are read only except when the CLKS bits are programmed to self-clocked mode (CLKS = 00). In self-clocked mode, any write to ICGFLTU updates the current 12-bit filter value. Writes to the ICGFLTU register will not affect FLT if a previous latch sequence is not complete. The filter registers show the filter value (FLT). 8.3.6 ICG Trim Register (ICGTRM) 7 6 5 4 3 2 1 0 R TRIM W POR 1 0 0 0 0 0 0 0 Reset: U U U U U U U U U = Unaffected by MCU reset Figure 8-12. ICG Trim Register (ICGTRM) Table 8-8. ICGTRM Register Field Descriptions Field Description 7 TRIM ICG Trim Setting — The TRIM bits control the internal reference generator frequency. They allow a ±25% adjustment of the nominal (POR) period. The bit’s effect on period is binary weighted (i.e., bit 1 will adjust twice as much as changing bit 0). Increasing the binary value in TRIM will increase the period and decreasing the value will decrease the period. 8.4 Functional Description This section provides a functional description of each of the five operating modes of the ICG. Also discussed are the loss of clock and loss of lock errors and requirements for entry into each mode. The ICG is very flexible, and in some configurations, it is possible to exceed certain clock specifications. When using the FLL, configure the ICG so that the frequency of ICGDCLK does not exceed its maximum value to ensure proper MCU operation. MC9S08AW60 Data Sheet, Rev.1.0 138 Freescale Semiconductor Internal Clock Generator (S08ICGV4) 8.4.1 Off Mode (Off) Normally when the CPU enters stop mode, the ICG will cease all clock activity and is in the off state. However there are two cases to consider when clock activity continues while the CPU is in stop mode, 8.4.1.1 BDM Active When the BDM is enabled, the ICG continues activity as originally programmed. This allows access to memory and control registers via the BDC controller. 8.4.1.2 OSCSTEN Bit Set When the oscillator is enabled in stop mode (OSCSTEN = 1), the individual clock generators are enabled but the clock feed to the rest of the MCU is turned off. This option is provided to avoid long oscillator startup times if necessary, or to run the RTI from the oscillator during stop3. 8.4.1.3 Stop/Off Mode Recovery Upon the CPU exiting stop mode due to an interrupt, the previously set control bits are valid and the system clock feed resumes. If FEE is selected, the ICG will source the internal reference until the external clock is stable. If FBE is selected, the ICG will wait for the external clock to stabilize before enabling ICGOUT. Upon the CPU exiting stop mode due to a reset, the previously set ICG control bits are ignored and the default reset values applied. Therefore the ICG will exit stop in SCM mode configured for an approximately 8 MHz DCO output (4 MHz bus clock) with trim value maintained. If using a crystal, 4096 clocks are detected prior to engaging ICGERCLK. This is incorporated in crystal start-up time. 8.4.2 Self-Clocked Mode (SCM) Self-clocked mode (SCM) is the default mode of operation and is entered when any of the following conditions occur: • After any reset. • Exiting from off mode when CLKS does not equal 10. If CLKS = X1, the ICG enters this state temporarily until the DCO is stable (DCOS = 1). • CLKS bits are written from X1 to 00. • CLKS = 1X and ICGERCLK is not detected (both ERCS = 0 and LOCS = 1). In this state, the FLL loop is open. The DCO is on, and the output clock signal ICGOUT frequency is given by fICGDCLK / R. The ICGDCLK frequency can be varied from 8 MHz to 40 MHz by writing a new value into the filter registers (ICGFLTH and ICGFLTL). This is the only mode in which the filter registers can be written. If this mode is entered due to a reset, fICGDCLK will default to fSelf_reset which is nominally 8 MHz. If this mode is entered from FLL engaged internal, fICGDCLK will maintain the previous frequency.If this mode is entered from FLL engaged external (either by programming CLKS or due to a loss of external reference clock), fICGDCLK will maintain the previous frequency, but ICGOUT will double if the FLL was unlocked. If this mode is entered from off mode, fICGDCLK will be equal to the frequency of ICGDCLK before MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 139 Internal Clock Generator (S08ICGV4) entering off mode. If CLKS bits are set to 01 or 11 coming out of the Off state, the ICG enters this mode until ICGDCLK is stable as determined by the DCOS bit. After ICGDCLK is considered stable, the ICG automatically closes the loop by switching to FLL engaged (internal or external) as selected by the CLKS bits. CLKST REFERENCE DIVIDER (/7) ICGIRCLK CLKS RFD CLOCK SELECT CIRCUIT REDUCED FREQUENCY DIVIDER (R) RANGE ICGOUT ICGDCLK FLT MFD 1x DIGITALLY CONTROLLED OSCILLATOR 2x DIGITAL LOOP FILTER SUBTRACTOR FLL ANALOG ICGERCLK CLKST FREQUENCYLOCKED LOOP (FLL) OVERFLOW ICG2DCLK PULSE COUNTER COUNTER ENABLE RANGE LOCK AND LOSS OF CLOCK DETECTOR DCOS LOCK LOLS LOCS ERCS RESET AND INTERRUPT CONTROL LOCD IRQ RESET ICGIF LOLRE LOCRE Figure 8-13. Detailed Frequency-Locked Loop Block Diagram 8.4.3 FLL Engaged, Internal Clock (FEI) Mode FLL engaged internal (FEI) is entered when any of the following conditions occur: • CLKS bits are written to 01 • The DCO clock stabilizes (DCOS = 1) while in SCM upon exiting the off state with CLKS = 01 In FLL engaged internal mode, the reference clock is derived from the internal reference clock ICGIRCLK, and the FLL loop will attempt to lock the ICGDCLK frequency to the desired value, as selected by the MFD bits. MC9S08AW60 Data Sheet, Rev.1.0 140 Freescale Semiconductor Internal Clock Generator (S08ICGV4) 8.4.4 FLL Engaged Internal Unlocked FEI unlocked is a temporary state that is entered when FEI is entered and the count error (∆n) output from the subtractor is greater than the maximum nunlock or less than the minimum nunlock, as required by the lock detector to detect the unlock condition. The ICG will remain in this state while the count error (∆n) is greater than the maximum nlock or less than the minimum nlock, as required by the lock detector to detect the lock condition. In this state the output clock signal ICGOUT frequency is given by fICGDCLK / R. 8.4.5 FLL Engaged Internal Locked FLL engaged internal locked is entered from FEI unlocked when the count error (∆n), which comes from the subtractor, is less than nlock (max) and greater than nlock (min) for a given number of samples, as required by the lock detector to detect the lock condition. The output clock signal ICGOUT frequency is given by fICGDCLK / R. In FEI locked, the filter value is updated only once every four comparison cycles. The update made is an average of the error measurements taken in the four previous comparisons. 8.4.6 FLL Bypassed, External Clock (FBE) Mode FLL bypassed external (FBE) is entered when any of the following conditions occur: • From SCM when CLKS = 10 and ERCS is high • When CLKS = 10, ERCS = 1 upon entering off mode, and off is then exited • From FLL engaged external mode if a loss of DCO clock occurs and the external reference remains valid (both LOCS = 1 and ERCS = 1) In this state, the DCO and IRG are off and the reference clock is derived from the external reference clock, ICGERCLK. The output clock signal ICGOUT frequency is given by fICGERCLK / R. If an external clock source is used (REFS = 0), then the input frequency on the EXTAL pin can be anywhere in the range 0 MHz to 40 MHz. If a crystal or resonator is used (REFS = 1), then frequency range is either low for RANGE = 0 or high for RANGE = 1. 8.4.7 FLL Engaged, External Clock (FEE) Mode The FLL engaged external (FEE) mode is entered when any of the following conditions occur: • CLKS = 11 and ERCS and DCOS are both high. • The DCO stabilizes (DCOS = 1) while in SCM upon exiting the off state with CLKS = 11. In FEE mode, the reference clock is derived from the external reference clock ICGERCLK, and the FLL loop will attempt to lock the ICGDCLK frequency to the desired value, as selected by the MFD bits. To run in FEE mode, there must be a working 32 kHz–100 kHz or 2 MHz–10 MHz external clock source. The maximum external clock frequency is limited to 10 MHz in FEE mode to prevent over-clocking the DCO. The minimum multiplier for the FLL, from Table 8-13 is 4. Because 4 X 10 MHz is 40MHz, which is the operational limit of the DCO, the reference clock cannot be any faster than 10 MHz. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 141 Internal Clock Generator (S08ICGV4) 8.4.7.1 FLL Engaged External Unlocked FEE unlocked is entered when FEE is entered and the count error (∆n) output from the subtractor is greater than the maximum nunlock or less than the minimum nunlock, as required by the lock detector to detect the unlock condition. The ICG will remain in this state while the count error (∆n) is greater than the maximum nlock or less than the minimum nlock, as required by the lock detector to detect the lock condition. In this state, the pulse counter, subtractor, digital loop filter, and DCO form a closed loop and attempt to lock it according to their operational descriptions later in this section. Upon entering this state and until the FLL becomes locked, the output clock signal ICGOUT frequency is given by fICGDCLK / (2×R) This extra divide by two prevents frequency overshoots during the initial locking process from exceeding chip-level maximum frequency specifications. After the FLL has locked, if an unexpected loss of lock causes it to re-enter the unlocked state while the ICG remains in FEE mode, the output clock signal ICGOUT frequency is given by fICGDCLK / R. 8.4.7.2 FLL Engaged External Locked FEE locked is entered from FEE unlocked when the count error (∆n) is less than nlock (max) and greater than nlock (min) for a given number of samples, as required by the lock detector to detect the lock condition. The output clock signal ICGOUT frequency is given by fICGDCLK/R. In FLL engaged external locked, the filter value is updated only once every four comparison cycles. The update made is an average of the error measurements taken in the four previous comparisons. 8.4.8 FLL Lock and Loss-of-Lock Detection To determine the FLL locked and loss-of-lock conditions, the pulse counter counts the pulses of the DCO for one comparison cycle (see Table 8-10 for explanation of a comparison cycle) and passes this number to the subtractor. The subtractor compares this value to the value in MFD and produces a count error, ∆n. To achieve locked status, ∆n must be between nlock (min) and nlock (max). After the FLL has locked, ∆n must stay between nunlock (min) and nunlock (max) to remain locked. If ∆n goes outside this range unexpectedly, the LOLS status bit is set and remains set until cleared by software or until the MCU is reset. LOLS is cleared by reading ICGS1 then writing 1 to ICGIF (LOLRE = 0), or by a loss-of-lock induced reset (LOLRE = 1), or by any MCU reset. If the ICG enters the off state due to stop mode when ENBDM = OSCSTEN = 0, the FLL loses locked status (LOCK is cleared), but LOLS remains unchanged because this is not an unexpected loss-of-lock condition. Though it would be unusual, if ENBDM is cleared to 0 while the MCU is in stop, the ICG enters the off state. Because this is an unexpected stopping of clocks, LOLS will be set when the MCU wakes up from stop. Expected loss of lock occurs when the MFD or CLKS bits are changed or in FEI mode only, when the TRIM bits are changed. In these cases, the LOCK bit will be cleared until the FLL regains lock, but the LOLS will not be set. MC9S08AW60 Data Sheet, Rev.1.0 142 Freescale Semiconductor Internal Clock Generator (S08ICGV4) 8.4.9 FLL Loss-of-Clock Detection The reference clock and the DCO clock are monitored under different conditions (see Table 8-9). Provided the reference frequency is being monitored, ERCS = 1 indicates that the reference clock meets minimum frequency requirements. When the reference and/or DCO clock(s) are being monitored, if either one falls below a certain frequency, fLOR and fLOD, respectively, the LOCS status bit will be set to indicate the error. LOCS will remain set until it is acknowledged or until the MCU is reset. LOCS is cleared by reading ICGS1 then writing 1 to ICGIF (LOCRE = 0), or by a loss-of-clock induced reset (LOCRE = 1), or by any MCU reset. If the ICG is in FEE, a loss of reference clock causes the ICG to enter SCM, and a loss of DCO clock causes the ICG to enter FBE mode. If the ICG is in FBE mode, a loss of reference clock will cause the ICG to enter SCM. In each case, the CLKST and CLKS bits will be automatically changed to reflect the new state. If the ICG is in FEE mode when a loss of clock occurs and the ERCS is still set to 1, then the CLKST bits are set to 10 and the ICG reverts to FBE mode. A loss of clock will also cause a loss of lock when in FEE or FEI modes. Because the method of clearing the LOCS and LOLS bits is the same, this would only be an issue in the unlikely case that LOLRE = 1 and LOCRE = 0. In this case, the interrupt would be overridden by the reset for the loss of lock. Table 8-9. Clock Monitoring (When LOCD = 0) Mode CLKS REFST ERCS External Reference Clock Monitored? DCO Clock Monitored? Off 0X or 11 X Forced Low No No 10 0 Forced Low No No 10 1 Real-Time1 Yes(1) No 0X X Forced Low No Yes2 10 0 Forced High No Yes(2) 10 1 Real-Time Yes Yes(2) 11 X Real-Time Yes Yes(2) FEI (CLKST = 01) 0X X Forced Low No Yes 11 X Real-Time Yes Yes FBE (CLKST = 10) 10 0 Forced High No No 10 1 Real-Time Yes No FEE (CLKST = 11) 11 X Real-Time Yes Yes SCM (CLKST = 00) 1 2 If ENABLE is high (waiting for external crystal start-up after exiting stop). DCO clock will not be monitored until DCOS = 1 upon entering SCM from off or FLL bypassed external mode. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 143 Internal Clock Generator (S08ICGV4) 8.4.10 Clock Mode Requirements A clock mode is requested by writing to CLKS1:CLKS0 and the actual clock mode is indicated by CLKST1:CLKST0. Provided minimum conditions are met, the status shown in CLKST1:CLKST0 should be the same as the requested mode in CLKS1:CLKS0. Table 8-10 shows the relationship between CLKS, CLKST, and ICGOUT. It also shows the conditions for CLKS = CLKST or the reason CLKS ≠ CLKST. NOTE If a crystal will be used before the next reset, then be sure to set REFS = 1 and CLKS = 1x on the first write to the ICGC1 register. Failure to do so will result in “locking” REFS = 0 which will prevent the oscillator amplifier from being enabled until the next reset occurs. Table 8-10. ICG State Table Actual Mode (CLKST) Off (XX) SCM (00) FEI (01) FBE (10) FEE (11) Desired Mode (CLKS) Range Reference Frequency (fREFERENCE) Comparison Cycle Time ICGOUT Conditions1 for CLKS = CLKST Reason CLKS1 ≠ CLKST Off (XX) X 0 — 0 — — FBE (10) X 0 — 0 — ERCS = 0 SCM (00) X fICGIRCLK/72 8/fICGIRCLK ICGDCLK/R Not switching from FBE to SCM — FEI (01) 0 fICGIRCLK/7(1) 8/fICGIRCLK ICGDCLK/R — DCOS = 0 FBE (10) X fICGIRCLK/7(1) 8/fICGIRCLK ICGDCLK/R — ERCS = 0 FEE (11) X fICGIRCLK/7(1) 8/fICGIRCLK ICGDCLK/R — DCOS = 0 or ERCS = 0 FEI (01) 0 fICGIRCLK/7 8/fICGIRCLK ICGDCLK/R DCOS = 1 — FEE (11) X fICGIRCLK/7 8/fICGIRCLK ICGDCLK/R — ERCS = 0 FBE (10) X 0 — ICGERCLK/R ERCS = 1 — FEE (11) X 0 — ICGERCLK/R — LOCS = 1 & ERCS = 1 0 fICGERCLK 2/fICGERCLK ICGDCLK/R3 ERCS = 1 and DCOS = 1 — 1 fICGERCLK 128/fICGERCLK ICGDCLK/R(2) ERCS = 1 and DCOS = 1 — FEE (11) 1 CLKST will not update immediately after a write to CLKS. Several bus cycles are required before CLKST updates to the new value. 2 The reference frequency has no effect on ICGOUT in SCM, but the reference frequency is still used in making the comparisons that determine the DCOS bit 3 After initial LOCK; will be ICGDCLK/2R during initial locking process and while FLL is re-locking after the MFD bits are changed. MC9S08AW60 Data Sheet, Rev.1.0 144 Freescale Semiconductor Internal Clock Generator (S08ICGV4) 8.4.11 Fixed Frequency Clock The ICG provides a fixed frequency clock output, XCLK, for use by on-chip peripherals. This output is equal to the internal bus clock, BUSCLK, in all modes except FEE. In FEE mode, XCLK is equal to ICGERCLK ÷ 2 when the following conditions are met: • (P × N) ÷ R ≥ 4 where P is determined by RANGE (see Table 8-12), N and R are determined by MFD and RFD respectively (see Table 8-13). • LOCK = 1. If the above conditions are not true, then XCLK is equal to BUSCLK. When the ICG is in either FEI or SCM mode, XCLK is turned off. Any peripherals which can use XCLK as a clock source must not do so when the ICG is in FEI or SCM mode. 8.4.12 High Gain Oscillator The oscillator has the option of running in a high gain oscillator (HGO) mode, which improves the oscillator's resistance to EMC noise when running in FBE or FEE modes. This option is selected by writing a 1 to the HGO bit in the ICGC1 register. HGO is used with both the high and low range oscillators but is only valid when REFS = 1 in the ICGC1 register. When HGO = 0, the standard low-power oscillator is selected. This bit is writable only once after any reset. 8.5 8.5.1 Initialization/Application Information Introduction The section is intended to give some basic direction on which configuration a user would want to select when initializing the ICG. For some applications, the serial communication link may dictate the accuracy of the clock reference. For other applications, lowest power consumption may be the chief clock consideration. Still others may have lowest cost as the primary goal. The ICG allows great flexibility in choosing which is best for any application. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 145 Internal Clock Generator (S08ICGV4) Table 8-11. ICG Configuration Consideration Clock Reference Source = Internal 1 Clock Reference Source = External FLL Engaged FEI 4 MHz < fBus < 20 MHz. Medium power (will be less than FEE if oscillator range = high) Good clock accuracy (After IRG is trimmed) Lowest system cost (no external components required) IRG is on. DCO is on. 1 FEE 4 MHz < fBus < 20 MHz Medium power (will be less than FEI if oscillator range = low) High clock accuracy Medium/High system cost (crystal, resonator or external clock source required) IRG is off. DCO is on. FLL Bypassed SCM This mode is mainly provided for quick and reliable system startup. 3 MHz < fBus < 5 MHz (default). 3 MHz < fBus < 20 MHz (via filter bits). Medium power Poor accuracy. IRG is off. DCO is on and open loop. FBE fBus range ≤ 8 MHz when crystal or resonator is used. Lowest power Highest clock accuracy Medium/High system cost (Crystal, resonator or external clock source required) IRG is off. DCO is off. The IRG typically consumes 100 µA. The FLL and DCO typically consumes 0.5 to 2.5 mA, depending upon output frequency. For minimum power consumption and minimum jitter, choose N and R to be as small as possible. The following sections contain initialization examples for various configurations. NOTE Hexadecimal values designated by a preceding $, binary values designated by a preceding %, and decimal values have no preceding character. Important configuration information is repeated here for reference. Table 8-12. ICGOUT Frequency Calculation Options Clock Scheme SCM — self-clocked mode (FLL bypassed internal) FBE — FLL bypassed external FEI — FLL engaged internal FEE — FLL engaged external 1 fICGOUT1 P Note fICGDCLK / R NA Typical fICGOUT = 8 MHz immediately after reset fext / R NA (fIRG / 7)* 64 * N / R 64 fext * P * N / R Range = 0 ; P = 64 Range = 1; P = 1 Typical fIRG = 243 kHz Ensure that fICGDCLK, which is equal to fICGOUT * R, does not exceed fICGDCLKmax. Table 8-13. MFD and RFD Decode Table MFD Value Multiplication Factor (N) RFD Division Factor (R) 000 001 010 011 100 4 6 8 10 12 000 001 010 011 100 ÷1 ÷2 ÷4 ÷8 ÷16 MC9S08AW60 Data Sheet, Rev.1.0 146 Freescale Semiconductor Internal Clock Generator (S08ICGV4) Table 8-13. MFD and RFD Decode Table 101 110 111 8.5.2 14 16 18 101 110 111 ÷32 ÷64 ÷128 Example #1: External Crystal = 32 kHz, Bus Frequency = 4.19 MHz In this example, the FLL will be used (in FEE mode) to multiply the external 32 kHz oscillator up to 8.38 MHz to achieve 4.19 MHz bus frequency. After the MCU is released from reset, the ICG is in self-clocked mode (SCM) and supplies approximately 8 MHz on ICGOUT, which corresponds to a 4 MHz bus frequency (fBus). The clock scheme will be FLL engaged, external (FEE). So fICGOUT = fext * P * N / R ; P = 64, fext = 32 kHz Eqn. 8-1 N / R = 8.38 MHz /(32 kHz * 64) = 4 ; we can choose N = 4 and R =1 Eqn. 8-2 Solving for N / R gives: The values needed in each register to set up the desired operation are: ICGC1 = $38 (%00111000) Bit 7 Bit 6 Bit 5 Bits 4:3 Bit 2 Bit 1 Bit 0 HGO RANGE REFS CLKS OSCSTEN LOCD 0 0 1 11 0 0 0 Configures oscillator for low power Configures oscillator for low-frequency range; FLL prescale factor is 64 Oscillator using crystal or resonator is requested FLL engaged, external reference clock mode Oscillator disabled Loss-of-clock detection enabled Unimplemented or reserved, always reads zero ICGC2 = $00 (%00000000) Bit 7 Bits 6:4 Bit 3 Bits 2:0 LOLRE MFD LOCRE RFD 0 000 0 000 Generates an interrupt request on loss of lock Sets the MFD multiplication factor to 4 Generates an interrupt request on loss of clock Sets the RFD division factor to ÷1 ICGS1 = $xx This is read only except for clearing interrupt flag ICGS2 = $xx This is read only; should read DCOS = 1 before performing any time critical tasks ICGFLTLU/L = $xx Only needed in self-clocked mode; FLT will be adjusted by loop to give 8.38 MHz DCO clock Bits 15:12 unused 0000 MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 147 Internal Clock Generator (S08ICGV4) Bits 11:0 FLT No need for user initialization ICGTRM = $xx Bits 7:0 TRIM Only need to write when trimming internal oscillator; not used when external crystal is clock source Figure 8-14 shows flow charts for three conditions requiring ICG initialization. RESET INITIALIZE ICG ICGC1 = $38 ICGC2 = $00 CHECK FLL LOCK STATUS. LOCK = 1? QUICK RECOVERY FROM STOP MINIMUM CURRENT DRAW IN STOP RECOVERY FROM STOP OSCSTEN = 1 RECOVERY FROM STOP OSCSTEN = 0 CHECK FLL LOCK STATUS. LOCK = 1? NO CHECK FLL LOCK STATUS. LOCK = 1? NO YES YES NO CONTINUE CONTINUE YES CONTINUE NOTE: THIS WILL REQUIRE THE OSCILLATOR TO START AND STABILIZE. ACTUAL TIME IS DEPENDENT ON CRYSTAL /RESONATOR AND EXTERNAL CIRCUITRY. Figure 8-14. ICG Initialization for FEE in Example #1 MC9S08AW60 Data Sheet, Rev.1.0 148 Freescale Semiconductor Internal Clock Generator (S08ICGV4) 8.5.3 Example #2: External Crystal = 4 MHz, Bus Frequency = 20 MHz In this example, the FLL will be used (in FEE mode) to multiply the external 4 MHz oscillator up to 40-MHz to achieve 20 MHz bus frequency. After the MCU is released from reset, the ICG is in self-clocked mode (SCM) and supplies approximately 8 MHz on ICGOUT which corresponds to a 4 MHz bus frequency (fBus). During reset initialization software, the clock scheme will be set to FLL engaged, external (FEE). So fICGOUT = fext * P * N / R ; P = 1, fext = 4.00 MHz Eqn. 8-3 N / R = 40 MHz /(4 MHz * 1) = 10 ; We can choose N = 10 and R = 1 Eqn. 8-4 Solving for N / R gives: The values needed in each register to set up the desired operation are: ICGC1 = $78 Bit 7 Bit 6 Bit 5 Bits 4:3 Bit 2 Bit 1 Bit 0 HGO RANGE REFS CLKS OSCSTEN LOCD ICGC2 = $30 Bit 7 Bit 6:4 Bit 3 Bit 2:0 (%01111000) 0 1 1 11 0 0 0 Configures oscillator for low power Configures oscillator for high-frequency range; FLL prescale factor is 1 Requests an oscillator FLL engaged, external reference clock mode Disables the oscillator Loss-of-clock detection enabled Unimplemented or reserved, always reads zero (%00110000) LOLRE MFD LOCRE RFD 0 011 0 000 Generates an interrupt request on loss of lock Sets the MFD multiplication factor to 10 Generates an interrupt request on loss of clock Sets the RFD division factor to ÷1 ICGS1 = $xx This is read only except for clearing interrupt flag ICGS2 = $xx This is read only. Should read DCOS before performing any time critical tasks ICGFLTLU/L = $xx Not used in this example ICGTRM Not used in this example MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 149 Internal Clock Generator (S08ICGV4) RECOVERY FROM STOP RESET INITIALIZE ICG ICGC1 = $7A ICGC2 = $30 CHECK FLL LOCK STATUS LOCK = 1? YES SERVICE INTERRUPT SOURCE (fBus = 4 MHz) NO CHECK FLL LOCK STATUS LOCK = 1? NO YES CONTINUE CONTINUE Figure 8-15. ICG Initialization and Stop Recovery for Example #2 MC9S08AW60 Data Sheet, Rev.1.0 150 Freescale Semiconductor Internal Clock Generator (S08ICGV4) 8.5.4 Example #3: No External Crystal Connection, 5.4 MHz Bus Frequency In this example, the FLL will be used (in FEI mode) to multiply the internal 243 kHz (approximate) reference clock up to 10.8 MHz to achieve 5.4 MHz bus frequency. This system will also use the trim function to fine tune the frequency based on an external reference signal. After the MCU is released from reset, the ICG is in self-clocked mode (SCM) and supplies approximately 8 MHz on ICGOUT which corresponds to a 4 MHz bus frequency (fBus). The clock scheme will be FLL engaged, internal (FEI). So fICGOUT = (fIRG / 7) * P * N / R ; P = 64, fIRG = 243 kHz Eqn. 8-5 Solving for N / R gives: N / R = 10.8 MHz /(243/7 kHz * 64) = 4.86 ; We can choose N = 10 and R = 2. Eqn. 8-6 A trim procedure will be required to hone the frequency to exactly 5.4 MHz. An example of the trim procedure is shown in example #4. The values needed in each register to set up the desired operation are: ICGC1 = $28 (%00101000) Bit 7 HGO 0 Bit 6 RANGE 0 Bit 5 REFS 1 Bits 4:3 CLKS 01 Bit 2 OSCSTEN 0 Bit 1 LOCD 0 Bit 0 0 Configures oscillator for low power Configures oscillator for low-frequency range; FLL prescale factor is 64 Oscillator using crystal or resonator requested (bit is really a don’t care) FLL engaged, internal reference clock mode Disables the oscillator Loss-of-clock enabled Unimplemented or reserved, always reads zero ICGC2 = $31 (%00110001) Bit 7 LOLRE 0 Bit 6:4 MFD 011 Bit 3 LOCRE 0 Bit 2:0 RFD 001 Generates an interrupt request on loss of lock Sets the MFD multiplication factor to 10 Generates an interrupt request on loss of clock Sets the RFD division factor to ÷2 ICGS1 = $xx This is read only except for clearing interrupt flag ICGS2 = $xx This is read only; good idea to read this before performing time critical operations ICGFLTLU/L = $xx Not used in this example MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 151 Internal Clock Generator (S08ICGV4) ICGTRM = $xx Bit 7:0 TRIM Only need to write when trimming internal oscillator; done in separate operation (see example #4) RECOVERY FROM STOP RESET INITIALIZE ICG ICGC1 = $28 ICGC2 = $31 CHECK FLL LOCK STATUS. LOCK = 1? CHECK FLL LOCK STATUS. LOCK = 1? NO YES NO CONTINUE YES CONTINUE NOTE: THIS WILL REQUIRE THE INTERAL REFERENCE CLOCK TO START AND STABILIZE. Figure 8-16. ICG Initialization and Stop Recovery for Example #3 MC9S08AW60 Data Sheet, Rev.1.0 152 Freescale Semiconductor Internal Clock Generator (S08ICGV4) 8.5.5 Example #4: Internal Clock Generator Trim The internally generated clock source is guaranteed to have a period ± 25% of the nominal value. In some cases, this may be sufficient accuracy. For other applications that require a tight frequency tolerance, a trimming procedure is provided that will allow a very accurate source. This section outlines one example of trimming the internal oscillator. Many other possible trimming procedures are valid and can be used. Initial conditions: 1) Clock supplied from ATE has 500 µsec duty period 2) ICG configured for internal reference with 4 MHz bus START TRIM PROCEDURE ICGTRM = $80, n = 1 MEASURE INCOMING CLOCK WIDTH (COUNT = # OF BUS CLOCKS / 4) COUNT < EXPECTED = 500 (RUNNING TOO SLOW) . CASE STATEMENT COUNT = EXPECTED = 500 COUNT > EXPECTED = 500 (RUNNING TOO FAST) ICGTRM = ICGTRM - 128 / (2**n) (DECREASING ICGTRM INCREASES THE FREQUENCY) ICGTRM = ICGTRM + 128 / (2**n) (INCREASING ICGTRM DECREASES THE FREQUENCY) STORE ICGTRM VALUE IN NON-VOLATILE MEMORY CONTINUE n = n+1 YES IS n > 8? NO Figure 8-17. Trim Procedure In this particular case, the MCU has been attached to a PCB and the entire assembly is undergoing final test with automated test equipment. A separate signal or message is provided to the MCU operating under user provided software control. The MCU initiates a trim procedure as outlined in Figure 8-17 while the tester supplies a precision reference signal. If the intended bus frequency is near the maximum allowed for the device, it is recommended to trim using a reduction divisor (R) twice the final value. After the trim procedure is complete, the reduction divisor can be restored. This will prevent accidental overshoot of the maximum clock frequency. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 153 Internal Clock Generator (S08ICGV4) MC9S08AW60 Data Sheet, Rev.1.0 154 Freescale Semiconductor Chapter 9 Keyboard Interrupt (S08KBIV1) 9.1 Introduction The MC9S08AW60/48/32/16 has one KBI module with eight keyboard interrupt inputs that are shared with port D and port G pins. See Chapter 2, “Pins and Connections,” for more information about the logic and hardware aspects of these pins. 9.2 Keyboard Pin Sharing The KBI input KBIP7 shares a common pin with PTD7 and AD15. When KBIP7 is enabled the pin is forced to its input state regardless of the value of the associated port D data direction bit. The port D pullup enable is still used to control the pullup resistor and the pin state can be sensed through a read of the port D data register (this requires that bit 7 of the port D DDR is 0). In the case that the pin is enabled as an ADC input, both the PTD7 and KBIP7 functions are disabled, including the pullup resistor. The KBI input KBIP6 shares a common pin with PTD3 and AD11, and KBI input KBIP5 shares a common pin with PTD2 and AD10. The sharing of each of these inputs with port and ADC functions operates in the same way as described above for KBIP7. The KBI inputs KBIP4 – KBIP0 are shared on common pins with PTG4 – PTG0. These pins all operate in the same way as described above for KBIP7 except that none are shared with an ADC input. KBIP3 – KBIP0 are always falling-edge/low-level sensitive. KBIP7 – KBIP4 can be configured for rising-edge/high-level or for falling-edge/low-level sensitivity. When any of the inputs KBIP7 – KBIP0 are enabled and configured to detect rising edges/high levels, and the pin pullup is enabled through the corresponding port pullup enable bit for that pin, a pulldown resistor rather than a pullup resistor is enabled on the pin. Table 9-1. KBI and Parallel I/O Interaction 1 PTxPEn (Pull Enable) PTxDDn (Data Direction) KBIPEn (KBI Pin Enable) KBEDGn (KBI Edge Select) Pullup Pulldown 0 0 0 x1 disabled disabled 1 0 0 x enabled disabled x 1 0 x disabled disabled 1 x 1 0 enabled disabled 1 x 1 1 disabled enabled 0 x 1 x disabled disabled x = Don’t care MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 155 Chapter 9 Keyboard Interrupt (S08KBIV1) 9.3 Features The keyboard interrupt (KBI) module features include: • Four falling edge/low level sensitive • Four falling edge/low level or rising edge/high level sensitive • Choice of edge-only or edge-and-level sensitivity • Common interrupt flag and interrupt enable control • Capable of waking up the MCU from stop3, stop2, stop1, or wait mode MC9S08AW60 Data Sheet, Rev.1.0 156 Freescale Semiconductor HCS08 CORE BDC DEBUG MODULE (DBG) RTI COP IRQ LVD SERIAL COMMUNICATIONS INTERFACE MODULE (SCI2) IIC MODULE (IIC1) 10-BIT ANALOG-TO-DIGITAL CONVERTER (ADC1) TxD2 SDA1 SCL1 6-CHANNEL TIMER/PWM MODULE (TPM1) INTERNAL CLOCK GENERATOR (ICG) LOW-POWER OSCILLATOR SERIAL COMMUNICATIONS INTERFACE MODULE (SCI1) VOLTAGE REGULATOR 2-CHANNEL TIMER/PWM MODULE (TPM2) SPSCK1 MOSI1 PTE7/SPSCK1 MISO1 SS1 TPM1CLK TPM1CH5– TPM1CH0 RxD1 TxD1 PORT E USER RAM AW60/48/32 = 2048 BYTES AW16 = 1024 BYTES PTD7/AD1P15/KBI1P7 PTD6/AD1P14/TPM1CLK PTD5/AD1P13 PTD4/AD1P12/TPM2CLK PTD3/AD1P11/KBI1P6 PTD2/AD1P10/KBI1P5 PTD1/AD1P9 PTD0/AD1P8 8 8 AD1P15–AD1P8 USER FLASH (AW60 = 63,280 BYTES) (AW48 = 49,152 BYTES) (AW32 = 32,768 BYTES) (AW16 = 16,384 BYTES) SERIAL PERIPHERAL INTERFACE MODULE (SPI1) PTC6 PTC5/RxD2 PTC4 PTC3/TxD2 PTC2/MCLK PTC1/SDA1 PTC0/SCL1 RxD2 AD1P7–AD1P0 VSSAD VREFL VREFH 6 TPM2CLK PORT F VSS PTB7/AD1P7– PTB0/AD1P0 PORT C RESETS AND INTERRUPTS MODES OF OPERATION POWER MANAGEMENT VDDAD VDD 8 PORT D IRQ PTA7– PTA0 HCS08 SYSTEM CONTROL TPM2CH1–TPM2CH0 2 KBI1P7–KBI1P5 3 8-BIT KEYBOARD INTERRUPT MODULE (KBI1) KBI1P4–KBI1P0 EXTAL XTAL 5 NOTES: 1. Port pins are software configurable with pullup device if input port. 2. Pin contains software configurable pullup/pulldown device if IRQ is enabled (IRQPE = 1). Pulldown is enabled if rising edge detect is selected (IRQEDG = 1) 3. IRQ does not have a clamp diode to VDD. IRQ should not be driven above VDD. 4. Pin contains integrated pullup device. 5. Pins PTD7, PTD3, PTD2, and PTG4 contain both pullup and pulldown devices. Pulldown enabled when KBI is enabled (KBIPEn = 1) and rising edge is selected (KBEDGn = 1). PORT G RESET 8 CPU PORT B BKGD/MS PORT A Chapter 9 Keyboard Interrupt (S08KBIV1) PTE6/MOSI1 PTE5/MISO1 PTE4/SS1 PTE3/TPM1CH1 PTE2/TPM1CH0 PTE1/RxD1 PTE0/TxD1 PTF7 PTF6 PTF5/TPM2CH1 PTF4/TPM2CH0 PTF3/TPM1CH5 PTF2/TPM1CH4 PTF1/TPM1CH3 PTF0/TPM1CH2 PTG6/EXTAL PTG5/XTAL PTG4/KBI1P4 PTG3/KBI1P3 PTG2/KBI1P2 PTG1/KBI1P1 PTG0/KBI1P0 Figure 9-1. Block Diagram Highlighting KBI Module MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 157 Keyboard Interrupt (S08KBIV1) 9.3.1 KBI Block Diagram Figure 9-2 shows the block diagram for a KBI module. KBI1P0 KBIPE0 VDD KBIPE3 0 SYNCHRONIZER S KBIPE4 KEYBOARD INTERRUPT FF STOP STOP BYPASS KEYBOARD INTERRUPT REQUEST KBIMOD 1 0 KBF CK KBEDG4 KBI1Pn RESET D CLR Q 1 KBI1P4 BUSCLK KBACK KBI1P3 KBIE S KBIPEn KBEDGn Figure 9-2. KBI Block Diagram 9.4 Register Definition This section provides information about all registers and control bits associated with the KBI module. Refer to the direct-page register summary in the Memory chapter of this data sheet for the absolute address assignments for all KBI registers. This section refers to registers and control bits only by their names. A Freescale-provided equate or header file is used to translate these names into the appropriate absolute addresses. MC9S08AW60 Data Sheet, Rev.1.0 158 Freescale Semiconductor Keyboard Interrupt (S08KBIV1) 9.4.1 KBI Status and Control Register (KBI1SC) 7 6 5 4 KBEDG7 KBEDG6 KBEDG5 KBEDG4 R 3 2 KBF 0 W Reset 1 0 KBIE KBIMOD 0 0 KBACK 0 0 0 0 0 0 = Unimplemented or Reserved Figure 9-3. KBI Status and Control Register (KBI1SC) Table 9-2. KBI1SC Register Field Descriptions Field Description 7:4 Keyboard Edge Select for KBI Port Bits — Each of these read/write bits selects the polarity of the edges and/or KBEDG[7:4] levels that are recognized as trigger events on the corresponding KBI port pin when it is configured as a keyboard interrupt input (KBIPEn = 1). Also see the KBIMOD control bit, which determines whether the pin is sensitive to edges-only or edges and levels. 0 Falling edges/low levels 1 Rising edges/high levels 3 KBF Keyboard Interrupt Flag — This read-only status flag is set whenever the selected edge event has been detected on any of the enabled KBI port pins. This flag is cleared by writing a 1 to the KBACK control bit. The flag will remain set if KBIMOD = 1 to select edge-and-level operation and any enabled KBI port pin remains at the asserted level. KBF can be used as a software pollable flag (KBIE = 0) or it can generate a hardware interrupt request to the CPU (KBIE = 1). 0 No KBI interrupt pending 1 KBI interrupt pending 2 KBACK Keyboard Interrupt Acknowledge — This write-only bit (reads always return 0) is used to clear the KBF status flag by writing a 1 to KBACK. When KBIMOD = 1 to select edge-and-level operation and any enabled KBI port pin remains at the asserted level, KBF is being continuously set so writing 1 to KBACK does not clear the KBF flag. 1 KBIE Keyboard Interrupt Enable — This read/write control bit determines whether hardware interrupts are generated when the KBF status flag equals 1. When KBIE = 0, no hardware interrupts are generated, but KBF can still be used for software polling. 0 KBF does not generate hardware interrupts (use polling) 1 KBI hardware interrupt requested when KBF = 1 KBIMOD Keyboard Detection Mode — This read/write control bit selects either edge-only detection or edge-and-level detection. KBI port bits 3 through 0 can detect falling edges-only or falling edges and low levels. KBI port bits 7 through 4 can be configured to detect either: • Rising edges-only or rising edges and high levels (KBEDGn = 1) • Falling edges-only or falling edges and low levels (KBEDGn = 0) 0 Edge-only detection 1 Edge-and-level detection MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 159 Keyboard Interrupt (S08KBIV1) 9.4.2 KBI Pin Enable Register (KBI1PE) 7 6 5 4 3 2 1 0 KBIPE7 KBIPE6 KBIPE5 KBIPE4 KBIPE3 KBIPE2 KBIPE1 KBIPE0 0 0 0 0 0 0 0 0 R W Reset = Unimplemented or Reserved Figure 9-4. KBI Pin Enable Register (KBI1PE) Table 9-3. KBI1PE Register Field Descriptions Field Description 7:0 KBIPE[7:0] 9.5 9.5.1 Keyboard Pin Enable for KBI Port Bits — Each of these read/write bits selects whether the associated KBI port pin is enabled as a keyboard interrupt input or functions as a general-purpose I/O pin. 0 Bit n of KBI port is a general-purpose I/O pin not associated with the KBI 1 Bit n of KBI port enabled as a keyboard interrupt input Functional Description Pin Enables The KBIPEn control bits in the KBI1PE register allow a user to enable (KBIPEn = 1) any combination of KBI-related port pins to be connected to the KBI module. Pins corresponding to 0s in KBI1PE are general-purpose I/O pins that are not associated with the KBI module. 9.5.2 Edge and Level Sensitivity Synchronous logic is used to detect edges. Prior to detecting an edge, enabled keyboard inputs in a KBI module must be at the deasserted logic level. A falling edge is detected when an enabled keyboard input signal is seen as a logic 1 (the deasserted level) during one bus cycle and then a logic 0 (the asserted level) during the next cycle. A rising edge is detected when the input signal is seen as a logic 0 during one bus cycle and then a logic 1 during the next cycle. The KBIMOD control bit can be set to reconfigure the detection logic so that it detects edges and levels. In KBIMOD = 1 mode, the KBF status flag becomes set when an edge is detected (when one or more enabled pins change from the deasserted to the asserted level while all other enabled pins remain at their deasserted levels), but the flag is continuously set (and cannot be cleared) as long as any enabled keyboard input pin remains at the asserted level. When the MCU enters stop mode, the synchronous edge-detection logic is bypassed (because clocks are stopped). In stop mode, KBI inputs act as asynchronous level-sensitive inputs so they can wake the MCU from stop mode. MC9S08AW60 Data Sheet, Rev.1.0 160 Freescale Semiconductor Keyboard Interrupt (S08KBIV1) 9.5.3 KBI Interrupt Controls The KBF status flag becomes set (1) when an edge event has been detected on any KBI input pin. If KBIE = 1 in the KBI1SC register, a hardware interrupt will be requested whenever KBF = 1. The KBF flag is cleared by writing a 1 to the keyboard acknowledge (KBACK) bit. When KBIMOD = 0 (selecting edge-only operation), KBF is always cleared by writing 1 to KBACK. When KBIMOD = 1 (selecting edge-and-level operation), KBF cannot be cleared as long as any keyboard input is at its asserted level. