Freescale MC9S08JM16CLCE Microcontroller Datasheet

MC9S08JM16
MC9S08JM8
Data Sheet
HCS08
Microcontrollers
MC9S08JM16
Rev. 2
5/2008
freescale.com
MC9S08JM16 Series Features
8-Bit HCS08 Central Processor Unit (CPU)
•
•
•
•
•
48 MHz HCS08 CPU (central processor unit)
24 MHz internal bus frequency
HC08 instruction set with added BGND instruction
Background debugging system
Breakpoint capability to allow single breakpoint
setting during in-circuit debugging (plus two more
breakpoints in on-chip debug module)
• In-circuit emulator (ICE) debug module containing
two comparators and nine trigger modes. Eight
deep FIFO for storing change-of-flow addresses
and event-only data. Debug module supports both
tag and force breakpoints
• Support for up to 32 interrupt/reset sources
Memory Options
• Up to 16 KB of on-chip in-circuit programmable
flash memory with block protection and security
options
• Up to 1 KB of on-chip RAM
• 256 bytes of USB RAM
Clock Source Options
• Clock source options include crystal, resonator,
external clock
• MCG (multi-purpose clock generator) — PLL and
FLL; internal reference clock with trim adjustment
System Protection
• Optional computer operating properly (COP) reset
with option to run from independent 1 kHz internal
clock source or the bus clock
• Low-voltage detection with reset or interrupt
• Illegal opcode detection with reset
• Illegal address detection with reset
Power-Saving Modes
• Wait plus two stops
Peripherals
• USB — USB 2.0 full-speed (12 Mbps) with
dedicated on-chip 3.3 V regulator and transceiver;
supporting endpoint 0 and up to 6 additional
endpoints
• ADC — 8-channel, 12-bit analog-to-digital
converter with automatic compare function;
internal temperature sensor
• ACMP — Analog comparator with option to
compare to internal reference; operation in stop3
mode
• SCI — Up to two serial communications interface
modules with optional 13-bit break; LIN
extensions
• SPI — Two 8- or 16-bit selectable serial peripheral
interface modules with a receive data buffer
hardware match function
• IIC — Inter-integrated circuit bus module to
operate at up to 100 kbps with maximum bus
loading; multi-master operation; programmable
slave address; interrupt-driven byte-by-byte data
transfer; broadcast mode; 10-bit addressing
• Timers — One 2-channel and one 4-channel
16-bit timer/pulse-width modulator (TPM)
modules; 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 — 7-pin keyboard interrupt module
• RTC — Real-time counter with binary- or
decimal-based prescaler
Input/Output
• Up to 37 general purpose input/output pins
• Software selectable pullup 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
• 48-pin quad flat no-lead (QFN)
• 44-pin low-profile quad flat package (LQFP)
• 32-pin low-profile quad flat package (LQFP)
MC9S08JM16 Data Sheet
Covers: MC9S08JM16
MC9S08JM8
MC9S08JM16
Rev. 2
5/2008
Revision History
To provide the most up-to-date information, the version of this document 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
Rev. 1
3/2008
Initial release.
Rev. 2
5/2008
Added EMC data in appendix.
Description of Changes
This product incorporates SuperFlash® technology licensed from SST.
Freescale™ and the Freescale logo are trademarks of Freescale Semiconductor, Inc.
© Freescale Semiconductor, Inc., 2008. All rights reserved.
MC9S08JM16 Series Data Sheet, Rev. 2
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Freescale Semiconductor
List of Chapters
Chapter Number
Title
Page
Chapter 1 Device Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Chapter 2 Pins and Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Chapter 3 Modes of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Chapter 4 Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Chapter 5 Resets, Interrupts, and System Configuration . . . . . . . . . . . . . . . 61
Chapter 6 Parallel Input/Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
Chapter 7 Central Processor Unit (S08CPUV2) . . . . . . . . . . . . . . . . . . . . . . . 99
Chapter 8 Keyboard Interrupt (S08KBIV2) . . . . . . . . . . . . . . . . . . . . . . . . . . 119
Chapter 9 5 V Analog Comparator (S08ACMPV2) . . . . . . . . . . . . . . . . . . . . 127
Chapter 10 Analog-to-Digital Converter (S08ADC12V1) . . . . . . . . . . . . . . . 133
Chapter 11 Inter-Integrated Circuit (S08IICV2) . . . . . . . . . . . . . . . . . . . . . . . 159
Chapter 12 Multi-Purpose Clock Generator (S08MCGV1) . . . . . . . . . . . . . . 177
Chapter 13 Real-Time Counter (S08RTCV1) . . . . . . . . . . . . . . . . . . . . . . . . . 209
Chapter 14 Serial Communications Interface (S08SCIV4) . . . . . . . . . . . . . . 219
Chapter 15 16-Bit Serial Peripheral Interface (S08SPI16V1) . . . . . . . . . . . . 239
Chapter 16 Timer/Pulse-Width Modulator (S08TPMV2) . . . . . . . . . . . . . . . . 267
Chapter 17 Universal Serial Bus Device Controller (S08USBV1) . . . . . . . . 295
Chapter 18 Development Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 327
Appendix A Electrical Characteristics........................................................... 349
Appendix B Ordering Information and Mechanical Drawings..................... 373
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
7
Contents
Section Number
Title
Page
Chapter 1
Device Overview
1.1
1.2
1.3
Introduction .....................................................................................................................................19
MCU Block Diagram ......................................................................................................................19
System Clock Distribution ..............................................................................................................21
Chapter 2
Pins and Connections
2.1
2.2
2.3
Introduction .....................................................................................................................................23
Device Pin Assignment ...................................................................................................................23
Recommended System Connections ...............................................................................................25
2.3.1 Power (VDD, VSS, VSSOSC, VDDAD, VSSAD, VUSB33) ....................................................27
2.3.2 Oscillator (XTAL, EXTAL) ..............................................................................................27
2.3.3 RESET Pin ........................................................................................................................28
2.3.4 Background/Mode Select (BKGD/MS) ............................................................................28
2.3.5 ADC Reference Pins (VREFH, VREFL) .............................................................................28
2.3.6 External Interrupt Pin (IRQ) .............................................................................................28
2.3.7 USB Data Pins (USBDP, USBDN) ...................................................................................29
2.3.8 General-Purpose I/O and Peripheral Ports ........................................................................29
Chapter 3
Modes of Operation
3.1
3.2
3.3
3.4
3.5
3.6
Introduction .....................................................................................................................................31
Features ...........................................................................................................................................31
Run Mode ........................................................................................................................................31
Active Background Mode ...............................................................................................................31
Wait Mode .......................................................................................................................................32
Stop Modes ......................................................................................................................................33
3.6.1 Stop3 Mode .......................................................................................................................33
3.6.2 Stop2 Mode .......................................................................................................................34
3.6.3 On-Chip Peripheral Modules in Stop Modes ....................................................................35
Chapter 4
Memory
4.1
4.2
4.3
4.4
MC9S08JM16 Series Memory Map ...............................................................................................37
4.1.1 Reset and Interrupt Vector Assignments ...........................................................................39
Register Addresses and Bit Assignments ........................................................................................40
RAM (System RAM) ......................................................................................................................46
USB RAM .......................................................................................................................................47
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4.5
4.6
4.7
Flash ................................................................................................................................................47
4.5.1 Features .............................................................................................................................47
4.5.2 Program and Erase Times .................................................................................................47
4.5.3 Program and Erase Command Execution .........................................................................48
4.5.4 Burst Program Execution ..................................................................................................49
4.5.5 Access Errors ....................................................................................................................51
4.5.6 Flash Block Protection ......................................................................................................52
4.5.7 Vector Redirection ............................................................................................................53
Security ............................................................................................................................................53
Flash Registers and Control Bits .....................................................................................................54
4.7.1 Flash Clock Divider Register (FCDIV) ............................................................................55
4.7.2 Flash Options Register (FOPT and NVOPT) ....................................................................56
4.7.3 Flash Configuration Register (FCNFG) ...........................................................................57
4.7.4 Flash Protection Register (FPROT and NVPROT) ..........................................................57
4.7.5 Flash Status Register (FSTAT) ..........................................................................................58
4.7.6 Flash Command Register (FCMD) ...................................................................................59
Chapter 5
Resets, Interrupts, and System Configuration
5.1
5.2
5.3
5.4
5.5
5.6
5.7
Introduction .....................................................................................................................................61
Features ...........................................................................................................................................61
MCU Reset ......................................................................................................................................61
Computer Operating Properly (COP) Watchdog .............................................................................62
Interrupts .........................................................................................................................................63
5.5.1 Interrupt Stack Frame .......................................................................................................64
5.5.2 External Interrupt Request (IRQ) Pin ...............................................................................64
5.5.3 Interrupt Vectors, Sources, and Local Masks ...................................................................65
Low-Voltage Detect (LVD) System ................................................................................................67
5.6.1 Power-On Reset Operation ...............................................................................................67
5.6.2 LVD Reset Operation ........................................................................................................67
5.6.3 LVD Interrupt Operation ...................................................................................................68
5.6.4 Low-Voltage Warning (LVW) ...........................................................................................68
Reset, Interrupt, and System Control Registers and Control Bits ...................................................68
5.7.1 Interrupt Pin Request Status and Control Register (IRQSC) ............................................68
5.7.2 System Reset Status Register (SRS) .................................................................................69
5.7.3 System Background Debug Force Reset Register (SBDFR) ............................................70
5.7.4 System Options Register 1 (SOPT1) ................................................................................71
5.7.5 System Options Register 2 (SOPT2) ................................................................................72
5.7.6 System Device Identification Register (SDIDH, SDIDL) ................................................73
5.7.7 System Power Management Status and Control 1 Register (SPMSC1) ...........................74
5.7.8 System Power Management Status and Control 2 Register (SPMSC2) ...........................75
Chapter 6
Parallel Input/Output
6.1
Introduction .....................................................................................................................................77
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6.2
6.3
6.4
6.5
Port Data and Data Direction ..........................................................................................................78
Pin Control ......................................................................................................................................79
6.3.1 Internal Pullup Enable ......................................................................................................79
6.3.2 Output Slew Rate Control Enable .....................................................................................79
6.3.3 Output Drive Strength Select ............................................................................................79
Pin Behavior in Stop Modes ............................................................................................................79
Parallel I/O and Pin Control Registers ............................................................................................80
6.5.1 Port A I/O Registers (PTAD and PTADD) ........................................................................80
6.5.2 Port A Pin Control Registers (PTAPE, PTASE, PTADS) .................................................81
6.5.3 Port B I/O Registers (PTBD and PTBDD) ........................................................................82
6.5.4 Port B Pin Control Registers (PTBPE, PTBSE, PTBDS) .................................................83
6.5.5 Port C I/O Registers (PTCD and PTCDD) ........................................................................84
6.5.6 Port C Pin Control Registers (PTCPE, PTCSE, PTCDS) .................................................85
6.5.7 Port D I/O Registers (PTDD and PTDDD) .......................................................................87
6.5.8 Port D Pin Control Registers (PTDPE, PTDSE, PTDDS) ................................................88
6.5.9 Port E I/O Registers (PTED and PTEDD) ........................................................................89
6.5.10 Port E Pin Control Registers (PTEPE, PTESE, PTEDS) ..................................................91
6.5.11 Port F I/O Registers (PTFD and PTFDD) .........................................................................92
6.5.12 Port F Pin Control Registers (PTFPE, PTFSE, PTFDS) ...................................................93
6.5.13 Port G I/O Registers (PTGD and PTGDD) .......................................................................95
6.5.14 Port G Pin Control Registers (PTGPE, PTGSE, PTGDS) ................................................96
Chapter 7
Central Processor Unit (S08CPUV2)
7.1
7.2
7.3
7.4
Introduction .....................................................................................................................................99
7.1.1 Features .............................................................................................................................99
Programmer’s Model and CPU Registers .....................................................................................100
7.2.1 Accumulator (A) .............................................................................................................100
7.2.2 Index Register (H:X) ......................................................................................................100
7.2.3 Stack Pointer (SP) ...........................................................................................................101
7.2.4 Program Counter (PC) ....................................................................................................101
7.2.5 Condition Code Register (CCR) .....................................................................................101
Addressing Modes .........................................................................................................................103
7.3.1 Inherent Addressing Mode (INH) ...................................................................................103
7.3.2 Relative Addressing Mode (REL) ..................................................................................103
7.3.3 Immediate Addressing Mode (IMM) ..............................................................................103
7.3.4 Direct Addressing Mode (DIR) ......................................................................................103
7.3.5 Extended Addressing Mode (EXT) ................................................................................104
7.3.6 Indexed Addressing Mode ..............................................................................................104
Special Operations .........................................................................................................................105
7.4.1 Reset Sequence ...............................................................................................................105
7.4.2 Interrupt Sequence ..........................................................................................................105
7.4.3 Wait Mode Operation ......................................................................................................106
7.4.4 Stop Mode Operation ......................................................................................................106
7.4.5 BGND Instruction ...........................................................................................................107
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Freescale Semiconductor
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7.5
HCS08 Instruction Set Summary ..................................................................................................108
Chapter 8
Keyboard Interrupt (S08KBIV2)
8.1
8.2
8.3
8.4
Introduction ...................................................................................................................................119
8.1.1 Features ...........................................................................................................................121
8.1.2 Modes of Operation ........................................................................................................121
8.1.3 Block Diagram ................................................................................................................121
External Signal Description ..........................................................................................................122
Register Definition ........................................................................................................................122
8.3.1 KBI Status and Control Register (KBISC) .....................................................................122
8.3.2 KBI Pin Enable Register (KBIPE) ..................................................................................123
8.3.3 KBI Edge Select Register (KBIES) ................................................................................123
Functional Description ..................................................................................................................124
8.4.1 Edge Only Sensitivity .....................................................................................................124
8.4.2 Edge and Level Sensitivity .............................................................................................124
8.4.3 KBI Pullup/Pulldown Resistors ......................................................................................125
8.4.4 KBI Initialization ............................................................................................................125
Chapter 9
5 V Analog Comparator (S08ACMPV2)
9.1
9.2
9.3
9.4
Introduction ...................................................................................................................................127
9.1.1 ACMP Configuration Information ..................................................................................127
9.1.2 ACMP/TPM Configuration Information ........................................................................127
9.1.3 Features ...........................................................................................................................129
9.1.4 Modes of Operation ........................................................................................................129
9.1.5 Block Diagram ................................................................................................................129
External Signal Description ..........................................................................................................130
Memory Map ................................................................................................................................130
9.3.1 Register Descriptions ......................................................................................................130
Functional Description ..................................................................................................................132
Chapter 10
Analog-to-Digital Converter (S08ADC12V1)
10.1 Overview .......................................................................................................................................133
10.1.1 Module Configurations ...................................................................................................133
10.1.2 Low-Power Mode Operation ..........................................................................................135
10.1.3 Features ...........................................................................................................................137
10.1.4 ADC Module Block Diagram .........................................................................................137
10.2 External Signal Description ..........................................................................................................138
10.2.1 Analog Power (VDDAD) ..................................................................................................139
10.2.2 Analog Ground (VSSAD) .................................................................................................139
10.2.3 Voltage Reference High (VREFH) ...................................................................................139
10.2.4 Voltage Reference Low (VREFL) ....................................................................................139
10.2.5 Analog Channel Inputs (ADx) ........................................................................................139
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10.3 Register Definition ........................................................................................................................139
10.3.1 Status and Control Register 1 (ADCSC1) ......................................................................139
10.3.2 Status and Control Register 2 (ADCSC2) ......................................................................141
10.3.3 Data Result High Register (ADCRH) .............................................................................141
10.3.4 Data Result Low Register (ADCRL) ..............................................................................142
10.3.5 Compare Value High Register (ADCCVH) ....................................................................142
10.3.6 Compare Value Low Register (ADCCVL) .....................................................................143
10.3.7 Configuration Register (ADCCFG) ................................................................................143
10.3.8 Pin Control 1 Register (APCTL1) ..................................................................................144
10.3.9 Pin Control 2 Register (APCTL2) ..................................................................................145
10.3.10Pin Control 3 Register (APCTL3) ..................................................................................146
10.4 Functional Description ..................................................................................................................147
10.4.1 Clock Select and Divide Control ....................................................................................147
10.4.2 Input Select and Pin Control ...........................................................................................148
10.4.3 Hardware Trigger ............................................................................................................148
10.4.4 Conversion Control .........................................................................................................148
10.4.5 Automatic Compare Function .........................................................................................151
10.4.6 MCU Wait Mode Operation ............................................................................................151
10.4.7 MCU Stop3 Mode Operation ..........................................................................................151
10.4.8 MCU Stop2 Mode Operation ..........................................................................................152
10.5 Initialization Information ..............................................................................................................152
10.5.1 ADC Module Initialization Example .............................................................................153
10.6 Application Information ................................................................................................................154
10.6.1 External Pins and Routing ..............................................................................................154
10.6.2 Sources of Error ..............................................................................................................156
Chapter 11
Inter-Integrated Circuit (S08IICV2)
11.1 Introduction ...................................................................................................................................159
11.1.1 Features ...........................................................................................................................161
11.1.2 Modes of Operation ........................................................................................................161
11.1.3 Block Diagram ................................................................................................................161
11.2 External Signal Description ..........................................................................................................162
11.2.1 SCL — Serial Clock Line ...............................................................................................162
11.2.2 SDA — Serial Data Line ................................................................................................162
11.3 Register Definition ........................................................................................................................162
11.3.1 IIC Address Register (IICA) ...........................................................................................163
11.3.2 IIC Frequency Divider Register (IICF) ..........................................................................163
11.3.3 IIC Control Register (IICC1) ..........................................................................................166
11.3.4 IIC Status Register (IICS) ...............................................................................................166
11.3.5 IIC Data I/O Register (IICD) ..........................................................................................167
11.3.6 IIC Control Register 2 (IICC2) .......................................................................................168
11.4 Functional Description ..................................................................................................................169
11.4.1 IIC Protocol .....................................................................................................................169
11.4.2 10-bit Address .................................................................................................................172
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11.4.3 General Call Address ......................................................................................................173
11.5 Resets ............................................................................................................................................173
11.6 Interrupts .......................................................................................................................................173
11.6.1 Byte Transfer Interrupt ....................................................................................................173
11.6.2 Address Detect Interrupt .................................................................................................174
11.6.3 Arbitration Lost Interrupt ................................................................................................174
11.7 Initialization/Application Information ..........................................................................................175
Chapter 12
Multi-Purpose Clock Generator (S08MCGV1)
12.1 Introduction ...................................................................................................................................177
12.1.1 Features ...........................................................................................................................179
12.1.2 Modes of Operation ........................................................................................................181
12.2 External Signal Description ..........................................................................................................181
12.3 Register Definition ........................................................................................................................182
12.3.1 MCG Control Register 1 (MCGC1) ...............................................................................182
12.3.2 MCG Control Register 2 (MCGC2) ...............................................................................183
12.3.3 MCG Trim Register (MCGTRM) ...................................................................................184
12.3.4 MCG Status and Control Register (MCGSC) .................................................................185
12.3.5 MCG Control Register 3 (MCGC3) ...............................................................................186
12.4 Functional Description ..................................................................................................................188
12.4.1 Operational Modes ..........................................................................................................188
12.4.2 Mode Switching ..............................................................................................................192
12.4.3 Bus Frequency Divider ...................................................................................................192
12.4.4 Low Power Bit Usage .....................................................................................................193
12.4.5 Internal Reference Clock ................................................................................................193
12.4.6 External Reference Clock ...............................................................................................193
12.4.7 Fixed Frequency Clock ...................................................................................................193
12.5 Initialization / Application Information ........................................................................................194
12.5.1 MCG Module Initialization Sequence ............................................................................194
12.5.2 MCG Mode Switching ....................................................................................................195
12.5.3 Calibrating the Internal Reference Clock (IRC) .............................................................206
Chapter 13
Real-Time Counter (S08RTCV1)
13.1 Introduction ...................................................................................................................................209
13.1.1 Features ...........................................................................................................................211
13.1.2 Modes of Operation ........................................................................................................211
13.1.3 Block Diagram ................................................................................................................212
13.2 External Signal Description ..........................................................................................................212
13.3 Register Definition ........................................................................................................................212
13.3.1 RTC Status and Control Register (RTCSC) ....................................................................213
13.3.2 RTC Counter Register (RTCCNT) ..................................................................................214
13.3.3 RTC Modulo Register (RTCMOD) ................................................................................214
13.4 Functional Description ..................................................................................................................214
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13.4.1 RTC Operation Example .................................................................................................215
13.5 Initialization/Application Information ..........................................................................................216
Chapter 14
Serial Communications Interface (S08SCIV4)
14.1 Introduction ...................................................................................................................................219
14.1.1 Features ...........................................................................................................................221
14.1.2 Modes of Operation ........................................................................................................221
14.1.3 Block Diagram ................................................................................................................222
14.2 Register Definition ........................................................................................................................224
14.2.1 SCI Baud Rate Registers (SCIxBDH, SCIxBDL) ..........................................................224
14.2.2 SCI Control Register 1 (SCIxC1) ...................................................................................225
14.2.3 SCI Control Register 2 (SCIxC2) ...................................................................................226
14.2.4 SCI Status Register 1 (SCIxS1) ......................................................................................227
14.2.5 SCI Status Register 2 (SCIxS2) ......................................................................................229
14.2.6 SCI Control Register 3 (SCIxC3) ...................................................................................230
14.2.7 SCI Data Register (SCIxD) .............................................................................................231
14.3 Functional Description ..................................................................................................................231
14.3.1 Baud Rate Generation .....................................................................................................231
14.3.2 Transmitter Functional Description ................................................................................232
14.3.3 Receiver Functional Description ....................................................................................233
14.3.4 Interrupts and Status Flags ..............................................................................................235
14.3.5 Additional SCI Functions ...............................................................................................236
Chapter 15
16-Bit Serial Peripheral Interface (S08SPI16V1)
15.1 Introduction ...................................................................................................................................239
15.1.1 SPI Port Configuration Information ...............................................................................239
15.1.2 Features ...........................................................................................................................242
15.1.3 Modes of Operation ........................................................................................................242
15.1.4 Block Diagrams ..............................................................................................................242
15.2 External Signal Description ..........................................................................................................244
15.2.1 SPSCK — SPI Serial Clock ............................................................................................244
15.2.2 MOSI — Master Data Out, Slave Data In ......................................................................245
15.2.3 MISO — Master Data In, Slave Data Out ......................................................................245
15.2.4 SS — Slave Select ..........................................................................................................245
15.3 Register Definition ........................................................................................................................245
15.3.1 SPI Control Register 1 (SPIxC1) ....................................................................................245
15.3.2 SPI Control Register 2 (SPIxC2) ....................................................................................246
15.3.3 SPI Baud Rate Register (SPIxBR) ..................................................................................248
15.3.4 SPI Status Register (SPIxS) ............................................................................................249
15.3.5 SPI Data Registers (SPIxDH:SPIxDL) ...........................................................................250
15.3.6 SPI Match Registers (SPIxMH:SPIxML) .......................................................................251
15.4 Functional Description ..................................................................................................................252
15.4.1 General ............................................................................................................................252
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15.4.2 Master Mode ...................................................................................................................252
15.4.3 Slave Mode .....................................................................................................................253
15.4.4 Data Transmission Length ..............................................................................................254
15.4.5 SPI Clock Formats ..........................................................................................................255
15.4.6 SPI Baud Rate Generation ..............................................................................................257
15.4.7 Special Features ..............................................................................................................258
15.4.8 Error Conditions .............................................................................................................259
15.4.9 Low Power Mode Options ..............................................................................................260
15.4.10SPI Interrupts ..................................................................................................................261
15.5 Initialization/Application Information ..........................................................................................263
15.5.1 SPI Module Initialization Example .................................................................................263
Chapter 16
Timer/Pulse-Width Modulator (S08TPMV2)
16.1 Introduction ...................................................................................................................................267
16.1.1 Features ...........................................................................................................................269
16.1.2 Modes of Operation ........................................................................................................269
16.1.3 Block Diagram ................................................................................................................270
16.2 Signal Description .........................................................................................................................272
16.2.1 Detailed Signal Descriptions ..........................................................................................272
16.3 Register Definition ........................................................................................................................276
16.3.1 TPM Status and Control Register (TPMxSC) ................................................................276
16.3.2 TPM-Counter Registers (TPMxCNTH:TPMxCNTL) ....................................................277
16.3.3 TPM Counter Modulo Registers (TPMxMODH:TPMxMODL) ....................................278
16.3.4 TPM Channel n Status and Control Register (TPMxCnSC) ..........................................279
16.3.5 TPM Channel Value Registers (TPMxCnVH:TPMxCnVL) ..........................................281
16.4 Functional Description ..................................................................................................................282
16.4.1 Counter ............................................................................................................................283
16.4.2 Channel Mode Selection .................................................................................................285
16.5 Reset Overview .............................................................................................................................288
16.5.1 General ............................................................................................................................288
16.5.2 Description of Reset Operation .......................................................................................288
16.6 Interrupts .......................................................................................................................................288
16.6.1 General ............................................................................................................................288
16.6.2 Description of Interrupt Operation .................................................................................289
Chapter 17
Universal Serial Bus Device Controller (S08USBV1)
17.1 Introduction ...................................................................................................................................295
17.1.1 Clocking Requirements ...................................................................................................295
17.1.2 Current Consumption in USB Suspend ..........................................................................295
17.1.3 3.3 V Regulator ...............................................................................................................295
17.1.4 Features ...........................................................................................................................298
17.1.5 Modes of Operation ........................................................................................................298
17.1.6 Block Diagram ................................................................................................................299
MC9S08JM16 Series Data Sheet, Rev. 2
16
Freescale Semiconductor
17.2 External Signal Description ..........................................................................................................300
17.2.1 USBDP ............................................................................................................................300
17.2.2 USBDN ...........................................................................................................................300
17.2.3 VUSB33 ............................................................................................................................................................. 300
17.3 Register Definition ........................................................................................................................300
17.3.1 USB Control Register 0 (USBCTL0) .............................................................................301
17.3.2 Peripheral ID Register (PERID) .....................................................................................301
17.3.3 Peripheral ID Complement Register (IDCOMP) ............................................................302
17.3.4 Peripheral Revision Register (REV) ...............................................................................302
17.3.5 Interrupt Status Register (INTSTAT) ..............................................................................303
17.3.6 Interrupt Enable Register (INTENB) ..............................................................................304
17.3.7 Error Interrupt Status Register (ERRSTAT) ...................................................................305
17.3.8 Error Interrupt Enable Register (ERRENB) ...................................................................306
17.3.9 Status Register (STAT) ....................................................................................................307
17.3.10Control Register (CTL) ...................................................................................................308
17.3.11Address Register (ADDR) ..............................................................................................309
17.3.12Frame Number Register (FRMNUML, FRMNUMH) ...................................................309
17.3.13Endpoint Control Register (EPCTLn, n=0-6) .................................................................310
17.4 Functional Description ..................................................................................................................311
17.4.1 Block Descriptions ..........................................................................................................311
17.4.2 Buffer Descriptor Table (BDT) .......................................................................................316
17.4.3 USB Transactions ...........................................................................................................319
17.4.4 USB Packet Processing ...................................................................................................321
17.4.5 Start of Frame Processing ...............................................................................................322
17.4.6 Suspend/Resume .............................................................................................................323
17.4.7 Resets ..............................................................................................................................324
17.4.8 Interrupts .........................................................................................................................325
Chapter 18
Development Support
18.1 Introduction ...................................................................................................................................327
18.1.1 Forcing Active Background ............................................................................................327
18.1.2 Features ...........................................................................................................................328
18.2 Background Debug Controller (BDC) ..........................................................................................328
18.2.1 BKGD Pin Description ...................................................................................................329
18.2.2 Communication Details ..................................................................................................330
18.2.3 BDC Commands .............................................................................................................334
18.2.4 BDC Hardware Breakpoint .............................................................................................336
18.3 On-Chip Debug System (DBG) ....................................................................................................337
18.3.1 Comparators A and B .....................................................................................................337
18.3.2 Bus Capture Information and FIFO Operation ...............................................................337
18.3.3 Change-of-Flow Information ..........................................................................................338
18.3.4 Tag vs. Force Breakpoints and Triggers .........................................................................338
18.3.5 Trigger Modes .................................................................................................................339
18.3.6 Hardware Breakpoints ....................................................................................................341
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
17
18.4 Register Definition ........................................................................................................................341
18.4.1 BDC Registers and Control Bits .....................................................................................341
18.4.2 System Background Debug Force Reset Register (SBDFR) ..........................................343
18.4.3 DBG Registers and Control Bits .....................................................................................344
Appendix A
Electrical Characteristics
A.1
A.2
A.3
A.4
A.5
A.6
A.7
A.8
A.9
A.10
A.11
A.12
Introduction ....................................................................................................................................349
Parameter Classification.................................................................................................................349
Absolute Maximum Ratings...........................................................................................................349
Thermal Characteristics..................................................................................................................350
ESD Protection and Latch-up Immunity........................................................................................351
DC Characteristics..........................................................................................................................352
Supply Current Characteristics.......................................................................................................356
Analog Comparator (ACMP) Electricals .......................................................................................357
ADC Characteristics.......................................................................................................................357
External Oscillator (XOSC) Characteristics ..................................................................................361
MCG Specifications .......................................................................................................................362
AC Characteristics..........................................................................................................................363
A.12.1 Control Timing ................................................................................................................363
A.12.2 Timer/PWM (TPM) Module Timing ...............................................................................364
A.12.3 SPI Characteristics ...........................................................................................................365
A.13 Flash Specifications........................................................................................................................369
A.14 USB Electricals ..............................................................................................................................369
18.5 EMC Performance .........................................................................................................................370
18.5.1 Radiated Emissions .........................................................................................................370
Appendix B
Ordering Information and Mechanical Drawings
B.1 Ordering Information .....................................................................................................................373
B.2 Orderable Part Numbering System ................................................................................................373
B.3 Mechanical Drawings.....................................................................................................................373
MC9S08JM16 Series Data Sheet, Rev. 2
18
Freescale Semiconductor
Chapter 1
Device Overview
1.1
Introduction
MC9S08JM16 series MCUs 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.
Table 1-1 summarizes the peripheral availability per package type for the devices available in the
MC9S08JM16 series.
Table 1-1. Devices in the MC9S08JM16 Series
Device
Feature
MC9S08JM16
Package
48-pin
44-pin
MC9S08JM8
32-pin
48-pin
44-pin
Flash
16,384
8,192
RAM
1024
1024
USB RAM
256
256
ACMP
yes
yes
ADC
8-ch
8-ch
IIC
4-ch
8-ch
8-ch
yes
IRQ
7
7
SCI1
yes
5
7
7
yes
SCI2
yes
SPI1
SPI2
no
yes
4-ch
yes
no
yes
no
4-ch
5
yes
yes
TPM1
4-ch
yes
yes
KBI
32-pin
2-ch
yes
4-ch
no
4-ch
TPM2
2-ch
2-ch
USB
yes
yes
2-ch
I/O pins
37
33
21
37
33
21
Package types
48 QFN
44 LQFP
32 LQFP
48 QFN
44 LQFP
32 LQFP
1.2
MCU Block Diagram
The block diagram in Figure 1-1 shows the structure of the MC9S08JM16 series MCU.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
19
Chapter 1 Device Overview
CPU
HCS08 SYSTEM CONTROL
RESETS AND INTERRUPTS
MODES OF OPERATION
POWER MANAGEMENT
FULL SPEED
USB
USB ENDPOINT TRANSCEIVER
RAM
8-/16-BIT
SERIAL PERIPHERAL
INTERFACE MODULE (SPI2)
SERIAL COMMUNICATIONS
INTERFACE MODULE (SCI2)
COP
IRQ
LVD
IIC MODULE (IIC)
VDDAD
8-CHANNEL, 12-BIT
ANALOG-TO-DIGITAL
CONVERTER (ADC)
VSSAD
VREFL
VREFH
USER FLASH (IN BYTES)
MC9S08JM16 = 16,384
MC9S08JM8 = 8,192
PORT B
BDC
SS2
SPSCK2
MOSI2
MISO2
RxD2
PORT C
IRQ/TPMCLK
USB SIE
TxD2
SDA
SCL
ACMP–
ANALOG COMPARATOR
(ACMP)
ACMP+
8-/16-BIT
SERIAL PERIPHERAL
INTERFACE MODULE (SPI1)
SPSCK1
ACMPO
VDD
VSS
VUSB33
LOW-POWER OSCILLATOR
SYSTEM
VOLTAGE
REGULATOR
SERIAL COMMUNICATIONS
INTERFACE MODULE (SCI1)
2-CHANNEL TIMER/PWM
MODULE (TPM2)
REAL-TIME COUNTER
(RTC)
7-BIT KEYBOARD
INTERRUPT MODULE (KBI)
PTD1/ADP9/ACMP–
PTD0/ADP8/ACMP+
PTE5/MOSI1
MISO1
TPMCLK
TPM1CH1
PTE4/MISO1
TPM1CH0
TPM1CHx 2
PTE3/TPM1CH1
PTE2/TPM1CH0
RxD1
TxD1
PTE1/RxD1
PTE0/TxD1
TPMCLK
TPM2CH1
TPM2CH0
PTF6
PTF5/TPM2CH1
PTF4/TPM2CH0
KBIPx
USB 3.3 V VOLTAGE REGULATOR
PTD7
PTD2/KBIP2/ACMPO
PTE6/SPSCK1
MOSI1
PORT E
MODULE (TPM1)
PTC5/RxD2
PTC4
PTC3/TxD2
PTC2
PTE7/SS1
KBIPx
PORT F
VSSOSC
4-CHANNEL TIMER/PWM
PTB5/KBIP5/ADP5
PTB4/KBIP4/ADP4
PTB3/SS2/ADP3
PTB2/SPSCK2/ADP2
PTB1/MOSI2/ADP1
PTB0/MISO2/ADP0
2
3
PTF1/TPM1CH3
PTF0/TPM1CH2
4
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 must not be driven above VDD.
4. Pin contains integrated pullup device.
5. When pin functions as KBI (KBIPEn = 1) and associated pin is configured to enable the
pullup device, KBEDGn can be used to reconfigure the pullup as a pulldown device.
PTG5/EXTAL
PORT G
MULTI-PURPOSE CLOCK
GENERATOR (MCG)
PTA5, PTA0
6
SS1
USER RAM (IN BYTES)
1024
2
PTC1/SDA
PTC0/SCL
PORT D
RESET
PORT A
HCS08 CORE
BKGD/MS
USBDP
USBDN
ON-CHIP ICE AND
DEBUG MODULE (DBG)
PTG4/XTAL
PTG3/KBIP7
PTG2/KBIP6
PTG1/KBIP1
PTG0/KBIP0
Figure 1-1. MC9S08JM16 Series Block Diagram
MC9S08JM16 Series Data Sheet, Rev. 2
20
Freescale Semiconductor
Chapter 1 Device Overview
Table 1-2 lists the functional versions of the on-chip modules.
Table 1-2. Versions of On-Chip Modules
Module
1.3
Version
Analog Comparator
(ACMP)
2
Analog-to-Digital Converter
(ADC)
1
Central Processing Unit
(CPU)
2
IIC Module
(IIC)
2
Keyboard Interrupt
(KBI)
2
Multi-Purpose Clock Generator
(MCG)
1
Real-Time Counter
(RTC)
1
Serial Communications Interface
(SCI)
4
8-/16-bit Serial Peripheral Interface
(SPI16)
1
Timer Pulse-Width Modulator
(TPM)
3
Universal Serial Bus
(USB)
1
Debug Module
(DBG)
2
System Clock Distribution
Figure 1-2 shows a simplified clock connection diagram. Some modules in the MCU have selectable clock
inputs as shown. The clock inputs to the modules indicate the clock(s) that are used to drive the module
functions. All memory mapped registers associated with the modules are clocked with BUSCLK.
TPMCLK
1 kHz
LPO
LPO clock
RTC
COP
TPM1
TPM2
IIC
SCI1
SCI2
SPI1
RAM
FLASH3
SPI1
MCGERCLK
MCGIRCLK
MCG
MCGFFCLK
÷2
MCGOUT
÷2
FFCLK1
BUSCLK
MCGLCLK
XOSC
USB
RAM
EXTAL
USB
CPU
BDC
ADC2
XTAL
1. The FFCLK is internally synchronized to the bus clock and must not exceed one half of the bus clock frequency.
2. ADC has min. and max. frequency requirements. See Chapter 10, “Analog-to-Digital Converter (S08ADC12V1),” and Appendix A, “Electrical
Characteristics,” for details.
3. Flash has frequency requirements for program and erase operation. See Appendix A, “Electrical Characteristics,” for details.
Figure 1-2. System Clock Distribution Diagram
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
21
Chapter 1 Device Overview
The MCG supplies the following clock sources:
• MCGOUT — This clock source is used as the CPU, USB RAM and USB module clock, and is
divided by two to generate the peripheral bus clock (BUSCLK). Control bits in the MCG control
registers determine which of the three clock sources is connected:
— Internal reference clock
— External reference clock
— Frequency-locked loop (FLL) or phase-locked loop (PLL) output
See Chapter 12, “Multi-Purpose Clock Generator (S08MCGV1),” for details on configuring the
MCGOUT clock.
• MCGLCLK — This clock source is derived from the digitally controlled oscillator (DCO) of the
MCG. Development tools can select this internal self-clocked source to speed up BDC
communications in systems where the bus clock is slow.
• MCGIRCLK — This is the internal reference clock and can be selected as the real-time counter
(RTC) clock source. Chapter 12, “Multi-Purpose Clock Generator (S08MCGV1),” explains the
MCGIRCLK in more detail. See Chapter 13, “Real-Time Counter (S08RTCV1),” for more
information regarding the use of MCGIRCLK.
• MCGERCLK — This is the external reference clock and can be selected as the clock source of
RTC and ADC module. Section 12.4.6, “External Reference Clock,” explains the MCGERCLK in
more detail. See Chapter 13, “Real-Time Counter (S08RTCV1),” and Chapter 10,
“Analog-to-Digital Converter (S08ADC12V1),” for more information regarding the use of
MCGERCLK with these modules.
• MCGFFCLK — This clock source is divided by two to generate FFCLK after being synchronized
to the BUSCLK. It can be selected as clock source for the TPM modules. The frequency of the
MCGFFCLK is determined by the settings of the MCG. See the Section 12.4.7, “Fixed Frequency
Clock,” for details.
• LPO clock— This clock is generated from an internal low power oscillator that is completely
independent of the MCG module. The LPO clock can be selected as the clock source to the RTC
or COP modules. See Chapter 13, “Real-Time Counter (S08RTCV1),” and Section 5.4, “Computer
Operating Properly (COP) Watchdog,” for details on using the LPO clock with these modules.
• TPMCLK — TPMCLK is the optional external clock source for the TPM modules. The TPMCLK
must be limited to 1/4th the frequency of the BUSCLK for synchronization. See Chapter 16,
“Timer/Pulse-Width Modulator (S08TPMV2),” for more details.
MC9S08JM16 Series Data Sheet, Rev. 2
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.
2.2
Device Pin Assignment
PTG2/KBIP6
37
48
47
PTC4 1
PTD7
PTG3/KBIP7
BKGD/MS
PTG4/XTAL
PTG5/EXTAL
VSSOSC
PTC0/SCL
PTC1/SDA
PTC2
PTC3/TxD2
PTC5/RxD2
Figure 2-1 shows the 48-pin QFN pin assignments for the MC9S08JM16. See Table 2-1 for pin
availability by package pin count.
46
45
44
43
42
41
40
39
38
36 PTD2/KBIP2/ACMPO
IRQ/TPMCLK
2
35
VSSAD/VREFL
RESET
3
34
VDDAD/VREFH
PTF0/TPM1CH2
4
33
PTD1/ADP9/ACMP–
PTF1/TPM1CH3
5
32
PTD0/ADP8/ACMP+
PTF4/TPM2CH0
6
31
PTB5/KBIP5/ADP5
PTF5/TPM2CH1
7
30
PTB4/KBIP4/ADP4
PTF6
8
29
PTB3/SS2/ADP3
PTE0/TxD1
9
28
PTB2/SPSCK2/ADP2
PTE1/RxD1
10
27
PTB1/MOSI2/ADP1
PTE2/TPM1CH0
11
26
PTB0/MISO2/ADP0
48-Pin QFN
25 PTA5
PTE3/TPM1CH1 12
14
15
16
17
18
19
20
21
22
23
24
PTA0
PTG1/KBIP1
PTG0/KBIP0
VUSB33
USBDP
USBDN
VSS
VDD
PTE7/SS1
PTE6/SPSCK1
PTE5/MOSI1
PTE4/MISO1
13
Figure 2-1. MC9S08JM16 Series in 48-Pin QFN Package
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
23
Chapter 2 Pins and Connections
PTC2
PTC1/SDA
PTC0/SCL
VSSOSC
PTG5/EXTAL
PTG4/XTAL
BKGD/MS
PTG3/KBIP7
43
42
41
40
39
38
37
36
35
34
44
PTC4 1
PTG2/KBIP6
PTC3/TxD2
PTC5/RxD2
Figure 2-2 shows the 44-pin LQFP pin assignments for the MC9S08JM16 devices. See Table 2-1 for pin
availability by package pin count.
33 PTD2/KBIP2/ACMPO
IRQ/TPMCLK
2
32
VSSAD/VREFL
RESET
3
31
VDDAD/VREFH
PTF0/TPM1CH2
4
30
PTD1/ADP9/ACMP–
PTF1/TPM1CH3
5
29
PTD0/ADP8/ACMP+
28
PTB5/KBIP5/ADP5
44-Pin LQFP
PTF4/TPM2CH0
6
PTF5/TPM2CH1
7
27
PTB4/KBIP4/ADP4
PTE0/TxD1
8
26
PTB3/SS2/ADP3
PTE1/RxD1
9
25
PTB2/SPSCK2/ADP2
PTE2/TPM1CH0
10
24
PTB1/MOSI2/ADP1
PTE3/TPM1CH1 11
13
14
15
16
17
18
19
20
PTG0/KBIP0
VUSB33
USBDP
USBDN
VSS
VDD
PTE7/SS1
PTE6/SPSCK1
PTE5/MOSI1
PTG1/KBIP1
22
12
PTE4/MISO1
23 PTB0/MISO2/ADP0
21
Figure 2-2. MC9S08JM16 Series in 44-Pin LQFP Package
Figure 2-3 shows the 32-pin LQFP pin assignments for the MC9S08JM16 devices. See Table 2-1 for pin
availability by package pin count.
MC9S08JM16 Series Data Sheet, Rev. 2
24
Freescale Semiconductor
PTC0/SCL
VSSOSC
PTG5/EXTAL
PTG4/XTAL
BKGD/MS
PTG3/KBIP7
PTG2/KBIP6
PTC1/SDA
Chapter 2 Pins and Connections
31
30
29
28
27
26
25
32
IRQ/TPMCLK 1
24 PTD2/KBIP2/ACMPO
RESET
2
23
VSSAD/VREFL
PTF4/TPM2CH0
3
22
VDDAD/VREFH
PTF5/TPM2CH1
4
21
PTD1/ADP9/ACMP–
PTE0/TxD1
5
20
PTD0/ADP8/ACMP+
PTE1/RxD1
6
19
PTB5/KBIP5/ADP5
PTE2/TPM1CH0
7
18
PTB4/KBIP4/ADP4
PTE3/TPM1CH1
8
17
VUSB33
10
11
12
13
14
15
16
PTE5/MOSI1
PTE6/SPSCK1
PTE7/SS1
VDD
VSS
USBDN
USBPDP
32-Pin LQFP
PTE4/MISO1
9
Figure 2-3. MC9S08JM16 Series in 32-Pin LQFP Package
2.3
Recommended System Connections
Figure 2-4 shows pin connections that are common to almost all MC9S08JM16 series application systems.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
25
Chapter 2 Pins and Connections
VREFH MC9S08JM16
VDDAD
CBYAD
0.1 μF
VSSAD
VREFL
VDD
VDD
SYSTEM
POWER
+
5V
CBLK +
10 μF
CBY
0.1 μF
PORT
B
VSS
NOTE 1
PORT
A
PTA0, PTA5
PTB0/MISO2/ADP0
PTB1/MOSI2/ADP1
PTB2/SPSCK2/ADP2
PTB3/SS2/ADP3
PTB4/KBIP4/ADP4
PTB5/KBIP5/ADP5
RF
C1
C2
X1
XTAL
RS
PORT
C
VSSOSC
EXTAL
BACKGROUND HEADER
VDD
BKGD/MS
PORT
D
VDD
4.7 kΩ–10 kΩ
RESET
4.7 kΩ–
10 kΩ
IRQ/TPMCLK
IRQ
0.1 μF
PORT
E
3.3-V Reference
+
4.7 μF
0.47 μF
2
1
3
4
USBDN
VBus
APPLICATION
SYSTEM
PTE0/TxD1
PTE1/RxD1
PTE2/TPM1CH0
PTE3/TPM1CH1
PTE4/MISO1
PTE5/MOSI1
PTE6/SPSCK1
PTE7/SS1
PTF0/TPM1CH2
PTF1/TPM1CH3
VUSB33
PORT
F
USB SERIES-B CONNECTOR
I/O AND
PTD0/ADP8/ACMP+
PTD1/ADP9/ACMP– PERIPHERAL
PTD2/KBIP2/ACMPO
INTERFACE TO
PTD7
0.1 μF VDD
OPTIONAL
MANUAL
RESET
PTC0/SCL
PTC1/SDA
PTC2
PTC3/TxD2
PTC4
PTC5/RxD2
VUSB33
RPUDP
PORT
G
USBDP
PTF4/TPM2CH0
PTF5/TPM2CH1
PTF6
PTG0/KBIP0
PTG1/KBIP1
PTG2/KBIP6
PTG3/KBIP7
PTG4/XTAL
PTG5/EXTAL
NOTES:
1. External crystal circuity is not required if using the MCG internal clock option. For USB operation, an external crystal is required.
2. XTAL and EXTAL are the same pins as PTG4 and PTG5, respectively.
3. RC filters on RESET and IRQ are recommended for EMC-sensitive applications.
4. RPUDP is shown for full-speed USB only. The diagram shows a configuration where the on-chip regulator and RPUDP are enabled.
The voltage regulator output is used for RPUDP. RPUDP can optionally be disabled if using an external pullup resistor on USBDP
5. VBUS is a 5.0 V supply from upstream port that can be used for USB operation.
6. USBDP and USBDN are powered by the 3.3 V regulator.
Figure 2-4. Basic System Connections
MC9S08JM16 Series Data Sheet, Rev. 2
26
Freescale Semiconductor
Chapter 2 Pins and Connections
2.3.1
Power (VDD, VSS, VSSOSC, VDDAD, VSSAD, VUSB33)
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 is 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 as practical to the paired VDD and
VSS power pins to suppress high-frequency noise. The MC9S08JM16 has a VSSOSC pin. This pin must 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 must be located as near to the analog power pins as
practical to suppress high-frequency noise.
VUSB33 is connected to the internal USB 3.3 V regulator. VUSB33 maintains an output voltage of 3.3 V
and only can source enough current for internal USB transceiver and USB pullup resistor. Two separate
capacitors (4.7 F bulk electrolytic stability capacitor and 0.47 F ceramic bypass capacitors) must be
connected across this pin to ground to decrease the output ripple of this voltage regulator when it is
enabled.
2.3.2
Oscillator (XTAL, EXTAL)
Immediately after reset, the MCU uses an internally generated clock provided by the multi-purpose clock
generator (MCG) module. For more information on the MCG, see Chapter 12, “Multi-Purpose Clock
Generator (S08MCGV1).”
The oscillator (XOSC) in this MCU is a Pierce oscillator that can accommodate a crystal or ceramic
resonator. Rather than a crystal or ceramic resonator, an external oscillator can be connected to the EXTAL
input pin.
RS (when used) and RF must 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 must
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; 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 selecting 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).
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
27
Chapter 2 Pins and Connections
2.3.3
RESET Pin
RESET is a dedicated pin with a built-in pullup device. 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
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 source or from an internal source, the RESET
pin is driven low for approximately 66 bus cycles and released. The reset circuity 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)
When 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 must 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 can be used for TPMCLK.
In EMC-sensitive applications, an external RC filter is recommended on the IRQ pin. See Figure 2-4 for
an example.
MC9S08JM16 Series Data Sheet, Rev. 2
28
Freescale Semiconductor
Chapter 2 Pins and Connections
2.3.7
USB Data Pins (USBDP, USBDN)
The USBDP (D+) and USBDN (D–) pins are the analog input/output lines to/from full-speed internal
USB transceiver. An optional internal pullup resistor for the USBDP pin, RPUDP, is available.
2.3.8
General-Purpose I/O and Peripheral Ports
The MC9S08JM16 series of MCUs support up to 37 general-purpose I/O pins, which are shared with
on-chip peripheral functions (timers, serial I/O, ADC, keyboard interrupts, etc.).
When a port pin is configured as a general-purpose output or a peripheral uses the port pin as an output,
software can select one of two drive strengths and enable or disable slew rate control. When a port pin is
configured as a general-purpose input or a peripheral uses the port pin as an input, software can enable a
pullup device.
For information about controlling these pins as general-purpose I/O pins, see the Chapter 6, “Parallel
Input/Output.” For information about how and when on-chip peripheral systems use these pins, see the
appropriate module chapter.
Immediately after reset, all pins are configured as high-impedance general-purpose inputs with internal
pullup devices disabled.
NOTE
When an alternative function is first enabled, it is possible to get a spurious
edge to the module, user software must 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.
Disable all modules that share a pin before enabling another module.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
29
Chapter 2 Pins and Connections
Table 2-1. Pin Availability by Package Pin-Count
Pin Number
Lowest <--Priority--> Highest
Pin Number
Lowest <--Priority--> Highest
48
44
32
Port Pin
25
—
—
PTA5
TPMCLK
26
23
—
PTB0
MISO2
ADP0
RESET
27
24
—
PTB1
MOSI2
ADP1
TPM1CH2
28
25
—
PTB2
SPSCK2
ADP2
PTF1
TPM1CH3
29
26
—
PTB3
SS2
ADP3
3
PTF4
TPM2CH0
30
27
18
PTB4
KBIP4
ADP4
7
4
PTF5
TPM2CH1
31
28
19
PTB5
KBIP5
ADP5
8
—
—
PTF6
32
29
20
PTD0
ADP8
ACMP+
9
8
5
PTE0
TxD1
33
30
21
PTD1
ADP9
ACMP–
10
9
6
PTE1
RxD1
34
31
22
11
10
7
PTE2
TPM1CH0
12
11
8
PTE3
TPM1CH1
13
12
9
PTE4
MISO1
14
13
10
PTE5
MOSI1
36
33
24
PTD2
15
14
11
PTE6
SPSCK1
37
—
—
PTD7
16
15
12
PTE7
SS1
38
34
25
PTG2
KBIP6
17
16
13
VDD
39
35
26
PTG3
KBIP7
18
17
14
VSS
40
36
27
19
18
15
USBDN
41
37
28
PTG4
XTAL
20
19
16
USBDP
42
38
29
PTG5
EXTAL
21
20
17
VUSB33
43
39
30
22
21
—
PTG0
KBIP0
44
40
31
PTC0
SCL
23
22
—
PTG1
KBIP1
45
41
32
PTC1
SDA
24
—
—
PTA0
46
42
—
PTC2
47
43
—
PTC3
TxD2
48
44
—
PTC5
RxD2
48
44
32
Port Pin
1
1
—
PTC4
2
2
1
3
3
2
4
4
—
PTF0
5
5
—
6
6
7
Alt1
IRQ
Alt2
Alt1
Alt2
VDDAD
VREFH
35
32
VREFL
23
VSSAD
KBIP2
BKGD
ACMPO
MS
VSSOSC
MC9S08JM16 Series Data Sheet, Rev. 2
30
Freescale Semiconductor
Chapter 3
Modes of Operation
3.1
Introduction
The operating modes of the MC9S08JM16 series are described in this chapter. Entry into each mode, exit
from each mode, and functionality while in each mode are described.
3.2
•
•
•
3.3
Features
Active background mode for code development
Wait mode:
— CPU halts operation to conserve power
— System clocks continue to run
— Full voltage regulation is maintained
Stop modes: CPU and bus clocks stopped
— Stop2: Partial power down of internal circuits; RAM and USB RAM contents retained
— Stop3: All internal circuits powered for fast recovery; RAM, USB RAM, and register contents
are retained
Run Mode
Run is the normal operating mode for the MC9S08JM16 series. This mode is selected upon the MCU
exiting reset if the BKGD/MS pin is high. In this mode, the CPU executes code from internal memory with
execution beginning at the address fetched from memory at 0xFFFE:0xFFFF 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 in-circuit emulator (ICE) debug module (DBG),
provides 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 during POR or immediately after issuing a background debug
force reset (see Section 5.7.3, “System Background Debug Force Reset Register (SBDFR)”)
• 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
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
31
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 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 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 MC9S08JM16
series are shipped from the Freescale 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 the Chapter 18, “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 the condition code register (CCR) is cleared
when the CPU enters wait mode, enabling interrupts. When an interrupt request occurs, the CPU exits wait
mode and resumes processing, beginning with the stacking operations leading to the interrupt service
routine.
While the MCU is in wait mode, background debug commands can be used on the following restrictions.
• Only the BACKGROUND command and memory-access-with-status commands are available
while 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 stop or wait mode.
• The BACKGROUND command can be used to wake the MCU from wait mode and enter active
background mode.
MC9S08JM16 Series Data Sheet, Rev. 2
32
Freescale Semiconductor
Chapter 3 Modes of Operation
3.6
Stop Modes
One of two stop modes is entered upon execution of a STOP instruction when STOPE in SOPT1 is set. In
any stop mode, the bus and CPU clocks are halted. The MCG module can be configured to leave the
reference clocks running. See Chapter 12, “Multi-Purpose Clock Generator (S08MCGV1),” for more
information.
HCS08 devises that are designed for low-voltage operation (1.8 to 3.6 V) support stop1 mode. The
MC9S08JM16 series of MCUs do not support stop1 mode.
Table 3-1 shows all of the control bits that affect stop mode selection and the mode selected under various
conditions. The selected mode is entered following the execution of a STOP instruction.
Table 3-1. Stop Mode Selection
STOPE
ENBDM 1
0
x
x
x
Stop modes disabled; illegal opcode reset if STOP
instruction executed
1
1
x
x
Stop3 with BDM enabled 2
1
0
Both bits must be 1
x
Stop3 with voltage regulator active
1
0
Either bit a 0
0
Stop3
1
0
Either bit a 0
1
Stop2
LVDE
LVDSE
PPDC
Stop Mode
1
ENBDM is located in the BDCSCR which is only accessible through BDC commands, see Section 18.4.1.1,
“BDC Status and Control Register (BDCSCR).”
2
When in stop3 mode with BDM enabled, The SIDD will be near RIDD levels because internal clocks are
enabled.
3.6.1
Stop3 Mode
Stop3 mode is entered by executing a STOP instruction under the conditions 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
clock (RTC) interrupt, the USB resume interrupt, LVD, ADC, IRQ, KBI, SCI or the ACMP.
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.
3.6.1.1
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 (LVDE and LVDSE bits in SPMSC1 both set) at the time
the CPU executes a STOP instruction, 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 enter stop3 instead.
For the ADC to operate the LVD must be left enabled when entering stop3.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
33
Chapter 3 Modes of Operation
For the ACMP to operate when ACGBS in ACMPSC is set, the LVD must be left enabled when entering
stop3.
For the XOSC to operate with an external reference when RANGE in MCGC2 is set, the LVD must be left
enabled when entering stop3.
3.6.1.2
Active BDM Enabled in Stop Mode
Entry into the active background mode from run mode is enabled if ENBDM in BDCSCR is set. This
register is described in Chapter 18, “Development Support.” 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. Because of this, background debug communication remains 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 enter stop3 instead.
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.
3.6.2
Stop2 Mode
Stop2 mode is entered by executing a STOP instruction under the conditions as shown in Table 3-1. Most
of the internal circuitry of the MCU is powered off in stop2, with the exception of the RAM. Upon entering
stop2, all I/O pin control signals are latched so that the pins retain their states during stop2.
Exit from stop2 is performed by asserting either wake-up pin: RESET or IRQ.
NOTE
IRQ/TPMCLK always functions as an active-low wakeup input when the
MCU is in stop2, regardless of how the pin is configured before entering
stop2. The pullup on this pin is always disabled in stop2. This pin must be
driven or pulled high externally while in stop2 mode.
In addition, the RTC interrupt can wake the MCU from stop2, if enabled.
Upon wake-up from stop2 mode, the MCU starts up as from a power-on reset (POR):
• All module control and status registers are reset
• The LVD reset function is enabled and the MCU remains in the reset state if VDD is below the LVD
trip point (low trip point selected due to POR)
• The CPU takes the reset vector
In addition to the above, upon waking up from stop2, the PPDF bit in SPMSC2 is set. This flag is 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 1 is written to PPDACK in SPMSC2.
MC9S08JM16 Series Data Sheet, Rev. 2
34
Freescale Semiconductor
Chapter 3 Modes of Operation
To maintain I/O states for pins configured as general-purpose I/O before entering stop2, 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 pins will switch to their reset states when PPDACK is written.
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.
3.6.3
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 3.6.2, “Stop2
Mode,” and Section 3.6.1, “Stop3 Mode,” for specific information on system behavior in stop modes.
Table 3-2. Stop Mode Behavior
Mode
Peripheral
Stop2
Stop3
CPU
Off
Standby
RAM
Standby
Standby
Flash
Off
Standby
Parallel Port Registers
Off
Standby
ADC
Off
Optionally On1
ACMP
Off
Optionally On2
MCG
Off
Optionally On3
IIC
Off
RTC
Optionally
Standby
On4
Optionally On4
SCI
Off
Standby
SPI
Off
Standby
TPM
Off
Standby
System Voltage Regulator
Off
Standby
XOSC
Off
Optionally On5
States Held
States Held
USB (SIE and Transceiver)
Off
Optionally On6
USB 3.3 V Regulator
Off
Standby
Standby
Standby
I/O Pins
USB RAM
1
Requires the asynchronous ADC clock and LVD to be enabled, else in standby.
If ACGBS in ACMPSC is set, LVD must be enabled, else in standby.
3 IRCLKEN and IREFSTEN set in MCGC1, else in standby.
4 RTCPS[3:0] in RTCSC does not equal to 0 before entering stop, else off.
2
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
35
Chapter 3 Modes of Operation
5
ERCLKEN and EREFSTEN set in MCGC2, else in standby. For high frequency range
(RANGE in MCGC2 set), it also requires the LVD to be enabled in stop3.
6
USBEN in CTL is set and USBPHYEN in USBCTL0 is set, else off.