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 161 Keyboard Interrupt (S08KBIV1) MC9S08AW60 Data Sheet, Rev.1.0 162 Freescale Semiconductor Chapter 10 Timer/PWM (S08TPMV2) 10.1 Introduction The MC9S08AW60/48/32/16 includes two independent timer/PWM (TPM) modules which support traditional input capture, output compare, or buffered edge-aligned pulse-width modulation (PWM) on each channel. A control bit in each TPM configures all channels in that timer to operate as center-aligned PWM functions. In each of these two TPMs, timing functions are based on a separate 16-bit counter with prescaler and modulo features to control frequency and range (period between overflows) of the time reference. This timing system is ideally suited for a wide range of control applications, and the center-aligned PWM capability on the 3-channel TPM extends the field of applications to motor control in small appliances. The use of the fixed system clock, XCLK, as the clock source for either of the TPM modules allows the TPM prescaler to run using the oscillator rate divided by two (ICGERCLK/2). This option is only available if the ICG is configured in FEE mode and the proper conditions are met (see Section 8.4.11, “Fixed Frequency Clock”). In all other ICG modes this selection is redundant because XCLK is the same as BUSCLK. 10.2 Features The timer system in the MC9S08AW60/48/32/16 includes a 6-channel TPM1 and a separate 2-channel TPM2. Timer system features include: • A total of eight channels: — Each channel may be input capture, output compare, or buffered edge-aligned PWM — Rising-edge, falling-edge, or any-edge input capture trigger — Set, clear, or toggle output compare action — Selectable polarity on PWM outputs • Each TPM may be configured for buffered, center-aligned pulse-width modulation (CPWM) on all channels • Clock source to prescaler for each TPM is independently selectable as bus clock, fixed system clock, or an external pin: — Prescale taps for divide by 1, 2, 4, 8, 16, 32, 64, or 128 — External clock inputs TPM1CLK for TPM1 and TPM2CLK for TPM2 (only available in 64-pin package) • 16-bit free-running or up/down (CPWM) count operation • 16-bit modulus register to control counter range • Timer system enable • One interrupt per channel plus a terminal count interrupt for each TPM module MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 163 HCS08 CORE BDC DEBUG MODULE (DBG) RTI COP IRQ LVD SERIAL COMMUNICATIONS INTERFACE MODULE (SCI2) IIC MODULE (IIC1) 10-BIT ANALOG-TO-DIGITAL CONVERTER (ADC1) TxD2 SDA1 SCL1 INTERNAL CLOCK GENERATOR (ICG) 6-CHANNEL TIMER/PWM MODULE (TPM1) LOW-POWER OSCILLATOR SERIAL COMMUNICATIONS INTERFACE MODULE (SCI1) VOLTAGE REGULATOR 2-CHANNEL TIMER/PWM MODULE (TPM2) SPSCK1 MOSI1 PTE7/SPSCK1 MISO1 SS1 TPM1CLK TPM1CH5– TPM1CH0 RxD1 TxD1 PORT E USER RAM AW60/48/32 = 2048 BYTES AW16 = 1024 BYTES PTD7/AD1P15/KBI1P7 PTD6/AD1P14/TPM1CLK PTD5/AD1P13 PTD4/AD1P12/TPM2CLK PTD3/AD1P11/KBI1P6 PTD2/AD1P10/KBI1P5 PTD1/AD1P9 PTD0/AD1P8 8 8 AD1P15–AD1P8 USER FLASH (AW60 = 63,280 BYTES) (AW48 = 49,152 BYTES) (AW32 = 32,768 BYTES) (AW16 = 16,384 BYTES) SERIAL PERIPHERAL INTERFACE MODULE (SPI1) PTC6 PTC5/RxD2 PTC4 PTC3/TxD2 PTC2/MCLK PTC1/SDA1 PTC0/SCL1 RxD2 AD1P7–AD1P0 VSSAD VREFL VREFH 6 TPM2CLK PORT F VSS PTB7/AD1P7– PTB0/AD1P0 PORT C RESETS AND INTERRUPTS MODES OF OPERATION POWER MANAGEMENT VDDAD VDD 8 PORT D IRQ PTA7– PTA0 HCS08 SYSTEM CONTROL TPM2CH1–TPM2CH0 2 KBI1P7–KBI1P5 3 8-BIT KEYBOARD INTERRUPT MODULE (KBI1) KBI1P4–KBI1P0 EXTAL XTAL 5 NOTES: 1. Port pins are software configurable with pullup device if input port. 2. Pin contains software configurable pullup/pulldown device if IRQ is enabled (IRQPE = 1). Pulldown is enabled if rising edge detect is selected (IRQEDG = 1) 3. IRQ does not have a clamp diode to VDD. IRQ should not be driven above VDD. 4. Pin contains integrated pullup device. 5. Pins PTD7, PTD3, PTD2, and PTG4 contain both pullup and pulldown devices. Pulldown enabled when KBI is enabled (KBIPEn = 1) and rising edge is selected (KBEDGn = 1). PORT G RESET 8 CPU PORT B BKGD/MS PORT A Chapter 10 Timer/PWM (S08TPMV2) PTE6/MOSI1 PTE5/MISO1 PTE4/SS1 PTE3/TPM1CH1 PTE2/TPM1CH0 PTE1/RxD1 PTE0/TxD1 PTF7 PTF6 PTF5/TPM2CH1 PTF4/TPM2CH0 PTF3/TPM1CH5 PTF2/TPM1CH4 PTF1/TPM1CH3 PTF0/TPM1CH2 PTG6/EXTAL PTG5/XTAL PTG4/KBI1P4 PTG3/KBI1P3 PTG2/KBI1P2 PTG1/KBI1P1 PTG0/KBI1P0 Figure 10-1. Block Diagram Highlighting the TPM Module MC9S08AW60 Data Sheet, Rev.1.0 164 Freescale Semiconductor Timer/Pulse-Width Modulator (S08TPMV2) 10.2.1 Block Diagram Figure 10-2 shows the structure of a TPM. Some MCUs include more than one TPM, with various numbers of channels. BUSCLK XCLK TPMxCLK SYNC CLOCK SOURCE SELECT OFF, BUS, XCLK, EXT CLKSB PRESCALE AND SELECT DIVIDE BY 1, 2, 4, 8, 16, 32, 64, or 128 PS2 CLKSA PS1 PS0 CPWMS MAIN 16-BIT COUNTER TOF COUNTER RESET INTERRUPT LOGIC TOIE 16-BIT COMPARATOR TPMxMODH:TPMxMODL CHANNEL 0 ELS0B ELS0A PORT LOGIC 16-BIT COMPARATOR TPMxC0VH:TPMxC0VL CH0F INTERRUPT LOGIC 16-BIT LATCH INTERNAL BUS CHANNEL 1 MS0B MS0A ELS1B ELS1A CH0IE PORT LOGIC 16-BIT COMPARATOR TPMxCH1 CH1F TPMxC1VH:TPMxC1VL INTERRUPT LOGIC 16-BIT LATCH MS1A ELSnB ELSnA ... ... MS1B CH1IE ... CHANNEL n TPMxCH0 PORT LOGIC 16-BIT COMPARATOR TPMxCnVH:TPMxCnVL TPMxCHn CHnF 16-BIT LATCH MSnB MSnA CHnIE INTERRUPT LOGIC Figure 10-2. TPM Block Diagram The central component of the TPM is the 16-bit counter that can operate as a free-running counter, a modulo counter, or an up-/down-counter when the TPM is configured for center-aligned PWM. The TPM counter (when operating in normal up-counting mode) provides the timing reference for the input capture, output compare, and edge-aligned PWM functions. The timer counter modulo registers, TPMxMODH:TPMxMODL, control the modulo value of the counter. (The values 0x0000 or 0xFFFF MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 165 Timer/Pulse-Width Modulator (S08TPMV2) effectively make the counter free running.) Software can read the counter value at any time without affecting the counting sequence. Any write to either byte of the TPMxCNT counter resets the counter regardless of the data value written. All TPM channels are programmable independently as input capture, output compare, or buffered edge-aligned PWM channels. 10.3 External Signal Description When any pin associated with the timer is configured as a timer input, a passive pullup can be enabled. After reset, the TPM modules are disabled and all pins default to general-purpose inputs with the passive pullups disabled. 10.3.1 External TPM Clock Sources When control bits CLKSB:CLKSA in the timer status and control register are set to 1:1, the prescaler and consequently the 16-bit counter for TPMx are driven by an external clock source, TPMxCLK, connected to an I/O pin. A synchronizer is needed between the external clock and the rest of the TPM. This synchronizer is clocked by the bus clock so the frequency of the external source must be less than one-half the frequency of the bus rate clock. The upper frequency limit for this external clock source is specified to be one-fourth the bus frequency to conservatively accommodate duty cycle and phase-locked loop (PLL) or frequency-locked loop (FLL) frequency jitter effects. On some devices the external clock input is shared with one of the TPM channels. When a TPM channel is shared as the external clock input, the associated TPM channel cannot use the pin. (The channel can still be used in output compare mode as a software timer.) Also, if one of the TPM channels is used as the external clock input, the corresponding ELSnB:ELSnA control bits must be set to 0:0 so the channel is not trying to use the same pin. 10.3.2 TPMxCHn — TPMx Channel n I/O Pins Each TPM channel is associated with an I/O pin on the MCU. The function of this pin depends on the configuration of the channel. In some cases, no pin function is needed so the pin reverts to being controlled by general-purpose I/O controls. When a timer has control of a port pin, the port data and data direction registers do not affect the related pin(s). See the Pins and Connections chapter for additional information about shared pin functions. 10.4 Register Definition The TPM includes: • An 8-bit status and control register (TPMxSC) • A 16-bit counter (TPMxCNTH:TPMxCNTL) • A 16-bit modulo register (TPMxMODH:TPMxMODL) Each timer channel has: • An 8-bit status and control register (TPMxCnSC) MC9S08AW60 Data Sheet, Rev.1.0 166 Freescale Semiconductor Timer/Pulse-Width Modulator (S08TPMV2) • A 16-bit channel value register (TPMxCnVH:TPMxCnVL) Refer to the direct-page register summary in the Memory chapter of this data sheet for the absolute address assignments for all TPM registers. This section refers to registers and control bits only by their names. A Freescale-provided equate or header file is used to translate these names into the appropriate absolute addresses. Some MCU systems have more than one TPM, so register names include placeholder characters to identify which TPM and which channel is being referenced. For example, TPMxCnSC refers to timer (TPM) x, channel n and TPM1C2SC is the status and control register for timer 1, channel 2. 10.4.1 Timer x Status and Control Register (TPMxSC) TPMxSC contains the overflow status flag and control bits that are used to configure the interrupt enable, TPM configuration, clock source, and prescale divisor. These controls relate to all channels within this timer module. 7 R 6 5 4 3 2 1 0 TOIE CPWMS CLKSB CLKSA PS2 PS1 PS0 0 0 0 0 0 0 0 TOF W Reset 0 = Unimplemented or Reserved Figure 10-3. Timer x Status and Control Register (TPMxSC) Table 10-1. TPMxSC Register Field Descriptions Field Description 7 TOF Timer Overflow Flag — This flag is set when the TPM counter changes to 0x0000 after reaching the modulo value programmed in the TPM counter modulo registers. When the TPM is configured for CPWM, TOF is set after the counter has reached the value in the modulo register, at the transition to the next lower count value. Clear TOF by reading the TPM status and control register when TOF is set and then writing a 0 to TOF. If another TPM overflow occurs before the clearing sequence is complete, the sequence is reset so TOF would remain set after the clear sequence was completed for the earlier TOF. Reset clears TOF. Writing a 1 to TOF has no effect. 0 TPM counter has not reached modulo value or overflow 1 TPM counter has overflowed 6 TOIE Timer Overflow Interrupt Enable — This read/write bit enables TPM overflow interrupts. If TOIE is set, an interrupt is generated when TOF equals 1. Reset clears TOIE. 0 TOF interrupts inhibited (use software polling) 1 TOF interrupts enabled 5 CPWMS Center-Aligned PWM Select — This read/write bit selects CPWM operating mode. Reset clears this bit so the TPM operates in up-counting mode for input capture, output compare, and edge-aligned PWM functions. Setting CPWMS reconfigures the TPM to operate in up-/down-counting mode for CPWM functions. Reset clears CPWMS. 0 All TPMx channels operate as input capture, output compare, or edge-aligned PWM mode as selected by the MSnB:MSnA control bits in each channel’s status and control register 1 All TPMx channels operate in center-aligned PWM mode MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 167 Timer/Pulse-Width Modulator (S08TPMV2) Table 10-1. TPMxSC Register Field Descriptions (continued) Field Description 4:3 CLKS[B:A] Clock Source Select — As shown in Table 10-2, this 2-bit field is used to disable the TPM system or select one of three clock sources to drive the counter prescaler. The external source and the XCLK are synchronized to the bus clock by an on-chip synchronization circuit. 2:0 PS[2:0] Prescale Divisor Select — This 3-bit field selects one of eight divisors for the TPM clock input as shown in Table 10-3. This prescaler is located after any clock source synchronization or clock source selection, so it affects whatever clock source is selected to drive the TPM system. Table 10-2. TPM Clock Source Selection CLKSB:CLKSA TPM Clock Source to Prescaler Input 0:0 No clock selected (TPMx disabled) 0:1 Bus rate clock (BUSCLK) 1:0 Fixed system clock (XCLK) 1:1 External source (TPMxCLK)1,2 1 The maximum frequency that is allowed as an external clock is one-fourth of the bus frequency. 2 If the external clock input is shared with channel n and is selected as the TPM clock source, the corresponding ELSnB:ELSnA control bits should be set to 0:0 so channel n does not try to use the same pin for a conflicting function. Table 10-3. Prescale Divisor Selection 10.4.2 PS2:PS1:PS0 TPM Clock Source Divided-By 0:0:0 1 0:0:1 2 0:1:0 4 0:1:1 8 1:0:0 16 1:0:1 32 1:1:0 64 1:1:1 128 Timer x Counter Registers (TPMxCNTH:TPMxCNTL) The two read-only TPM counter registers contain the high and low bytes of the value in the TPM counter. Reading either byte (TPMxCNTH or TPMxCNTL) latches the contents of both bytes into a buffer where they remain latched until the other byte is read. This allows coherent 16-bit reads in either order. The coherency mechanism is automatically restarted by an MCU reset, a write of any value to TPMxCNTH or TPMxCNTL, or any write to the timer status/control register (TPMxSC). MC9S08AW60 Data Sheet, Rev.1.0 168 Freescale Semiconductor Timer/Pulse-Width Modulator (S08TPMV2) Reset clears the TPM counter registers. R 7 6 5 4 3 2 1 0 Bit 15 14 13 12 11 10 9 Bit 8 0 0 W Reset Any write to TPMxCNTH clears the 16-bit counter. 0 0 0 0 0 0 Figure 10-4. Timer x Counter Register High (TPMxCNTH) R 7 6 5 4 3 2 1 0 Bit 7 6 5 4 3 2 1 Bit 0 0 0 W Reset Any write to TPMxCNTL clears the 16-bit counter. 0 0 0 0 0 0 Figure 10-5. Timer x Counter Register Low (TPMxCNTL) When background mode is active, the timer counter and the coherency mechanism are frozen such that the buffer latches remain in the state they were in when the background mode became active even if one or both bytes of the counter are read while background mode is active. 10.4.3 Timer x Counter Modulo Registers (TPMxMODH:TPMxMODL) The read/write TPM modulo registers contain the modulo value for the TPM counter. After the TPM counter reaches the modulo value, the TPM counter resumes counting from 0x0000 at the next clock (CPWMS = 0) or starts counting down (CPWMS = 1), and the overflow flag (TOF) becomes set. Writing to TPMxMODH or TPMxMODL inhibits TOF and overflow interrupts until the other byte is written. Reset sets the TPM counter modulo registers to 0x0000, which results in a free-running timer counter (modulo disabled). 7 6 5 4 3 2 1 0 Bit 15 14 13 12 11 10 9 Bit 8 0 0 0 0 0 0 0 0 R W Reset Figure 10-6. Timer x Counter Modulo Register High (TPMxMODH) 7 6 5 4 3 2 1 0 Bit 7 6 5 4 3 2 1 Bit 0 0 0 0 0 0 0 0 0 R W Reset Figure 10-7. Timer x Counter Modulo Register Low (TPMxMODL) It is good practice to wait for an overflow interrupt so both bytes of the modulo register can be written well before a new overflow. An alternative approach is to reset the TPM counter before writing to the TPM modulo registers to avoid confusion about when the first counter overflow will occur. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 169 Timer/Pulse-Width Modulator (S08TPMV2) 10.4.4 Timer x Channel n Status and Control Register (TPMxCnSC) TPMxCnSC contains the channel interrupt status flag and control bits that are used to configure the interrupt enable, channel configuration, and pin function. 7 6 5 4 3 2 CHnF CHnIE MSnB MSnA ELSnB ELSnA 0 0 0 0 0 0 R 1 0 0 0 0 0 W Reset = Unimplemented or Reserved Figure 10-8. Timer x Channel n Status and Control Register (TPMxCnSC) Table 10-4. TPMxCnSC Register Field Descriptions Field Description 7 CHnF Channel n Flag — When channel n is configured for input capture, this flag bit is set when an active edge occurs on the channel n pin. When channel n is an output compare or edge-aligned PWM channel, CHnF is set when the value in the TPM counter registers matches the value in the TPM channel n value registers. This flag is seldom used with center-aligned PWMs because it is set every time the counter matches the channel value register, which correspond to both edges of the active duty cycle period. A corresponding interrupt is requested when CHnF is set and interrupts are enabled (CHnIE = 1). Clear CHnF by reading TPMxCnSC while CHnF is set and then writing a 0 to CHnF. If another interrupt request occurs before the clearing sequence is complete, the sequence is reset so CHnF would remain set after the clear sequence was completed for the earlier CHnF. This is done so a CHnF interrupt request cannot be lost by clearing a previous CHnF. Reset clears CHnF. Writing a 1 to CHnF has no effect. 0 No input capture or output compare event occurred on channel n 1 Input capture or output compare event occurred on channel n 6 CHnIE Channel n Interrupt Enable — This read/write bit enables interrupts from channel n. Reset clears CHnIE. 0 Channel n interrupt requests disabled (use software polling) 1 Channel n interrupt requests enabled 5 MSnB Mode Select B for TPM Channel n — When CPWMS = 0, MSnB = 1 configures TPM channel n for edge-aligned PWM mode. For a summary of channel mode and setup controls, refer to Table 10-5. 4 MSnA Mode Select A for TPM Channel n — When CPWMS = 0 and MSnB = 0, MSnA configures TPM channel n for input capture mode or output compare mode. Refer to Table 10-5 for a summary of channel mode and setup controls. 3:2 ELSn[B:A] Edge/Level Select Bits — Depending on the operating mode for the timer channel as set by CPWMS:MSnB:MSnA and shown in Table 10-5, these bits select the polarity of the input edge that triggers an input capture event, select the level that will be driven in response to an output compare match, or select the polarity of the PWM output. Setting ELSnB:ELSnA to 0:0 configures the related timer pin as a general-purpose I/O pin unrelated to any timer channel functions. This function is typically used to temporarily disable an input capture channel or to make the timer pin available as a general-purpose I/O pin when the associated timer channel is set up as a software timer that does not require the use of a pin. This is also the setting required for channel 0 when the TPMxCH0 pin is used as an external clock input. MC9S08AW60 Data Sheet, Rev.1.0 170 Freescale Semiconductor Timer/Pulse-Width Modulator (S08TPMV2) Table 10-5. Mode, Edge, and Level Selection CPWMS MSnB:MSnA ELSnB:ELSnA X XX 00 0 00 01 01 Input capture Capture on falling edge only 11 Capture on rising or falling edge Output compare Software compare only Toggle output on compare 10 Clear output on compare 11 Set output on compare 10 Edge-aligned PWM X1 XX Capture on rising edge only 10 01 1 Configuration Pin not used for TPM channel; use as an external clock for the TPM or revert to general-purpose I/O 00 1X Mode 10 Center-aligned PWM X1 High-true pulses (clear output on compare) Low-true pulses (set output on compare) High-true pulses (clear output on compare-up) Low-true pulses (set output on compare-up) If the associated port pin is not stable for at least two bus clock cycles before changing to input capture mode, it is possible to get an unexpected indication of an edge trigger. Typically, a program would clear status flags after changing channel configuration bits and before enabling channel interrupts or using the status flags to avoid any unexpected behavior. 10.4.5 Timer x Channel Value Registers (TPMxCnVH:TPMxCnVL) These read/write registers contain the captured TPM counter value of the input capture function or the output compare value for the output compare or PWM functions. The channel value registers are cleared by reset. 7 6 5 4 3 2 1 0 Bit 15 14 13 12 11 10 9 Bit 8 0 0 0 0 0 0 0 0 R W Reset Figure 10-9. Timer x Channel Value Register High (TPMxCnVH) 7 6 5 4 3 2 1 0 Bit 7 6 5 4 3 2 1 Bit 0 0 0 0 0 0 0 0 0 R W Reset Figure 10-10. Timer Channel Value Register Low (TPMxCnVL) In input capture mode, reading either byte (TPMxCnVH or TPMxCnVL) latches the contents of both bytes into a buffer where they remain latched until the other byte is read. This latching mechanism also resets (becomes unlatched) when the TPMxCnSC register is written. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 171 Timer/Pulse-Width Modulator (S08TPMV2) In output compare or PWM modes, writing to either byte (TPMxCnVH or TPMxCnVL) latches the value into a buffer. When both bytes have been written, they are transferred as a coherent 16-bit value into the timer channel value registers. This latching mechanism may be manually reset by writing to the TPMxCnSC register. This latching mechanism allows coherent 16-bit writes in either order, which is friendly to various compiler implementations. 10.5 Functional Description All TPM functions are associated with a main 16-bit counter that allows flexible selection of the clock source and prescale divisor. A 16-bit modulo register also is associated with the main 16-bit counter in the TPM. Each TPM channel is optionally associated with an MCU pin and a maskable interrupt function. The TPM has center-aligned PWM capabilities controlled by the CPWMS control bit in TPMxSC. When CPWMS is set to 1, timer counter TPMxCNT changes to an up-/down-counter and all channels in the associated TPM act as center-aligned PWM channels. When CPWMS = 0, each channel can independently be configured to operate in input capture, output compare, or buffered edge-aligned PWM mode. The following sections describe the main 16-bit counter and each of the timer operating modes (input capture, output compare, edge-aligned PWM, and center-aligned PWM). Because details of pin operation and interrupt activity depend on the operating mode, these topics are covered in the associated mode sections. 10.5.1 Counter All timer functions are based on the main 16-bit counter (TPMxCNTH:TPMxCNTL). This section discusses selection of the clock source, up-counting vs. up-/down-counting, end-of-count overflow, and manual counter reset. After any MCU reset, CLKSB:CLKSA = 0:0 so no clock source is selected and the TPM is inactive. Normally, CLKSB:CLKSA would be set to 0:1 so the bus clock drives the timer counter. The clock source for each of the TPM can be independently selected to be off, the bus clock (BUSCLK), the fixed system clock (XCLK), or an external input. The maximum frequency allowed for the external clock option is one-fourth the bus rate. Refer to Section 10.4.1, “Timer x Status and Control Register (TPMxSC)” and Table 10-2 for more information about clock source selection. When the microcontroller is in active background mode, the TPM temporarily suspends all counting until the microcontroller returns to normal user operating mode. During stop mode, all TPM clocks are stopped; therefore, the TPM is effectively disabled until clocks resume. During wait mode, the TPM continues to operate normally. The main 16-bit counter has two counting modes. When center-aligned PWM is selected (CPWMS = 1), the counter operates in up-/down-counting mode. Otherwise, the counter operates as a simple up-counter. As an up-counter, the main 16-bit counter counts from 0x0000 through its terminal count and then continues with 0x0000. The terminal count is 0xFFFF or a modulus value in TPMxMODH:TPMxMODL. MC9S08AW60 Data Sheet, Rev.1.0 172 Freescale Semiconductor Timer/Pulse-Width Modulator (S08TPMV2) When center-aligned PWM operation is specified, the counter counts upward from 0x0000 through its terminal count and then counts downward to 0x0000 where it returns to up-counting. Both 0x0000 and the terminal count value (value in TPMxMODH:TPMxMODL) are normal length counts (one timer clock period long). An interrupt flag and enable are associated with the main 16-bit counter. The timer overflow flag (TOF) is a software-accessible indication that the timer counter has overflowed. The enable signal selects between software polling (TOIE = 0) where no hardware interrupt is generated, or interrupt-driven operation (TOIE = 1) where a static hardware interrupt is automatically generated whenever the TOF flag is 1. The conditions that cause TOF to become set depend on the counting mode (up or up/down). In up-counting mode, the main 16-bit counter counts from 0x0000 through 0xFFFF and overflows to 0x0000 on the next counting clock. TOF becomes set at the transition from 0xFFFF to 0x0000. When a modulus limit is set, TOF becomes set at the transition from the value set in the modulus register to 0x0000. When the main 16-bit counter is operating in up-/down-counting mode, the TOF flag gets set as the counter changes direction at the transition from the value set in the modulus register and the next lower count value. This corresponds to the end of a PWM period. (The 0x0000 count value corresponds to the center of a period.) Because the HCS08 MCU is an 8-bit architecture, a coherency mechanism is built into the timer counter for read operations. Whenever either byte of the counter is read (TPMxCNTH or TPMxCNTL), both bytes are captured into a buffer so when the other byte is read, the value will represent the other byte of the count at the time the first byte was read. The counter continues to count normally, but no new value can be read from either byte until both bytes of the old count have been read. The main timer counter can be reset manually at any time by writing any value to either byte of the timer count TPMxCNTH or TPMxCNTL. Resetting the counter in this manner also resets the coherency mechanism in case only one byte of the counter was read before resetting the count. 10.5.2 Channel Mode Selection Provided CPWMS = 0 (center-aligned PWM operation is not specified), the MSnB and MSnA control bits in the channel n status and control registers determine the basic mode of operation for the corresponding channel. Choices include input capture, output compare, and buffered edge-aligned PWM. 10.5.2.1 Input Capture Mode With the input capture function, the TPM can capture the time at which an external event occurs. When an active edge occurs on the pin of an input capture channel, the TPM latches the contents of the TPM counter into the channel value registers (TPMxCnVH:TPMxCnVL). Rising edges, falling edges, or any edge may be chosen as the active edge that triggers an input capture. When either byte of the 16-bit capture register is read, both bytes are latched into a buffer to support coherent 16-bit accesses regardless of order. The coherency sequence can be manually reset by writing to the channel status/control register (TPMxCnSC). An input capture event sets a flag bit (CHnF) that can optionally generate a CPU interrupt request. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 173 Timer/Pulse-Width Modulator (S08TPMV2) 10.5.2.2 Output Compare Mode With the output compare function, the TPM can generate timed pulses with programmable position, polarity, duration, and frequency. When the counter reaches the value in the channel value registers of an output compare channel, the TPM can set, clear, or toggle the channel pin. In output compare mode, values are transferred to the corresponding timer channel value registers only after both 8-bit bytes of a 16-bit register have been written. This coherency sequence can be manually reset by writing to the channel status/control register (TPMxCnSC). An output compare event sets a flag bit (CHnF) that can optionally generate a CPU interrupt request. 10.5.2.3 Edge-Aligned PWM Mode This type of PWM output uses the normal up-counting mode of the timer counter (CPWMS = 0) and can be used when other channels in the same TPM are configured for input capture or output compare functions. The period of this PWM signal is determined by the setting in the modulus register (TPMxMODH:TPMxMODL). The duty cycle is determined by the setting in the timer channel value register (TPMxCnVH:TPMxCnVL). The polarity of this PWM signal is determined by the setting in the ELSnA control bit. Duty cycle cases of 0 percent and 100 percent are possible. As Figure 10-11 shows, the output compare value in the TPM channel registers determines the pulse width (duty cycle) of the PWM signal. The time between the modulus overflow and the output compare is the pulse width. If ELSnA = 0, the counter overflow forces the PWM signal high and the output compare forces the PWM signal low. If ELSnA = 1, the counter overflow forces the PWM signal low and the output compare forces the PWM signal high. OVERFLOW OVERFLOW OVERFLOW PERIOD PULSE WIDTH TPMxC OUTPUT COMPARE OUTPUT COMPARE OUTPUT COMPARE Figure 10-11. PWM Period and Pulse Width (ELSnA = 0) When the channel value register is set to 0x0000, the duty cycle is 0 percent. By setting the timer channel value register (TPMxCnVH:TPMxCnVL) to a value greater than the modulus setting, 100% duty cycle can be achieved. This implies that the modulus setting must be less than 0xFFFF to get 100% duty cycle. Because the HCS08 is a family of 8-bit MCUs, the settings in the timer channel registers are buffered to ensure coherent 16-bit updates and to avoid unexpected PWM pulse widths. Writes to either register, TPMxCnVH or TPMxCnVL, write to buffer registers. In edge-PWM mode, values are transferred to the corresponding timer channel registers only after both 8-bit bytes of a 16-bit register have been written and the value in the TPMxCNTH:TPMxCNTL counter is 0x0000. (The new duty cycle does not take effect until the next full period.) MC9S08AW60 Data Sheet, Rev.1.0 174 Freescale Semiconductor Timer/Pulse-Width Modulator (S08TPMV2) 10.5.3 Center-Aligned PWM Mode This type of PWM output uses the up-/down-counting mode of the timer counter (CPWMS = 1). The output compare value in TPMxCnVH:TPMxCnVL determines the pulse width (duty cycle) of the PWM signal and the period is determined by the value in TPMxMODH:TPMxMODL. TPMxMODH:TPMxMODL should be kept in the range of 0x0001 to 0x7FFF because values outside this range can produce ambiguous results. ELSnA will determine the polarity of the CPWM output. pulse width = 2 x (TPMxCnVH:TPMxCnVL) Eqn. 10-1 period = 2 x (TPMxMODH:TPMxMODL); for TPMxMODH:TPMxMODL = 0x0001–0x7FFF Eqn. 10-2 If the channel value register TPMxCnVH:TPMxCnVL is zero or negative (bit 15 set), the duty cycle will be 0%. If TPMxCnVH:TPMxCnVL is a positive value (bit 15 clear) and is greater than the (nonzero) modulus setting, the duty cycle will be 100% because the duty cycle compare will never occur. This implies the usable range of periods set by the modulus register is 0x0001 through 0x7FFE (0x7FFF if generation of 100% duty cycle is not necessary). This is not a significant limitation because the resulting period is much longer than required for normal applications. TPMxMODH:TPMxMODL = 0x0000 is a special case that should not be used with center-aligned PWM mode. When CPWMS = 0, this case corresponds to the counter running free from 0x0000 through 0xFFFF, but when CPWMS = 1 the counter needs a valid match to the modulus register somewhere other than at 0x0000 in order to change directions from up-counting to down-counting. Figure 10-12 shows the output compare value in the TPM channel registers (multiplied by 2), which determines the pulse width (duty cycle) of the CPWM signal. If ELSnA = 0, the compare match while counting up forces the CPWM output signal low and a compare match while counting down forces the output high. The counter counts up until it reaches the modulo setting in TPMxMODH:TPMxMODL, then counts down until it reaches zero. This sets the period equal to two times TPMxMODH:TPMxMODL. COUNT = 0 COUNT = TPMxMODH:TPMx OUTPUT COMPARE (COUNT UP) OUTPUT COMPARE (COUNT DOWN) COUNT = TPMxMODH:TPMx TPM1C PULSE WIDTH 2x 2x PERIOD Figure 10-12. CPWM Period and Pulse Width (ELSnA = 0) Center-aligned PWM outputs typically produce less noise than edge-aligned PWMs because fewer I/O pin transitions are lined up at the same system clock edge. This type of PWM is also required for some types of motor drives. Because the HCS08 is a family of 8-bit MCUs, the settings in the timer channel registers are buffered to ensure coherent 16-bit updates and to avoid unexpected PWM pulse widths. Writes to any of the registers, TPMxMODH, TPMxMODL, TPMxCnVH, and TPMxCnVL, actually write to buffer registers. Values are MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 175 Timer/Pulse-Width Modulator (S08TPMV2) transferred to the corresponding timer channel registers only after both 8-bit bytes of a 16-bit register have been written and the timer counter overflows (reverses direction from up-counting to down-counting at the end of the terminal count in the modulus register). This TPMxCNT overflow requirement only applies to PWM channels, not output compares. Optionally, when TPMxCNTH:TPMxCNTL = TPMxMODH:TPMxMODL, the TPM can generate a TOF interrupt at the end of this count. The user can choose to reload any number of the PWM buffers, and they will all update simultaneously at the start of a new period. Writing to TPMxSC cancels any values written to TPMxMODH and/or TPMxMODL and resets the coherency mechanism for the modulo registers. Writing to TPMxCnSC cancels any values written to the channel value registers and resets the coherency mechanism for TPMxCnVH:TPMxCnVL. 10.6 TPM Interrupts The TPM generates an optional interrupt for the main counter overflow and an interrupt for each channel. The meaning of channel interrupts depends on the mode of operation for each channel. If the channel is configured for input capture, the interrupt flag is set each time the selected input capture edge is recognized. If the channel is configured for output compare or PWM modes, the interrupt flag is set each time the main timer counter matches the value in the 16-bit channel value register. See the Resets, Interrupts, and System Configuration chapter for absolute interrupt vector addresses, priority, and local interrupt mask control bits. For each interrupt source in the TPM, a flag bit is set on recognition of the interrupt condition such as timer overflow, channel input capture, or output compare events. This flag may be read (polled) by software to verify that the action has occurred, or an associated enable bit (TOIE or CHnIE) can be set to enable hardware interrupt generation. While the interrupt enable bit is set, a static interrupt will be generated whenever the associated interrupt flag equals 1. It is the responsibility of user software to perform a sequence of steps to clear the interrupt flag before returning from the interrupt service routine. 10.6.1 Clearing Timer Interrupt Flags TPM interrupt flags are cleared by a 2-step process that includes a read of the flag bit while it is set (1) followed by a write of 0 to the bit. If a new event is detected between these two steps, the sequence is reset and the interrupt flag remains set after the second step to avoid the possibility of missing the new event. 10.6.2 Timer Overflow Interrupt Description The conditions that cause TOF to become set depend on the counting mode (up or up/down). In up-counting mode, the 16-bit timer counter counts from 0x0000 through 0xFFFF and overflows to 0x0000 on the next counting clock. TOF becomes set at the transition from 0xFFFF to 0x0000. When a modulus limit is set, TOF becomes set at the transition from the value set in the modulus register to 0x0000. When the counter is operating in up-/down-counting mode, the TOF flag gets set as the counter changes direction at the transition from the value set in the modulus register and the next lower count value. This corresponds to the end of a PWM period. (The 0x0000 count value corresponds to the center of a period.) MC9S08AW60 Data Sheet, Rev.1.0 176 Freescale Semiconductor Timer/Pulse-Width Modulator (S08TPMV2) 10.6.3 Channel Event Interrupt Description The meaning of channel interrupts depends on the current mode of the channel (input capture, output compare, edge-aligned PWM, or center-aligned PWM). When a channel is configured as an input capture channel, the ELSnB:ELSnA control bits select rising edges, falling edges, any edge, or no edge (off) as the edge that triggers an input capture event. When the selected edge is detected, the interrupt flag is set. The flag is cleared by the 2-step sequence described in Section 10.6.1, “Clearing Timer Interrupt Flags.” When a channel is configured as an output compare channel, the interrupt flag is set each time the main timer counter matches the 16-bit value in the channel value register. The flag is cleared by the 2-step sequence described in Section 10.6.1, “Clearing Timer Interrupt Flags.” 10.6.4 PWM End-of-Duty-Cycle Events For channels that are configured for PWM operation, there are two possibilities: • When the channel is configured for edge-aligned PWM, the channel flag is set when the timer counter matches the channel value register that marks the end of the active duty cycle period. • When the channel is configured for center-aligned PWM, the timer count matches the channel value register twice during each PWM cycle. In this CPWM case, the channel flag is set at the start and at the end of the active duty cycle, which are the times when the timer counter matches the channel value register. The flag is cleared by the 2-step sequence described in Section 10.6.1, “Clearing Timer Interrupt Flags.” MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 177 Timer/Pulse-Width Modulator (S08TPMV2) MC9S08AW60 Data Sheet, Rev.1.0 178 Freescale Semiconductor Chapter 11 Serial Communications Interface (S08SCIV2) 11.1 Introduction The MC9S08AW60/48/32/16 includes two independent serial communications interface (SCI) modules which are sometimes called universal asynchronous receiver/transmitters (UARTs). Typically, these systems are used to connect to the RS232 serial input/output (I/O) port of a personal computer or workstation, but they can also be used to communicate with other embedded controllers. A flexible, 13-bit, modulo-based baud rate generator supports a broad range of standard baud rates beyond 115.2 kbaud. Transmit and receive within the same SCI use a common baud rate, and each SCI module has a separate baud rate generator. This SCI system offers many advanced features not commonly found on other asynchronous serial I/O peripherals on other embedded controllers. The receiver employs an advanced data sampling technique that ensures reliable communication and noise detection. Hardware parity, receiver wakeup, and double buffering on transmit and receive are also included. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 179 HCS08 CORE BDC DEBUG MODULE (DBG) RTI COP IRQ LVD SERIAL COMMUNICATIONS INTERFACE MODULE (SCI2) IIC MODULE (IIC1) 10-BIT ANALOG-TO-DIGITAL CONVERTER (ADC1) TxD2 SDA1 SCL1 INTERNAL CLOCK GENERATOR (ICG) 6-CHANNEL TIMER/PWM MODULE (TPM1) LOW-POWER OSCILLATOR SERIAL COMMUNICATIONS INTERFACE MODULE (SCI1) VOLTAGE REGULATOR 2-CHANNEL TIMER/PWM MODULE (TPM2) SPSCK1 MOSI1 PTE7/SPSCK1 MISO1 SS1 TPM1CLK TPM1CH5– TPM1CH0 RxD1 TxD1 PORT E USER RAM AW60/48/32 = 2048 BYTES AW16 = 1024 BYTES PTD7/AD1P15/KBI1P7 PTD6/AD1P14/TPM1CLK PTD5/AD1P13 PTD4/AD1P12/TPM2CLK PTD3/AD1P11/KBI1P6 PTD2/AD1P10/KBI1P5 PTD1/AD1P9 PTD0/AD1P8 8 8 AD1P15–AD1P8 USER FLASH (AW60 = 63,280 BYTES) (AW48 = 49,152 BYTES) (AW32 = 32,768 BYTES) (AW16 = 16,384 BYTES) SERIAL PERIPHERAL INTERFACE MODULE (SPI1) PTC6 PTC5/RxD2 PTC4 PTC3/TxD2 PTC2/MCLK PTC1/SDA1 PTC0/SCL1 RxD2 AD1P7–AD1P0 VSSAD VREFL VREFH 6 TPM2CLK PORT F VSS PTB7/AD1P7– PTB0/AD1P0 PORT C RESETS AND INTERRUPTS MODES OF OPERATION POWER MANAGEMENT VDDAD VDD 8 PORT D IRQ PTA7– PTA0 HCS08 SYSTEM CONTROL TPM2CH1–TPM2CH0 2 KBI1P7–KBI1P5 3 8-BIT KEYBOARD INTERRUPT MODULE (KBI1) KBI1P4–KBI1P0 EXTAL XTAL 5 NOTES: 1. Port pins are software configurable with pullup device if input port. 2. Pin contains software configurable pullup/pulldown device if IRQ is enabled (IRQPE = 1). Pulldown is enabled if rising edge detect is selected (IRQEDG = 1) 3. IRQ does not have a clamp diode to VDD. IRQ should not be driven above VDD. 4. Pin contains integrated pullup device. 5. Pins PTD7, PTD3, PTD2, and PTG4 contain both pullup and pulldown devices. Pulldown enabled when KBI is enabled (KBIPEn = 1) and rising edge is selected (KBEDGn = 1). PORT G RESET 8 CPU PORT B BKGD/MS PORT A Chapter 11 Serial Communications Interface (S08SCIV2) PTE6/MOSI1 PTE5/MISO1 PTE4/SS1 PTE3/TPM1CH1 PTE2/TPM1CH0 PTE1/RxD1 PTE0/TxD1 PTF7 PTF6 PTF5/TPM2CH1 PTF4/TPM2CH0 PTF3/TPM1CH5 PTF2/TPM1CH4 PTF1/TPM1CH3 PTF0/TPM1CH2 PTG6/EXTAL PTG5/XTAL PTG4/KBI1P4 PTG3/KBI1P3 PTG2/KBI1P2 PTG1/KBI1P1 PTG0/KBI1P0 Figure 11-1. Block Diagram Highlighting the SCI Modules MC9S08AW60 Data Sheet, Rev.1.0 180 Freescale Semiconductor Serial Communications Interface (S08SCIV3) 11.1.1 Features Features of SCI module include: • Full-duplex, standard non-return-to-zero (NRZ) format • Double-buffered transmitter and receiver with separate enables • Programmable baud rates (13-bit modulo divider) • Interrupt-driven or polled operation: — Transmit data register empty and transmission complete — Receive data register full — Receive overrun, parity error, framing error, and noise error — Idle receiver detect • Hardware parity generation and checking • Programmable 8-bit or 9-bit character length • Receiver wakeup by idle-line or address-mark • Optional 13-bit break character • Selectable transmitter output polarity 11.1.2 Modes of Operation See Section 11.3, “Functional Description,” for a detailed description of SCI operation in the different modes. • 8- and 9- bit data modes • Stop modes — SCI is halted during all stop modes • Loop mode • Single-wire mode MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 181 Serial Communications Interface (S08SCIV3) 11.1.3 Block Diagram Figure 11-2 shows the transmitter portion of the SCI. (Figure 11-3 shows the receiver portion of the SCI.) INTERNAL BUS (WRITE-ONLY) LOOPS SCID – Tx BUFFER 8 7 6 5 4 3 2 1 PT PREAMBLE (ALL 1s) PARITY GENERATION SHIFT ENABLE PE LOAD FROM SCIxD SHIFT DIRECTION T8 0 START TO RECEIVE DATA IN L TO TxD PIN LSB H 1 × BAUD RATE CLOCK 11-BIT TRANSMIT SHIFT REGISTER LOOP CONTROL TXINV BREAK (ALL 0s) STOP M RSRC SCI CONTROLS TxD TE SBK TRANSMIT CONTROL TXDIR TxD DIRECTION TO TxD PIN LOGIC BRK13 TDRE TIE TC Tx INTERRUPT REQUEST TCIE Figure 11-2. SCI Transmitter Block Diagram MC9S08AW60 Data Sheet, Rev.1.0 182 Freescale Semiconductor Serial Communications Interface (S08SCIV3) Figure 11-3 shows the receiver portion of the SCI. INTERNAL BUS (READ-ONLY) SCID – Rx BUFFER 16 × BAUD RATE CLOCK 11-BIT RECEIVE SHIFT REGISTER LOOPS RSRC SINGLE-WIRE LOOP CONTROL ALL 1s WAKE 8 7 6 5 MSB H DATA RECOVERY FROM RxD PIN 3 2 1 0 L SHIFT DIRECTION WAKEUP LOGIC ILT 4 START M LSB STOP DIVIDE BY 16 RWU FROM TRANSMITTER RDRF RIE IDLE Rx INTERRUPT REQUEST ILIE OR ORIE FE FEIE ERROR INTERRUPT REQUEST NF NEIE PE PT PARITY CHECKING PF PEIE Figure 11-3. SCI Receiver Block Diagram MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 183 Serial Communications Interface (S08SCIV3) 11.2 Register Definition The SCI has eight 8-bit registers to control baud rate, select SCI options, report SCI status, and for transmit/receive data. Refer to the direct-page register summary in the Memory chapter of this data sheet for the absolute address assignments for all SCI registers. This section refers to registers and control bits only by their names. A Freescale-provided equate or header file is used to translate these names into the appropriate absolute addresses. 11.2.1 SCI Baud Rate Registers (SCIxBDH, SCIxBHL) This pair of registers controls the prescale divisor for SCI baud rate generation. To update the 13-bit baud rate setting [SBR12:SBR0], first write to SCIxBDH to buffer the high half of the new value and then write to SCIxBDL. The working value in SCIxBDH does not change until SCIxBDL is written. SCIxBDL is reset to a non-zero value, so after reset the baud rate generator remains disabled until the first time the receiver or transmitter is enabled (RE or TE bits in SCIxC2 are written to 1). R 7 6 5 0 0 0 4 3 2 1 0 SBR12 SBR11 SBR10 SBR9 SBR8 0 0 0 0 0 W Reset 0 0 0 = Unimplemented or Reserved Figure 11-4. SCI Baud Rate Register (SCIxBDH) Table 11-1. SCIxBDH Register Field Descriptions Field Description 4:0 SBR[12:8] Baud Rate Modulo Divisor — These 13 bits are referred to collectively as BR, and they set the modulo divide rate for the SCI baud rate generator. When BR = 0, the SCI baud rate generator is disabled to reduce supply current. When BR = 1 to 8191, the SCI baud rate = BUSCLK/(16×BR). See also BR bits in Table 11-2. 7 6 5 4 3 2 1 0 SBR7 SBR6 SBR5 SBR4 SBR3 SBR2 SBR1 SBR0 0 0 0 0 0 1 0 0 R W Reset Figure 11-5. SCI Baud Rate Register (SCIxBDL) MC9S08AW60 Data Sheet, Rev.1.0 184 Freescale Semiconductor Serial Communications Interface (S08SCIV3) Table 11-2. SCIxBDL Register Field Descriptions Field Description 7:0 SBR[7:0] Baud Rate Modulo Divisor — These 13 bits are referred to collectively as BR, and they set the modulo divide rate for the SCI baud rate generator. When BR = 0, the SCI baud rate generator is disabled to reduce supply current. When BR = 1 to 8191, the SCI baud rate = BUSCLK/(16×BR). See also BR bits in Table 11-1. 11.2.2 SCI Control Register 1 (SCIxC1) This read/write register is used to control various optional features of the SCI system. 7 6 5 4 3 2 1 0 LOOPS SCISWAI RSRC M WAKE ILT PE PT 0 0 0 0 0 0 0 0 R W Reset Figure 11-6. SCI Control Register 1 (SCIxC1) Table 11-3. SCIxC1 Register Field Descriptions Field 7 LOOPS 6 SCISWAI 5 RSRC 4 M 3 WAKE 2 ILT Description Loop Mode Select — Selects between loop back modes and normal 2-pin full-duplex modes. When LOOPS = 1, the transmitter output is internally connected to the receiver input. 0 Normal operation — RxD and TxD use separate pins. 1 Loop mode or single-wire mode where transmitter outputs are internally connected to receiver input. (See RSRC bit.) RxD pin is not used by SCI. SCI Stops in Wait Mode 0 SCI clocks continue to run in wait mode so the SCI can be the source of an interrupt that wakes up the CPU. 1 SCI clocks freeze while CPU is in wait mode. Receiver Source Select — This bit has no meaning or effect unless the LOOPS bit is set to 1. When LOOPS = 1, the receiver input is internally connected to the TxD pin and RSRC determines whether this connection is also connected to the transmitter output. 0 Provided LOOPS = 1, RSRC = 0 selects internal loop back mode and the SCI does not use the RxD pins. 1 Single-wire SCI mode where the TxD pin is connected to the transmitter output and receiver input. 9-Bit or 8-Bit Mode Select 0 Normal — start + 8 data bits (LSB first) + stop. 1 Receiver and transmitter use 9-bit data characters start + 8 data bits (LSB first) + 9th data bit + stop. Receiver Wakeup Method Select — Refer to Section 11.3.3.2, “Receiver Wakeup Operation” for more information. 0 Idle-line wakeup. 1 Address-mark wakeup. Idle Line Type Select — Setting this bit to 1 ensures that the stop bit and logic 1 bits at the end of a character do not count toward the 10 or 11 bit times of the logic high level by the idle line detection logic. Refer to Section 11.3.3.2.1, “Idle-Line Wakeup” for more information. 0 Idle character bit count starts after start bit. 1 Idle character bit count starts after stop bit. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 185 Serial Communications Interface (S08SCIV3) Table 11-3. SCIxC1 Register Field Descriptions (continued) Field Description 1 PE Parity Enable — Enables hardware parity generation and checking. When parity is enabled, the most significant bit (MSB) of the data character (eighth or ninth data bit) is treated as the parity bit. 0 No hardware parity generation or checking. 1 Parity enabled. 0 PT Parity Type — Provided parity is enabled (PE = 1), this bit selects even or odd parity. Odd parity means the total number of 1s in the data character, including the parity bit, is odd. Even parity means the total number of 1s in the data character, including the parity bit, is even. 0 Even parity. 1 Odd parity. 11.2.3 SCI Control Register 2 (SCIxC2) This register can be read or written at any time. 7 6 5 4 3 2 1 0 TIE TCIE RIE ILIE TE RE RWU SBK 0 0 0 0 0 0 0 0 R W Reset Figure 11-7. SCI Control Register 2 (SCIxC2) Table 11-4. SCIxC2 Register Field Descriptions Field 7 TIE 6 TCIE Description Transmit Interrupt Enable (for TDRE) 0 Hardware interrupts from TDRE disabled (use polling). 1 Hardware interrupt requested when TDRE flag is 1. Transmission Complete Interrupt Enable (for TC) 0 Hardware interrupt requested when TC flag is 1. 1 Hardware interrupts from TC disabled (use polling). 5 RIE Receiver Interrupt Enable (for RDRF) 0 Hardware interrupts from RDRF disabled (use polling). 1 Hardware interrupt requested when RDRF flag is 1. 4 ILIE Idle Line Interrupt Enable (for IDLE) 0 Hardware interrupts from IDLE disabled (use polling). 1 Hardware interrupt requested when IDLE flag is 1. 3 TE Transmitter Enable 0 Transmitter off. 1 Transmitter on. TE must be 1 in order to use the SCI transmitter. Normally, when TE = 1, the SCI forces the TxD pin to act as an output for the SCI system. If LOOPS = 1 and RSRC = 0, the TxD pin reverts to being a port B general-purpose I/O pin even if TE = 1. When the SCI is configured for single-wire operation (LOOPS = RSRC = 1), TXDIR controls the direction of traffic on the single SCI communication line (TxD pin). TE also can be used to queue an idle character by writing TE = 0 then TE = 1 while a transmission is in progress. Refer to Section 11.3.2.1, “Send Break and Queued Idle,” for more details. When TE is written to 0, the transmitter keeps control of the port TxD pin until any data, queued idle, or queued break character finishes transmitting before allowing the pin to revert to a general-purpose I/O pin. MC9S08AW60 Data Sheet, Rev.1.0 186 Freescale Semiconductor Serial Communications Interface (S08SCIV3) Table 11-4. SCIxC2 Register Field Descriptions (continued) Field Description 2 RE Receiver Enable — When the SCI receiver is off, the RxD pin reverts to being a general-purpose port I/O pin. 0 Receiver off. 1 Receiver on. 1 RWU Receiver Wakeup Control — This bit can be written to 1 to place the SCI receiver in a standby state where it waits for automatic hardware detection of a selected wakeup condition. The wakeup condition is either an idle line between messages (WAKE = 0, idle-line wakeup), or a logic 1 in the most significant data bit in a character (WAKE = 1, address-mark wakeup). Application software sets RWU and (normally) a selected hardware condition automatically clears RWU. Refer to Section 11.3.3.2, “Receiver Wakeup Operation,” for more details. 0 Normal SCI receiver operation. 1 SCI receiver in standby waiting for wakeup condition. 0 SBK Send Break — Writing a 1 and then a 0 to SBK queues a break character in the transmit data stream. Additional break characters of 10 or 11 bit times of logic 0 are queued as long as SBK = 1. Depending on the timing of the set and clear of SBK relative to the information currently being transmitted, a second break character may be queued before software clears SBK. Refer to Section 11.3.2.1, “Send Break and Queued Idle,” for more details. 0 Normal transmitter operation. 1 Queue break character(s) to be sent. 11.2.4 SCI Status Register 1 (SCIxS1) This register has eight read-only status flags. Writes have no effect. Special software sequences (which do not involve writing to this register) are used to clear these status flags. R 7 6 5 4 3 2 1 0 TDRE TC RDRF IDLE OR NF FE PF 1 1 0 0 0 0 0 0 W Reset = Unimplemented or Reserved Figure 11-8. SCI Status Register 1 (SCIxS1) Table 11-5. SCIxS1 Register Field Descriptions Field Description 7 TDRE Transmit Data Register Empty Flag — TDRE is set out of reset and when a transmit data value transfers from the transmit data buffer to the transmit shifter, leaving room for a new character in the buffer. To clear TDRE, read SCIxS1 with TDRE = 1 and then write to the SCI data register (SCIxD). 0 Transmit data register (buffer) full. 1 Transmit data register (buffer) empty. 6 TC Transmission Complete Flag — TC is set out of reset and when TDRE = 1 and no data, preamble, or break character is being transmitted. 0 Transmitter active (sending data, a preamble, or a break). 1 Transmitter idle (transmission activity complete). TC is cleared automatically by reading SCIxS1 with TC = 1 and then doing one of the following three things: • Write to the SCI data register (SCIxD) to transmit new data • Queue a preamble by changing TE from 0 to 1 • Queue a break character by writing 1 to SBK in SCIxC2 MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 187 Serial Communications Interface (S08SCIV3) Table 11-5. SCIxS1 Register Field Descriptions (continued) Field Description 5 RDRF Receive Data Register Full Flag — RDRF becomes set when a character transfers from the receive shifter into the receive data register (SCIxD). To clear RDRF, read SCIxS1 with RDRF = 1 and then read the SCI data register (SCIxD). 0 Receive data register empty. 1 Receive data register full. 4 IDLE Idle Line Flag — IDLE is set when the SCI receive line becomes idle for a full character time after a period of activity. When ILT = 0, the receiver starts counting idle bit times after the start bit. So if the receive character is all 1s, these bit times and the stop bit time count toward the full character time of logic high (10 or 11 bit times depending on the M control bit) needed for the receiver to detect an idle line. When ILT = 1, the receiver doesn’t start counting idle bit times until after the stop bit. So the stop bit and any logic high bit times at the end of the previous character do not count toward the full character time of logic high needed for the receiver to detect an idle line. To clear IDLE, read SCIxS1 with IDLE = 1 and then read the SCI data register (SCIxD). After IDLE has been cleared, it cannot become set again until after a new character has been received and RDRF has been set. IDLE will get set only once even if the receive line remains idle for an extended period. 0 No idle line detected. 1 Idle line was detected. 3 OR Receiver Overrun Flag — OR is set when a new serial character is ready to be transferred to the receive data register (buffer), but the previously received character has not been read from SCIxD yet. In this case, the new character (and all associated error information) is lost because there is no room to move it into SCIxD. To clear OR, read SCIxS1 with OR = 1 and then read the SCI data register (SCIxD). 0 No overrun. 1 Receive overrun (new SCI data lost). 2 NF Noise Flag — The advanced sampling technique used in the receiver takes seven samples during the start bit and three samples in each data bit and the stop bit. If any of these samples disagrees with the rest of the samples within any bit time in the frame, the flag NF will be set at the same time as the flag RDRF gets set for the character. To clear NF, read SCIxS1 and then read the SCI data register (SCIxD). 0 No noise detected. 1 Noise detected in the received character in SCIxD. 1 FE Framing Error Flag — FE is set at the same time as RDRF when the receiver detects a logic 0 where the stop bit was expected. This suggests the receiver was not properly aligned to a character frame. To clear FE, read SCIxS1 with FE = 1 and then read the SCI data register (SCIxD). 0 No framing error detected. This does not guarantee the framing is correct. 1 Framing error. 0 PF Parity Error Flag — PF is set at the same time as RDRF when parity is enabled (PE = 1) and the parity bit in the received character does not agree with the expected parity value. To clear PF, read SCIxS1 and then read the SCI data register (SCIxD). 0 No parity error. 1 Parity error. MC9S08AW60 Data Sheet, Rev.1.0 188 Freescale Semiconductor Serial Communications Interface (S08SCIV3) 11.2.5 SCI Status Register 2 (SCIxS2) This register has one read-only status flag. Writes have no effect. R 7 6 5 4 3 0 0 0 0 0 2 1 0 0 RAF 0 0 BRK13 W Reset 0 0 0 0 0 0 = Unimplemented or Reserved Figure 11-9. SCI Status Register 2 (SCIxS2) Table 11-6. SCIxS2 Register Field Descriptions Field 2 BRK13 0 RAF 11.2.6 Description Break Character Length — BRK13 is used to select a longer break character length. Detection of a framing error is not affected by the state of this bit. 0 Break character is 10 bit times (11 if M = 1) 1 Break character is 13 bit times (14 if M = 1) Receiver Active Flag — RAF is set when the SCI receiver detects the beginning of a valid start bit, and RAF is cleared automatically when the receiver detects an idle line. This status flag can be used to check whether an SCI character is being received before instructing the MCU to go to stop mode. 0 SCI receiver idle waiting for a start bit. 1 SCI receiver active (RxD input not idle). SCI Control Register 3 (SCIxC3) 7 R 6 5 4 3 2 1 0 T8 TXDIR TXINV ORIE NEIE FEIE PEIE 0 0 0 0 0 0 0 R8 W Reset 0 = Unimplemented or Reserved Figure 11-10. SCI Control Register 3 (SCIxC3) Table 11-7. SCIxC3 Register Field Descriptions Field Description 7 R8 Ninth Data Bit for Receiver — When the SCI is configured for 9-bit data (M = 1), R8 can be thought of as a ninth receive data bit to the left of the MSB of the buffered data in the SCIxD register. When reading 9-bit data, read R8 before reading SCIxD because reading SCIxD completes automatic flag clearing sequences which could allow R8 and SCIxD to be overwritten with new data. 6 T8 Ninth Data Bit for Transmitter — When the SCI is configured for 9-bit data (M = 1), T8 may be thought of as a ninth transmit data bit to the left of the MSB of the data in the SCIxD register. When writing 9-bit data, the entire 9-bit value is transferred to the SCI shift register after SCIxD is written so T8 should be written (if it needs to change from its previous value) before SCIxD is written. If T8 does not need to change in the new value (such as when it is used to generate mark or space parity), it need not be written each time SCIxD is written. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 189 Serial Communications Interface (S08SCIV3) Table 11-7. SCIxC3 Register Field Descriptions (continued) Field 1 Description 5 TXDIR TxD Pin Direction in Single-Wire Mode — When the SCI is configured for single-wire half-duplex operation (LOOPS = RSRC = 1), this bit determines the direction of data at the TxD pin. 0 TxD pin is an input in single-wire mode. 1 TxD pin is an output in single-wire mode. 4 TXINV1 Transmit Data Inversion — Setting this bit reverses the polarity of the transmitted data output. 0 Transmit data not inverted 1 Transmit data inverted 3 ORIE Overrun Interrupt Enable — This bit enables the overrun flag (OR) to generate hardware interrupt requests. 0 OR interrupts disabled (use polling). 1 Hardware interrupt requested when OR = 1. 2 NEIE Noise Error Interrupt Enable — This bit enables the noise flag (NF) to generate hardware interrupt requests. 0 NF interrupts disabled (use polling). 1 Hardware interrupt requested when NF = 1. 1 FEIE Framing Error Interrupt Enable — This bit enables the framing error flag (FE) to generate hardware interrupt requests. 0 FE interrupts disabled (use polling). 1 Hardware interrupt requested when FE = 1. 0 PEIE Parity Error Interrupt Enable — This bit enables the parity error flag (PF) to generate hardware interrupt requests. 0 PF interrupts disabled (use polling). 1 Hardware interrupt requested when PF = 1. Setting TXINV inverts the TxD output for all cases: data bits, start and stop bits, break, and idle. 11.2.7 SCI Data Register (SCIxD) This register is actually two separate registers. Reads return the contents of the read-only receive data buffer and writes go to the write-only transmit data buffer. Reads and writes of this register are also involved in the automatic flag clearing mechanisms for the SCI status flags. 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 0 0 0 0 0 0 0 0 Reset Figure 11-11. SCI Data Register (SCIxD) MC9S08AW60 Data Sheet, Rev.1.0 190 Freescale Semiconductor Serial Communications Interface (S08SCIV3) 11.3 Functional Description The SCI allows full-duplex, asynchronous, NRZ serial communication among the MCU and remote devices, including other MCUs. The SCI comprises a baud rate generator, transmitter, and receiver block. The transmitter and receiver operate independently, although they use the same baud rate generator. During normal operation, the MCU monitors the status of the SCI, writes the data to be transmitted, and processes received data. The following describes each of the blocks of the SCI. 11.3.1 Baud Rate Generation As shown in Figure 11-12, the clock source for the SCI baud rate generator is the bus-rate clock. MODULO DIVIDE BY (1 THROUGH 8191) BUSCLK SBR12:SBR0 BAUD RATE GENERATOR OFF IF [SBR12:SBR0] = 0 DIVIDE BY 16 Tx BAUD RATE Rx SAMPLING CLOCK (16 × BAUD RATE) BAUD RATE = BUSCLK [SBR12:SBR0] × 16 Figure 11-12. SCI Baud Rate Generation SCI communications require the transmitter and receiver (which typically derive baud rates from independent clock sources) to use the same baud rate. Allowed tolerance on this baud frequency depends on the details of how the receiver synchronizes to the leading edge of the start bit and how bit sampling is performed. The MCU resynchronizes to bit boundaries on every high-to-low transition, but in the worst case, there are no such transitions in the full 10- or 11-bit time character frame so any mismatch in baud rate is accumulated for the whole character time. For a Freescale Semiconductor SCI system whose bus frequency is driven by a crystal, the allowed baud rate mismatch is about ±4.5 percent for 8-bit data format and about ±4 percent for 9-bit data format. Although baud rate modulo divider settings do not always produce baud rates that exactly match standard rates, it is normally possible to get within a few percent, which is acceptable for reliable communications. 11.3.2 Transmitter Functional Description This section describes the overall block diagram for the SCI transmitter, as well as specialized functions for sending break and idle characters. The transmitter block diagram is shown in Figure 11-2. The transmitter output (TxD) idle state defaults to logic high (TXINV = 0 following reset). The transmitter output is inverted by setting TXINV = 1. The transmitter is enabled by setting the TE bit in SCIxC2. This queues a preamble character that is one full character frame of the idle state. The transmitter then remains idle until data is available in the transmit data buffer. Programs store data into the transmit data buffer by writing to the SCI data register (SCIxD). The central element of the SCI transmitter is the transmit shift register that is either 10 or 11 bits long depending on the setting in the M control bit. For the remainder of this section, we will assume M = 0, MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 191 Serial Communications Interface (S08SCIV3) selecting the normal 8-bit data mode. In 8-bit data mode, the shift register holds a start bit, eight data bits, and a stop bit. When the transmit shift register is available for a new SCI character, the value waiting in the transmit data register is transferred to the shift register (synchronized with the baud rate clock) and the transmit data register empty (TDRE) status flag is set to indicate another character may be written to the transmit data buffer at SCIxD. If no new character is waiting in the transmit data buffer after a stop bit is shifted out the TxD1 pin, the transmitter sets the transmit complete flag and enters an idle mode, with TxD1 high, waiting for more characters to transmit. Writing 0 to TE does not immediately release the pin to be a general-purpose I/O pin. Any transmit activity that is in progress must first be completed. This includes data characters in progress, queued idle characters, and queued break characters. 11.3.2.1 Send Break and Queued Idle The SBK control bit in SCIxC2 is used to send break characters which were originally used to gain the attention of old teletype receivers. Break characters are a full character time of logic 0 (10 bit times including the start and stop bits). A longer break of 13 bit times can be enabled by setting BRK13 = 1. Normally, a program would wait for TDRE to become set to indicate the last character of a message has moved to the transmit shifter, then write 1 and then write 0 to the SBK bit. This action queues a break character to be sent as soon as the shifter is available. If SBK is still 1 when the queued break moves into the shifter (synchronized to the baud rate clock), an additional break character is queued. If the receiving device is another Freescale Semiconductor SCI, the break characters will be received as 0s in all eight data bits and a framing error (FE = 1) occurs. When idle-line wakeup is used, a full character time of idle (logic 1) is needed between messages to wake up any sleeping receivers. Normally, a program would wait for TDRE to become set to indicate the last character of a message has moved to the transmit shifter, then write 0 and then write 1 to the TE bit. This action queues an idle character to be sent as soon as the shifter is available. As long as the character in the shifter does not finish while TE = 0, the SCI transmitter never actually releases control of the TxD1 pin. If there is a possibility of the shifter finishing while TE = 0, set the general-purpose I/O controls so the pin that is shared with TxD1 is an output driving a logic 1. This ensures that the TxD1 line will look like a normal idle line even if the SCI loses control of the port pin between writing 0 and then 1 to TE. The length of the break character is affected by the BRK13 and M bits as shown below. Table 11-8. Break Character Length BRK13 M Break Character Length 0 0 10 bit times 0 1 11 bit times 1 0 13 bit times 1 1 14 bit times MC9S08AW60 Data Sheet, Rev.1.0 192 Freescale Semiconductor Serial Communications Interface (S08SCIV3) 11.3.3 Receiver Functional Description In this section, the receiver block diagram (Figure 11-3) is used as a guide for the overall receiver functional description. Next, the data sampling technique used to reconstruct receiver data is described in more detail. Finally, two variations of the receiver wakeup function are explained. The receiver is enabled by setting the RE bit in SCIxC2. Character frames consist of a start bit of logic 0, eight (or nine) data bits (LSB first), and a stop bit of logic 1. For information about 9-bit data mode, refer to Section 11.4.1, “8- and 9-Bit Data Modes.” For the remainder of this discussion, we assume the SCI is configured for normal 8-bit data mode. After receiving the stop bit into the receive shifter, and provided the receive data register is not already full, the data character is transferred to the receive data register and the receive data register full (RDRF) status flag is set. If RDRF was already set indicating the receive data register (buffer) was already full, the overrun (OR) status flag is set and the new data is lost. Because the SCI receiver is double-buffered, the program has one full character time after RDRF is set before the data in the receive data buffer must be read to avoid a receiver overrun. When a program detects that the receive data register is full (RDRF = 1), it gets the data from the receive data register by reading SCIxD. The RDRF flag is cleared automatically by a 2-step sequence which is normally satisfied in the course of the user’s program that handles receive data. Refer to Section 11.3.4, “Interrupts and Status Flags,” for more details about flag clearing. 11.3.3.1 Data Sampling Technique The SCI receiver uses a 16× baud rate clock for sampling. The receiver starts by taking logic level samples at 16 times the baud rate to search for a falling edge on the RxD1 serial data input pin. A falling edge is defined as a logic 0 sample after three consecutive logic 1 samples. The 16× baud rate clock is used to divide the bit time into 16 segments labeled RT1 through RT16. When a falling edge is located, three more samples are taken at RT3, RT5, and RT7 to make sure this was a real start bit and not merely noise. If at least two of these three samples are 0, the receiver assumes it is synchronized to a receive character. The receiver then samples each bit time, including the start and stop bits, at RT8, RT9, and RT10 to determine the logic level for that bit. The logic level is interpreted to be that of the majority of the samples taken during the bit time. In the case of the start bit, the bit is assumed to be 0 if at least two of the samples at RT3, RT5, and RT7 are 0 even if one or all of the samples taken at RT8, RT9, and RT10 are 1s. If any sample in any bit time (including the start and stop bits) in a character frame fails to agree with the logic level for that bit, the noise flag (NF) will be set when the received character is transferred to the receive data buffer. The falling edge detection logic continuously looks for falling edges, and if an edge is detected, the sample clock is resynchronized to bit times. This improves the reliability of the receiver in the presence of noise or mismatched baud rates. It does not improve worst case analysis because some characters do not have any extra falling edges anywhere in the character frame. In the case of a framing error, provided the received character was not a break character, the sampling logic that searches for a falling edge is filled with three logic 1 samples so that a new start bit can be detected almost immediately. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 193 Serial Communications Interface (S08SCIV3) In the case of a framing error, the receiver is inhibited from receiving any new characters until the framing error flag is cleared. The receive shift register continues to function, but a complete character cannot transfer to the receive data buffer if FE is still set. 11.3.3.2 Receiver Wakeup Operation Receiver wakeup is a hardware mechanism that allows an SCI receiver to ignore the characters in a message that is intended for a different SCI receiver. In such a system, all receivers evaluate the first character(s) of each message, and as soon as they determine the message is intended for a different receiver, they write logic 1 to the receiver wake up (RWU) control bit in SCIxC2. When RWU = 1, it inhibits setting of the status flags associated with the receiver, thus eliminating the software overhead for handling the unimportant message characters. At the end of a message, or at the beginning of the next message, all receivers automatically force RWU to 0 so all receivers wake up in time to look at the first character(s) of the next message. 11.3.3.2.1 Idle-Line Wakeup When WAKE = 0, the receiver is configured for idle-line wakeup. In this mode, RWU is cleared automatically when the receiver detects a full character time of the idle-line level. The M control bit selects 8-bit or 9-bit data mode that determines how many bit times of idle are needed to constitute a full character time (10 or 11 bit times because of the start and stop bits). When the RWU bit is set, the idle character that wakes a receiver does not set the receiver idle bit, IDLE, or the receive data register full flag, RDRF. It therefore will not generate an interrupt when this idle character occurs. The receiver will wake up and wait for the next data transmission which will set RDRF and generate an interrupt if enabled. The idle-line type (ILT) control bit selects one of two ways to detect an idle line. When ILT = 0, the idle bit counter starts after the start bit so the stop bit and any logic 1s at the end of a character count toward the full character time of idle. When ILT = 1, the idle bit counter does not start until after a stop bit time, so the idle detection is not affected by the data in the last character of the previous message. 11.3.3.2.2 Address-Mark Wakeup When WAKE = 1, the receiver is configured for address-mark wakeup. In this mode, RWU is cleared automatically when the receiver detects a logic 1 in the most significant bit of a received character (eighth bit in M = 0 mode and ninth bit in M = 1 mode). Address-mark wakeup allows messages to contain idle characters but requires that the MSB be reserved for use in address frames. The logic 1 MSB of an address frame clears the receivers RWU bit before the stop bit is received and sets the RDRF flag. 11.3.4 Interrupts and Status Flags The SCI system has three separate interrupt vectors to reduce the amount of software needed to isolate the cause of the interrupt. One interrupt vector is associated with the transmitter for TDRE and TC events. Another interrupt vector is associated with the receiver for RDRF and IDLE events, and a third vector is used for OR, NF, FE, and PF error conditions. Each of these eight interrupt sources can be separately MC9S08AW60 Data Sheet, Rev.1.0 194 Freescale Semiconductor Serial Communications Interface (S08SCIV3) masked by local interrupt enable masks. The flags can still be polled by software when the local masks are cleared to disable generation of hardware interrupt requests. The SCI transmitter has two status flags that optionally can generate hardware interrupt requests. Transmit data register empty (TDRE) indicates when there is room in the transmit data buffer to write another transmit character to SCIxD. If the transmit interrupt enable (TIE) bit is set, a hardware interrupt will be requested whenever TDRE = 1. Transmit complete (TC) indicates that the transmitter is finished transmitting all data, preamble, and break characters and is idle with TxD1 high. This flag is often used in systems with modems to determine when it is safe to turn off the modem. If the transmit complete interrupt enable (TCIE) bit is set, a hardware interrupt will be requested whenever TC = 1. Instead of hardware interrupts, software polling may be used to monitor the TDRE and TC status flags if the corresponding TIE or TCIE local interrupt masks are 0s. When a program detects that the receive data register is full (RDRF = 1), it gets the data from the receive data register by reading SCIxD. The RDRF flag is cleared by reading SCIxS1 while RDRF = 1 and then reading SCIxD. When polling is used, this sequence is naturally satisfied in the normal course of the user program. If hardware interrupts are used, SCIxS1 must be read in the interrupt service routine (ISR). Normally, this is done in the ISR anyway to check for receive errors, so the sequence is automatically satisfied. The IDLE status flag includes logic that prevents it from getting set repeatedly when the RxD1 line remains idle for an extended period of time. IDLE is cleared by reading SCIxS1 while IDLE = 1 and then reading SCIxD. After IDLE has been cleared, it cannot become set again until the receiver has received at least one new character and has set RDRF. If the associated error was detected in the received character that caused RDRF to be set, the error flags — noise flag (NF), framing error (FE), and parity error flag (PF) — get set at the same time as RDRF. These flags are not set in overrun cases. If RDRF was already set when a new character is ready to be transferred from the receive shifter to the receive data buffer, the overrun (OR) flag gets set instead and the data and any associated NF, FE, or PF condition is lost. 11.4 Additional SCI Functions The following sections describe additional SCI functions. 11.4.1 8- and 9-Bit Data Modes The SCI system (transmitter and receiver) can be configured to operate in 9-bit data mode by setting the M control bit in SCIxC1. In 9-bit mode, there is a ninth data bit to the left of the MSB of the SCI data register. For the transmit data buffer, this bit is stored in T8 in SCIxC3. For the receiver, the ninth bit is held in R8 in SCIxC3. For coherent writes to the transmit data buffer, write to the T8 bit before writing to SCIxD. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 195 Serial Communications Interface (S08SCIV3) If the bit value to be transmitted as the ninth bit of a new character is the same as for the previous character, it is not necessary to write to T8 again. When data is transferred from the transmit data buffer to the transmit shifter, the value in T8 is copied at the same time data is transferred from SCIxD to the shifter. 9-bit data mode typically is used in conjunction with parity to allow eight bits of data plus the parity in the ninth bit. Or it is used with address-mark wakeup so the ninth data bit can serve as the wakeup bit. In custom protocols, the ninth bit can also serve as a software-controlled marker. 11.4.2 Stop Mode Operation During all stop modes, clocks to the SCI module are halted. In stop1 and stop2 modes, all SCI register data is lost and must be re-initialized upon recovery from these two stop modes. No SCI module registers are affected in stop3 mode. Note, because the clocks are halted, the SCI module will resume operation upon exit from stop (only in stop3 mode). Software should ensure stop mode is not entered while there is a character being transmitted out of or received into the SCI module. 