MC9S08JM16 Series Data Sheet, Rev. 2
36
Freescale Semiconductor
Chapter 4
Memory
4.1
MC9S08JM16 Series Memory Map
Figure 4-1 shows the memory map for the MC9S08JM16 series. On-chip memory in the MC9S08JM16
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 (0x0000 through 0x00AF)
• High-page registers (0x1800 through 0x185F)
• Nonvolatile registers (0xFFB0 through 0xFFBF)
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
37
Chapter 4 Memory
MC9S08JM16
MC9S08JM8
0x0000
0x0000
Direct Page Registers
0x00AF
0x00B0
Direct Page Registers
0x00AF
0x00B0
RAM
1,024 Bytes
0x04AF
0x04B0
RAM
1,024 Bytes
0x04AF
0x04B0
Unimplemented
Unimplemented
0x08AF
0x08B0
0x08AF
0x08B0
Unimplemented
Unimplemented
0x17FF
0x1800
0x17FF
0x1800
High Page Registers
0x185F
0x1860
High Page Registers
0x185F
0x1860
USB RAM — 256 BYTES
0x195F
0x1960
USB RAM — 256 BYTES
0x195F
0x1960
Unimplemented
Unimplemented
0xBFFF
0xC000
Flash
16,384 bytes
0xFFFF
0xDFFF
0xE000
Flash
8,192 bytes
0xFFFF
Figure 4-1. MC9S08JM16 Series Memory Map
MC9S08JM16 Series Data Sheet, Rev. 2
38
Freescale Semiconductor
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 MC9S08JM16 series. 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)
Vector
0xFFC0:FFC1
to
0xFFC2:FFC3
Unused Vector Space
0xFFC4:FFC5
RTC
Vrtc
0xFFC6:FFC7
IIC
Viic
0xFFC8:FFC9
ACMP
Vacmp
0xFFCA:FFCB
ADC Conversion
Vadc
0xFFCC:FFCD
KBI
Vkeyboard
0xFFCE:FFCF
SCI2 Transmit
Vsci2tx
0xFFD0:FFD1
SCI2 Receive
Vsci2rx
0xFFD2:FFD3
SCI2 Error
Vsci2err
0xFFD4:FFD5
SCI1 Transmit
Vsci1tx
0xFFD6:FFD7
SCI1 Receive
Vsci1rx
0xFFD8:FFD9
SCI1 Error
Vsci1err
0xFFDA:FFDB
TPM2 Overflow
Vtpm2ovf
0xFFDC:FFDD
TPM2 Channel 1
Vtpm2ch1
0xFFDE:FFDF
TPM2 Channel 0
Vtpm2ch0
0xFFE0:FFE1
TPM1 Overflow
Vtpm1ovf
0xFFE2:FFE3
Reserved
reserved
0xFFE4:FFE5
Reserved
reserved
0xFFE6:FFE7
TPM1 Channel 3
Vtpm1ch3
0xFFE8:FFE9
TPM1 Channel 2
Vtpm1ch2
0xFFEA:FFEB
TPM1 Channel 1
Vtpm1ch1
0xFFEC:FFED
TPM1 Channel 0
Vtpm1ch0
0xFFEE:FFEF
Reserved
reserved
0xFFF0:FFF1
USB Status
Vusb
0xFFF2:FFF3
SPI2
Vspi2
0xFFF4:FFF5
SPI1
Vspi1
Vector Name
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
39
Chapter 4 Memory
Table 4-1. Reset and Interrupt Vectors (continued)
4.2
Address
(High/Low)
Vector
Vector Name
0xFFF6:FFF7
MCG Loss of Lock
Vlol
0xFFF8:FFF9
Low Voltage Detect
Vlvd
0xFFFA:FFFB
IRQ
Virq
0xFFFC:FFFD
SWI
Vswi
0xFFFE:FFFF
Reset
Vreset
Register Addresses and Bit Assignments
The registers in the MC9S08JM16 series are divided into these three groups:
• Direct-page registers are located in the first 176 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 0x1800 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
0xFFB0–0xFFBF.
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 more efficient direct addressing mode, which requires only
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.
MC9S08JM16 Series Data Sheet, Rev. 2
40
Freescale Semiconductor
Chapter 4 Memory
Table 4-2. Direct-Page Register Summary (Sheet 1 of 4)
Address
Register
Name
Bit 7
6
5
4
3
2
1
Bit 0
0x0000
PTAD
—
—
PTAD5
—
—
—
—
PTAD0
0x0001
PTADD
—
—
PTADD5
—
—
—
—
PTADD0
0x0002
PTBD
—
—
PTBD5
PTBD4
PTBD3
PTBD2
PTBD1
PTBD0
0x0003
PTBDD
—
—
PTBDD5
PTBDD4
PTBDD3
PTBDD2
PTBDD1
PTBDD0
0x0004
PTCD
—
—
PTCD5
PTCD4
PTCD3
PTCD2
PTCD1
PTCD0
0x0005
PTCDD
—
—
PTCDD5
PTCDD4
PTCDD3
PTCDD2
PTCDD1
PTCDD0
0x0006
PTDD
PTDD7
—
—
—
—
PTDD2
PTDD1
PTDD0
0x0007
PTDDD
PTDDD7
—
—
—
—
PTDDD2
PTDDD1
PTDDD0
0x0008
PTED
0x0009
PTEDD
PTED7
PTED6
PTED5
PTED4
PTED3
PTED2
PTED1
PTED0
PTEDD7
PTEDD6
PTEDD5
PTEDD4
PTEDD3
PTEDD2
PTEDD1
PTEDD0
0x000A PTFD
—
PTFD6
PTFD5
PTFD4
—
—
PTFD1
PTFD0
0x000B PTFDD
—
PTFDD6
PTFDD5
PTFDD4
—
—
PTFDD1
PTFDD0
0x000C PTGD
—
—
PTGD5
PTGD4
PTGD3
PTGD2
PTGD1
PTGD0
0x000D PTGDD
—
—
PTGDD5
PTGDD4
PTGDD3
PTGDD2
PTGDD1
PTGDD0
0x000E
ACMPSC
ACME
ACBGS
ACF
ACIE
ACO
ACOPE
0x000F
Reserved
—
—
—
—
—
—
0x0010
ADCSC1
COCO
AIEN
ADCO
0x0011
ADCSC2
ADACT
ADTRG
ACFE
ACFGT
0
0
ACMOD
—
—
R
R
ADCH
0x0012
ADCRH
0
0
0
0
ADR11
ADR10
ADR9
ADR8
0x0013
ADCRL
ADR7
ADR6
ADR5
ADR4
ADR3
ADR2
ADR1
ADR0
0x0014
ADCCVH
0
0
0
0
ADCV11
ADCV10
ADCV9
ADCV8
0x0015
ADCCVL
ADCV7
ADCV6
ADCV5
ADCV4
ADCV3
ADCV2
ADCV1
ADCV0
0x0016
ADCCFG
ADLPC
0x0017
APCTL1
—
—
ADPC5
ADPC4
ADPC3
ADPC2
ADPC1
ADPC0
0x0018
APCTL2
ADIV
ADLSMP
MODE
ADICLK
—
—
—
—
—
—
ADPC9
ADPC8
0x0019 –
Reserved
0x001A
—
—
—
—
—
—
—
—
0x001B IRQSC
0
IRQPDD
IRQEDG
IRQPE
IRQF
IRQACK
IRQIE
IRQMOD
0x001C KBISC
0
0
0
0
KBF
KBACK
KBIE
KBMOD
0x001D KBIPE
KBIPE7
KBIPE6
KBIPE5
KBIPE4
0
KBIPE2
KBIPE1
KBIPE0
0x001E
KBIES
KBEDG7
KBEDG6
KBEDG5
KBEDG4
0
KBEDG2
KBEDG1
KBEDG0
0x001F
Reserved
—
—
—
—
—
—
—
—
0x0020
TPM1SC
TOF
TOIE
CPWMS
CLKSB
CLKSA
PS2
PS1
PS0
0x0021
TPM1CNTH
Bit 15
14
13
12
11
10
9
Bit 8
0x0022
TPM1CNTL
Bit 7
6
5
4
3
2
1
Bit 0
0x0023
TPM1MODH
Bit 15
14
13
12
11
10
9
Bit 8
0x0024
TPM1MODL
Bit 7
6
5
4
3
2
1
Bit 0
0x0025
TPM1C0SC
CH0F
CH0IE
MS0B
MS0A
ELS0B
ELS0A
0
0
0x0026
TPM1C0VH
Bit 15
14
13
12
11
10
9
Bit 8
0x0027
TPM1C0VL
Bit 7
6
5
4
3
2
1
Bit 0
0x0028
TPM1C1SC
CH1F
CH1IE
MS1B
MS1A
ELS1B
ELS1A
0
0
0x0029
TPM1C1VH
Bit 15
14
13
12
11
10
9
Bit 8
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
41
Chapter 4 Memory
Table 4-2. Direct-Page Register Summary (Sheet 2 of 4)
Address
Register
Name
Bit 7
6
5
4
3
2
1
Bit 0
0x002A TPM1C1VL
Bit 7
6
5
4
3
2
1
Bit 0
0x002B TPM1C2SC
CH2F
CH2IE
MS2B
MS2A
ELS2B
ELS2A
0
0
0x002C TPM1C2VH
Bit 15
14
13
12
11
10
9
Bit 8
0x002D TPM1C2VL
Bit 7
6
5
4
3
2
1
Bit 0
0x002E
TPM1C3SC
CH3F
CH3IE
MS3B
MS3A
ELS3B
ELS3A
0
0
0x002F
TPM1C3VH
Bit 15
14
13
12
11
10
9
Bit 8
0x0030
TPM1C3VL
Bit 7
6
5
4
3
2
1
Bit 0
—
—
—
—
—
—
—
—
LBKDIE
RXEDGIE
0
SBR12
SBR11
SBR10
SBR9
SBR8
0x0031 –
Reserved
0x0037
0x0038
SCI1BDH
0x0039
SCI1BDL
SBR7
SBR6
SBR5
SBR4
SBR3
SBR2
SBR1
SBR0
LOOPS
SCISWAI
RSRC
M
WAKE
ILT
PE
PT
0x003B SCI1C2
TIE
TCIE
RIE
ILIE
TE
RE
RWU
SBK
0x003C SCI1S1
TDRE
TC
RDRF
IDLE
OR
NF
FE
PF
0x003D SCI1S2
LBKDIF
RXEDGIF
0
RXINV
RWUID
BRK13
LBKDE
RAF
R8
T8
TXDIR
TXINV
ORIE
NEIE
FEIE
PEIE
0x003A SCI1C1
0x003E
SCI1C3
0x003F
SCI1D
0x0040
SCI2BDH
0x0041
SCI2BDL
0x0042
SCI2C1
Bit 7
6
5
4
3
2
1
Bit 0
LBKDIE
RXEDGIE
0
SBR12
SBR11
SBR10
SBR9
SBR8
SBR7
SBR6
SBR5
SBR4
SBR3
SBR2
SBR1
SBR0
LOOPS
SCISWAI
RSRC
M
WAKE
ILT
PE
PT
0x0043
SCI2C2
TIE
TCIE
RIE
ILIE
TE
RE
RWU
SBK
0x0044
SCI2S1
TDRE
TC
RDRF
IDLE
OR
NF
FE
PF
0x0045
SCI2S2
LBKDIF
RXEDGIF
0
RXINV
RWUID
BRK13
LBKDE
RAF
0x0046
SCI2C3
R8
T8
TXDIR
TXINV
ORIE
NEIE
FEIE
PEIE
Bit 7
6
5
4
3
0x0047
SCI2D
0x0048
MCGC1
CLKS
0x0049
MCGC2
BDIV
RDIV
RANGE
HGO
0x004A MCGTRM
LP
2
1
Bit 0
IREFS
IRCLKEN
IREFSTEN
EREFS
ERCLKEN
EREFSTEN
OSCINIT
FTRIM
TRIM
0x004B MCGSC
LOLS
LOCK
PLLST
IREFST
0x004C MCGC3
LOLIE
PLLS
CME
0
CLKST
0x004D MCGT
0
0
0
0
0
0
0
0
0x004E –
Reserved
0x004F
—
—
—
—
—
—
—
—
VDIV
0x0050
SPI1C1
SPIE
SPE
SPTIE
MSTR
CPOL
CPHA
SSOE
LSBFE
0x0051
SPI1C2
SPMIE
SPIMODE
0
MODFEN
BIDIROE
0
SPISWAI
SPC0
0x0052
SPI1BR
0
SPPR2
SPPR1
SPPR0
0
SPR2
SPR1
SPR0
0x0053
SPI1S
SPRF
SPMF
SPTEF
MODF
0
0
0
0
0x0054
SPI1DH
Bit 15
14
13
12
11
10
9
Bit 8
0x0055
SPI1DL
Bit 7
6
5
4
3
2
1
Bit 0
0x0056
SPI1MH
Bit 15
14
13
12
11
10
9
Bit 8
0x0057
SPI1ML
Bit 7
6
5
4
3
2
1
Bit 0
0x0058
IICA
AD7
AD6
AD5
AD4
AD3
AD2
AD1
0
MC9S08JM16 Series Data Sheet, Rev. 2
42
Freescale Semiconductor
Chapter 4 Memory
Table 4-2. Direct-Page Register Summary (Sheet 3 of 4)
Address
0x0059
Register
Name
Bit 7
IICF
6
5
4
3
1
Bit 0
TXAK
RSTA
0
0
0
SRW
IICIF
RXAK
MULT
ICR
0x005A IICC
IICEN
IICIE
MST
TX
0x005B IICS
TCF
IAAS
BUSY
ARBL
0x005C IICD
0x005D IICC2
2
DATA
GCAEN
ADEXT
0
0
0
AD10
AD9
AD8
—
—
—
—
—
—
—
—
PS1
PS0
0x005E –
Reserved
0x005F
0x0060
TPM2SC
TOF
TOIE
CPWMS
CLKSB
CLKSA
PS2
0x0061
TPM2CNTH
Bit 15
14
13
12
11
10
9
Bit 8
0x0062
TPM2CNTL
Bit 7
6
5
4
3
2
1
Bit 0
0x0063
TPM2MODH
Bit 15
14
13
12
11
10
9
Bit 8
0x0064
TPM2MODL
Bit 7
6
5
4
3
2
1
Bit 0
0x0065
TPM2C0SC
CH0F
CH0IE
MS0B
MS0A
ELS0B
ELS0A
0
0
0x0066
TPM2C0VH
Bit 15
14
13
12
11
10
9
Bit 8
0x0067
TPM2C0VL
Bit 7
6
5
4
3
2
1
Bit 0
0x0068
TPM2C1SC
CH1F
CH1IE
MS1B
MS1A
ELS1B
ELS1A
0
0
0x0069
TPM2C1VH
Bit 15
14
13
12
11
10
9
Bit 8
0x006A TPM2C1VL
Bit 7
6
5
4
3
2
1
Bit 0
—
—
—
—
—
—
—
0x006B Reserved
0x006C RTCSC
RTIF
—
RTCLKS
RTIE
RTCPS
0x006D RTCCNT
RTCCNT
0x006E
RTCMOD
RTCMOD
0x006F
Reserved
—
—
—
—
—
—
—
—
0x0070
SPI2C1
SPIE
SPE
SPTIE
MSTR
CPOL
CPHA
SSOE
LSBFE
0x0071
SPI2C2
SPMIE
SPIMODE
0
MODFEN
BIDIROE
0
SPISWAI
SPC0
0x0072
SPI2BR
0
SPPR2
SPPR1
SPPR0
0
SPR2
SPR1
SPR0
0x0073
SPI2S
SPRF
SPMF
SPTEF
MODF
0
0
0
0
0x0074
SPI2DH
Bit 15
14
13
12
11
10
9
Bit 8
0x0075
SPI2DL
Bit 7
6
5
4
3
2
1
Bit 0
0x0076
SPI2MH
Bit 15
14
13
12
11
10
9
Bit 8
0x0077
SPI2ML
Bit 7
6
5
4
3
2
1
Bit 0
—
—
—
—
—
—
—
—
0x0078 –
Reserved
0x0079
USBRESET
USBPU
USBRESMEN
LPRESF
—
USBVREN
—
USBPHYEN
0x0081 –
Reserved
0x0087
—
—
—
—
—
—
—
—
0x0088
PERID
0
0
ID5
ID4
ID3
ID2
ID1
ID0
0x0089
IDCOMP
0x0080
USBCTL0
0x008A REV
1
1
NID5
NID4
NID3
NID2
NID1
NID0
REV7
REV6
REV5
REV4
REV3
REV2
REV1
REV0
—
—
—
—
—
—
—
—
0x008B –
Reserved
0x008F
0x0090
INTSTAT
STALLF
—
RESUMEF
SLEEPF
TOKDNEF
SOFTOKF
ERRORF
USBRSTF
0x0091
INTENB
STALL
—
RESUME
SLEEP
TOKDNE
SOFTOK
ERROR
USBRST
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
43
Chapter 4 Memory
Table 4-2. Direct-Page Register Summary (Sheet 4 of 4)
Register
Name
Address
Bit 7
6
5
4
3
2
1
Bit 0
0x0092
ERRSTAT
BTSERRF
—
BUFERRF
BTOERRF
DFN8F
CRC16F
CRC5F
PIDERRF
0x0093
ERRENB
BTSERR
0
BUFERR
BTOERR
DFN8
CRC16
CRC5
PIDERR
0x0094
STAT
IN
ODD
0
0
0x0095
CTL
—
—
TSUSPEND
—
—
CRESUME
ODDRST
USBEN
ENDP
0x0096
ADDR
—
ADDR6
ADDR5
ADDR4
ADDR3
ADDR2
ADDR1
ADDR0
0x0097
FRMNUML
FRM7
FRM6
FRM5
FRM4
FRM3
FRM2
FRM1
FRM0
0x0098
FRMNUMH
0
0
0
0
0
FRM10
FRM9
FRM8
0x0099 –
Reserved
0x009C
—
—
—
—
—
—
—
—
0x009D EPCTL0
—
—
0
EPCTLDIS
EPRXEN
EPTXEN
EPSTALL
EPHSHK
0x009E
EPCTL1
—
—
0
EPCTLDIS
EPRXEN
EPTXEN
EPSTALL
EPHSHK
0x009F
EPCTL2
—
—
0
EPCTLDIS
EPRXEN
EPTXEN
EPSTALL
EPHSHK
0x00A0 EPCTL3
—
—
0
EPCTLDIS
EPRXEN
EPTXEN
EPSTALL
EPHSHK
0x00A1 EPCTL4
—
—
0
EPCTLDIS
EPRXEN
EPTXEN
EPSTALL
EPHSHK
0x00A2 EPCTL5
—
—
0
EPCTLDIS
EPRXEN
EPTXEN
EPSTALL
EPHSHK
0x00A3 EPCTL6
—
—
0
EPCTLDIS
EPRXEN
EPTXEN
EPSTALL
EPHSHK
0x00A4 –
Reserved
0x00AF
—
—
—
—
—
—
—
—
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 0x1800.
Table 4-3. High-Page Register Summary (Sheet 1 of 2)
Address
Register Name
0x1800
SRS
0x1801
SBDFR
Bit 7
6
5
4
3
2
1
Bit 0
POR
PIN
COP
ILOP
0
LOC
LVD
—
0
0
0
0
0
0
0
BDFR
STOPE
—
0
0
—
—
COPCLKS
COPW
0
0
0
SPI1FE
SPI2FE
ACIC
0x1804 –
Reserved
0x1805
—
—
—
—
—
—
—
—
0x1806
SDIDH
—
—
—
—
ID11
ID10
ID9
ID8
0x1807
SDIDL
ID7
ID6
ID5
ID4
ID3
ID2
ID1
ID0
0x1808
Reserved
—
—
—
—
—
—
—
—
BGBE
0x1802
SOPT1
0x1803
SOPT2
COPT
0x1809
SPMSC1
LVWF
LVWACK
LVWIE
LVDRE
LVDSE
LVDE
01
0x180A
SPMSC2
—
—
LVDV
LVWV
PPDF
PPDACK
—
PPDC
0x180B –
Reserved
0x180F
—
—
—
—
—
—
—
—
0x1810
DBGCAH
Bit 15
14
13
12
11
10
9
Bit 8
0x1811
DBGCAL
Bit 7
6
5
4
3
2
1
Bit 0
0x1812
DBGCBH
Bit 15
14
13
12
11
10
9
Bit 8
0x1813
DBGCBL
Bit 7
6
5
4
3
2
1
Bit 0
0x1814
DBGFH
Bit 15
14
13
12
11
10
9
Bit 8
0x1815
DBGFL
Bit 7
6
5
4
3
2
1
Bit 0
MC9S08JM16 Series Data Sheet, Rev. 2
44
Freescale Semiconductor
Chapter 4 Memory
Table 4-3. High-Page Register Summary (Sheet 2 of 2)
Address
Register Name
Bit 7
6
5
4
3
2
1
Bit 0
0x1816
DBGC
DBGEN
ARM
TAG
BRKEN
RWA
RWAEN
RWB
RWBEN
0x1817
DBGT
TRGSEL
BEGIN
0
0
TRG3
TRG2
TRG1
TRG0
0x1818
DBGS
AF
BF
ARMF
0
CNT3
CNT2
CNT1
CNT0
—
—
—
—
—
—
—
—
0x1819 –
Reserved
0x181F
0x1820
FCDIV
DIVLD
PRDIV8
DIV5
DIV4
DIV3
DIV2
DIV1
DIV0
0x1821
FOPT
KEYEN
FNORED
0
0
0
0
SEC01
SEC00
0x1822
Reserved
—
—
—
—
—
—
—
—
0x1823
FCNFG
0
0
KEYACC
0
0
0
0
0
0x1824
FPROT
FPS7
FPS6
FPS5
FPS4
FPS3
FPS2
FPS1
FPDIS
0x1825
FSTAT
FCBEF
FCCF
FPVIOL
FACCERR
0
FBLANK
0
0
0x1826
FCMD
FCMD7
FCMD6
FCMD5
FCMD4
FCMD3
FCMD2
FCMD1
FCMD0
0x1827 –
Reserved
0x183F
—
—
—
—
—
—
—
—
0x1840
PTAPE
—
—
PTAPE5
—
—
—
—
PTAPE0
0x1841
PTASE
—
—
PTASE5
—
—
—
—
PTASE0
0x1842
PTADS
—
—
PTADS5
—
—
—
—
PTADS0
0x1843
Reserved
—
—
—
—
—
—
—
—
0x1844
PTBPE
—
—
PTBPE5
PTBPE4
PTBPE3
PTBPE2
PTBPE1
PTBPE0
0x1845
PTBSE
—
—
PTBSE5
PTBSE4
PTBSE3
PTBSE2
PTBSE1
PTBSE0
0x1846
PTBDS
—
—
PTBDS5
PTBDS4
PTBDS3
PTBDS2
PTBDS1
PTBDS0
0x1847
Reserved
—
—
—
—
—
—
—
—
0x1848
PTCPE
—
—
PTCPE5
PTCPE4
PTCPE3
PTCPE2
PTCPE1
PTCPE0
0x1849
PTCSE
—
—
PTCSE5
PTCSE4
PTCSE3
PTCSE2
PTCSE1
PTCSE0
0x184A
PTCDS
—
—
PTCDS5
PTCDS4
PTCDS3
PTCDS2
PTCDS1
PTCDS0
0x184B
Reserved
0x184C
PTDPE
0x184D
0x184E
—
—
—
—
—
—
—
—
PTDPE7
—
—
—
—
PTDPE2
PTDPE1
PTDPE0
PTDSE
PTDSE7
—
—
—
—
PTDSE2
PTDSE1
PTDSE0
PTDDS
PTDDS7
—
—
—
—
PTDDS2
PTDDS1
PTDDS0
0x184F
Reserved
0x1850
PTEPE
0x1851
PTESE
PTESE7
PTESE6
PTESE5
PTESE4
PTESE3
PTESE2
PTESE1
PTESE0
0x1852
PTEDS
PTEDS7
PTEDS6
PTEDS5
PTEDS4
PTEDS3
PTEDS2
PTEDS1
PTEDS0
0x1853
Reserved
—
—
—
—
—
—
—
—
0x1854
PTFPE
—
PTFPE6
PTFPE5
PTFPE4
—
—
PTFPE1
PTFPE0
0x1855
PTFSE
—
PTFSE6
PTFSE5
PTFSE4
—
—
PTFSE1
PTFSE0
0x1856
PTFDS
—
PTFDS6
PTFDS5
PTFDS4
—
—
PTFDS1
PTFDS0
0x1857
Reserved
—
—
—
—
—
—
—
—
0x1858
PTGPE
—
—
PTGPE5
PTGPE4
PTGPE3
PTGPE2
PTGPE1
PTGPE0
0x1859
PTGSE
—
—
PTGSE5
PTGSE4
PTGSE3
PTGSE2
PTGSE1
PTGSE0
0x185A
PTGDS
—
—
PTGDS5
PTGDS4
PTGDS3
PTGDS2
PTGDS1
PTGDS0
—
—
—
—
—
—
—
—
0x185B –
Reserved
0x185F
—
—
—
—
—
—
—
—
PTEPE7
PTEPE6
PTEPE5
PTEPE4
PTEPE3
PTEPE2
PTEPE1
PTEPE0
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
45
Chapter 4 Memory
1
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
Register Name
Bit 7
6
5
4
3
2
1
Bit 0
0xFFAE
Reserved to store
FTRIM
0
0
0
0
0
0
0
FTRIM
0xFFAF
Reserved to store
MCGTRIM
TRIM
0xFFB0 –
NVBACKKEY
0xFFB7
0xFFB8 –
Reserved
0xFFBC
0xFFBD
NVPROT
0xFFBE
Reserved
0xFFBF
NVOPT
8-Byte Comparison Key
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
FPS7
FPS6
FPS5
FPS4
FPS3
FPS2
FPS1
FPDIS
—
—
—
—
—
—
—
—
KEYEN
FNORED
0
0
0
0
SEC01
SEC00
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 (System RAM)
The MC9S08JM16 series includes static RAM. The locations in RAM below 0x0100 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 M68HC05 MCUs, the HCS08 resets the stack pointer to 0x00FF. In the
MC9S08JM16 series, 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).
MC9S08JM16 Series Data Sheet, Rev. 2
46
Freescale Semiconductor
Chapter 4 Memory
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 4.6, “Security,” for a detailed
description of the security feature.
4.4
USB RAM
USB RAM is discussed in detail in Chapter 17, “Universal Serial Bus Device Controller (S08USBV1).”
4.5
Flash
Flash memory is used 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.
4.5.1
Features
Features of the flash memory include:
• Flash size
— MC9S08JM16 — 16, 384 bytes (32 pages of 512 bytes each)
— MC9S08JM8 — 8,192 bytes (16 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
4.5.2
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 4.7.1, “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
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
47
Chapter 4 Memory
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
4.5.3
Cycles of FCLK
Time if FCLK = 200 kHz
Byte program
9
45 μs
Byte program (burst)
4
20 μs1
Page erase
4000
20 ms
Mass erase
20,000
100 ms
Excluding start/end overhead
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 (0x05), byte program (0x20), burst program (0x25), page erase (0x40), and mass erase
(0x41). 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.
MC9S08JM16 Series Data Sheet, Rev. 2
48
Freescale Semiconductor
Chapter 4 Memory
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 4-2 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 must be
done once following a reset.
WRITE TO FCDIV1
FLASH PROGRAM AND
ERASE FLOW
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 2
FPVIOL OR
FACCERR?
YES
ERROR EXIT
NO
0
FCCF?
1
DONE
1
2
Required only once after reset.
Wait at least four bus cycles before checking FCBEF or FCCF.
Figure 4-2. Flash Program and Erase Flowchart
4.5.4
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
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
49
Chapter 4 Memory
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.
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 will be removed from the array.
MC9S08JM16 Series Data Sheet, Rev. 2
50
Freescale Semiconductor
Chapter 4 Memory
WRITE TO FCDIV1
FLASH BURST
PROGRAM FLOW
START
FACCERR?
1
0
CLEAR ERROR
FCBEF?
1
0
WRITE TO FLASH
TO BUFFER ADDRESS AND DATA
WRITE COMMAND (0x25) TO FCMD
WRITE 1 TO FCBEF
TO LAUNCH COMMAND
AND CLEAR FCBEF2
FPVIO OR
FACCERR?
NO
YES
YES
ERROR EXIT
NEW BURST COMMAND?
NO
0
FCCF?
1
DONE
1
2
Required only once after reset.
Wait at least four bus cycles before checking FCBEF or FCCF.
Figure 4-3. Flash Burst Program Flowchart
4.5.5
Access Errors
An access error occurs when 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)
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
51
Chapter 4 Memory
•
•
•
•
•
•
•
•
4.5.6
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 (0x05, 0x20, 0x25, 0x40, or 0x41)
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 (0x20, 0x25, or 0x40) 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
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, 0xFFFF. (see Section 4.7.4, “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 (address 0xE000 through 0xFFFF),
the FPS bits must be set to 1101 111 which results in the value 0xDFFF as the last address of unprotected
memory. In addition to programming the FPS bits to the appropriate value, FPDIS (bit 0 of NVPROT)
must be programmed to logic 0 to enable block protection. Therefore the value 0xDE must be programmed
into NVPROT to protect addresses 0xE000 through 0xFFFF.
FPS7 FPS6 FPS5 FPS4 FPS3
A15
A14
A13
A12
A11
FPS2
FPS1
A10
A9
1
1
1
1
1
1
1
1
1
A8 A7 A6 A5 A4 A3 A2 A1 A0
Figure 4-4. Block Protection Mechanism
MC9S08JM16 Series Data Sheet, Rev. 2
52
Freescale Semiconductor
Chapter 4 Memory
Block protection can 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 or reprogram operation.
4.5.7
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 0xFFBF 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 0xFFBD. All
of the interrupt vectors (memory locations 0xFFC0–0xFFFD) are redirected, though the reset vector
(0xFFFE:FFFF) is not.
For example, if 512 bytes of flash are protected, the protected address region is from 0xFE00 through
0xFFFF. The interrupt vectors (0xFFC0–0xFFFD) are redirected to the locations 0xFDC0–0xFDFD. Now,
if a TPM1 overflow interrupt is taken for instance, the values in the locations 0xFDE0:FDE1 are used for
the vector instead of the values in the locations 0xFFE0: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.
4.6
Security
The MC9S08JM16 series include 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
the MCU secure. During development, whenever the flash is erased, 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
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
53
Chapter 4 Memory
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 must 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 (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.
4.7
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.
MC9S08JM16 Series Data Sheet, Rev. 2
54
Freescale Semiconductor
Chapter 4 Memory
4.7.1
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 4-5. 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.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
55
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)
24 MHz
1
14
200 kHz
5 μs
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
4.7.2
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 4-6. 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 4.6, “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 4.6, “Security.”
MC9S08JM16 Series Data Sheet, Rev. 2
56
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.
4.7.3
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 4-7. 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 4.6, “Security.”
0 Writes to 0xFFB0–0xFFB7 are interpreted as the start of a flash programming or erase command.
1 Writes to NVBACKKEY (0xFFB0–0xFFB7) are interpreted as comparison key writes.
4.7.4
Flash Protection Register (FPROT and NVPROT)
During reset, the contents of the nonvolatile location NVPROT are 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 4-8. Flash Protection Register (FPROT)
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
57
Chapter 4 Memory
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
4.7.5
Flash Protection Disable
0 Flash block specified by FPS[7:1] is block protected (program and erase are 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 4-9. Flash Status Register (FSTAT)
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 1 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.
MC9S08JM16 Series Data Sheet, Rev. 2
58
Freescale Semiconductor
Chapter 4 Memory
Table 4-12. FSTAT Register Field Descriptions (continued)
Field
Description
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 4.5.5, “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 0xFF).
4.7.6
Flash Command Register (FCMD)
Only five command codes are recognized in normal user modes as shown in Table 4-14. Refer to
Section 4.5.3, “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 4-10. 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
0x05
mBlank
Byte program
0x20
mByteProg
Byte program — burst mode
0x25
mBurstProg
Page erase (512 bytes/page)
0x40
mPageErase
Mass erase (all flash)
0x41
mMassErase
All other command codes are illegal and generate an access error.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
59
Chapter 4 Memory
It is not necessary to perform a blank check command after a mass erase operation. Blank check is required
only as part of the security unlocking mechanism.
MC9S08JM16 Series Data Sheet, Rev. 2
60
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 MC9S08JM16 series. Some interrupt sources from peripheral modules are discussed in greater detail
in other chapters of this reference 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, 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
• Reset status register (SRS) to indicate source of most recent reset
• Separate interrupt vectors for each module (reduces polling overhead) (see Table 5-1)
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 (0xFFFE:0xFFFF). 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 0x00FF at reset.
The MC9S08JM16 series has eight sources for reset:
• Power-on reset (POR)
• Low-voltage detect (LVD)
• Computer operating properly (COP) timer
• Illegal opcode detect (ILOP)
• Illegal address detect (ILAD)
• Background debug forced reset
• External reset pin (RESET)
• Clock generator loss of lock and loss of clock reset (LOC)
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
61
Chapter 5 Resets, Interrupts, and System Configuration
Each of these sources, with the exception of the background debug forced reset, has an associated bit in
the system reset status (SRS) register.
5.4
Computer Operating Properly (COP) Watchdog
The COP watchdog is used 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 counter periodically. If the application program gets lost and fails to reset the COP counter
before it times out, a system reset is generated to force the system back to a known starting point.
After any reset, the COP watchdog is enabled (see Section 5.7.4, “System Options Register 1 (SOPT1),”
for additional information). If the COP watchdog is not used in an application, it can be disabled by
clearing COPT bits in SOPT1.
The COP counter is reset by writing 0x55 and 0xAA (in this order) to the address of SRS during the
selected timeout period. Writes do not affect the data in the read-only SRS. As soon as the write sequence
is done, the COP timeout period is restarted. If the program fails to do this during the time-out period, the
MCU will reset. Also, if any value other than 0x55 or 0xAA is written to SRS, the MCU is immediately
reset.
The COPCLKS bit in SOPT2 (see Section 5.7.5, “System Options Register 2 (SOPT2),” for additional
information) selects the clock source used for the COP timer. The clock source options are either the bus
clock or an internal 1 kHz clock source. With each clock source, there are three associated time-outs
controlled by the COPT bits in SOPT1. Table 5-6 summaries the control functions of the COPCLKS and
COPT bits. The COP watchdog defaults to operation from the 1 kHz clock source and the longest time-out
(210 cycles).
When the bus clock source is selected, windowed COP operation is available by setting COPW in the
SOPT2 register. In this mode, writes to the SRS register to clear the COP timer must occur in the last 25%
of the selected timeout period. A premature write immediately resets the MCU. When the 1 kHz clock
source is selected, windowed COP operation is not available.
The COP counter is initialized by the first writes to the SOPT1 and SOPT2 registers and after any system
reset. Subsequent writes to SOPT1 and SOPT2 have no effect on COP operation. Even if the application
will use the reset default settings of COPT, COPCLKS, and COPW bits, the user must write to the
write-once SOPT1 and SOPT2 registers during reset initialization to lock in the settings. This will prevent
accidental changes if the application program gets lost.
The write to SRS that services (clears) the COP counter must 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.
If the bus clock source is selected, the COP counter does not increment while the MCU is in background
debug mode or while the system is in stop mode. The COP counter resumes when the MCU exits
background debug mode or stop mode.
If the 1 kHz clock source is selected, the COP counter is re-initialized to zero upon entry to background
debug mode or stop mode and begins from zero upon exit from background debug mode or stop mode.
MC9S08JM16 Series Data Sheet, Rev. 2
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Freescale Semiconductor
Chapter 5 Resets, Interrupts, and System Configuration
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
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. 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.
If two or more interrupts are pending when the I bit is cleared, the highest priority source is serviced first
(see Table 5-1).
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
63
Chapter 5 Resets, Interrupts, and System Configuration
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.
TOWARD LOWER ADDRESSES
UNSTACKING
ORDER
7
0
5
1
CONDITION CODE REGISTER
4
2
ACCUMULATOR
3
3
2
4
PROGRAM COUNTER HIGH
1
5
PROGRAM COUNTER LOW
SP AFTER
INTERRUPT STACKING
INDEX REGISTER (LOW BYTE X)*
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 must be cleared at the beginning of the ISR, so that if another interrupt is generated by
this same source, it will be registered to 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 IRQSC must be 1 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.
MC9S08JM16 Series Data Sheet, Rev. 2
64
Freescale Semiconductor
Chapter 5 Resets, Interrupts, and System Configuration
The IRQ pin, when enabled, defaults to use an internal pull device (IRQPDD = 0), the device is a pullup
or pulldown depending on the polarity chosen. If the user desires to use an external pullup or pulldown,
the IRQPDD can be written to a 1 to turn off the internal device.
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.
NOTE
This pin does not contain a clamp diode to VDD and must not be driven
above VDD. The voltage measured on the internally 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.
5.5.2.2
Edge and Level Sensitivity
The IRQMOD control bit re-configure the detection logic to detect 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.
Table 5-1. Vector Summary (from Lowest to Highest Priority)
Vector
Number
Address
(High/Low)
31 to 30
0xFFC0:FFC1
0xFFC2:FFC3
29
0xFFC4:FFC5
Vrtc
System
control
RTIF
RTIE
RTC real-time interrupt
28
0xFFC6:FFC7
Viic
IIC
IICIF
IICIE
IIC
27
0xFFC8:FFC9
Vacmp
ACMP
ACF
ACIE
ACMP
26
0xFFCA:FFCB
Vadc
ADC
COCO
AIEN
ADC
25
0xFFCC:FFCD
Vkeyboard
KBI
KBF
KBIE
Keyboard pins
Vector Name
Module
Source
Enable
Description
Unused vector space (available for user program)
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
65
Chapter 5 Resets, Interrupts, and System Configuration
Table 5-1. Vector Summary (from Lowest to Highest Priority) (continued)
Vector
Number
Address
(High/Low)
Vector Name
Module
Source
Enable
Description
24
0xFFCE:FFCF
Vsci2tx
SCI2
TDRE
TC
TIE
TCIE
SCI2 transmit
23
0xFFD0:FFD1
Vsci2rx
SCI2
IDLE
RDRF
ILIE
RIE
SCI2 receive
ORIE
NFIE
FEIE
PFIE
SCI2 error
22
0xFFD2:FFD3
Vsci2err
SCI2
OR
NF
FE
PF
21
0xFFD4:FFD5
Vsci1tx
SCI1
TDRE
TC
TIE
TCIE
SCI1 transmit
20
0xFFD6:FFD7
Vsci1rx
SCI1
IDLE
RDRF
ILIE
RIE
SCI1 receive
ORIE
NFIE
FEIE
PFIE
SCI1 error
19
0xFFD8:FFD9
Vsci1err
SCI1
OR
NF
FE
PF
18
0xFFDA:FFDB
Vtpm2ovf
TPM2
TOF
TOIE
TPM2 overflow
17
0xFFDC:FFDD
Vtpm2ch1
TPM2
CH1F
CH1IE
TPM2 channel 1
16
0xFFDE:FFDF
Vtpm2ch0
TPM2
CH0F
CH0IE
TPM2 channel 0
15
0xFFE0:FFE1
Vtpm1ovf
TPM1
TOF
TOIE
TPM1 overflow
14
0xFFE2:FFE3
reserved
reserved
reserved
reserved
reserved
13
0xFFE4:FFE5
reserved
reserved
reserved
reserved
reserved
12
0xFFE6:FFE7
Vtpm1ch3
TPM1
CH3F
CH3IE
TPM1 channel 3
11
0xFFE8:FFE9
Vtpm1ch2
TPM1
CH2F
CH2IE
TPM1 channel 2
10
0xFFEA:FFEB
Vtpm1ch1
TPM1
CH1F
CH1IE
TPM1 channel 1
9
0xFFEC:FFED
Vtpm1ch0
TPM1
CH0F
CH0IE
TPM1 channel 0
8
0xFFEE:FFEF
reserved
—
—
—
—
USB
STALLF
RESUMEF
SLEEPF
TOKDNEF
SOFTOKF
ERRORF
USBRSTF
STALL
RESUME
SLEEP
TOKDNE
SOFTOK
ERROR
USBRST
USB Status
SPI2
SPRF
MODF
SPTEF
SPMF
SPIE
SPIE
SPTIE
SPMIE
SPI2
7
6
0xFFF0:FFF1
0xFFF2:FFF3
Vusb
Vspi2
MC9S08JM16 Series Data Sheet, Rev. 2
66
Freescale Semiconductor
Chapter 5 Resets, Interrupts, and System Configuration
Table 5-1. Vector Summary (from Lowest to Highest Priority) (continued)
Vector
Number
Vector Name
Module
Source
Enable
Description
SPIE
SPIE
SPTIE
SPMIE
SPI1
5
0xFFF4:FFF5
Vspi1
SPI1
SPRF
MODF
SPTEF
SPMF
4
0xFFF6:FFF7
Vlol
MCG
LOLS
LOLIE
MCG loss of lock
3
0xFFF8:FFF9
Vlvd
System
control
LVDF
LVDIE
Low-voltage detect
2
0xFFFA:FFFB
Virq
IRQ
IRQF
IRQIE
IRQ pin
1
0xFFFC:FFFD
Vswi
Core
SWI Instruction
—
Software interrupt
System
control
COP
LVD
RESET pin
Illegal opcode
Illegal address
LOC
POR
BDFR
COPE
LVDRE
—
ILOP
ILAD
CME
POR
Watchdog timer
Low-voltage detect
External pin
Illegal opcode
Illegal address
Loss of clock
Power-on-reset
BDM-forced reset
0
5.6
Address
(High/Low)
0xFFFE:FFFF
Vreset
Low-Voltage Detect (LVD) System
The MC9S08JM16 series includes a system to protect memory contents against low voltage conditions and
control MCU system states during supply voltage variations. The system is composed 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
an LVD reset or POR.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
67
Chapter 5 Resets, Interrupts, and System Configuration
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 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
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 SOPT1 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.”
5.7.1
Interrupt Pin Request Status and Control Register (IRQSC)
This direct-page register includes status and control bits, which are used to configure the IRQ function,
report status, and acknowledge IRQ events.
7
R
6
5
4
IRQPDD
IRQEDG
IRQPE
0
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)
MC9S08JM16 Series Data Sheet, Rev. 2
68
Freescale Semiconductor
Chapter 5 Resets, Interrupts, and System Configuration
Table 5-2. IRQSC Register Field Descriptions
Field
Description
6
IRQPDD
Interrupt Request (IRQ) Pull Device Disable — This read/write control bit is used to disable the internal pullup
device when the IRQ pin is enabled (IRQPE = 1) allowing for an external device to be used.
0 IRQ pull device enabled if IRQPE = 1.
1 IRQ pull device disabled if IRQPE = 1.
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.
0 IRQ pin function is disabled.
1 IRQ pin function is enabled.
3
IRQF
2
IRQACK
1
IRQIE
0
IRQMOD
5.7.2
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 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 an interrupt
request.
0 Interrupt request when IRQF set is disabled (use polling).
1 Interrupt requested whenever IRQF = 1.
IRQ Detection Mode — This read/write control bit selects either edge-only detection or edge-and-level
detection. See Section 5.5.2.2, “Edge and Level Sensitivity,” for more details.
0 IRQ event on falling/rising edges only.
1 IRQ event on falling/rising edges and low/high levels.
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.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
69
Chapter 5 Resets, Interrupts, and System Configuration
R
7
6
5
4
3
2
1
0
POR
PIN
COP
ILOP
0
LOC
LVD
—
0
1
0
W
Writing any value to SRS address clears COP watchdog timer.
POR
1
LVR:
U
0
0
(1)
Any
other
reset:
0
0
0
0
0
0
0
0
1
0
(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.
2
LOC
Loss-of-Clock Reset — Reset was caused by a loss of external clock.
0 Reset not caused by a loss of external clock.
1 Reset caused by a loss of external clock.
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.
5.7.3
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 0x00.
MC9S08JM16 Series Data Sheet, Rev. 2
70
Freescale Semiconductor
Chapter 5 Resets, Interrupts, and System Configuration
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.
5.7.4
System Options Register 1 (SOPT1)
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
must 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.
7
6
5
4
R
COPT
3
2
0
0
0
0
1
0
1
1
STOPE
W
Reset
1
1
0
1
= Unimplemented or Reserved
Figure 5-5. System Options Register (SOPT1)
Table 5-5. SOPT1 Register Field Descriptions
Field
7:6
COPT[1:0]
5
STOPE
Description
COP Watchdog Timeout — These write-once bits select the timeout period of the COP. COPT along with
COPCLKS in SOPT2 defines the COP timeout period. See Table 5-6.
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.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
71
Chapter 5 Resets, Interrupts, and System Configuration
Table 5-6. COP Configuration Options
Control Bits
COPCLKS
Clock Source
COP Window1 Opens
(COPW = 1)
COP Overflow Count
COPT[1:0]
N/A
0:0
N/A
N/A
COP is disabled
0
0:1
1 kHz LPO
clock
N/A
25 cycles (32 ms2)
0
1:0
1 kHz LPO
clock
N/A
28 cycles (256 ms1)
0
1:1
1 kHz LPO
clock
N/A
210 cycles (1.024 s1)
1
0:1
BUSCLK
6144 cycles
213 cycles
1
1:0
BUSCLK
49,152 cycles
216 cycles
1
1:1
BUSCLK
196,608 cycles
218 cycles
1
Windowed COP operation requires the user to clear the COP timer in the last 25% of the selected timeout period. This column
displays the minimum number of clock counts required before the COP timer can be reset in windowed COP mode (COPW = 1).
2 Values shown in milliseconds based on t
LPO = 1 ms. See tLPO in the appendix Section A.12.1, “Control Timing,” for the
tolerance of this value.
5.7.5
R
System Options Register 2 (SOPT2)
7
6
COPCLKS1
COPW1
0
0
5
4
3
0
0
0
2
1
0
SPI1FE
SPI2FE
ACIC
1
1
0
W
Reset
0
0
0
= Unimplemented or Reserved
1
This bit can be written only one time after reset. Additional writes are ignored.
Figure 5-6. System Options Register 2 (SOPT2)
Table 5-7. SOPT2 Register Field Descriptions
Field
7
COPCLKS
Description
COP Watchdog Clock Select — This write-once bit selects the clock source of the COP watchdog.
0 Internal 1 KHz LPO clock is source to COP.
1 Bus clock is source to COP.
6
COPW
COP Window — This write-once bit selects the COP operation mode. When set, the 0x55-0xAA write sequence
to the SRS register must occur in the last 25% of the selected period. Any write to the SRS register during the
first 75% of the selected period will reset the MCU.
0 Normal COP operation.
1 Window COP operation.
2
SPI1FE
SPI1 Ports Input Filter Enable
0 Disable input filter on SPI1 port pins to allow for higher maximum SPI baud rate.
1 Enable input filter on SPI1 port pins to eliminate noise and restrict maximum SPI baud rate.
MC9S08JM16 Series Data Sheet, Rev. 2
72
Freescale Semiconductor
Chapter 5 Resets, Interrupts, and System Configuration
Table 5-7. SOPT2 Register Field Descriptions (continued)
Field
1
SPI2FE
0
ACIC
5.7.6
Description
SPI2 Ports Input Filter Enable
0 Disable input filter on SPI2 port pins to allow for higher maximum SPI baud rate.
1 Enable input filter on SPI2 port pins to eliminate noise and restrict maximum SPI baud rate
Analog Comparator to Input Capture Enable— This bit connects the output of ACMP to TPM input channel 0.
0 ACMP output not connected to TPM input channel 0.
1 ACMP output connected to TPM input channel 0.
System Device Identification Register (SDIDH, SDIDL)
This read-only register is included, so host development systems can identify the HCS08 derivative and
revision number. 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 5-8. SDIDH Register Field Descriptions
Field
Description
7:4
Reserved
Bits 7:4 are reserved. Reading these bits will result in an indeterminate value; writes have no effect.
3:0
ID[11:8]
Part Identification Number — Each derivative in the HCS08 family has a unique identification number. The
MC9S08JM16 series is hard coded to the value 0x01E. See also ID bits in Table 5-9.
R
7
6
5
4
3
2
1
0
ID7
ID6
ID5
ID4
ID3
ID2
ID1
ID0
0
0
0
1
1
1
1
0
W
Reset
= Unimplemented or Reserved
Figure 5-8. System Device Identification Register — Low (SDIDL)
Table 5-9. 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
MC9S08JM16 series is hard coded to the value 0x01E. See also ID bits in Table 5-8.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
73
Chapter 5 Resets, Interrupts, and System Configuration
5.7.7
System Power Management Status and Control 1 Register
(SPMSC1)
This high page register contains status and control bits to support the low-voltage detect function, and to
enable the bandgap voltage reference for use by the ADC module. This register must 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.
7
R
LVWF
W
Reset:
6
1
5
4
3
2
LVWIE
LVDRE2
LVDSE
LVDE2
0
1
1
1
0
1
0
0
BGBE
LVWACK
0
0
0
0
= Unimplemented or Reserved
1
LVWF will be set in the case when VSupply transitions below the trip point or after reset and VSupply is already below VLVW.
2
This bit can be written only one time after reset. Additional writes are ignored.
Figure 5-9. System Power Management Status and Control 1 Register (SPMSC1)
Table 5-10. SPMSC1 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 is not present.
1 low-voltage warning is present or was present.
Low-Voltage Warning Acknowledge — If LVWF = 1, a low-voltage condition has occurred. To acknowledge this
low-voltage warning, write 1 to LVWACK, which will automatically clear LVWF to 0 if the low-voltage warning is
no longer present.
5
LVWIE
Low-Voltage Warning Interrupt Enable — This bit enables hardware interrupt requests for LVWF.
0 Hardware interrupt disabled (use polling).
1 Request a hardware interrupt when LVWF = 1.
4
LVDRE
Low-Voltage Detect Reset Enable — This write-once bit enables LVD events to generate a hardware reset
(provided LVDE = 1).
0 LVD events do not generate hardware resets.
1 Force an MCU reset when an enabled low-voltage detect event occurs.
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 write-once bit enables low-voltage detect logic and qualifies the operation
of other bits in this register.
0 LVD logic disabled.
1 LVD logic enabled.
0
BGBE
Bandgap Buffer Enable — This bit enables 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.
MC9S08JM16 Series Data Sheet, Rev. 2
74
Freescale Semiconductor
Chapter 5 Resets, Interrupts, and System Configuration
5.7.8
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. This register must 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.
R
7
6
0
0
5
4
LVDV
LVWV
3
2
1
PPDF
0
0
W
0
PPDC1
PPDACK
Power-on Reset:
0
0
0
0
0
0
0
0
LVD Reset:
0
0
u
u
0
0
0
0
Any other Reset:
0
0
u
u
0
0
0
0
= Unimplemented or Reserved
1
u = Unaffected by reset
This bit can be written only one time after reset. Additional writes are ignored.
Figure 5-10. System Power Management Status and Control 2 Register (SPMSC2)
Table 5-11. SPMSC2 Register Field Descriptions
Field
Description
5
LVDV
Low-Voltage Detect Voltage Select — This write-once bit selects the low-voltage detect (LVD) trip point
setting. It also selects the warning voltage range. See Table 5-12.
4
LVWV
Low-Voltage Warning Voltage Select — This bit selects the low-voltage warning (LVW) trip point
voltage.See Table 5-12.
3
PPDF
Partial Power Down Flag — This read-only status bit indicates that the MCU has recovered from stop2
mode.
0 MCU has not recovered from stop2 mode.
1 MCU recovered from stop2 mode.
2
PPDACK
0
PPDC
Partial Power Down Acknowledge — Writing a 1 to PPDACK clears the PPDF bit.
Partial Power Down Control — This write-once bit controls whether stop2 or stop3 mode is selected.
0 Stop3 mode enabled.
1 Stop2, partial power down, mode enabled.
Table 5-12. LVD and LVW Trip Point Typical Values1
1
LVDV:LVWV
LVW Trip Point
LVD Trip Point
0:0
VLVW0 = 2.74 V
VLVD0 = 2.56 V
0:1
VLVW1 = 2.92 V
1:0
VLVW2 = 4.3 V
1:1
VLVW3 = 4.6 V
VLVD1 = 4.0 V
See Electrical Characteristics appendix for minimum and maximum values.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
75
Chapter 5 Resets, Interrupts, and System Configuration
MC9S08JM16 Series Data Sheet, Rev. 2
76
Freescale Semiconductor
Chapter 6
Parallel Input/Output
6.1
Introduction
This chapter explains software controls related to parallel input/output (I/O). The MC9S08JM16 has seven
I/O ports which include a total of 37 general-purpose I/O pins. See Chapter 2, “Pins and Connections,” for
more information about the logic and hardware aspects of these pins.
Not all pins are available on all devices. See Table 2-1 to determine which functions are available for a
specific device.
Many of the I/O pins are shared with on-chip peripheral functions, as shown in Table 2-1. The peripheral
modules have priority over the I/Os, so when a peripheral is enabled, the I/O functions are disabled.
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).
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 must either enable on-chip pullup devices
or change the direction of unconnected pins to outputs so the pins do not
float.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
77
Chapter 6 Parallel Input/Output
6.2
Port Data and Data Direction
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 6-1. 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.
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.
MC9S08JM16 Series Data Sheet, Rev. 2
78
Freescale Semiconductor
Chapter 6 Parallel Input/Output
6.3
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.
6.3.1
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.
6.3.2
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.
6.3.3
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.
6.4
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 must
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 must 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.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
79
Chapter 6 Parallel Input/Output
6.5
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.
6.5.1
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
R
PTAD5
PTAD0
W
Reset
0
0
0
0
0
0
0
0
Figure 6-2. Port A Data Register (PTAD)
Table 6-1. PTAD Register Field Descriptions
Field
Description
5,0
PTAD[5,0]
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.
7
6
5
4
3
2
1
0
R
PTADD5
PTADD0
W
Reset
0
0
0
0
0
0
0
0
Figure 6-3. Data Direction for Port A Register (PTADD)
Table 6-2. PTADD Register Field Descriptions
Field
Description
5,0
Data Direction for Port A Bits — These read/write bits control the direction of port A pins and what is read for
PTADD[5,0] 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.
MC9S08JM16 Series Data Sheet, Rev. 2
80
Freescale Semiconductor
Chapter 6 Parallel Input/Output
6.5.2
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
R
PTAPE5
PTAPE0
W
Reset
0
0
0
0
0
0
0
0
Figure 6-4. Internal Pullup Enable for Port A (PTAPE)
Table 6-3. PTADD Register Field Descriptions
Field
Description
5,0
Internal Pullup Enable for Port A Bits — Each of these control bits determines if the internal pullup device is
PTAPE[5,0] 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.
7
6
5
4
3
2
1
0
R
PTASE5
PTASE0
W
Reset
0
0
1
1
1
1
1
1
Figure 6-5. Output Slew Rate Control Enable for Port A (PTASE)
Table 6-4. PTASE Register Field Descriptions
Field
Description
5,0
Output Slew Rate Control Enable for Port A Bits — Each of these control bits determine whether output slew
PTASE[5,0] 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
R
PTADS5
PTADS0
W
Reset
0
0
0
0
0
0
0
0
Figure 6-6. Output Drive Strength Selection for Port A (PTASE)
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
81
Chapter 6 Parallel Input/Output
Table 6-5. PTASE Register Field Descriptions
Field
Description
5,0
Output Drive Strength Selection for Port A Bits — Each of these control bits selects between low and high
PTADS[5,0] 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.
6.5.3
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
PTBD5
PTBD4
PTBD3
PTBD2
PTBD1
PTBD0
0
0
0
0
0
0
R
W
Reset
0
0
Figure 6-7. Port B Data Register (PTBD)
Table 6-6. PTBD Register Field Descriptions
Field
Description
5:0
PTBD[5:0]
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
PTBDD5
PTBDD4
PTBDD3
PTBDD2
PTBDD1
PTBDD0
0
0
0
0
0
0
R
W
Reset
0
0
Figure 6-8. Data Direction for Port B (PTBDD)
Table 6-7. PTBDD Register Field Descriptions
Field
Description
5:0
Data Direction for Port B Bits — These read/write bits control the direction of port B pins and what is read for
PTBDD[5:0] 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.
MC9S08JM16 Series Data Sheet, Rev. 2
82
Freescale Semiconductor
Chapter 6 Parallel Input/Output
6.5.4
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
PTBPE5
PTBPE4
PTBPE3
PTBPE2
PTBPE1
PTBPE0
0
0
0
0
0
0
R
W
Reset
0
0
Figure 6-9. Internal Pullup Enable for Port B (PTBPE)
Table 6-8. PTBPE Register Field Descriptions
Field
Description
5:0
Internal Pullup Enable for Port B Bits — Each of these control bits determines if the internal pullup device is
PTBPE[5:0] 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
PTBSE5
PTBSE4
PTBSE3
PTBSE2
PTBSE1
PTBSE0
1
1
1
1
1
1
R
W
Reset
0
0
Figure 6-10. Output Slew Rate Control Enable (PTBSE)
Table 6-9. PTBSE Register Field Descriptions
Field
Description
5:0
Output Slew Rate Control Enable for Port B Bits— Each of these control bits determine whether output slew
PTBSE[5:0] 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.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
83
Chapter 6 Parallel Input/Output
7
6
5
4
3
2
1
0
PTBDS5
PTBDS4
PTBDS3
PTBDS2
PTBDS1
PTBDS0
0
0
0
0
0
0
R
W
Reset
0
0
Figure 6-11. Output Drive Strength Selection for Port B (PTBDS)
Table 6-10. PTBDS Register Field Descriptions
Field
Description
5:0
Output Drive Strength Selection for Port B Bits — Each of these control bits selects between low and high
PTBDS[5:0] 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.
6.5.5
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
PTCD5
PTCD4
PTCD3
PTCD2
PTCD1
PTCD0
0
0
0
0
0
0
R
W
Reset
0
0
Figure 6-12. Port C Data Register (PTCD)
Table 6-11. PTCD Register Field Descriptions
Field
Description
5:0
PTCD[5:0]
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.
MC9S08JM16 Series Data Sheet, Rev. 2
84
Freescale Semiconductor
Chapter 6 Parallel Input/Output
7
6
5
4
3
2
1
0
PTCDD5
PTCDD4
PTCDD3
PTCDD2
PTCDD1
PTCDD0
0
0
0
0
0
0
R
W
Reset
0
0
Figure 6-13. Data Direction for Port C (PTCDD)
Table 6-12. PTCDD Register Field Descriptions
Field
Description
5:0
Data Direction for Port C Bits — These read/write bits control the direction of port C pins and what is read for
PTCDD[5:0] 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.
6.5.6
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
PTCPE5
PTCPE4
PTCPE3
PTCPE2
PTCPE1
PTCPE0
0
0
0
0
0
0
R
W
Reset
0
0
Figure 6-14. Internal Pullup Enable for Port C (PTCPE)
Table 6-13. PTCPE Register Field Descriptions
Field
Description
5:0
Internal Pullup Enable for Port C Bits — Each of these control bits determines if the internal pullup device is
PTCPE[5:0] 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.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
85
Chapter 6 Parallel Input/Output
7
6
5
4
3
2
1
0
PTCSE5
PTCSE4
PTCSE3
PTCSE2
PTCSE1
PTCSE0
1
1
1
1
1
1
R
W
Reset
0
0
Figure 6-15. Output Slew Rate Control Enable for Port C (PTCSE)
Table 6-14. PTCSE Register Field Descriptions
Field
Description
5:0
Output Slew Rate Control Enable for Port C Bits — Each of these control bits determine whether output slew
PTCSE[5:0] 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.
7
6
5
4
3
2
1
0
PTCDS5
PTCDS4
PTCDS3
PTCDS2
PTCDS1
PTCDS0
0
0
0
0
0
0
R
W
Reset
0
0
Figure 6-16. Output Drive Strength Selection for Port C (PTCDS)
Table 6-15. PTCDS Register Field Descriptions
Field
Description
5:0
Output Drive Strength Selection for Port C Bits — Each of these control bits selects between low and high
PTCDS[5:0] 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.
MC9S08JM16 Series Data Sheet, Rev. 2
86
Freescale Semiconductor
Chapter 6 Parallel Input/Output
6.5.7
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
PTDD2
PTDD1
PTDD0
0
0
0
R
PTDD7
W
Reset
0
0
0
0
0
Figure 6-17. Port D Data Register (PTDD)
Table 6-16. PTDD Register Field Descriptions
Field
Description
7, 2:0
Port D Data Register Bits — For port D pins that are inputs, reads return the logic level on the pin. For port D
PTDD[7, 2:0] 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
PTDDD2
PTDDD1
PTDDD0
0
0
0
R
PTDDD7
W
Reset
0
0
0
0
0
Figure 6-18. Data Direction for Port D (PTDDD)
Table 6-17. PTDDD Register Field Descriptions
Field
Description
7, 2:0
PTDDD[7, 2:0]
Data Direction for Port D Bits — These read/write bits control the direction of port D pins and what is read for
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.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
87
Chapter 6 Parallel Input/Output
6.5.8
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
PTDPE2
PTDPE1
PTDPE0
0
0
0
R
PTDPE7
W
Reset
0
0
0
0
0
Figure 6-19. Internal Pullup Enable for Port D (PTDPE)
Table 6-18. PTDPE Register Field Descriptions
Field
Description
7, 2:0
Internal Pullup Enable for Port D Bits — Each of these control bits determines if the internal pullup device is
PTDPE[7, 2:0] 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
PTDSE2
PTDSE1
PTDSE0
1
1
1
R
PTDSE7
W
Reset
1
1
1
1
1
Figure 6-20. Output Slew Rate Control Enable for Port D (PTDSE)
Table 6-19. PTDSE Register Field Descriptions
Field
Description
7, 2:0
Output Slew Rate Control Enable for Port D Bits — Each of these control bits determine whether output slew
PTDSE[7, 2:0] 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.