11.4.3 Loop Mode When LOOPS = 1, the RSRC bit in the same register chooses between loop mode (RSRC = 0) or single-wire mode (RSRC = 1). Loop mode is sometimes used to check software, independent of connections in the external system, to help isolate system problems. In this mode, the transmitter output is internally connected to the receiver input and the RxD1 pin is not used by the SCI, so it reverts to a general-purpose port I/O pin. 11.4.4 Single-Wire Operation When LOOPS = 1, the RSRC bit in the same register chooses between loop mode (RSRC = 0) or single-wire mode (RSRC = 1). Single-wire mode is used to implement a half-duplex serial connection. The receiver is internally connected to the transmitter output and to the TxD1 pin. The RxD1 pin is not used and reverts to a general-purpose port I/O pin. In single-wire mode, the TXDIR bit in SCIxC3 controls the direction of serial data on the TxD1 pin. When TXDIR = 0, the TxD1 pin is an input to the SCI receiver and the transmitter is temporarily disconnected from the TxD1 pin so an external device can send serial data to the receiver. When TXDIR = 1, the TxD1 pin is an output driven by the transmitter. In single-wire mode, the internal loop back connection from the transmitter to the receiver causes the receiver to receive characters that are sent out by the transmitter. MC9S08AW60 Data Sheet, Rev.1.0 196 Freescale Semiconductor Chapter 12 Serial Peripheral Interface (S08SPIV3) The MC9S08AW60/48/32/16 has one serial peripheral interface (SPI) module. The four pins associated with SPI functionality are shared with port E pins 4–7. See Appendix A, “Electrical Characteristics and Timing Specifications,” for SPI electrical parametric information. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 197 HCS08 CORE BDC DEBUG MODULE (DBG) RTI COP IRQ LVD SERIAL COMMUNICATIONS INTERFACE MODULE (SCI2) IIC MODULE (IIC1) 10-BIT ANALOG-TO-DIGITAL CONVERTER (ADC1) TxD2 SDA1 SCL1 INTERNAL CLOCK GENERATOR (ICG) 6-CHANNEL TIMER/PWM MODULE (TPM1) LOW-POWER OSCILLATOR SERIAL COMMUNICATIONS INTERFACE MODULE (SCI1) VOLTAGE REGULATOR 2-CHANNEL TIMER/PWM MODULE (TPM2) SPSCK1 MOSI1 PTE7/SPSCK1 MISO1 SS1 TPM1CLK TPM1CH5– TPM1CH0 RxD1 TxD1 PORT E USER RAM AW60/48/32 = 2048 BYTES AW16 = 1024 BYTES PTD7/AD1P15/KBI1P7 PTD6/AD1P14/TPM1CLK PTD5/AD1P13 PTD4/AD1P12/TPM2CLK PTD3/AD1P11/KBI1P6 PTD2/AD1P10/KBI1P5 PTD1/AD1P9 PTD0/AD1P8 8 8 AD1P15–AD1P8 USER FLASH (AW60 = 63,280 BYTES) (AW48 = 49,152 BYTES) (AW32 = 32,768 BYTES) (AW16 = 16,384 BYTES) SERIAL PERIPHERAL INTERFACE MODULE (SPI1) PTC6 PTC5/RxD2 PTC4 PTC3/TxD2 PTC2/MCLK PTC1/SDA1 PTC0/SCL1 RxD2 AD1P7–AD1P0 VSSAD VREFL VREFH 6 TPM2CLK PORT F VSS PTB7/AD1P7– PTB0/AD1P0 PORT C RESETS AND INTERRUPTS MODES OF OPERATION POWER MANAGEMENT VDDAD VDD 8 PORT D IRQ PTA7– PTA0 HCS08 SYSTEM CONTROL TPM2CH1–TPM2CH0 2 KBI1P7–KBI1P5 3 8-BIT KEYBOARD INTERRUPT MODULE (KBI1) KBI1P4–KBI1P0 EXTAL XTAL 5 NOTES: 1. Port pins are software configurable with pullup device if input port. 2. Pin contains software configurable pullup/pulldown device if IRQ is enabled (IRQPE = 1). Pulldown is enabled if rising edge detect is selected (IRQEDG = 1) 3. IRQ does not have a clamp diode to VDD. IRQ should not be driven above VDD. 4. Pin contains integrated pullup device. 5. Pins PTD7, PTD3, PTD2, and PTG4 contain both pullup and pulldown devices. Pulldown enabled when KBI is enabled (KBIPEn = 1) and rising edge is selected (KBEDGn = 1). PORT G RESET 8 CPU PORT B BKGD/MS PORT A SPIChapter 12 Serial Peripheral Interface (S08SPIV3) PTE6/MOSI1 PTE5/MISO1 PTE4/SS1 PTE3/TPM1CH1 PTE2/TPM1CH0 PTE1/RxD1 PTE0/TxD1 PTF7 PTF6 PTF5/TPM2CH1 PTF4/TPM2CH0 PTF3/TPM1CH5 PTF2/TPM1CH4 PTF1/TPM1CH3 PTF0/TPM1CH2 PTG6/EXTAL PTG5/XTAL PTG4/KBI1P4 PTG3/KBI1P3 PTG2/KBI1P2 PTG1/KBI1P1 PTG0/KBI1P0 Figure 12-1. Block Diagram Highlighting the SPI Module MC9S08AW60 Data Sheet, Rev.1.0 198 Freescale Semiconductor 12.1 Introduction The serial peripheral interface (SPI) module provides for full-duplex, synchronous, serial communication between the MCU and peripheral devices. These peripheral devices can include other microcontrollers, analog-to-digital converters, shift registers, sensors, memories, etc. The SPI runs at a baud rate up to the bus clock divided by two. Software can poll the status flags, or SPI operation can be interrupt driven. Module Initialization (Slave): Write: SPI1C1 to configure interrupts, set primary SPI options, slave mode select, and system enable. Write: SPI1C2 to configure optional SPI features Module Initialization (Master): Write: SPI1C1 to configure interrupts, set primary SPI options, master mode select, and system enable. Write: SPI1C2 to configure optional SPI features Write: SPI1BR to set baud rate Module Use: After SPI master initiates transfer by checking that SPTEF = 1 and then writing data to SPID: Wait for SPTEF, then write to SPID Wait for SPRF, then read from SPID Mode fault detection can be enabled for master mode in cases where more than one SPI device might become a master at the same time. SPI1C1 SPIE SPE SPTIE MSTR CPOL CPHA SSOE LSBFE Module/interrupt enables and configuration SPI1C2 MODFEN BIDIROE SPISWAI SPC0 SPR2 SPR1 SPR0 Bit 2 Bit 1 Bit 0 Additional configuration options. SPI1BR SPPR2 SPPR1 SPPR0 Baud rate = (BUSCLK/SPPR[2:0])/SPR2[2:0] SPI1D Bit 7 SPI1S SPRF Bit 6 Bit 5 Bit 4 SPTEF MODF Bit 3 Figure 12-2. SPI Module Quick Start MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 199 Serial Peripheral Interface (S08SPIV3) 12.1.1 Features Features of the SPI module include: • Master or slave mode operation • Full-duplex or single-wire bidirectional option • Programmable transmit bit rate • Double-buffered transmit and receive • Serial clock phase and polarity options • Slave select output • Selectable MSB-first or LSB-first shifting 12.1.2 Block Diagrams This section includes block diagrams showing SPI system connections, the internal organization of the SPI module, and the SPI clock dividers that control the master mode bit rate. 12.1.2.1 SPI System Block Diagram Figure 12-3 shows the SPI modules of two MCUs connected in a master-slave arrangement. The master device initiates all SPI data transfers. During a transfer, the master shifts data out (on the MOSI pin) to the slave while simultaneously shifting data in (on the MISO pin) from the slave. The transfer effectively exchanges the data that was in the SPI shift registers of the two SPI systems. The SPSCK signal is a clock output from the master and an input to the slave. The slave device must be selected by a low level on the slave select input (SS pin). In this system, the master device has configured its SS pin as an optional slave select output. SLAVE MASTER MOSI MOSI SPI SHIFTER 7 6 5 4 3 2 SPI SHIFTER 1 0 MISO SPSCK CLOCK GENERATOR SS MISO 7 6 5 4 3 2 1 0 SPSCK SS Figure 12-3. SPI System Connections MC9S08AW60 Data Sheet, Rev.1.0 200 Freescale Semiconductor Serial Peripheral Interface (S08SPIV3) The most common uses of the SPI system include connecting simple shift registers for adding input or output ports or connecting small peripheral devices such as serial A/D or D/A converters. Although Figure 12-3 shows a system where data is exchanged between two MCUs, many practical systems involve simpler connections where data is unidirectionally transferred from the master MCU to a slave or from a slave to the master MCU. 12.1.2.2 SPI Module Block Diagram Figure 12-4 is a block diagram of the SPI module. The central element of the SPI is the SPI shift register. Data is written to the double-buffered transmitter (write to SPI1D) and gets transferred to the SPI shift register at the start of a data transfer. After shifting in a byte of data, the data is transferred into the double-buffered receiver where it can be read (read from SPI1D). Pin multiplexing logic controls connections between MCU pins and the SPI module. When the SPI is configured as a master, the clock output is routed to the SPSCK pin, the shifter output is routed to MOSI, and the shifter input is routed from the MISO pin. When the SPI is configured as a slave, the SPSCK pin is routed to the clock input of the SPI, the shifter output is routed to MISO, and the shifter input is routed from the MOSI pin. In the external SPI system, simply connect all SPSCK pins to each other, all MISO pins together, and all MOSI pins together. Peripheral devices often use slightly different names for these pins. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 201 Serial Peripheral Interface (S08SPIV3) PIN CONTROL M SPE MOSI (MOMI) S Tx BUFFER (WRITE SPI1D) ENABLE SPI SYSTEM M SHIFT OUT SPI SHIFT REGISTER SHIFT IN MISO (SISO) S SPC0 Rx BUFFER (READ SPI1D) BIDIROE LSBFE SHIFT DIRECTION SHIFT CLOCK Rx BUFFER FULL Tx BUFFER EMPTY MASTER CLOCK BUS RATE CLOCK SPIBR CLOCK GENERATOR MSTR CLOCK LOGIC SLAVE CLOCK MASTER/SLAVE M SPSCK S MASTER/ SLAVE MODE SELECT MODFEN SSOE MODE FAULT DETECTION SS SPRF SPTEF SPTIE MODF SPIE SPI INTERRUPT REQUEST Figure 12-4. SPI Module Block Diagram 12.1.3 SPI Baud Rate Generation As shown in Figure 12-5, the clock source for the SPI baud rate generator is the bus clock. The three prescale bits (SPPR2:SPPR1:SPPR0) choose a prescale divisor of 1, 2, 3, 4, 5, 6, 7, or 8. The three rate select bits (SPR2:SPR1:SPR0) divide the output of the prescaler stage by 2, 4, 8, 16, 32, 64, 128, or 256 to get the internal SPI master mode bit-rate clock. MC9S08AW60 Data Sheet, Rev.1.0 202 Freescale Semiconductor Serial Peripheral Interface (S08SPIV3) BUS CLOCK PRESCALER CLOCK RATE DIVIDER DIVIDE BY 1, 2, 3, 4, 5, 6, 7, or 8 DIVIDE BY 2, 4, 8, 16, 32, 64, 128, or 256 SPPR2:SPPR1:SPPR0 SPR2:SPR1:SPR0 MASTER SPI BIT RATE Figure 12-5. SPI Baud Rate Generation 12.2 External Signal Description The SPI optionally shares four port pins. The function of these pins depends on the settings of SPI control bits. When the SPI is disabled (SPE = 0), these four pins revert to being general-purpose port I/O pins that are not controlled by the SPI. 12.2.1 SPSCK — SPI Serial Clock When the SPI is enabled as a slave, this pin is the serial clock input. When the SPI is enabled as a master, this pin is the serial clock output. 12.2.2 MOSI — Master Data Out, Slave Data In When the SPI is enabled as a master and SPI pin control zero (SPC0) is 0 (not bidirectional mode), this pin is the serial data output. When the SPI is enabled as a slave and SPC0 = 0, this pin is the serial data input. If SPC0 = 1 to select single-wire bidirectional mode, and master mode is selected, this pin becomes the bidirectional data I/O pin (MOMI). Also, the bidirectional mode output enable bit determines whether the pin acts as an input (BIDIROE = 0) or an output (BIDIROE = 1). If SPC0 = 1 and slave mode is selected, this pin is not used by the SPI and reverts to being a general-purpose port I/O pin. 12.2.3 MISO — Master Data In, Slave Data Out When the SPI is enabled as a master and SPI pin control zero (SPC0) is 0 (not bidirectional mode), this pin is the serial data input. When the SPI is enabled as a slave and SPC0 = 0, this pin is the serial data output. If SPC0 = 1 to select single-wire bidirectional mode, and slave mode is selected, this pin becomes the bidirectional data I/O pin (SISO) and the bidirectional mode output enable bit determines whether the pin acts as an input (BIDIROE = 0) or an output (BIDIROE = 1). If SPC0 = 1 and master mode is selected, this pin is not used by the SPI and reverts to being a general-purpose port I/O pin. 12.2.4 SS — Slave Select When the SPI is enabled as a slave, this pin is the low-true slave select input. When the SPI is enabled as a master and mode fault enable is off (MODFEN = 0), this pin is not used by the SPI and reverts to being a general-purpose port I/O pin. When the SPI is enabled as a master and MODFEN = 1, the slave select output enable bit determines whether this pin acts as the mode fault input (SSOE = 0) or as the slave select output (SSOE = 1). MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 203 Serial Peripheral Interface (S08SPIV3) 12.3 Register Definition The SPI has five 8-bit registers to select SPI options, control baud rate, report SPI status, and for transmit/receive data. Refer to the direct-page register summary in the Memory chapter of this data sheet for the absolute address assignments for all SPI registers. This section refers to registers and control bits only by their names, and a Freescale-provided equate or header file is used to translate these names into the appropriate absolute addresses. 12.3.1 SPI Control Register 1 (SPI1C1) This read/write register includes the SPI enable control, interrupt enables, and configuration options. 7 6 5 4 3 2 1 0 SPIE SPE SPTIE MSTR CPOL CPHA SSOE LSBFE 0 0 0 0 0 1 0 0 R W Reset Figure 12-6. SPI Control Register 1 (SPI1C1) Table 12-1. SPI1C1 Field Descriptions Field Description 7 SPIE SPI Interrupt Enable (for SPRF and MODF) — This is the interrupt enable for SPI receive buffer full (SPRF) and mode fault (MODF) events. 0 Interrupts from SPRF and MODF inhibited (use polling) 1 When SPRF or MODF is 1, request a hardware interrupt 6 SPE SPI System Enable — Disabling the SPI halts any transfer that is in progress, clears data buffers, and initializes internal state machines. SPRF is cleared and SPTEF is set to indicate the SPI transmit data buffer is empty. 0 SPI system inactive 1 SPI system enabled 5 SPTIE SPI Transmit Interrupt Enable — This is the interrupt enable bit for SPI transmit buffer empty (SPTEF). 0 Interrupts from SPTEF inhibited (use polling) 1 When SPTEF is 1, hardware interrupt requested 4 MSTR Master/Slave Mode Select 0 SPI module configured as a slave SPI device 1 SPI module configured as a master SPI device 3 CPOL Clock Polarity — This bit effectively places an inverter in series with the clock signal from a master SPI or to a slave SPI device. Refer to Section 12.4.1, “SPI Clock Formats” for more details. 0 Active-high SPI clock (idles low) 1 Active-low SPI clock (idles high) 2 CPHA Clock Phase — This bit selects one of two clock formats for different kinds of synchronous serial peripheral devices. Refer to Section 12.4.1, “SPI Clock Formats” for more details. 0 First edge on SPSCK occurs at the middle of the first cycle of an 8-cycle data transfer 1 First edge on SPSCK occurs at the start of the first cycle of an 8-cycle data transfer MC9S08AW60 Data Sheet, Rev.1.0 204 Freescale Semiconductor Serial Peripheral Interface (S08SPIV3) Table 12-1. SPI1C1 Field Descriptions (continued) Field Description 1 SSOE Slave Select Output Enable — This bit is used in combination with the mode fault enable (MODFEN) bit in SPI1C2 and the master/slave (MSTR) control bit to determine the function of the SS pin as shown in Table 12-2. 0 LSBFE LSB First (Shifter Direction) 0 SPI serial data transfers start with most significant bit 1 SPI serial data transfers start with least significant bit Table 12-2. SS Pin Function 12.3.2 MODFEN SSOE Master Mode Slave Mode 0 0 General-purpose I/O (not SPI) Slave select input 0 1 General-purpose I/O (not SPI) Slave select input 1 0 SS input for mode fault Slave select input 1 1 Automatic SS output Slave select input SPI Control Register 2 (SPI1C2) This read/write register is used to control optional features of the SPI system. Bits 7, 6, 5, and 2 are not implemented and always read 0. R 7 6 5 0 0 0 4 3 MODFEN BIDIROE 0 0 2 1 0 SPISWAI SPC0 0 0 0 W Reset 0 0 0 0 = Unimplemented or Reserved Figure 12-7. SPI Control Register 2 (SPI1C2) Table 12-3. SPI1C2 Register Field Descriptions Field Description 4 MODFEN Master Mode-Fault Function Enable — When the SPI is configured for slave mode, this bit has no meaning or effect. (The SS pin is the slave select input.) In master mode, this bit determines how the SS pin is used (refer to Table 12-2 for more details). 0 Mode fault function disabled, master SS pin reverts to general-purpose I/O not controlled by SPI 1 Mode fault function enabled, master SS pin acts as the mode fault input or the slave select output 3 BIDIROE Bidirectional Mode Output Enable — When bidirectional mode is enabled by SPI pin control 0 (SPC0) = 1, BIDIROE determines whether the SPI data output driver is enabled to the single bidirectional SPI I/O pin. Depending on whether the SPI is configured as a master or a slave, it uses either the MOSI (MOMI) or MISO (SISO) pin, respectively, as the single SPI data I/O pin. When SPC0 = 0, BIDIROE has no meaning or effect. 0 Output driver disabled so SPI data I/O pin acts as an input 1 SPI I/O pin enabled as an output MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 205 Serial Peripheral Interface (S08SPIV3) Table 12-3. SPI1C2 Register Field Descriptions (continued) Field 1 SPISWAI 0 SPC0 12.3.3 Description SPI Stop in Wait Mode 0 SPI clocks continue to operate in wait mode 1 SPI clocks stop when the MCU enters wait mode SPI Pin Control 0 — The SPC0 bit chooses single-wire bidirectional mode. If MSTR = 0 (slave mode), the SPI uses the MISO (SISO) pin for bidirectional SPI data transfers. If MSTR = 1 (master mode), the SPI uses the MOSI (MOMI) pin for bidirectional SPI data transfers. When SPC0 = 1, BIDIROE is used to enable or disable the output driver for the single bidirectional SPI I/O pin. 0 SPI uses separate pins for data input and data output 1 SPI configured for single-wire bidirectional operation SPI Baud Rate Register (SPI1BR) This register is used to set the prescaler and bit rate divisor for an SPI master. This register may be read or written at any time. 7 R 6 5 4 3 SPPR2 SPPR1 SPPR0 0 0 0 0 2 1 0 SPR2 SPR1 SPR0 0 0 0 0 W Reset 0 0 = Unimplemented or Reserved Figure 12-8. SPI Baud Rate Register (SPI1BR) Table 12-4. SPI1BR Register Field Descriptions Field Description 6:4 SPPR[2:0] SPI Baud Rate Prescale Divisor — This 3-bit field selects one of eight divisors for the SPI baud rate prescaler as shown in Table 12-5. The input to this prescaler is the bus rate clock (BUSCLK). The output of this prescaler drives the input of the SPI baud rate divider (see Figure 12-5). 2:0 SPR[2:0] SPI Baud Rate Divisor — This 3-bit field selects one of eight divisors for the SPI baud rate divider as shown in Table 12-6. The input to this divider comes from the SPI baud rate prescaler (see Figure 12-5). The output of this divider is the SPI bit rate clock for master mode. Table 12-5. SPI Baud Rate Prescaler Divisor SPPR2:SPPR1:SPPR0 Prescaler Divisor 0:0:0 1 0:0:1 2 0:1:0 3 0:1:1 4 1:0:0 5 1:0:1 6 1:1:0 7 1:1:1 8 MC9S08AW60 Data Sheet, Rev.1.0 206 Freescale Semiconductor Serial Peripheral Interface (S08SPIV3) Table 12-6. SPI Baud Rate Divisor 12.3.4 SPR2:SPR1:SPR0 Rate Divisor 0:0:0 2 0:0:1 4 0:1:0 8 0:1:1 16 1:0:0 32 1:0:1 64 1:1:0 128 1:1:1 256 SPI Status Register (SPI1S) This register has three read-only status bits. Bits 6, 3, 2, 1, and 0 are not implemented and always read 0. Writes have no meaning or effect. R 7 6 5 4 3 2 1 0 SPRF 0 SPTEF MODF 0 0 0 0 0 0 1 0 0 0 0 0 W Reset = Unimplemented or Reserved Figure 12-9. SPI Status Register (SPI1S) Table 12-7. SPI1S Register Field Descriptions Field Description 7 SPRF SPI Read Buffer Full Flag — SPRF is set at the completion of an SPI transfer to indicate that received data may be read from the SPI data register (SPI1D). SPRF is cleared by reading SPRF while it is set, then reading the SPI data register. 0 No data available in the receive data buffer 1 Data available in the receive data buffer MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 207 Serial Peripheral Interface (S08SPIV3) Table 12-7. SPI1S Register Field Descriptions Field Description 5 SPTEF SPI Transmit Buffer Empty Flag — This bit is set when there is room in the transmit data buffer. It is cleared by reading SPI1S with SPTEF set, followed by writing a data value to the transmit buffer at SPI1D. SPI1S must be read with SPTEF = 1 before writing data to SPI1D or the SPI1D write will be ignored. SPTEF generates an SPTEF CPU interrupt request if the SPTIE bit in the SPI1C1 is also set. SPTEF is automatically set when a data byte transfers from the transmit buffer into the transmit shift register. For an idle SPI (no data in the transmit buffer or the shift register and no transfer in progress), data written to SPI1D is transferred to the shifter almost immediately so SPTEF is set within two bus cycles allowing a second 8-bit data value to be queued into the transmit buffer. After completion of the transfer of the value in the shift register, the queued value from the transmit buffer will automatically move to the shifter and SPTEF will be set to indicate there is room for new data in the transmit buffer. If no new data is waiting in the transmit buffer, SPTEF simply remains set and no data moves from the buffer to the shifter. 0 SPI transmit buffer not empty 1 SPI transmit buffer empty 4 MODF Master Mode Fault Flag — MODF is set if the SPI is configured as a master and the slave select input goes low, indicating some other SPI device is also configured as a master. The SS pin acts as a mode fault error input only when MSTR = 1, MODFEN = 1, and SSOE = 0; otherwise, MODF will never be set. MODF is cleared by reading MODF while it is 1, then writing to SPI control register 1 (SPI1C1). 0 No mode fault error 1 Mode fault error detected 12.3.5 SPI Data Register (SPI1D) 7 6 5 4 3 2 1 0 Bit 7 6 5 4 3 2 1 Bit 0 0 0 0 0 0 0 0 0 R W Reset Figure 12-10. SPI Data Register (SPI1D) Reads of this register return the data read from the receive data buffer. Writes to this register write data to the transmit data buffer. When the SPI is configured as a master, writing data to the transmit data buffer initiates an SPI transfer. Data should not be written to the transmit data buffer unless the SPI transmit buffer empty flag (SPTEF) is set, indicating there is room in the transmit buffer to queue a new transmit byte. Data may be read from SPI1D any time after SPRF is set and before another transfer is finished. Failure to read the data out of the receive data buffer before a new transfer ends causes a receive overrun condition and the data from the new transfer is lost. 12.4 Functional Description An SPI transfer is initiated by checking for the SPI transmit buffer empty flag (SPTEF = 1) and then writing a byte of data to the SPI data register (SPI1D) in the master SPI device. When the SPI shift register is available, this byte of data is moved from the transmit data buffer to the shifter, SPTEF is set to indicate there is room in the buffer to queue another transmit character if desired, and the SPI serial transfer starts. MC9S08AW60 Data Sheet, Rev.1.0 208 Freescale Semiconductor Serial Peripheral Interface (S08SPIV3) During the SPI transfer, data is sampled (read) on the MISO pin at one SPSCK edge and shifted, changing the bit value on the MOSI pin, one-half SPSCK cycle later. After eight SPSCK cycles, the data that was in the shift register of the master has been shifted out the MOSI pin to the slave while eight bits of data were shifted in the MISO pin into the master’s shift register. At the end of this transfer, the received data byte is moved from the shifter into the receive data buffer and SPRF is set to indicate the data can be read by reading SPI1D. If another byte of data is waiting in the transmit buffer at the end of a transfer, it is moved into the shifter, SPTEF is set, and a new transfer is started. Normally, SPI data is transferred most significant bit (MSB) first. If the least significant bit first enable (LSBFE) bit is set, SPI data is shifted LSB first. When the SPI is configured as a slave, its SS pin must be driven low before a transfer starts and SS must stay low throughout the transfer. If a clock format where CPHA = 0 is selected, SS must be driven to a logic 1 between successive transfers. If CPHA = 1, SS may remain low between successive transfers. See Section 12.4.1, “SPI Clock Formats” for more details. Because the transmitter and receiver are double buffered, a second byte, in addition to the byte currently being shifted out, can be queued into the transmit data buffer, and a previously received character can be in the receive data buffer while a new character is being shifted in. The SPTEF flag indicates when the transmit buffer has room for a new character. The SPRF flag indicates when a received character is available in the receive data buffer. The received character must be read out of the receive buffer (read SPI1D) before the next transfer is finished or a receive overrun error results. In the case of a receive overrun, the new data is lost because the receive buffer still held the previous character and was not ready to accept the new data. There is no indication for such an overrun condition so the application system designer must ensure that previous data has been read from the receive buffer before a new transfer is initiated. 12.4.1 SPI Clock Formats To accommodate a wide variety of synchronous serial peripherals from different manufacturers, the SPI system has a clock polarity (CPOL) bit and a clock phase (CPHA) control bit to select one of four clock formats for data transfers. CPOL selectively inserts an inverter in series with the clock. CPHA chooses between two different clock phase relationships between the clock and data. Figure 12-11 shows the clock formats when CPHA = 1. At the top of the figure, the eight bit times are shown for reference with bit 1 starting at the first SPSCK edge and bit 8 ending one-half SPSCK cycle after the sixteenth SPSCK edge. The MSB first and LSB first lines show the order of SPI data bits depending on the setting in LSBFE. Both variations of SPSCK polarity are shown, but only one of these waveforms applies for a specific transfer, depending on the value in CPOL. The SAMPLE IN waveform applies to the MOSI input of a slave or the MISO input of a master. The MOSI waveform applies to the MOSI output pin from a master and the MISO waveform applies to the MISO output from a slave. The SS OUT waveform applies to the slave select output from a master (provided MODFEN and SSOE = 1). The master SS output goes to active low one-half SPSCK cycle before the start of the transfer and goes back high at the end of the eighth bit time of the transfer. The SS IN waveform applies to the slave select input of a slave. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 209 Serial Peripheral Interface (S08SPIV3) BIT TIME # (REFERENCE) 1 2 ... 6 7 8 BIT 7 BIT 0 BIT 6 BIT 1 ... ... BIT 2 BIT 5 BIT 1 BIT 6 BIT 0 BIT 7 SPSCK (CPOL = 0) SPSCK (CPOL = 1) SAMPLE IN (MISO OR MOSI) MOSI (MASTER OUT) MSB FIRST LSB FIRST MISO (SLAVE OUT) SS OUT (MASTER) SS IN (SLAVE) Figure 12-11. SPI Clock Formats (CPHA = 1) When CPHA = 1, the slave begins to drive its MISO output when SS goes to active low, but the data is not defined until the first SPSCK edge. The first SPSCK edge shifts the first bit of data from the shifter onto the MOSI output of the master and the MISO output of the slave. The next SPSCK edge causes both the master and the slave to sample the data bit values on their MISO and MOSI inputs, respectively. At the third SPSCK edge, the SPI shifter shifts one bit position which shifts in the bit value that was just sampled, and shifts the second data bit value out the other end of the shifter to the MOSI and MISO outputs of the master and slave, respectively. When CHPA = 1, the slave’s SS input is not required to go to its inactive high level between transfers. Figure 12-12 shows the clock formats when CPHA = 0. At the top of the figure, the eight bit times are shown for reference with bit 1 starting as the slave is selected (SS IN goes low), and bit 8 ends at the last SPSCK edge. The MSB first and LSB first lines show the order of SPI data bits depending on the setting in LSBFE. Both variations of SPSCK polarity are shown, but only one of these waveforms applies for a specific transfer, depending on the value in CPOL. The SAMPLE IN waveform applies to the MOSI input of a slave or the MISO input of a master. The MOSI waveform applies to the MOSI output pin from a master and the MISO waveform applies to the MISO output from a slave. The SS OUT waveform applies to the slave select output from a master (provided MODFEN and SSOE = 1). The master SS output goes to active low at the start of the first bit time of the transfer and goes back high one-half SPSCK cycle after MC9S08AW60 Data Sheet, Rev.1.0 210 Freescale Semiconductor Serial Peripheral Interface (S08SPIV3) the end of the eighth bit time of the transfer. The SS IN waveform applies to the slave select input of a slave. BIT TIME # (REFERENCE) 1 2 BIT 7 BIT 0 BIT 6 BIT 1 ... 6 7 8 BIT 2 BIT 5 BIT 1 BIT 6 BIT 0 BIT 7 SPSCK (CPOL = 0) SPSCK (CPOL = 1) SAMPLE IN (MISO OR MOSI) MOSI (MASTER OUT) MSB FIRST LSB FIRST ... ... MISO (SLAVE OUT) SS OUT (MASTER) SS IN (SLAVE) Figure 12-12. SPI Clock Formats (CPHA = 0) When CPHA = 0, the slave begins to drive its MISO output with the first data bit value (MSB or LSB depending on LSBFE) when SS goes to active low. The first SPSCK edge causes both the master and the slave to sample the data bit values on their MISO and MOSI inputs, respectively. At the second SPSCK edge, the SPI shifter shifts one bit position which shifts in the bit value that was just sampled and shifts the second data bit value out the other end of the shifter to the MOSI and MISO outputs of the master and slave, respectively. When CPHA = 0, the slave’s SS input must go to its inactive high level between transfers. 12.4.2 SPI Interrupts There are three flag bits, two interrupt mask bits, and one interrupt vector associated with the SPI system. The SPI interrupt enable mask (SPIE) enables interrupts from the SPI receiver full flag (SPRF) and mode fault flag (MODF). The SPI transmit interrupt enable mask (SPTIE) enables interrupts from the SPI transmit buffer empty flag (SPTEF). When one of the flag bits is set, and the associated interrupt mask bit is set, a hardware interrupt request is sent to the CPU. If the interrupt mask bits are cleared, software can poll the associated flag bits instead of using interrupts. The SPI interrupt service routine (ISR) should MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 211 Serial Peripheral Interface (S08SPIV3) check the flag bits to determine what event caused the interrupt. The service routine should also clear the flag bit(s) before returning from the ISR (usually near the beginning of the ISR). 12.4.3 Mode Fault Detection A mode fault occurs and the mode fault flag (MODF) becomes set when a master SPI device detects an error on the SS pin (provided the SS pin is configured as the mode fault input signal). The SS pin is configured to be the mode fault input signal when MSTR = 1, mode fault enable is set (MODFEN = 1), and slave select output enable is clear (SSOE = 0). The mode fault detection feature can be used in a system where more than one SPI device might become a master at the same time. The error is detected when a master’s SS pin is low, indicating that some other SPI device is trying to address this master as if it were a slave. This could indicate a harmful output driver conflict, so the mode fault logic is designed to disable all SPI output drivers when such an error is detected. When a mode fault is detected, MODF is set and MSTR is cleared to change the SPI configuration back to slave mode. The output drivers on the SPSCK, MOSI, and MISO (if not bidirectional mode) are disabled. MODF is cleared by reading it while it is set, then writing to the SPI control register 1 (SPI1C1). User software should verify the error condition has been corrected before changing the SPI back to master mode. 12.5 Initialization/Application Information 12.5.1 12.5.1.1 SPI Module Initialization Example Initialization Sequence Before the SPI module can be used for communication, an initialization procedure must be carried out, as follows: 1. Update control register 1 (SPI1C1) to enable the SPI and to control interrupt enables. This register also sets the SPI as master or slave, determines clock phase and polarity, and configures the main SPI options. 2. Update control register 2 (SPI1C2) to enable additional SPI functions such as the master mode-fault function and bidirectional mode output. Other optional SPI functions are configured here as well. 3. Update the baud rate register (SPI1BR) to set the prescaler and bit rate divisor for an SPI master. 12.5.1.2 Pseudo—Code Example In this example, the SPI module will be set up for master mode with only transmit interrupts enabled to run at a maximum baud rate of bus clock divided by 2. Clock phase and polarity will be set for an active-high SPI clock where the first edge on SPSCK occurs at the start of the first cycle of a data transfer. MC9S08AW60 Data Sheet, Rev.1.0 212 Freescale Semiconductor Serial Peripheral Interface (S08SPIV3) SPI1C1 = 0x74(%01110100) Bit 7 SPIE = 0 Disables receive and mode fault interrupts Bit 6 SPE = 1 Enables the SPI system Bit 5 SPTIE = 1 Enables SPI transmit interrupts Bit 4 MSTR = 1 Sets the SPI module as a master SPI device Bit 3 CPOL = 0 Configures SPI clock as active-high Bit 2 CPHA = 1 First edge on SPSCK at start of first data transfer cycle Bit 1 SSOE = 0 Determines SS pin function when mode fault enabled Bit 0 LSBFE = 0 SPI serial data transfers start with most significant bit SPI1C2 = 0x00(%00000000) Bit 7:5 = 000 Unimplemented Bit 4 MODFEN = 0 Disables mode fault function Bit 3 BIDIROE = 0 SPI data I/O pin acts as input = 0 Unimplemented Bit 2 Bit 1 SPISWAI = 0 SPI clocks operate in wait mode Bit 0 SPC0 = 0 SPI uses separate pins for data input and output SPI1BR = 0x00(%00000000) Bit 7 = 0 Unimplemented Bit 6:4 = 000 Sets prescale divisor to 1 Bit 3 = 0 Unimplemented Bit 2:0 = 000 Sets baud rate divisor to 2 = 0 Flag is set when receive data buffer is full SPI1S = 0x00(%00000000) Bit 7 SPRF Bit 6 = 0 Unimplemented Bit 5 SPTEF = 0 Flag is set when transmit data buffer is empty Bit 4 MODF = 0 Mode fault flag for master mode = 0 Unimplemented Bit 3:0 SPI1D = 0xxx Holds data to be transmitted by transmit buffer and data received by receive buffer. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 213 Serial Peripheral Interface (S08SPIV3) RESET INITIALIZE SPI SPI1C1 = 0x74 SPI1C2 = 0x00 SPI1BR = 0x00 SPTEF = 1 ? NO YES READ SPI1S WITH SPTEF SET TO CLEAR FLAG, THEN WRITE DATA TO SPI1D CONTINUE Figure 12-13. Initialization Flowchart Example for SPI Master Device MC9S08AW60 Data Sheet, Rev.1.0 214 Freescale Semiconductor Chapter 13 Inter-Integrated Circuit (S08IICV1) 13.1 Introduction The MC9S08AW60/48/32/16 series of microcontrollers has an inter-integrated circuit (IIC) module for communication with other integrated circuits. The two pins associated with this module, SCL and SDA, are shared with port C pins 0 and 1, respectively. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 215 HCS08 CORE BDC DEBUG MODULE (DBG) RTI COP IRQ LVD SERIAL COMMUNICATIONS INTERFACE MODULE (SCI2) IIC MODULE (IIC1) 10-BIT ANALOG-TO-DIGITAL CONVERTER (ADC1) TxD2 SDA1 SCL1 INTERNAL CLOCK GENERATOR (ICG) 6-CHANNEL TIMER/PWM MODULE (TPM1) LOW-POWER OSCILLATOR SERIAL COMMUNICATIONS INTERFACE MODULE (SCI1) VOLTAGE REGULATOR 2-CHANNEL TIMER/PWM MODULE (TPM2) SPSCK1 MOSI1 PTE7/SPSCK1 MISO1 SS1 TPM1CLK TPM1CH5– TPM1CH0 RxD1 TxD1 PORT E USER RAM AW60/48/32 = 2048 BYTES AW16 = 1024 BYTES PTD7/AD1P15/KBI1P7 PTD6/AD1P14/TPM1CLK PTD5/AD1P13 PTD4/AD1P12/TPM2CLK PTD3/AD1P11/KBI1P6 PTD2/AD1P10/KBI1P5 PTD1/AD1P9 PTD0/AD1P8 8 8 AD1P15–AD1P8 USER FLASH (AW60 = 63,280 BYTES) (AW48 = 49,152 BYTES) (AW32 = 32,768 BYTES) (AW16 = 16,384 BYTES) SERIAL PERIPHERAL INTERFACE MODULE (SPI1) PTC6 PTC5/RxD2 PTC4 PTC3/TxD2 PTC2/MCLK PTC1/SDA1 PTC0/SCL1 RxD2 AD1P7–AD1P0 VSSAD VREFL VREFH 6 TPM2CLK PORT F VSS PTB7/AD1P7– PTB0/AD1P0 PORT C RESETS AND INTERRUPTS MODES OF OPERATION POWER MANAGEMENT VDDAD VDD 8 PORT D IRQ PTA7– PTA0 HCS08 SYSTEM CONTROL TPM2CH1–TPM2CH0 2 KBI1P7–KBI1P5 3 8-BIT KEYBOARD INTERRUPT MODULE (KBI1) KBI1P4–KBI1P0 EXTAL XTAL 5 NOTES: 1. Port pins are software configurable with pullup device if input port. 2. Pin contains software configurable pullup/pulldown device if IRQ is enabled (IRQPE = 1). Pulldown is enabled if rising edge detect is selected (IRQEDG = 1) 3. IRQ does not have a clamp diode to VDD. IRQ should not be driven above VDD. 4. Pin contains integrated pullup device. 5. Pins PTD7, PTD3, PTD2, and PTG4 contain both pullup and pulldown devices. Pulldown enabled when KBI is enabled (KBIPEn = 1) and rising edge is selected (KBEDGn = 1). PORT G RESET 8 CPU PORT B BKGD/MS PORT A IICChapter 13 Inter-Integrated Circuit (S08IICV1) PTE6/MOSI1 PTE5/MISO1 PTE4/SS1 PTE3/TPM1CH1 PTE2/TPM1CH0 PTE1/RxD1 PTE0/TxD1 PTF7 PTF6 PTF5/TPM2CH1 PTF4/TPM2CH0 PTF3/TPM1CH5 PTF2/TPM1CH4 PTF1/TPM1CH3 PTF0/TPM1CH2 PTG6/EXTAL PTG5/XTAL PTG4/KBI1P4 PTG3/KBI1P3 PTG2/KBI1P2 PTG1/KBI1P1 PTG0/KBI1P0 Figure 13-1. Block Diagram Highlighting the IIC Module MC9S08AW60 Data Sheet, Rev.1.0 216 Freescale Semiconductor Inter-Integrated Circuit (S08IICV1) 13.1.1 Features The IIC includes these distinctive features: • Compatible with IIC bus standard • Multi-master operation • Software programmable for one of 64 different serial clock frequencies • Software selectable acknowledge bit • Interrupt driven byte-by-byte data transfer • Arbitration lost interrupt with automatic mode switching from master to slave • Calling address identification interrupt • START and STOP signal generation/detection • Repeated START signal generation • Acknowledge bit generation/detection • Bus busy detection 13.1.2 Modes of Operation The IIC functions the same in normal and monitor modes. A brief description of the IIC in the various MCU modes is given here. • Run mode — This is the basic mode of operation. To conserve power in this mode, disable the module. • Wait mode — The module will continue to operate while the MCU is in wait mode and can provide a wake-up interrupt. • Stop mode — The IIC is inactive in stop3 mode for reduced power consumption. The STOP instruction does not affect IIC register states. Stop1 and stop2 will reset the register contents. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 217 Inter-Integrated Circuit (S08IICV1) 13.1.3 Block Diagram Figure 13-2 is a block diagram of the IIC. ADDRESS DATA BUS INTERRUPT ADDR_DECODE CTRL_REG DATA_MUX FREQ_REG ADDR_REG STATUS_REG DATA_REG INPUT SYNC START STOP ARBITRATION CONTROL CLOCK CONTROL IN/OUT DATA SHIFT REGISTER ADDRESS COMPARE SCL SDA Figure 13-2. IIC Functional Block Diagram 13.2 External Signal Description This section describes each user-accessible pin signal. 13.2.1 SCL — Serial Clock Line The bidirectional SCL is the serial clock line of the IIC system. 13.2.2 SDA — Serial Data Line The bidirectional SDA is the serial data line of the IIC system. 13.3 Register Definition This section consists of the IIC register descriptions in address order. MC9S08AW60 Data Sheet, Rev.1.0 218 Freescale Semiconductor Inter-Integrated Circuit (S08IICV1) Refer to the direct-page register summary in the Memory chapter of this data sheet for the absolute address assignments for all IIC registers. This section refers to registers and control bits only by their names. A Freescale-provided equate or header file is used to translate these names into the appropriate absolute addresses. 13.3.1 IIC Address Register (IIC1A) 7 6 5 4 3 2 1 0 0 R ADDR W Reset 0 0 0 0 0 0 0 0 = Unimplemented or Reserved Figure 13-3. IIC Address Register (IIC1A) Table 13-1. IIC1A Register Field Descriptions Field Description 7:1 ADDR[7:1] IIC Address Register — The ADDR contains the specific slave address to be used by the IIC module. This is the address the module will respond to when addressed as a slave. 13.3.2 IIC Frequency Divider Register (IIC1F) 7 6 5 4 3 2 1 0 0 0 0 R MULT ICR W Reset 0 0 0 0 0 Figure 13-4. IIC Frequency Divider Register (IIC1F) MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 219 Inter-Integrated Circuit (S08IICV1) Table 13-2. IIC1A Register Field Descriptions Field Description 7:6 MULT IIC Multiplier Factor — The MULT bits define the multiplier factor mul. This factor is used along with the SCL divider to generate the IIC baud rate. The multiplier factor mul as defined by the MULT bits is provided below. 00 mul = 01 01 mul = 02 10 mul = 04 11 Reserved 5:0 ICR IIC Clock Rate — The ICR bits are used to prescale the bus clock for bit rate selection. These bits are used to define the SCL divider and the SDA hold value. The SCL divider multiplied by the value provided by the MULT register (multiplier factor mul) is used to generate IIC baud rate. IIC baud rate = bus speed (Hz)/(mul * SCL divider) SDA hold time is the delay from the falling edge of the SCL (IIC clock) to the changing of SDA (IIC data). The ICR is used to determine the SDA hold value. SDA hold time = bus period (s) * SDA hold value Table 13-3 provides the SCL divider and SDA hold values for corresponding values of the ICR. These values can be used to set IIC baud rate and SDA hold time. For example: Bus speed = 8 MHz MULT is set to 01 (mul = 2) Desired IIC baud rate = 100 kbps IIC baud rate = bus speed (Hz)/(mul * SCL divider) 100000 = 8000000/(2*SCL divider) SCL divider = 40 Table 13-3 shows that ICR must be set to 0B to provide an SCL divider of 40 and that this will result in an SDA hold value of 9. SDA hold time = bus period (s) * SDA hold value SDA hold time = 1/8000000 * 9 = 1.125 µs If the generated SDA hold value is not acceptable, the MULT bits can be used to change the ICR. This will result in a different SDA hold value. MC9S08AW60 Data Sheet, Rev.1.0 220 Freescale Semiconductor Inter-Integrated Circuit (S08IICV1) Table 13-3. IIC Divider and Hold Values ICR (hex) SCL Divider SDA Hold Value ICR (hex) SCL Divider SDA Hold Value 00 20 7 20 160 17 01 22 7 21 192 17 02 24 8 22 224 33 03 26 8 23 256 33 04 28 9 24 288 49 05 30 9 25 320 49 06 34 10 26 384 65 07 40 10 27 480 65 08 28 7 28 320 33 09 32 7 29 384 33 0A 36 9 2A 448 65 0B 40 9 2B 512 65 0C 44 11 2C 576 97 0D 48 11 2D 640 97 0E 56 13 2E 768 129 0F 68 13 2F 960 129 10 48 9 30 640 65 11 56 9 31 768 65 12 64 13 32 896 129 13 72 13 33 1024 129 14 80 17 34 1152 193 15 88 17 35 1280 193 16 104 21 36 1536 257 17 128 21 37 1920 257 18 80 9 38 1280 129 19 96 9 39 1536 129 1A 112 17 3A 1792 257 1B 128 17 3B 2048 257 1C 144 25 3C 2304 385 1D 160 25 3D 2560 385 1E 192 33 3E 3072 513 1F 240 33 3F 3840 513 MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 221 Inter-Integrated Circuit (S08IICV1) 13.3.3 IIC Control Register (IIC1C) 7 6 5 4 3 IICEN IICIE MST TX TXAK R W Reset 2 1 0 0 0 0 0 0 RSTA 0 0 0 0 0 0 = Unimplemented or Reserved Figure 13-5. IIC Control Register (IIC1C) Table 13-4. IIC1C Register Field Descriptions Field Description 7 IICEN IIC Enable — The IICEN bit determines whether the IIC module is enabled. 0 IIC is not enabled. 1 IIC is enabled. 6 IICIE IIC Interrupt Enable — The IICIE bit determines whether an IIC interrupt is requested. 0 IIC interrupt request not enabled. 1 IIC interrupt request enabled. 5 MST Master Mode Select — The MST bit is changed from a 0 to a 1 when a START signal is generated on the bus and master mode is selected. When this bit changes from a 1 to a 0 a STOP signal is generated and the mode of operation changes from master to slave. 0 Slave Mode. 1 Master Mode. 4 TX Transmit Mode Select — The TX bit selects the direction of master and slave transfers. In master mode this bit should be set according to the type of transfer required. Therefore, for address cycles, this bit will always be high. When addressed as a slave this bit should be set by software according to the SRW bit in the status register. 0 Receive. 1 Transmit. 3 TXAK Transmit Acknowledge Enable — This bit specifies the value driven onto the SDA during data acknowledge cycles for both master and slave receivers. 0 An acknowledge signal will be sent out to the bus after receiving one data byte. 1 No acknowledge signal response is sent. 2 RSTA Repeat START — Writing a one to this bit will generate a repeated START condition provided it is the current master. This bit will always be read as a low. Attempting a repeat at the wrong time will result in loss of arbitration. MC9S08AW60 Data Sheet, Rev.1.0 222 Freescale Semiconductor Inter-Integrated Circuit (S08IICV1) 13.3.4 IIC Status Register (IIC1S) 7 R 6 TCF 5 4 BUSY IAAS 3 2 0 SRW ARBL 1 0 RXAK IICIF W Reset 1 0 0 0 0 0 0 0 = Unimplemented or Reserved Figure 13-6. IIC Status Register (IIC1S) Table 13-5. IIC1S Register Field Descriptions Field Description 7 TCF Transfer Complete Flag — This bit is set on the completion of a byte transfer. Note that this bit is only valid during or immediately following a transfer to the IIC module or from the IIC module.The TCF bit is cleared by reading the IIC1D register in receive mode or writing to the IIC1D in transmit mode. 0 Transfer in progress. 1 Transfer complete. 6 IAAS Addressed as a Slave — The IAAS bit is set when the calling address matches the programmed slave address. Writing the IIC1C register clears this bit. 0 Not addressed. 1 Addressed as a slave. 5 BUSY Bus Busy — The BUSY bit indicates the status of the bus regardless of slave or master mode. The BUSY bit is set when a START signal is detected and cleared when a STOP signal is detected. 0 Bus is idle. 1 Bus is busy. 4 ARBL Arbitration Lost — This bit is set by hardware when the arbitration procedure is lost. The ARBL bit must be cleared by software, by writing a one to it. 0 Standard bus operation. 1 Loss of arbitration. 2 SRW Slave Read/Write — When addressed as a slave the SRW bit indicates the value of the R/W command bit of the calling address sent to the master. 0 Slave receive, master writing to slave. 1 Slave transmit, master reading from slave. 1 IICIF IIC Interrupt Flag — The IICIF bit is set when an interrupt is pending. This bit must be cleared by software, by writing a one to it in the interrupt routine. One of the following events can set the IICIF bit: • One byte transfer completes • Match of slave address to calling address • Arbitration lost 0 No interrupt pending. 1 Interrupt pending. 0 RXAK Receive Acknowledge — When the RXAK bit is low, it indicates an acknowledge signal has been received after the completion of one byte of data transmission on the bus. If the RXAK bit is high it means that no acknowledge signal is detected. 0 Acknowledge received. 1 No acknowledge received. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 223 Inter-Integrated Circuit (S08IICV1) 13.3.5 IIC Data I/O Register (IIC1D) 7 6 5 4 3 2 1 0 0 0 0 0 R DATA W Reset 0 0 0 0 Figure 13-7. IIC Data I/O Register (IIC1D) Table 13-6. IIC1D Register Field Descriptions Field Description 7:0 DATA Data — In master transmit mode, when data is written to the IIC1D, a data transfer is initiated. The most significant bit is sent first. In master receive mode, reading this register initiates receiving of the next byte of data. NOTE When transitioning out of master receive mode, the IIC mode should be switched before reading the IIC1D register to prevent an inadvertent initiation of a master receive data transfer. In slave mode, the same functions are available after an address match has occurred. Note that the TX bit in IIC1C must correctly reflect the desired direction of transfer in master and slave modes for the transmission to begin. For instance, if the IIC is configured for master transmit but a master receive is desired, then reading the IIC1D will not initiate the receive. Reading the IIC1D will return the last byte received while the IIC is configured in either master receive or slave receive modes. The IIC1D does not reflect every byte that is transmitted on the IIC bus, nor can software verify that a byte has been written to the IIC1D correctly by reading it back. In master transmit mode, the first byte of data written to IIC1D following assertion of MST is used for the address transfer and should comprise of the calling address (in bit 7–bit 1) concatenated with the required R/W bit (in position bit 0). MC9S08AW60 Data Sheet, Rev.1.0 224 Freescale Semiconductor Inter-Integrated Circuit (S08IICV1) 13.4 Functional Description This section provides a complete functional description of the IIC module. 13.4.1 IIC Protocol The IIC bus system uses a serial data line (SDA) and a serial clock line (SCL) for data transfer. All devices connected to it must have open drain or open collector outputs. A logic AND function is exercised on both lines with external pull-up resistors. The value of these resistors is system dependent. Normally, a standard communication is composed of four parts: • START signal • Slave address transmission • Data transfer • STOP signal The STOP signal should not be confused with the CPU STOP instruction. The IIC bus system communication is described briefly in the following sections and illustrated in Figure 13-8. MSB SCL SDA 1 LSB 2 3 4 5 6 7 START SIGNAL 1 XXX 3 4 5 2 3 4 5 6 7 8 D7 D6 D5 D4 D3 D2 D1 D0 6 7 8 9 READ/ ACK WRITE BIT 1 XX 9 NO STOP ACK SIGNAL BIT MSB AD7 AD6 AD5 AD4 AD3 AD2 AD1 R/W CALLING ADDRESS 1 DATA BYTE LSB 2 LSB READ/ ACK WRITE BIT CALLING ADDRESS MSB SDA 9 AD7 AD6 AD5 AD4 AD3 AD2 AD1 R/W START SIGNAL SCL 8 MSB LSB 2 3 4 5 6 7 8 9 AD7 AD6 AD5 AD4 AD3 AD2 AD1 R/W REPEATED START SIGNAL NEW CALLING ADDRESS READ/ NO STOP SIGNAL WRITE ACK BIT Figure 13-8. IIC Bus Transmission Signals MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 225 Inter-Integrated Circuit (S08IICV1) 13.4.1.1 START Signal When the bus is free; i.e., no master device is engaging the bus (both SCL and SDA lines are at logical high), a master may initiate communication by sending a START signal. As shown in Figure 13-8, a START signal is defined as a high-to-low transition of SDA while SCL is high. This signal denotes the beginning of a new data transfer (each data transfer may contain several bytes of data) and brings all slaves out of their idle states. 13.4.1.2 Slave Address Transmission The first byte of data transferred immediately after the START signal is the slave address transmitted by the master. This is a seven-bit calling address followed by a R/W bit. The R/W bit tells the slave the desired direction of data transfer. 1 = Read transfer, the slave transmits data to the master. 0 = Write transfer, the master transmits data to the slave. Only the slave with a calling address that matches the one transmitted by the master will respond by sending back an acknowledge bit. This is done by pulling the SDA low at the 9th clock (see Figure 13-8). No two slaves in the system may have the same address. If the IIC module is the master, it must not transmit an address that is equal to its own slave address. The IIC cannot be master and slave at the same time. However, if arbitration is lost during an address cycle, the IIC will revert to slave mode and operate correctly even if it is being addressed by another master. 13.4.1.3 Data Transfer Before successful slave addressing is achieved, the data transfer can proceed byte-by-byte in a direction specified by the R/W bit sent by the calling master. All transfers that come after an address cycle are referred to as data transfers, even if they carry sub-address information for the slave device Each data byte is 8 bits long. Data may be changed only while SCL is low and must be held stable while SCL is high as shown in Figure 13-8. There is one clock pulse on SCL for each data bit, the MSB being transferred first. Each data byte is followed by a 9th (acknowledge) bit, which is signalled from the receiving device. An acknowledge is signalled by pulling the SDA low at the ninth clock. In summary, one complete data transfer needs nine clock pulses. If the slave receiver does not acknowledge the master in the 9th bit time, the SDA line must be left high by the slave. The master interprets the failed acknowledge as an unsuccessful data transfer. If the master receiver does not acknowledge the slave transmitter after a data byte transmission, the slave interprets this as an end of data transfer and releases the SDA line. In either case, the data transfer is aborted and the master does one of two things: • Relinquishes the bus by generating a STOP signal. • Commences a new calling by generating a repeated START signal. MC9S08AW60 Data Sheet, Rev.1.0 226 Freescale Semiconductor Inter-Integrated Circuit (S08IICV1) 13.4.1.4 STOP Signal The master can terminate the communication by generating a STOP signal to free the bus. However, the master may generate a START signal followed by a calling command without generating a STOP signal first. This is called repeated START. A STOP signal is defined as a low-to-high transition of SDA while SCL at logical 1 (see Figure 13-8). The master can generate a STOP even if the slave has generated an acknowledge at which point the slave must release the bus. 13.4.1.5 Repeated START Signal As shown in Figure 13-8, a repeated START signal is a START signal generated without first generating a STOP signal to terminate the communication. This is used by the master to communicate with another slave or with the same slave in different mode (transmit/receive mode) without releasing the bus. 13.4.1.6 Arbitration Procedure The IIC bus is a true multi-master bus that allows more than one master to be connected on it. If two or more masters try to control the bus at the same time, a clock synchronization procedure determines the bus clock, for which the low period is equal to the longest clock low period and the high is equal to the shortest one among the masters. The relative priority of the contending masters is determined by a data arbitration procedure, a bus master loses arbitration if it transmits logic 1 while another master transmits logic 0. The losing masters immediately switch over to slave receive mode and stop driving SDA output. In this case, the transition from master to slave mode does not generate a STOP condition. Meanwhile, a status bit is set by hardware to indicate loss of arbitration. 13.4.1.7 Clock Synchronization Because wire-AND logic is performed on the SCL line, a high-to-low transition on the SCL line affects all the devices connected on the bus. The devices start counting their low period and after a device’s clock has gone low, it holds the SCL line low until the clock high state is reached. However, the change of low to high in this device clock may not change the state of the SCL line if another device clock is still within its low period. Therefore, synchronized clock SCL is held low by the device with the longest low period. Devices with shorter low periods enter a high wait state during this time (see Figure 13-9). When all devices concerned have counted off their low period, the synchronized clock SCL line is released and pulled high. There is then no difference between the device clocks and the state of the SCL line and all the devices start counting their high periods. The first device to complete its high period pulls the SCL line low again. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 227 Inter-Integrated Circuit (S08IICV1) DELAY START COUNTING HIGH PERIOD SCL1 SCL2 SCL INTERNAL COUNTER RESET Figure 13-9. IIC Clock Synchronization 13.4.1.8 Handshaking The clock synchronization mechanism can be used as a handshake in data transfer. Slave devices may hold the SCL low after completion of one byte transfer (9 bits). In such case, it halts the bus clock and forces the master clock into wait states until the slave releases the SCL line. 13.4.1.9 Clock Stretching The clock synchronization mechanism can be used by slaves to slow down the bit rate of a transfer. After the master has driven SCL low the slave can drive SCL low for the required period and then release it. If the slave SCL low period is greater than the master SCL low period then the resulting SCL bus signal low period is stretched. 13.5 Resets The IIC is disabled after reset. The IIC cannot cause an MCU reset. 13.6 Interrupts The IIC generates a single interrupt. An interrupt from the IIC is generated when any of the events in Table 13-7 occur provided the IICIE bit is set. The interrupt is driven by bit IICIF (of the IIC status register) and masked with bit IICIE (of the IIC control register). The IICIF bit must be cleared by software by writing a one to it in the interrupt routine. The user can determine the interrupt type by reading the status register. Table 13-7. Interrupt Summary Interrupt Source Status Flag Local Enable Complete 1-byte transfer TCF IICIF IICIE Match of received calling address IAAS IICIF IICIE Arbitration Lost ARBL IICIF IICIE MC9S08AW60 Data Sheet, Rev.1.0 228 Freescale Semiconductor Inter-Integrated Circuit (S08IICV1) 13.6.1 Byte Transfer Interrupt The TCF (transfer complete flag) bit is set at the falling edge of the 9th clock to indicate the completion of byte transfer. 13.6.2 Address Detect Interrupt When the calling address matches the programmed slave address (IIC address register), the IAAS bit in the status register is set. The CPU is interrupted provided the IICIE is set. The CPU must check the SRW bit and set its Tx mode accordingly. 13.6.3 Arbitration Lost Interrupt The IIC is a true multi-master bus that allows more than one master to be connected on it. If two or more masters try to control the bus at the same time, the relative priority of the contending masters is determined by a data arbitration procedure. The IIC module asserts this interrupt when it loses the data arbitration process and the ARBL bit in the status register is set. Arbitration is lost in the following circumstances: • SDA sampled as a low when the master drives a high during an address or data transmit cycle. • SDA sampled as a low when the master drives a high during the acknowledge bit of a data receive cycle. • A START cycle is attempted when the bus is busy. • A repeated START cycle is requested in slave mode. • A STOP condition is detected when the master did not request it. This bit must be cleared by software by writing a one to it. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 229 Inter-Integrated Circuit (S08IICV1) MC9S08AW60 Data Sheet, Rev.1.0 230 Freescale Semiconductor Chapter 14 Analog-to-Digital Converter (S08ADC10V1) 14.1 Overview The 10-bit analog-to-digital converter (ADC) is a successive approximation ADC designed for operation within an integrated microcontroller system-on-chip. The ADC module design supports up to 28 separate analog inputs (AD0-AD27). Only 17 (AD0-AD15 and AD27) of the possible inputs are implemented on the MC9S08AW60/48/32/16 Family of MCUs. These inputs are selected by the ADCH bits. Some inputs are shared with I/O pins as shown in Figure 14-1. All of the channel assignments of the ADC for the MC9S08AW60/48/32/16 devices are summarized in Table 14-1. 14.2 Channel Assignments The ADC channel assignments for the MC9S08AW60/48/32/16 devices are shown in the table below. Channels that are unimplemented are internally connected to VREFL. Reserved channels convert to an unknown value. Channels which are connected to an I/O pin have an associated pin control bit as shown. Table 14-1. ADC Channel Assignment ADCH Channel Input Pin Control ADCH Channel Input Pin Control 00000 AD0 PTB0/ADC1P0 ADPC0 10000 AD16 VREFL N/A 00001 AD1 PTB1/ADC1P1 ADPC1 10001 AD17 VREFL N/A 00010 AD2 PTB2/ADC1P2 ADPC2 10010 AD18 VREFL N/A 00011 AD3 PTB3/ADC1P3 ADPC3 10011 AD19 VREFL N/A 00100 AD4 PTB4/ADC1P4 ADPC4 10100 AD20 VREFL N/A 00101 AD5 PTB5/ADC1P5 ADPC5 10101 AD21 VREFL N/A 00110 AD6 PTB6/ADC1P6 ADPC6 10110 AD22 Reserved N/A 00111 AD7 PTB7/ADC1P7 ADPC7 10111 AD23 Reserved N/A 01000 AD8 PTD0/ADC1P8 ADPC8 11000 AD24 Reserved N/A 01001 AD9 PTD1/ADC1P9 ADPC9 11001 AD25 Reserved N/A 01010 AD10 PTD2/ADC1P10/ KBI1P5 ADPC10 11010 AD26 Reserved N/A 01011 AD11 PTD3/ADC1P11/ KBI1P6 ADPC11 11011 AD27 Internal Bandgap N/A 01100 AD12 PTD4/ADC1P12/ TPM2CLK ADPC12 11100 — Reserved N/A 01101 AD13 PTD5/ADC1P13 ADPC13 11101 VREFH VREFH N/A 01110 AD14 PTD6/ADC1P14/ TPM1CLK ADPC14 11110 VREFL VREFL N/A 01111 AD15 PTD7ADC1P15/ KBI1P7 ADPC15 11111 module disabled None N/A MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 231 Chapter 14 Analog-to-Digital Converter (S08ADC10V1) NOTE Selecting the internal bandgap channel requires BGBE =1 in SPMSC1 see Section 5.9.8, “System Power Management Status and Control 1 Register (SPMSC1).” For value of bandgap voltage reference see Section A.6, “DC Characteristics.” 14.2.1 Alternate Clock The ADC module is capable of performing conversions using the MCU bus clock, the bus clock divided by two, the local asynchronous clock (ADACK) within the module, or the alternate clock, ALTCLK. The alternate clock for the MC9S08AW60/48/32/16 MCU devices is the external reference clock (ICGERCLK) from the internal clock generator (ICG) module. Because ICGERCLK is active only while an external clock source is enabled, the ICG must be configured for either FBE or FEE mode (CLKS1 = 1). ICGERCLK must run at a frequency such that the ADC conversion clock (ADCK) runs at a frequency within its specified range (fADCK) after being divided down from the ALTCLK input as determined by the ADIV bits. For example, if the ADIV bits are set up to divide by four, then the minimum frequency for ALTCLK (ICGERCLK) is four times the minimum value for fADCK and the maximum frequency is four times the maximum value for fADCK. Because of the minimum frequency requirement, when an oscillator circuit is used it must be configured for high range operation (RANGE = 1). ALTCLK is active while the MCU is in wait mode provided the conditions described above are met. This allows ALTCLK to be used as the conversion clock source for the ADC while the MCU is in wait mode. ALTCLK cannot be used as the ADC conversion clock source while the MCU is in stop3. 14.2.2 Hardware Trigger The ADC hardware trigger, ADHWT, is output from the real time interrupt (RTI) counter. The RTI counter can be clocked by either ICGERCLK or a nominal 1 kHz clock source within the RTI block. The 1-kHz clock source can be used with the MCU in run, wait, or stop3. With the ICG configured for either FBE or FEE mode, ICGERCLK can be used with the MCU in run or wait. The period of the RTI is determined by the input clock frequency and the RTIS bits. When the ADC hardware trigger is enabled, a conversion is initiated upon an RTI counter overflow. The RTI counter is a free running counter that generates an overflow at the RTI rate determined by the RTIS bits. 14.2.2.1 Analog Pin Enables The ADC on MC9S08AW60/48/32/16 contains only two analog pin enable registers, APCTL1 and APCTL2. 14.2.2.2 Low-Power Mode Operation The ADC is capable of running in stop3 mode but requires LVDSE and LVDE in SPMSC1 to be set. MC9S08AW60 Data Sheet, Rev.1.0 232 Freescale Semiconductor HCS08 CORE BDC DEBUG MODULE (DBG) RTI COP IRQ LVD SERIAL COMMUNICATIONS INTERFACE MODULE (SCI2) IIC MODULE (IIC1) 10-BIT ANALOG-TO-DIGITAL CONVERTER (ADC1) TxD2 SDA1 SCL1 LOW-POWER OSCILLATOR SERIAL COMMUNICATIONS INTERFACE MODULE (SCI1) VOLTAGE REGULATOR 2-CHANNEL TIMER/PWM MODULE (TPM2) PTE7/SPSCK1 MISO1 SS1 TPM1CLK TPM1CH5– TPM1CH0 RxD1 TxD1 PORT E INTERNAL CLOCK GENERATOR (ICG) 6-CHANNEL TIMER/PWM MODULE (TPM1) SPSCK1 MOSI1 6 TPM2CLK PORT F USER RAM AW60/48/32 = 2048 BYTES AW16 = 1024 BYTES PTD7/AD1P15/KBI1P7 PTD6/AD1P14/TPM1CLK PTD5/AD1P13 PTD4/AD1P12/TPM2CLK PTD3/AD1P11/KBI1P6 PTD2/AD1P10/KBI1P5 PTD1/AD1P9 PTD0/AD1P8 8 8 AD1P15–AD1P8 USER FLASH (AW60 = 63,280 BYTES) (AW48 = 49,152 BYTES) (AW32 = 32,768 BYTES) (AW16 = 16,384 BYTES) SERIAL PERIPHERAL INTERFACE MODULE (SPI1) PTC6 PTC5/RxD2 PTC4 PTC3/TxD2 PTC2/MCLK PTC1/SDA1 PTC0/SCL1 RxD2 AD1P7–AD1P0 VSSAD VREFL VREFH VSS PTB7/AD1P7– PTB0/AD1P0 PORT C RESETS AND INTERRUPTS MODES OF OPERATION POWER MANAGEMENT VDDAD VDD 8 PORT D IRQ PTA7– PTA0 HCS08 SYSTEM CONTROL TPM2CH1–TPM2CH0 2 KBI1P7–KBI1P5 3 8-BIT KEYBOARD INTERRUPT MODULE (KBI1) KBI1P4–KBI1P0 EXTAL XTAL NOTES: 1. Port pins are software configurable with pullup device if input port. 2. Pin contains software configurable pullup/pulldown device if IRQ is enabled (IRQPE = 1). Pulldown is enabled if rising edge detect is selected (IRQEDG = 1) 3. IRQ does not have a clamp diode to VDD. IRQ should not be driven above VDD. 4. Pin contains integrated pullup device. 5. Pins PTD7, PTD3, PTD2, and PTG4 contain both pullup and pulldown devices. Pulldown enabled when KBI is enabled (KBIPEn = 1) and rising edge is selected (KBEDGn = 1). 5 PORT G RESET 8 CPU PORT B BKGD/MS PORT A Chapter 14 Analog-to-Digital Converter (S08ADC10V1) PTE6/MOSI1 PTE5/MISO1 PTE4/SS1 PTE3/TPM1CH1 PTE2/TPM1CH0 PTE1/RxD1 PTE0/TxD1 PTF7 PTF6 PTF5/TPM2CH1 PTF4/TPM2CH0 PTF3/TPM1CH5 PTF2/TPM1CH4 PTF1/TPM1CH3 PTF0/TPM1CH2 PTG6/EXTAL PTG5/XTAL PTG4/KBI1P4 PTG3/KBI1P3 PTG2/KBI1P2 PTG1/KBI1P1 PTG0/KBI1P0 Figure 14-1. MC9S08AW60 Block Diagram Highlighting ADC Block and Pins MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 233 Analog-to-Digital Converter (S08ADC10V1) 14.2.3 Features Features of the ADC module include: • Linear successive approximation algorithm with 10 bits resolution. • Up to 28 analog inputs. • Output formatted in 10- or 8-bit right-justified format. • Single or continuous conversion (automatic return to idle after single conversion). • Configurable sample time and conversion speed/power. • Conversion complete flag and interrupt. • Input clock selectable from up to four sources. • Operation in wait or stop3 modes for lower noise operation. • Asynchronous clock source for lower noise operation. • Selectable asynchronous hardware conversion trigger. • Automatic compare with interrupt for less-than, or greater-than or equal-to, programmable value. 14.2.4 Block Diagram Figure 14-2 provides a block diagram of the ADC module MC9S08AW60 Data Sheet, Rev.1.0 234 Freescale Semiconductor Analog-to-Digital Converter (S08ADC10V1) ADIV ADLPC MODE ADLSMP ADTRG 2 ADCO ADCH 1 ADC1CFG complete COCO ADC1SC1 ADICLK Compare true AIEN 3 Async Clock Gen ADACK MCU STOP ADCK ÷2 ALTCLK abort transfer sample initialize ••• AD0 convert Control Sequencer ADHWT Bus Clock Clock Divide AIEN 1 Interrupt COCO 2 ADVIN SAR Converter AD27 VREFH Data Registers Sum VREFL Compare true 3 Compare Value Registers ACFGT Value Compare Logic ADC1SC2 Figure 14-2. ADC Block Diagram 14.3 External Signal Description The ADC module supports up to 28 separate analog inputs. It also requires four supply/reference/ground connections. Table 14-2. Signal Properties Name Function AD27–AD0 Analog Channel inputs VREFH High reference voltage VREFL Low reference voltage VDDAD Analog power supply VSSAD Analog ground MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 235 Analog-to-Digital Converter (S08ADC10V1) 14.3.1 Analog Power (VDDAD) The ADC analog portion uses VDDAD as its power connection. In some packages, VDDAD is connected internally to VDD. If externally available, connect the VDDAD pin to the same voltage potential as VDD. External filtering may be necessary to ensure clean VDDAD for good results. 14.3.2 Analog Ground (VSSAD) The ADC analog portion uses VSSAD as its ground connection. In some packages, VSSAD is connected internally to VSS. If externally available, connect the VSSAD pin to the same voltage potential as VSS. 14.3.3 Voltage Reference High (VREFH) VREFH is the high reference voltage for the converter. In some packages, VREFH is connected internally to VDDAD. If externally available, VREFH may be connected to the same potential as VDDAD, or may be driven by an external source that is between the minimum VDDAD spec and the VDDAD potential (VREFH must never exceed VDDAD). 14.3.4 Voltage Reference Low (VREFL) VREFL is the low reference voltage for the converter. In some packages, VREFL is connected internally to VSSAD. If externally available, connect the VREFL pin to the same voltage potential as VSSAD. 14.3.5 Analog Channel Inputs (ADx) The ADC module supports up to 28 separate analog inputs. An input is selected for conversion through the ADCH channel select bits. 14.4 Register Definition These memory mapped registers control and monitor operation of the ADC: • • • • • • Status and control register, ADC1SC1 Status and control register, ADC1SC2 Data result registers, ADC1RH and ADC1RL Compare value registers, ADC1CVH and ADC1CVL Configuration register, ADC1CFG Pin enable registers, APCTL1, APCTL2, APCTL3 14.4.1 Status and Control Register 1 (ADC1SC1) This section describes the function of the ADC status and control register (ADC1SC1). Writing ADC1SC1 aborts the current conversion and initiates a new conversion (if the ADCH bits are equal to a value other than all 1s). MC9S08AW60 Data Sheet, Rev.1.0 236 Freescale Semiconductor Analog-to-Digital Converter (S08ADC10V1) 7 R 6 5 4 AIEN ADCO 0 0 3 2 1 0 1 1 COCO ADCH W Reset: 0 1 1 1 = Unimplemented or Reserved Figure 14-3. Status and Control Register (ADC1SC1) Table 14-3. ADC1SC1 Register Field Descriptions Field Description 7 COCO Conversion Complete Flag — The COCO flag is a read-only bit which is set each time a conversion is completed when the compare function is disabled (ACFE = 0). When the compare function is enabled (ACFE = 1) the COCO flag is set upon completion of a conversion only if the compare result is true. This bit is cleared whenever ADC1SC1 is written or whenever ADC1RL is read. 0 Conversion not completed 1 Conversion completed 6 AIEN Interrupt Enable — AIEN is used to enable conversion complete interrupts. When COCO becomes set while AIEN is high, an interrupt is asserted. 0 Conversion complete interrupt disabled 1 Conversion complete interrupt enabled 5 ADCO Continuous Conversion Enable — ADCO is used to enable continuous conversions. 0 One conversion following a write to the ADC1SC1 when software triggered operation is selected, or one conversion following assertion of ADHWT when hardware triggered operation is selected. 1 Continuous conversions initiated following a write to ADC1SC1 when software triggered operation is selected. Continuous conversions are initiated by an ADHWT event when hardware triggered operation is selected. 4:0 ADCH Input Channel Select — The ADCH bits form a 5-bit field which is used to select one of the input channels. The input channels are detailed in Figure 14-4. The successive approximation converter subsystem is turned off when the channel select bits are all set to 1. This feature allows for explicit disabling of the ADC and isolation of the input channel from all sources. Terminating continuous conversions this way will prevent an additional, single conversion from being performed. It is not necessary to set the channel select bits to all 1s to place the ADC in a low-power state when continuous conversions are not enabled because the module automatically enters a low-power state when a conversion completes. Figure 14-4. Input Channel Select ADCH Input Select ADCH Input Select 00000 AD0 10000 AD16 00001 AD1 10001 AD17 00010 AD2 10010 AD18 00011 AD3 10011 AD19 00100 AD4 10100 AD20 00101 AD5 10101 AD21 00110 AD6 10110 AD22 00111 AD7 10111 AD23 MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 237 Analog-to-Digital Converter (S08ADC10V1) Figure 14-4. Input Channel Select (continued) 14.4.2 ADCH Input Select ADCH Input Select 01000 AD8 11000 AD24 01001 AD9 11001 AD25 01010 AD10 11010 AD26 01011 AD11 11011 AD27 01100 AD12 11100 Reserved 01101 AD13 11101 VREFH 01110 AD14 11110 VREFL 01111 AD15 11111 Module disabled Status and Control Register 2 (ADC1SC2) The ADC1SC2 register is used to control the compare function, conversion trigger and conversion active of the ADC module. 7 R 6 5 4 ADTRG ACFE ACFGT 0 0 0 ADACT 3 2 0 0 0 0 1 0 R1 R1 0 0 W Reset: 0 = Unimplemented or Reserved 1 Bits 1 and 0 are reserved bits that must always be written to 0. Figure 14-5. Status and Control Register 2 (ADC1SC2) Table 14-4. ADC1SC2 Register Field Descriptions Field Description 7 ADACT Conversion Active — ADACT indicates that a conversion is in progress. ADACT is set when a conversion is initiated and cleared when a conversion is completed or aborted. 0 Conversion not in progress 1 Conversion in progress 6 ADTRG Conversion Trigger Select — ADTRG is used to select the type of trigger to be used for initiating a conversion. Two types of trigger are selectable: software trigger and hardware trigger. When software trigger is selected, a conversion is initiated following a write to ADC1SC1. When hardware trigger is selected, a conversion is initiated following the assertion of the ADHWT input. 0 Software trigger selected 1 Hardware trigger selected MC9S08AW60 Data Sheet, Rev.1.0 238 Freescale Semiconductor Analog-to-Digital Converter (S08ADC10V1) Table 14-4. ADC1SC2 Register Field Descriptions (continued) Field Description 5 ACFE Compare Function Enable — ACFE is used to enable the compare function. 0 Compare function disabled 1 Compare function enabled 4 ACFGT Compare Function Greater Than Enable — ACFGT is used to configure the compare function to trigger when the result of the conversion of the input being monitored is greater than or equal to the compare value. The compare function defaults to triggering when the result of the compare of the input being monitored is less than the compare value. 0 Compare triggers when input is less than compare level 1 Compare triggers when input is greater than or equal to compare level 14.4.3 Data Result High Register (ADC1RH) ADC1RH contains the upper two bits of the result of a 10-bit conversion. When configured for 8-bit conversions both ADR8 and ADR9 are equal to zero. ADC1RH is updated each time a conversion completes except when automatic compare is enabled and the compare condition is not met. In 10-bit MODE, reading ADC1RH prevents the ADC from transferring subsequent conversion results into the result registers until ADC1RL is read. If ADC1RL is not read until after the next conversion is completed, then the intermediate conversion result will be lost. In 8-bit mode there is no interlocking with ADC1RL. In the case that the MODE bits are changed, any data in ADC1RH becomes invalid. R 7 6 5 4 3 2 1 0 0 0 0 0 0 0 ADR9 ADR8 0 0 0 0 0 0 0 0 W Reset: = Unimplemented or Reserved Figure 14-6. Data Result High Register (ADC1RH) 14.4.4 Data Result Low Register (ADC1RL) ADC1RL contains the lower eight bits of the result of a 10-bit conversion, and all eight bits of an 8-bit conversion. This register is updated each time a conversion completes except when automatic compare is enabled and the compare condition is not met. In 10-bit mode, reading ADC1RH prevents the ADC from transferring subsequent conversion results into the result registers until ADC1RL is read. If ADC1RL is not read until the after next conversion is completed, then the intermediate conversion results will be lost. In 8-bit mode, there is no interlocking with ADC1RH. In the case that the MODE bits are changed, any data in ADC1RL becomes invalid. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 239 Analog-to-Digital Converter (S08ADC10V1) R 7 6 5 4 3 2 1 0 ADR7 ADR6 ADR5 ADR4 ADR3 ADR2 ADR1 ADR0 0 0 0 0 0 0 0 0 W Reset: = Unimplemented or Reserved Figure 14-7. Data Result Low Register (ADC1RL) 14.4.5 Compare Value High Register (ADC1CVH) This register holds the upper two bits of the 10-bit compare value. These bits are compared to the upper two bits of the result following a conversion in 10-bit mode when the compare function is enabled.In 8-bit operation, ADC1CVH is not used during compare. R 7 6 5 4 0 0 0 0 3 2 1 0 ADCV9 ADCV8 0 0 W Reset: 0 0 0 0 0 0 = Unimplemented or Reserved Figure 14-8. Compare Value High Register (ADC1CVH) 14.4.6 Compare Value Low Register (ADC1CVL) This register holds the lower 8 bits of the 10-bit compare value, or all 8 bits of the 8-bit compare value. Bits ADCV7:ADCV0 are compared to the lower 8 bits of the result following a conversion in either 10-bit or 8-bit mode. 7 6 5 4 3 2 1 0 ADCV7 ADCV6 ADCV5 ADCV4 ADCV3 ADCV2 ADCV1 ADCV0 0 0 0 0 0 0 0 0 R W Reset: Figure 14-9. Compare Value Low Register(ADC1CVL) 14.4.7 Configuration Register (ADC1CFG) ADC1CFG is used to select the mode of operation, clock source, clock divide, and configure for low power or long sample time. MC9S08AW60 Data Sheet, Rev.1.0 240 Freescale Semiconductor Analog-to-Digital Converter (S08ADC10V1) 7 6 5 4 3 2 1 0 R ADLPC ADIV ADLSMP MODE ADICLK W Reset: 0 0 0 0 0 0 0 0 Figure 14-10. Configuration Register (ADC1CFG) Table 14-5. ADC1CFG Register Field Descriptions Field Description 7 ADLPC Low Power Configuration — ADLPC controls the speed and power configuration of the successive approximation converter. This is used to optimize power consumption when higher sample rates are not required. 0 High speed configuration 1 Low power configuration: {FC31}The power is reduced at the expense of maximum clock speed. 6:5 ADIV Clock Divide Select — ADIV select the divide ratio used by the ADC to generate the internal clock ADCK. Table 14-6 shows the available clock configurations. 4 ADLSMP Long Sample Time Configuration — ADLSMP selects between long and short sample time. This adjusts the sample period to allow higher impedance inputs to be accurately sampled or to maximize conversion speed for lower impedance inputs. Longer sample times can also be used to lower overall power consumption when continuous conversions are enabled if high conversion rates are not required. 0 Short sample time 1 Long sample time 3:2 MODE Conversion Mode Selection — MODE bits are used to select between 10- or 8-bit operation. See Table 14-7. 1:0 ADICLK Input Clock Select — ADICLK bits select the input clock source to generate the internal clock ADCK. See Table 14-8. Table 14-6. Clock Divide Select ADIV Divide Ratio Clock Rate 00 1 Input clock 01 2 Input clock ÷ 2 10 4 Input clock ÷ 4 11 8 Input clock ÷ 8 Table 14-7. Conversion Modes MODE Mode Description 00 8-bit conversion (N=8) 01 Reserved 10 10-bit conversion (N=10) 11 Reserved MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 241 Analog-to-Digital Converter (S08ADC10V1) Table 14-8. Input Clock Select ADICLK 14.4.8 Selected Clock Source 00 Bus clock 01 Bus clock divided by 2 10 Alternate clock (ALTCLK) 11 Asynchronous clock (ADACK) Pin Control 1 Register (APCTL1) The pin control registers are used to disable the I/O port control of MCU pins used as analog inputs. APCTL1 is used to control the pins associated with channels 0–7 of the ADC module. 7 6 5 4 3 2 1 0 ADPC7 ADPC6 ADPC5 ADPC4 ADPC3 ADPC2 ADPC1 ADPC0 0 0 0 0 0 0 0 0 R W Reset: Figure 14-11. Pin Control 1 Register (APCTL1) Table 14-9. APCTL1 Register Field Descriptions Field Description 7 ADPC7 ADC Pin Control 7 — ADPC7 is used to control the pin associated with channel AD7. 