MC9S08JM16 Series Data Sheet, Rev. 2
88
Freescale Semiconductor
Chapter 6 Parallel Input/Output
7
6
5
4
3
2
1
0
PTDDS2
PTDDS1
PTDDS0
0
0
0
R
PTDDS7
W
Reset
0
0
0
0
0
Figure 6-21. Output Drive Strength Selection for Port D (PTDDS)
Table 6-20. PTDDS Register Field Descriptions
Field
Description
7, 2:0
Output Drive Strength Selection for Port D Bits — Each of these control bits selects between low and high
PTDDS[7, 2:0] 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.
6.5.9
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 6-22. Port E Data Register (PTED)
Table 6-21. 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.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
89
Chapter 6 Parallel Input/Output
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 6-23. Data Direction for Port E (PTEDD)
Table 6-22. 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.
MC9S08JM16 Series Data Sheet, Rev. 2
90
Freescale Semiconductor
Chapter 6 Parallel Input/Output
6.5.10
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 6-24. Internal Pullup Enable for Port E (PTEPE)
Table 6-23. 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 6-25. Output Slew Rate Control Enable for Port E (PTESE)
Table 6-24. 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.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
91
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 6-26. Output Drive Strength Selection for Port E (PTEDS)
Table 6-25. 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.
6.5.11
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
PTFD6
PTFD5
PTFD4
0
0
0
2
1
0
PTFD1
PTFD0
0
0
R
W
Reset
0
0
0
Figure 6-27. Port F Data Register (PTFD)
Table 6-26. PTFD Register Field Descriptions
Field
Description
6:4, 1:0
PTFD
[6:4, 1:0]
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.
MC9S08JM16 Series Data Sheet, Rev. 2
92
Freescale Semiconductor
Chapter 6 Parallel Input/Output
7
6
5
4
3
PTFDD6
PTFDD5
PTFDD4
0
0
0
2
1
0
PTFDD1
PTFDD0
0
0
R
W
Reset
0
0
0
Figure 6-28. Data Direction for Port F (PTFDD)
Table 6-27. PTFDD Register Field Descriptions
Field
Description
6:4, 1:0
PTFDD
[6:4, 1:0]
Data Direction for Port F Bits — These read/write bits control the direction of port F pins and what is read for
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.
6.5.12
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
PTFPE6
PTFPE5
PTFPE4
0
0
0
2
1
0
PTFPE1
PTFPE0
0
0
R
W
Reset
0
0
0
Figure 6-29. Internal Pullup Enable for Port F (PTFPE)
Table 6-28. PTFPE Register Field Descriptions
Field
Description
6:4, 1:0
PTFPE
[6:4, 1:0]
Internal Pullup Enable for Port F Bits — Each of these control bits determines if the internal pullup device is
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.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
93
Chapter 6 Parallel Input/Output
7
6
5
4
3
PTFSE6
PTFSE5
PTFSE4
1
1
1
2
1
0
PTFSE1
PTFSE0
1
1
R
W
Reset
0
1
1
Figure 6-30. Output Slew Rate Control Enable for Port F (PTFSE)
Table 6-29. PTFSE Register Field Descriptions
Field
Description
6:4, 1:0
PTFSE
[6:4, 1:0]
Output Slew Rate Control Enable for Port F Bits — Each of these control bits determine whether output slew
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.
7
6
5
4
3
PTFDS6
PTFDS5
PTFDS4
0
0
0
2
1
0
PTFDS1
PTFDS0
0
0
R
W
Reset
0
0
0
Figure 6-31. Output Drive Strength Selection for Port F (PTFDS)
Table 6-30. PTFDS Register Field Descriptions
Field
6:4, 1:0
PTFDS
[6:4, 1:0]
Description
Output Drive Strength Selection for Port F Bits — Each of these control bits selects between low and high
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.
MC9S08JM16 Series Data Sheet, Rev. 2
94
Freescale Semiconductor
Chapter 6 Parallel Input/Output
6.5.13
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
PTGD5
PTGD4
PTGD3
PTGD2
PTGD1
PTGD0
0
0
0
0
0
0
R
W
Reset
0
0
Figure 6-32. Port G Data Register (PTGD)
Table 6-31. PTGD Register Field Descriptions
Field
Description
5:0
PTGD[5:0]
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
PTGDD5
PTGDD4
PTGDD3
PTGDD2
PTGDD1
PTGDD0
0
0
0
0
0
0
R
W
Reset
0
0
Figure 6-33. Data Direction for Port G (PTGDD)
Table 6-32. PTGDD Register Field Descriptions
Field
Description
5:0
Data Direction for Port G Bits — These read/write bits control the direction of port G pins and what is read for
PTGDD[5:0] 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.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
95
Chapter 6 Parallel Input/Output
6.5.14
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
PTGPE5
PTGPE4
PTGPE3
PTGPE2
PTGPE1
PTGPE0
0
0
0
0
0
0
R
W
Reset
0
0
Figure 6-34. Internal Pullup Enable for Port G Bits (PTGPE)
Table 6-33. PTGPE Register Field Descriptions
Field
Description
5:0
PTGPEn
Internal Pullup Enable for Port G Bits — Each of these control bits determines if the internal pullup device is
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
PTGSE5
PTGSE4
PTGSE3
PTGSE2
PTGSE1
PTGSE0
1
1
1
1
1
1
R
W
Reset
0
0
Figure 6-35. Output Slew Rate Control Enable for Port G Bits (PTGSE)
Table 6-34. PTGSE Register Field Descriptions
Field
Description
5:0
PTGSEn
Output Slew Rate Control Enable for Port G Bits— Each of these control bits determine whether output slew
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.
MC9S08JM16 Series Data Sheet, Rev. 2
96
Freescale Semiconductor
Chapter 6 Parallel Input/Output
7
6
5
4
3
2
1
0
PTGDS5
PTGDS4
PTGDS3
PTGDS2
PTGDS1
PTGDS0
0
0
0
0
0
0
R
W
Reset
0
0
Figure 6-36. Output Drive Strength Selection for Port G (PTGDS)
Table 6-35. PTGDS Register Field Descriptions
Field
5:0
PTGDSn
Description
Output Drive Strength Selection for Port G Bits — Each of these control bits selects between low and high
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.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
97
Chapter 6 Parallel Input/Output
MC9S08JM16 Series Data Sheet, Rev. 2
98
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
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
99
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.
0
7
ACCUMULATOR
A
16-BIT INDEX REGISTER H:X
H INDEX REGISTER (HIGH)
8
15
INDEX REGISTER (LOW)
7
0
SP
STACK POINTER
15
X
0
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.
MC9S08JM16 Series Data Sheet, Rev. 2
100
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 0xFFFE and 0xFFFF.
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.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
101
Chapter 7 Central Processor Unit (S08CPUV2)
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
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
MC9S08JM16 Series Data Sheet, Rev. 2
102
Freescale Semiconductor
Chapter 7 Central Processor Unit (S08CPUV2)
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
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.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
103
Chapter 7 Central Processor Unit (S08CPUV2)
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.
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.
MC9S08JM16 Series Data Sheet, Rev. 2
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Freescale Semiconductor
Chapter 7 Central Processor Unit (S08CPUV2)
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.
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 must 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
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
105
Chapter 7 Central Processor Unit (S08CPUV2)
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.
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.
MC9S08JM16 Series Data Sheet, Rev. 2
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Freescale Semiconductor
Chapter 7 Central Processor Unit (S08CPUV2)
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.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
107
Chapter 7 Central Processor Unit (S08CPUV2)
7.5
HCS08 Instruction Set Summary
Table 7-2 provides a summary of the HCS08 instruction set in all possible addressing modes. The table
shows operand construction, execution time in internal bus clock cycles, and cycle-by-cycle details for
each addressing mode variation of each instruction.
ADC
ADC
ADC
ADC
ADC
ADC
ADC
ADC
#opr8i
opr8a
opr16a
oprx16,X
oprx8,X
,X
oprx16,SP
oprx8,SP
ADD
ADD
ADD
ADD
ADD
ADD
ADD
ADD
#opr8i
opr8a
opr16a
oprx16,X
oprx8,X
,X
oprx16,SP
oprx8,SP
Operation
Add with Carry
A ← (A) + (M) + (C)
Add without Carry
A ← (A) + (M)
Object Code
IMM
DIR
EXT
IX2
IX1
IX
SP2
SP1
A9
B9
C9
D9
E9
F9
9E D9
9E E9
ii
dd
hh ll
ee ff
ff
IMM
DIR
EXT
IX2
IX1
IX
SP2
SP1
AB
BB
CB
DB
EB
FB
9E DB
9E EB
ii
dd
hh ll
ee ff
ff
ee ff
ff
ee ff
ff
Cycles
Source
Form
Address
Mode
Table 7-2. . Instruction Set Summary (Sheet 1 of 9)
Cyc-by-Cyc
Details
Affect
on CCR
VH I N Z C
2
3
4
4
3
3
5
4
pp
rpp
prpp
prpp
rpp
rfp
pprpp
prpp
–
2
3
4
4
3
3
5
4
pp
rpp
prpp
prpp
rpp
rfp
pprpp
prpp
–
AIS #opr8i
Add Immediate Value (Signed) to
Stack Pointer
SP ← (SP) + (M)
IMM
A7 ii
2
pp
–– – – – –
AIX #opr8i
Add Immediate Value (Signed) to
Index Register (H:X)
H:X ← (H:X) + (M)
IMM
AF ii
2
pp
–– – – – –
Logical AND
A ← (A) & (M)
IMM
DIR
EXT
IX2
IX1
IX
SP2
SP1
A4
B4
C4
D4
E4
F4
9E D4
9E E4
2
3
4
4
3
3
5
4
pp
rpp
prpp
prpp
rpp
rfp
pprpp
prpp
0– –
DIR
INH
INH
IX1
IX
SP1
38 dd
48
58
68 ff
78
9E 68 ff
5
1
1
5
4
6
rfwpp
p
p
rfwpp
rfwp
prfwpp
– –
DIR
INH
INH
IX1
IX
SP1
37 dd
47
57
67 ff
77
9E 67 ff
5
1
1
5
4
6
rfwpp
p
p
rfwpp
rfwp
prfwpp
– –
REL
24 rr
3
ppp
AND
AND
AND
AND
AND
AND
AND
AND
#opr8i
opr8a
opr16a
oprx16,X
oprx8,X
,X
oprx16,SP
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
Arithmetic Shift Left
C
0
b7
b0
(Same as LSL)
Arithmetic Shift Right
C
b7
b0
Branch if Carry Bit Clear
(if C = 0)
ii
dd
hh ll
ee ff
ff
ee ff
ff
–
–– – – – –
MC9S08JM16 Series Data Sheet, Rev. 2
108
Freescale Semiconductor
Chapter 7 Central Processor Unit (S08CPUV2)
Operation
Object Code
Cycles
Source
Form
Address
Mode
Table 7-2. . Instruction Set Summary (Sheet 2 of 9)
Cyc-by-Cyc
Details
Affect
on CCR
VH I N Z C
BCLR n,opr8a
Clear Bit n in Memory
(Mn ← 0)
DIR (b0)
DIR (b1)
DIR (b2)
DIR (b3)
DIR (b4)
DIR (b5)
DIR (b6)
DIR (b7)
BCS rel
Branch if Carry Bit Set (if C = 1)
(Same as BLO)
REL
25 rr
3
ppp
–– – – – –
BEQ rel
Branch if Equal (if Z = 1)
REL
27 rr
3
ppp
–– – – – –
BGE rel
Branch if Greater Than or Equal To
(if N ⊕ V = 0) (Signed)
REL
90 rr
3
ppp
–– – – – –
BGND
Enter active background if ENBDM=1
Waits for and processes BDM commands
until GO, TRACE1, or TAGGO
INH
82
5+
fp...ppp
–– – – – –
BGT rel
Branch if Greater Than (if Z | (N ⊕ V) = 0)
(Signed)
REL
92 rr
3
ppp
–– – – – –
BHCC rel
Branch if Half Carry Bit Clear (if H = 0)
REL
28 rr
3
ppp
–– – – – –
BHCS rel
Branch if Half Carry Bit Set (if H = 1)
REL
29 rr
3
ppp
–– – – – –
BHI rel
Branch if Higher (if C | Z = 0)
REL
22 rr
3
ppp
–– – – – –
BHS rel
Branch if Higher or Same (if C = 0)
(Same as BCC)
REL
24 rr
3
ppp
–– – – – –
BIH rel
Branch if IRQ Pin High (if IRQ pin = 1)
REL
2F rr
3
ppp
–– – – – –
BIL rel
Branch if IRQ Pin Low (if IRQ pin = 0)
REL
2E rr
3
ppp
–– – – – –
Bit Test
(A) & (M)
(CCR Updated but Operands Not Changed)
IMM
DIR
EXT
IX2
IX1
IX
SP2
SP1
2
3
4
4
3
3
5
4
pp
rpp
prpp
prpp
rpp
rfp
pprpp
prpp
0– –
BIT
BIT
BIT
BIT
BIT
BIT
BIT
BIT
#opr8i
opr8a
opr16a
oprx16,X
oprx8,X
,X
oprx16,SP
oprx8,SP
11
13
15
17
19
1B
1D
1F
dd
dd
dd
dd
dd
dd
dd
dd
5
5
5
5
5
5
5
5
rfwpp
rfwpp
rfwpp
rfwpp
rfwpp
rfwpp
rfwpp
rfwpp
–– – – – –
A5
B5
C5
D5
E5
F5
9E D5
9E E5
ii
dd
hh ll
ee ff
ff
ee ff
ff
–
BLE rel
Branch if Less Than or Equal To
(if Z | (N ⊕ V) = 1) (Signed)
REL
93 rr
3
ppp
–– – – – –
BLO rel
Branch if Lower (if C = 1) (Same as BCS)
REL
25 rr
3
ppp
–– – – – –
BLS rel
Branch if Lower or Same (if C | Z = 1)
REL
23 rr
3
ppp
–– – – – –
BLT rel
Branch if Less Than (if N ⊕ V = 1) (Signed)
REL
91 rr
3
ppp
–– – – – –
BMC rel
Branch if Interrupt Mask Clear (if I = 0)
REL
2C rr
3
ppp
–– – – – –
BMI rel
Branch if Minus (if N = 1)
REL
2B rr
3
ppp
–– – – – –
BMS rel
Branch if Interrupt Mask Set (if I = 1)
REL
2D rr
3
ppp
–– – – – –
BNE rel
Branch if Not Equal (if Z = 0)
REL
26 rr
3
ppp
–– – – – –
BPL rel
Branch if Plus (if N = 0)
REL
2A rr
3
ppp
–– – – – –
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
109
Chapter 7 Central Processor Unit (S08CPUV2)
BRA rel
Operation
Object Code
Branch Always (if I = 1)
REL
20 rr
BRCLR n,opr8a,rel
Branch if Bit n in Memory Clear (if (Mn) = 0)
DIR (b0)
DIR (b1)
DIR (b2)
DIR (b3)
DIR (b4)
DIR (b5)
DIR (b6)
DIR (b7)
01
03
05
07
09
0B
0D
0F
BRN rel
Branch Never (if I = 0)
REL
21 rr
Branch if Bit n in Memory Set (if (Mn) = 1)
DIR (b0)
DIR (b1)
DIR (b2)
DIR (b3)
DIR (b4)
DIR (b5)
DIR (b6)
DIR (b7)
00
02
04
06
08
0A
0C
0E
dd
dd
dd
dd
dd
dd
dd
dd
BSET n,opr8a
Set Bit n in Memory (Mn ← 1)
DIR (b0)
DIR (b1)
DIR (b2)
DIR (b3)
DIR (b4)
DIR (b5)
DIR (b6)
DIR (b7)
10
12
14
16
18
1A
1C
1E
BSR rel
Branch to Subroutine
PC ← (PC) + $0002
push (PCL); SP ← (SP) – $0001
push (PCH); SP ← (SP) – $0001
PC ← (PC) + rel
REL
BRSET n,opr8a,rel
Cycles
Source
Form
Address
Mode
Table 7-2. . Instruction Set Summary (Sheet 3 of 9)
Cyc-by-Cyc
Details
Affect
on CCR
VH I N Z C
3
ppp
–– – – – –
5
5
5
5
5
5
5
5
rpppp
rpppp
rpppp
rpppp
rpppp
rpppp
rpppp
rpppp
–– – – –
3
ppp
–– – – – –
5
5
5
5
5
5
5
5
rpppp
rpppp
rpppp
rpppp
rpppp
rpppp
rpppp
rpppp
–– – – –
dd
dd
dd
dd
dd
dd
dd
dd
5
5
5
5
5
5
5
5
rfwpp
rfwpp
rfwpp
rfwpp
rfwpp
rfwpp
rfwpp
rfwpp
–– – – – –
AD rr
5
ssppp
–– – – – –
5
4
4
5
5
6
rpppp
pppp
pppp
rpppp
rfppp
prpppp
–– – – – –
dd
dd
dd
dd
dd
dd
dd
dd
rr
rr
rr
rr
rr
rr
rr
rr
rr
rr
rr
rr
rr
rr
rr
rr
CBEQ opr8a,rel
CBEQA #opr8i,rel
CBEQX #opr8i,rel
CBEQ oprx8,X+,rel
CBEQ ,X+,rel
CBEQ oprx8,SP,rel
Compare and...
CLC
Clear Carry Bit (C ← 0)
INH
98
1
p
–– – – – 0
CLI
Clear Interrupt Mask Bit (I ← 0)
INH
9A
1
p
–– 0 – – –
CLR opr8a
CLRA
CLRX
CLRH
CLR oprx8,X
CLR ,X
CLR oprx8,SP
Clear
DIR
INH
INH
INH
IX1
IX
SP1
3F dd
4F
5F
8C
6F ff
7F
9E 6F ff
5
1
1
1
5
4
6
rfwpp
p
p
p
rfwpp
rfwp
prfwpp
0– – 0 1 –
Branch if (A) = (M)
Branch if (A) = (M)
Branch if (X) = (M)
Branch if (A) = (M)
Branch if (A) = (M)
Branch if (A) = (M)
M ← $00
A ← $00
X ← $00
H ← $00
M ← $00
M ← $00
M ← $00
DIR
IMM
IMM
IX1+
IX+
SP1
31
41
51
61
71
9E 61
dd
ii
ii
ff
rr
ff
rr
rr
rr
rr
rr
MC9S08JM16 Series Data Sheet, Rev. 2
110
Freescale Semiconductor
Chapter 7 Central Processor Unit (S08CPUV2)
CMP
CMP
CMP
CMP
CMP
CMP
CMP
CMP
#opr8i
opr8a
opr16a
oprx16,X
oprx8,X
,X
oprx16,SP
oprx8,SP
Operation
Compare Accumulator with Memory
A–M
(CCR Updated But Operands Not Changed)
Object Code
IMM
DIR
EXT
IX2
IX1
IX
SP2
SP1
A1
B1
C1
D1
E1
F1
9E D1
9E E1
ii
dd
hh ll
ee ff
ff
ee ff
ff
Cycles
Source
Form
Address
Mode
Table 7-2. . Instruction Set Summary (Sheet 4 of 9)
Cyc-by-Cyc
Details
Affect
on CCR
VH I N Z C
2
3
4
4
3
3
5
4
pp
rpp
prpp
prpp
rpp
rfp
pprpp
prpp
– –
COM opr8a
COMA
COMX
COM oprx8,X
COM ,X
COM oprx8,SP
Complement
M ← (M)= $FF – (M)
(One’s Complement) A ← (A) = $FF – (A)
X ← (X) = $FF – (X)
M ← (M) = $FF – (M)
M ← (M) = $FF – (M)
M ← (M) = $FF – (M)
DIR
INH
INH
IX1
IX
SP1
33 dd
43
53
63 ff
73
9E 63 ff
5
1
1
5
4
6
rfwpp
p
p
rfwpp
rfwp
prfwpp
0– –
CPHX opr16a
CPHX #opr16i
CPHX opr8a
CPHX oprx8,SP
Compare Index Register (H:X) with Memory
(H:X) – (M:M + $0001)
(CCR Updated But Operands Not Changed)
EXT
IMM
DIR
SP1
3E
65
75
9E F3
hh ll
jj kk
dd
ff
6
3
5
6
prrfpp
ppp
rrfpp
prrfpp
– –
Compare X (Index Register Low) with
Memory
X–M
(CCR Updated But Operands Not Changed)
IMM
DIR
EXT
IX2
IX1
IX
SP2
SP1
A3
B3
C3
D3
E3
F3
9E D3
9E E3
ii
dd
hh ll
ee ff
ff
2
3
4
4
3
3
5
4
pp
rpp
prpp
prpp
rpp
rfp
pprpp
prpp
– –
1
p
U– –
7
4
4
7
6
8
rfwpppp
fppp
fppp
rfwpppp
rfwppp
prfwpppp
–– – – – –
CPX
CPX
CPX
CPX
CPX
CPX
CPX
CPX
#opr8i
opr8a
opr16a
oprx16,X
oprx8,X
,X
oprx16,SP
oprx8,SP
DAA
Decimal Adjust Accumulator
After ADD or ADC of BCD Values
INH
72
DBNZ opr8a,rel
DBNZA rel
DBNZX rel
DBNZ oprx8,X,rel
DBNZ ,X,rel
DBNZ oprx8,SP,rel
DIR
INH
Decrement A, X, or M and Branch if Not Zero
INH
(if (result) ≠ 0)
IX1
DBNZX Affects X Not H
IX
SP1
3B
4B
5B
6B
7B
9E 6B
DEC opr8a
DECA
DECX
DEC oprx8,X
DEC ,X
DEC oprx8,SP
Decrement
Divide
A ← (H:A)÷(X); H ← Remainder
DIV
EOR
EOR
EOR
EOR
EOR
EOR
EOR
EOR
M ← (M) – $01
A ← (A) – $01
X ← (X) – $01
M ← (M) – $01
M ← (M) – $01
M ← (M) – $01
#opr8i
opr8a
opr16a
oprx16,X
oprx8,X
,X
oprx16,SP
oprx8,SP
Exclusive OR Memory with Accumulator
A ← (A ⊕ M)
ee ff
ff
dd rr
rr
rr
ff rr
rr
ff rr
DIR
INH
INH
IX1
IX
SP1
3A dd
4A
5A
6A ff
7A
9E 6A ff
5
1
1
5
4
6
rfwpp
p
p
rfwpp
rfwp
prfwpp
– –
INH
52
6
fffffp
–– – –
IMM
DIR
EXT
IX2
IX1
IX
SP2
SP1
A8
B8
C8
D8
E8
F8
9E D8
9E E8
2
3
4
4
3
3
5
4
pp
rpp
prpp
prpp
rpp
rfp
pprpp
prpp
0– –
ii
dd
hh ll
ee ff
ff
ee ff
ff
1
–
–
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
111
Chapter 7 Central Processor Unit (S08CPUV2)
INC opr8a
INCA
INCX
INC oprx8,X
INC ,X
INC oprx8,SP
Operation
Increment
M ← (M) + $01
A ← (A) + $01
X ← (X) + $01
M ← (M) + $01
M ← (M) + $01
M ← (M) + $01
Object Code
Cycles
Source
Form
Address
Mode
Table 7-2. . Instruction Set Summary (Sheet 5 of 9)
Cyc-by-Cyc
Details
Affect
on CCR
VH I N Z C
DIR
INH
INH
IX1
IX
SP1
3C dd
4C
5C
6C ff
7C
9E 6C ff
5
1
1
5
4
6
rfwpp
p
p
rfwpp
rfwp
prfwpp
BC
CC
DC
EC
FC
dd
hh ll
ee ff
ff
3
4
4
3
3
ppp
pppp
pppp
ppp
ppp
–– – – – –
– –
–
JMP
JMP
JMP
JMP
JMP
opr8a
opr16a
oprx16,X
oprx8,X
,X
Jump
PC ← Jump Address
DIR
EXT
IX2
IX1
IX
JSR
JSR
JSR
JSR
JSR
opr8a
opr16a
oprx16,X
oprx8,X
,X
Jump to Subroutine
PC ← (PC) + n (n = 1, 2, or 3)
Push (PCL); SP ← (SP) – $0001
Push (PCH); SP ← (SP) – $0001
PC ← Unconditional Address
DIR
EXT
IX2
IX1
IX
BD
CD
DD
ED
FD
dd
hh ll
ee ff
ff
5
6
6
5
5
ssppp
pssppp
pssppp
ssppp
ssppp
–– – – – –
LDA
LDA
LDA
LDA
LDA
LDA
LDA
LDA
#opr8i
opr8a
opr16a
oprx16,X
oprx8,X
,X
oprx16,SP
oprx8,SP
Load Accumulator from Memory
A ← (M)
IMM
DIR
EXT
IX2
IX1
IX
SP2
SP1
A6
B6
C6
D6
E6
F6
9E D6
9E E6
ii
dd
hh ll
ee ff
ff
2
3
4
4
3
3
5
4
pp
rpp
prpp
prpp
rpp
rfp
pprpp
prpp
0– –
–
Load Index Register (H:X)
H:X ← (M:M + $0001)
IMM
DIR
EXT
IX
IX2
IX1
SP1
jj kk
dd
hh ll
9E
9E
9E
9E
45
55
32
AE
BE
CE
FE
3
4
5
5
6
5
5
ppp
rrpp
prrpp
prrfp
pprrpp
prrpp
prrpp
0– –
–
Load X (Index Register Low) from Memory
X ← (M)
IMM
DIR
EXT
IX2
IX1
IX
SP2
SP1
AE
BE
CE
DE
EE
FE
9E DE
9E EE
ii
dd
hh ll
ee ff
ff
2
3
4
4
3
3
5
4
pp
rpp
prpp
prpp
rpp
rfp
pprpp
prpp
0– –
–
DIR
INH
INH
IX1
IX
SP1
38 dd
48
58
68 ff
78
9E 68 ff
5
1
1
5
4
6
rfwpp
p
p
rfwpp
rfwp
prfwpp
–
DIR
INH
INH
IX1
IX
SP1
34 dd
44
54
64 ff
74
9E 64 ff
5
1
1
5
4
6
rfwpp
p
p
rfwpp
rfwp
prfwpp
– – 0
LDHX
LDHX
LDHX
LDHX
LDHX
LDHX
LDHX
LDX
LDX
LDX
LDX
LDX
LDX
LDX
LDX
#opr16i
opr8a
opr16a
,X
oprx16,X
oprx8,X
oprx8,SP
#opr8i
opr8a
opr16a
oprx16,X
oprx8,X
,X
oprx16,SP
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
Logical Shift Left
C
0
b7
b0
(Same as ASL)
Logical Shift Right
0
C
b7
b0
ee ff
ff
ee ff
ff
ff
ee ff
ff
–
MC9S08JM16 Series Data Sheet, Rev. 2
112
Freescale Semiconductor
Chapter 7 Central Processor Unit (S08CPUV2)
Operation
Object Code
MOV opr8a,opr8a
MOV opr8a,X+
MOV #opr8i,opr8a
MOV ,X+,opr8a
Move
(M)destination ← (M)source
In IX+/DIR and DIR/IX+ Modes,
H:X ← (H:X) + $0001
DIR/DIR
DIR/IX+
IMM/DIR
IX+/DIR
4E
5E
6E
7E
MUL
Unsigned multiply
X:A ← (X) × (A)
INH
NEG opr8a
NEGA
NEGX
NEG oprx8,X
NEG ,X
NEG oprx8,SP
Negate
M ← – (M) = $00 – (M)
(Two’s Complement) A ← – (A) = $00 – (A)
X ← – (X) = $00 – (X)
M ← – (M) = $00 – (M)
M ← – (M) = $00 – (M)
M ← – (M) = $00 – (M)
NOP
NSA
ORA
ORA
ORA
ORA
ORA
ORA
ORA
ORA
#opr8i
opr8a
opr16a
oprx16,X
oprx8,X
,X
oprx16,SP
oprx8,SP
Cycles
Source
Form
Address
Mode
Table 7-2. . Instruction Set Summary (Sheet 6 of 9)
Cyc-by-Cyc
Details
Affect
on CCR
VH I N Z C
5
5
4
5
rpwpp
rfwpp
pwpp
rfwpp
0– –
42
5
ffffp
–0 – – – 0
DIR
INH
INH
IX1
IX
SP1
30 dd
40
50
60 ff
70
9E 60 ff
5
1
1
5
4
6
rfwpp
p
p
rfwpp
rfwp
prfwpp
No Operation — Uses 1 Bus Cycle
INH
9D
1
p
–– – – – –
Nibble Swap Accumulator
A ← (A[3:0]:A[7:4])
INH
62
1
p
–– – – – –
Inclusive OR Accumulator and Memory
A ← (A) | (M)
IMM
DIR
EXT
IX2
IX1
IX
SP2
SP1
AA
BA
CA
DA
EA
FA
9E DA
9E EA
2
3
4
4
3
3
5
4
pp
rpp
prpp
prpp
rpp
rfp
pprpp
prpp
0– –
dd dd
dd
ii dd
dd
ii
dd
hh ll
ee ff
ff
ee ff
ff
–
–
–
–
PSHA
Push Accumulator onto Stack
Push (A); SP ← (SP) – $0001
INH
87
2
sp
–– – – – –
PSHH
Push H (Index Register High) onto Stack
Push (H); SP ← (SP) – $0001
INH
8B
2
sp
–– – – – –
PSHX
Push X (Index Register Low) onto Stack
Push (X); SP ← (SP) – $0001
INH
89
2
sp
–– – – – –
PULA
Pull Accumulator from Stack
SP ← (SP + $0001); Pull (A)
INH
86
3
ufp
–– – – – –
PULH
Pull H (Index Register High) from Stack
SP ← (SP + $0001); Pull (H)
INH
8A
3
ufp
–– – – – –
PULX
Pull X (Index Register Low) from Stack
SP ← (SP + $0001); Pull (X)
INH
88
3
ufp
–– – – – –
DIR
INH
INH
IX1
IX
SP1
39 dd
49
59
69 ff
79
9E 69 ff
5
1
1
5
4
6
rfwpp
p
p
rfwpp
rfwp
prfwpp
–
–
DIR
INH
INH
IX1
IX
SP1
36 dd
46
56
66 ff
76
9E 66 ff
5
1
1
5
4
6
rfwpp
p
p
rfwpp
rfwp
prfwpp
–
–
ROL opr8a
ROLA
ROLX
ROL oprx8,X
ROL ,X
ROL oprx8,SP
Rotate Left through Carry
ROR opr8a
RORA
RORX
ROR oprx8,X
ROR ,X
ROR oprx8,SP
Rotate Right through Carry
C
b7
b0
C
b7
b0
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
113
Chapter 7 Central Processor Unit (S08CPUV2)
Operation
Object Code
Cycles
Source
Form
Address
Mode
Table 7-2. . Instruction Set Summary (Sheet 7 of 9)
Cyc-by-Cyc
Details
VH I N Z C
RSP
Reset Stack Pointer (Low Byte)
SPL ← $FF
(High Byte Not Affected)
INH
9C
1
p
RTI
Return from Interrupt
SP ← (SP) + $0001;
SP ← (SP) + $0001;
SP ← (SP) + $0001;
SP ← (SP) + $0001;
SP ← (SP) + $0001;
INH
80
9
uuuuufppp
RTS
Return from Subroutine
SP ← SP + $0001; Pull (PCH)
SP ← SP + $0001; Pull (PCL)
INH
81
5
ufppp
Subtract with Carry
A ← (A) – (M) – (C)
IMM
DIR
EXT
IX2
IX1
IX
SP2
SP1
A2
B2
C2
D2
E2
F2
9E D2
9E E2
2
3
4
4
3
3
5
4
pp
rpp
prpp
prpp
rpp
rfp
pprpp
prpp
SBC
SBC
SBC
SBC
SBC
SBC
SBC
SBC
#opr8i
opr8a
opr16a
oprx16,X
oprx8,X
,X
oprx16,SP
oprx8,SP
Pull (CCR)
Pull (A)
Pull (X)
Pull (PCH)
Pull (PCL)
ii
dd
hh ll
ee ff
ff
ee ff
ff
Affect
on CCR
–– – – – –
–– – – – –
–
–
SEC
Set Carry Bit
(C ← 1)
INH
99
1
p
–– – – – 1
SEI
Set Interrupt Mask Bit
(I ← 1)
INH
9B
1
p
–– 1 – – –
Store Accumulator in Memory
M ← (A)
DIR
EXT
IX2
IX1
IX
SP2
SP1
B7
C7
D7
E7
F7
9E D7
9E E7
wpp
pwpp
pwpp
wpp
wp
ppwpp
pwpp
0–
–
–
ee ff
ff
3
4
4
3
2
5
4
35 dd
96 hh ll
9E FF ff
4
5
5
wwpp
pwwpp
pwwpp
0–
–
–
2
fp...
–– 0 – – –
3
4
4
3
2
5
4
wpp
pwpp
pwpp
wpp
wp
ppwpp
pwpp
0–
STA
STA
STA
STA
STA
STA
STA
opr8a
opr16a
oprx16,X
oprx8,X
,X
oprx16,SP
oprx8,SP
STHX opr8a
STHX opr16a
STHX oprx8,SP
Store H:X (Index Reg.)
(M:M + $0001) ← (H:X)
DIR
EXT
SP1
STOP
Enable Interrupts: Stop Processing
Refer to MCU Documentation
I bit ← 0; Stop Processing
INH
8E
Store X (Low 8 Bits of Index Register)
in Memory
M ← (X)
DIR
EXT
IX2
IX1
IX
SP2
SP1
BF
CF
DF
EF
FF
9E DF
9E EF
STX
STX
STX
STX
STX
STX
STX
opr8a
opr16a
oprx16,X
oprx8,X
,X
oprx16,SP
oprx8,SP
dd
hh ll
ee ff
ff
dd
hh ll
ee ff
ff
ee ff
ff
–
–
MC9S08JM16 Series Data Sheet, Rev. 2
114
Freescale Semiconductor
Chapter 7 Central Processor Unit (S08CPUV2)
SUB
SUB
SUB
SUB
SUB
SUB
SUB
SUB
#opr8i
opr8a
opr16a
oprx16,X
oprx8,X
,X
oprx16,SP
oprx8,SP
Operation
Object Code
IMM
DIR
EXT
IX2
IX1
IX
SP2
SP1
A0
B0
C0
D0
E0
F0
9E D0
9E E0
SWI
Software Interrupt
PC ← (PC) + $0001
Push (PCL); SP ← (SP) – $0001
Push (PCH); SP ← (SP) – $0001
Push (X); SP ← (SP) – $0001
Push (A); SP ← (SP) – $0001
Push (CCR); SP ← (SP) – $0001
I ← 1;
PCH ← Interrupt Vector High Byte
PCL ← Interrupt Vector Low Byte
INH
TAP
Transfer Accumulator to CCR
CCR ← (A)
TAX
TPA
TST opr8a
TSTA
TSTX
TST oprx8,X
TST ,X
TST oprx8,SP
Cycles
Source
Form
Address
Mode
Table 7-2. . Instruction Set Summary (Sheet 8 of 9)
Cyc-by-Cyc
Details
Affect
on CCR
VH I N Z C
2
3
4
4
3
3
5
4
pp
rpp
prpp
prpp
rpp
rfp
pprpp
prpp
83
11
sssssvvfppp
INH
84
1
p
Transfer Accumulator to X (Index Register
Low)
X ← (A)
INH
97
1
p
–– – – – –
Transfer CCR to Accumulator
A ← (CCR)
INH
85
1
p
–– – – – –
DIR
INH
INH
IX1
IX
SP1
3D dd
4D
5D
6D ff
7D
9E 6D ff
4
1
1
4
3
5
rfpp
p
p
rfpp
rfp
prfpp
0–
Subtract
A ← (A) – (M)
Test for Negative or Zero
(M) – $00
(A) – $00
(X) – $00
(M) – $00
(M) – $00
(M) – $00
ii
dd
hh ll
ee ff
ff
ee ff
ff
–
–
–– 1 – – –
–
–
TSX
Transfer SP to Index Reg.
H:X ← (SP) + $0001
INH
95
2
fp
–– – – – –
TXA
Transfer X (Index Reg. Low) to Accumulator
A ← (X)
INH
9F
1
p
–– – – – –
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
115
Chapter 7 Central Processor Unit (S08CPUV2)
Operation
Object Code
Cycles
Source
Form
Address
Mode
Table 7-2. . Instruction Set Summary (Sheet 9 of 9)
Cyc-by-Cyc
Details
Affect
on CCR
VH I N Z C
TXS
Transfer Index Reg. to SP
SP ← (H:X) – $0001
INH
94
2
fp
–– – – – –
WAIT
Enable Interrupts; Wait for Interrupt
I bit ← 0; Halt CPU
INH
8F
2+
fp...
–– 0 – – –
Source Form: Everything in the source forms columns, except expressions in italic characters, is literal information which must appear in
the assembly source file exactly as shown. The initial 3- to 5-letter mnemonic and the characters (# , ( ) and +) are always a 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 direct-page address ($00xx).
opr16a Any label or expression that evaluates to a 16-bit address.
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, used for indexed addressing.
rel
Any label or expression that refers to an address that is within –128 to +127 locations from the start of the next instruction.
Operation Symbols:
A
Accumulator
CCR Condition code register
H
Index register high byte
M
Memory location
n
Any bit
opr
Operand (one or two bytes)
PC
Program counter
PCH Program counter high byte
PCL Program counter low byte
rel
Relative program counter offset byte
SP
Stack pointer
SPL Stack pointer low byte
X
Index register low byte
&
Logical AND
|
Logical OR
⊕
Logical EXCLUSIVE OR
()
Contents of
+
Add
–
Subtract, Negation (two’s complement)
×
Multiply
÷
Divide
#
Immediate value
←
Loaded with
:
Concatenated with
Addressing Modes:
DIR Direct addressing mode
EXT Extended addressing mode
IMM Immediate addressing mode
INH Inherent addressing mode
IX
Indexed, no offset addressing mode
IX1
Indexed, 8-bit offset addressing mode
IX2
Indexed, 16-bit offset addressing mode
IX+
Indexed, no offset, post increment addressing mode
IX1+ Indexed, 8-bit offset, post increment addressing mode
REL Relative addressing mode
SP1 Stack pointer, 8-bit offset addressing mode
SP2 Stack pointer 16-bit offset addressing mode
CCR Bits:
V
Overflow bit
H
Half-carry bit
I
Interrupt mask
N
Negative bit
Z
Zero bit
C
Carry/borrow bit
CCR Effects:
Set or cleared
–
Not affected
U
Undefined
Cycle-by-Cycle Codes:
f
Free cycle. This indicates a cycle where the CPU
does not require use of the system buses. An f
cycle is always one cycle of the system bus clock
and is always a read cycle.
p
Progryam fetch; read from next consecutive
location in program memory
r
Read 8-bit operand
s
Push (write) one byte onto stack
u
Pop (read) one byte from stack
v
Read vector from $FFxx (high byte first)
w
Write 8-bit operand
MC9S08JM16 Series Data Sheet, Rev. 2
116
Freescale Semiconductor
Chapter 7 Central Processor Unit (S08CPUV2)
Table 7-3. Opcode Map (Sheet 1 of 2)
Bit-Manipulation
Branch
00
5 10
5 20
3 30
BRSET0
3
01
BRCLR0
3
02
BRSET2
3
05
BRSET3
3
07
BRCLR4
3
0A
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
Inherent
Immediate
Direct
Extended
DIR to DIR
IX+ to DIR
DBNZ
INC
REL 2
3 3D
TST
REL 2
3 3E
BIL
BIH
CLR
REL 2
REL
IX
IX1
IX2
IMD
DIX+
DIR 1
INH 1
Relative
Indexed, No Offset
Indexed, 8-Bit Offset
Indexed, 16-Bit Offset
IMM to DIR
DIR to IX+
ROL
INH 2
1 6A
DEC
DBNZ
DEC
DBNZ
IX1 2
5 7C
INC
IX1 1
4 7D
TST
INH 2
5 6E
MOV
CLRX
IX1 1
CLR
ADD
INH 2
1
BSR
Page 2
WAIT
INH 1
2
5 BD
ADD
DIR 3
3 CC
LDX
2
1 AF
TXA
INH 2
LDX
IMM 2
2 BF
AIX
Stack Pointer, 8-Bit Offset
Stack Pointer, 16-Bit Offset
Indexed, No Offset with
Post Increment
Indexed, 1-Byte Offset with
Post Increment
DIR 3
Opcode in
Hexadecimal F0
Number of Bytes 1
EXT 3
4 DF
STX
EXT 3
EOR
ADC
IX2 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
2
IX1 1
3 F9
IX2 2
4 EE
LDX
IX
3
LDA
IX1 1
3 F8
IX2 2
6 ED
JSR
EXT 3
4 DE
LDX
DIR 3
3 CF
STX
IMM 2
JSR
DIR 3
3 CE
BIT
STA
IX2 2
4 EC
JMP
EXT 3
6 DD
IX
3
IX1 1
3 F7
IX2 2
4 EB
ADD
EXT 3
4 DC
JMP
DIR 3
5 CD
JSR
REL 2
2 BE
EXT 3
4 DB
AND
LDA
IX2 2
4 EA
ORA
IX
3
IX1 1
3 F6
IX2 2
4 E9
ADC
CPX
BIT
IX2 2
4 E8
EOR
IX
3
IX1 1
3 F5
IX2 2
4 E7
EXT 3
4 DA
ORA
JMP
INH 2
AE
INH
2+ 9F
ADC
DIR 3
3 CB
ADD
IMM 2
BC
INH
1 AD
NOP
IX 1
IMM 2
2 BB
AND
LDA
EXT 3
4 D9
IX
3
SBC
IX1 1
3 F4
STA
EOR
DIR 3
3 CA
ORA
RSP
1
2+ 9E
STOP
ADC
CPX
IX2 2
4 E6
EXT 3
4 D8
CMP
IX1 1
3 F3
BIT
STA
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
SBC
IX2 2
4 E5
EXT 3
4 D7
DIR 3
3 C8
IMM 2
2 B9
INH 2
1 AA
CLI
TST
IX1 1
4 7E
MOV
SEC
INH 1
3 9A
PSHH
IX 1
4 8C
EOR
INH 2
1 A9
PULH
IX 1
6 8B
INC
INH 2
1 6D
PSHX
IX 1
4 8A
IX1 1
7 7B
INH 3
1 6C
IX1+
ROL
CLC
INH 1
2 99
AND
IX
3
IX1 1
3 F2
IX2 2
4 E4
EXT 3
4 D6
LDA
STA
IMM 2
2 B8
CPX
EXT 3
4 D5
DIR 3
3 C7
CMP
IX2 2
4 E3
BIT
LDA
AIS
INH 2
1 A8
AND
DIR 3
3 C6
IMM 2
2 B7
TAX
INH 1
3 98
PULX
IX 1
4 89
IX1 1
5 7A
INH 2
4 6B
SP1
SP2
IX+
LSL
IX1 1
5 79
LDA
SBC
3
SUB
IX1 1
3 F1
IX2 2
4 E2
EXT 3
4 D4
BIT
IMM 2
2 B6
EXT 2
1 A7
CPX
DIR 3
3 C5
BIT
STHX
INH 3
2 97
AND
CMP
EXT 3
4 D3
DIR 3
3 C4
IMM 2
2 B5
INH 2
5 A6
PSHA
IX 1
4 88
LSL
INH 2
1 69
DD 2
DIX+ 3
1 5F
1 6F
CLRA
ASR
IX1 1
5 78
TSTX
INH 1
5 5E
MOV
EXT 3
5 4F
ASR
INH 2
1 68
PULA
CPX
AND
TSX
INH 1
3 96
SBC
3 F0
SUB
IX2 2
4 E1
EXT 3
4 D2
DIR 3
3 C3
IMM 2
2 B4
INH 2
2 A5
TPA
IX 1
4 87
CPX
TXS
CMP
SBC
SUB
EXT 3
4 D1
DIR 3
3 C2
IMM 2
2 B3
REL 2
2 A4
INH 1
1 95
DIR 1
4 86
IX1 1
5 77
INCX
INH 1
1 5D
TSTA
DIR 1
6 4E
CPHX
REL 3
3 3F
INCA
DIR 1
4 4D
INH 2
1 67
DBNZX
INH 2
1 5C
CPHX
ROR
BLE
TAP
CMP
SBC
SUB
DIR 3
3 C1
IMM 2
2 B2
REL 2
3 A3
INH 2
1 94
IX 1
5 85
IMM 2
5 76
ROR
DECX
INH 1
4 5B
DBNZA
DIR 2
5 4C
CPHX
ROLX
INH 1
1 5A
DECA
DIR 1
7 4B
REL 3
3 3C
BMS
DIR 2
5 2E
DIR 2
DEC
BMC
DIR 2
5 2D
ROLA
DIR 1
5 4A
REL 2
3 3B
BMI
DIR 2
5 2C
BCLR7
DIR 2
ROL
LSR
CMP
BGT
SWI
SUB
IMM 2
2 B1
REL 2
3 A2
INH 2
11 93
IX 1
4 84
IX1 1
3 75
DIR 3
1 66
BGND
COM
SUB
BLT
INH 2
5+ 92
Register/Memory
3 C0
4 D0
4 E0
2 B0
REL 2
3 A1
RTS
INH 1
4 83
LSR
LSLX
INH 1
1 59
DAA
3 A0
BGE
INH 2
6 91
IX+ 1
1 82
IX1 1
5 74
INH 2
4 65
ASRX
INH 1
1 58
LSLA
DIR 1
5 49
REL 2
3 3A
DIR 2
5 2B
BSET7
DIR 2
5 1F
LSL
BHCS
BPL
ASRA
DIR 1
5 48
REL 2
3 39
DIR 2
5 2A
BCLR6
DIR 2
5 1E
ASR
COM
RORX
INH 1
1 57
CBEQ
INH 1
5 73
INH 2
1 64
LDHX
IMM 2
1 56
RORA
DIR 1
5 47
BHCC
DIR 2
5 29
BSET6
DIR 2
5 1D
ROR
INH 1
1 63
RTI
IX 1
5 81
IX1+ 2
1 72
LSRX
INH 1
3 55
NEG
NSA
COMX
INH 1
1 54
LDHX
DIR 3
5 46
REL 2
3 38
INH 1
1 53
LSRA
DIR 1
4 45
STHX
BEQ
DIR 2
5 28
BCLR5
DIR 2
5 1C
LSR
CBEQ
Control
9 90
4 80
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
DIR 2
5 27
BCLR4
DIR 2
5 1A
COM
REL 2
3 36
BNE
MUL
5 70
NEG
INH 2
4 61
CBEQX
IMM 3
5 52
EXT 1
5 43
REL 2
3 35
BCS
CBEQA
LDHX
NEGX
INH 1
4 51
DIR 3
5 42
BCC
DIR 2
5 26
BSET4
DIR 2
5 19
CBEQ
REL 2
3 34
DIR 2
5 25
BCLR3
DIR 2
5 18
BRSET4
3
09
BLS
NEGA
DIR 1
5 41
REL 3
3 33
DIR 2
5 24
BSET3
DIR 2
5 17
BRCLR3
3
08
DIR 2
5 23
BCLR2
DIR 2
5 16
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 40
REL 2
3 31
BSET1
DIR 2
5 13
BRCLR1
3
04
BRA
DIR 2
5 21
BCLR0
DIR 2
5 12
BRSET1
3
03
BSET0
DIR 2
5 11
Read-Modify-Write
1 50
1 60
IX
3
LDX
IX
2
STX
IX
3 HCS08 Cycles
Instruction Mnemonic
IX Addressing Mode
SUB
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
117
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 9EE0
6
NEG
SUB
3
SP1
9E61
6
CBEQ
4
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
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
MC9S08JM16 Series Data Sheet, Rev. 2
118
Freescale Semiconductor
Chapter 8
Keyboard Interrupt (S08KBIV2)
8.1
Introduction
The MC9S08JM16 series have one KBI module with seven keyboard interrupt inputs. See Chapter 2,
“Pins and Connections,” for more information about the logic and hardware aspects of these pins.
NOTE
MC9S08JM16 series devices operate at a higher voltage range (2.7 V to
5.5 V) and do not include stop1 mode. Therefore, please disregard
references to stop1.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
119
Keyboard Interrupt (KBI) ModuleChapter 8 Keyboard Interrupt (S08KBIV2)
IRQ/TPMCLK
USB SIE
CPU
HCS08 SYSTEM CONTROL
RESETS AND INTERRUPTS
MODES OF OPERATION
POWER MANAGEMENT
FULL SPEED
USB
USB ENDPOINT TRANSCEIVER
RAM
8-/16-BIT
SERIAL PERIPHERAL
INTERFACE MODULE (SPI2)
SERIAL COMMUNICATIONS
INTERFACE MODULE (SCI2)
COP
IRQ
LVD
IIC MODULE (IIC)
VDDAD
USER FLASH (IN BYTES)
MC9S08JM16 = 16,384
MC9S08JM8 = 8,192
SS2
SPSCK2
MOSI2
MISO2
RxD2
TxD2
SDA
SCL
6
ANALOG COMPARATOR
(ACMP)
ACMP+
8-/16-BIT
SERIAL PERIPHERAL
INTERFACE MODULE (SPI1)
SPSCK1
ACMPO
VSS
VUSB33
SYSTEM
VOLTAGE
REGULATOR
INTERFACE MODULE (SCI1)
2-CHANNEL TIMER/PWM
MODULE (TPM2)
REAL-TIME COUNTER
(RTC)
7-BIT KEYBOARD
INTERRUPT MODULE (KBI)
PTE5/MOSI1
MISO1
PTE4/MISO1
PORT E
TPMCLK
TPM1CH1
2
PTE3/TPM1CH1
PTE2/TPM1CH0
RxD1
TxD1
PTE1/RxD1
PTE0/TxD1
TPMCLK
TPM2CH1
TPM2CH0
PTF6
PTF5/TPM2CH1
PTF4/TPM2CH0
KBIPx
USB 3.3 V VOLTAGE REGULATOR
PTE6/SPSCK1
MOSI1
TPM1CH0
TPM1CHx
PTD2/KBIP2/ACMPO
PTE7/SS1
KBIPx
EXTAL
XTAL
PORT F
VDD
LOW-POWER OSCILLATOR
SERIAL COMMUNICATIONS
PTC5/RxD2
PTC4
PTC3/TxD2
PTC2
PTD1/ADP9/ACMP–
PTD0/ADP8/ACMP+
3
PTF1/TPM1CH3
PTF0/TPM1CH2
4
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 must not be driven above VDD.
4. Pin contains integrated pullup device.
5. When pin functions as KBI (KBIPEn = 1) and associated pin is configured to enable the
pullup device, KBEDGn can be used to reconfigure the pullup as a pulldown device.
PTG5/EXTAL
PORT G
VSSOSC
MODULE (TPM1)
PTB5/KBIP5/ADP5
PTB4/KBIP4/ADP4
PTB3/SS2/ADP3
PTB2/SPSCK2/ADP2
PTB1/MOSI2/ADP1
PTB0/MISO2/ADP0
PTD7
ACMP–
4-CHANNEL TIMER/PWM
MULTI-PURPOSE CLOCK
GENERATOR (MCG)
PTA5, PTA0
2
SS1
USER RAM (IN BYTES)
1024
2
PTC1/SDA
PTC0/SCL
PORT D
8-CHANNEL, 12-BIT
ANALOG-TO-DIGITAL
CONVERTER (ADC)
VSSAD
VREFL
VREFH
PORT B
BDC
PORT C
RESET
PORT A
HCS08 CORE
BKGD/MS
USBDP
USBDN
ON-CHIP ICE AND
DEBUG MODULE (DBG)
PTG4/XTAL
PTG3/KBIP7
PTG2/KBIP6
PTG1/KBIP1
PTG0/KBIP0
Figure 8-1. MC9S08JM16 Series Block Diagram Highlighting KBI Block and Pins
MC9S08JM16 Series Data Sheet, Rev. 2
120
Freescale Semiconductor
Keyboard Interrupts (S08KBIV2)
8.1.1
Features
The KBI features include:
• Up to eight keyboard interrupt pins with individual pin enable bits.
• Each keyboard interrupt pin is programmable as falling edge (or rising edge) only, or both falling
edge and low level (or both rising edge and high level) interrupt sensitivity.
• One software enabled keyboard interrupt.
• Exit from low-power modes.
8.1.2
Modes of Operation
This section defines the KBI operation in wait, stop, and background debug modes.
8.1.2.1
KBI in Wait Mode
The KBI continues to operate in wait mode if enabled before executing the WAIT instruction. Therefore,
an enabled KBI pin (KBPEx = 1) can be used to bring the MCU out of wait mode if the KBI interrupt is
enabled (KBIE = 1).
8.1.2.2
KBI in Stop Modes
The KBI operates asynchronously in stop3 mode if enabled before executing the STOP instruction.
Therefore, an enabled KBI pin (KBPEx = 1) can be used to bring the MCU out of stop3 mode if the KBI
interrupt is enabled (KBIE = 1).
During either stop1 or stop2 mode, the KBI is disabled. In some systems, the pins associated with the KBI
may be sources of wakeup from stop1 or stop2, see the stop modes section in the Modes of Operation
chapter. Upon wake-up from stop1 or stop2 mode, the KBI module will be in the reset state.
8.1.2.3
KBI in Active Background Mode
When the microcontroller is in active background mode, the KBI will continue to operate normally.
8.1.3
Block Diagram
The block diagram for the keyboard interrupt module is shown Figure 8-2.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
121
Keyboard Interrupts (S08KBIV2)
BUSCLK
KBACK
VDD
1
KBIP0
0
S
RESET
KBF
D CLR Q
KBIPE0
SYNCHRONIZER
CK
KBEDG0
KEYBOARD
INTERRUPT FF
1
KBIPn
0
S
STOP
STOP BYPASS
KBI
INTERRUPT
REQUEST
KBMOD
KBIPEn
KBIE
KBEDGn
Figure 8-2. KBI Block Diagram
8.2
External Signal Description
The KBI input pins can be used to detect either falling edges, or both falling edge and low level interrupt
requests. The KBI input pins can also be used to detect either rising edges, or both rising edge and high
level interrupt requests.
The signal properties of KBI are shown in Table 8-1.
Table 8-1. Signal Properties
Signal
Function
KBIPn
8.3
Keyboard interrupt pins
I/O
I
Register Definition
The KBI includes three registers:
• An 8-bit pin status and control register.
• An 8-bit pin enable register.
• An 8-bit edge select register.
Refer to the direct-page register summary in the Memory chapter for the absolute address assignments for
all KBI registers. This section refers to registers and control bits only by their names.
Some MCUs may have more than one KBI, so register names include placeholder characters to identify
which KBI is being referenced.
8.3.1
KBI Status and Control Register (KBISC)
KBISC contains the status flag and control bits, which are used to configure the KBI.
MC9S08JM16 Series Data Sheet, Rev. 2
122
Freescale Semiconductor
Keyboard Interrupts (S08KBIV2)
R
7
6
5
4
3
2
0
0
0
0
KBF
0
W
Reset:
1
0
KBIE
KBMOD
0
0
KBACK
0
0
0
0
0
0
= Unimplemented
Figure 8-3. KBI Status and Control Register
Table 8-2. KBISC Register Field Descriptions
Field
Description
7:4
Unused register bits, always read 0.
3
KBF
Keyboard Interrupt Flag — KBF indicates when a keyboard interrupt is detected. Writes have no effect on KBF.
0 No keyboard interrupt detected.
1 Keyboard interrupt detected.
2
KBACK
Keyboard Acknowledge — Writing a 1 to KBACK is part of the flag clearing mechanism. KBACK always reads
as 0.
1
KBIE
Keyboard Interrupt Enable — KBIE determines whether a keyboard interrupt is requested.
0 Keyboard interrupt request not enabled.
1 Keyboard interrupt request enabled.
0
KBMOD
8.3.2
Keyboard Detection Mode — KBMOD (along with the KBEDG bits) controls the detection mode of the keyboard
interrupt pins.0Keyboard detects edges only.
1 Keyboard detects both edges and levels.
KBI Pin Enable Register (KBIPE)
KBIPE contains the pin enable control bits.
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:
Figure 8-4. KBI Pin Enable Register
Table 8-3. KBIPE Register Field Descriptions
Field
7:0
KBIPEn
8.3.3
Description
Keyboard Pin Enables — Each of the KBIPEn bits enable the corresponding keyboard interrupt pin.
0 Pin not enabled as keyboard interrupt.
1 Pin enabled as keyboard interrupt.
KBI Edge Select Register (KBIES)
KBIES contains the edge select control bits.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
123
Keyboard Interrupts (S08KBIV2)
7
6
5
4
3
2
1
0
KBEDG7
KBEDG6
KBEDG5
KBEDG4
KBEDG3
KBEDG2
KBEDG1
KBEDG0
0
0
0
0
0
0
0
0
R
W
Reset:
Figure 8-5. KBI Edge Select Register
Table 8-4. KBIES Register Field Descriptions
Field
7:0
KBEDGn
8.4
Description
Keyboard Edge Selects — Each of the KBEDGn bits selects the falling edge/low level or rising edge/high level
function of the corresponding pin).
0 Falling edge/low level.
1 Rising edge/high level.
Functional Description
This on-chip peripheral module is called a keyboard interrupt (KBI) module because originally it was
designed to simplify the connection and use of row-column matrices of keyboard switches. However, these
inputs are also useful as extra external interrupt inputs and as an external means of waking the MCU from
stop or wait low-power modes.
The KBI module allows up to eight pins to act as additional interrupt sources. Writing to the KBIPEn bits
in the keyboard interrupt pin enable register (KBIPE) independently enables or disables each KBI pin.
Each KBI pin can be configured as edge sensitive or edge and level sensitive based on the KBMOD bit in
the keyboard interrupt status and control register (KBISC). Edge sensitive can be software programmed to
be either falling or rising; the level can be either low or high. The polarity of the edge or edge and level
sensitivity is selected using the KBEDGn bits in the keyboard interrupt edge select register (KBIES).
8.4.1
Edge Only Sensitivity
Synchronous logic is used to detect edges. A falling edge is detected when an enabled keyboard interrupt
(KBIPEn=1) 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 (the deasserted level) during one bus cycle and then a logic 1 (the asserted level) during the next
cycle.Before the first edge is detected, all enabled keyboard interrupt input signals must be at the
deasserted logic levels. After any edge is detected, all enabled keyboard interrupt input signals must return
to the deasserted level before any new edge can be detected.
A valid edge on an enabled KBI pin will set KBF in KBISC. If KBIE in KBISC is set, an interrupt request
will be presented to the CPU. Clearing of KBF is accomplished by writing a 1 to KBACK in KBISC.
8.4.2
Edge and Level Sensitivity
A valid edge or level on an enabled KBI pin will set KBF in KBISC. If KBIE in KBISC is set, an interrupt
request will be presented to the CPU. Clearing of KBF is accomplished by writing a 1 to KBACK in
MC9S08JM16 Series Data Sheet, Rev. 2
124
Freescale Semiconductor
Keyboard Interrupts (S08KBIV2)
KBISC provided all enabled keyboard inputs are at their deasserted levels. KBF will remain set if any
enabled KBI pin is asserted while attempting to clear by writing a 1 to KBACK.
8.4.3
KBI Pullup/Pulldown Resistors
The KBI pins can be configured to use an internal pullup/pulldown resistor using the associated I/O port
pullup enable register. If an internal resistor is enabled, the KBIES register is used to select whether the
resistor is a pullup (KBEDGn = 0) or a pulldown (KBEDGn = 1).