0 AD7 pin I/O control enabled 1 AD7 pin I/O control disabled 6 ADPC6 ADC Pin Control 6 — ADPC6 is used to control the pin associated with channel AD6. 0 AD6 pin I/O control enabled 1 AD6 pin I/O control disabled 5 ADPC5 ADC Pin Control 5 — ADPC5 is used to control the pin associated with channel AD5. 0 AD5 pin I/O control enabled 1 AD5 pin I/O control disabled 4 ADPC4 ADC Pin Control 4 — ADPC4 is used to control the pin associated with channel AD4. 0 AD4 pin I/O control enabled 1 AD4 pin I/O control disabled 3 ADPC3 ADC Pin Control 3 — ADPC3 is used to control the pin associated with channel AD3. 0 AD3 pin I/O control enabled 1 AD3 pin I/O control disabled 2 ADPC2 ADC Pin Control 2 — ADPC2 is used to control the pin associated with channel AD2. 0 AD2 pin I/O control enabled 1 AD2 pin I/O control disabled MC9S08AW60 Data Sheet, Rev.1.0 242 Freescale Semiconductor Analog-to-Digital Converter (S08ADC10V1) Table 14-9. APCTL1 Register Field Descriptions (continued) Field Description 1 ADPC1 ADC Pin Control 1 — ADPC1 is used to control the pin associated with channel AD1. 0 AD1 pin I/O control enabled 1 AD1 pin I/O control disabled 0 ADPC0 ADC Pin Control 0 — ADPC0 is used to control the pin associated with channel AD0. 0 AD0 pin I/O control enabled 1 AD0 pin I/O control disabled 14.4.9 Pin Control 2 Register (APCTL2) APCTL2 is used to control channels 8–15 of the ADC module. 7 6 5 4 3 2 1 0 ADPC15 ADPC14 ADPC13 ADPC12 ADPC11 ADPC10 ADPC9 ADPC8 0 0 0 0 0 0 0 0 R W Reset: Figure 14-12. Pin Control 2 Register (APCTL2) Table 14-10. APCTL2 Register Field Descriptions Field Description 7 ADPC15 ADC Pin Control 15 — ADPC15 is used to control the pin associated with channel AD15. 0 AD15 pin I/O control enabled 1 AD15 pin I/O control disabled 6 ADPC14 ADC Pin Control 14 — ADPC14 is used to control the pin associated with channel AD14. 0 AD14 pin I/O control enabled 1 AD14 pin I/O control disabled 5 ADPC13 ADC Pin Control 13 — ADPC13 is used to control the pin associated with channel AD13. 0 AD13 pin I/O control enabled 1 AD13 pin I/O control disabled 4 ADPC12 ADC Pin Control 12 — ADPC12 is used to control the pin associated with channel AD12. 0 AD12 pin I/O control enabled 1 AD12 pin I/O control disabled 3 ADPC11 ADC Pin Control 11 — ADPC11 is used to control the pin associated with channel AD11. 0 AD11 pin I/O control enabled 1 AD11 pin I/O control disabled 2 ADPC10 ADC Pin Control 10 — ADPC10 is used to control the pin associated with channel AD10. 0 AD10 pin I/O control enabled 1 AD10 pin I/O control disabled MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 243 Analog-to-Digital Converter (S08ADC10V1) Table 14-10. APCTL2 Register Field Descriptions (continued) Field Description 1 ADPC9 ADC Pin Control 9 — ADPC9 is used to control the pin associated with channel AD9. 0 AD9 pin I/O control enabled 1 AD9 pin I/O control disabled 0 ADPC8 ADC Pin Control 8 — ADPC8 is used to control the pin associated with channel AD8. 0 AD8 pin I/O control enabled 1 AD8 pin I/O control disabled 14.4.10 Pin Control 3 Register (APCTL3) APCTL3 is used to control channels 16–23 of the ADC module. 7 6 5 4 3 2 1 0 ADPC23 ADPC22 ADPC21 ADPC20 ADPC19 ADPC18 ADPC17 ADPC16 0 0 0 0 0 0 0 0 R W Reset: Figure 14-13. Pin Control 3 Register (APCTL3) Table 14-11. APCTL3 Register Field Descriptions Field Description 7 ADPC23 ADC Pin Control 23 — ADPC23 is used to control the pin associated with channel AD23. 0 AD23 pin I/O control enabled 1 AD23 pin I/O control disabled 6 ADPC22 ADC Pin Control 22 — ADPC22 is used to control the pin associated with channel AD22. 0 AD22 pin I/O control enabled 1 AD22 pin I/O control disabled 5 ADPC21 ADC Pin Control 21 — ADPC21 is used to control the pin associated with channel AD21. 0 AD21 pin I/O control enabled 1 AD21 pin I/O control disabled 4 ADPC20 ADC Pin Control 20 — ADPC20 is used to control the pin associated with channel AD20. 0 AD20 pin I/O control enabled 1 AD20 pin I/O control disabled 3 ADPC19 ADC Pin Control 19 — ADPC19 is used to control the pin associated with channel AD19. 0 AD19 pin I/O control enabled 1 AD19 pin I/O control disabled 2 ADPC18 ADC Pin Control 18 — ADPC18 is used to control the pin associated with channel AD18. 0 AD18 pin I/O control enabled 1 AD18 pin I/O control disabled MC9S08AW60 Data Sheet, Rev.1.0 244 Freescale Semiconductor Analog-to-Digital Converter (S08ADC10V1) Table 14-11. APCTL3 Register Field Descriptions (continued) Field Description 1 ADPC17 ADC Pin Control 17 — ADPC17 is used to control the pin associated with channel AD17. 0 AD17 pin I/O control enabled 1 AD17 pin I/O control disabled 0 ADPC16 ADC Pin Control 16 — ADPC16 is used to control the pin associated with channel AD16. 0 AD16 pin I/O control enabled 1 AD16 pin I/O control disabled 14.5 Functional Description The ADC module is disabled during reset or when the ADCH bits are all high. The module is idle when a conversion has completed and another conversion has not been initiated. When idle, the module is in its lowest power state. The ADC can perform an analog-to-digital conversion on any of the software selectable channels. The selected channel voltage is converted by a successive approximation algorithm into an 11-bit digital result. In 8-bit mode, the selected channel voltage is converted by a successive approximation algorithm into a 9-bit digital result. When the conversion is completed, the result is placed in the data registers (ADC1RH and ADC1RL).In 10-bit mode, the result is rounded to 10 bits and placed in ADC1RH and ADC1RL. In 8-bit mode, the result is rounded to 8 bits and placed in ADC1RL. The conversion complete flag (COCO) is then set and an interrupt is generated if the conversion complete interrupt has been enabled (AIEN = 1). The ADC module has the capability of automatically comparing the result of a conversion with the contents of its compare registers. The compare function is enabled by setting the ACFE bit and operates in conjunction with any of the conversion modes and configurations. 14.5.1 Clock Select and Divide Control One of four clock sources can be selected as the clock source for the ADC module. This clock source is then divided by a configurable value to generate the input clock to the converter (ADCK). The clock is selected from one of the following sources by means of the ADICLK bits. • The bus clock, which is equal to the frequency at which software is executed. This is the default selection following reset. • The bus clock divided by 2. For higher bus clock rates, this allows a maximum divide by 16 of the bus clock. • ALTCLK, as defined for this MCU (See module section introduction). • The asynchronous clock (ADACK) – This clock is generated from a clock source within the ADC module. When selected as the clock source this clock remains active while the MCU is in wait or stop3 mode and allows conversions in these modes for lower noise operation. Whichever clock is selected, its frequency must fall within the specified frequency range for ADCK. If the available clocks are too slow, the ADC will not perform according to specifications. If the available clocks MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 245 Analog-to-Digital Converter (S08ADC10V1) are too fast, then the clock must be divided to the appropriate frequency. This divider is specified by the ADIV bits and can be divide-by 1, 2, 4, or 8. 14.5.2 Input Select and Pin Control The pin control registers (APCTL3, APCTL2, and APCTL1) are used to disable the I/O port control of the pins used as analog inputs.When a pin control register bit is set, the following conditions are forced for the associated MCU pin: • The output buffer is forced to its high impedance state. • The input buffer is disabled. A read of the I/O port returns a zero for any pin with its input buffer disabled. • The pullup is disabled. 14.5.3 Hardware Trigger The ADC module has a selectable asynchronous hardware conversion trigger, ADHWT, that is enabled when the ADTRG bit is set. This source is not available on all MCUs. Consult the module introduction for information on the ADHWT source specific to this MCU. When ADHWT source is available and hardware trigger is enabled (ADTRG=1), a conversion is initiated on the rising edge of ADHWT. If a conversion is in progress when a rising edge occurs, the rising edge is ignored. In continuous convert configuration, only the initial rising edge to launch continuous conversions is observed. The hardware trigger function operates in conjunction with any of the conversion modes and configurations. 14.5.4 Conversion Control Conversions can be performed in either 10-bit mode or 8-bit mode as determined by the MODE bits. Conversions can be initiated by either a software or hardware trigger. In addition, the ADC module can be configured for low power operation, long sample time, continuous conversion, and automatic compare of the conversion result to a software determined compare value. 14.5.4.1 Initiating Conversions A conversion is initiated: • Following a write to ADC1SC1 (with ADCH bits not all 1s) if software triggered operation is selected. • Following a hardware trigger (ADHWT) event if hardware triggered operation is selected. • Following the transfer of the result to the data registers when continuous conversion is enabled. If continuous conversions are enabled a new conversion is automatically initiated after the completion of the current conversion. In software triggered operation, continuous conversions begin after ADC1SC1 is written and continue until aborted. In hardware triggered operation, continuous conversions begin after a hardware trigger event and continue until aborted. MC9S08AW60 Data Sheet, Rev.1.0 246 Freescale Semiconductor Analog-to-Digital Converter (S08ADC10V1) 14.5.4.2 Completing Conversions A conversion is completed when the result of the conversion is transferred into the data result registers, ADC1RH and ADC1RL. This is indicated by the setting of COCO. An interrupt is generated if AIEN is high at the time that COCO is set. A blocking mechanism prevents a new result from overwriting previous data in ADC1RH and ADC1RL if the previous data is in the process of being read while in 12-bit or 10-bit MODE (the ADC1RH register has been read but the ADC1RL register has not). When blocking is active, the data transfer is blocked, COCO is not set, and the new result is lost. In the case of single conversions with the compare function enabled and the compare condition false, blocking has no effect and ADC operation is terminated. In all other cases of operation, when a data transfer is blocked, another conversion is initiated regardless of the state of ADCO (single or continuous conversions enabled). If single conversions are enabled, the blocking mechanism could result in several discarded conversions and excess power consumption. To avoid this issue, the data registers must not be read after initiating a single conversion until the conversion completes. 14.5.4.3 Aborting Conversions Any conversion in progress will be aborted when: • A write to ADC1SC1 occurs (the current conversion will be aborted and a new conversion will be initiated, if ADCH are not all 1s). • A write to ADC1SC2, ADC1CFG, ADC1CVH, or ADC1CVL occurs. This indicates a mode of operation change has occurred and the current conversion is therefore invalid. • The MCU is reset. • The MCU enters stop mode with ADACK not enabled. When a conversion is aborted, the contents of the data registers, ADC1RH and ADC1RL, are not altered but continue to be the values transferred after the completion of the last successful conversion. In the case that the conversion was aborted by a reset, ADC1RH and ADC1RL return to their reset states. 14.5.4.4 Power Control The ADC module remains in its idle state until a conversion is initiated. If ADACK is selected as the conversion clock source, the ADACK clock generator is also enabled. Power consumption when active can be reduced by setting ADLPC. This results in a lower maximum value for fADCK (see the electrical specifications). 14.5.4.5 Total Conversion Time The total conversion time depends on the sample time (as determined by ADLSMP), the MCU bus frequency, the conversion mode (8-bit or 10-bit), and the frequency of the conversion clock (fADCK). After the module becomes active, sampling of the input begins. ADLSMP is used to select between short and long sample times.When sampling is complete, the converter is isolated from the input channel and a successive approximation algorithm is performed to determine the digital value of the analog signal. The MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 247 Analog-to-Digital Converter (S08ADC10V1) result of the conversion is transferred to ADC1RH and ADC1RL upon completion of the conversion algorithm. If the bus frequency is less than the fADCK frequency, precise sample time for continuous conversions cannot be guaranteed when short sample is enabled (ADLSMP=0). If the bus frequency is less than 1/11th of the fADCK frequency, precise sample time for continuous conversions cannot be guaranteed when long sample is enabled (ADLSMP=1). The maximum total conversion time for different conditions is summarized in Table 14-12. Table 14-12. Total Conversion Time vs. Control Conditions Conversion Type ADICLK ADLSMP Max Total Conversion Time Single or first continuous 8-bit 0x, 10 0 20 ADCK cycles + 5 bus clock cycles Single or first continuous 10-bit 0x, 10 0 23 ADCK cycles + 5 bus clock cycles Single or first continuous 8-bit 0x, 10 1 40 ADCK cycles + 5 bus clock cycles Single or first continuous 10-bit 0x, 10 1 43 ADCK cycles + 5 bus clock cycles Single or first continuous 8-bit 11 0 5 µs + 20 ADCK + 5 bus clock cycles Single or first continuous 10-bit 11 0 5 µs + 23 ADCK + 5 bus clock cycles Single or first continuous 8-bit 11 1 5 µs + 40 ADCK + 5 bus clock cycles Single or first continuous 10-bit 11 1 5 µs + 43 ADCK + 5 bus clock cycles Subsequent continuous 8-bit; fBUS > fADCK xx 0 17 ADCK cycles Subsequent continuous 10-bit; fBUS > fADCK xx 0 20 ADCK cycles Subsequent continuous 8-bit; fBUS > fADCK/11 xx 1 37 ADCK cycles Subsequent continuous 10-bit; fBUS > fADCK/11 xx 1 40 ADCK cycles The maximum total conversion time is determined by the clock source chosen and the divide ratio selected. The clock source is selectable by the ADICLK bits, and the divide ratio is specified by the ADIV bits. For example, in 10-bit mode, with the bus clock selected as the input clock source, the input clock divide-by-1 ratio selected, and a bus frequency of 8 MHz, then the conversion time for a single conversion is: Conversion time = 23 ADCK cyc 8 MHz/1 + 5 bus cyc 8 MHz = 3.5 µs Number of bus cycles = 3.5 µs x 8 MHz = 28 cycles NOTE The ADCK frequency must be between fADCK minimum and fADCK maximum to meet ADC specifications. MC9S08AW60 Data Sheet, Rev.1.0 248 Freescale Semiconductor Analog-to-Digital Converter (S08ADC10V1) 14.5.5 Automatic Compare Function The compare function can be configured to check for either an upper limit or lower limit. After the input is sampled and converted, the result is added to the two’s complement of the compare value (ADC1CVH and ADC1CVL). When comparing to an upper limit (ACFGT = 1), if the result is greater-than or equal-to the compare value, COCO is set. When comparing to a lower limit (ACFGT = 0), if the result is less than the compare value, COCO is set. The value generated by the addition of the conversion result and the two’s complement of the compare value is transferred to ADC1RH and ADC1RL. Upon completion of a conversion while the compare function is enabled, if the compare condition is not true, COCO is not set and no data is transferred to the result registers. An ADC interrupt is generated upon the setting of COCO if the ADC interrupt is enabled (AIEN = 1). NOTE The compare function can be used to monitor the voltage on a channel while the MCU is in either wait or stop3 mode. The ADC interrupt will wake the MCU when the compare condition is met. 14.5.6 MCU Wait Mode Operation The WAIT instruction puts the MCU in a lower power-consumption standby mode from which recovery is very fast because the clock sources remain active. If a conversion is in progress when the MCU enters wait mode, it continues until completion. Conversions can be initiated while the MCU is in wait mode by means of the hardware trigger or if continuous conversions are enabled. The bus clock, bus clock divided by two, and ADACK are available as conversion clock sources while in wait mode. The use of ALTCLK as the conversion clock source in wait is dependent on the definition of ALTCLK for this MCU. Consult the module introduction for information on ALTCLK specific to this MCU. A conversion complete event sets the COCO and generates an ADC interrupt to wake the MCU from wait mode if the ADC interrupt is enabled (AIEN = 1). 14.5.7 MCU Stop3 Mode Operation The STOP instruction is used to put the MCU in a low power-consumption standby mode during which most or all clock sources on the MCU are disabled. 14.5.7.1 Stop3 Mode With ADACK Disabled If the asynchronous clock, ADACK, is not selected as the conversion clock, executing a STOP instruction aborts the current conversion and places the ADC in its idle state. The contents of ADC1RH and ADC1RL are unaffected by stop3 mode.After exiting from stop3 mode, a software or hardware trigger is required to resume conversions. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 249 Analog-to-Digital Converter (S08ADC10V1) 14.5.7.2 Stop3 Mode With ADACK Enabled If ADACK is selected as the conversion clock, the ADC continues operation during stop3 mode. For guaranteed ADC operation, the MCU’s voltage regulator must remain active during stop3 mode. Consult the module introduction for configuration information for this MCU. If a conversion is in progress when the MCU enters stop3 mode, it continues until completion. Conversions can be initiated while the MCU is in stop3 mode by means of the hardware trigger or if continuous conversions are enabled. A conversion complete event sets the COCO and generates an ADC interrupt to wake the MCU from stop3 mode if the ADC interrupt is enabled (AIEN = 1). NOTE It is possible for the ADC module to wake the system from low power stop and cause the MCU to begin consuming run-level currents without generating a system level interrupt. To prevent this scenario, software should ensure that the data transfer blocking mechanism (discussed in Section 14.5.4.2, “Completing Conversions) is cleared when entering stop3 and continuing ADC conversions. 14.5.8 MCU Stop1 and Stop2 Mode Operation The ADC module is automatically disabled when the MCU enters either stop1 or stop2 mode. All module registers contain their reset values following exit from stop1 or stop2. Therefore the module must be re-enabled and re-configured following exit from stop1 or stop2. 14.6 Initialization Information This section gives an example which provides some basic direction on how a user would initialize and configure the ADC module. The user has the flexibility of choosing between configuring the module for 8-bit or 10-bit resolution, single or continuous conversion, and a polled or interrupt approach, among many other options. Refer to Table 14-6, Table 14-7, and Table 14-8 for information used in this example. NOTE Hexadecimal values designated by a preceding 0x, binary values designated by a preceding %, and decimal values have no preceding character. 14.6.1 14.6.1.1 ADC Module Initialization Example Initialization Sequence Before the ADC module can be used to complete conversions, an initialization procedure must be performed. A typical sequence is as follows: 1. Update the configuration register (ADCCFG) to select the input clock source and the divide ratio used to generate the internal clock, ADCK. This register is also used for selecting sample time and low-power configuration. MC9S08AW60 Data Sheet, Rev.1.0 250 Freescale Semiconductor Analog-to-Digital Converter (S08ADC10V1) 2. Update status and control register 2 (ADCSC2) to select the conversion trigger (hardware or software) and compare function options, if enabled. 3. Update status and control register 1 (ADCSC1) to select whether conversions will be continuous or completed only once, and to enable or disable conversion complete interrupts. The input channel on which conversions will be performed is also selected here. 14.6.1.2 Pseudo — Code Example In this example, the ADC module will be set up with interrupts enabled to perform a single 10-bit conversion at low power with a long sample time on input channel 1, where the internal ADCK clock will be derived from the bus clock divided by 1. ADCCFG = 0x98 (%10011000) Bit 7 ADLPC 1 Configures for low power (lowers maximum clock speed) Bit 6:5 ADIV 00 Sets the ADCK to the input clock ÷ 1 Bit 4 ADLSMP 1 Configures for long sample time Bit 3:2 MODE 10 Sets mode at 10-bit conversions Bit 1:0 ADICLK 00 Selects bus clock as input clock source ADCSC2 = 0x00 (%00000000) Bit 7 ADACT 0 Bit 6 ADTRG 0 Bit 5 ACFE 0 Bit 4 ACFGT 0 Bit 3:2 00 Bit 1:0 00 Flag indicates if a conversion is in progress Software trigger selected Compare function disabled Not used in this example Unimplemented or reserved, always reads zero Reserved for Freescale’s internal use; always write zero ADCSC1 = 0x41 (%01000001) Bit 7 COCO 0 Bit 6 AIEN 1 Bit 5 ADCO 0 Bit 4:0 ADCH 00001 Read-only flag which is set when a conversion completes Conversion complete interrupt enabled One conversion only (continuous conversions disabled) Input channel 1 selected as ADC input channel ADCRH/L = 0xxx Holds results of conversion. Read high byte (ADCRH) before low byte (ADCRL) so that conversion data cannot be overwritten with data from the next conversion. ADCCVH/L = 0xxx Holds compare value when compare function enabled APCTL1=0x02 AD1 pin I/O control disabled. All other AD pins remain general purpose I/O pins APCTL2=0x00 All other AD pins remain general purpose I/O pins MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 251 Analog-to-Digital Converter (S08ADC10V1) RESET INITIALIZE ADC ADCCFG = $98 ADCSC2 = $00 ADCSC1 = $41 CHECK COCO=1? NO YES READ ADCRH THEN ADCRL TO CLEAR COCO BIT CONTINUE Figure 14-14. Initialization Flowchart for Example 14.7 Application Information This section contains information for using the ADC module in applications. The ADC has been designed to be integrated into a microcontroller for use in embedded control applications requiring an A/D converter. 14.7.1 External Pins and Routing The following sections discuss the external pins associated with the ADC module and how they should be used for best results. 14.7.1.1 Analog Supply Pins The ADC module has analog power and ground supplies (VDDAD and VSSAD) which are available as separate pins on some devices. On other devices, VSSAD is shared on the same pin as the MCU digital VSS, and on others, both VSSAD and VDDAD are shared with the MCU digital supply pins. In these cases, there are separate pads for the analog supplies which are bonded to the same pin as the corresponding digital supply so that some degree of isolation between the supplies is maintained. When available on a separate pin, both VDDAD and VSSAD must be connected to the same voltage potential as their corresponding MCU digital supply (VDD and VSS) and must be routed carefully for maximum noise immunity and bypass capacitors placed as near as possible to the package. MC9S08AW60 Data Sheet, Rev.1.0 252 Freescale Semiconductor Analog-to-Digital Converter (S08ADC10V1) In cases where separate power supplies are used for analog and digital power, the ground connection between these supplies must be at the VSSAD pin. This should be the only ground connection between these supplies if possible. The VSSAD pin makes a good single point ground location. 14.7.1.2 Analog Reference Pins In addition to the analog supplies, the ADC module has connections for two reference voltage inputs. The high reference is VREFH, which may be shared on the same pin as VDDAD on some devices. The low reference is VREFL, which may be shared on the same pin as VSSAD on some devices. When available on a separate pin, VREFH may be connected to the same potential as VDDAD, or may be driven by an external source that is between the minimum VDDAD spec and the VDDAD potential (VREFH must never exceed VDDAD). When available on a separate pin, VREFL must be connected to the same voltage potential as VSSAD. Both VREFH and VREFL must be routed carefully for maximum noise immunity and bypass capacitors placed as near as possible to the package. AC current in the form of current spikes required to supply charge to the capacitor array at each successive approximation step is drawn through the VREFH and VREFL loop. The best external component to meet this current demand is a 0.1 µF capacitor with good high frequency characteristics. This capacitor is connected between VREFH and VREFL and must be placed as near as possible to the package pins. Resistance in the path is not recommended because the current will cause a voltage drop which could result in conversion errors. Inductance in this path must be minimum (parasitic only). 14.7.1.3 Analog Input Pins The external analog inputs are typically shared with digital I/O pins on MCU devices. The pin I/O control is disabled by setting the appropriate control bit in one of the pin control registers. Conversions can be performed on inputs without the associated pin control register bit set. It is recommended that the pin control register bit always be set when using a pin as an analog input. This avoids problems with contention because the output buffer will be in its high impedance state and the pullup is disabled. Also, the input buffer draws dc current when its input is not at either VDD or VSS. Setting the pin control register bits for all pins used as analog inputs should be done to achieve lowest operating current. Empirical data shows that capacitors on the analog inputs improve performance in the presence of noise or when the source impedance is high. Use of 0.01 µF capacitors with good high-frequency characteristics is sufficient. These capacitors are not necessary in all cases, but when used they must be placed as near as possible to the package pins and be referenced to VSSA. For proper conversion, the input voltage must fall between VREFH and VREFL. If the input is equal to or exceeds VREFH, the converter circuit converts the signal to $3FF (full scale 10-bit representation) or $FF (full scale 8-bit representation). If the input is equal to or less than VREFL, the converter circuit converts it to $000. Input voltages between VREFH and VREFL are straight-line linear conversions. There will be a brief current associated with VREFL when the sampling capacitor is charging. The input is sampled for 3.5 cycles of the ADCK source when ADLSMP is low, or 23.5 cycles when ADLSMP is high. For minimal loss of accuracy due to current injection, pins adjacent to the analog input pins should not be transitioning during conversions. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 253 Analog-to-Digital Converter (S08ADC10V1) 14.7.2 Sources of Error Several sources of error exist for A/D conversions. These are discussed in the following sections. 14.7.2.1 Sampling Error For proper conversions, the input must be sampled long enough to achieve the proper accuracy. Given the maximum input resistance of approximately 7kΩ and input capacitance of approximately 5.5 pF, sampling to within 1/4LSB (at 10-bit resolution) can be achieved within the minimum sample window (3.5 cycles @ 8 MHz maximum ADCK frequency) provided the resistance of the external analog source (RAS) is kept below 5 kΩ. Higher source resistances or higher-accuracy sampling is possible by setting ADLSMP (to increase the sample window to 23.5 cycles) or decreasing ADCK frequency to increase sample time. 14.7.2.2 Pin Leakage Error Leakage on the I/O pins can cause conversion error if the external analog source resistance (RAS) is high. If this error cannot be tolerated by the application, keep RAS lower than VDDAD / (2N*ILEAK) for less than 1/4LSB leakage error (N = 8 in 8-bit mode or 10 in 10-bit mode). 14.7.2.3 Noise-Induced Errors System noise which occurs during the sample or conversion process can affect the accuracy of the conversion. The ADC accuracy numbers are guaranteed as specified only if the following conditions are met: • There is a 0.1 µF low-ESR capacitor from VREFH to VREFL. • There is a 0.1 µF low-ESR capacitor from VDDAD to VSSAD. • If inductive isolation is used from the primary supply, an additional 1 µF capacitor is placed from VDDAD to VSSAD. • VSSAD (and VREFL, if connected) is connected to VSS at a quiet point in the ground plane. • Operate the MCU in wait or stop3 mode before initiating (hardware triggered conversions) or immediately after initiating (hardware or software triggered conversions) the ADC conversion. — For software triggered conversions, immediately follow the write to the ADC1SC1 with a WAIT instruction or STOP instruction. — For stop3 mode operation, select ADACK as the clock source. Operation in stop3 reduces VDD noise but increases effective conversion time due to stop recovery. • There is no I/O switching, input or output, on the MCU during the conversion. There are some situations where external system activity causes radiated or conducted noise emissions or excessive VDD noise is coupled into the ADC. In these situations, or when the MCU cannot be placed in wait or stop3 or I/O activity cannot be halted, these recommended actions may reduce the effect of noise on the accuracy: • Place a 0.01 µF capacitor (CAS) on the selected input channel to VREFL or VSSAD (this will improve noise issues but will affect sample rate based on the external analog source resistance). MC9S08AW60 Data Sheet, Rev.1.0 254 Freescale Semiconductor Analog-to-Digital Converter (S08ADC10V1) • • Average the result by converting the analog input many times in succession and dividing the sum of the results. Four samples are required to eliminate the effect of a 1LSB, one-time error. Reduce the effect of synchronous noise by operating off the asynchronous clock (ADACK) and averaging. Noise that is synchronous to ADCK cannot be averaged out. 14.7.2.4 Code Width and Quantization Error The ADC quantizes the ideal straight-line transfer function into 1024 steps (in 10-bit mode). Each step ideally has the same height (1 code) and width. The width is defined as the delta between the transition points to one code and the next. The ideal code width for an N bit converter (in this case N can be 8 or 10), defined as 1LSB, is: 1LSB = (VREFH - VREFL) / 2N Eqn. 14-1 There is an inherent quantization error due to the digitization of the result. For 8-bit or 10-bit conversions the code will transition when the voltage is at the midpoint between the points where the straight line transfer function is exactly represented by the actual transfer function. Therefore, the quantization error will be ± 1/2LSB in 8- or 10-bit mode. As a consequence, however, the code width of the first ($000) conversion is only 1/2LSB and the code width of the last ($FF or $3FF) is 1.5LSB. 14.7.2.5 Linearity Errors The ADC may also exhibit non-linearity of several forms. Every effort has been made to reduce these errors but the system should be aware of them because they affect overall accuracy. These errors are: • Zero-scale error (EZS) (sometimes called offset) — This error is defined as the difference between the actual code width of the first conversion and the ideal code width (1/2LSB). Note, if the first conversion is $001, then the difference between the actual $001 code width and its ideal (1LSB) is used. • Full-scale error (EFS) — This error is defined as the difference between the actual code width of the last conversion and the ideal code width (1.5LSB). Note, if the last conversion is $3FE, then the difference between the actual $3FE code width and its ideal (1LSB) is used. • Differential non-linearity (DNL) — This error is defined as the worst-case difference between the actual code width and the ideal code width for all conversions. • Integral non-linearity (INL) — This error is defined as the highest-value the (absolute value of the) running sum of DNL achieves. More simply, this is the worst-case difference of the actual transition voltage to a given code and its corresponding ideal transition voltage, for all codes. • Total unadjusted error (TUE) — This error is defined as the difference between the actual transfer function and the ideal straight-line transfer function, and therefore includes all forms of error. 14.7.2.6 Code Jitter, Non-Monotonicity and Missing Codes Analog-to-digital converters are susceptible to three special forms of error. These are code jitter, non-monotonicity, and missing codes. Code jitter is when, at certain points, a given input voltage converts to one of two values when sampled repeatedly. Ideally, when the input voltage is infinitesimally smaller than the transition voltage, the MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 255 Analog-to-Digital Converter (S08ADC10V1) converter yields the lower code (and vice-versa). However, even very small amounts of system noise can cause the converter to be indeterminate (between two codes) for a range of input voltages around the transition voltage. This range is normally around 1/2LSB and will increase with noise. This error may be reduced by repeatedly sampling the input and averaging the result. Additionally the techniques discussed in Section 14.7.2.3 will reduce this error. Non-monotonicity is defined as when, except for code jitter, the converter converts to a lower code for a higher input voltage. Missing codes are those values which are never converted for any input value. In 8-bit or 10-bit mode, the ADC is guaranteed to be monotonic and to have no missing codes. MC9S08AW60 Data Sheet, Rev.1.0 256 Freescale Semiconductor Chapter 15 Development Support 15.1 Introduction This chapter describes the single-wire background debug mode (BDM), which uses the on-chip background debug controller (BDC) module, and the independent on-chip real-time in-circuit emulation (ICE) system, which uses the on-chip debug (DBG) module. 15.1.1 Features Features of the BDC module include: • Single pin for mode selection and background communications • BDC registers are not located in the memory map • SYNC command to determine target communications rate • Non-intrusive commands for memory access • Active background mode commands for CPU register access • GO and TRACE1 commands • BACKGROUND command can wake CPU from stop or wait modes • One hardware address breakpoint built into BDC • Oscillator runs in stop mode, if BDC enabled • COP watchdog disabled while in active background mode Features of the ICE system include: • Two trigger comparators: Two address + read/write (R/W) or one full address + data + R/W • Flexible 8-word by 16-bit FIFO (first-in, first-out) buffer for capture information: — Change-of-flow addresses or — Event-only data • Two types of breakpoints: — Tag breakpoints for instruction opcodes — Force breakpoints for any address access • Nine trigger modes: — Basic: A-only, A OR B — Sequence: A then B — Full: A AND B data, A AND NOT B data — Event (store data): Event-only B, A then event-only B — Range: Inside range (A ≤ address ≤ B), outside range (address < A or address > B) MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 257 Chapter 15 Development Support 15.2 Background Debug Controller (BDC) All MCUs in the HCS08 Family contain a single-wire background debug interface that supports in-circuit programming of on-chip nonvolatile memory and sophisticated non-intrusive debug capabilities. Unlike debug interfaces on earlier 8-bit MCUs, this system does not interfere with normal application resources. It does not use any user memory or locations in the memory map and does not share any on-chip peripherals. BDC commands are divided into two groups: • Active background mode commands require that the target MCU is in active background mode (the user program is not running). Active background mode commands allow the CPU registers to be read or written, and allow the user to trace one user instruction at a time, or GO to the user program from active background mode. • Non-intrusive commands can be executed at any time even while the user’s program is running. Non-intrusive commands allow a user to read or write MCU memory locations or access status and control registers within the background debug controller. Typically, a relatively simple interface pod is used to translate commands from a host computer into commands for the custom serial interface to the single-wire background debug system. Depending on the development tool vendor, this interface pod may use a standard RS-232 serial port, a parallel printer port, or some other type of communications such as a universal serial bus (USB) to communicate between the host PC and the pod. The pod typically connects to the target system with ground, the BKGD pin, RESET, and sometimes VDD. An open-drain connection to reset allows the host to force a target system reset, which is useful to regain control of a lost target system or to control startup of a target system before the on-chip nonvolatile memory has been programmed. Sometimes VDD can be used to allow the pod to use power from the target system to avoid the need for a separate power supply. However, if the pod is powered separately, it can be connected to a running target system without forcing a target system reset or otherwise disturbing the running application program. BKGD 1 2 GND NO CONNECT 3 4 RESET NO CONNECT 5 6 VDD Figure 15-1. BDM Tool Connector 15.2.1 BKGD Pin Description BKGD is the single-wire background debug interface pin. The primary function of this pin is for bidirectional serial communication of active background mode commands and data. During reset, this pin is used to select between starting in active background mode or starting the user’s application program. This pin is also used to request a timed sync response pulse to allow a host development tool to determine the correct clock frequency for background debug serial communications. BDC serial communications use a custom serial protocol first introduced on the M68HC12 Family of microcontrollers. This protocol assumes the host knows the communication clock rate that is determined by the target BDC clock rate. All communication is initiated and controlled by the host that drives a high-to-low edge to signal the beginning of each bit time. Commands and data are sent most significant bit MC9S08AW60 Data Sheet, Rev.1.0 258 Freescale Semiconductor Chapter 15 Development Support first (MSB first). For a detailed description of the communications protocol, refer to Section 15.2.2, “Communication Details.” If a host is attempting to communicate with a target MCU that has an unknown BDC clock rate, a SYNC command may be sent to the target MCU to request a timed sync response signal from which the host can determine the correct communication speed. BKGD is a pseudo-open-drain pin and there is an on-chip pullup so no external pullup resistor is required. Unlike typical open-drain pins, the external RC time constant on this pin, which is influenced by external capacitance, plays almost no role in signal rise time. The custom protocol provides for brief, actively driven speedup pulses to force rapid rise times on this pin without risking harmful drive level conflicts. Refer to Section 15.2.2, “Communication Details,” for more detail. When no debugger pod is connected to the 6-pin BDM interface connector, the internal pullup on BKGD chooses normal operating mode. When a development system is connected, it can pull both BKGD and RESET low, release RESET to select active background mode rather than normal operating mode, then release BKGD. It is not necessary to reset the target MCU to communicate with it through the background debug interface. 15.2.2 Communication Details The BDC serial interface requires the external controller to generate a falling edge on the BKGD pin to indicate the start of each bit time. The external controller provides this falling edge whether data is transmitted or received. BKGD is a pseudo-open-drain pin that can be driven either by an external controller or by the MCU. Data is transferred MSB first at 16 BDC clock cycles per bit (nominal speed). The interface times out if 512 BDC clock cycles occur between falling edges from the host. Any BDC command that was in progress when this timeout occurs is aborted without affecting the memory or operating mode of the target MCU system. The custom serial protocol requires the debug pod to know the target BDC communication clock speed. The clock switch (CLKSW) control bit in the BDC status and control register allows the user to select the BDC clock source. The BDC clock source can either be the bus or the alternate BDC clock source. The BKGD pin can receive a high or low level or transmit a high or low level. The following diagrams show timing for each of these cases. Interface timing is synchronous to clocks in the target BDC, but asynchronous to the external host. The internal BDC clock signal is shown for reference in counting cycles. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 259 Chapter 15 Development Support Figure 15-2 shows an external host transmitting a logic 1 or 0 to the BKGD pin of a target HCS08 MCU. The host is asynchronous to the target so there is a 0-to-1 cycle delay from the host-generated falling edge to where the target perceives the beginning of the bit time. Ten target BDC clock cycles later, the target senses the bit level on the BKGD pin. Typically, the host actively drives the pseudo-open-drain BKGD pin during host-to-target transmissions to speed up rising edges. Because the target does not drive the BKGD pin during the host-to-target transmission period, there is no need to treat the line as an open-drain signal during this period. BDC CLOCK (TARGET MCU) HOST TRANSMIT 1 HOST TRANSMIT 0 10 CYCLES SYNCHRONIZATION UNCERTAINTY EARLIEST START OF NEXT BIT TARGET SENSES BIT LEVEL PERCEIVED START OF BIT TIME Figure 15-2. BDC Host-to-Target Serial Bit Timing MC9S08AW60 Data Sheet, Rev.1.0 260 Freescale Semiconductor Chapter 15 Development Support Figure 15-3 shows the host receiving a logic 1 from the target HCS08 MCU. Because the host is asynchronous to the target MCU, there is a 0-to-1 cycle delay from the host-generated falling edge on BKGD to the perceived start of the bit time in the target MCU. The host holds the BKGD pin low long enough for the target to recognize it (at least two target BDC cycles). The host must release the low drive before the target MCU drives a brief active-high speedup pulse seven cycles after the perceived start of the bit time. The host should sample the bit level about 10 cycles after it started the bit time. BDC CLOCK (TARGET MCU) HOST DRIVE TO BKGD PIN HIGH-IMPEDANCE TARGET MCU SPEEDUP PULSE HIGH-IMPEDANCE HIGH-IMPEDANCE PERCEIVED START OF BIT TIME R-C RISE BKGD PIN 10 CYCLES 10 CYCLES EARLIEST START OF NEXT BIT HOST SAMPLES BKGD PIN Figure 15-3. BDC Target-to-Host Serial Bit Timing (Logic 1) MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 261 Chapter 15 Development Support Figure 15-4 shows the host receiving a logic 0 from the target HCS08 MCU. Because the host is asynchronous to the target MCU, there is a 0-to-1 cycle delay from the host-generated falling edge on BKGD to the start of the bit time as perceived by the target MCU. The host initiates the bit time but the target HCS08 finishes it. Because the target wants the host to receive a logic 0, it drives the BKGD pin low for 13 BDC clock cycles, then briefly drives it high to speed up the rising edge. The host samples the bit level about 10 cycles after starting the bit time. BDC CLOCK (TARGET MCU) HOST DRIVE TO BKGD PIN HIGH-IMPEDANCE SPEEDUP PULSE TARGET MCU DRIVE AND SPEED-UP PULSE PERCEIVED START OF BIT TIME BKGD PIN 10 CYCLES 10 CYCLES EARLIEST START OF NEXT BIT HOST SAMPLES BKGD PIN Figure 15-4. BDM Target-to-Host Serial Bit Timing (Logic 0) MC9S08AW60 Data Sheet, Rev.1.0 262 Freescale Semiconductor Chapter 15 Development Support 15.2.3 BDC Commands BDC commands are sent serially from a host computer to the BKGD pin of the target HCS08 MCU. All commands and data are sent MSB-first using a custom BDC communications protocol. Active background mode commands require that the target MCU is currently in the active background mode while non-intrusive commands may be issued at any time whether the target MCU is in active background mode or running a user application program. Table 15-1 shows all HCS08 BDC commands, a shorthand description of their coding structure, and the meaning of each command. Coding Structure Nomenclature This nomenclature is used in Table 15-1 to describe the coding structure of the BDC commands. Commands begin with an 8-bit hexadecimal command code in the host-to-target direction (most significant bit first) / = separates parts of the command d = delay 16 target BDC clock cycles AAAA = a 16-bit address in the host-to-target direction RD = 8 bits of read data in the target-to-host direction WD = 8 bits of write data in the host-to-target direction RD16 = 16 bits of read data in the target-to-host direction WD16 = 16 bits of write data in the host-to-target direction SS = the contents of BDCSCR in the target-to-host direction (STATUS) CC = 8 bits of write data for BDCSCR in the host-to-target direction (CONTROL) RBKP = 16 bits of read data in the target-to-host direction (from BDCBKPT breakpoint register) WBKP = 16 bits of write data in the host-to-target direction (for BDCBKPT breakpoint register) MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 263 Chapter 15 Development Support Table 15-1. BDC Command Summary Command Mnemonic 1 Active BDM/ Non-intrusive Coding Structure Description SYNC Non-intrusive n/a1 Request a timed reference pulse to determine target BDC communication speed ACK_ENABLE Non-intrusive D5/d Enable acknowledge protocol. Refer to Freescale document order no. HCS08RMv1/D. ACK_DISABLE Non-intrusive D6/d Disable acknowledge protocol. Refer to Freescale document order no. HCS08RMv1/D. BACKGROUND Non-intrusive 90/d Enter active background mode if enabled (ignore if ENBDM bit equals 0) READ_STATUS Non-intrusive E4/SS Read BDC status from BDCSCR WRITE_CONTROL Non-intrusive C4/CC Write BDC controls in BDCSCR READ_BYTE Non-intrusive E0/AAAA/d/RD Read a byte from target memory READ_BYTE_WS Non-intrusive E1/AAAA/d/SS/RD Read a byte and report status READ_LAST Non-intrusive E8/SS/RD Re-read byte from address just read and report status WRITE_BYTE Non-intrusive C0/AAAA/WD/d Write a byte to target memory WRITE_BYTE_WS Non-intrusive C1/AAAA/WD/d/SS Write a byte and report status READ_BKPT Non-intrusive E2/RBKP Read BDCBKPT breakpoint register WRITE_BKPT Non-intrusive C2/WBKP Write BDCBKPT breakpoint register GO Active BDM 08/d Go to execute the user application program starting at the address currently in the PC TRACE1 Active BDM 10/d Trace 1 user instruction at the address in the PC, then return to active background mode TAGGO Active BDM 18/d Same as GO but enable external tagging (HCS08 devices have no external tagging pin) READ_A Active BDM 68/d/RD Read accumulator (A) READ_CCR Active BDM 69/d/RD Read condition code register (CCR) READ_PC Active BDM 6B/d/RD16 Read program counter (PC) READ_HX Active BDM 6C/d/RD16 Read H and X register pair (H:X) READ_SP Active BDM 6F/d/RD16 Read stack pointer (SP) READ_NEXT Active BDM 70/d/RD Increment H:X by one then read memory byte located at H:X READ_NEXT_WS Active BDM 71/d/SS/RD Increment H:X by one then read memory byte located at H:X. Report status and data. WRITE_A Active BDM 48/WD/d Write accumulator (A) WRITE_CCR Active BDM 49/WD/d Write condition code register (CCR) WRITE_PC Active BDM 4B/WD16/d Write program counter (PC) WRITE_HX Active BDM 4C/WD16/d Write H and X register pair (H:X) WRITE_SP Active BDM 4F/WD16/d Write stack pointer (SP) WRITE_NEXT Active BDM 50/WD/d Increment H:X by one, then write memory byte located at H:X WRITE_NEXT_WS Active BDM 51/WD/d/SS Increment H:X by one, then write memory byte located at H:X. Also report status. The SYNC command is a special operation that does not have a command code. MC9S08AW60 Data Sheet, Rev.1.0 264 Freescale Semiconductor Chapter 15 Development Support The SYNC command is unlike other BDC commands because the host does not necessarily know the correct communications speed to use for BDC communications until after it has analyzed the response to the SYNC command. To issue a SYNC command, the host: • Drives the BKGD pin low for at least 128 cycles of the slowest possible BDC clock (The slowest clock is normally the reference oscillator/64 or the self-clocked rate/64.) • Drives BKGD high for a brief speedup pulse to get a fast rise time (This speedup pulse is typically one cycle of the fastest clock in the system.) • Removes all drive to the BKGD pin so it reverts to high impedance • Monitors the BKGD pin for the sync response pulse The target, upon detecting the SYNC request from the host (which is a much longer low time than would ever occur during normal BDC communications): • Waits for BKGD to return to a logic high • Delays 16 cycles to allow the host to stop driving the high speedup pulse • Drives BKGD low for 128 BDC clock cycles • Drives a 1-cycle high speedup pulse to force a fast rise time on BKGD • 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 BDC communications. Typically, the host can determine the correct communication speed within a few percent of the actual target speed and the communication protocol can easily tolerate speed errors of several percent. 15.2.4 BDC Hardware Breakpoint The BDC includes one relatively simple hardware breakpoint that compares the CPU address bus to a 16-bit match value in the BDCBKPT register. This breakpoint can generate a forced breakpoint or a tagged breakpoint. A forced breakpoint causes the CPU to enter active background mode at the first instruction boundary following any access to the breakpoint address. The tagged breakpoint causes the instruction opcode at the breakpoint address to be tagged so that the CPU will enter active background mode rather than executing that instruction if and when it reaches the end of the instruction queue. This implies that tagged breakpoints can only be placed at the address of an instruction opcode while forced breakpoints can be set at any address. The breakpoint enable (BKPTEN) control bit in the BDC status and control register (BDCSCR) is used to enable the breakpoint logic (BKPTEN = 1). When BKPTEN = 0, its default value after reset, the breakpoint logic is disabled and no BDC breakpoints are requested regardless of the values in other BDC breakpoint registers and control bits. The force/tag select (FTS) control bit in BDCSCR is used to select forced (FTS = 1) or tagged (FTS = 0) type breakpoints. The on-chip debug module (DBG) includes circuitry for two additional hardware breakpoints that are more flexible than the simple breakpoint in the BDC module. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 265 Chapter 15 Development Support 15.3 On-Chip Debug System (DBG) Because HCS08 devices do not have external address and data buses, the most important functions of an in-circuit emulator have been built onto the chip with the MCU. The debug system consists of an 8-stage FIFO that can store address or data bus information, and a flexible trigger system to decide when to capture bus information and what information to capture. The system relies on the single-wire background debug system to access debug control registers and to read results out of the eight stage FIFO. The debug module includes control and status registers that are accessible in the user’s memory map. These registers are located in the high register space to avoid using valuable direct page memory space. Most of the debug module’s functions are used during development, and user programs rarely access any of the control and status registers for the debug module. The one exception is that the debug system can provide the means to implement a form of ROM patching. This topic is discussed in greater detail in Section 15.3.6, “Hardware Breakpoints.” 15.3.1 Comparators A and B Two 16-bit comparators (A and B) can optionally be qualified with the R/W signal and an opcode tracking circuit. Separate control bits allow you to ignore R/W for each comparator. The opcode tracking circuitry optionally allows you to specify that a trigger will occur only if the opcode at the specified address is actually executed as opposed to only being read from memory into the instruction queue. The comparators are also capable of magnitude comparisons to support the inside range and outside range trigger modes. Comparators are disabled temporarily during all BDC accesses. The A comparator is always associated with the 16-bit CPU address. The B comparator compares to the CPU address or the 8-bit CPU data bus, depending on the trigger mode selected. Because the CPU data bus is separated into a read data bus and a write data bus, the RWAEN and RWA control bits have an additional purpose, in full address plus data comparisons they are used to decide which of these buses to use in the comparator B data bus comparisons. If RWAEN = 1 (enabled) and RWA = 0 (write), the CPU’s write data bus is used. Otherwise, the CPU’s read data bus is used. The currently selected trigger mode determines what the debugger logic does when a comparator detects a qualified match condition. A match can cause: • Generation of a breakpoint to the CPU • Storage of data bus values into the FIFO • Starting to store change-of-flow addresses into the FIFO (begin type trace) • Stopping the storage of change-of-flow addresses into the FIFO (end type trace) 15.3.2 Bus Capture Information and FIFO Operation The usual way to use the FIFO is to setup the trigger mode and other control options, then arm the debugger. When the FIFO has filled or the debugger has stopped storing data into the FIFO, you would read the information out of it in the order it was stored into the FIFO. Status bits indicate the number of words of valid information that are in the FIFO as data is stored into it. If a trace run is manually halted by writing 0 to ARM before the FIFO is full (CNT = 1:0:0:0), the information is shifted by one position and MC9S08AW60 Data Sheet, Rev.1.0 266 Freescale Semiconductor Chapter 15 Development Support the host must perform ((8 – CNT) – 1) dummy reads of the FIFO to advance it to the first significant entry in the FIFO. In most trigger modes, the information stored in the FIFO consists of 16-bit change-of-flow addresses. In these cases, read DBGFH then DBGFL to get one coherent word of information out of the FIFO. Reading DBGFL (the low-order byte of the FIFO data port) causes the FIFO to shift so the next word of information is available at the FIFO data port. In the event-only trigger modes (see Section 15.3.5, “Trigger Modes”), 8-bit data information is stored into the FIFO. In these cases, the high-order half of the FIFO (DBGFH) is not used and data is read out of the FIFO by simply reading DBGFL. Each time DBGFL is read, the FIFO is shifted so the next data value is available through the FIFO data port at DBGFL. In trigger modes where the FIFO is storing change-of-flow addresses, there is a delay between CPU addresses and the input side of the FIFO. Because of this delay, if the trigger event itself is a change-of-flow address or a change-of-flow address appears during the next two bus cycles after a trigger event starts the FIFO, it will not be saved into the FIFO. In the case of an end-trace, if the trigger event is a change-of-flow, it will be saved as the last change-of-flow entry for that debug run. The FIFO can also be used to generate a profile of executed instruction addresses when the debugger is not armed. When ARM = 0, reading DBGFL causes the address of the most-recently fetched opcode to be saved in the FIFO. To use the profiling feature, a host debugger would read addresses out of the FIFO by reading DBGFH then DBGFL at regular periodic intervals. The first eight values would be discarded because they correspond to the eight DBGFL reads needed to initially fill the FIFO. Additional periodic reads of DBGFH and DBGFL return delayed information about executed instructions so the host debugger can develop a profile of executed instruction addresses. 15.3.3 Change-of-Flow Information To minimize the amount of information stored in the FIFO, only information related to instructions that cause a change to the normal sequential execution of instructions is stored. With knowledge of the source and object code program stored in the target system, an external debugger system can reconstruct the path of execution through many instructions from the change-of-flow information stored in the FIFO. For conditional branch instructions where the branch is taken (branch condition was true), the source address is stored (the address of the conditional branch opcode). Because BRA and BRN instructions are not conditional, these events do not cause change-of-flow information to be stored in the FIFO. Indirect JMP and JSR instructions use the current contents of the H:X index register pair to determine the destination address, so the debug system stores the run-time destination address for any indirect JMP or JSR. For interrupts, RTI, or RTS, the destination address is stored in the FIFO as change-of-flow information. 15.3.4 Tag vs. Force Breakpoints and Triggers Tagging is a term that refers to identifying an instruction opcode as it is fetched into the instruction queue, but not taking any other action until and unless that instruction is actually executed by the CPU. This distinction is important because any change-of-flow from a jump, branch, subroutine call, or interrupt causes some instructions that have been fetched into the instruction queue to be thrown away without being executed. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 267 Chapter 15 Development Support A force-type breakpoint waits for the current instruction to finish and then acts upon the breakpoint request. The usual action in response to a breakpoint is to go to active background mode rather than continuing to the next instruction in the user application program. The tag vs. force terminology is used in two contexts within the debug module. The first context refers to breakpoint requests from the debug module to the CPU. The second refers to match signals from the comparators to the debugger control logic. When a tag-type break request is sent to the CPU, a signal is entered into the instruction queue along with the opcode so that if/when this opcode ever executes, the CPU will effectively replace the tagged opcode with a BGND opcode so the CPU goes to active background mode rather than executing the tagged instruction. When the TRGSEL control bit in the DBGT register is set to select tag-type operation, the output from comparator A or B is qualified by a block of logic in the debug module that tracks opcodes and only produces a trigger to the debugger if the opcode at the compare address is actually executed. There is separate opcode tracking logic for each comparator so more than one compare event can be tracked through the instruction queue at a time. 15.3.5 Trigger Modes The trigger mode controls the overall behavior of a debug run. The 4-bit TRG field in the DBGT register selects one of nine trigger modes. When TRGSEL = 1 in the DBGT register, the output of the comparator must propagate through an opcode tracking circuit before triggering FIFO actions. The BEGIN bit in DBGT chooses whether the FIFO begins storing data when the qualified trigger is detected (begin trace), or the FIFO stores data in a circular fashion from the time it is armed until the qualified trigger is detected (end trigger). A debug run is started by writing a 1 to the ARM bit in the DBGC register, which sets the ARMF flag and clears the AF and BF flags and the CNT bits in DBGS. A begin-trace debug run ends when the FIFO gets full. An end-trace run ends when the selected trigger event occurs. Any debug run can be stopped manually by writing a 0 to ARM or DBGEN in DBGC. In all trigger modes except event-only modes, the FIFO stores change-of-flow addresses. In event-only trigger modes, the FIFO stores data in the low-order eight bits of the FIFO. The BEGIN control bit is ignored in event-only trigger modes and all such debug runs are begin type traces. When TRGSEL = 1 to select opcode fetch triggers, it is not necessary to use R/W in comparisons because opcode tags would only apply to opcode fetches that are always read cycles. It would also be unusual to specify TRGSEL = 1 while using a full mode trigger because the opcode value is normally known at a particular address. The following trigger mode descriptions only state the primary comparator conditions that lead to a trigger. Either comparator can usually be further qualified with R/W by setting RWAEN (RWBEN) and the corresponding RWA (RWB) value to be matched against R/W. The signal from the comparator with optional R/W qualification is used to request a CPU breakpoint if BRKEN = 1 and TAG determines whether the CPU request will be a tag request or a force request. MC9S08AW60 Data Sheet, Rev.1.0 268 Freescale Semiconductor Chapter 15 Development Support A-Only — Trigger when the address matches the value in comparator A A OR B — Trigger when the address matches either the value in comparator A or the value in comparator B A Then B — Trigger when the address matches the value in comparator B but only after the address for another cycle matched the value in comparator A. There can be any number of cycles after the A match and before the B match. A AND B Data (Full Mode) — This is called a full mode because address, data, and R/W (optionally) must match within the same bus cycle to cause a trigger event. Comparator A checks address, the low byte of comparator B checks data, and R/W is checked against RWA if RWAEN = 1. The high-order half of comparator B is not used. In full trigger modes it is not useful to specify a tag-type CPU breakpoint (BRKEN = TAG = 1), but if you do, the comparator B data match is ignored for the purpose of issuing the tag request to the CPU and the CPU breakpoint is issued when the comparator A address matches. A AND NOT B Data (Full Mode) — Address must match comparator A, data must not match the low half of comparator B, and R/W must match RWA if RWAEN = 1. All three conditions must be met within the same bus cycle to cause a trigger. In full trigger modes it is not useful to specify a tag-type CPU breakpoint (BRKEN = TAG = 1), but if you do, the comparator B data match is ignored for the purpose of issuing the tag request to the CPU and the CPU breakpoint is issued when the comparator A address matches. Event-Only B (Store Data) — Trigger events occur each time the address matches the value in comparator B. Trigger events cause the data to be captured into the FIFO. The debug run ends when the FIFO becomes full. A Then Event-Only B (Store Data) — After the address has matched the value in comparator A, a trigger event occurs each time the address matches the value in comparator B. Trigger events cause the data to be captured into the FIFO. The debug run ends when the FIFO becomes full. Inside Range (A ≤ Address ≤ B) — A trigger occurs when the address is greater than or equal to the value in comparator A and less than or equal to the value in comparator B at the same time. Outside Range (Address < A or Address > B) — A trigger occurs when the address is either less than the value in comparator A or greater than the value in comparator B. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 269 Chapter 15 Development Support 15.3.6 Hardware Breakpoints The BRKEN control bit in the DBGC register may be set to 1 to allow any of the trigger conditions described in Section 15.3.5, “Trigger Modes,” to be used to generate a hardware breakpoint request to the CPU. TAG in DBGC controls whether the breakpoint request will be treated as a tag-type breakpoint or a force-type breakpoint. A tag breakpoint causes the current opcode to be marked as it enters the instruction queue. If a tagged opcode reaches the end of the pipe, the CPU executes a BGND instruction to go to active background mode rather than executing the tagged opcode. A force-type breakpoint causes the CPU to finish the current instruction and then go to active background mode. If the background mode has not been enabled (ENBDM = 1) by a serial WRITE_CONTROL command through the BKGD pin, the CPU will execute an SWI instruction instead of going to active background mode. 15.4 Register Definition This section contains the descriptions of the BDC and DBG registers and control bits. Refer to the high-page register summary in the device overview chapter of this data sheet for the absolute address assignments for all DBG registers. This section refers to registers and control bits only by their names. A Freescale-provided equate or header file is used to translate these names into the appropriate absolute addresses. 15.4.1 BDC Registers and Control Bits The BDC has two registers: • The BDC status and control register (BDCSCR) is an 8-bit register containing control and status bits for the background debug controller. • The BDC breakpoint match register (BDCBKPT) holds a 16-bit breakpoint match address. These registers are accessed with dedicated serial BDC commands and are not located in the memory space of the target MCU (so they do not have addresses and cannot be accessed by user programs). Some of the bits in the BDCSCR have write limitations; otherwise, these registers may be read or written at any time. For example, the ENBDM control bit may not be written while the MCU is in active background mode. (This prevents the ambiguous condition of the control bit forbidding active background mode while the MCU is already in active background mode.) Also, the four status bits (BDMACT, WS, WSF, and DVF) are read-only status indicators and can never be written by the WRITE_CONTROL serial BDC command. The clock switch (CLKSW) control bit may be read or written at any time. MC9S08AW60 Data Sheet, Rev.1.0 270 Freescale Semiconductor Chapter 15 Development Support 15.4.1.1 BDC Status and Control Register (BDCSCR) This register can be read or written by serial BDC commands (READ_STATUS and WRITE_CONTROL) but is not accessible to user programs because it is not located in the normal memory map of the MCU. 7 6 R 5 4 3 BKPTEN FTS CLKSW BDMACT ENBDM 2 1 0 WS WSF DVF W Normal Reset 0 0 0 0 0 0 0 0 Reset in Active BDM: 1 1 0 0 1 0 0 0 = Unimplemented or Reserved Figure 15-5. BDC Status and Control Register (BDCSCR) Table 15-2. BDCSCR Register Field Descriptions Field Description 7 ENBDM Enable BDM (Permit Active Background Mode) — Typically, this bit is written to 1 by the debug host shortly after the beginning of a debug session or whenever the debug host resets the target and remains 1 until a normal reset clears it. 0 BDM cannot be made active (non-intrusive commands still allowed) 1 BDM can be made active to allow active background mode commands 6 BDMACT Background Mode Active Status — This is a read-only status bit. 0 BDM not active (user application program running) 1 BDM active and waiting for serial commands 5 BKPTEN BDC Breakpoint Enable — If this bit is clear, the BDC breakpoint is disabled and the FTS (force tag select) control bit and BDCBKPT match register are ignored. 0 BDC breakpoint disabled 1 BDC breakpoint enabled 4 FTS 3 CLKSW Force/Tag Select — When FTS = 1, a breakpoint is requested whenever the CPU address bus matches the BDCBKPT match register. When FTS = 0, a match between the CPU address bus and the BDCBKPT register causes the fetched opcode to be tagged. If this tagged opcode ever reaches the end of the instruction queue, the CPU enters active background mode rather than executing the tagged opcode. 0 Tag opcode at breakpoint address and enter active background mode if CPU attempts to execute that instruction 1 Breakpoint match forces active background mode at next instruction boundary (address need not be an opcode) Select Source for BDC Communications Clock — CLKSW defaults to 0, which selects the alternate BDC clock source. 0 Alternate BDC clock source 1 MCU bus clock MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 271 Chapter 15 Development Support Table 15-2. BDCSCR Register Field Descriptions (continued) Field Description 2 WS Wait or Stop Status — When the target CPU is in wait or stop mode, most BDC commands cannot function. However, the BACKGROUND command can be used to force the target CPU out of wait or stop and into active background mode where all BDC commands work. Whenever the host forces the target MCU into active background mode, the host should issue a READ_STATUS command to check that BDMACT = 1 before attempting other BDC commands. 0 Target CPU is running user application code or in active background mode (was not in wait or stop mode when background became active) 1 Target CPU is in wait or stop mode, or a BACKGROUND command was used to change from wait or stop to active background mode 1 WSF Wait or Stop Failure Status — This status bit is set if a memory access command failed due to the target CPU executing a wait or stop instruction at or about the same time. The usual recovery strategy is to issue a BACKGROUND command to get out of wait or stop mode into active background mode, repeat the command that failed, then return to the user program. (Typically, the host would restore CPU registers and stack values and re-execute the wait or stop instruction.) 0 Memory access did not conflict with a wait or stop instruction 1 Memory access command failed because the CPU entered wait or stop mode 0 DVF Data Valid Failure Status — This status bit is not used in the MC9S08AW60/48/32/16 because it does not have any slow access memory. 0 Memory access did not conflict with a slow memory access 1 Memory access command failed because CPU was not finished with a slow memory access 15.4.1.2 BDC Breakpoint Match Register (BDCBKPT) This 16-bit register holds the address for the hardware breakpoint in the BDC. The BKPTEN and FTS control bits in BDCSCR are used to enable and configure the breakpoint logic. Dedicated serial BDC commands (READ_BKPT and WRITE_BKPT) are used to read and write the BDCBKPT register but is not accessible to user programs because it is not located in the normal memory map of the MCU. Breakpoints are normally set while the target MCU is in active background mode before running the user application program. For additional information about setup and use of the hardware breakpoint logic in the BDC, refer to Section 15.2.4, “BDC Hardware Breakpoint.” 15.4.2 System Background Debug Force Reset Register (SBDFR) This register contains a single write-only control bit. A serial background mode command such as WRITE_BYTE must be used to write to SBDFR. Attempts to write this register from a user program are ignored. Reads always return 0x00. MC9S08AW60 Data Sheet, Rev.1.0 272 Freescale Semiconductor Chapter 15 Development Support R 7 6 5 4 3 2 1 0 0 0 0 0 0 0 0 0 BDFR1 W Reset 0 0 0 0 0 0 0 0 = Unimplemented or Reserved 1 BDFR is writable only through serial background mode debug commands, not from user programs. Figure 15-6. System Background Debug Force Reset Register (SBDFR) Table 15-3. SBDFR Register Field Description Field Description 0 BDFR Background Debug Force Reset — A serial active background mode command such as WRITE_BYTE allows an external debug host to force a target system reset. Writing 1 to this bit forces an MCU reset. This bit cannot be written from a user program. 15.4.3 DBG Registers and Control Bits The debug module includes nine bytes of register space for three 16-bit registers and three 8-bit control and status registers. These registers are located in the high register space of the normal memory map so they are accessible to normal application programs. These registers are rarely if ever accessed by normal user application programs with the possible exception of a ROM patching mechanism that uses the breakpoint logic. 15.4.3.1 Debug Comparator A High Register (DBGCAH) This register contains compare value bits for the high-order eight bits of comparator A. This register is forced to 0x00 at reset and can be read at any time or written at any time unless ARM = 1. 15.4.3.2 Debug Comparator A Low Register (DBGCAL) This register contains compare value bits for the low-order eight bits of comparator A. This register is forced to 0x00 at reset and can be read at any time or written at any time unless ARM = 1. 15.4.3.3 Debug Comparator B High Register (DBGCBH) This register contains compare value bits for the high-order eight bits of comparator B. This register is forced to 0x00 at reset and can be read at any time or written at any time unless ARM = 1. 15.4.3.4 Debug Comparator B Low Register (DBGCBL) This register contains compare value bits for the low-order eight bits of comparator B. This register is forced to 0x00 at reset and can be read at any time or written at any time unless ARM = 1. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 273 Chapter 15 Development Support 15.4.3.5 Debug FIFO High Register (DBGFH) This register provides read-only access to the high-order eight bits of the FIFO. Writes to this register have no meaning or effect. In the event-only trigger modes, the FIFO only stores data into the low-order byte of each FIFO word, so this register is not used and will read 0x00. Reading DBGFH does not cause the FIFO to shift to the next word. When reading 16-bit words out of the FIFO, read DBGFH before reading DBGFL because reading DBGFL causes the FIFO to advance to the next word of information. 15.4.3.6 Debug FIFO Low Register (DBGFL) This register provides read-only access to the low-order eight bits of the FIFO. Writes to this register have no meaning or effect. Reading DBGFL causes the FIFO to shift to the next available word of information. When the debug module is operating in event-only modes, only 8-bit data is stored into the FIFO (high-order half of each FIFO word is unused). When reading 8-bit words out of the FIFO, simply read DBGFL repeatedly to get successive bytes of data from the FIFO. It isn’t necessary to read DBGFH in this case. Do not attempt to read data from the FIFO while it is still armed (after arming but before the FIFO is filled or ARMF is cleared) because the FIFO is prevented from advancing during reads of DBGFL. This can interfere with normal sequencing of reads from the FIFO. Reading DBGFL while the debugger is not armed causes the address of the most-recently fetched opcode to be stored to the last location in the FIFO. By reading DBGFH then DBGFL periodically, external host software can develop a profile of program execution. After eight reads from the FIFO, the ninth read will return the information that was stored as a result of the first read. To use the profiling feature, read the FIFO eight times without using the data to prime the sequence and then begin using the data to get a delayed picture of what addresses were being executed. The information stored into the FIFO on reads of DBGFL (while the FIFO is not armed) is the address of the most-recently fetched opcode. MC9S08AW60 Data Sheet, Rev.1.0 274 Freescale Semiconductor Chapter 15 Development Support 15.4.3.7 Debug Control Register (DBGC) This register can be read or written at any time. 7 6 5 4 3 2 1 0 DBGEN ARM TAG BRKEN RWA RWAEN RWB RWBEN 0 0 0 0 0 0 0 0 R W Reset Figure 15-7. Debug Control Register (DBGC) Table 15-4. DBGC Register Field Descriptions Field Description 7 DBGEN Debug Module Enable — Used to enable the debug module. DBGEN cannot be set to 1 if the MCU is secure. 0 DBG disabled 1 DBG enabled 6 ARM Arm Control — Controls whether the debugger is comparing and storing information in the FIFO. A write is used to set this bit (and ARMF) and completion of a debug run automatically clears it. Any debug run can be manually stopped by writing 0 to ARM or to DBGEN. 0 Debugger not armed 1 Debugger armed 5 TAG Tag/Force Select — Controls whether break requests to the CPU will be tag or force type requests. If BRKEN = 0, this bit has no meaning or effect. 0 CPU breaks requested as force type requests 1 CPU breaks requested as tag type requests 4 BRKEN Break Enable — Controls whether a trigger event will generate a break request to the CPU. Trigger events can cause information to be stored in the FIFO without generating a break request to the CPU. For an end trace, CPU break requests are issued to the CPU when the comparator(s) and R/W meet the trigger requirements. For a begin trace, CPU break requests are issued when the FIFO becomes full. TRGSEL does not affect the timing of CPU break requests. 0 CPU break requests not enabled 1 Triggers cause a break request to the CPU 3 RWA R/W Comparison Value for Comparator A — When RWAEN = 1, this bit determines whether a read or a write access qualifies comparator A. When RWAEN = 0, RWA and the R/W signal do not affect comparator A. 0 Comparator A can only match on a write cycle 1 Comparator A can only match on a read cycle 2 RWAEN Enable R/W for Comparator A — Controls whether the level of R/W is considered for a comparator A match. 0 R/W is not used in comparison A 1 R/W is used in comparison A 1 RWB R/W Comparison Value for Comparator B — When RWBEN = 1, this bit determines whether a read or a write access qualifies comparator B. When RWBEN = 0, RWB and the R/W signal do not affect comparator B. 0 Comparator B can match only on a write cycle 1 Comparator B can match only on a read cycle 0 RWBEN Enable R/W for Comparator B — Controls whether the level of R/W is considered for a comparator B match. 