8.4.4
KBI Initialization
When a keyboard interrupt pin is first enabled it is possible to get a false keyboard interrupt flag. To
prevent a false interrupt request during keyboard initialization, the user must do the following:
1. Mask keyboard interrupts by clearing KBIE in KBISC.
2. Enable the KBI polarity by setting the appropriate KBEDGn bits in KBIES.
3. If using internal pullup/pulldown device, configure the associated pullup enable bits in PTxPE.
4. Enable the KBI pins by setting the appropriate KBIPEn bits in KBIPE.
5. Write to KBACK in KBISC to clear any false interrupts.
6. Set KBIE in KBISC to enable interrupts.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
125
Keyboard Interrupts (S08KBIV2)
MC9S08JM16 Series Data Sheet, Rev. 2
126
Freescale Semiconductor
Chapter 9
5 V Analog Comparator (S08ACMPV2)
9.1
Introduction
The analog comparator module (ACMP) provides a circuit for comparing two analog input voltages or for
comparing one analog input voltage to an internal reference voltage. The comparator circuit is designed to
operate across the full range of the supply voltage (rail to rail operation).
NOTE
MC9S08JM16 series devices operate at a higher voltage range (2.7 V to
5.5 V) and do not include stop1 mode. Therefore, please disregard
references to stop1.
9.1.1
ACMP Configuration Information
When using the bandgap reference voltage for input to ACMP+, the user must enable the bandgap buffer
by setting BGBE =1 in SPMSC1 see Section 5.7.7, “System Power Management Status and Control 1
Register (SPMSC1)”. For value of bandgap voltage reference see Appendix A.6, “DC Characteristics.”
9.1.2
ACMP/TPM Configuration Information
The ACMP module can be configured to connect the output of the analog comparator to TPM input capture
channel 0 by setting ACIC in SOPT2. With ACIC set, the TPM1CH0 pin is not available externally
regardless of the configuration of the TPM module.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
127
Chapter 9 5 V Analog Comparator (S08ACMPV2)
IRQ/TPMCLK
USB SIE
CPU
HCS08 SYSTEM CONTROL
RESETS AND INTERRUPTS
MODES OF OPERATION
POWER MANAGEMENT
FULL SPEED
USB
USB ENDPOINT TRANSCEIVER
RAM
8-/16-BIT
SERIAL PERIPHERAL
INTERFACE MODULE (SPI2)
SERIAL COMMUNICATIONS
INTERFACE MODULE (SCI2)
COP
IRQ
LVD
IIC MODULE (IIC)
VDDAD
USER FLASH (IN BYTES)
MC9S08JM16 = 16,384
MC9S08JM8 = 8,192
SS2
SPSCK2
MOSI2
MISO2
RxD2
TxD2
SDA
SCL
6
ANALOG COMPARATOR
(ACMP)
ACMP+
8-/16-BIT
SERIAL PERIPHERAL
INTERFACE MODULE (SPI1)
SPSCK1
ACMPO
VSS
VUSB33
SYSTEM
VOLTAGE
REGULATOR
INTERFACE MODULE (SCI1)
2-CHANNEL TIMER/PWM
MODULE (TPM2)
REAL-TIME COUNTER
(RTC)
7-BIT KEYBOARD
INTERRUPT MODULE (KBI)
PTE5/MOSI1
MISO1
PTE4/MISO1
PORT E
TPMCLK
TPM1CH1
2
PTE3/TPM1CH1
PTE2/TPM1CH0
RxD1
TxD1
PTE1/RxD1
PTE0/TxD1
TPMCLK
TPM2CH1
TPM2CH0
PTF6
PTF5/TPM2CH1
PTF4/TPM2CH0
KBIPx
USB 3.3 V VOLTAGE REGULATOR
PTE6/SPSCK1
MOSI1
TPM1CH0
TPM1CHx
PTD2/KBIP2/ACMPO
PTE7/SS1
KBIPx
EXTAL
XTAL
PORT F
VDD
LOW-POWER OSCILLATOR
SERIAL COMMUNICATIONS
PTC5/RxD2
PTC4
PTC3/TxD2
PTC2
PTD1/ADP9/ACMP–
PTD0/ADP8/ACMP+
3
PTF1/TPM1CH3
PTF0/TPM1CH2
4
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 must not be driven above VDD.
4. Pin contains integrated pullup device.
5. When pin functions as KBI (KBIPEn = 1) and associated pin is configured to enable the
pullup device, KBEDGn can be used to reconfigure the pullup as a pulldown device.
PTG5/EXTAL
PORT G
VSSOSC
MODULE (TPM1)
PTB5/KBIP5/ADP5
PTB4/KBIP4/ADP4
PTB3/SS2/ADP3
PTB2/SPSCK2/ADP2
PTB1/MOSI2/ADP1
PTB0/MISO2/ADP0
PTD7
ACMP–
4-CHANNEL TIMER/PWM
MULTI-PURPOSE CLOCK
GENERATOR (MCG)
PTA5, PTA0
2
SS1
USER RAM (IN BYTES)
1024
2
PTC1/SDA
PTC0/SCL
PORT D
8-CHANNEL, 12-BIT
ANALOG-TO-DIGITAL
CONVERTER (ADC)
VSSAD
VREFL
VREFH
PORT B
BDC
PORT C
RESET
PORT A
HCS08 CORE
BKGD/MS
USBDP
USBDN
ON-CHIP ICE AND
DEBUG MODULE (DBG)
PTG4/XTAL
PTG3/KBIP7
PTG2/KBIP6
PTG1/KBIP1
PTG0/KBIP0
Figure 9-1. MC9S08JM16 Series Block Diagram Highlighting ACMP Block and Pins
MC9S08JM16 Series Data Sheet, Rev. 2
128
Freescale Semiconductor
Analog Comparator (S08ACMPV2)
9.1.3
Features
The ACMP has the following features:
• Full rail to rail supply operation.
• Selectable interrupt on rising edge, falling edge, or either rising or falling edges of comparator
output.
• Option to compare to fixed internal bandgap reference voltage.
• Option to allow comparator output to be visible on a pin, ACMPO.
• Can operate in stop3 mode
9.1.4
Modes of Operation
This section defines the ACMP operation in wait, stop and background debug modes.
9.1.4.1
ACMP in Wait Mode
The ACMP continues to run in wait mode if enabled before executing the WAIT instruction. Therefore,
the ACMP can be used to bring the MCU out of wait mode if the ACMP interrupt, ACIE is enabled. For
lowest possible current consumption, the ACMP must be disabled by software if not required as an
interrupt source during wait mode.
9.1.4.2
9.1.4.2.1
ACMP in Stop Modes
Stop3 Mode Operation
The ACMP continues to operate in stop3 mode if enabled and compare operation remains active. If
ACOPE is enabled, comparator output operates as in the normal operating mode and comparator output is
placed onto the external pin. The MCU is brought out of stop when a compare event occurs and ACIE is
enabled; ACF flag sets accordingly.
If stop is exited with a reset, the ACMP will be put into its reset state.
9.1.4.2.2
Stop2 and Stop1 Mode Operation
During either stop2 and stop1 mode, the ACMP module will be fully powered down. Upon wake-up from
stop2 or stop1 mode, the ACMP module will be in the reset state.
9.1.4.3
ACMP in Active Background Mode
When the microcontroller is in active background mode, the ACMP will continue to operate normally.
9.1.5
Block Diagram
The block diagram for the Analog Comparator module is shown Figure 9-2.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
129
Analog Comparator (S08ACMPV2)
Internal Bus
Internal
Reference
ACMP
INTERRUPT
REQUEST
ACIE
ACBGS
Status & Control
Register
ACME
ACF
ACMP+
+
set ACF
ACMOD
ACOPE
Interrupt
Control
Comparator
ACMP–
ACMPO
Figure 9-2. Analog Comparator 5V (ACMP5) Block Diagram
9.2
External Signal Description
The ACMP has two analog input pins, ACMP+ and ACMP– and one digital output pin ACMPO. Each of
these pins can accept an input voltage that varies across the full operating voltage range of the MCU. As
shown in Figure 9-2, the ACMP– pin is connected to the inverting input of the comparator, and the
ACMP+ pin is connected to the comparator non-inverting input if ACBGS is a 0. As shown in Figure 9-2,
the ACMPO pin can be enabled to drive an external pin.
The signal properties of ACMP are shown in Table 9-1.
Table 9-1. Signal Properties
Signal
9.3
9.3.1
Function
I/O
ACMP–
Inverting analog input to the ACMP.
(Minus input)
I
ACMP+
Non-inverting analog input to the ACMP.
(Positive input)
I
ACMPO
Digital output of the ACMP.
O
Memory Map
Register Descriptions
The ACMP includes one register:
MC9S08JM16 Series Data Sheet, Rev. 2
130
Freescale Semiconductor
Analog Comparator (S08ACMPV2)
•
An 8-bit status and control register
Refer to the direct-page register summary in the memory section of this data sheet for the absolute address
assignments for all ACMP registers.This section refers to registers and control bits only by their names.
Some MCUs may have more than one ACMP, so register names include placeholder characters to identify
which ACMP is being referenced.
9.3.1.1
ACMP Status and Control Register (ACMPSC)
ACMPSC contains the status flag and control bits which are used to enable and configure the ACMP.
7
6
5
4
3
ACME
ACBGS
ACF
ACIE
0
0
0
0
R
2
1
0
ACO
ACOPE
ACMOD
W
Reset:
0
0
0
0
= Unimplemented
Figure 9-3. ACMP Status and Control Register
Table 9-2. ACMP Status and Control Register Field Descriptions
Field
7
ACME
Description
Analog Comparator Module Enable — ACME enables the ACMP module.
0 ACMP not enabled
1 ACMP is enabled
6
ACBGS
Analog Comparator Bandgap Select — ACBGS is used to select between the bandgap reference voltage or
the ACMP+ pin as the input to the non-inverting input of the analog comparatorr.
0 External pin ACMP+ selected as non-inverting input to comparator
1 Internal reference select as non-inverting input to comparator
Note: refer to this chapter introduction to verify if any other config bits are necessary to enable the bandgap
reference in the chip level.
5
ACF
Analog Comparator Flag — ACF is set when a compare event occurs. Compare events are defined by ACMOD.
ACF is cleared by writing a one to ACF.
0 Compare event has not occurred
1 Compare event has occurred
4
ACIE
Analog Comparator Interrupt Enable — ACIE enables the interrupt from the ACMP. When ACIE is set, an
interrupt will be asserted when ACF is set.
0 Interrupt disabled
1 Interrupt enabled
3
ACO
Analog Comparator Output — Reading ACO will return the current value of the analog comparator output. ACO
is reset to a 0 and will read as a 0 when the ACMP is disabled (ACME = 0).
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
131
Analog Comparator (S08ACMPV2)
Table 9-2. ACMP Status and Control Register Field Descriptions (continued)
Field
Description
2
ACOPE
Analog Comparator Output Pin Enable — ACOPE is used to enable the comparator output to be placed onto
the external pin, ACMPO.
0 Analog comparator output not available on ACMPO
1 Analog comparator output is driven out on ACMPO
1:0
ACMOD
Analog Comparator Mode — ACMOD selects the type of compare event which sets ACF.
00 Encoding 0 — Comparator output falling edge
01 Encoding 1 — Comparator output rising edge
10 Encoding 2 — Comparator output falling edge
11 Encoding 3 — Comparator output rising or falling edge
9.4
Functional Description
The analog comparator can be used to compare two analog input voltages applied to ACMP+ and ACMP–;
or it can be used to compare an analog input voltage applied to ACMP– with an internal bandgap reference
voltage. ACBGS is used to select between the bandgap reference voltage or the ACMP+ pin as the input
to the non-inverting input of the analog comparator. The comparator output is high when the non-inverting
input is greater than the inverting input, and is low when the non-inverting input is less than the inverting
input. ACMOD is used to select the condition which will cause ACF to be set. ACF can be set on a rising
edge of the comparator output, a falling edge of the comparator output, or either a rising or a falling edge
(toggle). The comparator output can be read directly through ACO. The comparator output can be driven
onto the ACMPO pin using ACOPE.
MC9S08JM16 Series Data Sheet, Rev. 2
132
Freescale Semiconductor
Chapter 10
Analog-to-Digital Converter (S08ADC12V1)
10.1
Overview
The 12-bit analog-to-digital converter (ADC) is a successive approximation ADC designed for operation
within an integrated microcontroller system-on-chip.
NOTE
MC9S08JM16 series devices operate at a higher voltage range (2.7 V to
5.5 V) and do not include stop1 mode. Therefore, please disregard
references to stop1.
10.1.1
Module Configurations
This section provides information for configuring the ADC on this device.
10.1.1.1
Channel Assignments
The ADC channel assignments for the MC9S08JM16 Series devices are shown in the table below.
Reserved channels convert to an unknown value.
Table 10-1. ADC Channel Assignment
ADCH
Channel
Input
Pin Control
ADCH
Channel
Input
Pin Control
00000
AD0
PTB0/MISO2/ADP0
ADPC0
10000
AD16
VREFL
N/A
00001
AD1
PTB1/MOSI2/ADP1
ADPC1
10001
AD17
VREFL
N/A
00010
AD2
PTB2/SPSCK2/ADP2
ADPC2
10010
AD18
VREFL
N/A
00011
AD3
PTB3/SS2/ADP3
ADPC3
10011
AD19
VREFL
N/A
00100
AD4
PTB4/KBIP4/ADP4
ADPC4
10100
AD20
VREFL
N/A
00101
AD5
PTB5/KBIP5/ADP5
ADPC5
10101
AD21
VREFL
N/A
00110
AD6
VREFL
ADPC6
10110
AD22
Reserved
N/A
00111
AD7
VREFL
ADPC7
10111
AD23
Reserved
N/A
01000
AD8
PTD0/ADP8/ACMP+
ADPC8
11000
AD24
Reserved
N/A
01001
AD9
PTD1/ADP9/ACMP–
ADPC9
11001
AD25
Reserved
N/A
01010
AD10
VREFL
ADPC10
11010
AD26
Temperature
Sensor1
N/A
AD27
Internal Bandgap
N/A
Reserved
N/A
01011
AD11
VREFL
ADPC11
11011
01100
AD12
VREFL
ADPC12
11100
01101
AD13
VREFL
ADPC13
11101
VREFH
VREFH
N/A
01110
AD14
VREFL
ADPC14
11110
VREFL
VREFL
N/A
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
133
Chapter 10 Analog-to-Digital Converter (S08ADC12V1)
Table 10-1. ADC Channel Assignment (continued)
1
ADCH
Channel
Input
Pin Control
ADCH
Channel
Input
Pin Control
01111
AD15
VREFL
ADPC15
11111
module
disabled
None
N/A
For more information, see Section 10.1.1.5, “Temperature Sensor.”
NOTE
Selecting the internal bandgap channel requires BGBE =1 in SPMSC1, see
Section 5.7.7, “System Power Management Status and Control 1 Register
(SPMSC1).” For value of bandgap voltage reference see Appendix A.8,
“Analog Comparator (ACMP) Electricals.”
10.1.1.2
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
ALTCLK on this device is MCGERCLK.
The selected clock source 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.
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.
10.1.1.3
Hardware Trigger
The RTC on this device can be enabled as a hardware trigger for the ADC module by setting the
ADCSC2[ADTRG] bit. When enabled, the ADC will be triggered every time RTCINT matches
RTCMOD. The RTC interrupt does not have to be enabled to trigger the ADC.
The RTC can be configured to cause a hardware trigger in MCU run, wait, and stop3.
10.1.1.4
Analog Pin Enables
The ADC on MC9S08JM16 series contain only two analog pin enable registers, APCTL1 and APCTL2.
10.1.1.5
Temperature Sensor
The ADC module includes a temperature sensor whose output is connected to one of the ADC analog
channel inputs. Equation 10-1 provides an approximate transfer function of the temperature sensor.
Temp = 25 – ((VTEMP – VTEMP25) ÷ m)
Eqn. 10-1
where:
— VTEMP is the voltage of the temperature sensor channel at the ambient temperature.
MC9S08JM16 Series Data Sheet, Rev. 2
134
Freescale Semiconductor
Chapter 10 Analog-to-Digital Converter (S08ADC12V1)
— VTEMP25 is the voltage of the temperature sensor channel at 25°C.
— m is the hot or cold voltage versus temperature slope in V/°C.
For temperature calculations, use the VTEMP25 and m values from the Appendix A.9, “ADC
Characteristics.”
In application code, the user reads the temperature sensor channel, calculates VTEMP, and compares to
VTEMP25. If VTEMP is greater than VTEMP25, the cold slope value is applied in Equation 10-1. If VTEMP is
less than VTEMP25, the hot slope value is applied in Equation 10-1.
To improve accuracy, calibrate the bandgap voltage reference and temperature sensor. Calibrating at 25°C
will improve accuracy to ±4.5°C. Calibrating at 3 points, –40°C, 25°C, and 125°C will improve accuracy
to ±2.5°C. Once calibration has been completed, the user needs to calculate the slope for both hot and cold.
In application code, the user would then calculate the temperature using Equation 10-1 as detailed above
and then determine if the temperature is above or below 25°C. Once determined, the user can recalculate
the temperature using the hot or cold slope value obtained during calibration.
10.1.2
Low-Power Mode Operation
The ADC is capable of running in stop3 mode but requires LVDSE and LVDE in SPMSC1 to be set.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
135
Chapter 10 Analog-to-Digital Converter (S08ADC12V1)
IRQ/TPMCLK
USB SIE
CPU
HCS08 SYSTEM CONTROL
RESETS AND INTERRUPTS
MODES OF OPERATION
POWER MANAGEMENT
FULL SPEED
USB
USB ENDPOINT TRANSCEIVER
RAM
8-/16-BIT
SERIAL PERIPHERAL
INTERFACE MODULE (SPI2)
SERIAL COMMUNICATIONS
INTERFACE MODULE (SCI2)
COP
IRQ
LVD
IIC MODULE (IIC)
VDDAD
USER FLASH (IN BYTES)
MC9S08JM16 = 16,384
MC9S08JM8 = 8,192
SS2
SPSCK2
MOSI2
MISO2
RxD2
TxD2
SDA
SCL
6
ANALOG COMPARATOR
(ACMP)
ACMP+
8-/16-BIT
SERIAL PERIPHERAL
INTERFACE MODULE (SPI1)
SPSCK1
ACMPO
VSS
VUSB33
SYSTEM
VOLTAGE
REGULATOR
INTERFACE MODULE (SCI1)
2-CHANNEL TIMER/PWM
MODULE (TPM2)
REAL-TIME COUNTER
(RTC)
7-BIT KEYBOARD
INTERRUPT MODULE (KBI)
PTE5/MOSI1
MISO1
PTE4/MISO1
PORT E
TPMCLK
TPM1CH1
2
PTE3/TPM1CH1
PTE2/TPM1CH0
RxD1
TxD1
PTE1/RxD1
PTE0/TxD1
TPMCLK
TPM2CH1
TPM2CH0
PTF6
PTF5/TPM2CH1
PTF4/TPM2CH0
KBIPx
USB 3.3 V VOLTAGE REGULATOR
PTE6/SPSCK1
MOSI1
TPM1CH0
TPM1CHx
PTD2/KBIP2/ACMPO
PTE7/SS1
KBIPx
EXTAL
XTAL
PORT F
VDD
LOW-POWER OSCILLATOR
SERIAL COMMUNICATIONS
PTC5/RxD2
PTC4
PTC3/TxD2
PTC2
PTD1/ADP9/ACMP–
PTD0/ADP8/ACMP+
3
PTF1/TPM1CH3
PTF0/TPM1CH2
4
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 must not be driven above VDD.
4. Pin contains integrated pullup device.
5. When pin functions as KBI (KBIPEn = 1) and associated pin is configured to enable the
pullup device, KBEDGn can be used to reconfigure the pullup as a pulldown device.
PTG5/EXTAL
PORT G
VSSOSC
MODULE (TPM1)
PTB5/KBIP5/ADP5
PTB4/KBIP4/ADP4
PTB3/SS2/ADP3
PTB2/SPSCK2/ADP2
PTB1/MOSI2/ADP1
PTB0/MISO2/ADP0
PTD7
ACMP–
4-CHANNEL TIMER/PWM
MULTI-PURPOSE CLOCK
GENERATOR (MCG)
PTA5, PTA0
2
SS1
USER RAM (IN BYTES)
1024
2
PTC1/SDA
PTC0/SCL
PORT D
8-CHANNEL, 12-BIT
ANALOG-TO-DIGITAL
CONVERTER (ADC)
VSSAD
VREFL
VREFH
PORT B
BDC
PORT C
RESET
PORT A
HCS08 CORE
BKGD/MS
USBDP
USBDN
ON-CHIP ICE AND
DEBUG MODULE (DBG)
PTG4/XTAL
PTG3/KBIP7
PTG2/KBIP6
PTG1/KBIP1
PTG0/KBIP0
Figure 10-1. MC9S08JM16 Series Block Diagram Highlighting ADC Block and Pins
MC9S08JM16 Series Data Sheet, Rev. 2
136
Freescale Semiconductor
Analog-to-Digital Converter (S08ADC12V1)
10.1.3
Features
Features of the ADC module include:
• Linear successive approximation algorithm with 12-bit resolution
• Up to 28 analog inputs
• Output formatted in 12-, 10-, or 8-bit right-justified unsigned 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
• Temperature sensor
10.1.4
ADC Module Block Diagram
Figure 10-2 provides a block diagram of the ADC module.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
137
Analog-to-Digital Converter (S08ADC12V1)
ADIV
ADLPC
MODE
ADLSMP
ADTRG
2
ADCO
ADCH
1
ADCCFG
complete
COCO
ADCSC1
ADICLK
Compare true
AIEN
3
Async
Clock Gen
ADACK
MCU STOP
ADCK
÷2
ALTCLK
abort
transfer
convert
initialize
•••
AD0
sample
Control Sequencer
ADHWT
Bus Clock
Clock
Divide
AIEN 1
COCO 2
ADVIN
Interrupt
SAR Converter
AD27
VREFH
Data Registers
Sum
VREFL
Compare true
3
Compare Value Registers
ACFGT
Value
Compare
Logic
ADCSC2
Figure 10-2. ADC Block Diagram
10.2
External Signal Description
The ADC module supports up to 28 separate analog inputs. It also requires four supply/reference/ground
connections.
Table 10-2. Signal Properties
Name
Function
AD27 – AD0
Analog Channel inputs
VREFH
High reference voltage
VREFL
Low reference voltage
VDDAD
Analog power supply
VSSAD
Analog ground
MC9S08JM16 Series Data Sheet, Rev. 2
138
Freescale Semiconductor
Analog-to-Digital Converter (S08ADC12V1)
10.2.1
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.
10.2.2
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.
10.2.3
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 between the minimum VDDAD spec and the VDDAD potential (VREFH must never
exceed VDDAD).
10.2.4
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.
10.2.5
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.
10.3
Register Definition
These memory-mapped registers control and monitor operation of the ADC:
•
•
•
•
•
•
Status and control register, ADCSC1
Status and control register, ADCSC2
Data result registers, ADCRH and ADCRL
Compare value registers, ADCCVH and ADCCVL
Configuration register, ADCCFG
Pin control registers, APCTL1, APCTL2, APCTL3
10.3.1
Status and Control Register 1 (ADCSC1)
This section describes the function of the ADC status and control register (ADCSC1). Writing ADCSC1
aborts the current conversion and initiates a new conversion (if the ADCH bits are equal to a value other
than all 1s).
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
139
Analog-to-Digital Converter (S08ADC12V1)
7
R
6
5
AIEN
ADCO
0
0
4
3
2
1
0
1
1
COCO
ADCH
W
Reset:
0
1
1
1
Figure 10-3. Status and Control Register (ADCSC1)
Table 10-3. ADCSC1 Field Descriptions
Field
Description
7
COCO
Conversion Complete Flag. The COCO flag is a read-only bit 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 when ADCSC1 is written
or when ADCRL is read.
0 Conversion not completed
1 Conversion completed
6
AIEN
Interrupt Enable AIEN enables 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 enables continuous conversions.
0 One conversion following a write to the ADCSC1 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 ADCSC1 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 that selects one of the input channels. The input channels
are detailed in Table 10-4.
The successive approximation converter subsystem is turned off when the channel select bits are all set. This
feature allows for explicit disabling of the ADC and isolation of the input channel from all sources. Terminating
continuous conversions this way prevents an additional, single conversion from being performed. It is not
necessary to set the channel select bits to all ones 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.
Table 10-4. Input Channel Select
ADCH
Input Select
00000–01111
AD0–15
10000–11011
AD16–27
11100
Reserved
11101
VREFH
11110
VREFL
11111
Module disabled
MC9S08JM16 Series Data Sheet, Rev. 2
140
Freescale Semiconductor
Analog-to-Digital Converter (S08ADC12V1)
10.3.2
Status and Control Register 2 (ADCSC2)
The ADCSC2 register controls 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:
1
0
Bits 1 and 0 are reserved bits that must always be written to 0.
Figure 10-4. Status and Control Register 2 (ADCSC2)
Table 10-5. ADCSC2 Register Field Descriptions
Field
Description
7
ADACT
Conversion Active. 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. Selects the type of trigger used for initiating a conversion. Two types of triggers are
selectable: software trigger and hardware trigger. When software trigger is selected, a conversion is initiated
following a write to ADCSC1. When hardware trigger is selected, a conversion is initiated following the assertion
of the ADHWT input.
0 Software trigger selected
1 Hardware trigger selected
5
ACFE
4
ACFGT
10.3.3
Compare Function Enable. Enables the compare function.
0 Compare function disabled
1 Compare function enabled
Compare Function Greater Than Enable. Configures 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 value
1 Compare triggers when input is greater than or equal to compare value
Data Result High Register (ADCRH)
In 12-bit operation, ADCRH contains the upper four bits of the result of a 12-bit conversion. In 10-bit
mode, ADCRH contains the upper two bits of the result of a 10-bit conversion. When configured for 10-bit
mode, ADR[11:10] are cleared. When configured for 8-bit mode, ADR[11:8] are cleared.
In 12-bit and 10-bit mode, ADCRH is updated each time a conversion completes except when automatic
compare is enabled and the compare condition is not met. When a compare event does occur, the value is
the addition of the conversion result and the two’s complement of the compare value. In 12-bit and 10-bit
mode, reading ADCRH prevents the ADC from transferring subsequent conversion results into the result
registers until ADCRL is read. If ADCRL is not read until after the next conversion is completed, the
intermediate conversion result is lost. In 8-bit mode, there is no interlocking with ADCRL.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
141
Analog-to-Digital Converter (S08ADC12V1)
If the MODE bits are changed, any data in ADCRH becomes invalid.
R
7
6
5
4
3
2
1
0
0
0
0
0
ADR11
ADR10
ADR9
ADR8
0
0
0
0
0
0
0
0
W
Reset:
Figure 10-5. Data Result High Register (ADCRH)
10.3.4
Data Result Low Register (ADCRL)
ADCRL contains the lower eight bits of the result of a 12-bit or 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 12-bit and 10-bit mode, reading ADCRH
prevents the ADC from transferring subsequent conversion results into the result registers until ADCRL
is read. If ADCRL is not read until the after next conversion is completed, the intermediate conversion
results are lost. In 8-bit mode, there is no interlocking with ADCRH. If the MODE bits are changed, any
data in ADCRL becomes invalid.
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:
Figure 10-6. Data Result Low Register (ADCRL)
10.3.5
Compare Value High Register (ADCCVH)
In 12-bit mode, the ADCCVH register holds the upper four bits of the 12-bit compare value. When the
compare function is enabled, these bits are compared to the upper four bits of the result following a
conversion in 12-bit mode.
R
7
6
5
4
0
0
0
0
3
2
1
0
ADCV11
ADCV10
ADCV9
ADCV8
0
0
0
0
W
Reset:
0
0
0
0
Figure 10-7. Compare Value High Register (ADCCVH)
In 10-bit mode, the ADCCVH register holds the upper two bits of the 10-bit compare value (ADCV[9:8]).
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 mode, ADCCVH is not used during compare.
MC9S08JM16 Series Data Sheet, Rev. 2
142
Freescale Semiconductor
Analog-to-Digital Converter (S08ADC12V1)
10.3.6
Compare Value Low Register (ADCCVL)
This register holds the lower 8 bits of the 12-bit or 10-bit compare value or all 8 bits of the 8-bit compare
value. When the compare function is enabled, bits ADCV[7:0] are compared to the lower 8 bits of the
result following a conversion in 12-bit, 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 10-8. Compare Value Low Register (ADCCVL)
10.3.7
Configuration Register (ADCCFG)
ADCCFG selects the mode of operation, clock source, clock divide, and configures for low power and long
sample time.
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 10-9. Configuration Register (ADCCFG)
Table 10-6. ADCCFG Register Field Descriptions
Field
Description
7
ADLPC
Low-Power Configuration. ADLPC controls the speed and power configuration of the successive approximation
converter. This optimizes power consumption when higher sample rates are not required.
0 High speed configuration
1 Low power configuration:The power is reduced at the expense of maximum clock speed.
6:5
ADIV
Clock Divide Select. ADIV selects the divide ratio used by the ADC to generate the internal clock ADCK.
Table 10-7 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 12-, 10-, or 8-bit operation. See Table 10-8.
1:0
ADICLK
Input Clock Select. ADICLK bits select the input clock source to generate the internal clock ADCK. See
Table 10-9.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
143
Analog-to-Digital Converter (S08ADC12V1)
Table 10-7. 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 10-8. Conversion Modes
MODE
Mode Description
00
8-bit conversion (N=8)
01
12-bit conversion (N=12)
10
10-bit conversion (N=10)
11
Reserved
Table 10-9. Input Clock Select
ADICLK
10.3.8
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 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 10-10. Pin Control 1 Register (APCTL1)
Table 10-10. APCTL1 Register Field Descriptions
Field
Description
7
ADPC7
ADC Pin Control 7. ADPC7 controls 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 controls the pin associated with channel AD6.
0 AD6 pin I/O control enabled
1 AD6 pin I/O control disabled
MC9S08JM16 Series Data Sheet, Rev. 2
144
Freescale Semiconductor
Analog-to-Digital Converter (S08ADC12V1)
Table 10-10. APCTL1 Register Field Descriptions (continued)
Field
Description
5
ADPC5
ADC Pin Control 5. ADPC5 controls 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 controls 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 controls 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 controls the pin associated with channel AD2.
0 AD2 pin I/O control enabled
1 AD2 pin I/O control disabled
1
ADPC1
ADC Pin Control 1. ADPC1 controls 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 controls the pin associated with channel AD0.
0 AD0 pin I/O control enabled
1 AD0 pin I/O control disabled
10.3.9
Pin Control 2 Register (APCTL2)
APCTL2 controls 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 10-11. Pin Control 2 Register (APCTL2)
Table 10-11. APCTL2 Register Field Descriptions
Field
Description
7
ADPC15
ADC Pin Control 15. ADPC15 controls 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 controls 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 controls the pin associated with channel AD13.
0 AD13 pin I/O control enabled
1 AD13 pin I/O control disabled
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
145
Analog-to-Digital Converter (S08ADC12V1)
Table 10-11. APCTL2 Register Field Descriptions (continued)
Field
Description
4
ADPC12
ADC Pin Control 12. ADPC12 controls 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 controls 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 controls the pin associated with channel AD10.
0 AD10 pin I/O control enabled
1 AD10 pin I/O control disabled
1
ADPC9
ADC Pin Control 9. ADPC9 controls 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 controls the pin associated with channel AD8.
0 AD8 pin I/O control enabled
1 AD8 pin I/O control disabled
10.3.10 Pin Control 3 Register (APCTL3)
APCTL3 controls 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 10-12. Pin Control 3 Register (APCTL3)
Table 10-12. APCTL3 Register Field Descriptions
Field
Description
7
ADPC23
ADC Pin Control 23. ADPC23 controls 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 controls 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 controls 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 controls the pin associated with channel AD20.
0 AD20 pin I/O control enabled
1 AD20 pin I/O control disabled
MC9S08JM16 Series Data Sheet, Rev. 2
146
Freescale Semiconductor
Analog-to-Digital Converter (S08ADC12V1)
Table 10-12. APCTL3 Register Field Descriptions (continued)
Field
Description
3
ADPC19
ADC Pin Control 19. ADPC19 controls 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 controls the pin associated with channel AD18.
0 AD18 pin I/O control enabled
1 AD18 pin I/O control disabled
1
ADPC17
ADC Pin Control 17. ADPC17 controls 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 controls the pin associated with channel AD16.
0 AD16 pin I/O control enabled
1 AD16 pin I/O control disabled
10.4
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. In 12-bit
and 10-bit mode, the selected channel voltage is converted by a successive approximation algorithm into
a 12-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 (ADCRH and ADCRL). In
10-bit mode, the result is rounded to 10 bits and placed in the data registers (ADCRH and ADCRL). In
8-bit mode, the result is rounded to 8 bits and placed in ADCRL. 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
with any of the conversion modes and configurations.
10.4.1
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 two. 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).
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
147
Analog-to-Digital Converter (S08ADC12V1)
•
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 do not perform according to specifications. If the available clocks
are too fast, 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.
10.4.2
Input Select and Pin Control
The pin control registers (APCTL3, APCTL2, and APCTL1) 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.
10.4.3
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.
10.4.4
Conversion Control
Conversions can be performed in 12-bit mode, 10-bit mode, or 8-bit mode as determined by the MODE
bits. Conversions can be initiated by 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.
10.4.4.1
Initiating Conversions
A conversion is initiated:
• Following a write to ADCSC1 (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.
MC9S08JM16 Series Data Sheet, Rev. 2
148
Freescale Semiconductor
Analog-to-Digital Converter (S08ADC12V1)
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 ADCSC1 is
written and continue until aborted. In hardware triggered operation, continuous conversions begin after a
hardware trigger event and continue until aborted.
10.4.4.2
Completing Conversions
A conversion is completed when the result of the conversion is transferred into the data result registers,
ADCRH and ADCRL. 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 ADCRH and ADCRL if
the previous data is in the process of being read while in 12-bit or 10-bit MODE (the ADCRH register has
been read but the ADCRL 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.
10.4.4.3
Aborting Conversions
Any conversion in progress is aborted when:
•
A write to ADCSC1 occurs (the current conversion will be aborted and a new conversion will be
initiated, if ADCH are not all 1s).
•
A write to ADCSC2, ADCCFG, ADCCVH, or ADCCVL 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, ADCRH and ADCRL, are not altered.
However, they continue to be the values transferred after the completion of the last successful conversion.
If the conversion was aborted by a reset, ADCRH and ADCRL return to their reset states.
10.4.4.4
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).
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
149
Analog-to-Digital Converter (S08ADC12V1)
10.4.4.5
Sample Time and 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, 10-bit or 12-bit), and the frequency of the conversion clock (fADCK).
After the module becomes active, sampling of the input begins. ADLSMP selects between short (3.5
ADCK cycles) and long (23.5 ADCK cycles) 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 result of the conversion is transferred to ADCRH and ADCRL 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 10-13.
Table 10-13. 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 or 12-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 or 12-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 or 12-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 or 12-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 or 12-bit;
fBUS > fADCK
xx
0
20 ADCK cycles
Subsequent continuous 8-bit;
fBUS > fADCK/11
xx
1
37 ADCK cycles
Subsequent continuous 10-bit or 12-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
MC9S08JM16 Series Data Sheet, Rev. 2
150
Freescale Semiconductor
Analog-to-Digital Converter (S08ADC12V1)
NOTE
The ADCK frequency must be between fADCK minimum and fADCK
maximum to meet ADC specifications.
10.4.5
Automatic Compare Function
The compare function can be configured to check for an upper or lower limit. After the input is sampled
and converted, the result is added to the two’s complement of the compare value (ADCCVH and
ADCCVL). 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 ADCRH and ADCRL.
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 monitor the voltage on a channel while the MCU
is in wait or stop3 mode. The ADC interrupt wakes the MCU when the
compare condition is met.
10.4.6
MCU Wait Mode Operation
Wait mode is a lower power-consumption standby mode from which recovery is 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).
10.4.7
MCU Stop3 Mode Operation
Stop mode is a low power-consumption standby mode during which most or all clock sources on the MCU
are disabled.
10.4.7.1
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 ADCRH and ADCRL
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
151
Analog-to-Digital Converter (S08ADC12V1)
are unaffected by stop3 mode. After exiting from stop3 mode, a software or hardware trigger is required
to resume conversions.
10.4.7.2
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
The ADC module can 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 must ensure the data
transfer blocking mechanism (discussed in Section 10.4.4.2, “Completing
Conversions,”) is cleared when entering stop3 and continuing ADC
conversions.
10.4.8
MCU Stop2 Mode Operation
The ADC module is automatically disabled when the MCU enters stop2 mode. All module registers
contain their reset values following exit from stop2. Therefore, the module must be re-enabled and
re-configured following exit from stop2.
10.5
Initialization Information
This section gives an example that provides some basic direction on how to initialize and configure the
ADC module. You can configure the module for 8-, 10-, or 12-bit resolution, single or continuous
conversion, and a polled or interrupt approach, among many other options. Refer to Table 10-7,
Table 10-8, and Table 10-9 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.
MC9S08JM16 Series Data Sheet, Rev. 2
152
Freescale Semiconductor
Analog-to-Digital Converter (S08ADC12V1)
10.5.1
ADC Module Initialization Example
10.5.1.1
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.
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.
10.5.1.2
Pseudo-Code Example
In this example, the ADC module is 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 is derived from
the bus clock divided by 1.
ADCCFG = 0x98 (%10011000)
Bit
Bit
Bit
Bit
Bit
7
6:5
4
3:2
1:0
ADLPC
ADIV
ADLSMP
MODE
ADICLK
1
00
1
10
00
Configures for low power (lowers maximum clock speed)
Sets the ADCK to the input clock ÷ 1
Configures for long sample time
Sets mode at 10-bit conversions
Selects bus clock as input clock source
ADCSC2 = 0x00 (%00000000)
Bit
Bit
Bit
Bit
Bit
Bit
7
6
5
4
3:2
1:0
ADACT
ADTRG
ACFE
ACFGT
0
0
0
0
00
00
Flag indicates if a conversion is in progress
Software trigger selected
Compare function disabled
Not used in this example
Reserved, always reads zero
Reserved for Freescale’s internal use; always write zero
ADCSC1 = 0x41 (%01000001)
Bit
Bit
Bit
Bit
7
6
5
4:0
COCO
AIEN
ADCO
ADCH
0
1
0
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
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
153
Analog-to-Digital Converter (S08ADC12V1)
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
Reset
Initialize ADC
ADCCFG = 0x98
ADCSC2 = 0x00
ADCSC1 = 0x41
Check
COCO=1?
No
Yes
Read ADCRH
Then ADCRL To
Clear COCO Bit
Continue
Figure 10-13. Initialization Flowchart for Example
10.6
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.
10.6.1
External Pins and Routing
The following sections discuss the external pins associated with the ADC module and how they must be
used for best results.
10.6.1.1
Analog Supply Pins
The ADC module has analog power and ground supplies (VDDAD and VSSAD) available as separate pins
on some devices. VSSAD is shared on the same pin as the MCU digital VSS on some devices. On other
MC9S08JM16 Series Data Sheet, Rev. 2
154
Freescale Semiconductor
Analog-to-Digital Converter (S08ADC12V1)
devices, VSSAD and VDDAD are shared with the MCU digital supply pins. In these cases, there are separate
pads for the analog supplies 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.
If separate power supplies are used for analog and digital power, the ground connection between these
supplies must be at the VSSAD pin. This must be the only ground connection between these supplies if
possible. The VSSAD pin makes a good single point ground location.
10.6.1.2
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 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. 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 causes a voltage drop that could result in conversion errors.
Inductance in this path must be minimum (parasitic only).
10.6.1.3
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 is in its high impedance state and the pullup is disabled. Also, the input buffer
draws DC current when its input is not at VDD or VSS. Setting the pin control register bits for all pins used
as analog inputs must 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 0xFFF (full scale 12-bit representation), 0x3FF
(full scale 10-bit representation) or 0xFF (full scale 8-bit representation). If the input is equal to or less
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
155
Analog-to-Digital Converter (S08ADC12V1)
than VREFL, the converter circuit converts it to 0x000. Input voltages between VREFH and VREFL are
straight-line linear conversions. There is 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 must not be
transitioning during conversions.
10.6.2
Sources of Error
Several sources of error exist for A/D conversions. These are discussed in the following sections.
10.6.2.1
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 12-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 2 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.
10.6.2.2
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, 10 in 10-bit or 12 in 12-bit mode).
10.6.2.3
Noise-Induced Errors
System noise that 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 ADCSC1 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.
MC9S08JM16 Series Data Sheet, Rev. 2
156
Freescale Semiconductor
Analog-to-Digital Converter (S08ADC12V1)
•
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 improves
noise issues, but affects the sample rate based on the external analog source resistance).
• 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.
10.6.2.4
Code Width and Quantization Error
The ADC quantizes the ideal straight-line transfer function into 4096 steps (in 12-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, 10 or
12), defined as 1LSB, is:
1 lsb = (VREFH – VREFL) / 2N
Eqn. 10-2
There is an inherent quantization error due to the digitization of the result. For 8-bit or 10-bit conversions
the code transitions 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
±1/2 lsb in 8- or 10-bit mode. As a consequence, however, the code width of the first (0x000) conversion
is only 1/2 lsb and the code width of the last (0xFF or 0x3FF) is 1.5 lsb.
For 12-bit conversions the code transitions only after the full code width is present, so the quantization
error is −1 lsb to 0 lsb and the code width of each step is 1 lsb.
10.6.2.5
Linearity Errors
The ADC may also exhibit non-linearity of several forms. Every effort has been made to reduce these
errors but the system must 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 (1/2 lsb in 8-bit or 10-bit
modes and 1 lsb in 12-bit mode). If the first conversion is 0x001, the difference between the actual
0x001 code width and its ideal (1 lsb) 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 (1.5 lsb in 8-bit or 10-bit modes and 1LSB in 12-bit
mode). If the last conversion is 0x3FE, the difference between the actual 0x3FE 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.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
157
Analog-to-Digital Converter (S08ADC12V1)
•
•
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 includes all forms of error.
10.6.2.6
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
converter yields the lower code (and vice-versa). However, even 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 ±1/2 lsb in 8-bit or 10-bit mode, or around 2 lsb in 12-bit mode,
and increases with noise.
This error may be reduced by repeatedly sampling the input and averaging the result. Additionally the
techniques discussed in Section 10.6.2.3 reduces 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 never converted for any input value.
In 8-bit or 10-bit mode, the ADC is guaranteed to be monotonic and have no missing codes.
MC9S08JM16 Series Data Sheet, Rev. 2
158
Freescale Semiconductor
Chapter 11
Inter-Integrated Circuit (S08IICV2)
11.1
Introduction
The MC9S08JM16 series of microcontrollers have 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 PTC0 and PTC1, respectively.
NOTE
MC9S08JM16 devices operate at a higher voltage range (2.7 V to 5.5 V)
and do not include stop1 mode. Therefore, please disregard references to
stop1.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
159
Chapter 11 Inter-Integrated Circuit (S08IICV2)
IRQ/TPMCLK
USB SIE
CPU
HCS08 SYSTEM CONTROL
RESETS AND INTERRUPTS
MODES OF OPERATION
POWER MANAGEMENT
FULL SPEED
USB
USB ENDPOINT TRANSCEIVER
RAM
8-/16-BIT
SERIAL PERIPHERAL
INTERFACE MODULE (SPI2)
SERIAL COMMUNICATIONS
INTERFACE MODULE (SCI2)
COP
IRQ
LVD
IIC MODULE (IIC)
VDDAD
USER FLASH (IN BYTES)
MC9S08JM16 = 16,384
MC9S08JM8 = 8,192
SS2
SPSCK2
MOSI2
MISO2
RxD2
TxD2
SDA
SCL
6
ANALOG COMPARATOR
(ACMP)
ACMP+
8-/16-BIT
SERIAL PERIPHERAL
INTERFACE MODULE (SPI1)
SPSCK1
ACMPO
VSS
VUSB33
SYSTEM
VOLTAGE
REGULATOR
INTERFACE MODULE (SCI1)
2-CHANNEL TIMER/PWM
MODULE (TPM2)
REAL-TIME COUNTER
(RTC)
7-BIT KEYBOARD
INTERRUPT MODULE (KBI)
PTE5/MOSI1
MISO1
PTE4/MISO1
PORT E
TPMCLK
TPM1CH1
2
PTE3/TPM1CH1
PTE2/TPM1CH0
RxD1
TxD1
PTE1/RxD1
PTE0/TxD1
TPMCLK
TPM2CH1
TPM2CH0
PTF6
PTF5/TPM2CH1
PTF4/TPM2CH0
KBIPx
USB 3.3 V VOLTAGE REGULATOR
PTE6/SPSCK1
MOSI1
TPM1CH0
TPM1CHx
PTD2/KBIP2/ACMPO
PTE7/SS1
KBIPx
EXTAL
XTAL
PORT F
VDD
LOW-POWER OSCILLATOR
SERIAL COMMUNICATIONS
PTC5/RxD2
PTC4
PTC3/TxD2
PTC2
PTD1/ADP9/ACMP–
PTD0/ADP8/ACMP+
3
PTF1/TPM1CH3
PTF0/TPM1CH2
4
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 must not be driven above VDD.
4. Pin contains integrated pullup device.
5. When pin functions as KBI (KBIPEn = 1) and associated pin is configured to enable the
pullup device, KBEDGn can be used to reconfigure the pullup as a pulldown device.
PTG5/EXTAL
PORT G
VSSOSC
MODULE (TPM1)
PTB5/KBIP5/ADP5
PTB4/KBIP4/ADP4
PTB3/SS2/ADP3
PTB2/SPSCK2/ADP2
PTB1/MOSI2/ADP1
PTB0/MISO2/ADP0
PTD7
ACMP–
4-CHANNEL TIMER/PWM
MULTI-PURPOSE CLOCK
GENERATOR (MCG)
PTA5, PTA0
2
SS1
USER RAM (IN BYTES)
1024
2
PTC1/SDA
PTC0/SCL
PORT D
8-CHANNEL, 12-BIT
ANALOG-TO-DIGITAL
CONVERTER (ADC)
VSSAD
VREFL
VREFH
PORT B
BDC
PORT C
RESET
PORT A
HCS08 CORE
BKGD/MS
USBDP
USBDN
ON-CHIP ICE AND
DEBUG MODULE (DBG)
PTG4/XTAL
PTG3/KBIP7
PTG2/KBIP6
PTG1/KBIP1
PTG0/KBIP0
Figure 11-1. MC9S08JM16 Series Block Diagram Highlighting the IIC Block and Pins
MC9S08JM16 Series Data Sheet, Rev. 2
160
Freescale Semiconductor
Inter-Integrated Circuit (S08IICV2)
11.1.1
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
• General call recognition
• 10-bit address extension
11.1.2
Modes of Operation
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 continues 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. Stop2 resets the register contents.
11.1.3
Block Diagram
Figure 11-2 is a block diagram of the IIC.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
161
Inter-Integrated Circuit (S08IICV2)
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 11-2. IIC Functional Block Diagram
11.2
External Signal Description
This section describes each user-accessible pin signal.
11.2.1
SCL — Serial Clock Line
The bidirectional SCL is the serial clock line of the IIC system.
11.2.2
SDA — Serial Data Line
The bidirectional SDA is the serial data line of the IIC system.
11.3
Register Definition
This section consists of the IIC register descriptions in address order.
Refer to the direct-page register summary in the memory chapter of this document for the absolute address
assignments for all IIC registers. This section refers to registers and control bits only by their names. A
MC9S08JM16 Series Data Sheet, Rev. 2
162
Freescale Semiconductor
Inter-Integrated Circuit (S08IICV2)
Freescale-provided equate or header file is used to translate these names into the appropriate absolute
addresses.
11.3.1
IIC Address Register (IICA)
7
6
5
4
3
2
1
AD7
AD6
AD5
AD4
AD3
AD2
AD1
0
0
0
0
0
0
0
R
0
0
W
Reset
0
= Unimplemented or Reserved
Figure 11-3. IIC Address Register (IICA)
Table 11-1. IICA Field Descriptions
Field
Description
7–1
AD[7:1]
Slave Address. The AD[7:1] field contains the slave address to be used by the IIC module. This field is used on
the 7-bit address scheme and the lower seven bits of the 10-bit address scheme.
11.3.2
IIC Frequency Divider Register (IICF)
7
6
5
4
3
2
1
0
0
0
0
R
MULT
ICR
W
Reset
0
0
0
0
0
Figure 11-4. IIC Frequency Divider Register (IICF)
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
163
Inter-Integrated Circuit (S08IICV2)
Table 11-2. IICF Field Descriptions
Field
7–6
MULT
5–0
ICR
Description
IIC Multiplier Factor. The MULT bits define the multiplier factor, mul. This factor, along with the SCL divider,
generates 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
IIC Clock Rate. The ICR bits are used to prescale the bus clock for bit rate selection. These bits and the MULT
bits determine the IIC baud rate, the SDA hold time, the SCL Start hold time, and the SCL Stop hold time.
Table 11-4 provides the SCL divider and hold values for corresponding values of the ICR.
The SCL divider multiplied by multiplier factor mul generates IIC baud rate.
bus speed (Hz)
IIC baud rate = --------------------------------------------mul × SCLdivider
Eqn. 11-1
SDA hold time is the delay from the falling edge of SCL (IIC clock) to the changing of SDA (IIC data).
SDA hold time = bus period (s) × mul × SDA hold value
Eqn. 11-2
SCL start hold time is the delay from the falling edge of SDA (IIC data) while SCL is high (Start condition) to the
falling edge of SCL (IIC clock).
SCL Start hold time = bus period (s) × mul × SCL Start hold value
Eqn. 11-3
SCL stop hold time is the delay from the rising edge of SCL (IIC clock) to the rising edge of SDA
SDA (IIC data) while SCL is high (Stop condition).
SCL Stop hold time = bus period (s) × mul × SCL Stop hold value
Eqn. 11-4
For example, if the bus speed is 8 MHz, the table below shows the possible hold time values with different
ICR and MULT selections to achieve an IIC baud rate of 100kbps.
Table 11-3. Hold Time Values for 8 MHz Bus Speed
Hold Times (μs)
MULT
ICR
SDA
SCL Start
SCL Stop
0x2
0x00
3.500
3.000
5.500
0x1
0x07
2.500
4.000
5.250
0x1
0x0B
2.250
4.000
5.250
0x0
0x14
2.125
4.250
5.125
0x0
0x18
1.125
4.750
5.125
MC9S08JM16 Series Data Sheet, Rev. 2
164
Freescale Semiconductor
Inter-Integrated Circuit (S08IICV2)
Table 11-4. IIC Divider and Hold Values
ICR
(hex)
SCL
Divider
SDA Hold
Value
SCL Hold
(Start)
Value
SDA Hold
(Stop)
Value
ICR
(hex)
SCL
Divider
SDA Hold
Value
SCL Hold
(Start)
Value
SCL Hold
(Stop)
Value
00
20
7
6
11
20
160
17
78
81
01
22
7
7
12
21
192
17
94
97
02
24
8
8
13
22
224
33
110
113
03
26
8
9
14
23
256
33
126
129
04
28
9
10
15
24
288
49
142
145
05
30
9
11
16
25
320
49
158
161
06
34
10
13
18
26
384
65
190
193
07
40
10
16
21
27
480
65
238
241
08
28
7
10
15
28
320
33
158
161
09
32
7
12
17
29
384
33
190
193
0A
36
9
14
19
2A
448
65
222
225
0B
40
9
16
21
2B
512
65
254
257
0C
44
11
18
23
2C
576
97
286
289
0D
48
11
20
25
2D
640
97
318
321
0E
56
13
24
29
2E
768
129
382
385
0F
68
13
30
35
2F
960
129
478
481
10
48
9
18
25
30
640
65
318
321
11
56
9
22
29
31
768
65
382
385
12
64
13
26
33
32
896
129
446
449
13
72
13
30
37
33
1024
129
510
513
14
80
17
34
41
34
1152
193
574
577
15
88
17
38
45
35
1280
193
638
641
16
104
21
46
53
36
1536
257
766
769
17
128
21
58
65
37
1920
257
958
961
18
80
9
38
41
38
1280
129
638
641
19
96
9
46
49
39
1536
129
766
769
1A
112
17
54
57
3A
1792
257
894
897
1B
128
17
62
65
3B
2048
257
1022
1025
1C
144
25
70
73
3C
2304
385
1150
1153
1D
160
25
78
81
3D
2560
385
1278
1281
1E
192
33
94
97
3E
3072
513
1534
1537
1F
240
33
118
121
3F
3840
513
1918
1921
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
165
Inter-Integrated Circuit (S08IICV2)
11.3.3
IIC Control Register (IICC1)
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 11-5. IIC Control Register (IICC1)
Table 11-5. IICC1 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 changes 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
must be set according to the type of transfer required. Therefore, for address cycles, this bit is always high. When
addressed as a slave, this bit must 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 master and slave receivers.
0 An acknowledge signal is sent out to the bus after receiving one data byte
1 No acknowledge signal response is sent
2
RSTA
Repeat start. Writing a 1 to this bit generates a repeated start condition provided it is the current master. This
bit is always read as cleared. Attempting a repeat at the wrong time results in loss of arbitration.
11.3.4
IIC Status Register (IICS)
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 11-6. IIC Status Register (IICS)
MC9S08JM16 Series Data Sheet, Rev. 2
166
Freescale Semiconductor
Inter-Integrated Circuit (S08IICV2)
Table 11-6. IICS Field Descriptions
Field
Description
7
TCF
Transfer Complete Flag. This bit is set on the completion of a byte transfer. 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
IICD register in receive mode or writing to the IICD 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 or
when the GCAEN bit is set and a general call is received. Writing the IICC 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 1 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 1 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
11.3.5
IIC Data I/O Register (IICD)
7
6
5
4
3
2
1
0
0
0
0
0
R
DATA
W
Reset
0
0
0
0
Figure 11-7. IIC Data I/O Register (IICD)
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
167
Inter-Integrated Circuit (S08IICV2)
Table 11-7. IICD Field Descriptions
Field
Description
7–0
DATA
Data — In master transmit mode, when data is written to the IICD, 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 must be
switched before reading the IICD 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.
The TX bit in IICC 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, reading the IICD does not initiate the receive.
Reading the IICD returns the last byte received while the IIC is configured in master receive or slave
receive modes. The IICD does not reflect every byte transmitted on the IIC bus, nor can software verify
that a byte has been written to the IICD correctly by reading it back.
In master transmit mode, the first byte of data written to IICD following assertion of MST is used for the
address transfer and must comprise of the calling address (in bit 7 to bit 1) concatenated with the required
R/W bit (in position bit 0).
11.3.6
IIC Control Register 2 (IICC2)
7
6
GCAEN
ADEXT
0
0
R
5
4
3
0
0
0
2
1
0
AD10
AD9
AD8
0
0
0
W
Reset
0
0
0
= Unimplemented or Reserved
Figure 11-8. IIC Control Register (IICC2)
Table 11-8. IICC2 Field Descriptions
Field
Description
7
GCAEN
General Call Address Enable. The GCAEN bit enables or disables general call address.
0 General call address is disabled
1 General call address is enabled
6
ADEXT
Address Extension. The ADEXT bit controls the number of bits used for the slave address.
0 7-bit address scheme
1 10-bit address scheme
2–0
AD[10:8]
Slave Address. The AD[10:8] field contains the upper three bits of the slave address in the 10-bit address
scheme. This field is only valid when the ADEXT bit is set.
MC9S08JM16 Series Data Sheet, Rev. 2
168
Freescale Semiconductor
Inter-Integrated Circuit (S08IICV2)
11.4
Functional Description
This section provides a complete functional description of the IIC module.
11.4.1
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 pullup 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 must not be confused with the CPU stop instruction. The IIC bus system communication
is described briefly in the following sections and illustrated in Figure 11-9.
msb
SCL
1
SDA
lsb
2
3
4
5
6
7
8
msb
9
AD7 AD6 AD5 AD4 AD3 AD2 AD1 R/W
Start
Signal
1
SDA
3
4
5
Calling Address
4
5
6
7
8
D7
D6
D5
D4
D3
D2
D1
D0
6
7
8
9
Read/ Ack
Write Bit
1
XX
Repeated
Start
Signal
9
No
Ack
Bit
msb
AD7 AD6 AD5 AD4 AD3 AD2 AD1 R/W
Start
Signal
3
Data Byte
lsb
2
2
Read/ Ack
Write Bit
Calling Address
msb
SCL
XXX
lsb
1
Stop
Signal
lsb
2
3
4
5
6
7
8
9
AD7 AD6 AD5 AD4 AD3 AD2 AD1 R/W
New Calling Address
Read/
Write
No
Ack
Bit
Stop
Signal
Figure 11-9. IIC Bus Transmission Signals
11.4.1.1
Start Signal
When the bus is free, no master device is engaging the bus (SCL and SDA lines are at logical high), a
master may initiate communication by sending a start signal. As shown in Figure 11-9, 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.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
169
Inter-Integrated Circuit (S08IICV2)
11.4.1.2
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 responds by sending
back an acknowledge bit. This is done by pulling the SDA low at the ninth clock (see Figure 11-9).
No two slaves in the system may have the same address. If the IIC module is the master, it must not
transmit an address 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 reverts to slave mode and operates correctly
even if it is being addressed by another master.
11.4.1.3
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 11-9. 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 ninth 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.
11.4.1.4
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 11-9).
The master can generate a stop even if the slave has generated an acknowledge at which point the slave
must release the bus.
MC9S08JM16 Series Data Sheet, Rev. 2
170
Freescale Semiconductor
Inter-Integrated Circuit (S08IICV2)
11.4.1.5
Repeated Start Signal
As shown in Figure 11-9, 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.
11.4.1.6
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.
11.4.1.7
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 11-10). 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.
Delay
Start Counting High Period
SCL1
SCL2
SCL
Internal Counter Reset
Figure 11-10. IIC Clock Synchronization
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
171
Inter-Integrated Circuit (S08IICV2)
11.4.1.8
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 a case, it halts the bus clock and forces
the master clock into wait states until the slave releases the SCL line.
11.4.1.9
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.
11.4.2
10-bit Address
For 10-bit addressing, 0x11110 is used for the first 5 bits of the first address byte. Various combinations of
read/write formats are possible within a transfer that includes 10-bit addressing.
11.4.2.1
Master-Transmitter Addresses a Slave-Receiver
The transfer direction is not changed (see Table 11-9). When a 10-bit address follows a start condition,
each slave compares the first seven bits of the first byte of the slave address (11110XX) with its own
address and tests whether the eighth bit (R/W direction bit) is 0. More than one device can find a match
and generate an acknowledge (A1). Then, each slave that finds a match compares the eight bits of the
second byte of the slave address with its own address. Only one slave finds a match and generates an
acknowledge (A2). The matching slave remains addressed by the master until it receives a stop condition
(P) or a repeated start condition (Sr) followed by a different slave address.
Slave Address 1st 7 bits
R/W
S
Slave Address 2nd byte
A1
11110 + AD10 + AD9
0
A2
Data
A
...
Data
A/A
P
AD[8:1]
Table 11-9. Master-Transmitter Addresses Slave-Receiver with a 10-bit Address
After the master-transmitter has sent the first byte of the 10-bit address, the slave-receiver sees an IIC
interrupt. Software must ensure the contents of IICD are ignored and not treated as valid data for this
interrupt.
11.4.2.2
Master-Receiver Addresses a Slave-Transmitter
The transfer direction is changed after the second R/W bit (see Table 11-10). Up to and including
acknowledge bit A2, the procedure is the same as that described for a master-transmitter addressing a
slave-receiver. After the repeated start condition (Sr), a matching slave remembers that it was addressed
before. This slave then checks whether the first seven bits of the first byte of the slave address following
Sr are the same as they were after the start condition (S) and tests whether the eighth (R/W) bit is 1. If there
is a match, the slave considers that it has been addressed as a transmitter and generates acknowledge A3.
The slave-transmitter remains addressed until it receives a stop condition (P) or a repeated start condition
(Sr) followed by a different slave address.
MC9S08JM16 Series Data Sheet, Rev. 2
172
Freescale Semiconductor
Inter-Integrated Circuit (S08IICV2)
After a repeated start condition (Sr), all other slave devices also compare the first seven bits of the first
byte of the slave address with their own addresses and test the eighth (R/W) bit. However, none of them
are addressed because R/W = 1 (for 10-bit devices) or the 11110XX slave address (for 7-bit devices) does
not match.
S
Slave Address
1st 7 bits
R/W
11110 + AD10 + AD9
0
A1
Slave Address
2nd byte
A2
AD[8:1]
Sr
Slave Address
1st 7 bits
R/W
11110 + AD10 + AD9
1
A3
Data
A
...
Data
A
P
Table 11-10. Master-Receiver Addresses a Slave-Transmitter with a 10-bit Address
After the master-receiver has sent the first byte of the 10-bit address, the slave-transmitter sees an IIC
interrupt. Software must ensure the contents of IICD are ignored and not treated as valid data for this
interrupt.
11.4.3
General Call Address
General calls can be requested in 7-bit address or 10-bit address. If the GCAEN bit is set, the IIC matches
the general call address as well as its own slave address. When the IIC responds to a general call, it acts as
a slave-receiver and the IAAS bit is set after the address cycle. Software must read the IICD register after
the first byte transfer to determine whether the address matches is its own slave address or a general call.
If the value is 00, the match is a general call. If the GCAEN bit is clear, the IIC ignores any data supplied
from a general call address by not issuing an acknowledgement.
11.5
Resets
The IIC is disabled after reset. The IIC cannot cause an MCU reset.
11.6
Interrupts
The IIC generates a single interrupt.
An interrupt from the IIC is generated when any of the events in Table 11-11 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 1 to it in the interrupt routine. You
can determine the interrupt type by reading the status register.
Table 11-11. Interrupt Summary
11.6.1
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
Byte Transfer Interrupt
The TCF (transfer complete flag) bit is set at the falling edge of the ninth clock to indicate the completion
of byte transfer.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
173
Inter-Integrated Circuit (S08IICV2)
11.6.2
Address Detect Interrupt
When the calling address matches the programmed slave address (IIC address register) or when the
GCAEN bit is set and a general call is received, 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.
11.6.3
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 writing a 1 to it.
MC9S08JM16 Series Data Sheet, Rev. 2
174
Freescale Semiconductor
Inter-Integrated Circuit (S08IICV2)
11.7
Initialization/Application Information
Module Initialization (Slave)
1. Write: IICC2
— to enable or disable general call
— to select 10-bit or 7-bit addressing mode
2. Write: IICA
— to set the slave address
3. Write: IICC1
— to enable IIC and interrupts
4. Initialize RAM variables (IICEN = 1 and IICIE = 1) for transmit data
5. Initialize RAM variables used to achieve the routine shown in Figure 11-12
Module Initialization (Master)
1. Write: IICF
— to set the IIC baud rate (example provided in this chapter)
2. Write: IICC1
— to enable IIC and interrupts
3. Initialize RAM variables (IICEN = 1 and IICIE = 1) for transmit data
4. Initialize RAM variables used to achieve the routine shown in Figure 11-12
5. Write: IICC1
— to enable TX
Register Model
AD[7:1]
IICA
0
When addressed as a slave (in slave mode), the module responds to this address
MULT
IICF
ICR
Baud rate = BUSCLK / (2 x MULT x (SCL DIVIDER))
IICC1
IICEN
IICIE
MST
TX
TXAK
RSTA
0
0
BUSY
ARBL
0
SRW
IICIF
RXAK
AD9
AD8
Module configuration
IICS
TCF
IAAS
Module status flags
DATA
IICD
Data register; Write to transmit IIC data read to read IIC data
IICC2 GCAEN ADEXT
0
0
0
AD10
Address configuration
Figure 11-11. IIC Module Quick Start
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
175
Inter-Integrated Circuit (S08IICV2)
Clear
IICIF
Master
Mode
?
Y
TX
N
Arbitration
Lost
?
Y
RX
Tx/Rx
?
N
Last Byte
Transmitted
?
N
Clear ARBL
Y
RXAK=0
?
Last
Byte to Be Read
?
N
N
N
Y
Y
IAAS=1
?
Y
IAAS=1
?
Y
Address Transfer
See Note 1
Y
End of
Addr Cycle
(Master Rx)
?
Y
Y
(Read)
2nd Last
Byte to Be Read
?
N
SRW=1
?
Write Next
Byte to IICD
Set TXACK =1
Generate
Stop Signal
(MST = 0)
TX
Y
Set TX
Mode
RX
TX/RX
?
N (Write)
N
N
Data Transfer
See Note 2
ACK from
Receiver
?
N
Switch to
Rx Mode
Dummy Read
from IICD
Generate
Stop Signal
(MST = 0)
Read Data
from IICD
and Store
Read Data
from IICD
and Store
Tx Next
Byte
Write Data
to IICD
Set RX
Mode
Switch to
Rx Mode
Dummy Read
from IICD
Dummy Read
from IICD
RTI
1
If general call is enabled, a check must be done to determine whether the received address was a general call address (0x00).
If the received address was a general call address, then the general call must be handled by user software.
2 When 10-bit addressing is used to address a slave, the slave sees an interrupt following the first byte of the extended address.
User software must ensure that for this interrupt, the contents of IICD are ignored and not treated as a valid data transfer
Figure 11-12. Typical IIC Interrupt Routine
MC9S08JM16 Series Data Sheet, Rev. 2
176
Freescale Semiconductor
Chapter 12
Multi-Purpose Clock Generator (S08MCGV1)
12.1
Introduction
The multi-purpose clock generator (MCG) module provides several clock source choices for the MCU,
which contains a frequency-locked loop (FLL) and a phase-locked loop (PLL) The module can select
either of the FLL or PLL clocks, or either of the internal or external reference clocks as a source for the
MCU system clock. Whichever clock source is chosen, it is passed through a reduced bus divider which
allows a lower output clock frequency to be derived. The MCG also controls an external oscillator (XOSC)
for the use of a crystal or resonator as the external reference clock.
For USB operation on the MC9S08JM60 series, the MCG must be configured for PLL engaged external
(PEE) mode using a crystal in order to achieve an MCGOUT frequency of 48 MHz.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
177
Chapter 12 Multi-Purpose Clock Generator (S08MCGV1)
IRQ/TPMCLK
USB SIE
CPU
HCS08 SYSTEM CONTROL
RESETS AND INTERRUPTS
MODES OF OPERATION
POWER MANAGEMENT
FULL SPEED
USB
USB ENDPOINT TRANSCEIVER
RAM
8-/16-BIT
SERIAL PERIPHERAL
INTERFACE MODULE (SPI2)
SERIAL COMMUNICATIONS
INTERFACE MODULE (SCI2)
COP
IRQ
LVD
IIC MODULE (IIC)
VDDAD
USER FLASH (IN BYTES)
MC9S08JM16 = 16,384
MC9S08JM8 = 8,192
SS2
SPSCK2
MOSI2
MISO2
RxD2
TxD2
SDA
SCL
6
ANALOG COMPARATOR
(ACMP)
ACMP+
8-/16-BIT
SERIAL PERIPHERAL
INTERFACE MODULE (SPI1)
SPSCK1
ACMPO
VSS
VUSB33
SYSTEM
VOLTAGE
REGULATOR
INTERFACE MODULE (SCI1)
2-CHANNEL TIMER/PWM
MODULE (TPM2)
REAL-TIME COUNTER
(RTC)
7-BIT KEYBOARD
INTERRUPT MODULE (KBI)
PTE5/MOSI1
MISO1
PTE4/MISO1
PORT E
TPMCLK
TPM1CH1
2
PTE3/TPM1CH1
PTE2/TPM1CH0
RxD1
TxD1
PTE1/RxD1
PTE0/TxD1
TPMCLK
TPM2CH1
TPM2CH0
PTF6
PTF5/TPM2CH1
PTF4/TPM2CH0
KBIPx
USB 3.3 V VOLTAGE REGULATOR
PTE6/SPSCK1
MOSI1
TPM1CH0
TPM1CHx
PTD2/KBIP2/ACMPO
PTE7/SS1
KBIPx
PORT F
VDD
LOW-POWER OSCILLATOR
SERIAL COMMUNICATIONS
PTC5/RxD2
PTC4
PTC3/TxD2
PTC2
PTD1/ADP9/ACMP–
PTD0/ADP8/ACMP+
3
PTF1/TPM1CH3
PTF0/TPM1CH2
4
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 must not be driven above VDD.
4. Pin contains integrated pullup device.
5. When pin functions as KBI (KBIPEn = 1) and associated pin is configured to enable the
pullup device, KBEDGn can be used to reconfigure the pullup as a pulldown device.
PTG5/EXTAL
PORT G
VSSOSC
MODULE (TPM1)
PTB5/KBIP5/ADP5
PTB4/KBIP4/ADP4
PTB3/SS2/ADP3
PTB2/SPSCK2/ADP2
PTB1/MOSI2/ADP1
PTB0/MISO2/ADP0
PTD7
ACMP–
4-CHANNEL TIMER/PWM
MULTI-PURPOSE CLOCK
GENERATOR (MCG)
PTA5, PTA0
2
SS1
USER RAM (IN BYTES)
1024
2
PTC1/SDA
PTC0/SCL
PORT D
8-CHANNEL, 12-BIT
ANALOG-TO-DIGITAL
CONVERTER (ADC)
VSSAD
VREFL
VREFH
PORT B
BDC
PORT C
RESET
PORT A
HCS08 CORE
BKGD/MS
USBDP
USBDN
ON-CHIP ICE AND
DEBUG MODULE (DBG)
PTG4/XTAL
PTG3/KBIP7
PTG2/KBIP6
PTG1/KBIP1
PTG0/KBIP0
Figure 12-1. MC9S08JM16 Series Block Diagram Highlighting MCG Block and Pins
MC9S08JM16 Series Data Sheet, Rev. 2
178
Freescale Semiconductor
Multi-Purpose Clock Generator (S08MCGV1)
12.1.1
Features
Key features of the MCG module are:
• Frequency-locked loop (FLL)
— 0.2% resolution using internal 32 kHz reference
— 2% deviation over voltage and temperature using internal 32 kHz reference
— Internal or external reference can be used to control the FLL
• Phase-locked loop (PLL)
— Voltage-controlled oscillator (VCO)
— Modulo VCO frequency divider
— Phase/Frequency detector
— Integrated loop filter
— Lock detector with interrupt capability
• Internal reference clock
— Nine trim bits for accuracy
— Can be selected as the clock source for the MCU
• External reference clock
— Control for external oscillator
— Clock monitor with reset capability
— Can be selected as the clock source for the MCU
• Reference divider is provided
• Clock source selected can be divided down by 1, 2, 4, or 8
• BDC clock (MCGLCLK) is provided as a constant divide by 2 of the DCO output whether in an
FLL or PLL mode.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
179
Multi-Purpose Clock Generator (S08MCGV1)
External Oscillator
(XOSC)
RANGE
EREFS
ERCLKEN
MCGERCLK
HGO
EREFSTEN
IRCLKEN
MCGIRCLK
CME
IREFSTEN
CLKS
Clock
Monitor
LOC
BDIV
/ 2n
Internal
Reference
Clock
OSCINIT
9
IREFS
MCGOUT
n=0-3
LP
DCO
DCOOUT
TRIM
PLLS
/2
n
RDIV_CLK
Lock
Detector
Filter
n=0-7
FLL
LOLS LOCK
MCGFFCLK
RDIV
LP
VCOOUT
Phase
Detector
Charge
Pump
VDIV
Internal
Filter
MCGLCLK
/2
VCO
PLL
/(4,8,12,...,40)
Multi-purpose Clock Generator (MCG)
Figure 12-2. Multi-Purpose Clock Generator (MCG) Block Diagram
MC9S08JM16 Series Data Sheet, Rev. 2
180
Freescale Semiconductor
Multi-Purpose Clock Generator (S08MCGV1)
12.1.2
Modes of Operation
There are nine modes of operation for the MCG:
• FLL Engaged Internal (FEI)
• FLL Engaged External (FEE)
• FLL Bypassed Internal (FBI)
• FLL Bypassed External (FBE)
• PLL Engaged External (PEE)
• PLL Bypassed External (PBE)
• Bypassed Low Power Internal (BLPI)
• Bypassed Low Power External (BLPE)
• Stop
For details see Section 12.4.1, “Operational Modes.”
12.2
External Signal Description
There are no MCG signals that connect off chip.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
181
Multi-Purpose Clock Generator (S08MCGV1)
12.3
Register Definition
12.3.1
MCG Control Register 1 (MCGC1)
7
6
5
4
3
2
1
0
IREFS
IRCLKEN
IREFSTEN
1
0
0
R
CLKS
RDIV
W
Reset:
0
0
0
0
0
Figure 12-3. MCG Control Register 1 (MCGC1)
Table 12-1. MCG Control Register 1 Field Descriptions
Field
Description
7:6
CLKS
Clock Source Select — Selects the system clock source.
00 Encoding 0 — Output of FLL or PLL is selected.
01 Encoding 1 — Internal reference clock is selected.
10 Encoding 2 — External reference clock is selected.
11 Encoding 3 — Reserved, defaults to 00.
5:3
RDIV
Reference Divider — Selects the amount to divide down the reference clock selected by the IREFS bit. If the
FLL is selected, the resulting frequency must be in the range 31.25 kHz to 39.0625 kHz. If the PLL is selected,
the resulting frequency must be in the range 1 MHz to 2 MHz.
000 Encoding 0 — Divides reference clock by 1 (reset default)
001 Encoding 1 — Divides reference clock by 2
010 Encoding 2 — Divides reference clock by 4
011 Encoding 3 — Divides reference clock by 8
100 Encoding 4 — Divides reference clock by 16
101 Encoding 5 — Divides reference clock by 32
110 Encoding 6 — Divides reference clock by 64
111 Encoding 7 — Divides reference clock by 128
2
IREFS
Internal Reference Select — Selects the reference clock source.
1 Internal reference clock selected
0 External reference clock selected
1
IRCLKEN
0
IREFSTEN
Internal Reference Clock Enable — Enables the internal reference clock for use as MCGIRCLK.
1 MCGIRCLK active
0 MCGIRCLK inactive
Internal Reference Stop Enable — Controls whether or not the internal reference clock remains enabled when
the MCG enters stop mode.
1 Internal reference clock stays enabled in stop if IRCLKEN is set or if MCG is in FEI, FBI, or BLPI mode before
entering stop
0 Internal reference clock is disabled in stop
MC9S08JM16 Series Data Sheet, Rev. 2
182
Freescale Semiconductor
Multi-Purpose Clock Generator (S08MCGV1)
12.3.2
MCG Control Register 2 (MCGC2)
7
6
5
4
3
2
RANGE
HGO
LP
EREFS
0
0
0
0
1
0
R
BDIV
ERCLKEN EREFSTEN
W
Reset:
0
1
0
0
Figure 12-4. MCG Control Register 2 (MCGC2)
Table 12-2. MCG Control Register 2 Field Descriptions
Field
Description
7:6
BDIV
Bus Frequency Divider — Selects the amount to divide down the clock source selected by the CLKS bits in the
MCGC1 register. This controls the bus frequency.
00 Encoding 0 — Divides selected clock by 1
01 Encoding 1 — Divides selected clock by 2 (reset default)
10 Encoding 2 — Divides selected clock by 4
11 Encoding 3 — Divides selected clock by 8
5
RANGE
Frequency Range Select — Selects the frequency range for the external oscillator or external clock source.
1 High frequency range selected for the external oscillator of 1 MHz to 16 MHz (1 MHz to 40 MHz for external
clock source)
0 Low frequency range selected for the external oscillator of 32 kHz to 100 kHz (32 kHz to 1 MHz for external
clock source)
4
HGO
3
LP
2
EREFS
1
ERCLKEN
High Gain Oscillator Select — Controls the external oscillator mode of operation.
1 Configure external oscillator for high gain operation
0 Configure external oscillator for low power operation
Low Power Select — Controls whether the FLL (or PLL) is disabled in bypassed modes.
1 FLL (or PLL) is disabled in bypass modes (lower power).
0 FLL (or PLL) is not disabled in bypass modes.
External Reference Select — Selects the source for the external reference clock.
1 Oscillator requested
0 External Clock Source requested
External Reference Enable — Enables the external reference clock for use as MCGERCLK.
1 MCGERCLK active
0 MCGERCLK inactive
0
External Reference Stop Enable — Controls whether or not the external reference clock remains enabled when
EREFSTEN the MCG enters stop mode.
1 External reference clock stays enabled in stop if ERCLKEN is set or if MCG is in FEE, FBE, PEE, PBE, or
BLPE mode before entering stop
0 External reference clock is disabled in stop
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
183
Multi-Purpose Clock Generator (S08MCGV1)
12.3.3
MCG Trim Register (MCGTRM)
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
Figure 12-5. MCG Trim Register (MCGTRM)
Table 12-3. MCG Trim Register Field Descriptions
Field
Description
7:0
TRIM
MCG Trim Setting — Controls the internal reference clock frequency by controlling the internal reference clock
period. The TRIM bits are binary weighted (i.e., bit 1 will adjust twice as much as bit 0). Increasing the binary
value in TRIM will increase the period, and decreasing the value will decrease the period.
An additional fine trim bit is available in MCGSC as the FTRIM bit.
If a TRIM[7:0] value stored in nonvolatile memory is to be used, it’s the user’s responsibility to copy that value
from the nonvolatile memory location to this register.
MC9S08JM16 Series Data Sheet, Rev. 2
184
Freescale Semiconductor
Multi-Purpose Clock Generator (S08MCGV1)
12.3.4
MCG Status and Control Register (MCGSC)
R
7
6
5
4
3
LOLS
LOCK
PLLST
IREFST
2
CLKST
1
0
OSCINIT
FTRIM
W
POR:
Reset:
0
0
0
0
0
0
1
1
0
0
0
0
0
0
0
U
Figure 12-6. MCG Status and Control Register (MCGSC)
Table 12-4. MCG Status and Control Register Field Descriptions
Field
Description
7
LOLS
Loss of Lock Status — This bit is a sticky indication of lock status for the FLL or PLL. LOLS is set when lock
detection is enabled and after acquiring lock, the FLL or PLL output frequency has fallen outside the lock exit
frequency tolerance, Dunl. LOLIE determines whether an interrupt request is made when set. LOLS is cleared by
reset or by writing a logic 1 to LOLS when LOLS is set. Writing a logic 0 to LOLS has no effect.
0 FLL or PLL has not lost lock since LOLS was last cleared.
1 FLL or PLL has lost lock since LOLS was last cleared.
6
LOCK
Lock Status — Indicates whether the FLL or PLL has acquired lock. Lock detection is disabled when both the
FLL and PLL are disabled. If the lock status bit is set then changing the value of any of the following bits IREFS,
PLLS, RDIV[2:0], TRIM[7:0] (if in FEI or FBI modes), or VDIV[3:0] (if in PBE or PEE modes), will cause the lock
status bit to clear and stay cleared until the FLL or PLL has reacquired lock. Stop mode entry will also cause the
lock status bit to clear and stay cleared until the FLL or PLL has reacquired lock. Entry into BLPI or BLPE mode
will also cause the lock status bit to clear and stay cleared until the MCG has exited these modes and the FLL or
PLL has reacquired lock.
0 FLL or PLL is currently unlocked.
1 FLL or PLL is currently locked.
5
PLLST
PLL Select Status — The PLLST bit indicates the current source for the PLLS clock. The PLLST bit does not
update immediately after a write to the PLLS bit due to internal synchronization between clock domains.
0 Source of PLLS clock is FLL clock.
1 Source of PLLS clock is PLL clock.
4
IREFST
Internal Reference Status — The IREFST bit indicates the current source for the reference clock. The IREFST
bit does not update immediately after a write to the IREFS bit due to internal synchronization between clock
domains.
0 Source of reference clock is external reference clock (oscillator or external clock source as determined by the
EREFS bit in the MCGC2 register).
1 Source of reference clock is internal reference clock.
3:2
CLKST
Clock Mode Status — The CLKST bits indicate the current clock mode. The CLKST bits do not update
immediately after a write to the CLKS bits due to internal synchronization between clock domains.
00 Encoding 0 — Output of FLL is selected.
01 Encoding 1 — Internal reference clock is selected.
10 Encoding 2 — External reference clock is selected.
11 Encoding 3 — Output of PLL is selected.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
185
Multi-Purpose Clock Generator (S08MCGV1)
Table 12-4. MCG Status and Control Register Field Descriptions (continued)
Field
Description
1
OSCINIT
OSC Initialization — If the external reference clock is selected by ERCLKEN or by the MCG being in FEE, FBE,
PEE, PBE, or BLPE mode, and if EREFS is set, then this bit is set after the initialization cycles of the external
oscillator clock have completed. This bit is only cleared when either EREFS is cleared or when the MCG is in
either FEI, FBI, or BLPI mode and ERCLKEN is cleared.
0
FTRIM
MCG Fine Trim — Controls the smallest adjustment of the internal reference clock frequency. Setting FTRIM will
increase the period and clearing FTRIM will decrease the period by the smallest amount possible.
If an FTRIM value stored in nonvolatile memory is to be used, it’s the user’s responsibility to copy that value from
the nonvolatile memory location to this register’s FTRIM bit.
12.3.5
MCG Control Register 3 (MCGC3)
7
6
5
LOLIE
PLLS
CME
0
0
0
R
4
3
2
1
0
0
1
0
VDIV
W
Reset:
0
0
0
Figure 12-7. MCG PLL Register (MCGPLL)
Table 12-5. MCG PLL Register Field Descriptions
Field
Description
7
LOLIE
Loss of Lock Interrupt Enable — Determines if an interrupt request is made following a loss of lock indication.
The LOLIE bit only has an effect when LOLS is set.
0 No request on loss of lock.
1 Generate an interrupt request on loss of lock.
6
PLLS
PLL Select — Controls whether the PLL or FLL is selected. If the PLLS bit is clear, the PLL is disabled in all
modes. If the PLLS is set, the FLL is disabled in all modes.
1 PLL is selected
0 FLL is selected
MC9S08JM16 Series Data Sheet, Rev. 2
186
Freescale Semiconductor
Multi-Purpose Clock Generator (S08MCGV1)
Table 12-5. MCG PLL Register Field Descriptions (continued)
Field
Description
5
CME
Clock Monitor Enable — Determines if a reset request is made following a loss of external clock indication. The
CME bit must only be set to a logic 1 when either the MCG is in an operational mode that uses the external clock
(FEE, FBE, PEE, PBE, or BLPE) or the external reference is enabled (ERCLKEN=1 in the MCGC2 register).
Whenever the CME bit is set to a logic 1, the value of the RANGE bit in the MCGC2 register must not be changed.
0 Clock monitor is disabled.
1 Generate a reset request on loss of external clock.
3:0
VDIV
VCO Divider — Selects the amount to divide down the VCO output of PLL. The VDIV bits establish the
multiplication factor (M) applied to the reference clock frequency.
0000 Encoding 0 — Reserved.
0001 Encoding 1 — Multiply by 4.
0010 Encoding 2 — Multiply by 8.
0011 Encoding 3 — Multiply by 12.
0100 Encoding 4 — Multiply by 16.
0101 Encoding 5 — Multiply by 20.
0110 Encoding 6 — Multiply by 24.
0111 Encoding 7 — Multiply by 28.
1000 Encoding 8 — Multiply by 32.
1001 Encoding 9 — Multiply by 36.
1010 Encoding 10 — Multiply by 40.
1011 Encoding 11 — Reserved (default to M=40).
11xx Encoding 12-15 — Reserved (default to M=40).
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
187
Multi-Purpose Clock Generator (S08MCGV1)
12.4
Functional Description
12.4.1
Operational Modes
IREFS=1
CLKS=00
PLLS=0
FLL Engaged
Internal (FEI)
IREFS=1
CLKS=01
PLLS=0
BDM Enabled
or LP=0
FLL Engaged
External (FEE)
FLL Bypassed
Internal (FBI)
FLL Bypassed
External (FBE)
IREFS=0
CLKS=00
PLLS=0
IREFS=0
CLKS=10
PLLS=0
BDM Enabled
or LP=0
IREFS=0
CLKS=10
BDM Disabled
and LP=1
Bypassed
Low Power
External (BLPE)
Bypassed
IREFS=1
Low Power
CLKS=01
Internal (BLPI)
BDM Disabled
and LP=1
Entered from any state
when MCU enters stop
PLL Bypassed
External (PBE)
IREFS=0
CLKS=10
PLLS=1
BDM Enabled
or LP=0
PLL Engaged
External (PEE)
IREFS=0
CLKS=00
PLLS=1
Stop
Returns to state that was active
before MCU entered stop, unless
RESET occurs while in stop.
Figure 12-8. Clock Switching Modes
The nine states of the MCG are shown as a state diagram and are described below. The arrows indicate the
allowed movements between the states.
12.4.1.1
FLL Engaged Internal (FEI)
FLL engaged internal (FEI) is the default mode of operation and is entered when all the following
conditions occur:
• CLKS bits are written to 00
• IREFS bit is written to 1
• PLLS bit is written to 0
• RDIV bits are written to 000. Because the internal reference clock frequency must already be in
the range of 31.25 kHz to 39.0625 kHz after it is trimmed, no further frequency divide is necessary.
MC9S08JM16 Series Data Sheet, Rev. 2
188
Freescale Semiconductor
Multi-Purpose Clock Generator (S08MCGV1)
In FLL engaged internal mode, the MCGOUT clock is derived from the FLL clock, which is controlled by
the internal reference clock. The FLL clock frequency locks to 1024 times the reference frequency, as
selected by the RDIV bits. The MCGLCLK is derived from the FLL and the PLL is disabled in a low
power state.
12.4.1.2
FLL Engaged External (FEE)
The FLL engaged external (FEE) mode is entered when all the following conditions occur:
•
•
•
•
CLKS bits are written to 00
IREFS bit is written to 0
PLLS bit is written to 0
RDIV bits are written to divide reference clock to be within the range of 31.25 kHz to 39.0625 kHz
In FLL engaged external mode, the MCGOUT clock is derived from the FLL clock which is controlled by
the external reference clock. The external reference clock which is enabled can be an external
crystal/resonator or it can be another external clock source.The FLL clock frequency locks to 1024 times
the reference frequency, as selected by the RDIV bits. The MCGLCLK is derived from the FLL and the
PLL is disabled in a low power state.
12.4.1.3
FLL Bypassed Internal (FBI)
In FLL bypassed internal (FBI) mode, the MCGOUT clock is derived from the internal reference clock
and the FLL is operational but its output clock is not used. This mode is useful to allow the FLL to acquire
its target frequency while the MCGOUT clock is driven from the internal reference clock.
The FLL bypassed internal mode is entered when all the following conditions occur:
• CLKS bits are written to 01
• IREFS bit is written to 1
• PLLS bit is written to 0
• RDIV bits are written to 000. Since the internal reference clock frequency must already be in the
range of 31.25 kHz to 39.0625 kHz after it is trimmed, no further frequency divide is necessary.
• LP bit is written to 0
In FLL bypassed internal mode, the MCGOUT clock is derived from the internal reference clock. The FLL
clock is controlled by the internal reference clock, and the FLL clock frequency locks to 1024 times the
reference frequency, as selected by the RDIV bits. The MCGLCLK is derived from the FLL and the PLL
is disabled in a low power state.
12.4.1.4
FLL Bypassed External (FBE)
In FLL bypassed external (FBE) mode, the MCGOUT clock is derived from the external reference clock
and the FLL is operational but its output clock is not used. This mode is useful to allow the FLL to acquire
its target frequency while the MCGOUT clock is driven from the external reference clock.
The FLL bypassed external mode is entered when all the following conditions occur:
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
189
Multi-Purpose Clock Generator (S08MCGV1)
•
•
•
•
•
CLKS bits are written to 10
IREFS bit is written to 0
PLLS bit is written to 0
RDIV bits are written to divide reference clock to be within the range of 31.25 kHz to 39.0625 kHz
LP bit is written to 0
In FLL bypassed external mode, the MCGOUT clock is derived from the external reference clock. The
external reference clock which is enabled can be an external crystal/resonator or it can be another external
clock source.The FLL clock is controlled by the external reference clock, and the FLL clock frequency
locks to 1024 times the reference frequency, as selected by the RDIV bits. The MCGLCLK is derived from
the FLL and the PLL is disabled in a low power state.
NOTE
It is possible to briefly operate in FBE mode with an FLL reference clock
frequency that is greater than the specified maximum frequency. This can be
necessary in applications that operate in PEE mode using an external crystal
with a frequency above 5 MHz. Please see 12.5.2.4, “Example # 4: Moving
from FEI to PEE Mode: External Crystal = 8 MHz, Bus Frequency = 8 MHz
for a detailed example.
12.4.1.5
PLL Engaged External (PEE)
The PLL engaged external (PEE) mode is entered when all the following conditions occur:
•
•
•
•
CLKS bits are written to 00
IREFS bit is written to 0
PLLS bit is written to 1
RDIV bits are written to divide reference clock to be within the range of 1 MHz to 2 MHz
In PLL engaged external mode, the MCGOUT clock is derived from the PLL clock which is controlled by
the external reference clock. The external reference clock which is enabled can be an external
crystal/resonator or it can be another external clock source The PLL clock frequency locks to a
multiplication factor, as selected by the VDIV bits, times the reference frequency, as selected by the RDIV
bits. If BDM is enabled then the MCGLCLK is derived from the DCO (open-loop mode) divided by two.
If BDM is not enabled then the FLL is disabled in a low power state.
MC9S08JM16 Series Data Sheet, Rev. 2
190
Freescale Semiconductor
Multi-Purpose Clock Generator (S08MCGV1)
12.4.1.6
PLL Bypassed External (PBE)
In PLL bypassed external (PBE) mode, the MCGOUT clock is derived from the external reference clock
and the PLL is operational but its output clock is not used. This mode is useful to allow the PLL to acquire
its target frequency while the MCGOUT clock is driven from the external reference clock.
The PLL bypassed external mode is entered when all the following conditions occur:
•
•
•
•
•
CLKS bits are written to 10
IREFS bit is written to 0
PLLS bit is written to 1
RDIV bits are written to divide reference clock to be within the range of 1 MHz to 2 MHz
LP bit is written to 0
In PLL bypassed external mode, the MCGOUT clock is derived from the external reference clock. The
external reference clock which is enabled can be an external crystal/resonator or it can be another external
clock source. The PLL clock frequency locks to a multiplication factor, as selected by the VDIV bits, times
the reference frequency, as selected by the RDIV bits. If BDM is enabled then the MCGLCLK is derived
from the DCO (open-loop mode) divided by two. If BDM is not enabled then the FLL is disabled in a low
power state.
12.4.1.7
Bypassed Low Power Internal (BLPI)
The bypassed low power internal (BLPI) mode is entered when all the following conditions occur:
• CLKS bits are written to 01
• IREFS bit is written to 1
• PLLS bit is written to 0 or 1
• LP bit is written to 1
• BDM mode is not active
In bypassed low power internal mode, the MCGOUT clock is derived from the internal reference clock.
The PLL and the FLL are disabled at all times in BLPI mode and the MCGLCLK will not be available for
BDC communications If the BDM becomes active the mode will switch to one of the bypassed internal
modes as determined by the state of the PLLS bit.
12.4.1.8
Bypassed Low Power External (BLPE)
The bypassed low power external (BLPE) mode is entered when all the following conditions occur:
• CLKS bits are written to 10
• IREFS bit is written to 0
• PLLS bit is written to 0 or 1
• LP bit is written to 1
• BDM mode is not active
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
191
Multi-Purpose Clock Generator (S08MCGV1)
In bypassed low power external mode, the MCGOUT clock is derived from the external reference clock.
The external reference clock which is enabled can be an external crystal/resonator or it can be another
external clock source.
The PLL and the FLL are disabled at all times in BLPE mode and the MCGLCLK will not be available
for BDC communications. If the BDM becomes active the mode will switch to one of the bypassed
external modes as determined by the state of the PLLS bit.
12.4.1.9
Stop
Stop mode is entered whenever the MCU enters a STOP state. In this mode, the FLL and PLL are disabled
and all MCG clock signals are static except in the following cases:
MCGIRCLK will be active in stop mode when all the following conditions occur:
• IRCLKEN = 1
• IREFSTEN = 1
MCGERCLK will be active in stop mode when all the following conditions occur:
• ERCLKEN = 1
• EREFSTEN = 1
12.4.2
Mode Switching
When switching between engaged internal and engaged external modes the IREFS bit can be changed at
anytime, but the RDIV bits must be changed simultaneously so that the reference frequency stays in the
range required by the state of the PLLS bit (31.25 kHz to 39.0625 kHz if the FLL is selected, or 1 MHz to
2 MHz if the PLL is selected). After a change in the IREFS value the FLL or PLL will begin locking again
after the switch is completed. The completion of the switch is shown by the IREFST bit.
For the special case of entering stop mode immediately after switching to FBE mode, if the external clock
and the internal clock are disabled in stop mode, (EREFSTEN = 0 and IREFSTEN = 0), it is necessary to
allow 100us after the IREFST bit is cleared to allow the internal reference to shutdown. For most cases the
delay due to instruction execution times will be sufficient.
The CLKS bits can also be changed at anytime, but in order for the MCGLCLK to be configured correctly
the RDIV bits must be changed simultaneously so that the reference frequency stays in the range required
by the state of the PLLS bit (31.25 kHz to 39.0625 kHz if the FLL is selected, or 1 MHz to 2MHz if the
PLL is selected). The actual switch to the newly selected clock will be shown by the CLKST bits. If the
newly selected clock is not available, the previous clock will remain selected.
For details see Figure 12-8.
12.4.3
Bus Frequency Divider
The BDIV bits can be changed at anytime and the actual switch to the new frequency will occur
immediately.
MC9S08JM16 Series Data Sheet, Rev. 2
192
Freescale Semiconductor
Multi-Purpose Clock Generator (S08MCGV1)
12.4.4
Low Power Bit Usage
The low power bit (LP) is provided to allow the FLL or PLL to be disabled and thus conserve power when
these systems are not being used. However, in some applications it may be desirable to enable the FLL or
PLL and allow it to lock for maximum accuracy before switching to an engaged mode. Do this by writing
the LP bit to 0.
12.4.5
Internal Reference Clock
When IRCLKEN is set the internal reference clock signal will be presented as MCGIRCLK, which can be
used as an additional clock source. The MCGIRCLK frequency can be re-targeted by trimming the period
of the internal reference clock. This can be done by writing a new value to the TRIM bits in the MCGTRM
register. Writing a larger value will decrease the MCGIRCLK frequency, and writing a smaller value to
the MCGTRM register will increase the MCGIRCLK frequency. The TRIM bits will effect the MCGOUT
frequency if the MCG is in FLL engaged internal (FEI), FLL bypassed internal (FBI), or bypassed low
power internal (BLPI) mode. The TRIM and FTRIM value is initialized by POR but is not affected by
other resets.
Until MCGIRCLK is trimmed, programming low reference divider (RDIV) factors may result in
MCGOUT frequencies that exceed the maximum chip-level frequency and violate the chip-level clock
timing specifications (see the Device Overview chapter).
If IREFSTEN and IRCLKEN bits are both set, the internal reference clock will keep running during stop
mode in order to provide a fast recovery upon exiting stop.
12.4.6
External Reference Clock
The MCG module can support an external reference clock with frequencies between 31.25 kHz to 5 MHz
in FEE and FBE modes, 1 MHz to 16 MHz in PEE and PBE modes, and 0 to 40 MHz in BLPE mode.
When ERCLKEN is set, the external reference clock signal will be presented as MCGERCLK, which can
be used as an additional clock source. When IREFS = 1, the external reference clock will not be used by
the FLL or PLL and will only be used as MCGERCLK. In these modes, the frequency can be equal to the
maximum frequency the chip-level timing specifications will support (see the Device Overview chapter).
If EREFSTEN and ERCLKEN bits are both set or the MCG is in FEE, FBE, PEE, PBE or BLPE mode,
the external reference clock will keep running during stop mode in order to provide a fast recovery upon
exiting stop.
If CME bit is written to 1, the clock monitor is enabled. If the external reference falls below a certain
frequency (floc_high or floc_low depending on the RANGE bit in the MCGC2), the MCU will reset. The
LOC bit in the System Reset Status (SRS) register will be set to indicate the error.
12.4.7
Fixed Frequency Clock
The MCG presents the divided reference clock as MCGFFCLK for use as an additional clock source. The
MCGFFCLK frequency must be no more than 1/4 of the MCGOUT frequency to be valid. Because of this
requirement, the MCGFFCLK is not valid in bypass modes for the following combinations of BDIV and
RDIV values:
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
193
Multi-Purpose Clock Generator (S08MCGV1)
•
BDIV=00 (divide by 1), RDIV < 010
BDIV=01 (divide by 2), RDIV < 011
12.5
Initialization / Application Information
This section describes how to initialize and configure the MCG module in application. The following
sections include examples on how to initialize the MCG and properly switch between the various available
modes.
12.5.1
MCG Module Initialization Sequence
The MCG comes out of reset configured for FEI mode with the BDIV set for divide-by-2. The internal
reference will stabilize in tirefst microseconds before the FLL can acquire lock. As soon as the internal
reference is stable, the FLL will acquire lock in tfll_lock milliseconds.
Upon POR, the internal reference will require trimming to guarantee an accurate clock. Freescale
recommends using FLASH location 0xFFAE for storing the fine trim bit, FTRIM in the MCGSC register,
and 0xFFAF for storing the 8-bit trim value in the MCGTRM register. The MCU will not automatically
copy the values in these FLASH locations to the respective registers. Therefore, user code must copy these
values from FLASH to the registers.
NOTE
The BDIV value must not be changed to divide-by-1 without first trimming
the internal reference. Failure to do so could result in the MCU running out
of specification.
12.5.1.1
Initializing the MCG
Because the MCG comes out of reset in FEI mode, the only MCG modes which can be directly switched
to upon reset are FEE, FBE, and FBI modes (see Figure 12-8). Reaching any of the other modes requires
first configuring the MCG for one of these three initial modes. Care must be taken to check relevant status
bits in the MCGSC register reflecting all configuration changes within each mode.
To change from FEI mode to FEE or FBE modes, follow this procedure:
1. Enable the external clock source by setting the appropriate bits in MCGC2.
2. Write to MCGC1 to select the clock mode.
— If entering FEE, set RDIV appropriately, clear the IREFS bit to switch to the external reference,
and leave the CLKS bits at %00 so that the output of the FLL is selected as the system clock
source.
— If entering FBE, clear the IREFS bit to switch to the external reference and change the CLKS
bits to %10 so that the external reference clock is selected as the system clock source. The
RDIV bits must also be set appropriately here according to the external reference frequency
because although the FLL is bypassed, it is still on in FBE mode.
— The internal reference can optionally be kept running by setting the IRCLKEN bit. This is
useful if the application will switch back and forth between internal and external modes. For
MC9S08JM16 Series Data Sheet, Rev. 2
194
Freescale Semiconductor
Multi-Purpose Clock Generator (S08MCGV1)
minimum power consumption, leave the internal reference disabled while in an external clock
mode.
3. After the proper configuration bits have been set, wait for the affected bits in the MCGSC register
to be changed appropriately, reflecting that the MCG has moved into the proper mode.
— If ERCLKEN was set in step 1 or the MCG is in FEE, FBE, PEE, PBE, or BLPE mode, and
EREFS was also set in step 1, wait here for the OSCINIT bit to become set indicating that the
external clock source has finished its initialization cycles and stabilized. Typical crystal startup
times are given in Appendix A, “Electrical Characteristics”.
— If in FEE mode, check to make sure the IREFST bit is cleared and the LOCK bit is set before
moving on.
— If in FBE mode, check to make sure the IREFST bit is cleared, the LOCK bit is set, and the
CLKST bits have changed to %10 indicating the external reference clock has been
appropriately selected. Although the FLL is bypassed in FBE mode, it is still on and will lock
in FBE mode.
To change from FEI clock mode to FBI clock mode, follow this procedure:
1. Change the CLKS bits to %01 so that the internal reference clock is selected as the system clock
source.
2. Wait for the CLKST bits in the MCGSC register to change to %01, indicating that the internal
reference clock has been appropriately selected.
12.5.2
MCG Mode Switching
When switching between operational modes of the MCG, certain configuration bits must be changed in
order to properly move from one mode to another. Each time any of these bits are changed (PLLS, IREFS,
CLKS, or EREFS), the corresponding bits in the MCGSC register (PLLST, IREFST, CLKST, or
OSCINIT) must be checked before moving on in the application software.
Additionally, care must be taken to ensure that the reference clock divider (RDIV) is set properly for the
mode being switched to. For instance, in PEE mode, if using a 4 MHz crystal, RDIV must be set to %001
(divide-by-2) or %010 (divide-by-4) in order to divide the external reference down to the required
frequency between 1 and 2 MHz.
The RDIV and IREFS bits must always be set properly before changing the PLLS bit so that the FLL or
PLL clock has an appropriate reference clock frequency to switch to.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
195
Multi-Purpose Clock Generator (S08MCGV1)
The table below shows MCGOUT frequency calculations using RDIV, BDIV, and VDIV settings for each
clock mode. The bus frequency is equal to MCGOUT divided by 2.
Table 12-6. MCGOUT Frequency Calculation Options
fMCGOUT1
Clock Mode
Note
FEI (FLL engaged internal)
(fint * 1024) / B
Typical fMCGOUT = 16 MHz
immediately after reset. RDIV
bits set to %000.
FEE (FLL engaged external)
(fext / R *1024) / B
fext / R must be in the range of
31.25 kHz to 39.0625 kHz
FBE (FLL bypassed external)
fext / B
fext / R must be in the range of
31.25 kHz to 39.0625 kHz
FBI (FLL bypassed internal)
fint / B
Typical fint = 32 kHz
PEE (PLL engaged external)
[(fext / R) * M] / B
fext / R must be in the range of 1
MHz to 2 MHz
PBE (PLL bypassed external)
fext / B
fext / R must be in the range of 1
MHz to 2 MHz
BLPI (Bypassed low power internal)
fint / B
BLPE (Bypassed low power external)
fext / B
1R
is the reference divider selected by the RDIV bits, B is the bus frequency divider selected by the BDIV bits,
and M is the multiplier selected by the VDIV bits.
This section will include 3 mode switching examples using a 4 MHz external crystal. If using an external
clock source less than 1 MHz, the MCG must not be configured for any of the PLL modes (PEE and PBE).
12.5.2.1
Example # 1: Moving from FEI to PEE Mode: External Crystal = 4 MHz,
Bus Frequency = 8 MHz
In this example, the MCG will move through the proper operational modes from FEI to PEE mode until
the 4 MHz crystal reference frequency is set to achieve a bus frequency of 8 MHz. Because the MCG is in
FEI mode out of reset, this example also shows how to initialize the MCG for PEE mode out of reset. First,
the code sequence will be described. Then a flowchart will be included which illustrates the sequence.
1. First, FEI must transition to FBE mode:
a) MCGC2 = 0x36 (%00110110)
– BDIV (bits 7 and 6) set to %00, or divide-by-1
– RANGE (bit 5) set to 1 because the frequency of 4 MHz is within the high frequency range
– HGO (bit 4) set to 1 to configure external oscillator for high gain operation
– EREFS (bit 2) set to 1, because a crystal is being used
– ERCLKEN (bit 1) set to 1 to ensure the external reference clock is active
b) Loop until OSCINIT (bit 1) in MCGSC is 1, indicating the crystal selected by the EREFS bit
has been initialized.
c) MCGC1 = 0xB8 (%10111000)
MC9S08JM16 Series Data Sheet, Rev. 2
196
Freescale Semiconductor
Multi-Purpose Clock Generator (S08MCGV1)
– CLKS (bits 7 and 6) set to %10 in order to select external reference clock as system clock
source
– RDIV (bits 5-3) set to %111, or divide-by-128 because 4 MHz / 128 = 31.25 kHz which is
in the 31.25 kHz to 39.0625 kHz range required by the FLL
– IREFS (bit 2) cleared to 0, selecting the external reference clock
d) Loop until IREFST (bit 4) in MCGSC is 0, indicating the external reference is the current
source for the reference clock
e) Loop until CLKST (bits 3 and 2) in MCGSC are %10, indicating that the external reference
clock is selected to feed MCGOUT
2. Then, FBE must transition either directly to PBE mode or first through BLPE mode and then to
PBE mode:
a) BLPE: If a transition through BLPE mode is desired, first set LP (bit 3) in MCGC2 to 1.
b) BLPE/PBE: MCGC1 = 0x90 (%10010000)
– RDIV (bits 5-3) set to %010, or divide-by-4 because 4 MHz / 4 = 1 MHz which is in the 1
MHz to 2 MHz range required by the PLL. In BLPE mode, the configuration of the RDIV
does not matter because both the FLL and PLL are disabled. Changing them only sets up the
the dividers for PLL usage in PBE mode
c) BLPE/PBE: MCGC3 = 0x44 (%01000100)
– PLLS (bit 6) set to 1, selects the PLL. In BLPE mode, changing this bit only prepares the
MCG for PLL usage in PBE mode
– VDIV (bits 3-0) set to %0100, or multiply-by-16 because 1 MHz reference × 16 = 16 MHz.
In BLPE mode, the configuration of the VDIV bits does not matter because the PLL is
disabled. Changing them only sets up the multiply value for PLL usage in PBE mode
d) BLPE: If transitioning through BLPE mode, clear LP (bit 3) in MCGC2 to 0 here to switch to
PBE mode
e) PBE: Loop until PLLST (bit 5) in MCGSC is set, indicating that the current source for the
PLLS clock is the PLL
f) PBE: Then loop until LOCK (bit 6) in MCGSC is set, indicating that the PLL has acquired lock
3. Last, PBE mode transitions into PEE mode:
a) MCGC1 = 0x10 (%00010000)
– CLKS (bits7 and 6) in MCGSC1 set to %00 in order to select the output of the PLL as the
system clock source
– Loop until CLKST (bits 3 and 2) in MCGSC are %11, indicating that the PLL output is
selected to feed MCGOUT in the current clock mode
b) Now, With an RDIV of divide-by-4, a BDIV of divide-by-1, and a VDIV of multiply-by-16,
MCGOUT = [(4 MHz / 4) × 16] / 1 = 16 MHz, and the bus frequency is MCGOUT / 2, or 8
MHz
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
197
Multi-Purpose Clock Generator (S08MCGV1)
START
IN FEI MODE
MCGC2 = $36
IN
BLPE MODE ?
(LP=1)
CHECK
NO
NO
YES
OSCINIT = 1 ?
MCGC2 = $36
(LP = 0)
YES
MCGC1 = $B8
CHECK
PLLST = 1?
CHECK
NO
NO
YES
IREFST = 0?
YES
CHECK
LOCK = 1?
CHECK
CLKST = %10?
NO
NO
YES
MCGC1 = $10
YES
ENTER
BLPE MODE ?
NO
CHECK
CLKST = %11?
NO
YES
YES
MCGC2 = $3E
(LP = 1)
CONTINUE
IN PEE MODE
MCGC1 = $90
MCGC3 = $44
Figure 12-9. Flowchart of FEI to PEE Mode Transition using a 4 MHz Crystal
MC9S08JM16 Series Data Sheet, Rev. 2
198
Freescale Semiconductor
Multi-Purpose Clock Generator (S08MCGV1)
12.5.2.2
Example # 2: Moving from PEE to BLPI Mode: External Crystal = 4 MHz,
Bus Frequency =16 kHz
In this example, the MCG will move through the proper operational modes from PEE mode with a 4 MHz
crystal configured for an 8 MHz bus frequency (see previous example) to BLPI mode with a 16 kHz bus
frequency.First, the code sequence will be described. Then a flowchart will be included which illustrates
the sequence.
1. First, PEE must transition to PBE mode:
a) MCGC1 = 0x90 (%10010000)
– CLKS (bits 7 and 6) set to %10 in order to switch the system clock source to the external
reference clock
b) Loop until CLKST (bits 3 and 2) in MCGSC are %10, indicating that the external reference
clock is selected to feed MCGOUT
2. Then, PBE must transition either directly to FBE mode or first through BLPE mode and then to
FBE mode:
a) BLPE: If a transition through BLPE mode is desired, first set LP (bit 3) in MCGC2 to 1
b) BLPE/FBE: MCGC1 = 0xB8 (%10111000)
– RDIV (bits 5-3) set to %111, or divide-by-128 because 4 MHz / 128 = 31.25 kHz which is
in the 31.25 kHz to 39.0625 kHz range required by the FLL. In BLPE mode, the
configuration of the RDIV does not matter because both the FLL and PLL are disabled.
Changing them only sets up the dividers for FLL usage in FBE mode
c) BLPE/FBE: MCGC3 = 0x04 (%00000100)
– PLLS (bit 6) clear to 0 to select the FLL. In BLPE mode, changing this bit only prepares the
MCG for FLL usage in FBE mode. With PLLS = 0, the VDIV value does not matter.
d) BLPE: If transitioning through BLPE mode, clear LP (bit 3) in MCGC2 to 0 here to switch to
FBE mode
e) FBE: Loop until PLLST (bit 5) in MCGSC is clear, indicating that the current source for the
PLLS clock is the FLL
f) FBE: Optionally, loop until LOCK (bit 6) in the MCGSC is set, indicating that the FLL has
acquired lock. Although the FLL is bypassed in FBE mode, it is still enabled and running.
3. Next, FBE mode transitions into FBI mode:
a) MCGC1 = 0x44 (%01000100)
– CLKS (bits7 and 6) in MCGSC1 set to %01 in order to switch the system clock to the
internal reference clock
– IREFS (bit 2) set to 1 to select the internal reference clock as the reference clock source
– RDIV (bits 5-3) set to %000, or divide-by-1 because the trimmed internal reference must be
within the 31.25 kHz to 39.0625 kHz range required by the FLL
b) Loop until IREFST (bit 4) in MCGSC is 1, indicating the internal reference clock has been
selected as the reference clock source
c) Loop until CLKST (bits 3 and 2) in MCGSC are %01, indicating that the internal reference
clock is selected to feed MCGOUT
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
199
Multi-Purpose Clock Generator (S08MCGV1)
4. Lastly, FBI transitions into FBILP mode.
a) MCGC2 = 0x08 (%00001000)
– LP (bit 3) in MCGSC is 1
START
IN PEE MODE
MCGC1 = $90
CHECK
PLLST = 0?
CHECK
NO
CLKST = %10 ?
YES
YES
OPTIONAL:
CHECK LOCK
= 1?
ENTER
NO
NO
NO
BLPE MODE ?
YES
MCGC1 = $44
YES
MCGC2 = $3E
CHECK
IREFST = 0?
MCGC1 = $B8
MCGC3 = $04
IN
BLPE MODE ?
(LP=1)
NO
YES
NO
CHECK
CLKST = %01?
NO
YES
YES
MCGC2 = $36
(LP = 0)
MCGC2 = $08
CONTINUE
IN BLPI MODE
Figure 12-10. Flowchart of PEE to BLPI Mode Transition using a 4 MHz Crystal
MC9S08JM16 Series Data Sheet, Rev. 2
200
Freescale Semiconductor
Multi-Purpose Clock Generator (S08MCGV1)
12.5.2.3
Example #3: Moving from BLPI to FEE Mode: External Crystal = 4 MHz,
Bus Frequency = 16 MHz
In this example, the MCG will move through the proper operational modes from BLPI mode at a 16 kHz
bus frequency running off of the internal reference clock (see previous example) to FEE mode using a 4
MHz crystal configured for a 16 MHz bus frequency. First, the code sequence will be described. Then a
flowchart will be included which illustrates the sequence.
1. First, BLPI must transition to FBI mode.
a) MCGC2 = 0x00 (%00000000)
– LP (bit 3) in MCGSC is 0
b) Optionally, loop until LOCK (bit 6) in the MCGSC is set, indicating that the FLL has acquired
lock. Although the FLL is bypassed in FBI mode, it is still enabled and running.
2. Next, FBI will transition to FEE mode.
a) MCGC2 = 0x36 (%00110110)
– RANGE (bit 5) set to 1 because the frequency of 4 MHz is within the high frequency range
– HGO (bit 4) set to 1 to configure external oscillator for high gain operation
– EREFS (bit 2) set to 1, because a crystal is being used
– ERCLKEN (bit 1) set to 1 to ensure the external reference clock is active
b) Loop until OSCINIT (bit 1) in MCGSC is 1, indicating the crystal selected by the EREFS bit
has been initialized.
c) MCGC1 = 0x38 (%00111000)
– CLKS (bits 7 and 6) set to %00 in order to select the output of the FLL as system clock
source
– RDIV (bits 5-3) set to %111, or divide-by-128 because 4 MHz / 128 = 31.25 kHz which is
in the 31.25 kHz to 39.0625 kHz range required by the FLL
– IREFS (bit 1) cleared to 0, selecting the external reference clock
d) Loop until IREFST (bit 4) in MCGSC is 0, indicating the external reference clock is the current
source for the reference clock
e) Optionally, loop until LOCK (bit 6) in the MCGSC is set, indicating that the FLL has
reacquired lock.
f) Loop until CLKST (bits 3 and 2) in MCGSC are %00, indicating that the output of the FLL is
selected to feed MCGOUT
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
201
Multi-Purpose Clock Generator (S08MCGV1)
START
IN BLPI MODE
CHECK
NO
IREFST = 0?
MCGC2 = $00
YES
OPTIONAL:
CHECK LOCK
= 1?
NO
OPTIONAL:
CHECK LOCK
= 1?
NO
YES
YES
MCGC2 = $36
CHECK
CLKST = %00?
CHECK
NO
NO
YES
OSCINIT = 1 ?
CONTINUE
YES
IN FEE MODE
MCGC1 = $38
Figure 12-11. Flowchart of BLPI to FEE Mode Transition using a 4 MHz Crystal
12.5.2.4
Example # 4: Moving from FEI to PEE Mode: External Crystal = 8 MHz,
Bus Frequency = 8 MHz
In this example, the MCG will move through the proper operational modes from FEI to PEE mode until
the 8 MHz crystal reference frequency is set to achieve a bus frequency of 8 MHz.
This example is similar to example number one except that in this case the frequency of the external crystal
is 8 MHz instead of 4 MHz. Special consideration must be taken with this case since there is a period of
time along the way from FEI mode to PEE mode where the FLL operates based on a reference clock with
a frequency that is greater than the maximum allowed for the FLL. This occurs because with an 8 MHz
MC9S08JM16 Series Data Sheet, Rev. 2
202
Freescale Semiconductor
Multi-Purpose Clock Generator (S08MCGV1)
external crystal and a maximum reference divider factor of 128, the resulting frequency of the reference
clock for the FLL is 62.5 kHz (greater than the 39.0625 kHz maximum allowed).
Care must be taken in the software to minimize the amount of time spent in this state where the FLL is
operating in this condition.
The following code sequence describes how to move from FEI mode to PEE mode until the 8 MHz crystal
reference frequency is set to achieve a bus frequency of 8 MHz. Because the MCG is in FEI mode out of
reset, this example also shows how to initialize the MCG for PEE mode out of reset. First, the code
sequence will be described. Then a flowchart will be included which illustrates the sequence.
1. First, FEI must transition to FBE mode:
a) MCGC2 = 0x36 (%00110110)
– BDIV (bits 7 and 6) set to %00, or divide-by-1
– RANGE (bit 5) set to 1 because the frequency of 8 MHz is within the high frequency range
– HGO (bit 4) set to 1 to configure external oscillator for high gain operation
– EREFS (bit 2) set to 1, because a crystal is being used
– ERCLKEN (bit 1) set to 1 to ensure the external reference clock is active
b) Loop until OSCINIT (bit 1) in MCGSC is 1, indicating the crystal selected by the EREFS bit
has been initialized.
c) Block Interrupts (If applicable by setting the interrupt bit in the CCR).
d) MCGC1 = 0xB8 (%10111000)
– CLKS (bits 7 and 6) set to %10 in order to select external reference clock as system clock
source
– RDIV (bits 5-3) set to %111, or divide-by-128.
NOTE
8 MHz / 128 = 62.5 kHz which is greater than the 31.25 kHz to 39.0625 kHz
range required by the FLL. Therefore after the transition to FBE is
complete, software must progress through to BLPE mode immediately by
setting the LP bit in MCGC2.
– IREFS (bit 2) cleared to 0, selecting the external reference clock
e) Loop until IREFST (bit 4) in MCGSC is 0, indicating the external reference is the current
source for the reference clock
f) Loop until CLKST (bits 3 and 2) in MCGSC are %10, indicating that the external reference
clock is selected to feed MCGOUT
2. Then, FBE mode transitions into BLPE mode:
a) MCGC2 = 0x3E (%00111110)
– LP (bit 3) in MCGC2 to 1 (BLPE mode entered)
NOTE
There must be no extra steps (including interrupts) between steps 1d and 2a.
b) Enable Interrupts (if applicable by clearing the interrupt bit in the CCR).
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
203
Multi-Purpose Clock Generator (S08MCGV1)
c) MCGC1 = 0x98 (%10011000)
– RDIV (bits 5-3) set to %011, or divide-by-8 because 8 MHz / 8= 1 MHz which is in the 1
MHz to 2 MHz range required by the PLL. In BLPE mode, the configuration of the RDIV
does not matter because both the FLL and PLL are disabled. Changing them only sets up the
the dividers for PLL usage in PBE mode
d) MCGC3 = 0x44 (%01000100)
– PLLS (bit 6) set to 1, selects the PLL. In BLPE mode, changing this bit only prepares the
MCG for PLL usage in PBE mode
– VDIV (bits 3-0) set to %0100, or multiply-by-16 because 1 MHz reference * 16 = 16 MHz.
In BLPE mode, the configuration of the VDIV bits does not matter because the PLL is
disabled. Changing them only sets up the multiply value for PLL usage in PBE mode
e) Loop until PLLST (bit 5) in MCGSC is set, indicating that the current source for the PLLS
clock is the PLL
3. Then, BLPE mode transitions into PBE mode:
a) Clear LP (bit 3) in MCGC2 to 0 here to switch to PBE mode
b) Then loop until LOCK (bit 6) in MCGSC is set, indicating that the PLL has acquired lock
4. Last, PBE mode transitions into PEE mode:
a) MCGC1 = 0x18 (%00011000)
– CLKS (bits7 and 6) in MCGSC1 set to %00 in order to select the output of the PLL as the
system clock source
– Loop until CLKST (bits 3 and 2) in MCGSC are %11, indicating that the PLL output is
selected to feed MCGOUT in the current clock mode
b) Now, With an RDIV of divide-by-8, a BDIV of divide-by-1, and a VDIV of multiply-by-16,
MCGOUT = [(8 MHz / 8) × 16] / 1 = 16 MHz, and the bus frequency is MCGOUT / 2, or 8
MHz
MC9S08JM16 Series Data Sheet, Rev. 2
204
Freescale Semiconductor
Multi-Purpose Clock Generator (S08MCGV1)
START
IN FEI MODE
MCGC2 = $36
CHECK
NO
CHECK
PLLST = 1?
NO
OSCINIT = 1 ?
YES
YES
MCGC2 = $36
(LP = 0)
MCGC1 = $B8
CHECK
NO
IREFST = 0?
CHECK
LOCK = 1?
NO
YES
YES
CHECK
CLKST = %10?
NO
MCGC1 = $18
YES
CHECK
CLKST = %11?
MCGC2 = $3E
(LP = 1)
NO
YES
MCGC1 = $98
MCGC3 = $44
CONTINUE
IN PEE MODE
Figure 12-12. Flowchart of FEI to PEE Mode Transition using a 8 MHz Crystal
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
205
Multi-Purpose Clock Generator (S08MCGV1)
12.5.3
Calibrating the Internal Reference Clock (IRC)
The IRC is calibrated by writing to the MCGTRM register first, then using the FTRIM bit to “fine tune”
the frequency. We will refer to this total 9-bit value as the trim value, ranging from 0x000 to 0x1FF, where
the FTRIM bit is the LSB.
The trim value after a POR is always 0x100 (MCGTRM = 0x80 and FTRIM = 0). Writing a larger value
will decrease the frequency and smaller values will increase the frequency. The trim value is linear with
the period, except that slight variations in wafer fab processing produce slight non-linearities between trim
value and period. These non-linearities are why an iterative trimming approach to search for the best trim
value is recommended. In example #4 later in this section, this approach will be demonstrated.