0 R/W is not used in comparison B 1 R/W is used in comparison B MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 275 Chapter 15 Development Support 15.4.3.8 Debug Trigger Register (DBGT) This register can be read any time, but may be written only if ARM = 0, except bits 4 and 5 are hard-wired to 0s. 7 6 TRGSEL BEGIN 0 0 R 5 4 0 0 3 2 1 0 TRG3 TRG2 TRG1 TRG0 0 0 0 0 W Reset 0 0 = Unimplemented or Reserved Figure 15-8. Debug Trigger Register (DBGT) Table 15-5. DBGT Register Field Descriptions Field Description 7 TRGSEL Trigger Type — Controls whether the match outputs from comparators A and B are qualified with the opcode tracking logic in the debug module. If TRGSEL is set, a match signal from comparator A or B must propagate through the opcode tracking logic and a trigger event is only signalled to the FIFO logic if the opcode at the match address is actually executed. 0 Trigger on access to compare address (force) 1 Trigger if opcode at compare address is executed (tag) 6 BEGIN Begin/End Trigger Select — Controls whether the FIFO starts filling at a trigger or fills in a circular manner until a trigger ends the capture of information. In event-only trigger modes, this bit is ignored and all debug runs are assumed to be begin traces. 0 Data stored in FIFO until trigger (end trace) 1 Trigger initiates data storage (begin trace) 3:0 TRG[3:0] Select Trigger Mode — Selects one of nine triggering modes, as described below. 0000 A-only 0001 A OR B 0010 A Then B 0011 Event-only B (store data) 0100 A then event-only B (store data) 0101 A AND B data (full mode) 0110 A AND NOT B data (full mode) 0111 Inside range: A ≤ address ≤ B 1000 Outside range: address < A or address > B 1001 – 1111 (No trigger) MC9S08AW60 Data Sheet, Rev.1.0 276 Freescale Semiconductor Chapter 15 Development Support 15.4.3.9 Debug Status Register (DBGS) This is a read-only status register. R 7 6 5 4 3 2 1 0 AF BF ARMF 0 CNT3 CNT2 CNT1 CNT0 0 0 0 0 0 0 0 0 W Reset = Unimplemented or Reserved Figure 15-9. Debug Status Register (DBGS) Table 15-6. DBGS Register Field Descriptions Field Description 7 AF Trigger Match A Flag — AF is cleared at the start of a debug run and indicates whether a trigger match A condition was met since arming. 0 Comparator A has not matched 1 Comparator A match 6 BF Trigger Match B Flag — BF is cleared at the start of a debug run and indicates whether a trigger match B condition was met since arming. 0 Comparator B has not matched 1 Comparator B match 5 ARMF Arm Flag — While DBGEN = 1, this status bit is a read-only image of ARM in DBGC. This bit is set by writing 1 to the ARM control bit in DBGC (while DBGEN = 1) and is automatically cleared at the end of a debug run. A debug run is completed when the FIFO is full (begin trace) or when a trigger event is detected (end trace). A debug run can also be ended manually by writing 0 to ARM or DBGEN in DBGC. 0 Debugger not armed 1 Debugger armed 3:0 CNT[3:0] FIFO Valid Count — These bits are cleared at the start of a debug run and indicate the number of words of valid data in the FIFO at the end of a debug run. The value in CNT does not decrement as data is read out of the FIFO. The external debug host is responsible for keeping track of the count as information is read out of the FIFO. 0000 Number of valid words in FIFO = No valid data 0001 Number of valid words in FIFO = 1 0010 Number of valid words in FIFO = 2 0011 Number of valid words in FIFO = 3 0100 Number of valid words in FIFO = 4 0101 Number of valid words in FIFO = 5 0110 Number of valid words in FIFO = 6 0111 Number of valid words in FIFO = 7 1000 Number of valid words in FIFO = 8 MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 277 Chapter 15 Development Support MC9S08AW60 Data Sheet, Rev.1.0 278 Freescale Semiconductor Appendix A Electrical Characteristics and Timing Specifications A.1 Introduction This section contains electrical and timing specifications. A.2 Parameter Classification The electrical parameters shown in this supplement are guaranteed by various methods. To give the customer a better understanding the following classification is used and the parameters are tagged accordingly in the tables where appropriate: Table A-1. Parameter Classifications P Those parameters are guaranteed during production testing on each individual device. C Those parameters are achieved by the design characterization by measuring a statistically relevant sample size across process variations. T Those parameters are achieved by design characterization on a small sample size from typical devices under typical conditions unless otherwise noted. All values shown in the typical column are within this category. D Those parameters are derived mainly from simulations. NOTE The classification is shown in the column labeled “C” in the parameter tables where appropriate. A.3 Absolute Maximum Ratings Absolute maximum ratings are stress ratings only, and functional operation at the maxima is not guaranteed. Stress beyond the limits specified in Table A-2 may affect device reliability or cause permanent damage to the device. For functional operating conditions, refer to the remaining tables in this section. This device contains circuitry protecting against damage due to high static voltage or electrical fields; however, it is advised that normal precautions be taken to avoid application of any voltages higher than maximum-rated voltages to this high-impedance circuit. Reliability of operation is enhanced if unused inputs are tied to an appropriate logic voltage level (for instance, either VSS or VDD). MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 279 Appendix A Electrical Characteristics and Timing Specifications Table A-2. Absolute Maximum Ratings Rating Symbol Value Unit Supply voltage VDD –0.3 to + 5.8 V Input voltage VIn – 0.3 to VDD + 0.3 V Instantaneous maximum current Single pin limit (applies to all port pins)1, 2, 3 ID ± 25 mA Maximum current into VDD IDD 120 mA Storage temperature Tstg –55 to +150 °C TJ 150 °C Maximum junction temperature 1 Input must be current limited to the value specified. To determine the value of the required current-limiting resistor, calculate resistance values for positive (VDD) and negative (VSS) clamp voltages, then use the larger of the two resistance values. 2 All functional non-supply pins are internally clamped to VSS and VDD. 3 Power supply must maintain regulation within operating V DD range during instantaneous and operating maximum current conditions. If positive injection current (VIn > VDD) is greater than IDD, the injection current may flow out of VDD and could result in external power supply going out of regulation. Ensure external VDD load will shunt current greater than maximum injection current. This will be the greatest risk when the MCU is not consuming power. Examples are: if no system clock is present, or if the clock rate is very low which would reduce overall power consumption. MC9S08AW60 Data Sheet, Rev.1.0 280 Freescale Semiconductor Appendix A Electrical Characteristics and Timing Specifications A.4 Thermal Characteristics This section provides information about operating temperature range, power dissipation, and package thermal resistance. Power dissipation on I/O pins is usually small compared to the power dissipation in on-chip logic and it is user-determined rather than being controlled by the MCU design. In order to take PI/O into account in power calculations, determine the difference between actual pin voltage and VSS or VDD and multiply by the pin current for each I/O pin. Except in cases of unusually high pin current (heavy loads), the difference between pin voltage and VSS or VDD will be very small. Table A-3. Thermal Characteristics Rating Symbol Value Unit Thermal resistance 1,2,3,4 64-pin QFP 1s 2s2p 57 43 64-pin LQFP 1s 2s2p θJA 69 54 °C/W 48-pin QFN 1s 2s2p 84 27 1s 2s2p 73 56 44-pin LQFP 1 Junction temperature is a function of die size, on-chip power dissipation, package thermal resistance, mounting site (board) temperature, ambient temperature, air flow, power dissipation of other components on the board, and board thermal resistance. 2 Junction to Ambient Natural Convection 3 1s - Single Layer Board, one signal layer 4 2s2p - Four Layer Board, 2 signal and 2 power layers The average chip-junction temperature (TJ) in °C can be obtained from: TJ = TA + (PD × θJA) Eqn. A-1 where: TA = Ambient temperature, °C θJA = Package thermal resistance, junction-to-ambient, °C/W PD = Pint + PI/O Pint = IDD × VDD, Watts — chip internal power PI/O = Power dissipation on input and output pins — user determined For most applications, PI/O << Pint and can be neglected. An approximate relationship between PD and TJ (if PI/O is neglected) is: PD = K ÷ (TJ + 273°C) Eqn. A-2 MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 281 Appendix A Electrical Characteristics and Timing Specifications Solving equations 1 and 2 for K gives: K = PD × (TA + 273°C) + θJA × (PD)2 Eqn. A-3 where K is a constant pertaining to the particular part. K can be determined from equation 3 by measuring PD (at equilibrium) for a known TA. Using this value of K, the values of PD and TJ can be obtained by solving equations 1 and 2 iteratively for any value of TA. A.5 ESD Protection and Latch-Up Immunity Although damage from electrostatic discharge (ESD) is much less common on these devices than on early CMOS circuits, normal handling precautions should be used to avoid exposure to static discharge. Qualification tests are performed to ensure that these devices can withstand exposure to reasonable levels of static without suffering any permanent damage. All ESD testing is in conformity with AEC-Q100 Stress Test Qualification for Automotive Grade Integrated Circuits. During the device qualification ESD stresses were performed for the Human Body Model (HBM), the Machine Model (MM) and the Charge Device Model (CDM). A device is defined as a failure if after exposure to ESD pulses the device no longer meets the device specification. Complete DC parametric and functional testing is performed per the applicable device specification at room temperature followed by hot temperature, unless specified otherwise in the device specification. Table A-4. ESD and Latch-up Test Conditions Model Human Body Machine Description Symbol Value Unit Series Resistance R1 1500 Ω Storage Capacitance C 100 pF Number of Pulse per pin — 3 Series Resistance R1 0 Ω Storage Capacitance C 200 pF Number of Pulse per pin — 3 Series Resistance R1 Ω C pF Charge Device Storage Capacitance Model Number of Pulse per pin — Minimum input voltage limit –2.5 V Maximum input voltage limit 7.5 V Latch-Up MC9S08AW60 Data Sheet, Rev.1.0 282 Freescale Semiconductor Appendix A Electrical Characteristics and Timing Specifications Table A-5. ESD and Latch-Up Protection Characteristics Num C A.6 Rating Symbol Min Max Unit 1 C Human Body Model (HBM) VHBM ± 2000 — V 2 C Machine Model (MM) VMM ± 200 — V 3 C Charge Device Model (CDM) VCDM ± 500 — V 4 C Latch-up Current at TA = 125°C ILAT ± 100 — mA DC Characteristics This section includes information about power supply requirements, I/O pin characteristics, and power supply current in various operating modes. Table A-6. MCU Operating Conditions Characteristic Supply Voltage Min Typ Max Uni t 2.7 — 5.5 V –40 –40 — — 125 85 Min Typ1 Max VDD – 1.5 VDD – 1.5 VDD – 0.8 VDD – 0.8 — — — — — — — — °C Temperature M C Table A-7. DC Characteristics Num C Parameter Symbol Output high voltage — Low Drive (PTxDSn = 0) 5 V, ILoad = –2 mA 3 V, ILoad = –0.6 mA 5 V, ILoad = –0.4 mA 3 V, ILoad = –0.24 mA 1 P Output high voltage — High Drive (PTxDSn = 1) 5 V, ILoad = –10 mA 3 V, ILoad = –3 mA 5 V, ILoad = –2 mA 3 V, ILoad = –0.4 mA V VOH VDD – 1.5 VDD – 1.5 VDD – 0.8 VDD – 0.8 — — — — — — — — — — — — — — — — 1.5 1.5 0.8 0.8 — — — — — — — — 1.5 1.5 0.8 0.8 Output low voltage — Low Drive (PTxDSn = 0) 5 V, ILoad = 2 mA 3 V, ILoad = 0.6 mA 5 V, ILoad = 0.4 mA 3 V, ILoad = 0.24 mA 2 P Output low voltage — High Drive (PTxDSn = 1) 5 V, ILoad = 10 mA 3 V, ILoad = 3 mA 5 V, ILoad = 2 mA 3 V, ILoad = 0.4 mA Unit V VOL MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 283 Appendix A Electrical Characteristics and Timing Specifications Table A-7. DC Characteristics (continued) Num C 3 4 Parameter D Output high current — Max total IOH for all ports 5V 3V Symbol Min Typ1 Max Unit IOHT — — — — 100 60 mA IOLT — — — — 100 60 mA D Output low current — Max total IOL for all ports 5V 3V 5 P Input high voltage; all digital inputs VIH 0.65 x VDD — — 6 P Input low voltage; all digital inputs VIL — — 0.35 x VDD 7 T Input hysteresis; all digital inputs Vhys 0.06 x VDD |IIn| — 0.01 8 P Input leakage current; input only pins 2 2 V mV 1 µA 9 P High Impedance (off-state) leakage current |IOZ| — 0.01 1 µA 10 P Internal pullup resistors3 RPU 20 45 65 kΩ 11 P Internal pulldown resistors4 RPD 20 45 65 kΩ 12 C Input Capacitance; all non-supply pins CIn — — 8 pF 13 P POR rearm voltage VPOR 0.9 1.4 2.0 V 14 D POR rearm time tPOR 10 — — µs 15 P Low-voltage detection threshold — high range VDD falling VDD rising VLVDH 4.2 4.3 4.3 4.4 4.4 4.5 V VLVDL 2.48 2.54 2.56 2.62 2.64 2.7 V 16 P Low-voltage detection threshold — low range VDD falling VDD rising 17 P Low-voltage warning threshold — high range VDD falling VLVWH VDD rising 4.2 4.3 4.3 4.4 4.4 4.5 V 18 P Low-voltage warning threshold — low range VDD falling VLVWL VDD rising 2.48 2.54 2.56 2.62 2.64 2.7 V 19 P — — 100 60 — — mV Low-voltage inhibit reset/recover hysteresis 5V 3V Vhys 1 Typical values are based on characterization data at 25°C unless otherwise stated. Measured with VIn = VDD or VSS. 3 Measured with V = V . In SS 4 Measured with V = V . In DD 2 MC9S08AW60 Data Sheet, Rev.1.0 284 Freescale Semiconductor Appendix A Electrical Characteristics and Timing Specifications VDD–VOH (V) Average of IOH –6.0E-3 –5.0E-3 –40°C 25°C 125°C IOH (A) –4.0E-3 –3.0E-3 –2.0E-3 –1.0E-3 000E+0 0 0.3 0.5 0.8 VSupply–VOH 0.9 1.2 1.5 Figure A-1. Typical IOH (Low Drive) vs VDD–VOH at VDD = 3 V VDD–VOH (V) Average of IOH –20.0E-3 –18.0E-3 –16.0E-3 –14.0E-3 –12.0E-3 –10.0E-3 –8.0E-3 –6.0E-3 –4.0E-3 –2.0E-3 000.0E-3 IOH (A) –40°C 25°C 125°C 0 0.3 0.5 0.8 VSupply–VOH 0.9 1.2 1.5 Figure A-2. Typical IOH (High Drive) vs VDD–VOH at VDD = 3 V MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 285 Appendix A Electrical Characteristics and Timing Specifications Average of IOH –7.0E-3 –40°C 25°C 125°C –6.0E-3 –5.0E-3 IOH (A) –4.0E-3 –3.0E-3 –2.0E-3 –1.0E-3 000E+0 0.00 0.30 0.50 0.80 1.00 1.30 2.00 VDD–VOH (V) VSupply–VOH Figure A-3. Typical IOH (Low Drive) vs VDD–VOH at VDD = 5 V VDD–VOH (V) Average of IOH –30.0E-3 –25.0E-3 –40°C 25°C 125°C IOH (A) –20.0E-3 –15.0E-3 –10.0E-3 –5.0E-3 000.0E+3 0.00 0.30 0.50 0.80 1.00 1.30 2.00 VSupply–VOH Figure A-4. Typical IOH (High Drive) vs VDD–VOH at VDD = 5 V MC9S08AW60 Data Sheet, Rev.1.0 286 Freescale Semiconductor Appendix A Electrical Characteristics and Timing Specifications A.7 Supply Current Characteristics Table A-8. Supply Current Characteristics Num C Parameter 1 P Run supply current measured at (CPU clock = 2 MHz, fBus = 1 MHz) 2 P Run supply current measured at (CPU clock = 16 MHz, fBus = 8 MHz) Symbol 2 RIDD 2 RIDD VDD (V) Typ1 Max 5 0.750 0.950 3 0.570 0.770 5 4.9 5.10 3 3.5 3.70 5 0.900 3 Unit Temp (°C) mA –40 to 125°C mA –40 to 125°C 7.5 604 µA –40 to 85°C –40 to 125°C 0.720 7.0 50 µA –40 to 85°C –40 to 125°C 5 0.975 8.0 904 µA –40 to 85°C –40 to 125°C 3 0.825 7.1 85 µA –40 to 85°C –40 to 125°C 5 300 500 500 nA –40 to 85°C –40 to 125°C 3 300 500 500 nA –40 to 85°C –40 to 125°C 5 110 180 µA –40 to 125°C 3 90 160 µA –40 to 125°C 5,3 5 8 µA –40 to 125°C Stop2 mode supply current 3 P S2IDD Stop3 mode supply current 4 5 P C S3IDD RTI adder to stop2 or stop33 6 C LVD adder to stop3 (LVDE = LVDSE = 1) 7 C Adder to stop3 for oscillator enabled4 (OSCSTEN =1) S23IDDRTI S3IDDLVD S3IDDOSC 1 Typical values are based on characterization data at 25°C unless otherwise stated. See Figure A-5 through Figure A-7 for typical curves across voltage/temperature. 2 All modules except ADC active, ICG configured for FBE, and does not include any dc loads on port pins 3 Most customers are expected to find that auto-wakeup from stop2 or stop3 can be used instead of the higher current wait mode. Wait mode typical is 220 µA at 5 V with fBus = 1 MHz. 4 Values given under the following conditions: low range operation (RANGE = 0) with a 32.768kHz crystal, low power mode (HGO = 0), clock monitor disabled (LOCD = 1). MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 287 Appendix A Electrical Characteristics and Timing Specifications 5 IDD (mA) 4 FBE, 1 MHz bus 3 FEE, 4 MHz reference, 1 MHz bus 2 FBE, 8 MHz bus 1 0 2.5 3 3.5 4 4.5 5 5.5 6 VDD (V) Figure A-5. Typical Run IDD for FBE and FEE Modes, IDD vs. VDD Stop2 IDD (A) Average of Meas IDD Stop2 IDD (A) 4.000E–05 3.500E–05 3.000E–05 2.500E–05 Temp –40 25 85 125 2.000E–05 1.500E–05 1.000E–05 5.000E–06 0.000E+00 1.8 2 2.5 3 3.5 VDD (V) 4 4.5 5 Figure A-6. Typical Stop 2 IDD MC9S08AW60 Data Sheet, Rev.1.0 288 Freescale Semiconductor Appendix A Electrical Characteristics and Timing Specifications Stop3 IDD (A) IDD (A) Average of Meas IDD 50.0E–6 45.0E–6 40.0E–6 35.0E–6 30.0E–6 25.0E–6 20.0E–6 15.0E–6 10.0E–6 5.0E–6 000.0E+0 Temp –40 25 85 125 1.8 2 3 2.5 3.5 VDD (V) 4 4.5 5 Figure A-7. Typical Stop3 IDD A.8 ADC Characteristics Table A-9. 5 Volt 10-bit ADC Operating Conditions Symb Min Typ1 Max Unit Absolute VDDAD 2.7 — 5.5 V Delta to VDD (VDD–VDDAD)2 ∆VDDAD –100 0 +100 mV Delta to VSS (VSS–VSSAD)2 ∆VSSAD –100 0 +100 mV Ref voltage high VREFH 2.7 VDDAD VDDAD V Ref voltage low VREFL VSSAD VSSAD VSSAD V Input voltage VADIN VREFL — VREFH V Input capacitance CADIN — 4.5 5.5 pF Input resistance RADIN — 3 5 kΩ — — — — 5 10 — — 10 0.4 — 8.0 0.4 — 4.0 Characteristic Supply voltage Ground voltage Analog source resistance External to MCU Conditions 10-bit mode fADCK > 4MHz fADCK < 4MHz 8-bit mode (all valid fADCK) ADC conversion clock frequency High speed (ADLPC = 0) kΩ RAS fADCK Low power (ADLPC = 1) MHz 1 Typical values assume VDDAD = 5.0 V, Temp = 25°C, fADCK = 1.0MHz unless otherwise stated. Typical values are for reference only and are not tested in production. 2 dc potential difference. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 289 Appendix A Electrical Characteristics and Timing Specifications SIMPLIFIED INPUT PIN EQUIVALENT CIRCUIT ZADIN SIMPLIFIED CHANNEL SELECT CIRCUIT Pad leakage due to input protection ZAS RAS ADC SAR ENGINE RADIN + VADIN VAS CAS + – – RADIN INPUT PIN RADIN INPUT PIN RADIN INPUT PIN CADIN Figure A-8. ADC Input Impedance Equivalency Diagram Table A-10. 10-bit ADC Characteristics (VREFH = VDDAD, VREFL = VSSAD) C Symb Min Typ1 Max Unit Supply current ADLPC = 1 ADLSMP = 1 ADCO = 1 T IDDAD — 133 — µA Supply current ADLPC = 1 ADLSMP = 0 ADCO = 1 T IDDAD — 218 — µA Supply current ADLPC = 0 ADLSMP = 1 ADCO = 1 T IDDAD — 327 — µA P IDDAD — 582 990 µA IDDAD — 0.011 1 µA fADACK 2 3.3 5 MHzS 1.25 2 3.3 — 20 — — 40 — Characteristic Conditions Supply current ADLPC = 0 ADLSMP = 0 ADCO = 1 VDDAD < 5.5 V Supply current Stop, reset, module off ADC asynchronous clock source tADACK = 1/fADACK High speed (ADLPC = 0) Conversion time (Including sample time) P Low power (ADLPC = 1) Short sample (ADLSMP = 0) P tADC Long sample (ADLSMP = 1) ADCK cycles MC9S08AW60 Data Sheet, Rev.1.0 290 Freescale Semiconductor Appendix A Electrical Characteristics and Timing Specifications Table A-10. 10-bit ADC Characteristics (VREFH = VDDAD, VREFL = VSSAD) (continued) Characteristic Sample time Conditions C Symb Min Typ1 Max Unit Short sample (ADLSMP = 0) P tADS — 3.5 — — 23.5 — ADCK cycles — ±1 ±2.5 — ±0.5 ±1.0 — ±0.5 ±1.0 — ±0.3 ±0.5 Long sample (ADLSMP = 1) Total unadjusted error Includes quantization Differential non-linearity 10-bit mode P ETUE 8-bit mode 10-bit mode P DNL 8-bit mode LSB2 LSB2 Monotonicity and no-missing-codes guaranteed Integral non-linearity 10-bit mode C INL 8-bit mode Zero-scale error VADIN = VSSA 10-bit mode Full-scale error VADIN = VDDA 10-bit mode Quantization error 10-bit mode P EZS 8-bit mode P EFS 8-bit mode D EQ 8-bit mode Input leakage error Pad leakage3 * RAS 10-bit mode D EIL 8-bit mode — ±0.5 ±1.0 — ±0.3 ±0.5 — ±0.5 ±1.5 — ±0.5 ±0.5 — ±0.5 ±1.5 — ±0.5 ±0.5 — — ±0.5 — — ±0.5 — ±0.2 ±2.5 — ±0.1 ±1 LSB2 LSB2 LSB2 LSB2 LSB2 1 Typical values assume VDDAD = 5.0V, Temp = 25C, fADCK=1.0 MHz unless otherwise stated. Typical values are for reference only and are not tested in production. 2 1 LSB = (V N REFH – VREFL)/2 3 Based on input pad leakage current. Refer to pad electricals. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 291 Appendix A Electrical Characteristics and Timing Specifications A.9 Internal Clock Generation Module Characteristics ICG EXTAL XTAL RS RF C1 Crystal or Resonator C2 Table A-11. ICG DC Electrical Specifications (Temperature Range = –40 to 125°C Ambient) Characteristic Load capacitors Feedback resistor Low range (32k to 100 kHz) High range (1M – 16 MHz) Series resistor Low range Low Gain (HGO = 0) High Gain (HGO = 1) High range Low Gain (HGO = 0) High Gain (HGO = 1) ≥ 8 MHz 4 MHz 1 MHz 1 2 Symbol Min Typ1 Max C1 C2 See Note 2 RF 10 1 RS Unit MΩ MΩ — — 0 100 — — — 0 — — — — 0 10 20 — — — kΩ Typical values are based on characterization data at VDD = 5.0V, 25°C or is typical recommended value. See crystal or resonator manufacturer’s recommendation. MC9S08AW60 Data Sheet, Rev.1.0 292 Freescale Semiconductor Appendix A Electrical Characteristics and Timing Specifications A.9.1 ICG Frequency Specifications Table A-12. ICG Frequency Specifications (VDDA = VDDA (min) to VDDA (max), Temperature Range = –40 to 125°C Ambient) Symbol Min Typ1 Max Unit flo 32 — 100 kHz fhi_byp fhi_eng flp_byp flp_eng 1 2 1 2 — — 16 10 8 8 MHz MHz MHz MHz Input clock frequency (CLKS = 11, REFS = 0) Low range High range flo fhi_eng 32 2 — — 100 10 kHz MHz T Input clock frequency (CLKS = 10, REFS = 0) fExtal 0 — 40 MHz 4 P Internal reference frequency (untrimmed) fICGIRCLK 182.25 243 303.75 kHz 5 P Duty cycle of input clock (REFS = 0) tdc 40 — 60 % P Output clock ICGOUT frequency CLKS = 10, REFS = 0 All other cases fICGOUT fExtal (min) flo (min) — — fExtal (max) fICGDCLKmax( max) MHz 8 — Num C Characteristic 1 T Oscillator crystal or resonator (REFS = 1) (Fundamental mode crystal or ceramic resonator) Low range High range High Gain, FBE (HGO = 1,CLKS = 10) High Gain, FEE (HGO = 1,CLKS = 11) Low Power, FBE (HGO = 0, CLKS = 10) Low Power, FEE (HGO = 0, CLKS = 11) 2 T 3 6 7 Minimum DCO clock (ICGDCLK) frequency fICGDCLKmin 8 Maximum DCO clock (ICGDCLK) frequency fICGDCLKmax 9 P Self-clock mode (ICGOUT) frequency 2 10 P Self-clock mode reset (ICGOUT) frequency 11 T Loss of reference frequency Low range High range 12 T Loss of DCO frequency 4 MHz MHz 10.5 MHz 5 50 25 500 kHz fLOD 0.5 1.5 MHz t CSTL t CSTH — — — — ms fICGDCLKmin fSelf_reset 5.5 fLOR 8 3 5, 6 Crystal start-up time Low range High range 14 P FLL lock time , 7 Low range High range tLockl tLockh — — 5 5 ms 15 T FLL frequency unlock range nUnlock –4*N 4*N counts 16 T FLL frequency lock range nLock –2*N 2*N counts CJitter — 0.2 % fICG ACCint — — ±2 ±2 % 17 18 2 40 fICGDCLKmax fSelf T 13 1 — MHz T P C , 8 measured at fICGOUT Max ICGOUT period jitter, Long term jitter (averaged over 2 ms interval) Internal oscillator deviation from trimmed frequency9 VDD = 2.7 – 5.5 V, (constant temperature) VDD = 5.0 V ±10%, –40° C to 125°C 430 4 ± 0.5 ±0.5 Typical values are based on characterization data at VDD = 5.0V, 25°C unless otherwise stated. Self-clocked mode frequency is the frequency that the DCO generates when the FLL is open-loop. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 293 Appendix A Electrical Characteristics and Timing Specifications 3 4 5 6 7 8 9 Loss of reference frequency is the reference frequency detected internally, which transitions the ICG into self-clocked mode if it is not in the desired range. Loss of DCO frequency is the DCO frequency detected internally, which transitions the ICG into FLL bypassed external mode (if an external reference exists) if it is not in the desired range. This parameter is characterized before qualification rather than 100% tested. Proper PC board layout procedures must be followed to achieve specifications. This specification applies to the period of time required for the FLL to lock after entering FLL engaged internal or external modes. If a crystal/resonator is being used as the reference, this specification assumes it is already running. Jitter is the average deviation from the programmed frequency measured over the specified interval at maximum fICGOUT. Measurements are made with the device powered by filtered supplies and clocked by a stable external clock signal. Noise injected into the FLL circuitry via VDDA and VSSA and variation in crystal oscillator frequency increase the CJitter percentage for a given interval. See Figure A-9 Internal Oscillator Deviation from Trimmed Frequency Variable 5V 3V 0.0 Percent (%) –0.5 –1.0 –1.5 –2.0 –50 –25 0 25 50 Temp 75 100 125 Device trimmed at 25°C at 3.0 V. Figure A-9. Internal Oscillator Deviation from Trimmed Frequency MC9S08AW60 Data Sheet, Rev.1.0 294 Freescale Semiconductor Appendix A Electrical Characteristics and Timing Specifications A.10 AC Characteristics This section describes ac timing characteristics for each peripheral system. For detailed information about how clocks for the bus are generated, see Chapter 8, “Internal Clock Generator (S08ICGV4).” A.10.1 Control Timing Table A-13. Control Timing Num 1 2 Symbol Min Typ1 Max Unit Bus frequency (tcyc = 1/fBus) fBus dc — 20 MHz Real-time interrupt internal oscillator period tRTI 700 1300 µs C P Parameter 3 External reset pulse width2 (tcyc = 1/fSelf_reset) textrst 1.5 x tSelf_reset — ns 4 Reset low drive3 trstdrv 34 x tcyc — ns 5 Active background debug mode latch setup time tMSSU 25 — ns 6 Active background debug mode latch hold time tMSH 25 — ns 7 IRQ pulse width Asynchronous path2 Synchronous path4 tILIH, tIHIL 100 1.5 x tcyc — — ns KBIPx pulse width Asynchronous path2 Synchronous path3 tILIH, tIHIL 100 1.5 x tcyc — — ns Port rise and fall time — Low output drive (PTxDS = 0) (load = 50 pF)5 Slew rate control disabled (PTxSE = 0) Slew rate control enabled (PTxSE = 1) tRise, tFall — — 40 75 — — Port rise and fall time — High output drive (PTxDS = 1) (load = 50 pF) Slew rate control disabled (PTxSE = 0) Slew rate control enabled (PTxSE = 1) tRise, tFall — — 11 35 — — 8 9 T ns ns 1 Typical values are based on characterization data at VDD = 5.0V, 25°C unless otherwise stated. This is the shortest pulse that is guaranteed to be recognized as a reset pin request. Shorter pulses are not guaranteed to override reset requests from internal sources. 3 When any reset is initiated, internal circuitry drives the reset pin low for about 34 bus cycles and then samples the level on the reset pin about 38 bus cycles later to distinguish external reset requests from internal requests. 4 This is the minimum pulse width that is guaranteed to pass through the pin synchronization circuitry. Shorter pulses may or may not be recognized. In stop mode, the synchronizer is bypassed so shorter pulses can be recognized in that case. 5 Timing is shown with respect to 20% V DD and 80% VDD levels. Temperature range –40°C to 125°C. 2 textrst RESET PIN Figure A-10. Reset Timing MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 295 Appendix A Electrical Characteristics and Timing Specifications BKGD/MS RESET tMSH tMSSU Figure A-11. Active Background Debug Mode Latch Timing tIHIL IRQ/KBIP7-KBIP4 IRQ/KBIPx tILIH Figure A-12. IRQ/KBIPx Timing A.10.2 Timer/PWM (TPM) Module Timing Synchronizer circuits determine the shortest input pulses that can be recognized or the fastest clock that can be used as the optional external source to the timer counter. These synchronizers operate from the current bus rate clock. Table A-14. TPM Input Timing Function Symbol Min Max Unit External clock frequency fTPMext dc fBus/4 Hz External clock period tTPMext 4 — tcyc External clock high time tclkh 1.5 — tcyc External clock low time tclkl 1.5 — tcyc tICPW 1.5 — tcyc Input capture pulse width MC9S08AW60 Data Sheet, Rev.1.0 296 Freescale Semiconductor Appendix A Electrical Characteristics and Timing Specifications tTPMext tclkh TPMxCLK tclkl Figure A-13. Timer External Clock tICPW TPMxCHn TPMxCHn tICPW Figure A-14. Timer Input Capture Pulse MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 297 Appendix A Electrical Characteristics and Timing Specifications A.11 SPI Characteristics Table A-15 and Figure A-15 through Figure A-18 describe the timing requirements for the SPI system. Table A-15. SPI Electrical Characteristic Num1 C Characteristic2 Symbol Min Max Unit Master Slave fop fop fBus/2048 dc fBus/2 fBus/4 Hz Master Slave tSCK tSCK 2 4 2048 — tcyc tcyc Master Slave tLead tLead — 1/2 1/2 — tSCK tSCK Master Slave tLag tLag — 1/2 1/2 — tSCK tSCK Clock (SPSCK) high time Master and Slave tSCKH 1/2 tSCK – 25 — ns Clock (SPSCK) low time Master and Slave tSCKL 1/2 tSCK – 25 — ns Master Slave tSI(M) tSI(S) 30 30 — — ns ns Master Slave tHI(M) tHI(S) 30 30 — — ns ns Operating frequency3 1 2 3 4 5 6 7 Cycle time Enable lead time Enable lag time Data setup time (inputs) Data hold time (inputs) 8 Access time, slave4 tA 0 40 ns 9 Disable time, slave5 tdis — 40 ns 10 Data setup time (outputs) Master Slave tSO tSO 25 25 — — ns ns tHO tHO –10 –10 — — ns ns 11 Data hold time (outputs) Master Slave 1 Refer to Figure A-15 through Figure A-18. All timing is shown with respect to 20% VDD and 70% VDD, unless noted; 100 pF load on all SPI pins. All timing assumes slew rate control disabled and high drive strength enabled for SPI output pins. 3 Maximum baud rate must be limited to 5 MHz due to pad input characteristics. 4 Time to data active from high-impedance state. 5 Hold time to high-impedance state. 2 MC9S08AW60 Data Sheet, Rev.1.0 298 Freescale Semiconductor Appendix A Electrical Characteristics and Timing Specifications SS1 (OUTPUT) 1 2 SCK (CPOL = 0) (OUTPUT) 3 5 4 SCK (CPOL = 1) (OUTPUT) 5 4 6 MISO (INPUT) 7 MSB IN2 BIT 6 . . . 1 10 MOSI (OUTPUT) LSB IN 10 MSB OUT2 11 BIT 6 . . . 1 LSB OUT NOTES: 1. SS output mode (MODFEN = 1, SSOE = 1). 2. LSBF = 0. For LSBF = 1, bit order is LSB, bit 1, ..., bit 6, MSB. Figure A-15. SPI Master Timing (CPHA = 0) SS(1) (OUTPUT) 1 2 SCK (CPOL = 0) (OUTPUT) 3 5 4 SCK (CPOL = 1) (OUTPUT) 5 4 6 MISO (INPUT) 7 MSB IN(2) 10 MOSI (OUTPUT) BIT 6 . . . 1 LSB IN 11 MSB OUT(2) BIT 6 . . . 1 LSB OUT NOTES: 1. SS output mode (MODFEN = 1, SSOE = 1). 2. LSBF = 0. For LSBF = 1, bit order is LSB, bit 1, ..., bit 6, MSB. Figure A-16. SPI Master Timing (CPHA = 1) MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 299 Appendix A Electrical Characteristics and Timing Specifications SS (INPUT) 3 1 SCK (CPOL = 0) (INPUT) 5 4 2 SCK (CPOL = 1) (INPUT) 5 4 8 MISO (OUTPUT) 11 10 BIT 6 . . . 1 MSB OUT SLAVE SEE NOTE SLAVE LSB OUT 7 6 MOSI (INPUT) 9 BIT 6 . . . 1 MSB IN LSB IN NOTE: 1. Not defined but normally MSB of character just received Figure A-17. SPI Slave Timing (CPHA = 0) SS (INPUT) 1 3 2 SCK (CPOL = 0) (INPUT) 5 4 SCK (CPOL = 1) (INPUT) 5 4 10 MISO (OUTPUT) SEE NOTE 8 MOSI (INPUT) SLAVE 11 MSB OUT 6 BIT 6 . . . 1 9 SLAVE LSB OUT 7 MSB IN BIT 6 . . . 1 LSB IN NOTE: 1. Not defined but normally LSB of character just received Figure A-18. SPI Slave Timing (CPHA = 1) MC9S08AW60 Data Sheet, Rev.1.0 300 Freescale Semiconductor Appendix A Electrical Characteristics and Timing Specifications A.12 FLASH Specifications This section provides details about program/erase times and program-erase endurance for the FLASH memory. Program and erase operations do not require any special power sources other than the normal VDD supply. For more detailed information about program/erase operations, see Chapter 4, “Memory.” Table A-16. FLASH Characteristics Num C 1 P 2 Characteristic Symbol Min Supply voltage for program/erase Vprog/erase P Supply voltage for read operation 3 P 4 Typ1 Max Unit 2.7 5.5 V VRead 2.7 5.5 V Internal FCLK frequency2 fFCLK 150 200 kHz P Internal FCLK period (1/FCLK) tFcyc 5 6.67 µs 5 P Byte program time (random location)(2) tprog 9 tFcyc 6 C Byte program time (burst mode)(2) tBurst 4 tFcyc 7 P Page erase time3 tPage 4000 tFcyc 8 P Mass erase time(2) tMass 20,000 tFcyc 9 C Program/erase endurance4 TL to TH = –40°C to + 125°C T = 25°C 10 C Data retention5 tD_ret 10,000 — — 100,000 — — cyces 15 100 — years 1 Typical values are based on characterization data at VDD = 5.0 V, 25°C unless otherwise stated. The frequency of this clock is controlled by a software setting. 3 These values are hardware state machine controlled. User code does not need to count cycles. This information supplied for calculating approximate time to program and erase. 4 Typical endurance for FLASH was evaluated for this product family on the 9S12Dx64. For additional information on how Freescale Semiconductor defines typical endurance, please refer to Engineering Bulletin EB619/D, Typical Endurance for Nonvolatile Memory. 5 Typical data retention values are based on intrinsic capability of the technology measured at high temperature and de-rated to 25°C using the Arrhenius equation. For additional information on how Freescale Semiconductor defines typical data retention, please refer to Engineering Bulletin EB618/D, Typical Data Retention for Nonvolatile Memory. 2 MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 301 Appendix A Electrical Characteristics and Timing Specifications A.13 EMC Performance Electromagnetic compatibility (EMC) performance is highly dependant on the environment in which the MCU resides. Board design and layout, circuit topology choices, location and characteristics of external components as well as MCU software operation all play a significant role in EMC performance. The system designer should consult Freescale applications notes such as AN2321, AN1050, AN1263, AN2764, and AN1259 for advice and guidance specifically targeted at optimizing EMC performance. A.13.1 Radiated Emissions Microcontroller radiated RF emissions are measured from 150 kHz to 1 GHz using the TEM/GTEM Cell method in accordance with the IEC 61967-2 and SAE J1752/3 standards. The measurement is performed with the microcontroller installed on a custom EMC evaluation board while running specialized EMC test software. The radiated emissions from the microcontroller are measured in a TEM cell in two package orientations (North and East). For more detailed information concerning the evaluation results, conditions and setup, please refer to the EMC Evaluation Report for this device. The maximum radiated RF emissions of the tested configuration in all orientations are less than or equal to the reported emissions levels. Table A-17. Parameter Symbol Conditions Frequency fOSC/fBUS VRE_TEM VDD = 5.5V TA = +25oC package type 64 QFP 0.15 – 50 MHz 4 MHz crystal 20 MHz Bus Radiated emissions, electric field 1 50 – 150 MHz Level1 (Max) Unit TBD dBµV TBD 150 – 500 MHz TBD 500 – 1000 MHz TBD IEC Level TBD — SAE Level TBD — Data based on qualification test results. A.13.2 Conducted Transient Susceptibility Microcontroller transient conducted susceptibility is measured in accordance with an internal Freescale test method. The measurement is performed with the microcontroller installed on a custom EMC evaluation board and running specialized EMC test software designed in compliance with the test method. The conducted susceptibility is determined by injecting the transient susceptibility signal on each pin of the microcontroller. The transient waveform and injection methodology is based on IEC 61000-4-4 (EFT/B). The transient voltage required to cause performance degradation on any pin in the tested configuration is greater than or equal to the reported levels unless otherwise indicated by footnotes below the table. MC9S08AW60 Data Sheet, Rev.1.0 302 Freescale Semiconductor Appendix A Electrical Characteristics and Timing Specifications Table A-18. Parameter Symbol Conducted susceptibility, electrical fast transient/burst (EFT/B) 1 VCS_EFT Conditions VDD = 5.5V TA = +25oC package type 64 LQFP fOSC/fBUS 4MHz crystal 20MHz Bus Result Amplitude1 (Min) A TBD B TBD C TBD D TBD Unit kV Data based on qualification test results. Not tested in production. The susceptibility performance classification is described in Table A-19. Table A-19. Susceptibility Performance Classification Result Performance Criteria A No failure The MCU performs as designed during and after exposure. B Self-recovering failure C Soft failure The MCU does not perform as designed during exposure. The MCU does not return to normal operation until exposure is removed and the RESET pin is asserted. D Hard failure The MCU does not perform as designed during exposure. The MCU does not return to normal operation until exposure is removed and the power to the MCU is cycled. E Damage The MCU does not perform as designed during and after exposure. The MCU cannot be returned to proper operation due to physical damage or other permanent performance degradation. The MCU does not perform as designed during exposure. The MCU returns automatically to normal operation after exposure is removed. MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 303 Appendix A Electrical Characteristics and Timing Specifications MC9S08AW60 Data Sheet, Rev.1.0 304 Freescale Semiconductor Appendix B Ordering Information and Mechanical Drawings B.1 Ordering Information This section contains ordering numbers for MC9S08AW60/48/32/16 devices. See below for an example of the device numbering system. Table B-1. Device Numbering System Device 1 2 B.2 Available Packages2 Memory Number1 FLASH RAM MC9S08AW60 MC9S08AW48 MC9S08AW32 63,280 49,152 32,768 2048 MC9S08AW16 16,384 1024 Type 64-pin LQFP 64-pin QFP 48-pin QFN 44-pin LQFP See Table 1-1 for a complete description of modules included on each device. See Table B-2 for package information. Orderable Part Numbering System MC 9 S08 AW 60 C XX E Pb free indicator Package designator (See Table B-2) Status (MC = Fully Qualified) Memory (9 = FLASH-based) Core Family B.3 Temperature range (C = –40°C to 85°C) (M = –40°C to 125°C) Memory size designator Mechanical Drawings This following pages contain mechanical specifications for MC9S08AW60/48/32/16 package options. See Table B-2 for the document numbers that correspond to each package type. Table B-2. Package Information Pin Count Type Designator Document No. 44 LQFP FG 98ASS23225W 48 QFN FD 98ARH99048A 64 LQFP PU 98ASS23234W 64 QFP FU 98ASB42844B MC9S08AW60 Data Sheet, Rev.1.0 Freescale Semiconductor 305 How to Reach Us: Information in this document is provided solely to enable system and software implementers to use Freescale Semiconductor products. There are no express or implied copyright licenses granted USA/Europe/Locations not listed: Freescale Semiconductor Literature Distribution P.O. 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