After a trim value has been found for a device, this value can be stored in FLASH memory to save the
value. If power is removed from the device, the IRC can easily be re-trimmed by copying the saved value
from FLASH to the MCG registers. Freescale identifies recommended FLASH locations for storing the
trim value for each MCU. Consult the memory map in the data sheet for these locations. On devices that
are factory trimmed, the factory trim value will be stored in these locations.
12.5.3.1
Example #5: Internal Reference Clock Trim
For applications that require a tight frequency tolerance, a trimming procedure is provided that will allow
a very accurate internal clock source. This section outlines one example of trimming the internal oscillator.
Many other possible trimming procedures are valid and can be used.
In the example below, the MCG trim will be calibrated for the 9-bit MCGTRM and FTRIM collective
value. This value will be referred to as TRMVAL.
MC9S08JM16 Series Data Sheet, Rev. 2
206
Freescale Semiconductor
Multi-Purpose Clock Generator (S08MCGV1)
Initial conditions:
1) Clock supplied from ATE has 500 μs duty period
2) MCG configured for internal reference with 8MHz bus
START TRIM PROCEDURE
TRMVAL = $100
n=1
MEASURE
INCOMING CLOCK WIDTH
(COUNT = # OF BUS CLOCKS / 8)
COUNT < EXPECTED = 500
(RUNNING TOO SLOW)
.
CASE STATEMENT
COUNT = EXPECTED = 500
COUNT > EXPECTED = 500
(RUNNING TOO FAST)
TRMVAL =
TRMVAL - 256/ (2**n)
(DECREASING TRMVAL
INCREASES THE FREQUENCY)
TRMVAL =
TRMVAL + 256/ (2**n)
(INCREASING TRMVAL
DECREASES THE FREQUENCY)
STORE MCGTRM AND
FTRIM VALUES IN
NON-VOLATILE MEMORY
CONTINUE
n = n+1
IS n > 9?
YES
NO
Figure 12-13. 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 12-13 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 reference divider value (RDIV setting) of twice the final value. After the trim procedure is complete, the
reference divider can be restored. This will prevent accidental overshoot of the maximum clock frequency.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
207
Multi-Purpose Clock Generator (S08MCGV1)
MC9S08JM16 Series Data Sheet, Rev. 2
208
Freescale Semiconductor
Chapter 13
Real-Time Counter (S08RTCV1)
13.1
Introduction
The real-time counter (RTC) consists of one 8-bit counter, one 8-bit comparator, several binary-based and
decimal-based prescaler dividers, two clock sources, and one programmable periodic interrupt. This
module can be used for time-of-day, calendar or any task scheduling functions. It can also serve as a cyclic
wakeup from low power modes without the need for external components.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
209
Chapter 13 Real-Time Counter (S08RTCV1)
IRQ/TPMCLK
USB SIE
CPU
HCS08 SYSTEM CONTROL
RESETS AND INTERRUPTS
MODES OF OPERATION
POWER MANAGEMENT
FULL SPEED
USB
USB ENDPOINT TRANSCEIVER
RAM
8-/16-BIT
SERIAL PERIPHERAL
INTERFACE MODULE (SPI2)
SERIAL COMMUNICATIONS
INTERFACE MODULE (SCI2)
COP
IRQ
LVD
IIC MODULE (IIC)
VDDAD
USER FLASH (IN BYTES)
MC9S08JM16 = 16,384
MC9S08JM8 = 8,192
SS2
SPSCK2
MOSI2
MISO2
RxD2
TxD2
SDA
SCL
6
ANALOG COMPARATOR
(ACMP)
ACMP+
8-/16-BIT
SERIAL PERIPHERAL
INTERFACE MODULE (SPI1)
SPSCK1
ACMPO
VSS
VUSB33
SYSTEM
VOLTAGE
REGULATOR
INTERFACE MODULE (SCI1)
2-CHANNEL TIMER/PWM
MODULE (TPM2)
REAL-TIME COUNTER
(RTC)
7-BIT KEYBOARD
INTERRUPT MODULE (KBI)
PTE5/MOSI1
MISO1
PTE4/MISO1
PORT E
TPMCLK
TPM1CH1
2
PTE3/TPM1CH1
PTE2/TPM1CH0
RxD1
TxD1
PTE1/RxD1
PTE0/TxD1
TPMCLK
TPM2CH1
TPM2CH0
PTF6
PTF5/TPM2CH1
PTF4/TPM2CH0
KBIPx
USB 3.3 V VOLTAGE REGULATOR
PTE6/SPSCK1
KBIPx
EXTAL
XTAL
PORT F
VDD
LOW-POWER OSCILLATOR
SERIAL COMMUNICATIONS
PTE7/SS1
MOSI1
TPM1CH0
TPM1CHx
PTD2/KBIP2/ACMPO
PTD1/ADP9/ACMP–
PTD0/ADP8/ACMP+
3
PTF1/TPM1CH3
PTF0/TPM1CH2
4
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 must not be driven above VDD.
4. Pin contains integrated pullup device.
5. When pin functions as KBI (KBIPEn = 1) and associated pin is configured to enable the
pullup device, KBEDGn can be used to reconfigure the pullup as a pulldown device.
PTG5/EXTAL
PORT G
VSSOSC
MODULE (TPM1)
PTC5/RxD2
PTC4
PTC3/TxD2
PTC2
PTD7
ACMP–
4-CHANNEL TIMER/PWM
MULTI-PURPOSE CLOCK
GENERATOR (MCG)
PTB5/KBIP5/ADP5
PTB4/KBIP4/ADP4
PTB3/SS2/ADP3
PTB2/SPSCK2/ADP2
PTB1/MOSI2/ADP1
PTB0/MISO2/ADP0
2
SS1
USER RAM (IN BYTES)
1024
PTA5, PTA0
PTC1/SDA
PTC0/SCL
PORT D
8-CHANNEL, 12-BIT
ANALOG-TO-DIGITAL
CONVERTER (ADC)
VSSAD
VREFL
VREFH
PORT B
BDC
2
PORT C
RESET
PORT A
HCS08 CORE
BKGD/MS
USBDP
USBDN
ON-CHIP ICE AND
DEBUG MODULE (DBG)
PTG4/XTAL
PTG3/KBIP7
PTG2/KBIP6
PTG1/KBIP1
PTG0/KBIP0
Figure 13-1. MC9S08JM16 Series Block Diagram Highlighting RTC Block
MC9S08JM16 Series Data Sheet, Rev. 2
210
Freescale Semiconductor
Real-Time Counter (S08RTCV1)
13.1.1
Features
Features of the RTC module include:
• 8-bit up-counter
— 8-bit modulo match limit
— Software controllable periodic interrupt on match
• Three software selectable clock sources for input to prescaler with selectable binary-based and
decimal-based divider values
— 1 kHz internal low-power oscillator (LPO)
— External clock (ERCLK)
— 32 kHz internal clock (IRCLK)
13.1.2
Modes of Operation
This section defines the operation in stop, wait and background debug modes.
13.1.2.1
Wait Mode
The RTC continues to run in wait mode if enabled before executing the appropriate instruction. Therefore,
the RTC can bring the MCU out of wait mode if the real-time interrupt is enabled. For lowest possible
current consumption, the RTC must be stopped by software if not needed as an interrupt source during wait
mode.
13.1.2.2
Stop Modes
The RTC continues to run in stop2 or stop3 mode if the RTC is enabled before executing the STOP
instruction. Therefore, the RTC can bring the MCU out of stop modes with no external components, if the
real-time interrupt is enabled.
The LPO clock can be used in stop2 and stop3 modes. ERCLK and IRCLK clocks are only available in
stop3 mode.
Power consumption is lower when all clock sources are disabled, but in that case, the real-time interrupt
cannot wake up the MCU from stop modes.
13.1.2.3
Active Background Mode
The RTC suspends all counting during active background mode until the microcontroller returns to normal
user operating mode. Counting resumes from the suspended value as long as the RTCMOD register is not
written and the RTCPS and RTCLKS bits are not altered.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
211
Real-Time Counter (S08RTCV1)
13.1.3
Block Diagram
The block diagram for the RTC module is shown in Figure 13-2.
LPO
Clock
Source
Select
ERCLK
IRCLK
8-Bit Modulo
(RTCMOD)
RTCLKS
VDD
RTCLKS[0]
RTCPS
Prescaler
Divide-By
Q
D
Background
Mode
E
8-Bit Comparator
RTC
Clock
RTC
Interrupt
Request
RTIF
R
Write 1 to
RTIF
8-Bit Counter
(RTCCNT)
RTIE
Figure 13-2. Real-Time Counter (RTC) Block Diagram
13.2
External Signal Description
The RTC does not include any off-chip signals.
13.3
Register Definition
The RTC includes a status and control register, an 8-bit counter register, and an 8-bit modulo register.
Refer to the direct-page register summary in the memory section of this document for the absolute address
assignments for all RTC registers.This section refers to registers and control bits only by their names and
relative address offsets.
Table 13-1 is a summary of RTC registers.
Table 13-1. RTC Register Summary
Name
7
6
5
4
3
2
1
0
R
RTCSC
RTIF
RTCLKS
RTIE
RTCPS
W
R
RTCCNT
RTCCNT
W
R
RTCMOD
RTCMOD
W
MC9S08JM16 Series Data Sheet, Rev. 2
212
Freescale Semiconductor
Real-Time Counter (S08RTCV1)
13.3.1
RTC Status and Control Register (RTCSC)
RTCSC
contains the real-time interrupt status flag (RTIF), the clock select bits (RTCLKS), the real-time
interrupt enable bit (RTIE), and the prescaler select bits (RTCPS).
7
6
5
4
3
2
1
0
0
0
R
RTIF
RTCLKS
RTIE
RTCPS
W
Reset:
0
0
0
0
0
0
Figure 13-3. RTC Status and Control Register (RTCSC)
Table 13-2. RTCSC Field Descriptions
Field
Description
7
RTIF
Real-Time Interrupt Flag This status bit indicates the RTC counter register reached the value in the RTC modulo
register. Writing a logic 0 has no effect. Writing a logic 1 clears the bit and the real-time interrupt request. Reset
clears RTIF.
0 RTC counter has not reached the value in the RTC modulo register.
1 RTC counter has reached the value in the RTC modulo register.
6–5
RTCLKS
Real-Time Clock Source Select. These two read/write bits select the clock source input to the RTC prescaler.
Changing the clock source clears the prescaler and RTCCNT counters. When selecting a clock source, ensure
that the clock source is properly enabled (if applicable) to ensure correct operation of the RTC. Reset clears
RTCLKS.
00 Real-time clock source is the 1 kHz low power oscillator (LPO)
01 Real-time clock source is the external clock (ERCLK)
1x Real-time clock source is the internal clock (IRCLK)
4
RTIE
Real-Time Interrupt Enable. This read/write bit enables real-time interrupts. If RTIE is set, then an interrupt is
generated when RTIF is set. Reset clears RTIE.
0 Real-time interrupt requests are disabled. Use software polling.
1 Real-time interrupt requests are enabled.
3–0
RTCPS
Real-Time Clock Prescaler Select. These four read/write bits select binary-based or decimal-based divide-by
values for the clock source. See Table 13-3. Changing the prescaler value clears the prescaler and RTCCNT
counters. Reset clears RTCPS.
Table 13-3. RTC Prescaler Divide-by values
RTCPS
RTCLKS[0]
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
0
Off
23
25
26
27
28
29
210
1
2
22
10
24
102
5x102
103
1
Off
210
211
212
213
214
215
216
103
105
2x105
2x103 5x103
104
2x104 5x104
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
213
Real-Time Counter (S08RTCV1)
13.3.2
RTCCNT
RTC
Counter Register (RTCCNT)
is the read-only value of the current RTC count of the 8-bit counter.
7
6
5
4
R
3
2
1
0
0
0
0
0
RTCCNT
W
Reset:
0
0
0
0
Figure 13-4. RTC Counter Register (RTCCNT)
Table 13-4. RTCCNT Field Descriptions
Field
Description
7:0
RTCCNT
RTC Count. These eight read-only bits contain the current value of the 8-bit counter. Writes have no effect to this
register. Reset, writing to RTCMOD, or writing different values to RTCLKS and RTCPS clear the count to 0x00.
13.3.3
RTC
Modulo Register (RTCMOD)
7
6
5
4
3
2
1
0
0
0
0
0
R
RTCMOD
W
Reset:
0
0
0
0
Figure 13-5. RTC Modulo Register (RTCMOD)
Table 13-5. RTCMOD Field Descriptions
Field
Description
7:0
RTC Modulo. These eight read/write bits contain the modulo value used to reset the count to 0x00 upon a compare
RTCMOD match and set the RTIF status bit. A value of 0x00 sets the RTIF bit on each rising edge of the prescaler output.
Writing to RTCMOD resets the prescaler and the RTCCNT counters to 0x00. Reset sets the modulo to 0x00.
13.4
Functional Description
The RTC is composed of a main 8-bit up-counter with an 8-bit modulo register, a clock source selector,
and a prescaler block with binary-based and decimal-based selectable values. The module also contains
software selectable interrupt logic.
After any MCU reset, the counter is stopped and reset to 0x00, the modulus register is set to 0x00, and the
prescaler is off. The 1 kHz internal oscillator clock is selected as the default clock source. To start the
prescaler, write any value other than zero to the prescaler select bits (RTCPS).
Three clock sources are software selectable: the low power oscillator clock (LPO), the external clock
(ERCLK), and the internal clock (IRCLK). The RTC clock select bits (RTCLKS) select the desired clock
source. If a different value is written to RTCLKS, the prescaler and RTCCNT counters are reset to 0x00.
MC9S08JM16 Series Data Sheet, Rev. 2
214
Freescale Semiconductor
Real-Time Counter (S08RTCV1)
RTCPS and the RTCLKS[0] bit select the desired divide-by value. If a different value is written to RTCPS,
the prescaler and RTCCNT counters are reset to 0x00. Table 13-6 shows different prescaler period values.
Table 13-6. Prescaler Period
RTCPS
1 kHz Internal Clock
(RTCLKS = 00)
1 MHz External Clock 32 kHz Internal Clock 32 kHz Internal Clock
(RTCLKS = 01)
(RTCLKS = 10)
(RTCLKS = 11)
0000
Off
Off
Off
Off
0001
8 ms
1.024 ms
250 μs
32 ms
0010
32 ms
2.048 ms
1 ms
64 ms
0011
64 ms
4.096 ms
2 ms
128 ms
0100
128 ms
8.192 ms
4 ms
256 ms
0101
256 ms
16.4 ms
8 ms
512 ms
0110
512 ms
32.8 ms
16 ms
1.024 s
0111
1.024 s
65.5 ms
32 ms
2.048 s
1000
1 ms
1 ms
31.25 μs
31.25 ms
1001
2 ms
2 ms
62.5 μs
62.5 ms
1010
4 ms
5 ms
125 μs
156.25 ms
1011
10 ms
10 ms
312.5 μs
312.5 ms
1100
16 ms
20 ms
0.5 ms
0.625 s
1101
0.1 s
50 ms
3.125 ms
1.5625 s
1110
0.5 s
0.1 s
15.625 ms
3.125 s
1111
1s
0.2 s
31.25 ms
6.25 s
The RTC modulo register (RTCMOD) allows the compare value to be set to any value from 0x00 to 0xFF.
When the counter is active, the counter increments at the selected rate until the count matches the modulo
value. When these values match, the counter resets to 0x00 and continues counting. The real-time interrupt
flag (RTIF) is set when a match occurs. The flag sets on the transition from the modulo value to 0x00.
Writing to RTCMOD resets the prescaler and the RTCCNT counters to 0x00.
The RTC allows for an interrupt to be generated when RTIF is set. To enable the real-time interrupt, set
the real-time interrupt enable bit (RTIE) in RTCSC. RTIF is cleared by writing a 1 to RTIF.
13.4.1
RTC Operation Example
This section shows an example of the RTC operation as the counter reaches a matching value from the
modulo register.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
215
Real-Time Counter (S08RTCV1)
Internal 1 kHz
Clock Source
RTC Clock
(RTCPS = 0xA)
RTCCNT
0x52
0x53
0x54
0x55
0x00
0x01
RTIF
RTCMOD
0x55
Figure 13-6. RTC Counter Overflow Example
In the example of Figure 13-6, the selected clock source is the 1 kHz internal oscillator clock source. The
prescaler (RTCPS) is set to 0xA or divide-by-4. The modulo value in the RTCMOD register is set to 0x55.
When the counter, RTCCNT, reaches the modulo value of 0x55, the counter overflows to 0x00 and
continues counting. The real-time interrupt flag, RTIF, sets when the counter value changes from 0x55 to
0x00. A real-time interrupt is generated when RTIF is set, if RTIE is set.
13.5
Initialization/Application Information
This section provides example code to give some basic direction to a user on how to initialize and
configure the RTC module. The example software is implemented in C language.
The example below shows how to implement time of day with the RTC using the 1 kHz clock source to
achieve the lowest possible power consumption. Because the 1 kHz clock source is not as accurate as a
crystal, software can be added for any adjustments. For accuracy without adjustments at the expense of
additional power consumption, the external clock (ERCLK) or the internal clock (IRCLK) can be selected
with appropriate prescaler and modulo values.
/* Initialize the elapsed time counters */
Seconds = 0;
Minutes = 0;
Hours = 0;
Days=0;
/* Configure RTC to interrupt every 1 second from 1-kHz clock source */
RTCMOD.byte = 0x00;
RTCSC.byte = 0x1F;
/**********************************************************************
Function Name : RTC_ISR
Notes : Interrupt service routine for RTC module.
**********************************************************************/
#pragma TRAP_PROC
void RTC_ISR(void)
{
/* Clear the interrupt flag */
MC9S08JM16 Series Data Sheet, Rev. 2
216
Freescale Semiconductor
Real-Time Counter (S08RTCV1)
RTCSC.byte = RTCSC.byte | 0x80;
/* RTC interrupts every 1 Second */
Seconds++;
/* 60 seconds in a minute */
if (Seconds > 59){
Minutes++;
Seconds = 0;
}
/* 60 minutes in an hour */
if (Minutes > 59){
Hours++;
Minutes = 0;
}
/* 24 hours in a day */
if (Hours > 23){
Days ++;
Hours = 0;
}
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
217
Real-Time Counter (S08RTCV1)
MC9S08JM16 Series Data Sheet, Rev. 2
218
Freescale Semiconductor
Chapter 14
Serial Communications Interface (S08SCIV4)
14.1
Introduction
The MC9S08JM16 series include 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.
NOTE
MC9S08JM16 series devices operate at a higher voltage range (2.7 V to
5.5 V) and do not include stop1 mode. Therefore, please disregard
references to stop1.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
219
Chapter 14 Serial Communications Interface (S08SCIV4)
IRQ/TPMCLK
USB SIE
CPU
HCS08 SYSTEM CONTROL
RESETS AND INTERRUPTS
MODES OF OPERATION
POWER MANAGEMENT
FULL SPEED
USB
USB ENDPOINT TRANSCEIVER
RAM
8-/16-BIT
SERIAL PERIPHERAL
INTERFACE MODULE (SPI2)
SERIAL COMMUNICATIONS
INTERFACE MODULE (SCI2)
COP
IRQ
LVD
IIC MODULE (IIC)
VDDAD
USER FLASH (IN BYTES)
MC9S08JM16 = 16,384
MC9S08JM8 = 8,192
SS2
SPSCK2
MOSI2
MISO2
RxD2
TxD2
SDA
SCL
6
ANALOG COMPARATOR
(ACMP)
ACMP+
8-/16-BIT
SERIAL PERIPHERAL
INTERFACE MODULE (SPI1)
SPSCK1
ACMPO
VDD
VSS
VUSB33
SERIAL COMMUNICATIONS
SYSTEM
VOLTAGE
REGULATOR
INTERFACE MODULE (SCI1)
2-CHANNEL TIMER/PWM
MODULE (TPM2)
REAL-TIME COUNTER
(RTC)
7-BIT KEYBOARD
INTERRUPT MODULE (KBI)
PTE4/MISO1
TPMCLK
TPM1CH1
2
KBIPx
EXTAL
XTAL
PTE3/TPM1CH1
PTE2/TPM1CH0
PTE1/RxD1
PTE0/TxD1
TPMCLK
TPM2CH1
TPM2CH0
KBIPx
USB 3.3 V VOLTAGE REGULATOR
PTE5/MOSI1
MISO1
PORT E
LOW-POWER OSCILLATOR
PTE6/SPSCK1
MOSI1
TPM1CH0
TPM1CHx
RxD1
TxD1
PTD2/KBIP2/ACMPO
PTE7/SS1
PORT F
VSSOSC
MODULE (TPM1)
PTC5/RxD2
PTC4
PTC3/TxD2
PTC2
PTD1/ADP9/ACMP–
PTD0/ADP8/ACMP+
3
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 must not be driven above VDD.
4. Pin contains integrated pullup device.
5. When pin functions as KBI (KBIPEn = 1) and associated pin is configured to enable the
pullup device, KBEDGn can be used to reconfigure the pullup as a pulldown device.
PTF6
PTF5/TPM2CH1
PTF4/TPM2CH0
PTF1/TPM1CH3
PTF0/TPM1CH2
4
PTG5/EXTAL
PORT G
4-CHANNEL TIMER/PWM
PTB5/KBIP5/ADP5
PTB4/KBIP4/ADP4
PTB3/SS2/ADP3
PTB2/SPSCK2/ADP2
PTB1/MOSI2/ADP1
PTB0/MISO2/ADP0
PTD7
ACMP–
MULTI-PURPOSE CLOCK
GENERATOR (MCG)
PTA5, PTA0
2
SS1
USER RAM (IN BYTES)
1024
2
PTC1/SDA
PTC0/SCL
PORT D
8-CHANNEL, 12-BIT
ANALOG-TO-DIGITAL
CONVERTER (ADC)
VSSAD
VREFL
VREFH
PORT B
BDC
PORT C
RESET
PORT A
HCS08 CORE
BKGD/MS
USBDP
USBDN
ON-CHIP ICE AND
DEBUG MODULE (DBG)
PTG4/XTAL
PTG3/KBIP7
PTG2/KBIP6
PTG1/KBIP1
PTG0/KBIP0
Figure 14-1. MC9S08JM16 Series Block Diagram Highlighting the SCI Blocks and Pins
MC9S08JM16 Series Data Sheet, Rev. 2
220
Freescale Semiconductor
Serial Communications Interface (S08SCIV4)
14.1.1
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
— Active edge on receive pin
— Break detect supporting LIN
• 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 generation / 11-bit break character detection
• Selectable transmitter output polarity
14.1.2
Modes of Operation
See Section 14.3, “Functional Description,” For details concerning SCI operation in these modes:
• 8- and 9-bit data modes
• Stop mode operation
• Loop mode
• Single-wire mode
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
221
Serial Communications Interface (S08SCIV4)
14.1.3
Block Diagram
Figure 14-2 shows the transmitter portion of the SCI.
INTERNAL BUS
(WRITE-ONLY)
LOOPS
SCID – Tx BUFFER
RSRC
STOP
M
START
11-BIT TRANSMIT SHIFT REGISTER
8
7
6
5
4
3
2
1
0
TO RECEIVE
DATA IN
TO TxD PIN
L
LSB
H
1 × BAUD
RATE CLOCK
LOOP
CONTROL
SHIFT DIRECTION
PT
BREAK (ALL 0s)
PARITY
GENERATION
PREAMBLE (ALL 1s)
PE
SHIFT ENABLE
T8
LOAD FROM SCIxD
TXINV
SCI CONTROLS TxD
TE
SBK
TRANSMIT CONTROL
TXDIR
TxD DIRECTION
TO TxD
PIN LOGIC
BRK13
TDRE
TIE
TC
Tx INTERRUPT
REQUEST
TCIE
Figure 14-2. SCI Transmitter Block Diagram
MC9S08JM16 Series Data Sheet, Rev. 2
222
Freescale Semiconductor
Serial Communications Interface (S08SCIV4)
Figure 14-3 shows the receiver portion of the SCI.
INTERNAL BUS
(READ-ONLY)
16 × BAUD
RATE CLOCK
DIVIDE
BY 16
SCID – Rx BUFFER
LBKDE
H
DATA RECOVERY
WAKE
ILT
8
7
6
5
4
3
2
1
START
FROM RxD PIN
RXINV
11-BIT RECEIVE SHIFT REGISTER
LSB
RSRC
M
MSB
SINGLE-WIRE
LOOP CONTROL
ALL 1s
LOOPS
STOP
FROM
TRANSMITTER
0
L
SHIFT DIRECTION
WAKEUP
LOGIC
RWU
RWUID
ACTIVE EDGE
DETECT
RDRF
RIE
IDLE
ILIE
LBKDIF
Rx INTERRUPT
REQUEST
LBKDIE
RXEDGIF
RXEDGIE
OR
ORIE
FE
FEIE
NF
ERROR INTERRUPT
REQUEST
NEIE
PE
PT
PARITY
CHECKING
PF
PEIE
Figure 14-3. SCI Receiver Block Diagram
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
223
Serial Communications Interface (S08SCIV4)
14.2
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.
14.2.1
SCI Baud Rate Registers (SCIxBDH, SCIxBDL)
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).
7
6
5
LBKDIE
RXEDGIE
0
0
R
4
3
2
1
0
SBR12
SBR11
SBR10
SBR9
SBR8
0
0
0
0
0
0
W
Reset
0
= Unimplemented or Reserved
Figure 14-4. SCI Baud Rate Register (SCIxBDH)
Table 14-1. SCIxBDH Field Descriptions
Field
7
LBKDIE
Description
LIN Break Detect Interrupt Enable (for LBKDIF)
0 Hardware interrupts from LBKDIF disabled (use polling).
1 Hardware interrupt requested when LBKDIF flag is 1.
6
RXEDGIE
RxD Input Active Edge Interrupt Enable (for RXEDGIF)
0 Hardware interrupts from RXEDGIF disabled (use polling).
1 Hardware interrupt requested when RXEDGIF flag is 1.
4:0
SBR[12:8]
Baud Rate Modulo Divisor — The 13 bits in SBR[12:0] 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 14-2.
MC9S08JM16 Series Data Sheet, Rev. 2
224
Freescale Semiconductor
Serial Communications Interface (S08SCIV4)
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 14-5. SCI Baud Rate Register (SCIxBDL)
Table 14-2. SCIxBDL Field Descriptions
Field
7:0
SBR[7:0]
14.2.2
Description
Baud Rate Modulo Divisor — These 13 bits in SBR[12:0] 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 14-1.
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 14-6. SCI Control Register 1 (SCIxC1)
Table 14-3. SCIxC1 Field Descriptions
Field
Description
7
LOOPS
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.
6
SCISWAI
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.
5
RSRC
4
M
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.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
225
Serial Communications Interface (S08SCIV4)
Table 14-3. SCIxC1 Field Descriptions (continued)
Field
3
WAKE
Description
Receiver Wakeup Method Select — Refer to Section 14.3.3.2, “Receiver Wakeup Operation” for more
information.
0 Idle-line wakeup.
1 Address-mark wakeup.
2
ILT
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 logic high level needed by the idle line detection logic. Refer to
Section 14.3.3.2.1, “Idle-Line Wakeup” for more information.
0 Idle character bit count starts after start bit.
1 Idle character bit count starts after stop bit.
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.
14.2.3
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 14-7. SCI Control Register 2 (SCIxC2)
Table 14-4. SCIxC2 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 interrupts from TC disabled (use polling).
1 Hardware interrupt requested when TC flag is 1.
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.
MC9S08JM16 Series Data Sheet, Rev. 2
226
Freescale Semiconductor
Serial Communications Interface (S08SCIV4)
Table 14-4. SCIxC2 Field Descriptions (continued)
Field
Description
3
TE
Transmitter Enable
0 Transmitter off.
1 Transmitter on.
TE must be 1 in order to use the SCI transmitter. When TE = 1, the SCI forces the TxD pin to act as an output
for the SCI system.
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 14.3.2.1, “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.
2
RE
Receiver Enable — When the SCI receiver is off, the RxD pin reverts to being a general-purpose port I/O pin. If
LOOPS = 1 the RxD pin reverts to being a general-purpose I/O pin even if RE = 1.
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 14.3.3.2, “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 (13 or 14 if BRK13 = 1) 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 14.3.2.1, “Send Break and
Queued Idle” for more details.
0 Normal transmitter operation.
1 Queue break character(s) to be sent.
14.2.4
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 14-8. SCI Status Register 1 (SCIxS1)
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
227
Serial Communications Interface (S08SCIV4)
Table 14-5. SCIxS1 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
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.
MC9S08JM16 Series Data Sheet, Rev. 2
228
Freescale Semiconductor
Serial Communications Interface (S08SCIV4)
Table 14-5. SCIxS1 Field Descriptions (continued)
Field
Description
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.
14.2.5
SCI Status Register 2 (SCIxS2)
This register has one read-only status flag.
7
6
LBKDIF
RXEDGIF
0
0
R
5
4
3
2
1
RXINV
RWUID
BRK13
LBKDE
0
0
0
0
0
0
RAF
W
Reset
0
0
= Unimplemented or Reserved
Figure 14-9. SCI Status Register 2 (SCIxS2)
Table 14-6. SCIxS2 Field Descriptions
Field
Description
7
LBKDIF
LIN Break Detect Interrupt Flag — LBKDIF is set when the LIN break detect circuitry is enabled and a LIN break
character is detected. LBKDIF is cleared by writing a “1” to it.
0 No LIN break character has been detected.
1 LIN break character has been detected.
6
RXEDGIF
RxD Pin Active Edge Interrupt Flag — RXEDGIF is set when an active edge (falling if RXINV = 0, rising if
RXINV=1) on the RxD pin occurs. RXEDGIF is cleared by writing a “1” to it.
0 No active edge on the receive pin has occurred.
1 An active edge on the receive pin has occurred.
4
RXINV1
Receive Data Inversion — Setting this bit reverses the polarity of the received data input.
0 Receive data not inverted
1 Receive data inverted
3
RWUID
Receive Wake Up Idle Detect— RWUID controls whether the idle character that wakes up the receiver sets the
IDLE bit.
0 During receive standby state (RWU = 1), the IDLE bit does not get set upon detection of an idle character.
1 During receive standby state (RWU = 1), the IDLE bit gets set upon detection of an idle character.
2
BRK13
Break Character Generation Length — BRK13 is used to select a longer transmitted break character length.
Detection of a framing error is not affected by the state of this bit.
0 Break character is transmitted with length of 10 bit times (11 if M = 1)
1 Break character is transmitted with length of 13 bit times (14 if M = 1)
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
229
Serial Communications Interface (S08SCIV4)
Table 14-6. SCIxS2 Field Descriptions (continued)
1
Field
Description
1
LBKDE
LIN Break Detection Enable— LBKDE is used to select a longer break character detection length. While LBKDE
is set, framing error (FE) and receive data register full (RDRF) flags are prevented from setting.
0 Break character is detected at length of 10 bit times (11 if M = 1).
1 Break character is detected at length of 11 bit times (12 if M = 1).
0
RAF
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).
Setting RXINV inverts the RxD input for all cases: data bits, start and stop bits, break, and idle.
When using an internal oscillator in a LIN system, it is necessary to raise the break detection threshold by
one bit time. Under the worst case timing conditions allowed in LIN, it is possible that a 0x00 data
character can appear to be 10.26 bit times long at a slave which is running 14% faster than the master. This
would trigger normal break detection circuitry which is designed to detect a 10 bit break symbol. When
the LBKDE bit is set, framing errors are inhibited and the break detection threshold changes from 10 bits
to 11 bits, preventing false detection of a 0x00 data character as a LIN break symbol.
14.2.6
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 14-10. SCI Control Register 3 (SCIxC3)
Table 14-7. SCIxC3 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 must 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.
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.
MC9S08JM16 Series Data Sheet, Rev. 2
230
Freescale Semiconductor
Serial Communications Interface (S08SCIV4)
Table 14-7. SCIxC3 Field Descriptions (continued)
Field
4
TXINV1
1
Description
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.
14.2.7
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 14-11. SCI Data Register (SCIxD)
14.3
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.
14.3.1
Baud Rate Generation
As shown in Figure 14-12, the clock source for the SCI baud rate generator is the bus-rate clock.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
231
Serial Communications Interface (S08SCIV4)
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 14-12. 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.
14.3.2
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 14-2.
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,
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 TxD pin, the
transmitter sets the transmit complete flag and enters an idle mode, with TxD high, waiting for more
characters to transmit.
MC9S08JM16 Series Data Sheet, Rev. 2
232
Freescale Semiconductor
Serial Communications Interface (S08SCIV4)
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.
14.3.2.1
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 TxD 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 TxD is an output driving a logic 1. This ensures that the TxD 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 14-8. Break Character Length
14.3.3
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
Receiver Functional Description
In this section, the receiver block diagram (Figure 14-3) 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 input is inverted by setting RXINV = 1. 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 14.3.5.1, “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)
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
233
Serial Communications Interface (S08SCIV4)
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 14.3.4,
“Interrupts and Status Flags,” for more details about flag clearing.
14.3.3.1
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 RxD 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.
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.
14.3.3.2
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 bit is set,
the status flags associated with the receiver (with the exception of the idle bit, IDLE, when RWUID bit is
set) are inhibited from setting, thus eliminating the software overhead for handling the unimportant
MC9S08JM16 Series Data Sheet, Rev. 2
234
Freescale Semiconductor
Serial Communications Interface (S08SCIV4)
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.
14.3.3.2.1
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 RWU is one and RWUID is zero, the idle condition that wakes up the receiver does not set the IDLE
flag. The receiver wakes up and waits for the first data character of the next message which will set the
RDRF flag and generate an interrupt if enabled. When RWUID is one, any idle condition sets the IDLE
flag and generates an interrupt if enabled, regardless of whether RWU is zero or one.
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.
14.3.3.2.2
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 RWU bit before the stop bit is
received and sets the RDRF flag. In this case the character with the MSB set is received even though the
receiver was sleeping during most of this character time.
14.3.4
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, IDLE, RXEDGIF and LBKDIF events,
and a third vector is used for OR, NF, FE, and PF error conditions. Each of these ten interrupt sources can
be separately 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 TxD at the inactive level. 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.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
235
Serial Communications Interface (S08SCIV4)
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 RxD 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 the data along with any associated NF, FE, or PF
condition is lost.
At any time, an active edge on the RxD serial data input pin causes the RXEDGIF flag to set. The
RXEDGIF flag is cleared by writing a “1” to it. This function does depend on the receiver being enabled
(RE = 1).
14.3.5
Additional SCI Functions
The following sections describe additional SCI functions.
14.3.5.1
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.
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.
MC9S08JM16 Series Data Sheet, Rev. 2
236
Freescale Semiconductor
Serial Communications Interface (S08SCIV4)
14.3.5.2
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.
The receive input active edge detect circuit is still active in stop3 mode, but not in stop2. An active edge
on the receive input brings the CPU out of stop3 mode if the interrupt is not masked (RXEDGIE = 1).
Note, because the clocks are halted, the SCI module will resume operation upon exit from stop (only in
stop3 mode). Software must ensure stop mode is not entered while there is a character being transmitted
out of or received into the SCI module.
14.3.5.3
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 RxD pin is not used by the SCI, so it reverts to a
general-purpose port I/O pin.
14.3.5.4
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 TxD pin. The RxD 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 TxD pin. When
TXDIR = 0, the TxD pin is an input to the SCI receiver and the transmitter is temporarily disconnected
from the TxD pin so an external device can send serial data to the receiver. When TXDIR = 1, the TxD 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.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
237
Serial Communications Interface (S08SCIV4)
MC9S08JM16 Series Data Sheet, Rev. 2
238
Freescale Semiconductor
Chapter 15
16-Bit Serial Peripheral Interface (S08SPI16V1)
15.1
Introduction
The 8- or 16-bit selectable 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 in master mode and up to the bus clock
divided by four in slave mode. Software can poll the status flags, or SPI operation can be interrupt driven.
The SPI also supports a data length of 8 or 16 bits and includes a hardware match feature for the receive
data buffer.
The MC9S08JM16 series have two serial peripheral interface modules (SPI1 and SPI2). The four pins
associated with SPI functionality are shared with PTB[3:0] and PTE[7:4]. See Appendix A, “Electrical
Characteristics,” for SPI electrical parametric information.
15.1.1
SPI Port Configuration Information
By default, the input filters on the SPI port pins will be enabled (SPIxFE=1), which restricts the SPI data
rate to 6 MHz, but protects the SPI from noise during data transfers.To configure the SPI at a baud rate of
6 MHz or greater, the input filters on the SPI port pins must be disabled by clearing the SPIxFE in SOPT2.
and also enable the high output drive strength selection on the affected SPI port pins.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
239
Chapter 15 16-Bit Serial Peripheral Interface (S08SPI16V1)
USBDP
USBDN
HCS08 CORE
PORT A
ON-CHIP ICE AND
DEBUG MODULE (DBG)
USB SIE
RESET
IRQ/TPMCLK
CPU
HCS08 SYSTEM CONTROL
RESETS AND INTERRUPTS
MODES OF OPERATION
POWER MANAGEMENT
COP
IRQ
8-/16-BIT SERIAL PERIPHERAL
INTERFACE MODULE (SPI2)
SERIAL COMMUNICATIONS
VDDAD
IIC MODULE (IIC)
SDA
SCL
6
ACMPO
VDD
VSS
VUSB33
LOW-POWER OSCILLATOR
SYSTEM
VOLTAGE
REGULATOR
PTE5/MOSI1
SERIAL COMMUNICATIONS
INTERFACE MODULE (SCI1)
2-CHANNEL TIMER/PWM
MODULE (TPM2)
TPM1CH0
TPM1CHx
2
PTE3/TPM1CH1
PTE2/TPM1CH0
RxD1
TxD1
PTE1/RxD1
PTE0/TxD1
TPMCLK
TPM2CH1
TPM2CH0
PTF6
PTF5/TPM2CH1
PTF4/TPM2CH0
KBIPx
7-BIT KEYBOARD
INTERRUPT MODULE (KBI)
PTE4/MISO1
TPMCLK
TPM1CH1
PORT E
MODULE (TPM1)
USB 3.3 V VOLTAGE REGULATOR
REAL-TIME COUNTER
(RTC)
PTE6/SPSCK1
MOSI1
KBIPx
EXTAL
XTAL
PORT F
VSSOSC
PTE7/SS1
SPSCK1
MISO1
4-CHANNEL TIMER/PWM
PTD2/KBIP2/ACMPO
PTD1/ADP9/ACMP–
PTD0/ADP8/ACMP+
ACMP+
3
PTF1/TPM1CH3
PTF0/TPM1CH2
4
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 must not be driven above VDD.
4. Pin contains integrated pullup device.
5. When pin functions as KBI (KBIPEn = 1) and associated pin is configured to enable the
pullup device, KBEDGn can be used to reconfigure the pullup as a pulldown device.
PTG5/EXTAL
PORT G
MULTI-PURPOSE CLOCK
GENERATOR (MCG)
8-/16-BIT SERIAL PERIPHERAL
INTERFACE MODULE (SPI16)
PTC5/RxD2
PTC4
PTC3/TxD2
PTC2
PTD7
SS1
USER RAM (IN BYTES)
MC9S08JM60 = 4096
MC9S08JM32 = 2048
PTB5/KBIP5/ADP5
PTB4/KBIP4/ADP4
PTB3/SS2/ADP3
PTB2/SPSCK2/ADP2
PTB1/MOSI2/ADP1
PTB0/MISO2/ADP0
2
ACMP–
ANALOG COMPARATOR
(ACMP)
PTA5, PTA0
PTC1/SDA
PTC0/SCL
PORT D
USER Flash (IN BYTES)
MC9S08JM60 = 60,912
MC9S08JM32 = 32,768
RxD2
TxD2
12-CHANNEL, 12-BIT
ANALOG-TO-DIGITAL
CONVERTER (ADC)
VSSAD
VREFL
VREFH
SS2
SPSCK2
MOSI2
MISO2
INTERFACE MODULE (SCI2)
LVD
PORT B
BDC
PORT C
BKGD/MS
FULL SPEED
USB
USB ENDPOINT TRANSCEIVER
RAM
2
PTG4/XTAL
PTG3/KBIP7
PTG2/KBIP6
PTG1/KBIP1
PTG0/KBIP0
Figure 15-1. MC9S08JM16 Series Block Diagram Highlighting the SPI Blocks and Pins
MC9S08JM16 Series Data Sheet, Rev. 2
240
Freescale Semiconductor
Serial Peripheral Interface (S08SPI16V1)
Module Initialization (Slave):
Write:
SPIxC1
to configure
interrupts, set primary SPI options, slave mode select, and
system enable.
Write:
SPIxC2
to configure
optional SPI features, hardware match interrupt enable,
and 8- or 16-bit data transmission length
Write:
SPIxMH:SPIxML
to set
hardware compare value that triggers SPMF (optional)
when value in receive data buffer equals this value.
Module Initialization (Master):
Write:
SPIxC1
to configure
interrupts, set primary SPI options, master mode select,
and system enable.
Write:
SPIxC2
to configure
optional SPI features, hardware match interrupt enable,
and 8- or 16-bit data transmission length
Write:
SPIxBR
to set
baud rate
Write:
SPIxMH:SPIxML
to set
hardware compare value that triggers SPMF (optional)
when value in receive data buffer equals this value.
Module Use:
After SPI master initiates transfer by checking that SPTEF = 1 and then writing data to SPIDH/L:
Wait for SPRF, then read from SPIDH/L
Wait for SPTEF, then write to SPIDH/L
Data transmissions can be 8- or 16-bits long, and 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. Also, some applications may utilize the receive data
buffer hardware match feature to trigger specific actions, such as when command data can be sent through the SPI or to
indicate the end of an SPI transmission.
SPIxC1
SPIE
SPE
SPTIE
MSTR
CPOL
CPHA
SSOE
LSBFE
Module/interrupt enables and configuration
SPIxC2
SPMIE
MODFEN
SPIMODE
BIDIROE
SPISWAI
SPC0
SPR2
SPR1
SPR0
Additional configuration options.
SPIxBR
SPPR2
SPPR1
SPPR0
Baud rate = (BUSCLK/SPPR[2:0])/SPR2[2:0]
SPIxDH
Bit 15
Bit 14
Bit 13
Bit 12
Bit 11
Bit 10
Bit 9
Bit 8
SPIxDL
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
SPIxMH
Bit 15
Bit 14
Bit 13
Bit 12
Bit 11
Bit 10
Bit 9
Bit 8
SPIxML
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Hardware Match Value
SPIxS
SPRF
SPMF
SPTEF
MODF
Figure 15-2. SPI Module Quick Start
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
241
Serial Peripheral Interface (S08SPI16V1)
15.1.2
Features
The SPI includes these distinctive features:
• Master mode or slave mode operation
• Full-duplex or single-wire bidirectional mode
• Programmable transmit bit rate
• Double-buffered transmit and receive data register
• Serial clock phase and polarity options
• Slave select output
• Mode fault error flag with CPU interrupt capability
• Control of SPI operation during wait mode
• Selectable MSB-first or LSB-first shifting
• Programmable 8- or 16-bit data transmission length
• Receive data buffer hardware match feature
15.1.3
Modes of Operation
The SPI functions in three modes, run, wait, and stop.
• Run Mode
This is the basic mode of operation.
• Wait Mode
SPI operation in wait mode is a configurable low power mode, controlled by the SPISWAI bit
located in the SPIxC2 register. In wait mode, if the SPISWAI bit is clear, the SPI operates like in
Run Mode. If the SPISWAI bit is set, the SPI goes into a power conservative state, with the SPI
clock generation turned off. If the SPI is configured as a master, any transmission in progress stops,
but is resumed after CPU goes into Run Mode. If the SPI is configured as a slave, reception and
transmission of a byte continues, so that the slave stays synchronized to the master.
• Stop Mode
The SPI is inactive in stop3 mode for reduced power consumption. If the SPI is configured as a
master, any transmission in progress stops, but is resumed after the CPU goes into Run Mode. If
the SPI is configured as a slave, reception and transmission of a data continues, so that the slave
stays synchronized to the master.
The SPI is completely disabled in all other stop modes. When the CPU wakes from these stop modes, all
SPI register content will be reset.
This is a high level description only, detailed descriptions of operating modes are contained in section
Section 15.4.9, “Low Power Mode Options.”
15.1.4
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.
MC9S08JM16 Series Data Sheet, Rev. 2
242
Freescale Semiconductor
Serial Peripheral Interface (S08SPI16V1)
15.1.4.1
SPI System Block Diagram
Figure 15-3 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
8 OR 16 BITS
SPI SHIFTER
MISO
SPSCK
CLOCK
GENERATOR
SS
MISO
8 OR 16 BITS
SPSCK
SS
Figure 15-3. SPI System Connections
15.1.4.2
SPI Module Block Diagram
Figure 15-4 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 SPIxDH:SPIxDL) and gets transferred to the
SPI shift register at the start of a data transfer. After shifting in 8 or 16 bits (as determined by SPIMODE
bit) of data, the data is transferred into the double-buffered receiver where it can be read (read from
SPIxDH:SPIxDL). 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.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
243
Serial Peripheral Interface (S08SPI16V1)
PIN CONTROL
M
SPE
MOSI
(MOMI)
S
Tx BUFFER (WRITE SPIxDH:SPIxDL)
ENABLE
SPI SYSTEM
M
SHIFT
OUT
SPIMODE
8 OR 16
BIT MODE
SHIFT
IN
SPI SHIFT REGISTER
MISO
(SISO)
S
SPC0
Rx BUFFER (READ SPIxDH:SPIxDL)
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
16-BIT COMPARATOR
SPIxMH:SPIxML
16-BIT LATCH
SPRF
SS
SPMF
SPMIE
SPTEF
SPTIE
MODF
SPIE
SPI
INTERRUPT
REQUEST
Figure 15-4. SPI Module Block Diagram
15.2
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.
15.2.1
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.
MC9S08JM16 Series Data Sheet, Rev. 2
244
Freescale Semiconductor
Serial Peripheral Interface (S08SPI16V1)
15.2.2
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.
15.2.3
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.
15.2.4
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).
15.3
Register Definition
The SPI has eight 8-bit registers to select SPI options, control baud rate, report SPI status, hold an SPI data
match value, 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.
15.3.1
SPI Control Register 1 (SPIxC1)
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 15-5. SPI Control Register 1 (SPIxC1)
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
245
Serial Peripheral Interface (S08SPI16V1)
Table 15-1. SPIxC1 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 — This bit enables the SPI system and dedicates the SPI port pins to SPI system functions.
If SPE is cleared, SPI is disabled and forced into idle state, and all status bits in the SPIxS register are reset.
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 — This bit selects master or slave mode operation.
0 SPI module configured as a slave SPI device
1 SPI module configured as a master SPI device
3
CPOL
Clock Polarity — This bit selects an inverted or non-inverted SPI clock. To transmit data between SPI modules,
the SPI modules must have identical CPOL values.
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 15.4.5, “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 15.4.5, “SPI Clock Formats” for more details.
0 First edge on SPSCK occurs at the middle of the first cycle of a data transfer
1 First edge on SPSCK occurs at the start of the first cycle of a data transfer
1
SSOE
Slave Select Output Enable — This bit is used in combination with the mode fault enable (MODFEN) bit in
SPIxC2 and the master/slave (MSTR) control bit to determine the function of the SS pin as shown in Table 15-2.
0
LSBFE
LSB First (Shifter Direction) — This bit does not affect the position of the MSB and LSB in the data register.
Reads and writes of the data register always have the MSB in bit 7 (or bit 15 in 16-bit mode).
0 SPI serial data transfers start with most significant bit
1 SPI serial data transfers start with least significant bit
Table 15-2. SS Pin Function
15.3.2
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 (SPIxC2)
This read/write register is used to control optional features of the SPI system. Bits 6 and 5 are not
implemented and always read 0.
MC9S08JM16 Series Data Sheet, Rev. 2
246
Freescale Semiconductor
Serial Peripheral Interface (S08SPI16V1)
7
6
5
SPMIE
SPIMODE
0
0
R
4
3
MODFEN
BIDIROE
0
0
0
2
1
0
SPISWAI
SPC0
0
0
0
W
Reset
0
0
= Unimplemented or Reserved
Figure 15-6. SPI Control Register 2 (SPIxC2)
Table 15-3. SPIxC2 Register Field Descriptions
Field
7
SPMIE
Description
SPI Match Interrupt Enable — This is the interrupt enable for the SPI receive data buffer hardware match
(SPMF) function.
0 Interrupts from SPMF inhibited (use polling).
1 When SPMF = 1, requests a hardware interrupt.
6
SPIMODE
SPI 8- or 16-bit Mode — This bit allows the user to select either an 8-bit or 16-bit SPI data transmission length.
In master mode, a change of this bit will abort a transmission in progress, force the SPI system into idle state,
and reset all status bits in the SPIxS register. Refer to section Section 15.4.4, “Data Transmission Length,” for
details.
0 8-bit SPI shift register, match register, and buffers.
1 16-bit SPI shift register, match register, and buffers.
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 15-2 for 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
1
SPISWAI
SPI Stop in Wait Mode — This bit is used for power conservation while in wait.
0 SPI clocks continue to operate in wait mode
1 SPI clocks stop when the MCU enters wait mode
0
SPC0
SPI Pin Control 0 — This bit enables bidirectional pin configurations as shown in Table 15-4.
0 SPI uses separate pins for data input and data output.
1 SPI configured for single-wire bidirectional operation.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
247
Serial Peripheral Interface (S08SPI16V1)
Table 15-4. Bidirectional Pin Configurations
Pin Mode
SPC0
BIDIROE
MISO
MOSI
Master Mode of Operation
Normal
0
X
Master In
Master Out
Bidirectional
1
0
MISO not used by SPI
Master In
1
Master I/O
Slave Mode of Operation
15.3.3
Normal
0
X
Slave Out
Slave In
Bidirectional
1
0
Slave In
MOSI not used by SPI
1
Slave I/O
SPI Baud Rate Register (SPIxBR)
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 15-7. SPI Baud Rate Register (SPIxBR)
Table 15-5. SPIxBR 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 15-6. 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 15-15). See Section 15.4.6, “SPI Baud Rate Generation,”
for details.
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 15-7. The input to this divider comes from the SPI baud rate prescaler (see Figure 15-15). See
Section 15.4.6, “SPI Baud Rate Generation,” for details.
MC9S08JM16 Series Data Sheet, Rev. 2
248
Freescale Semiconductor
Serial Peripheral Interface (S08SPI16V1)
Table 15-6. 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
Table 15-7. SPI Baud Rate Divisor
15.3.4
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 (SPIxS)
This register has four read-only status bits. Bits 3 through 0 are not implemented and always read 0. Writes
have no meaning or effect.
R
7
6
5
4
3
2
1
0
SPRF
SPMF
SPTEF
MODF
0
0
0
0
0
0
1
0
0
0
0
0
W
Reset
= Unimplemented or Reserved
Figure 15-8. SPI Status Register (SPIxS)
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
249
Serial Peripheral Interface (S08SPI16V1)
Table 15-8. SPIxS 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 (SPIxDH:SPIxDL). 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.
6
SPMF
SPI Match Flag — SPMF is set after SPRF = 1 when the value in the receive data buffer matches the value in
SPIMH:SPIML. To clear the flag, read SPMF when it is set, then write a 1 to it.
0 Value in the receive data buffer does not match the value in SPIxMH:SPIxML registers.
1 Value in the receive data buffer matches the value in SPIxMH:SPIxML registers.
5
SPTEF
SPI Transmit Buffer Empty Flag — This bit is set when the transmit data buffer is empty. It is cleared by reading
SPIxS with SPTEF set, followed by writing a data value to the transmit buffer at SPIxDH:SPIxDL. SPIxS must be
read with SPTEF = 1 before writing data to SPIxDH:SPIxDL or the SPIxDH:SPIxDL write will be ignored. SPTEF
is automatically set when all data from the transmit buffer transfers into the transmit shift register. For an idle SPI,
data written to SPIxDH:SPIxDL is transferred to the shifter almost immediately so SPTEF is set within two bus
cycles allowing a second data to be queued into the transmit buffer. After completion of the transfer of the data
in the shift register, the queued data 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 (SPIxC1).
0 No mode fault error
1 Mode fault error detected
15.3.5
SPI Data Registers (SPIxDH:SPIxDL)
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 15-9. SPI Data Register High (SPIxDH)
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 15-10. SPI Data Register Low (SPIxDL)
The SPI data registers (SPIxDH:SPIxDL) are both the input and output register for SPI data. A write to
these registers writes to the transmit data buffer, allowing data to be queued and transmitted.
MC9S08JM16 Series Data Sheet, Rev. 2
250
Freescale Semiconductor
Serial Peripheral Interface (S08SPI16V1)
When the SPI is configured as a master, data queued in the transmit data buffer is transmitted immediately
after the previous transmission has completed.
The SPI transmit buffer empty flag (SPTEF) in the SPIxS register indicates when the transmit data buffer
is ready to accept new data. SPIxS must be read when SPTEF is set before writing to the SPI data registers,
or the write will be ignored.
Data may be read from SPIxDH:SPIxDL 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.
In 8-bit mode, only SPIxDL is available. Reads of SPIxDH will return all 0s. Writes to SPIxDH will be
ignored.
In 16-bit mode, reading either byte (SPIxDH or SPIxDL) latches the contents of both bytes into a buffer
where they remain latched until the other byte is read. Writing to either byte (SPIxDH or SPIxDL) latches
the value into a buffer. When both bytes have been written, they are transferred as a coherent 16-bit value
into the transmit data buffer.
15.3.6
SPI Match Registers (SPIxMH:SPIxML)
These read/write registers contain the hardware compare value, which sets the SPI match flag (SPMF)
when the value received in the SPI receive data buffer equals the value in the SPIxMH:SPIxML registers.
In 8-bit mode, only SPIxML is available. Reads of SPIxMH will return all 0s. Writes to SPIxMH will be
ignored.
In 16-bit mode, reading either byte (SPIxMH or SPIxML) latches the contents of both bytes into a buffer
where they remain latched until the other byte is read. Writing to either byte (SPIxMH or SPIxML) latches
the value into a buffer. When both bytes have been written, they are transferred as a coherent value into
the SPI match registers.
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 15-11. SPI Match Register High (SPIxMH)
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 15-12. SPI Match Register Low (SPIxML)
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
251
Serial Peripheral Interface (S08SPI16V1)
15.4
15.4.1
Functional Description
General
The SPI system is enabled by setting the SPI enable (SPE) bit in SPI Control Register 1. While the SPE
bit is set, the four associated SPI port pins are dedicated to the SPI function as:
• Slave select (SS)
• Serial clock (SPSCK)
• Master out/slave in (MOSI)
• Master in/slave out (MISO)
An SPI transfer is initiated in the master SPI device by reading the SPI status register (SPIxS) when
SPTEF = 1 and then writing data to the transmit data buffer (write to SPIxDH:SPIxDL). When a transfer
is complete, received data is moved into the receive data buffer. The SPIxDH:SPIxDL registers act as the
SPI receive data buffer for reads and as the SPI transmit data buffer for writes.
The clock phase control bit (CPHA) and a clock polarity control bit (CPOL) in the SPI Control Register 1
(SPIxC1) select one of four possible clock formats to be used by the SPI system. The CPOL bit simply
selects a non-inverted or inverted clock. The CPHA bit is used to accommodate two fundamentally
different protocols by sampling data on odd numbered SPSCK edges or on even numbered SPSCK edges.
The SPI can be configured to operate as a master or as a slave. When the MSTR bit in SPI control register
1 is set, master mode is selected, when the MSTR bit is clear, slave mode is selected.
15.4.2
Master Mode
The SPI operates in master mode when the MSTR bit is set. Only a master SPI module can initiate
transmissions. A transmission begins by reading the SPIxS register while SPTEF = 1 and writing to the
master SPI data registers. If the shift register is empty, the byte immediately transfers to the shift register.
The data begins shifting out on the MOSI pin under the control of the serial clock.
• SPSCK
The SPR2, SPR1, and SPR0 baud rate selection bits in conjunction with the SPPR2, SPPR1, and SPPR0
baud rate preselection bits in the SPI Baud Rate register control the baud rate generator and determine the
speed of the transmission. The SPSCK pin is the SPI clock output. Through the SPSCK pin, the baud rate
generator of the master controls the shift register of the slave peripheral.
• MOSI, MISO pin
In master mode, the function of the serial data output pin (MOSI) and the serial data input pin (MISO) is
determined by the SPC0 and BIDIROE control bits.
• SS pin
If MODFEN and SSOE bit are set, the SS pin is configured as slave select output. The SS output becomes
low during each transmission and is high when the SPI is in idle state.
If MODFEN is set and SSOE is cleared, the SS pin is configured as input for detecting mode fault error.
If the SS input becomes low this indicates a mode fault error where another master tries to drive the MOSI
MC9S08JM16 Series Data Sheet, Rev. 2
252
Freescale Semiconductor
Serial Peripheral Interface (S08SPI16V1)
and SPSCK lines. In this case, the SPI immediately switches to slave mode, by clearing the MSTR bit and
also disables the slave output buffer MISO (or SISO in bidirectional mode). So the result is that all outputs
are disabled and SPSCK, MOSI and MISO are inputs. If a transmission is in progress when the mode fault
occurs, the transmission is aborted and the SPI is forced into idle state.
This mode fault error also sets the mode fault (MODF) flag in the SPI Status Register (SPIxS). If the SPI
interrupt enable bit (SPIE) is set when the MODF flag gets set, then an SPI interrupt sequence is also
requested.
When a write to the SPI Data Register in the master occurs, there is a half SPSCK-cycle delay. After the
delay, SPSCK is started within the master. The rest of the transfer operation differs slightly, depending on
the clock format specified by the SPI clock phase bit, CPHA, in SPI Control Register 1 (see Section 15.4.5,
“SPI Clock Formats.”)
NOTE
A change of the bits CPOL, CPHA, SSOE, LSBFE, MODFEN, SPC0,
BIDIROE with SPC0 set, SPIMODE, SPPR2–SPPR0 and SPR2–SPR0 in
master mode will abort a transmission in progress and force the SPI into idle
state. The remote slave cannot detect this, therefore the master has to ensure
that the remote slave is set back to idle state.
15.4.3
Slave Mode
The SPI operates in slave mode when the MSTR bit in SPI Control Register1 is clear.
• SPSCK
In slave mode, SPSCK is the SPI clock input from the master.
• MISO, MOSI pin
In slave mode, the function of the serial data output pin (MISO) and serial data input pin (MOSI) is
determined by the SPC0 bit and BIDIROE bit in SPI Control Register 2.
• SS pin
The SS pin is the slave select input. Before a data transmission occurs, the SS pin of the slave SPI must
be low. SS must remain low until the transmission is complete. If SS goes high, the SPI is forced into idle
state.
The SS input also controls the serial data output pin, if SS is high (not selected), the serial data output pin
is high impedance, and, if SS is low the first bit in the SPI Data Register is driven out of the serial data
output pin. Also, if the slave is not selected (SS is high), then the SPSCK input is ignored and no internal
shifting of the SPI shift register takes place.
Although the SPI is capable of duplex operation, some SPI peripherals are capable of only receiving SPI
data in a slave mode. For these simpler devices, there is no serial data out pin.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
253
Serial Peripheral Interface (S08SPI16V1)
NOTE
When peripherals with duplex capability are used, take care not to
simultaneously enable two receivers whose serial outputs drive the same
system slave’s serial data output line.
As long as no more than one slave device drives the system slave’s serial data output line, it is possible for
several slaves to receive the same transmission from a master, although the master would not receive return
information from all of the receiving slaves.
If the CPHA bit in SPI Control Register 1 is clear, odd numbered edges on the SPSCK input cause the data
at the serial data input pin to be latched. Even numbered edges cause the value previously latched from the
serial data input pin to shift into the LSB or MSB of the SPI shift register, depending on the LSBFE bit.
If the CPHA bit is set, even numbered edges on the SPSCK input cause the data at the serial data input pin
to be latched. Odd numbered edges cause the value previously latched from the serial data input pin to shift
into the LSB or MSB of the SPI shift register, depending on the LSBFE bit.
When CPHA is set, the first edge is used to get the first data bit onto the serial data output pin. When CPHA
is clear and the SS input is low (slave selected), the first bit of the SPI data is driven out of the serial data
output pin. After the eighth (SPIMODE = 0) or sixteenth (SPIMODE = 1) shift, the transfer is considered
complete and the received data is transferred into the SPI data registers. To indicate transfer is complete,
the SPRF flag in the SPI Status Register is set.
NOTE
A change of the bits CPOL, CPHA, SSOE, LSBFE, MODFEN, SPC0 and
BIDIROE with SPC0 set and SPIMODE in slave mode will corrupt a
transmission in progress and has to be avoided.
15.4.4
Data Transmission Length
The SPI can support data lengths of 8 or 16 bits. The length can be configured with the SPIMODE bit in
the SPIxC2 register.
In 8-bit mode (SPIMODE = 0), the SPI Data Register is comprised of one byte: SPIxDL. The SPI Match
Register is also comprised of only one byte: SPIxML. Reads of SPIxDH and SPIxMH will return zero.
Writes to SPIxDH and SPIxMH will be ignored.
In 16-bit mode (SPIMODE = 1), the SPI Data Register is comprised of two bytes: SPIxDH and SPIxDL.
Reading either byte (SPIxDH or SPIxDL) latches the contents of both bytes into a buffer where they
remain latched until the other byte is read. Writing to either byte (SPIxDH or SPIxDL) latches the value
into a buffer. When both bytes have been written, they are transferred as a coherent 16-bit value into the
transmit data buffer.
In 16-bit mode, the SPI Match Register is also comprised of two bytes: SPIxMH and SPIxML. Reading
either byte (SPIxMH or SPIxML) latches the contents of both bytes into a buffer where they remain latched
until the other byte is read. Writing to either byte (SPIxMH or SPIxML) latches the value into a buffer.
When both bytes have been written, they are transferred as a coherent 16-bit value into the transmit data
buffer.
MC9S08JM16 Series Data Sheet, Rev. 2
254
Freescale Semiconductor
Serial Peripheral Interface (S08SPI16V1)
Any switching between 8- and 16-bit data transmission length (controlled by SPIMODE bit) in master
mode will abort a transmission in progress, force the SPI system into idle state, and reset all status bits in
the SPIxS register. To initiate a transfer after writing to SPIMODE, the SPIxS register must be read with
SPTEF = 1, and data must be written to SPIxDH:SPIxDL in 16-bit mode (SPIMODE = 1) or SPIxDL in
8-bit mode (SPIMODE = 0).
In slave mode, user software must write to SPIMODE only once to prevent corrupting a transmission in
progress.
NOTE
Data can be lost if the data length is not the same for both master and slave
devices.
15.4.5
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 15-13 shows the clock formats when SPIMODE = 0 (8-bit mode) and 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.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
255
Serial Peripheral Interface (S08SPI16V1)
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 15-13. 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 CPHA = 1, the slave’s SS input is not required to go to its inactive
high level between transfers.
Figure 15-14 shows the clock formats when SPIMODE = 0 and 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
MC9S08JM16 Series Data Sheet, Rev. 2
256
Freescale Semiconductor
Serial Peripheral Interface (S08SPI16V1)
SPSCK cycle after 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 15-14. 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.
15.4.6
SPI Baud Rate Generation
As shown in Figure 15-15, 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.
The baud rate generator is activated only when the SPI is in the master mode and a serial transfer is taking
place. In the other cases, the divider is disabled to decrease IDD current.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
257
Serial Peripheral Interface (S08SPI16V1)
The baud rate divisor equation is as follows:
BaudRateDivisor = ( SPPR + 1 ) • 2
( SPR + 1 )
The baud rate can be calculated with the following equation:
Baud Rate = BusClock ⁄ BaudRateDivisor
BUS CLOCK
PRESCALER
BAUD 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 15-15. SPI Baud Rate Generation
15.4.7
15.4.7.1
Special Features
SS Output
The SS output feature automatically drives the SS pin low during transmission to select external devices
and drives it high during idle to deselect external devices. When SS output is selected, the SS output pin
is connected to the SS input pin of the external device.
The SS output is available only in master mode during normal SPI operation by asserting the SSOE and
MODFEN bits as shown in Table 15-2.
The mode fault feature is disabled while SS output is enabled.
NOTE
Care must be taken when using the SS output feature in a multi-master
system since the mode fault feature is not available for detecting system
errors between masters.
15.4.7.2
Bidirectional Mode (MOMI or SISO)
The bidirectional mode is selected when the SPC0 bit is set in SPI Control Register 2 (see Table 15-9.) In
this mode, the SPI uses only one serial data pin for the interface with external device(s). The MSTR bit
decides which pin to use. The MOSI pin becomes the serial data I/O (MOMI) pin for the master mode, and
the MISO pin becomes serial data I/O (SISO) pin for the slave mode. The MISO pin in master mode and
MOSI pin in slave mode are not used by the SPI.
MC9S08JM16 Series Data Sheet, Rev. 2
258
Freescale Semiconductor
Serial Peripheral Interface (S08SPI16V1)
Table 15-9. Normal Mode and Bidirectional Mode
When SPE = 1
Master Mode MSTR = 1
Serial Out
Normal Mode
SPC0 = 0
SPI
SPI
Serial Out
MISO
Serial Out
SPI
MOSI
Serial In
MOSI
Serial In
Bidirectional Mode
SPC0 = 1
Slave Mode MSTR = 0
MOMI
MISO
Serial In
BIDIROE
SPI
BIDIROE
Serial In
Serial Out
SISO
.
The direction of each serial I/O pin depends on the BIDIROE bit. If the pin is configured as an output,
serial data from the shift register is driven out on the pin. The same pin is also the serial input to the shift
register.
The SPSCK is output for the master mode and input for the slave mode.
The SS is the input or output for the master mode, and it is always the input for the slave mode.
The bidirectional mode does not affect SPSCK and SS functions.
NOTE
In bidirectional master mode, with mode fault enabled, both data pins MISO
and MOSI can be occupied by the SPI, though MOSI is normally used for
transmissions in bidirectional mode and MISO is not used by the SPI. If a
mode fault occurs, the SPI is automatically switched to slave mode, in this
case MISO becomes occupied by the SPI and MOSI is not used. This has to
be considered, if the MISO pin is used for another purpose.
15.4.8
Error Conditions
The SPI has one error condition:
• Mode fault error
15.4.8.1
Mode Fault Error
If the SS input becomes low while the SPI is configured as a master, it indicates a system error where more
than one master may be trying to drive the MOSI and SPSCK lines simultaneously. This condition is not
permitted in normal operation, and the MODF bit in the SPI status register is set automatically provided
the MODFEN bit is set.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
259
Serial Peripheral Interface (S08SPI16V1)
In the special case where the SPI is in master mode and MODFEN bit is cleared, the SS pin is not used by
the SPI. In this special case, the mode fault error function is inhibited and MODF remains cleared. In case
the SPI system is configured as a slave, the SS pin is a dedicated input pin. Mode fault error doesn’t occur
in slave mode.
If a mode fault error occurs the SPI is switched to slave mode, with the exception that the slave output
buffer is disabled. So SPSCK, MISO and MOSI pins are forced to be high impedance inputs to avoid any
possibility of conflict with another output driver. A transmission in progress is aborted and the SPI is
forced into idle state.
If the mode fault error occurs in the bidirectional mode for a SPI system configured in master mode, output
enable of the MOMI (MOSI in bidirectional mode) is cleared if it was set. No mode fault error occurs in
the bidirectional mode for the SPI system configured in slave mode.
The mode fault flag is cleared automatically by a read of the SPI Status Register (with MODF set) followed
by a write to SPI Control Register 1. If the mode fault flag is cleared, the SPI becomes a normal master or
slave again.
15.4.9
15.4.9.1
Low Power Mode Options
SPI in Run Mode
In run mode with the SPI system enable (SPE) bit in the SPI control register clear, the SPI system is in a
low-power, disabled state. SPI registers can still be accessed, but clocks to the core of this module are
disabled.
15.4.9.2
SPI in Wait Mode
SPI operation in wait mode depends upon the state of the SPISWAI bit in SPI Control Register 2.
• If SPISWAI is clear, the SPI operates normally when the CPU is in wait mode
• If SPISWAI is set, SPI clock generation ceases and the SPI module enters a power conservation
state when the CPU is in wait mode.
— If SPISWAI is set and the SPI is configured for master, any transmission and reception in
progress stops at wait mode entry. The transmission and reception resumes when the SPI exits
wait mode.
– If SPISWAI is set and the SPI is configured as a slave, any transmission and reception in
progress continues if the SPSCK continues to be driven from the master. This keeps the slave
synchronized to the master and the SPSCK.
If the master transmits data while the slave is in wait mode, the slave will continue to send out
data consistent with the operation mode at the start of wait mode (i.e., if the slave is currently
sending its SPIxDH:SPIxDL to the master, it will continue to send the same byte. Otherwise,
if the slave is currently sending the last data received byte from the master, it will continue to
send each previously receive data from the master byte).
MC9S08JM16 Series Data Sheet, Rev. 2
260
Freescale Semiconductor
Serial Peripheral Interface (S08SPI16V1)
NOTE
Care must be taken when expecting data from a master while the slave is in
wait or stop3 mode. Even though the shift register will continue to operate,
the rest of the SPI is shut down (i.e. a SPRF interrupt will not be generated
until exiting stop or wait mode). Also, the data from the shift register will
not be copied into the SPIxDH:SPIxDL registers until after the slave SPI has
exited wait or stop mode. A SPRF flag and SPIxDH:SPIxDL copy is only
generated if wait mode is entered or exited during a tranmission. If the slave
enters wait mode in idle mode and exits wait mode in idle mode, neither a
SPRF nor a SPIxDH:SPIxDL copy will occur.
15.4.9.3
SPI in Stop Mode
Stop3 mode is dependent on the SPI system. Upon entry to stop3 mode, the SPI module clock is disabled
(held high or low). If the SPI is in master mode and exchanging data when the CPU enters stop mode, the
transmission is frozen until the CPU exits stop mode. After stop, data to and from the external SPI is
exchanged correctly. In slave mode, the SPI will stay synchronized with the master.
The stop mode is not dependent on the SPISWAI bit.
In all other stop modes, the SPI module is completely disabled. After stop, all registers are reset to their
default values, and the SPI module must be re-initialized.
15.4.9.4
Reset
The reset values of registers and signals are described in Section 15.3, “Register Definition.” which details
the registers and their bit-fields.
• If a data transmission occurs in slave mode after reset without a write to SPIxDH:SPIxDL, it will
transmit garbage, or the data last received from the master before the reset.
• Reading from the SPIxDH:SPIxDL after reset will always read zeros.
15.4.9.5
Interrupts
The SPI only originates interrupt requests when the SPI is enabled (SPE bit in SPIxC1 set). The following
is a description of how the SPI makes a request and how the MCU must acknowledge that request. The
interrupt vector offset and interrupt priority are chip dependent.
15.4.10 SPI Interrupts
There are four flag bits, three 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). The SPI match interrupt enable mask bit (SPIMIE) enables interrupts
from the SPI match flag (SPMF). 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) must check the
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
261
Serial Peripheral Interface (S08SPI16V1)
flag bits to determine what event caused the interrupt. The service routine must also clear the flag bit(s)
before returning from the ISR (usually near the beginning of the ISR).
15.4.10.1 MODF
MODF occurs when the master detects an error on the SS pin. The master SPI must be configured for the
MODF feature (see Table 15-2). Once MODF is set, the current transfer is aborted and the following bit is
changed:
• MSTR=0, The master bit in SPIxC1 resets.
The MODF interrupt is reflected in the status register MODF flag. Clearing the flag will also clear the
interrupt. This interrupt will stay active while the MODF flag is set. MODF has an automatic clearing
process which is described in Section 15.3.4, “SPI Status Register (SPIxS).”
15.4.10.2 SPRF
SPRF occurs when new data has been received and copied to the SPI receive data buffer. In 8-bit mode,
SPRF is set only after all 8 bits have been shifted out of the shift register and into SPIxDL. In 16-bit mode,
SPRF is set only after all 16 bits have been shifted out of the shift register and into SPIxDH:SPIxDL.
Once SPRF is set, it does not clear until it is serviced. SPRF has an automatic clearing process which is
described in Section 15.3.4, “SPI Status Register (SPIxS).” In the event that the SPRF is not serviced
before the end of the next transfer (i.e. SPRF remains active throughout another transfer), the latter
transfers will be ignored and no new data will be copied into the SPIxDH:SPIxDL.
15.4.10.3 SPTEF
SPTEF occurs when the SPI transmit buffer is ready to accept new data. In 8-bit mode, SPTEF is set only
after all 8 bits have been moved from SPIxDL into the shifter. In 16-bit mode, SPTEF is set only after all
16 bits have been moved from SPIxDH:SPIxDL into the shifter.
Once SPTEF is set, it does not clear until it is serviced. SPTEF has an automatic clearing process which is
described in Section 15.3.4, “SPI Status Register (SPIxS).
15.4.10.4 SPMF
SPMF occurs when the data in the receive data buffer is equal to the data in the SPI match register. In 8-bit
mode, SPMF is set only after bits 8–0 in the receive data buffer are determined to be equivalent to the value
in SPIxML. In 16-bit mode, SPMF is set after bits 15–0 in the receive data buffer are determined to be
equivalent to the value in SPIxMH:SPIxML.
MC9S08JM16 Series Data Sheet, Rev. 2
262
Freescale Semiconductor
Serial Peripheral Interface (S08SPI16V1)
15.5
Initialization/Application Information
15.5.1
SPI Module Initialization Example
15.5.1.1
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 (SPIxC1) 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 (SPIxC2) to enable additional SPI functions such as the SPI match
interrupt feature, the master mode-fault function, and bidirectional mode output. 8- or 16-bit mode
select and other optional features are controlled here as well.
3. Update the baud rate register (SPIxBR) to set the prescaler and bit rate divisor for an SPI master.
4. Update the hardware match register (SPIxMH:SPIxML) with the value to be compared to the
receive data register for triggering an interrupt if hardware match interrupts are enabled.
5. In the master, read SPIxS while SPTEF = 1, and then write to the transmit data register
(SPIxDH:SPIxDL) to begin transfer.
15.5.1.2
Pseudo—Code Example
In this example, the SPI module will be set up for master mode with only hardware match interrupts
enabled. The SPI will run in 16-bit mode 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.
SPIxC1=0x54(%01010100)
Bit 7
SPIE
= 0
Disables receive and mode fault interrupts
Bit 6
SPE
= 1
Enables the SPI system
Bit 5
SPTIE
= 0
Disables 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
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
263
Serial Peripheral Interface (S08SPI16V1)
SPIxC2 = 0xC0(%11000000)
Bit 7
SPMIE
= 1
SPI hardware match interrupt enabled
Bit 6
SPIMODE
= 1
Configures SPI for 16-bit mode
= 0
Unimplemented
= 0
Disables mode fault function
Bit 5
Bit 4
MODFEN
Bit 3
BIDIROE
Bit 2
= 0
SPI data I/O pin acts as input
= 0
Unimplemented
Bit 1
SPISWAI
= 0
SPI clocks operate in wait mode
Bit 0
SPC0
= 0
uses separate pins for data input and output
SPIxBR = 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
SPIxS = 0x00(%00000000)
Bit 7
SPRF
= 0
Flag is set when receive data buffer is full
Bit 6
SPMF
= 0
Flag is set when SPIMH/L = receive data buffer
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
SPIxMH = 0xXX
In 16-bit mode, this register holds bits 8–15 of the hardware match buffer. In 8-bit mode, writes to this register will be
ignored.
SPIxML = 0xXX
Holds bits 0–7 of the hardware match buffer.
SPIxDH = 0xxx
In 16-bit mode, this register holds bits 8–15 of the data to be transmitted by the transmit buffer and received by the
receive buffer.
SPIxDL = 0xxx
Holds bits 0–7 of the data to be transmitted by the transmit buffer and received by the receive buffer.
MC9S08JM16 Series Data Sheet, Rev. 2
264
Freescale Semiconductor
Serial Peripheral Interface (S08SPI16V1)
RESET
INITIALIZE SPI
SPIxC1 = 0x54
SPIxC2 = 0xC0
SPIxBR = 0x00
SPIxMH = 0xXX
YES
SPTEF = 1
?
NO
YES
WRITE TO
SPIxDH:SPIxDL
SPRF = 1
?
NO
YES
READ
SPIxDH:SPIxDL
SPMF = 1
?
NO
YES
READ SPMF WHILE SET
TO CLEAR FLAG,
THEN WRITE A 1 TO IT
CONTINUE
Figure 15-16. Initialization Flowchart Example for SPI Master Device in 16-bit Mode
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
265
Serial Peripheral Interface (S08SPI16V1)
MC9S08JM16 Series Data Sheet, Rev. 2
266
Freescale Semiconductor
Chapter 16
Timer/Pulse-Width Modulator (S08TPMV2)
16.1
Introduction
The MC9S08JM16 series includes two independent timer/PWM (TPM) modules (up to 6 channels) that
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.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
267
Chapter 16 Timer/Pulse-Width Modulator (S08TPMV2)
pullup
CPU
HCS08 SYSTEM CONTROL
RESETS AND INTERRUPTS
MODES OF OPERATION
POWER MANAGEMENT
COP
IRQ
8-/16-BIT SERIAL PERIPHERAL
INTERFACE MODULE (SPI2)
SERIAL COMMUNICATIONS
VDDAD
USER Flash (IN BYTES)
MC9S08JM60 = 60,912
MC9S08JM32 = 32,768
RxD2
TxD2
IIC MODULE (IIC)
SDA
SCL
12-CHANNEL, 12-BIT
ANALOG-TO-DIGITAL
CONVERTER (ADC)
VSSAD
VREFL
VREFH
SS2
SPSCK2
MOSI2
MISO2
INTERFACE MODULE (SCI2)
LVD
PORT B
BDC
FULL SPEED
USB
USB ENDPOINT TRANSCEIVER
RAM
PORT C
IRQ/TPMCLK
USB SIE
6
ACMPO
VDD
VSS
VUSB33
LOW-POWER OSCILLATOR
SYSTEM
VOLTAGE
REGULATOR
SERIAL COMMUNICATIONS
INTERFACE MODULE (SCI1)
2-CHANNEL TIMER/PWM
MODULE (TPM2)
PTE5/MOSI1
7-BIT KEYBOARD
INTERRUPT MODULE (KBI)
PTE4/MISO1
TPM1CH0
TPM1CHx
PORT E
TPMCLK
TPM1CH1
2
PTE3/TPM1CH1
PTE2/TPM1CH0
RxD1
TxD1
PTE1/RxD1
PTE0/TxD1
TPMCLK
TPM2CH1
TPM2CH0
PTF7
PTF6
PTF5/TPM2CH1
PTF4/TPM2CH0
KBIPx
USB 3.3 V VOLTAGE REGULATOR
REAL-TIME COUNTER
(RTC)
PTE6/SPSCK1
MOSI1
KBIPx
EXTAL
XTAL
PORT F
VSSOSC
MODULE (TPM1)
PTD2/KBIP2/ACMPO
PTE7/SS1
SPSCK1
MISO1
4-CHANNEL TIMER/PWM
PTC5/RxD2
PTC4
PTC3/TxD2
PTC2
PTD1/ADP9/ACMP–
PTD0/ADP8/ACMP+
ACMP+
3
PTF1/TPM1CH3
PTF0/TPM1CH2
4
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 must not be driven above VDD.
4. Pin contains integrated pullup device.
5. When pin functions as KBI (KBIPEn = 1) and associated pin is configured to enable the
pullup device, KBEDGn can be used to reconfigure the pullup as a pulldown device.
PTG5/EXTAL
PORT G
MULTI-PURPOSE CLOCK
GENERATOR (MCG)
8-/16-BIT SERIAL PERIPHERAL
INTERFACE MODULE (SPI16)
PTB5/KBIP5/ADP5
PTB4/KBIP4/ADP4
PTB3/SS2/ADP3
PTB2/SPSCK2/ADP2
PTB1/MOSI2/ADP1
PTB0/MISO2/ADP0
PTD7
SS1
USER RAM (IN BYTES)
MC9S08JM60 = 4096
MC9S08JM32 = 2048
PTA5, PTA0
2
ACMP–
ANALOG COMPARATOR
(ACMP)
2
PTC1/SDA
PTC0/SCL
PORT D
RESET
PORT A
HCS08 CORE
BKGD/MS
USBDP
USBDN
ON-CHIP ICE AND
DEBUG MODULE (DBG)
PTG4/XTAL
PTG3/KBIP7
PTG2/KBIP6
PTG1/KBIP1
PTG0/KBIP0
Figure 16-1. MC9S08JM16 Series Block Diagram Highlighting the TPM Blocks and Pins
MC9S08JM16 Series Data Sheet, Rev. 2
268
Freescale Semiconductor
16.1.1
Features
The TPM includes these distinctive features:
• One to eight channels:
— Each channel may be input capture, output compare, or 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
• Module may be configured for buffered, center-aligned pulse-width-modulation (CPWM) on all
channels
• Timer clock source selectable as prescaled bus clock, fixed system clock, or an external clock pin
— Prescale taps for divide-by 1, 2, 4, 8, 16, 32, 64, or 128
— Fixed system clock source are synchronized to the bus clock by an on-chip synchronization
circuit
— External clock pin may be shared with any timer channel pin or a separated input pin
• 16-bit free-running or modulo up/down count operation
• Timer system enable
• One interrupt per channel plus terminal count interrupt
16.1.2
Modes of Operation
In general, TPM channels may be independently configured to operate in input capture, output compare,
or edge-aligned PWM modes. A control bit allows the whole TPM (all channels) to switch to
center-aligned PWM mode. When center-aligned PWM mode is selected, input capture, output compare,
and edge-aligned PWM functions are not available on any channels of this TPM module.
When the microcontroller is in active BDM background or BDM foreground mode, the TPM temporarily
suspends all counting until the microcontroller returns to normal user operating mode. During stop mode,
all system clocks, including the main oscillator, are stopped; therefore, the TPM is effectively disabled
until clocks resume. During wait mode, the TPM continues to operate normally. Provided the TPM does
not need to produce a real time reference or provide the interrupt source(s) needed to wake the MCU from
wait mode, the user can save power by disabling TPM functions before entering wait mode.
• Input capture mode
When a selected edge event occurs on the associated MCU pin, the current value of the 16-bit timer
counter is captured into the channel value register and an interrupt flag bit is set. Rising edges,
falling edges, any edge, or no edge (disable channel) may be selected as the active edge which
triggers the input capture.
• Output compare mode
When the value in the timer counter register matches the channel value register, an interrupt flag
bit is set, and a selected output action is forced on the associated MCU pin. The output compare
action may be selected to force the pin to zero, force the pin to one, toggle the pin, or ignore the
pin (used for software timing functions).
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
269
•
•
Edge-aligned PWM mode
The value of a 16-bit modulo register plus 1 sets the period of the PWM output signal. The channel
value register sets the duty cycle of the PWM output signal. The user may also choose the polarity
of the PWM output signal. Interrupts are available at the end of the period and at the duty-cycle
transition point. This type of PWM signal is called edge-aligned because the leading edges of all
PWM signals are aligned with the beginning of the period, which is the same for all channels within
a TPM.
Center-aligned PWM mode
Twice the value of a 16-bit modulo register sets the period of the PWM output, and the
channel-value register sets the half-duty-cycle duration. The timer counter counts up until it
reaches the modulo value and then counts down until it reaches zero. As the count matches the
channel value register while counting down, the PWM output becomes active. When the count
matches the channel value register while counting up, the PWM output becomes inactive. This type
of PWM signal is called center-aligned because the centers of the active duty cycle periods for all
channels are aligned with a count value of zero. This type of PWM is required for types of motors
used in small appliances.
This is a high-level description only. Detailed descriptions of operating modes are in later sections.
16.1.3
Block Diagram
The TPM uses one input/output (I/O) pin per channel, TPMxCHn (timer channel n) where n is the channel
number (1-8). The TPM shares its I/O pins with general purpose I/O port pins (refer to I/O pin descriptions
in full-chip specification for the specific chip implementation).
Figure 16-2 shows the TPM structure. The central component of the TPM is the 16-bit counter that can
operate as a free-running counter or a modulo up/down counter. 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 effectively make the counter free running).
Software can read the counter value at any time without affecting the counting sequence. Any write to
either half of the TPMxCNT counter resets the counter, regardless of the data value written.
MC9S08JM16 Series Data Sheet, Rev. 2
270
Freescale Semiconductor
BUS CLOCK
FIXED SYSTEM CLOCK
SYNC
EXTERNAL CLOCK
CLOCK SOURCE
SELECT
OFF, BUS, FIXED
SYSTEM CLOCK, EXT
PRESCALE AND SELECT
³1, 2, 4, 8, 16, 32, 64,
or ³128
CLKSB:CLKSA
PS2:PS1:PS0
CPWMS
16-BIT COUNTER
TOF
COUNTER RESET
TOIE
INTERRUPT
LOGIC
16-BIT COMPARATOR
TPMxMODH:TPMxMODL
CHANNEL 0
ELS0B
ELS0A
PORT
LOGIC
TPMxCH0
16-BIT COMPARATOR
CH0F
TPMxC0VH:TPMxC0VL
INTERNAL BUS
16-BIT LATCH
CHANNEL 1
MS0B
MS0A
ELS1B
ELS1A
CH0IE
INTERRUPT
LOGIC
PORT
LOGIC
TPMxCH1
16-BIT COMPARATOR
CH1F
TPMxC1VH:TPMxC1VL
16-BIT LATCH
MS1B
CH1IE
MS1A
INTERRUPT
LOGIC
Up to 8 channels
CHANNEL 7
ELS7B
ELS7A
PORT
LOGIC
TPMxCH7
16-BIT COMPARATOR
CH7F
TPMxC7VH:TPMxC7VL
16-BIT LATCH
MS7B
MS7A
CH7IE
INTERRUPT
LOGIC
Figure 16-2. TPM Block Diagram
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
271
The TPM channels are programmable independently as input capture, output compare, or edge-aligned
PWM channels. Alternately, the TPM can be configured to produce CPWM outputs on all channels. When
the TPM is configured for CPWMs, the counter operates as an up/down counter; input capture, output
compare, and EPWM functions are not practical.
If a channel is configured as input capture, an internal pullup device may be enabled for that channel. The
details of how a module interacts with pin controls depends upon the chip implementation because the I/O
pins and associated general purpose I/O controls are not part of the module. Refer to the discussion of the
I/O port logic in a full-chip specification.
Because center-aligned PWMs are usually used to drive 3-phase AC-induction motors and brushless DC
motors, they are typically used in sets of three or six channels.
16.2
Signal Description
Table 16-1 shows the user-accessible signals for the TPM. The number of channels may be varied from
one to eight. When an external clock is included, it can be shared with the same pin as any TPM channel;
however, it could be connected to a separate input pin. Refer to the I/O pin descriptions in full-chip
specification for the specific chip implementation.
Table 16-1. Signal Properties
Name
Function
EXTCLK1
2
TPMxCHn
External clock source which may be selected to drive the TPM counter.
I/O pin associated with TPM channel n
1
When preset, this signal can share any channel pin; however depending upon full-chip
implementation, this signal could be connected to a separate external pin.
2 n=channel number (1 to 8)
Refer to documentation for the full-chip for details about reset states, port connections, and whether there
is any pullup device on these pins.
TPM channel pins can be associated with general purpose I/O pins and have passive pullup devices which
can be enabled with a control bit when the TPM or general purpose I/O controls have configured the
associated pin as an input. When no TPM function is enabled to use a corresponding pin, the pin reverts
to being controlled by general purpose I/O controls, including the port-data and data-direction registers.
Immediately after reset, no TPM functions are enabled, so all associated pins revert to general purpose I/O
control.
16.2.1
Detailed Signal Descriptions
This section describes each user-accessible pin signal in detail. Although Table 16-1 grouped all channel
pins together, any TPM pin can be shared with the external clock source signal. Since I/O pin logic is not
part of the TPM, refer to full-chip documentation for a specific derivative for more details about the
interaction of TPM pin functions and general purpose I/O controls including port data, data direction, and
pullup controls.
MC9S08JM16 Series Data Sheet, Rev. 2
272
Freescale Semiconductor
16.2.1.1
EXTCLK — External Clock Source
Control bits in the timer status and control register allow the user to select nothing (timer disable), the
bus-rate clock (the normal default source), a crystal-related clock, or an external clock as the clock which
drives the TPM prescaler and subsequently the 16-bit TPM counter. The external clock source is
synchronized in the TPM. The bus clock clocks the synchronizer; the frequency of the external source must
be no more than one-fourth the frequency of the bus-rate clock, to meet Nyquist criteria and allowing for
jitter.
The external clock signal shares the same pin as a channel I/O pin, so the channel pin will not be usable
for channel I/O function when selected as the external clock source. It is the user’s responsibility to avoid
such settings. If this pin is used as an external clock source (CLKSB:CLKSA = 1:1), the channel can still
be used in output compare mode as a software timer (ELSnB:ELSnA = 0:0).
16.2.1.2
TPMxCHn — TPM Channel n I/O Pin(s)
Each TPM channel is associated with an I/O pin on the MCU. The function of this pin depends on the
channel configuration. The TPM pins share with general purpose I/O pins, where each pin has a port data
register bit, and a data direction control bit, and the port has optional passive pullups which may be enabled
whenever a port pin is acting as an input.
The TPM channel does not control the I/O pin when (ELSnB:ELSnA = 0:0) or when (CLKSB:CLKSA =
0:0) so it normally reverts to general purpose I/O control. When CPWMS = 1 (and ELSnB:ELSnA not =
0:0), all channels within the TPM are configured for center-aligned PWM and the TPMxCHn pins are all
controlled by the TPM system. When CPWMS=0, the MSnB:MSnA control bits determine whether the
channel is configured for input capture, output compare, or edge-aligned PWM.
When a channel is configured for input capture (CPWMS=0, MSnB:MSnA = 0:0 and ELSnB:ELSnA not
= 0:0), the TPMxCHn pin is forced to act as an edge-sensitive input to the TPM. ELSnB:ELSnA control
bits determine what polarity edge or edges will trigger input-capture events. A synchronizer based on the
bus clock is used to synchronize input edges to the bus clock. This implies the minimum pulse width—that
can be reliably detected—on an input capture pin is four bus clock periods (with ideal clock pulses as near
as two bus clocks can be detected). TPM uses this pin as an input capture input to override the port data
and data direction controls for the same pin.
When a channel is configured for output compare (CPWMS=0, MSnB:MSnA = 0:1 and ELSnB:ELSnA
not = 0:0), the associated data direction control is overridden, the TPMxCHn pin is considered an output
controlled by the TPM, and the ELSnB:ELSnA control bits determine how the pin is controlled. The
remaining three combinations of ELSnB:ELSnA determine whether the TPMxCHn pin is toggled, cleared,
or set each time the 16-bit channel value register matches the timer counter.
When the output compare toggle mode is initially selected, the previous value on the pin is driven out until
the next output compare event—then the pin is toggled.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
273
When a channel is configured for edge-aligned PWM (CPWMS=0, MSnB=1 and ELSnB:ELSnA not =
0:0), the data direction is overridden, the TPMxCHn pin is forced to be an output controlled by the TPM,
and ELSnA controls the polarity of the PWM output signal on the pin. When ELSnB:ELSnA=1:0, the
TPMxCHn pin is forced high at the start of each new period (TPMxCNT=0x0000), and the pin is forced
low when the channel value register matches the timer counter. When ELSnA=1, the TPMxCHn pin is
forced low at the start of each new period (TPMxCNT=0x0000), and the pin is forced high when the
channel value register matches the timer counter.
TPMxMODH:TPMxMODL = 0x0008
TPMxMODH:TPMxMODL = 0x0005
TPMxCNTH:TPMxCNTL...
0
1
2
3
4
5
6
7
8
0
1
2
...
2
...
TPMxCHn
CHnF BIT
TOF BIT
Figure 16-3. High-True Pulse of an Edge-Aligned PWM
TPMxMODH:TPMxMODL = 0x0008
TPMxMODH:TPMxMODL = 0x0005
TPMxCNTH:TPMxCNTL...
0
1
2
3
4
5
6
7
8
0
1
TPMxCHn
CHnF BIT
TOF BIT
Figure 16-4. Low-True Pulse of an Edge-Aligned PWM
MC9S08JM16 Series Data Sheet, Rev. 2
274
Freescale Semiconductor
When the TPM is configured for center-aligned PWM (and ELSnB:ELSnA not = 0:0), the data direction
for all channels in this TPM are overridden, the TPMxCHn pins are forced to be outputs controlled by the
TPM, and the ELSnA bits control the polarity of each TPMxCHn output. If ELSnB:ELSnA=1:0, the
corresponding TPMxCHn pin is cleared when the timer counter is counting up, and the channel value
register matches the timer counter; the TPMxCHn pin is set when the timer counter is counting down, and
the channel value register matches the timer counter. If ELSnA=1, the corresponding TPMxCHn pin is set
when the timer counter is counting up and the channel value register matches the timer counter; the
TPMxCHn pin is cleared when the timer counter is counting down and the channel value register matches
the timer counter.
TPMxMODH:TPMxMODL = 0x0008
TPMxMODH:TPMxMODL = 0x0005
TPMxCNTH:TPMxCNTL ...
7
8
7
6
5
4
3
2
1
0
1
2
3
4
5
6
7
8
7
6
5
...
7
8
7
6
5
...
TPMxCHn
CHnF BIT
TOF BIT
Figure 16-5. High-True Pulse of a Center-Aligned PWM
TPMxMODH:TPMxMODL = 0x0008
TPMxMODH:TPMxMODL = 0x0005
TPMxCNTH:TPMxCNTL ...
7
8
7
6
5
4
3
2
1
0
1
2
3
4
5
6
TPMxCHn
CHnF BIT
TOF BIT
Figure 16-6. Low-True Pulse of a Center-Aligned PWM
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
275
16.3
Register Definition
This section consists of register descriptions in address order. A typical MCU system may contain multiple
TPMs, and each TPM may have one to eight channels, 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. TPM1C2SC would be the status and control register for channel 2 of timer 1.
16.3.1
TPM Status and Control Register (TPMxSC)
TPMxSC contains the overflow status flag and control bits used to configure the interrupt enable, TPM
configuration, clock source, and prescale factor. These controls relate to all channels within this timer
module.
7
R
TOF
W
0
Reset
0
6
5
4
3
2
1
0
TOIE
CPWMS
CLKSB
CLKSA
PS2
PS1
PS0
0
0
0
0
0
0
0
Figure 16-7. TPM Status and Control Register (TPMxSC)
Table 16-2. TPMxSC Field Descriptions
Field
Description
7
TOF
Timer overflow flag. This read/write flag is set when the TPM counter resets to 0x0000 after reaching the modulo
value programmed in the TPM counter modulo registers. Clear TOF by reading the TPM status and control
register when TOF is set and then writing a logic 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. This is done so a TOF interrupt request cannot be lost during the clearing sequence for a
previous TOF. Reset clears TOF. Writing a logic 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 one. Reset clears TOIE.
0 TOF interrupts inhibited (use for software polling)
1 TOF interrupts enabled
5
CPWMS
Center-aligned PWM select. When present, this read/write bit selects CPWM operating mode. By default, 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 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 channels operate in center-aligned PWM mode.
MC9S08JM16 Series Data Sheet, Rev. 2
276
Freescale Semiconductor
Table 16-2. TPMxSC Field Descriptions (continued)
Field
Description
4–3
Clock source selects. As shown in Table 16-3, this 2-bit field is used to disable the TPM system or select one of
CLKS[B:A] three clock sources to drive the counter prescaler. The fixed system clock source is only meaningful in systems
with a PLL-based or FLL-based system clock. When there is no PLL or FLL, the fixed-system clock source is the
same as the bus rate clock. The external source is synchronized to the bus clock by TPM module, and the fixed
system clock source (when a PLL or FLL is present) is synchronized to the bus clock by an on-chip
synchronization circuit. When a PLL or FLL is present but not enabled, the fixed-system clock source is the same
as the bus-rate clock.
2–0
PS[2:0]
Prescale factor select. This 3-bit field selects one of 8 division factors for the TPM clock input as shown in
Table 16-4. This prescaler is located after any clock source synchronization or clock source selection so it affects
the clock source selected to drive the TPM system. The new prescale factor will affect the clock source on the
next system clock cycle after the new value is updated into the register bits.
Table 16-3. TPM-Clock-Source Selection
CLKSB:CLKSA
TPM Clock Source to Prescaler Input
00
No clock selected (TPM counter disable)
01
Bus rate clock
10
Fixed system clock
11
External source
Table 16-4. Prescale Factor Selection
16.3.2
PS2:PS1:PS0
TPM Clock Source Divided-by
000
1
001
2
010
4
011
8
100
16
101
32
110
64
111
128
TPM-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 half is read. This allows coherent 16-bit reads in either big-endian or
little-endian order which makes this more friendly to various compiler implementations. The coherency
mechanism is automatically restarted by an MCU reset or any write to the timer status/control register
(TPMxSC).
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
277
Reset clears the TPM counter registers. Writing any value to TPMxCNTH or TPMxCNTL also clears the
TPM counter (TPMxCNTH:TPMxCNTL) and resets the coherency mechanism, regardless of the data
involved in the write.
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 16-8. TPM 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 16-9. TPM Counter Register Low (TPMxCNTL)
When BDM is active, the timer counter is frozen (this is the value that will be read by user); the coherency
mechanism is frozen such that the buffer latches remain in the state they were in when the BDM became
active, even if one or both counter halves are read while BDM is active. This assures that if the user was
in the middle of reading a 16-bit register when BDM became active, it will read the appropriate value from
the other half of the 16-bit value after returning to normal execution.
In BDM mode, writing any value to TPMxSC, TPMxCNTH or TPMxCNTL registers resets the read
coherency mechanism of the TPMxCNTH:L registers, regardless of the data involved in the write.
16.3.3
TPM 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, and
the overflow flag (TOF) becomes set. Writing to TPMxMODH or TPMxMODL inhibits the TOF bit 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).
Writing to either byte (TPMxMODH or TPMxMODL) latches the value into a buffer and the registers are
updated with the value of their write buffer according to the value of CLKSB:CLKSA bits, so:
• If (CLKSB:CLKSA = 0:0), then the registers are updated when the second byte is written
• If (CLKSB:CLKSA not = 0:0), then the registers are updated after both bytes were written, and the
TPM counter changes from (TPMxMODH:TPMxMODL - 1) to (TPMxMODH:TPMxMODL). If
the TPM counter is a free-running counter, the update is made when the TPM counter changes from
0xFFFE to 0xFFFF
The latching mechanism may be manually reset by writing to the TPMxSC address (whether BDM is
active or not).
MC9S08JM16 Series Data Sheet, Rev. 2
278
Freescale Semiconductor
When BDM is active, the coherency mechanism is frozen (unless reset by writing to TPMxSC register)
such that the buffer latches remain in the state they were in when the BDM became active, even if one or
both halves of the modulo register are written while BDM is active. Any write to the modulo registers
bypasses the buffer latches and directly writes to the modulo register while BDM is active.
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 16-10. TPM 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 16-11. TPM Counter Modulo Register Low (TPMxMODL)
Reset the TPM counter before writing to the TPM modulo registers to avoid confusion about when the first
counter overflow will occur.
16.3.4
TPM Channel n Status and Control Register (TPMxCnSC)
TPMxCnSC contains the channel-interrupt-status flag and control bits used to configure the interrupt
enable, channel configuration, and pin function.
7
R
6
5
4
3
2
CHnIE
MSnB
MSnA
ELSnB
ELSnA
0
0
0
0
0
CHnF
W
0
Reset
0
1
0
0
0
0
0
= Unimplemented or Reserved
Figure 16-12. TPM Channel n Status and Control Register (TPMxCnSC)
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
279
Table 16-5. TPMxCnSC Field Descriptions
Field
Description
7
CHnF
Channel n flag. When channel n is an input-capture channel, this read/write bit is set when an active edge occurs
on the channel n pin. When channel n is an output compare or edge-aligned/center-aligned PWM channel, CHnF
is set when the value in the TPM counter registers matches the value in the TPM channel n value registers. When
channel n is an edge-aligned/center-aligned PWM channel and the duty cycle is set to 0% or 100%, CHnF will not
be set even when the value in the TPM counter registers matches the value in the TPM channel n value registers.
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 logic 0 to CHnF. If another interrupt request occurs
before the clearing sequence is complete, the sequence is reset so CHnF remains set after the clear sequence
completed for the earlier CHnF. This is done so a CHnF interrupt request cannot be lost due to clearing a previous
CHnF.
Reset clears the CHnF bit. Writing a logic 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 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 for 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. Refer to the summary of channel mode and setup controls in Table 16-6.
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 16-6 for a summary of channel mode and setup
controls.
Note: 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.
3–2
ELSnB
ELSnA
Edge/level select bits. Depending upon the operating mode for the timer channel as set by CPWMS:MSnB:MSnA
and shown in Table 16-6, 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 not related to any timer
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.
Table 16-6. Mode, Edge, and Level Selection
CPWMS
MSnB:MSnA
ELSnB:ELSnA
X
XX
00
Mode
Configuration
Pin not used for TPM - revert to general
purpose I/O or other peripheral control
MC9S08JM16 Series Data Sheet, Rev. 2
280
Freescale Semiconductor
Table 16-6. Mode, Edge, and Level Selection
CPWMS
MSnB:MSnA
ELSnB:ELSnA
Mode
Configuration
0
00
01
Input capture
Capture on rising edge
only
01
10
Capture on falling edge
only
11
Capture on rising or
falling edge
01
1X
Output compare
10
Clear output on
compare
11
Set output on compare
10
Edge-aligned
PWM
X1
1
XX
High-true pulses (clear
output on compare)
Low-true pulses (set
output on compare)
10
Center-aligned
PWM
X1
16.3.5
Toggle output on
compare
High-true pulses (clear
output on compare-up)
Low-true pulses (set
output on compare-up)
TPM 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 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 16-13. TPM 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 16-14. TPM 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 half is read. This latching mechanism also resets
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
281
(becomes unlatched) when the TPMxCnSC register is written (whether BDM mode is active or not). Any
write to the channel registers will be ignored during the input capture mode.
When BDM is active, the coherency mechanism is frozen (unless reset by writing to TPMxCnSC register)
such that the buffer latches remain in the state they were in when the BDM became active, even if one or
both halves of the channel register are read while BDM is active. This assures that if the user was in the
middle of reading a 16-bit register when BDM became active, it will read the appropriate value from the
other half of the 16-bit value after returning to normal execution. The value read from the TPMxCnVH
and TPMxCnVL registers in BDM mode is the value of these registers and not the value of their read
buffer.
In output compare or PWM modes, writing to either byte (TPMxCnVH or TPMxCnVL) latches the value
into a buffer. After both bytes are written, they are transferred as a coherent 16-bit value into the
timer-channel registers according to the value of CLKSB:CLKSA bits and the selected mode, so:
• If (CLKSB:CLKSA = 0:0), then the registers are updated when the second byte is written.
• If (CLKSB:CLKSA not = 0:0 and in output compare mode) then the registers are updated after the
second byte is written and on the next change of the TPM counter (end of the prescaler counting).
• If (CLKSB:CLKSA not = 0:0 and in EPWM or CPWM modes), then the registers are updated after
the both bytes were written, and the TPM counter changes from (TPMxMODH:TPMxMODL - 1)
to (TPMxMODH:TPMxMODL). If the TPM counter is a free-running counter then the update is
made when the TPM counter changes from 0xFFFE to 0xFFFF.
The latching mechanism may be manually reset by writing to the TPMxCnSC register (whether BDM
mode is active or not). This latching mechanism allows coherent 16-bit writes in either big-endian or
little-endian order which is friendly to various compiler implementations.
When BDM is active, the coherency mechanism is frozen such that the buffer latches remain in the state
they were in when the BDM became active even if one or both halves of the channel register are written
while BDM is active. Any write to the channel registers bypasses the buffer latches and directly write to
the channel register while BDM is active. The values written to the channel register while BDM is active
are used for PWM & output compare operation once normal execution resumes. Writes to the channel
registers while BDM is active do not interfere with partial completion of a coherency sequence. After the
coherency mechanism has been fully exercised, the channel registers are updated using the buffered values
written (while BDM was not active) by the user.
16.4
Functional Description
All TPM functions are associated with a central 16-bit counter which allows flexible selection of the clock
source and prescale factor. There is also a 16-bit modulo register associated with the main counter.
The CPWMS control bit chooses between center-aligned PWM operation for all channels in the TPM
(CPWMS=1) or general purpose timing functions (CPWMS=0) where each channel can independently be
configured to operate in input capture, output compare, or edge-aligned PWM mode. The CPWMS control
bit is located in the main TPM status and control register because it affects all channels within the TPM
and influences the way the main counter operates. (In CPWM mode, the counter changes to an up/down
mode rather than the up-counting mode used for general purpose timer functions.)
MC9S08JM16 Series Data Sheet, Rev. 2
282
Freescale Semiconductor
The following sections describe the main 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 upon the operating mode, these topics will be covered in the associated mode
explanation sections.
16.4.1
Counter
All timer functions are based on the main 16-bit counter (TPMxCNTH:TPMxCNTL). This section
discusses selection of the clock source, end-of-count overflow, up-counting vs. up/down counting, and
manual counter reset.
16.4.1.1
Counter Clock Source
The 2-bit field, CLKSB:CLKSA, in the timer status and control register (TPMxSC) selects one of three
possible clock sources or OFF (which effectively disables the TPM). See Table 16-3. After any MCU reset,
CLKSB:CLKSA=0:0 so no clock source is selected, and the TPM is in a very low power state. These
control bits may be read or written at any time and disabling the timer (writing 00 to the CLKSB:CLKSA
field) does not affect the values in the counter or other timer registers.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
283
Table 16-7. TPM Clock Source Selection
CLKSB:CLKSA
TPM Clock Source to Prescaler Input
00
No clock selected (TPM counter disabled)
01
Bus rate clock
10
Fixed system clock
11
External source
The bus rate clock is the main system bus clock for the MCU. This clock source requires no
synchronization because it is the clock that is used for all internal MCU activities including operation of
the CPU and buses.
In MCUs that have no PLL and FLL or the PLL and FLL are not engaged, the fixed system clock source
is the same as the bus-rate-clock source, and it does not go through a synchronizer. When a PLL or FLL
is present and engaged, a synchronizer is required between the crystal divided-by two clock source and the
timer counter so counter transitions will be properly aligned to bus-clock transitions. A synchronizer will
be used at chip level to synchronize the crystal-related source clock to the bus clock.
The external clock source may be connected to any TPM channel pin. This clock source always has to pass
through a synchronizer to assure that counter transitions are properly aligned to bus clock transitions. The
bus-rate clock drives the synchronizer; therefore, to meet Nyquist criteria even with jitter, the frequency
of the external clock source must not be faster than the bus rate divided-by four. With ideal clocks the
external clock can be as fast as bus clock divided by four.
When the external clock source shares the TPM channel pin, this pin should not be used for other channel
timing functions. For example, it would be ambiguous to configure channel 0 for input capture when the
TPM channel 0 pin was also being used as the timer external clock source. (It is the user’s responsibility
to avoid such settings.) The TPM channel could still be used in output compare mode for software timing
functions (pin controls set not to affect the TPM channel pin).
16.4.1.2
Counter Overflow and Modulo Reset
An interrupt flag and enable are associated with the 16-bit main counter. The 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 generated whenever the TOF flag is equal to one.
The conditions causing TOF to become set depend on whether the TPM is configured for center-aligned
PWM (CPWMS=1). In the simplest mode, there is no modulus limit and the TPM is not in CPWMS=1
mode. In this case, 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 TPM is in center-aligned PWM mode (CPWMS=1), the TOF flag gets set as the counter changes
direction at the end of the count value set in the modulus register (that is, at the transition from the value
set in the modulus register to 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).
MC9S08JM16 Series Data Sheet, Rev. 2
284
Freescale Semiconductor
16.4.1.3
Counting Modes
The main timer 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 timer 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.
When center-aligned PWM operation is specified, the counter counts up from 0x0000 through its terminal
count and then down to 0x0000 where it changes back to up counting. Both 0x0000 and the terminal count
value are normal length counts (one timer clock period long). In this mode, the timer overflow flag (TOF)
becomes set at the end of the terminal-count period (as the count changes to the next lower count value).
16.4.1.4
Manual Counter Reset
The main timer counter can be manually reset at any time by writing any value to either half of
TPMxCNTH or TPMxCNTL. Resetting the counter in this manner also resets the coherency mechanism
in case only half of the counter was read before resetting the count.
16.4.2
Channel Mode Selection
Provided CPWMS=0, 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 edge-aligned PWM.
16.4.2.1
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.
In input capture mode, the TPMxCnVH and TPMxCnVL registers are read only.
When either half of the 16-bit capture register is read, the other half is latched into a buffer to support
coherent 16-bit accesses in big-endian or little-endian 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) which may optionally generate a CPU interrupt request.
While in BDM, the input capture function works as configured by the user. When an external event occurs,
the TPM latches the contents of the TPM counter (which is frozen because of the BDM mode) into the
channel value registers and sets the flag bit.
16.4.2.2
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.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
285
In output compare mode, values are transferred to the corresponding timer channel registers only after both
8-bit halves of a 16-bit register have been written and according to the value of CLKSB:CLKSA bits, so:
• If (CLKSB:CLKSA = 0:0), the registers are updated when the second byte is written
• If (CLKSB:CLKSA not = 0:0), the registers are updated at the next change of the TPM counter
(end of the prescaler counting) after the second byte is written.
The coherency sequence can be manually reset by writing to the channel status/control register
(TPMxCnSC).
An output compare event sets a flag bit (CHnF) which may optionally generate a CPU-interrupt request.
16.4.2.3
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 value of the modulus register
(TPMxMODH:TPMxMODL) plus 1. The duty cycle is determined by the setting in the timer channel
register (TPMxCnVH:TPMxCnVL). The polarity of this PWM signal is determined by the setting in the
ELSnA control bit. 0% and 100% duty cycle cases are possible.
The output compare value in the TPM channel registers determines the pulse width (duty cycle) of the
PWM signal (Figure 16-15). 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
TPMxCHn
OUTPUT
COMPARE
OUTPUT
COMPARE
OUTPUT
COMPARE
Figure 16-15. PWM Period and Pulse Width (ELSnA=0)
When the channel value register is set to 0x0000, the duty cycle is 0%. 100% duty cycle can be achieved
by setting the timer-channel register (TPMxCnVH:TPMxCnVL) to a value greater than the modulus
setting. This implies that the modulus setting must be less than 0xFFFF in order to get 100% duty cycle.
Because the TPM may be used in an 8-bit MCU, 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
TPMxCnVH and TPMxCnVL, actually write to buffer registers. In edge-aligned PWM mode, values are
transferred to the corresponding timer-channel registers according to the value of CLKSB:CLKSA bits, so:
• If (CLKSB:CLKSA = 0:0), the registers are updated when the second byte is written
• If (CLKSB:CLKSA not = 0:0), the registers are updated after the both bytes were written, and the
TPM counter changes from (TPMxMODH:TPMxMODL - 1) to (TPMxMODH:TPMxMODL). If
MC9S08JM16 Series Data Sheet, Rev. 2
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Freescale Semiconductor
the TPM counter is a free-running counter then the update is made when the TPM counter changes
from 0xFFFE to 0xFFFF.
16.4.2.4
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
while 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)
period = 2 x (TPMxMODH:TPMxMODL); TPMxMODH:TPMxMODL=0x0001-0x7FFF
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 (non-zero)
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 you
do not need to generate 100% duty cycle). This is not a significant limitation. The resulting period would
be 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.
The output compare value in the TPM channel registers (times 2) determines the pulse width (duty cycle)
of the CPWM signal (Figure 16-16). If ELSnA=0, a compare occurred while counting up forces the
CPWM output signal low and a compare occurred 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
OUTPUT
COUNT=
COMPARE
TPMxMODH:TPMxMODL (COUNT DOWN)
OUTPUT
COMPARE
(COUNT UP)
COUNT=
TPMxMODH:TPMxMODL
TPMxCHn
PULSE WIDTH
2 x TPMxCnVH:TPMxCnVL
PERIOD
2 x TPMxMODH:TPMxMODL
Figure 16-16. 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.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
287
Input capture, output compare, and edge-aligned PWM functions do not make sense when the counter is
operating in up/down counting mode so this implies that all active channels within a TPM must be used in
CPWM mode when CPWMS=1.
The TPM may be used in an 8-bit MCU. 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.
In center-aligned PWM mode, the TPMxCnVH:L registers are updated with the value of their write buffer
according to the value of CLKSB:CLKSA bits, so:
• If (CLKSB:CLKSA = 0:0), the registers are updated when the second byte is written
• If (CLKSB:CLKSA not = 0:0), the registers are updated after the both bytes were written, and the
TPM counter changes from (TPMxMODH:TPMxMODL - 1) to (TPMxMODH:TPMxMODL). If
the TPM counter is a free-running counter, the update is made when the TPM counter changes from
0xFFFE to 0xFFFF.
When TPMxCNTH:TPMxCNTL=TPMxMODH:TPMxMODL, the TPM can optionally generate a TOF
interrupt (at the end of this count).
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.
16.5
16.5.1
Reset Overview
General
The TPM is reset whenever any MCU reset occurs.
16.5.2
Description of Reset Operation
Reset clears the TPMxSC register which disables clocks to the TPM and disables timer overflow interrupts
(TOIE=0). CPWMS, MSnB, MSnA, ELSnB, and ELSnA are all cleared which configures all TPM
channels for input-capture operation with the associated pins disconnected from I/O pin logic (so all MCU
pins related to the TPM revert to general purpose I/O pins).
16.6
16.6.1
Interrupts
General
The TPM generates an optional interrupt for the main counter overflow and an interrupt for each channel.
The meaning of channel interrupts depends on each channel’s mode of operation. 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.
MC9S08JM16 Series Data Sheet, Rev. 2
288
Freescale Semiconductor
All TPM interrupts are listed in Table 16-8 which shows the interrupt name, the name of any local enable
that can block the interrupt request from leaving the TPM and getting recognized by the separate interrupt
processing logic.
Table 16-8. Interrupt Summary
Interrupt
Local
Enable
Source
Description
TOF
TOIE
Counter overflow
Set each time the timer counter reaches its terminal
count (at transition to next count value which is
usually 0x0000)
CHnF
CHnIE
Channel event
An input capture or output compare event took
place on channel n
The TPM module will provide a high-true interrupt signal. Vectors and priorities are determined at chip
integration time in the interrupt module so refer to the user’s guide for the interrupt module or to the chip’s
complete documentation for details.
16.6.2
Description of Interrupt Operation
For each interrupt source in the TPM, a flag bit is set upon 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 determine 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 generate
whenever the associated interrupt flag equals one. The user’s software must perform a sequence of steps
to clear the interrupt flag before returning from the interrupt-service routine.
TPM interrupt flags are cleared by a two-step process including a read of the flag bit while it is set (1)
followed by a write of zero (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.
16.6.2.1
Timer Overflow Interrupt (TOF) Description
The meaning and details of operation for TOF interrupts varies slightly depending upon the mode of
operation of the TPM system (general purpose timing functions versus center-aligned PWM operation).
The flag is cleared by the two step sequence described above.
16.6.2.1.1
Normal Case
Normally TOF is set when the timer counter changes from 0xFFFF to 0x0000. When the TPM is not
configured for center-aligned PWM (CPWMS=0), TOF gets set when the timer counter changes from the
terminal count (the value in the modulo register) to 0x0000. This case corresponds to the normal meaning
of counter overflow.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
289
16.6.2.1.2
Center-Aligned PWM Case
When CPWMS=1, TOF gets set when the timer counter changes direction from up-counting to
down-counting at the end of the terminal count (the value in the modulo register). In this case the TOF
corresponds to the end of a PWM period.
16.6.2.2
Channel Event Interrupt Description
The meaning of channel interrupts depends on the channel’s current mode (input-capture, output-compare,
edge-aligned PWM, or center-aligned PWM).
16.6.2.2.1
Input Capture Events
When a channel is configured as an input capture channel, the ELSnB:ELSnA control bits select no edge
(off), rising edges, falling edges or any edge as the edge which triggers an input capture event. When the
selected edge is detected, the interrupt flag is set. The flag is cleared by the two-step sequence described
in Section 16.6.2, “Description of Interrupt Operation.”
16.6.2.2.2
Output Compare Events
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 two-step
sequence described Section 16.6.2, “Description of Interrupt Operation.”
16.6.2.2.3
PWM End-of-Duty-Cycle Events
For channels configured for PWM operation there are two possibilities. When the channel is configured
for edge-aligned PWM, the channel flag gets set when the timer counter matches the channel value register
which 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 period which are the times
when the timer counter matches the channel value register. The flag is cleared by the two-step sequence
described Section 16.6.2, “Description of Interrupt Operation.”
1. Write to TPMxCnTH:L registers (Section 16.3.2, “TPM-Counter Registers
(TPMxCNTH:TPMxCNTL)) [SE110-TPM case 7]
Any write to TPMxCNTH or TPMxCNTL registers in TPM v3 clears the TPM counter
(TPMxCNTH:L) and the prescaler counter. Instead, in the TPM v2 only the TPM counter is cleared
in this case.
2. Read of TPMxCNTH:L registers (Section 16.3.2, “TPM-Counter Registers
(TPMxCNTH:TPMxCNTL))
— In TPM v3, any read of TPMxCNTH:L registers during BDM mode returns the value of the
TPM counter that is frozen. In TPM v2, if only one byte of the TPMxCNTH:L registers was
read before the BDM mode became active, then any read of TPMxCNTH:L registers during
BDM mode returns the latched value of TPMxCNTH:L from the read buffer instead of the
frozen TPM counter value.
MC9S08JM16 Series Data Sheet, Rev. 2
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Freescale Semiconductor
— This read coherency mechanism is cleared in TPM v3 in BDM mode if there is a write to
TPMxSC, TPMxCNTH or TPMxCNTL. Instead, in these conditions the TPM v2 does not clear
this read coherency mechanism.
3. Read of TPMxCnVH:L registers (Section 16.3.5, “TPM Channel Value Registers
(TPMxCnVH:TPMxCnVL))
— In TPM v3, any read of TPMxCnVH:L registers during BDM mode returns the value of the
TPMxCnVH:L register. In TPM v2, if only one byte of the TPMxCnVH:L registers was read
before the BDM mode became active, then any read of TPMxCnVH:L registers during BDM
mode returns the latched value of TPMxCNTH:L from the read buffer instead of the value in
the TPMxCnVH:L registers.
— This read coherency mechanism is cleared in TPM v3 in BDM mode if there is a write to
TPMxCnSC. Instead, in this condition the TPM v2 does not clear this read coherency
mechanism.
4. Write to TPMxCnVH:L registers
— Input Capture Mode (Section 16.4.2.1, “Input Capture Mode)
In this mode the TPM v3 does not allow the writes to TPMxCnVH:L registers. Instead, the
TPM v2 allows these writes.
— Output Compare Mode (Section 16.4.2.2, “Output Compare Mode)
In this mode and if (CLKSB:CLKSA not = 0:0), the TPM v3 updates the TPMxCnVH:L
registers with the value of their write buffer at the next change of the TPM counter (end of the
prescaler counting) after the second byte is written. Instead, the TPM v2 always updates these
registers when their second byte is written.
— Edge-Aligned PWM (Section 16.4.2.3, “Edge-Aligned PWM Mode)
In this mode and if (CLKSB:CLKSA not = 00), the TPM v3 updates the TPMxCnVH:L
registers with the value of their write buffer after that the both bytes were written and when the
TPM counter changes from (TPMxMODH:L - 1) to (TPMxMODH:L). If the TPM counter is
a free-running counter, then this update is made when the TPM counter changes from $FFFE
to $FFFF. Instead, the TPM v2 makes this update after that the both bytes were written and
when the TPM counter changes from TPMxMODH:L to $0000.
— Center-Aligned PWM (Section 16.4.2.4, “Center-Aligned PWM Mode)
In this mode and if (CLKSB:CLKSA not = 00), the TPM v3 updates the TPMxCnVH:L
registers with the value of their write buffer after that the both bytes were written and when the
TPM counter changes from (TPMxMODH:L - 1) to (TPMxMODH:L). If the TPM counter is
a free-running counter, then this update is made when the TPM counter changes from $FFFE
to $FFFF. Instead, the TPM v2 makes this update after that the both bytes were written and
when the TPM counter changes from TPMxMODH:L to (TPMxMODH:L - 1).
5. Center-Aligned PWM (Section 16.4.2.4, “Center-Aligned PWM Mode)
— TPMxCnVH:L = TPMxMODH:L [SE110-TPM case 1]
In this case, the TPM v3 produces 100% duty cycle. Instead, the TPM v2 produces 0% duty
cycle.
— TPMxCnVH:L = (TPMxMODH:L - 1) [SE110-TPM case 2]
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
291
In this case, the TPM v3 produces almost 100% duty cycle. Instead, the TPM v2 produces 0%
duty cycle.
— TPMxCnVH:L is changed from 0x0000 to a non-zero value [SE110-TPM case 3 and 5]
In this case, the TPM v3 waits for the start of a new PWM period to begin using the new duty
cycle setting. Instead, the TPM v2 changes the channel output at the middle of the current
PWM period (when the count reaches 0x0000).
— TPMxCnVH:L is changed from a non-zero value to 0x0000 [SE110-TPM case 4]
In this case, the TPM v3 finishes the current PWM period using the old duty cycle setting.
Instead, the TPM v2 finishes the current PWM period using the new duty cycle setting.
6. Write to TPMxMODH:L registers in BDM mode (Section 16.3.3, “TPM Counter Modulo
Registers (TPMxMODH:TPMxMODL))
In the TPM v3 a write to TPMxSC register in BDM mode clears the write coherency mechanism
of TPMxMODH:L registers. Instead, in the TPM v2 this coherency mechanism is not cleared when
there is a write to TPMxSC register.
MC9S08JM16 Series Data Sheet, Rev. 2
292
Freescale Semiconductor
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
293
MC9S08JM16 Series Data Sheet, Rev. 2
294
Freescale Semiconductor
Chapter 17
Universal Serial Bus Device Controller (S08USBV1)
17.1
Introduction
This chapter describes an universal serial bus device controller (S08USBV1) module that is based on the
Universal Serial Bus Specification Rev 2.0. The USB bus is designed to replace existing bus interfaces
such as RS-232, PS/2, and IEEE 1284 for PC peripherals.
The S08USBV1 module provides a single-chip solution for full-speed (12 Mbps) USB device applications, and integrates the required transceiver with Serial Interface Engine (SIE), 3.3 V regulator, Endpoint
RAM and other control logics.
17.1.1
Clocking Requirements
The S08USBV1 requires two clock sources, the 24 MHz bus clock and a 48 MHz reference clock. The
48 MHz clock is sourced directly from MCGOUT. To achieve the 48 MHz clock rate, the MCG must be
configured properly for PLL engaged external (PEE) mode with an external crystal.
For USB operation, examples of MCG configuration using PEE mode include:
• 2 MHz crystal – RDIV = 000 and VDIV = 0110
• 4 MHz crystal – RDIV = 001 and VDIV = 0110
17.1.2
Current Consumption in USB Suspend
In USB suspend mode, the S08USBV1 current consumption is limited to 500 μA. When the USB device
goes into suspend mode, the firmware typically enters stop3 to meet the USB suspend requirements on
current consumption.
NOTE
Enabling LVD increases current consumption in stop3. Consequently, when
trying to satisfy USB suspend requirements, disabling LVD before entering
stop3.
17.1.3
3.3 V Regulator
If using an external 3.3 V regulator as an input to VUSB33 (only when USBVREN = 0), the supply voltage,
VDD, must not fall below the input voltage at the VUSB33 pin. If using the internal 3.3 V regulator
(USBVREN = 1), do not connect an external supply to the VUSB33 pin. In this case, VDD must fall between
3.9 V and 5.5 V for the internal 3.3 V regulator to operate correctly.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
295
Chapter 17 Universal Serial Bus Device Controller (S08USBV1)
Table 17-1. USBVREN Configuration
USBVREN
VDD Supply Voltage Range
3.3 V Regulator
0
External 3.3 V Regulator (as input to VUSB33 pin)
VUSB33 ≤ VDD Supply Voltage
1
Internal 3.3 V Regulator (no external supply connected to
VUSB33 pin)
3.9 V ≤ VDD Supply Voltage ≤ 5.5 V
MC9S08JM16 Series Data Sheet, Rev. 2
296
Freescale Semiconductor
Chapter 17 Universal Serial Bus Device Controller (S08USBV1)
IRQ/TPMCLK
USB SIE
CPU
HCS08 SYSTEM CONTROL
RESETS AND INTERRUPTS
MODES OF OPERATION
POWER MANAGEMENT
COP
IRQ
8-/16-BIT SERIAL PERIPHERAL
INTERFACE MODULE (SPI2)
SERIAL COMMUNICATIONS
VDDAD
IIC MODULE (IIC)
SDA
SCL
6
8-/16-BIT SERIAL PERIPHERAL
INTERFACE MODULE (SPI16)
ACMP+
ACMPO
PTE6/SPSCK1
MOSI1
PTE5/MOSI1
VSS
VUSB33
SYSTEM
VOLTAGE
REGULATOR
SERIAL COMMUNICATIONS
INTERFACE MODULE (SCI1)
2-CHANNEL TIMER/PWM
MODULE (TPM2)
REAL-TIME COUNTER
(RTC)
7-BIT KEYBOARD
INTERRUPT MODULE (KBI)
PORT E
TPM1CH0
TPM1CHx
2
PTE3/TPM1CH1
PTE2/TPM1CH0
RxD1
TxD1
PTE1/RxD1
PTE0/TxD1
TPMCLK
TPM2CH1
TPM2CH0
PTF6
PTF5/TPM2CH1
PTF4/TPM2CH0
KBIPx
USB 3.3 V VOLTAGE REGULATOR
PTE4/MISO1
TPMCLK
TPM1CH1
KBIPx
EXTAL
XTAL
PORT F
VDD
LOW-POWER OSCILLATOR
MODULE (TPM1)
PTD2/KBIP2/ACMPO
PTE7/SS1
SPSCK1
3
PTF1/TPM1CH3
PTF0/TPM1CH2
4
NOTES:
1. Port pins are software configurable with pullup device if input port.
2. Pin contains software configurable pullup/pulldown device if pullup 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 must not be driven above VDD.
4. Pin contains integrated pullup device.
5. When pin functions as KBI (KBIPEn = 1) and associated pin is configured to enable the
pullup device, KBEDGn can be used to reconfigure the pullup as a pulldown device.
PTG5/EXTAL
PORT G
VSSOSC
4-CHANNEL TIMER/PWM
PTC5/RxD2
PTC4
PTC3/TxD2
PTC2
PTD1/ADP9/ACMP–
PTD0/ADP8/ACMP+
MISO1
MULTI-PURPOSE CLOCK
GENERATOR (MCG)
PTB5/KBIP5/ADP5
PTB4/KBIP4/ADP4
PTB3/SS2/ADP3
PTB2/SPSCK2/ADP2
PTB1/MOSI2/ADP1
PTB0/MISO2/ADP0
PTD7
SS1
USER RAM (IN BYTES)
1024
PTA5,PTA0
2
ACMP–
ANALOG COMPARATOR
(ACMP)
2
PTC1/SDA
PTC0/SCL
PORT D
USER Flash (IN BYTES)
MC9S08JM16 = 16,384
MC9S08JM8 = 8,192
RxD2
TxD2
8-CHANNEL, 12-BIT
ANALOG-TO-DIGITAL
CONVERTER (ADC)
VSSAD
VREFL
VREFH
SS2
SPSCK2
MOSI2
MISO2
INTERFACE MODULE (SCI2)
LVD
PORT B
BDC
FULL SPEED
USB
USB ENDPOINT TRANSCEIVER
RAM
PORT C
RESET
PORT A
HCS08 CORE
BKGD/MS
USBDP
USBDN
On Chip ICE AND
DEBUG MODULE (DBG)
PTG4/XTAL
PTG3/KBIP7
PTG2/KBIP6
PTG1/KBIP1
PTG0/KBIP0
Figure 17-1. MC9S08JM16 Series Block Diagram Highlighting USB Blocks and Pins
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
297
Universal Serial Bus Device Controller (S08USBV1)
17.1.4
Features
Features of the USB module include:
• USB 2.0 compliant
— 12 Mbps full-speed (FS) data rate
— USB data control logic:
– Packet identification and decoding/generation
– CRC generation and checking
– NRZI (non-return-to-zero inverted) encoding/decoding
– Bit-stuffing
– Sync detection
– End-of-packet detection
• Seven USB endpoints
— Bidirectional endpoint 0
— Six unidirectional data endpoints configurable as interrupt, bulk, or isochronous
— Endpoints 5 and 6 support double-buffering
• USB RAM
— 256 bytes of buffer RAM shared between system and USB module
— RAM may be allocated as buffers for USB controller or extra system RAM resource
• USB reset options
— USB module reset generated by MCU
— Bus reset generated by the host, which triggers a CPU interrupt
• Suspend and resume operations with remote wakeup support
• Transceiver features
— Converts USB differential voltages to digital logic signal levels
• On-chip USB pullup resistor
• On-chip 3.3 V regulator
17.1.5
Modes of Operation
Table 17-2. Operating Modes
Mode
Description
Stop1
USB module is not functional. Before entering stop1, the internal USB voltage regulator and USB transceiver
enter shutdown mode; therefore, the USB voltage regulator and USB transceiver must be disabled by firmware.
Stop2
USB module is not functional. Before entering stop2, the internal USB voltage regulator and USB transceiver
enter shutdown mode; therefore, the USB voltage regulator and USB transceiver must be disabled by firmware.
MC9S08JM16 Series Data Sheet, Rev. 2
298
Freescale Semiconductor
Universal Serial Bus Device Controller (S08USBV1)
Table 17-2. Operating Modes (continued)
Mode
Description
Stop3
The USB module is optionally available in stop3.
A reduced current consumption mode may be required for USB suspend mode per USB Specification Rev. 2.0,
and stop3 mode is useful for achieving lower current consumption for the MCU and hence the overall USB
device. Before entering stop3 via firmware, the user must ensure that the device settings are configured for
stop3 to achieve USB suspend current consumption targets.
The USB module is notified about entering suspend mode when the SLEEPF flag is set; this occurs after the
USB bus is idle for 3 ms. The device USB suspend mode current consumption level requirements are defined
by the USB Specification Rev. 2.0 (500 μA for low-power and 2.5 mA for high-power with remote-wakeup
enabled).
If USBRESMEN in USBCTL0 is set, and a K-state (resume signaling) is detected on the USB bus, the LPRESF
bit in USBCTL0 will be set. This triggers an asynchronous interrupt that will wakeup the MCU from stop3 mode
and enable clocks to the USB module. The USBRESMEN bit must then be cleared immediately after stop3
recovery to clear the LPRESF flag bit.
Wait
17.1.6
USB module is operational.
Block Diagram
Figure 17-2 is a block diagram of the USB module.
48 MHz Reference Clock
24 MHz Clock (bus clk)
USB CONTROLLER
Serial Interface Engine
(SIE)
USB RAM
256 bytes
BVCI
Target
TX
Logic
XCVR
USBDP
USBDN
Protocol and Rate
Match
Buffer
Manager
VUSB33
RAM
Arbitration
SkyBlue Gasket
Peripheral Bus
To Interrupt Controller
Local Bus
IRQ
Enable
USBDP Pullup
BVCI
Initiator
RX
Logic
VREG
Figure 17-2. USB Module Block Diagram
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
299
Universal Serial Bus Device Controller (S08USBV1)
17.2
External Signal Description
The USB module requires both data and power pins. Table 17-3 describes each of the USB external pin
Table 17-3. USB External Pins
Name
Port
Direction
Positive USB differential signal
USBDP
I/O
Differential USB signaling.
High
impedance
Negative USB differential signal
USBDN
I/O
Differential USB signaling.
High
impedance
USB voltage regulator power pin
VUSB33
Power
17.2.1
Function
Reset State
3.3 V USB voltage regulator output
or 3.3 V USB transceiver/resistor
supply input.
—
USBDP
USBDP is the positive USB differential signal. In a USB peripheral application, connect an external
33 Ω ±1% resistor in series with this signal in order to meet the USB Specification Rev. 2.0 impedance
requirement.
17.2.2
USBDN
USBDN is the negative USB differential signal. In a USB peripheral application, connect an external
33 Ω ±1% resistor in series with this signal in order to meet the USB Specification, Rev. 2.0 impedance
requirement.
17.2.3
VUSB33
VUSB33 is connected to the on-chip 3.3 V voltage regulator (VREG). VUSB33 maintains an output voltage
of 3.3 V and can only source enough current for USB internal transceiver (XCVR) and USB pullup
resistor. If the VREG is disabled by software, the application must input an external 3.3 V power supply
to the USB module via VUSB33.
17.3
Register Definition
This section describes the memory map and control/status registers for the USB module.
MC9S08JM16 Series Data Sheet, Rev. 2
300
Freescale Semiconductor
Universal Serial Bus Device Controller (S08USBV1)
17.3.1
USB Control Register 0 (USBCTL0)
7
R
6
5
USBPU
USBRESMEN
0
0
0
4
3
LPRESF
0
2
1
0
0
USBVREN
USBPHYEN
W USBRESET
Reset
0
0
0
0
0
0
= Unimplemented or Reserved
Figure 17-3. USB Transceiver and Regulator Control Register 0 (USBCTL0)
Table 17-4. USBCTL0 Field Descriptions
Field
Description
7
USBRESET
USB Reset — This bit generates a hard reset of the USB module, USBPHYEN and USBVREGEN bits will also
be cleared. (need remember to restart USB Transceiver and USB voltage regulator).
When set to 1, this bit automatically clears when the reset occurs.
0 USB module normal operation
1 Returns the USB module to its reset state
6
USBPU
Pull Up Source — This bit determines the source of the pullup resistor on the USBDP line.
0 Internal USBDP pullup resistor is disabled; The application can use an external pullup resistor
1 Internal USBDP pullup resistor is enabled
5
USBRESMEN
USB Low-Power Resume Event Enable — This bit, when set, enables the USB module to send an
asynchronous wakeup interrupt to the MCU upon detection that the LPRESF bit has been set, indicating
a K-state on the USB bus. This bit must be set before entering low-power stop3 mode only after SLEEPF=1 (USB
is entering suspend mode). It must be cleared immediately after stop3 recovery in order to clear the Low-Power
Resume Flag.
0 USB asynchronous wakeup from suspend mode disabled
1 USB asynchronous wakeup from suspend mode enabled
4
LPRESF
Low-Power Resume Flag — This bit becomes set in USB suspend mode if USBRESMEN=1 and a K-state is
detected on the USB bus, indicating resume signaling while the device is in a low-power stop3 mode. This flag
bit will trigger an asynchronous interrupt, which will wake the device from stop3. Firmware must then clear the
USBRESMEN bit in order to clear the LPRESF bit.
0 No K-state detected on the USB bus while the device is in stop3 and the USB is suspended.
1 K-state detected on the USB bus when USBRESMEN=1, the device is in stop3, and the USB is suspended.
2
USBVREN
0
USBPHYEN
17.3.2
USB Voltage Regulator Enable — This bit enables the on-chip 3.3 V USB voltage regulator.
0 On-chip USB voltage regulator is disabled (OFF MODE)
1 On-chip USB voltage regulator is enabled for active or standby mode
USB Transceiver Enable — When the USB Transceiver (XCVR) is disabled, USBDP and USBDN are hi-Z. It is
recommended that the XCVR be enabled before setting the USBEN bit in the CTL register. The firmware must
ensure that the XCVR remains enabled when entering USB SUSPEND mode.
0 On-chip XCVR is disabled
1 On-chip XCVR is enabled
Peripheral ID Register (PERID)
The PERID reads back the value of 0x04. This value is defined for the USB module peripheral.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
301
Universal Serial Bus Device Controller (S08USBV1)
R
7
6
5
4
3
2
1
0
0
0
ID5
ID4
ID3
ID2
ID1
ID0
0
0
0
0
0
1
0
0
W
Reset
= Unimplemented or Reserved
Figure 17-4. Peripheral ID Register (PERID)
Table 17-5. PERID Field Descriptions
Field
5:0
ID[5:0]
17.3.3
Description
Peripheral Configuration Number —This number is set to 0x04 and indicates that the peripheral is the
full-speed USB module.
Peripheral ID Complement Register (IDCOMP)
The IDCOMP reads back the complement of the peripheral ID register. For the USB module peripheral this will be
0xFB.
R
7
6
5
4
3
2
1
0
1
1
NID5
NID4
NID3
NID2
NID1
NID0
1
1
1
1
1
0
1
1
W
Reset
= Unimplemented or Reserved
Figure 17-5. Peripheral ID Complement Register (IDCOMP)
Table 17-6. IDCOMP Field Descriptions
Field
5:0
NID[5:0]
17.3.4
Description
Compliment ID Number — One’s complement version of ID[5:0].
Peripheral Revision Register (REV)
The REV reads back the value of the USB peripheral revision.
R
7
6
5
4
3
2
1
0
REV7
REV6
REV5
REV4
REV3
REV2
REV1
REV0
0
0
0
0
0
0
0
0
W
Reset
= Unimplemented or Reserved
Figure 17-6. Peripheral Revision Register (REV)
MC9S08JM16 Series Data Sheet, Rev. 2
302
Freescale Semiconductor
Universal Serial Bus Device Controller (S08USBV1)
Table 17-7. REV Field Descriptions
Field
8–0
REV[7:0]
17.3.5
Description
Revision — Revision number of the USB module.
Interrupt Status Register (INTSTAT)
The INTSTAT contains bits for each of the interrupt source within the USB module. Each of these bits is
qualified with its respective interrupt enable bits (see the interrupt enable register). All bits of the register
are logically OR'ed together to form a single interrupt source for the microcontroller. Once an interrupt bit
has been set, it may only be cleared by writing a 1 to the respective interrupt bit. This register will contain
the value of 0x00 after a reset.
7
R
6
0
STALLF
5
4
3
2
1
0
RESUMEF
SLEEPF
TOKDNEF
SOFTOKF
ERRORF
USBRSTF
0
0
0
0
0
0
W
Reset
0
0
= Unimplemented or Reserved
Figure 17-8. Interrupt Status Register (INTSTAT)
Table 17-9. INTSTAT Field Descriptions
Field
Description
7
STALLF
Stall Flag — The stall interrupt is used in device mode. In device mode the stall flag is asserted when a STALL
handshake is sent by the serial interface engine (SIE).
0 A STALL handshake has not been sent
1 A STALL handshake has been sent
5
RESUMEF
Resume Flag — This bit is set 2.5 μs after clocks to the USB module have restarted following resume signaling.
It can be used to indicate remote wakeup signaling on the USB bus. This interrupt is enabled only when the
USB module is about to enter suspend mode (usually when SLEEPF interrupt detected).
0 No RESUME observed
1 RESUME detected (K-state is observed on the USBDP/USBDN signals for 2.5 μs)
4
SLEEPF
Sleep Flag — This bit is set if the USB module has detected a constant idle on the USB bus for 3 ms, indicating
that the USB module will go into suspend mode. The sleep timer is reset by activity on the USB bus.
0 No constant idle state of 3 ms has been detected on the USB bus
1 A constant idle state of 3 ms has been detected on the USB bus
3
TOKDNEF
Token Complete Flag — This bit is set when the current transaction is completed. The firmware must
immediately read the STAT register to determine the endpoint and BD information. Clearing this bit (by setting it
to 1) causes the STAT register to be cleared or the STAT FIFO holding register to be loaded into the STAT register.
0 No tokens being processed are complete
1 Current token being processed is complete
2
SOFTOKF
SOF Token Flag — This bit is set if the USB module has received a start of frame (SOF) token.
0 The USB module has not received an SOF token
1 The USB module has received an SOF token
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
303
Universal Serial Bus Device Controller (S08USBV1)
Table 17-9. INTSTAT Field Descriptions (continued)
Field
Description
1
ERRORF
Error Flag — This bit is set when any of the error conditions within the ERRSTAT register has occurred. The
firmware must then read the ERRSTAT register to determine the source of the error.
0 No error conditions within the ERRSTAT register have been detected
1 Error conditions within the ERRSTAT register have been detected
0
USBRSTF
USB Reset Flag —This bit is set when the USB module has decoded a valid USB reset. When asserted, this bit
will inform the MCU to automatically write 0x00 to the address register and to enable endpoint 0. USBRSTF is
set once a USB reset has been detected for 2.5 μs. It will not be asserted again until the USB reset condition has
been removed, and then reasserted.
0 No USB reset observed
1 USB reset detected
17.3.6
Interrupt Enable Register (INTENB)
The INTENB contains enabling bits for each of the interrupt sources within the USB module. Setting any of these
bits will enable the respective interrupt source in the INTSTAT register. This register will contain the value of 0x00
after a reset, i.e. all interrupts disabled.
7
R
STALL
6
0
5
4
3
2
1
0
RESUME
SLEEP
TOKDNE
SOFTOK
ERROR
USBRST
0
0
0
0
0
0
W
Reset
0
0
Figure 17-9. Interrupt Enable Register (INTENB)
Table 17-10. INTENB Field Descriptions
Field
7
STALL
5
RESUME
4
SLEEP
Description
STALL Interrupt Enable — Setting this bit will enable STALL interrupts.
0 Interrupt disabled
1 Interrupt enabled
RESUME Interrupt Enable — Setting this bit will enable RESUME interrupts.
0 Interrupt disabled
1 Interrupt enabled
SLEEP Interrupt Enable — Setting this bit will enable SLEEP interrupts.
0 Interrupt disabled
1 Interrupt enabled
3
TOKDNE
TOKDNE Interrupt Enable — Setting this bit will enable TOKDNE interrupts.
0 Interrupt disabled
1 Interrupt enabled
2
SOFTOK
SOFTOK Interrupt Enable — Setting this bit will enable SOFTOK interrupts.
0 Interrupt disabled
1 Interrupt enabled
MC9S08JM16 Series Data Sheet, Rev. 2
304
Freescale Semiconductor
Universal Serial Bus Device Controller (S08USBV1)
Table 17-10. INTENB Field Descriptions (continued)
Field
Description
1
ERROR
ERROR Interrupt Enable — Setting this bit will enable ERROR interrupts.
0 Interrupt disabled
1 Interrupt enabled
0
USBRST
USBRST Interrupt Enable — Setting this bit will enable USBRST interrupts.
0 Interrupt disabled
1 Interrupt enabled
17.3.7
Error Interrupt Status Register (ERRSTAT)
The ERRSTAT contains bits for each of the error sources within the USB module. Each of these bits
corresponds to its respective error enable bit (See Section 17.3.8, “Error Interrupt Enable Register
(ERRENB)”.) The result is OR'ed together and sent to the ERROR bit of the INTSTAT register. Once an
interrupt bit has been set, it may only be cleared by writing a 1 to the corresponding flag bit. Each bit is
set as soon as the error condition is detected. Thus, the interrupt will typically not correspond with the end
of a token being processed. This register will contain the value of 0x00 after reset.
7
6
5
4
3
2
1
0
BTSERRF
Reserved
BUFERRF
BTOERRF
DFN8F
CRC16F
CRC5F
PIDERRF
0
0
0
0
0
0
0
0
R
W
Reset
Figure 17-10. Error Interrupt Status Register (ERRSTAT)
Table 17-11. ERRSTAT Field Descriptions
Field
Description
7
BTSERRF
Bit Stuff Error Flag — A bit stuff error has been detected. If set, the corresponding packet will be rejected due
to a bit stuff error.
0 No bit stuff error detected
1 Bit stuff error flag set
5
BUFERRF
Buffer Error Flag — This bit is set if the USB module has requested a memory access to read a new BD but
has not been given the bus before the USB module needs to receive or transmit data. If processing a TX (IN
endpoint) transfer, this would cause a transmit data underflow condition. Or if processing an Rx (OUT endpoint)
transfer, this would cause a receive data overflow condition. This bit is also set if a data packet to or from the host
is larger than the buffer size that is allocated in the BD. In this case the data packet is truncated as it is put into
buffer memory.
0 No buffer error detected
1 A buffer error has occurred
4
BTOERRF
Bus Turnaround Error Timeout Flag — This bit is set if a bus turnaround timeout error has occurred. The USB
module uses a bus turnaround timer to keep track of the amount of time elapsed between the token and data
phases of a SETUP or OUT TOKEN or the data and handshake phases of an IN TOKEN. If more than 16-bit
times are counted from the previous EOP before a transition from IDLE, a bus turnaround timeout error will occur.
0 No bus turnaround timeout error has been detected
1 A bus turnaround timeout error has occurred
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
305
Universal Serial Bus Device Controller (S08USBV1)
Table 17-11. ERRSTAT Field Descriptions (continued)
Field
Description
3
DFN8F
Data Field Error Flag — The data field received was not an interval of 8 bits. The USB Specification specifies
that the data field must be an integer number of bytes. If the data field was not an integer number of bytes, this
bit will be set.
0 The data field was an integer number of bytes
1 The data field was not an integer number of bytes
2
CRC16F
CRC16 Error Flag — The CRC16 failed. If set, the data packet was rejected due to a CRC16 error.
0 No CRC16 error detected
1 CRC16 error detected
1
CRC5F
CRC5 Error Flag — This bit will detect a CRC5 error in the token packets generated by the host. If set, the
token packet was rejected due to a CRC5 error.
0 No CRC5 error detected
1 CRC5 error detected, and the token packet was rejected.
0
PIDERRF
17.3.8
PID Error Flag — The PID check failed.
0 No PID check error detected
1 PID check error detected
Error Interrupt Enable Register (ERRENB)
7
R
6
0
BTSERR
5
4
3
2
1
0
BUFERR
BTOERR
DFN8
CRC16
CRC5
PIDERR
0
0
0
0
0
0
W
Reset
0
0
Figure 17-11. Error Interrupt Enable Register (ERRENB)
Table 17-12. ERRSTAT Field Descriptions
Field
Description
7
BTSERR
BTSERR Interrupt Enable — Setting this bit will enable BTSERR interrupts.
0 Interrupt disabled
1 Interrupt enabled
5
BUFERR
BUFERR Interrupt Enable — Setting this bit will enable BUFERR interrupts.
0 Interrupt disabled
1 Interrupt enabled
4
BTOERR
BTOERR Interrupt Enable — Setting this bit will enable BTOERR interrupts.
0 Interrupt disabled
1 Interrupt enabled
3
DFN8
2
CRC16
DFN8 Interrupt Enable — Setting this bit will enable DFN8 interrupts.
0 Interrupt disabled
1 Interrupt enabled
CRC16 Interrupt Enable — Setting this bit will enable CRC16 interrupts.
0 Interrupt disabled
1 Interrupt enabled
MC9S08JM16 Series Data Sheet, Rev. 2
306
Freescale Semiconductor
Universal Serial Bus Device Controller (S08USBV1)
Table 17-12. ERRSTAT Field Descriptions (continued)
Field
1
CRC5
0
PIDERR
17.3.9
Description
CRC5 Interrupt Enable — Setting this bit will enable CRC5 interrupts.
0 Interrupt disabled
1 Interrupt enabled
PIDERR Interrupt Enable — Setting this bit will enable PIDERR interrupts.
0 Interrupt disabled
1 Interrupt enabled
Status Register (STAT)
The STAT reports the transaction status within the USB module. When the MCU receives a TOKDNE
interrupt, the STAT is read to determine the status of the previous endpoint communication. The data in
the status register is valid only when the TOKDNEF interrupt flag is asserted. The STAT register is actually
a read window into a status FIFO maintained by the USB module. When the USB module uses a BD, it
updates the status register. If another USB transaction is performed before the TOKDNE interrupt is
serviced, the USB module will store the status of the next transaction in the STAT FIFO. Thus, the STAT
register is actually a four byte FIFO which allows the microcontroller to process one transaction while the
serial interface engine (SIE) is processing the next. Clearing the TOKDNEF bit in the INTSTAT register
causes the SIE to update the STAT register with the contents of the next STAT value. If the next data in the
STAT FIFO holding register is valid, the SIE will immediately reassert the TOKDNE interrupt.
7
6
R
5
4
ENDP[3:0]
3
2
1
0
IN
ODD
0
0
0
0
0
0
W
Reset
0
0
0
0
= Unimplemented or Reserved
Figure 17-12. Status Register (STAT)
Table 17-13. STAT Field Descriptions
Field
Description
7–4
ENDP[3:0]
Endpoint Number — These four bits encode the endpoint address that received or transmitted the previous
token. This allows the microcontroller to determine which BDT entry was updated by the last USB transaction.
0000 Endpoint 0
0001 Endpoint 1
0010 Endpoint 2
0011 Endpoint 3
0100 Endpoint 4
0101 Endpoint 5
0110 Endpoint 6
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
307
Universal Serial Bus Device Controller (S08USBV1)
Table 17-13. STAT Field Descriptions (continued)
Field
3
IN
2
ODD
Description
In/Out Transaction — This bit indicates whether the last BDT updated was for a transmit (IN) transfer or a
receive (OUT) data transfer.
0 Last transaction was a receive (OUT) data transfer
1 Last BDT updated was for transmit (IN) transfer
Odd/Even Transaction —This bit indicates whether the last buffer descriptor updated was in the odd bank of
the BDT or the even bank of the BDT, See earlier section for more information on BDT address generation.
0 Last buffer descriptor updated was in the EVEN bank
1 Last buffer descriptor updated was in the ODD bank
17.3.10 Control Register (CTL)
The CTL provides various control and configuration information for the USB module.
7
6
5
4
3
2
1
0
CRESUME
ODDRST
USBEN
0
0
0
R
TSUSPEND
W
Reset
0
0
0
0
0
Figure 17-13. Control Register (CTL)
Table 17-14. CTL Field Descriptions
Field
Description
5
TSUSPEND
Transaction Suspend — This bit is set by the serial interface engine (SIE) when a setup token is received,
allowing software to dequeue any pending packet transactions in the BDT before resuming token processing.
The TSUSPEND bit informs the processor that the SIE has disabled packet transmission and reception.
Clearing this bit allows the SIE to continue token processing.
0 Allows the SIE to continue token processing
1 Set by the SIE when a setup token is received; SIE has disabled packet transmission and reception.
2
CRESUME
Resume Signaling — Setting this bit will allow the USB module to execute resume signaling. This will allow
the USB module to perform remote wakeup. Software must set CRESUME to 1 for the amount of time
required by the USB Specification Rev. 2.0 and then clear it to 0.
0 Do not execute remote wakeup
1 Execute resume signaling — remote wakeup
1
ODDRST
Odd Reset — Setting this bit will reset all the buffer descriptor ODD ping-pong bits to 0 which will then specify
the EVEN descriptor bank. This bit is used with double-buffered endpoints 5 and 6. This bit has no effect on
endpoints 0 through 4.
0 Do not reset
1 Reset all the buffer descriptor ODD ping/pong bits to 0 which will then specify the EVEN descriptor bank
0
USBEN
USB Enable Setting this bit will enable the USB module to operate. Setting this bit causes the SIE to reset
all of its ODD bits to the BDTs. Thus, setting this bit will reset much of the logic in the SIE.
0 Disable the USB module
1 Enable the USB module for operation, will not affect Transceiver and VREG.
MC9S08JM16 Series Data Sheet, Rev. 2
308
Freescale Semiconductor
Universal Serial Bus Device Controller (S08USBV1)
17.3.11 Address Register (ADDR)
The ADDR register contains the unique 7-bit address the device will be recognized as through USB. The
register is reset to 0x00 after the reset input has gone active or the USB module has decoded USB reset
signaling. That will initialize the address register to decode address 0x00 as required by the USB
specification. Firmware will change the value when it processes a SET_ADDRESS request.
7
R
6
5
4
3
2
1
0
ADDR6
ADDR5
ADDR4
ADDR3
ADDR2
ADDR1
ADDR0
0
0
0
0
0
0
0
0
W
Reset
0
Figure 17-14. Address Register (ADDR)
Table 17-15. ADDR Field Descriptions
Field
6–0
ADDR[6:0]
Description
USB Address — This 7-bit value defines the USB address that the USB module will decode
17.3.12 Frame Number Register (FRMNUML, FRMNUMH)
The frame number registers contains the 11-bit frame number. The frame number registers require two
8-bit registers to implement. The low order byte is contained in FRMNUML, and the high order byte is
contained in FRMNUMH. These registers are updated with the current frame number whenever a SOF
TOKEN is received.
R
7
6
5
4
3
2
1
0
FRM7
FRM6
FRM5
FRM4
FRM3
FRM2
FRM1
FRM0
0
0
0
0
0
0
0
0
W
Reset
= Unimplemented or Reserved
Figure 17-15. Frame Number Register Low (FRMNUML)
Table 17-16. FRMNUML Field Descriptions
Field
7–0
FRM[7:0]
Description
Frame Number — These bits represent the low order bits of the 11 bit frame number.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
309
Universal Serial Bus Device Controller (S08USBV1)
R
7
6
5
4
3
2
1
0
0
0
0
0
0
FRM10
FRM9
FRM8
0
0
0
0
0
0
0
0
W
Reset
= Unimplemented or Reserved
Figure 17-16. Frame Number Register High (FRMNUMH)
Table 17-17. FRMNUMH Field Descriptions
Field
2–0
FRM[10:8]
Description
Frame Number — These bits represent the high order bits of the 11-bit frame number.
17.3.13 Endpoint Control Register (EPCTLn, n=0-6)
The endpoint control registers contains the endpoint control bits (EPCTLDIS, EPRXEN, EPTXEN, and
EPHSHK) for each endpoint available within the USB module for a decoded address. These four bits
define all of the control necessary for any one endpoint. The formats for these registers are shown in the
tables below. Endpoint 0 (ENDP0) is associated with control pipe 0 which is required by the USB for all
functions. Therefore, after a USBRST interrupt has been received, the microcontroller must set EPCTL0
to contain 0x0D.
R
7
6
0
0
5
4
3
2
1
0
0
EPCTLDIS
EPRXEN
EPTXEN
EPSTALL
EPHSHK
0
0
0
0
0
0
W
Reset
(EP0-6)
0
0
= Unimplemented or Reserved
Figure 17-17. Endpoint Control Register (EPCTLn)
Table 17-18. EPCTLn Field Descriptions
Field
4
EPCTLDIS
Description
Endpoint Control — This bit defines if an endpoint is enabled and the direction of the endpoint. The
endpoint enable/direction control is defined in Table 17-19.
3
EPRXEN
Endpoint Rx Enable — This bit defines if an endpoint is enabled for OUT transfers. The endpoint
enable/direction control is defined in Table 17-19.
2
EPTXEN
Endpoint Tx Enable — This bit defines if an endpoint is enabled for IN transfers. The endpoint
enable/direction control is defined in Table 17-19.
MC9S08JM16 Series Data Sheet, Rev. 2
310
Freescale Semiconductor
Universal Serial Bus Device Controller (S08USBV1)
Table 17-18. EPCTLn Field Descriptions (continued)
Field
Description
1
EPSTALL
Endpoint Stall — When set, this bit indicates that the endpoint is stalled. This bit has priority over all other
control bits in the endpoint control register, but is only valid if EPTXEN=1 or EPRXEN=1. Any access to this
endpoint will cause the USB module to return a STALL handshake. Once an endpoint is stalled it requires
intervention from the host controller.
0 Endpoint n is not stalled
1 Endpoint n is stalled
0
EPHSHK
Endpoint Handshake — This bit determines if the endpoint will perform handshaking during a transaction
to the endpoint. This bit will generally be set unless the endpoint is isochronous.
0 No handshaking performed during a transaction to this endpoint (usually for isochronous endpoints)
1 Handshaking performed during a transaction to this endpoint
Table 17-19. Endpoint Enable/Direction Control
Bit Name
Endpoint Enable/Direction Control
4
EPCTLDIS
3
EPRXEN
2
EPTXEN
X
0
0
Disable endpoint
X
0
1
Enable endpoint for IN(TX) transfers only
X
1
0
Enable endpoint for OUT(RX) transfers only
0
1
1
Enable endpoint for IN, OUT and SETUP transfers.
1
1
1
RESERVED
17.4
Functional Description
This section describes the functional behavior of the USB module. It documents data packet processing
for endpoint 0 and data endpoints, USB suspend and resume states, SOF token processing, reset conditions
and interrupts.
17.4.1
Block Descriptions
Figure 17-2 is the block diagram. The module’s sub-blocks and external signals are described in the
following sections. The module involves several major blocks — USB transceiver (XCVR), USB serial
interface engine (SIE), a 3.3 V regulator (VREG), endpoint buffer manager, shared RAM arbitration, USB
RAM and the SkyBlue gasket.
17.4.1.1
USB Serial Interface Engine (SIE)
The SIE is composed of two major functions: TX Logic and RX Logic. These major functions are
described below in more detail. The TX and RX logic are connected by a USB protocol engine which
manages packet flow to and from the USB module. The SIE is connected to the rest of the system via
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
311
Universal Serial Bus Device Controller (S08USBV1)
internal basic virtual component interface (BVCI) compliant target and initiator buses. The BVCI target
interface is used to configure the USB SIE and to provide status and interrupts to CPU. The BVCI initiator
interface provides the integrated DMA controller access to the buffer descriptor table (BDT), and transfers
USB data to or from USB RAM memory.
17.4.1.1.1
Serial Interface Engine (SIE) Transmitter Logic
The SIE transmitter logic has two primary functions. The first is to format the USB data packets that have
been stored in the endpoint buffers. The second is to transmit data packets via the USB transceiver.
All of the necessary USB data formatting is performed by the SIE transmitter logic, including:
• NRZI encoding
• bit-stuffing
• CRC computation
• addition of the SYNC field
• addition of the End-of-packet (EOP)
The CPU typically places data in the endpoint buffers as part of the application. When the buffer is
configured as an IN buffer and the USB host requests a packet, the SIE responds with a properly formatted
data packet.
The transmitter logic is also used to generate responses to packets received from the USB host. When a
properly formatted packet is received from the USB host, the transmitter logic responds with the
appropriate ACK, NAK or STALL handshake.
When the SIE transmitter logic is transmitting data from the buffer space for a particular endpoint, CPU
access to that endpoint buffer space is not recommended.
17.4.1.1.2
Serial Interface Engine (SIE) Receiver Logic
The SIE receiver logic receives USB data and stores USB packets in USB RAM for processing by the CPU
and the application software. Serial data from the transceiver is converted to a byte-wide parallel data
stream, checked for proper packet framing, and stored in the USB RAM memory.
Received bitstream processing includes the following operations:
• decodes an NRZI USB serial data stream
• Sync detection
• Bit-stuff removal (and error detection)
• End-of-packet (EOP) detection
• CRC validation
• PID check
• other USB protocol layer checks.
The SIE receiver logic provides error detection including:
• Bad CRC
• Timeout detection for EOP
MC9S08JM16 Series Data Sheet, Rev. 2
312
Freescale Semiconductor
Universal Serial Bus Device Controller (S08USBV1)
•
Bit stuffing violation
If a properly formatted packet is received, the receiver logic initiates a handshake response to the host. If
the packet is not decoded correctly due to bit stuff violation, CRC error or other packet level problem, the
receiver ignores it. The USB host will eventually time-out waiting for a response, and retransmit the
packet.
When the SIE receiver logic is receiving data in the buffer space for a particular endpoint, CPU access to
that buffer space is not recommended.
17.4.1.2
17.4.1.2.1
MCU/Memory Interfaces
SkyBlue Gasket
The SkyBlue gasket connects the USB module to the SoC internal peripheral bus. The gasket maps
accesses to the endpoint buffer descriptors or the endpoint buffers into the shared RAM block, and it also
maps accesses to the peripherals register set into the serial interface engine (SIE) register space. The
SkyBlue gasket interface includes registers to control the USB transceiver and voltage regulator.
17.4.1.2.2
Endpoint Buffer Manager
Each endpoint supported by the USB device transmits data to and from buffers stored in the shared buffer
memory. The serial interface engine (SIE) uses a table of descriptors, the Buffer Descriptor Table (BDT),
which is also stored in the USB RAM to describe the characteristics of each endpoint. The endpoint buffer
manager is responsible for mapping requests to access endpoint buffer descriptors into physical addresses
within the USB RAM block.
17.4.1.2.3
RAM Arbitration
The arbitration block allows access to the USB RAM block from the SkyBlue gasket block and from the
SIE.
17.4.1.3
USB RAM
The USB module includes 256 bytes of high speed RAM, accessible by the USB serial interface engine
(SIE) and the CPU. The USB RAM runs at twice the speed of the bus clock to allow interleaved
non-blocked access by the CPU and SIE. The USB RAM is used for storage of the buffer descriptor table
(BDT) and endpoint buffers. USB RAM that is not allocated for the BDT and endpoint buffers can be used
as system memory. If the USB module is not enabled, then the entire USB RAM may be used as unsecured
system memory.
17.4.1.4
USB Transceiver (XCVR)
The USB transceiver is electrically compliant to the Universal Serial Bus Specification 2.0. This block
provides the necessary 2-wire differential NRZI signaling for USB communication. The transceiver is
on-chip to provide a cost effective single chip USB peripheral solution.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
313
Universal Serial Bus Device Controller (S08USBV1)
17.4.1.5
USB On-Chip Voltage Regulator (VREG)
The on-chip 3.3 V regulator provides a stable power source to power the USB internal transceiver and
provide for the termination of an internal or external pullup resistor. When the on-chip regulator is enabled,
it requires a voltage supply input in the range from 3.9 V to 5.5 V, and the voltage regulator output will be
in the range of 3.0 V to 3.6 V.
With a dedicated on-chip USB 3.3 V regulator and a separate power supply for the MCU, the MCU and
USB can operate at different voltages (See the USB electricals regarding the USB voltage regulator
electrical characteristics). When the on-chip 3.3 V regulator is disabled, a 3.3 V source must be provided
through the VUSB33 pin to power the USB transceiver. In this case, the power supply voltage to the MCU
must not fall below the input voltage at the VUSB33 pin.
The 3.3 V regulator has 3 modes including:
• Active mode — This mode is entered when USB is active. Current requirement is sufficient to
power the transceiver and the USBDP pullup resistor.
• Standby — The voltage regulator standby mode is entered automatically when the USB device is
in suspend mode. When the USB device is forced into suspend mode by the USB bus, the firmware
must configure the MCU for stop3 mode. In standby mode, the requirement is to maintain the
USBDP pin voltage at 3.0 V to 3.6 V, with a 900 Ω (worst-case) pullup.
• Power off — This mode is entered anytime when stop2 or stop1 is entered or when the voltage
regulator is disabled.
17.4.1.6
USB On-Chip USBDP Pullup Resistor
The pullup resistor on the USBDP line required for full-speed operation by the USB Specification Rev. 2.0
can be internal or external to the MCU, depending on the application requirements. An on-chip pullup
resistor, implemented as specified in the USB 2.0 resistor ECN, is optionally available via firmware
configuration. Alternatively, this on-chip pullup resistor can be disabled, and the USB module can be
configured to use an external pullup resistor for the USBDP line instead. If using an external pullup resistor
on the USBDP line, the resistor must comply with the requirements in the USB 2.0 resistor ECN found at
http://www.usb.org.
The USBPU bit in the USBCTL0 register can be used to indicate if the pullup resistor is internal or external
to the MCU. If USBPU is clear, the internal pullup resistor on USBDP is disabled, and an external USBDP
pullup can be used. When using an external USBDP pullup, if the voltage regulator is enabled, the VUSB33
voltage output can be used with the USBDP pullup. While the use of the internal USBDP pullup resistor
is generally recommended, the figure below shows the USBDP pullup resistor configuration for a USB
device using an external resistor tied to VUSB33.
MC9S08JM16 Series Data Sheet, Rev. 2
314
Freescale Semiconductor
Universal Serial Bus Device Controller (S08USBV1)
USB DEVICE
3.3 V
VUSB33
RDPPU
USBDP
USBDN
Figure 17-18. USBDP/USBDN Pullup Resistor Configuration for USB module
17.4.1.7
USB Powering and USBDP Pullup Enable Options
The USB module provides a single-chip solution for USB device applications that are self-powered or
bus-powered. The USB device needs to know when it has a valid USB connection in order to enable or
disable the pullup resistor on the USBDP line. For the USB module on this device, the pullup on USBDP
is only applied when a valid VBUS connection is sensed, as required by the USB specification.
In bus-powered applications, system power must be derived from VBUS. Because VBUS is only available
when a valid USB connection from host to device is made, the VBUS sensing is built-in, and the USBDP
pullup can be enabled accordingly.
With self-powered applications, determining when a valid USB connection is made is different from that
of bus-powered applications. In self-powered applications, VBUS sensing must be built into the
application. For instance, a KBI pin interrupt can be utilized (if available). When a valid VBUS connection
is made, the KBI interrupt can notify the application that a valid USB connection is available, and the
internal pullup resistor can be enabled using the USBPU bit. If an external pullup resistor is used instead
of the internal one, the VBUS sensing mechanism must be included in the system design.
Table 17-20 summarizes the differences in enabling the USBDP pullup for different USB power modes.
Table 17-20. USBDP Pullup Enable for Different USB Power Modes
Power
Bus Power
(Built-in VBUS sense)
Self Power
(Build VBUS sense into application)
USBDP Pullup
Pullup Enable
Internal
Set USBPU bit
External
Build into application
Internal
Set USBPU bit
External
Build into application
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
315
Universal Serial Bus Device Controller (S08USBV1)
17.4.2
Buffer Descriptor Table (BDT)
To efficiently manage USB endpoint communications, the USB module implements a buffer descriptor
table (BDT) comprised of buffer descriptors (BD) in the local USB RAM. The BD entries provide status
or control information for a corresponding endpoint. The BD entries also provide an address to the
endpoint’s buffer. A single BD for an endpoint direction requires 3-bytes. A detailed description of the
BDT format is provided in the next sections.
The software API intelligently manages buffers for the USB module by updating the BDT when needed.
This allows the USB module to efficiently handle data transmission and reception, while the
microcontroller performs communication overhead processing and other function dependent applications.
Because the buffers are shared between the microcontroller and the USB module, a simple semaphore
mechanism is used to distinguish who is allowed to update the BDT and buffers in buffer memory. A
semaphore bit, the OWN bit, is cleared to 0 when the BD entry is owned by the microcontroller. The
microcontroller is allowed read and write access to the BD entry and the data buffer when the OWN bit is
0. When the OWN bit is set to 1, the BD entry and the data buffer are owned by the USB module. The USB
module now has full read and write access and the microcontroller must not modify the BD or its
corresponding data buffer.
17.4.2.1
Multiple Buffer Descriptor Table Entries for a Single Endpoint
Every endpoint direction requires at least one three-byte Buffer Descriptor entry. Thus, endpoint 0, a
bidirectional control endpoint, requires one BDT entry for the IN direction, and one for the OUT direction.
Using two BD entries also allows for double-buffering. Double-buffering BDs allows the USB module to
easily transfer data at the maximum throughput provided by the USB module. Double buffering allows the
MCU to process one BD while the USB module is processing the other BD.
To facilitate double-buffering, two buffer descriptor (BD) entries are needed for each endpoint direction.
One BD entry is the EVEN BD and the other is the ODD BD.
17.4.2.2
Addressing Buffer Descriptor Table Entries
The BDT addressing is hardwired into the module. The BDT occupies the first portion of the USB RAM.
To access endpoint data via the USB or MCU, the addressing mechanism of the buffer descriptor table
must be understood.
All enabled IN and OUT endpoint BD entries are indexed into the BDT to allow easy access via the USB
module or the MCU. The figure below shows the USB RAM organization. The figure shows that the first
entries in the USB RAM are dedicated to storage of the BDT entries - i.e. the first 30 bytes of the USB
RAM (0x00 to 0x1D) are used to implement the BDT.
MC9S08JM16 Series Data Sheet, Rev. 2
316
Freescale Semiconductor
Universal Serial Bus Device Controller (S08USBV1)
Table 17-21. USB RAM Organization
USB RAM
Offset
USB RAM Description of Contents
0x00
Endpoint 0 IN
Endpoint 0, OUT
Endpoint 1
Endpoint 2
BDT
Endpoint 3
Endpoint 4
Endpoint 5, Buffer EVEN
Endpoint 5, Buffer ODD
Endpoint 6, Buffer EVEN
0x1D
Endpoint 6, Buffer ODD
0x1E
RESERVED
0x1F
RESERVED
0x20
USB RAM available for endpoint buffers
0xFF
When the USB module receives a USB token on an enabled endpoint, it interrogates the BDT. The USB
module reads the corresponding endpoint BD entry and determines if it owns the BD and corresponding
data buffer.
17.4.2.3
Buffer Descriptor Formats
The buffer descriptors (BDs) are groups of registers that provide endpoint buffer control information for
the USB module and the MCU. The BDs have different meanings based on who is reading the BD in
memory.
The USB module uses the data stored in the BDs to determine:
• Who owns the buffer in system memory
• Data0 or Data1 PID
• Release Own upon packet completion
• Data toggle synchronization enable
• How much data to be transmitted or received
• Where the buffer resides in the buffer RAM.
The microcontroller uses the data stored in the BDs to determine:
•
•
•
Who owns the buffer in system memory
Data0 or Data1 PID
The received TOKEN PID
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
317
Universal Serial Bus Device Controller (S08USBV1)
•
•
How much data was transmitted or received.
Where the buffer resides in buffer memory
The BDT is composed of buffer descriptors (BD) which are used to define and control the actual buffers
in the USB RAM space. BDs always occur as a 3-bytes block. See Figure 17-19 for the BD example of
Endpoint 0 IN start from USB RAM offset 0x00.
The format for the buffer descriptor is shown in Table 17-22.
Offset
7
6
5
OWN
DATA0/1
R
0x00
W
4
3
2
1
0
0
0
BDTKPID[3] BDTKPID[3] BDTKPID[1] BDTKPID[0]
0
0
DTS
BDTSTALL
R
0x01
BC[7:0]
W
R
0x02
EPADR[9:4]
W
Figure 17-19. Buffer Descriptor Example
Table 17-22. Buffer Descriptor Table Fields
Field
OWN
DATA0/1
Description
OWN — This OWN bit determines who currently owns the buffer. The USB SIE generally writes a 0 to this bit
when it has completed a token. The USB module ignores all other fields in the BD when OWN=0. Once the BD
has been assigned to the USB module (OWN=1), the MCU must not change it in any way. This byte of the BD
must always be the last byte the MCU (firmware) updates when it initializes a BD. Although the hardware will
not block the MCU from accessing the BD while owned by the USB SIE, doing so may cause undefined
behavior and is generally not recommended.
0 The MCU has exclusive access to the entire BD
1 The USB module has exclusive access to the BD
Data Toggle — This bit defines if a DATA0 field (DATA0/1=0) or a DATA1 (DATA0/1=1) field was transmitted or
received. It is unchanged by the USB module.
0 Data 0 packet
1 Data 1 packet
The current token PID is written back to the BD by the USB module when a transfer completes. The values
BDTKPID[3:0] written back are the token PID values from the USB specification: 0x1 for an OUT token, 0x9 for and IN token
or 0xd for a SETUP token.
DTS
BDTSTALL
Data Toggle Synchronization— This bit enables data toggle synchronization.
0 No data toggle synchronization is performed.
1 Data toggle synchronization is performed.
BDT Stall — Setting this bit will cause the USB module to issue a STALL handshake if a token is received by
the SIE that would use the BDT in this location. The BDT is not consumed by the SIE (the OWN bit remains
and the rest of the BD is unchanged) when the BDTSTALL bit is set.
0 BDT stall is disabled
1 USB will issue a STALL handshake if a token is received by the SIE that would use the BDT in this location
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Table 17-22. Buffer Descriptor Table Fields (continued)
Field
BC[7:0]
EPADR[9:4]
17.4.3
Description
Byte Count — The Byte Count bits represent the 8-bit byte count. The USB module serial interface engine
(SIE) will change this field upon the completion of a RX transfer with the byte count of the data received. Note
that while USB supports packets as large as 1023 bytes for isochronous endpoints, this module limits packet
size to 64 bytes.
Endpoint Address— The endpoint address bits represent the upper 6 bits of the 10-bit buffer address within
the module’s local USB RAM. Bits [3:0] of EPADR are always zero, therefore the address of the buffer must
always start on a 16-byte aligned address within the local RAM. These bits are unchanged by the USB module.
This is NOT the address of the memory on the system bus. EPADR is relative to the start of the local USB RAM.
USB Transactions
When the USB module transmits or receives data, it will first compute the BDT address based on the
endpoint number, data direction, and which buffer is being used (even or odd), then it will read the BD.
Once the BD has been read, and if the OWN bit equals 1, the serial interface engine (SIE) will transfer the
packet data to or receive the packet data from the buffer pointed to by the EPADR field of the BD. When
the USB TOKEN is complete, the USB module will update the BDT and change the OWN bit to 0.
The STAT register is updated and the TOKDNE interrupt is set. When the microcontroller processes the
TOKDNE interrupt, it reads the status register. This gives the microcontroller all the information it needs
to process the endpoint. At this point the microcontroller can allocate a new BD, so additional USB data
can be transmitted or received for that endpoint, and it can process the previous BD. Figure 17-20 shows
a timeline for how a typical USB token would be processed.
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= USB Host
USB RST
= Function
SOF
USBRST
Interrupt Generated
SETUP TOKEN
SOF
Interrupt Generated
DATA
ACK
TOKDNE
Interrupt Generated
IN TOKEN
DATA
ACK
TOKDNE
Interrupt Generated
OUT TOKEN
DATA
ACK
TOKDNE
Interrupt Generated
Figure 17-20. USB Packet Flow
The USB has two sources of data overrun error:
• The memory latency to the local USB RAM interface may be too high and cause the receive buffer
to overflow. This is predominantly a hardware performance issue, usually caused by transient
memory access issues.
• The packet received may be larger than the negotiated MAXPACKET size. This is caused by a
software bug.
In the first case, the USB will respond with a NAK or bus timeout (BTO) as appropriate for the class of
transaction. The BTOERR bit will be set in the ERRSTAT register. Depending on the values of the
INTENB and ERRENB register, USB module may assert an interrupt to notify the CPU of the error. In
device mode the BDT is not written back nor is the TOKDNE interrupt triggered because it is assumed
that a second attempt will be queued at future time and will succeed.
In the second case of oversized data packets, the USB specification assumes correct software drivers on
both sides. The overrun is not due to memory latency but to a lack of space to put the excess data. NAK'ing
the packet will likely cause another retransmission of the already oversized packet data. In response to
oversized packets, the USB module will still ACK the packet for non-isochronous transfers. The data
written to memory is clipped to the MAXPACKET size so as not to corrupt the buffer space. The USB
module will assert the BUFERRF bit of the ERRSTAT register (which could trigger an interrupt, as above)
and a TOKDNE interrupt fails. The BDTKPID field of the BDT will not be “1111” because the BUFERRF
is not due to latency. The packet length field written back to the BDT will be the MAXPACKET value to
represent the length of the clipped data actually written to memory. From here the software can decide an
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appropriate course of action for future transactions — stalling the endpoint, canceling the transfer,
disabling the endpoint, etc.
17.4.4
USB Packet Processing
Packet processing for a USB device consists of managing buffers for IN (to the USB Host) and OUT (to
the USB device) transactions. Packet processing is further divided into request processing on Endpoint 0,
and data packet processing on the data endpoints.
17.4.4.1
USB Data Pipe Processing
Data pipe processing is essentially a buffer management task. The firmware is responsible for managing
the shared buffer RAM to ensure that a BD is always ready for the hardware to process (OWN bit = 1).
The device allocates buffers within the shared RAM, sets up the buffer descriptors, and waits for interrupts.
On receipt of a TOKDNE interrupt, the firmware reads the STAT register to determine which endpoint is
affected, then reads the corresponding BDT entry to determine what to do next.
When processing data packets, firmware is responsible for managing the size of the packet buffers to be
in compliance with the USB specification, and the physical limitations of this module. Packet sizes up to
64 bytes are supported on all endpoints. Isochronous endpoints also can only specify packet sizes up to 64
bytes.
Firmware is also responsible for setting the appropriate bits in the BDT. For most applications using bulk
packets (control, bulk, and interrupt-type transfers), the firmware will set the DTS, BC and EPADR fields
for each BD. For isochronous packets, firmware will set BC and EPADR fields. In all cases, firmware will
set the OWN bit to enable the endpoint for data transfers.
17.4.4.2
Request Processing on Endpoint 0
In most cases, commands to the USB device are directed to Endpoint 0. The host uses the “Standard
Requests” described in Chapter 9 of the USB specification to enumerate and configure the device. Class
drivers or product specific drivers running on the host send class (HID, Mass Storage, Imaging) and vendor
specific commands to the device on endpoint 0.
USB requests always follow a specific format:
• Host sends a SETUP token, followed by an 8-byte setup packet, and the device hardware can send
a handshake packet.
• If the setup packet specifies a data phase, the host and device may transfer up to 64 Kbytes of data
(either IN or OUT, not both).
• The request is terminated by a status phase.
Device firmware monitors the INTSTAT and STAT registers, the endpoint 0 buffer descriptors (BD’s), and
the contents of the setup packet to correctly execute the host’s request.
The flow for processing endpoint 0 requests is as follows:
1. Allocate 8-byte buffers for endpoint 0 OUT.
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2. Create BDT entries for Endpoint 0 OUT, and set the DTS and OWN bits to 1.
3. Wait for interrupt TOKDNE.
4. Read STAT register.
— The status register must show Endpoint 0, RX. If it does not, then assert the EPSTALL bit in
the endpoint control register.
5. Read Endpoint 0 OUT BD.
— Verify that the token type is a SETUP token. If it is not, then assert the EPSTALL bit in the
endpoint control register.
6. Decode and process the setup packet.
— If the direction field in the setup packet indicates an OUT transfer, then process the out data
phase to receive exactly the number of bytes specified in the wLength field of the setup packet.
— If the direction field in the setup packet indicates an IN transfer, then process the in data phase
to deliver no more than the number of bytes specified in the wLength field. Note that it is
common for the host to request more bytes than it needs, expecting the device to only send as
much as it needs to.
7. After processing the data phase (if there was one), create a zero-byte status phase transaction.
— This is accomplished for an OUT data phase (IN status phase) by setting the BC to 0 in the next
BD, while also setting OWN=1. For an IN data phase (OUT status phase), the host will send a
zero-byte packet to the device.
— Firmware can verify completion of the data phase by verifying the received token in the BD on
receipt of the TOKDNE interrupt. If the data phase was of type IN, then the status phase token
will be OUT. If the data phase was of type OUT, then the status phase token will be IN.
17.4.4.3
Endpoint 0 Exception Conditions
The USB includes a number of error checking and recovery mechanisms to ensure reliable data transfer.
One such exception occurs when the host sends a SETUP packet to a device, and the host never receives
the acknowledge handshake from the device. In this case, the host will retry the SETUP packet.
Endpoint 0 request handlers on the device must be aware of the possibility that after receiving a correct
SETUP packet, they could receive another SETUP packet before the data phase actually begins.
17.4.5
Start of Frame Processing
The USB host allocates time in 1.0 ms chunks called “Frames” for the purposes of packet scheduling. The
USB host starts each frame with a broadcast token called SOF (start of frame) that includes an 11-bit
sequence number. The TOKSOF interrupt is used to notify firmware when an SOF token was received.
Firmware can read the current frame number from the FRMNUML/FRMNUMH registers.
In general, the SOF interrupt is only monitored by devices using isochronous endpoints to help ensure that
the device and host remain synchronized.
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17.4.6
Suspend/Resume
The USB supports a single low-power mode called suspend. Getting into and out of the suspend state is
described in the following sections.
17.4.6.1
Suspend
The USB host can put a single device or the entire bus into the suspend state at any time. The MCU
supports suspend mode for low power. Suspend mode will be entered when the USB data lines are in the
idle state for more than 3 ms. Entry into suspend mode is announced by the SLEEPF bit in the INTSTAT
register.
Per the USB specification, a low-power bus-powered USB device is required to draw less than 500 µA in
suspend state. A high-power device that supports remote wakeup and has its remote wake-up feature
enabled by the host can draw up to 2.5 mA of current. After the initial 3 ms idle, the USB device will reach
this state within 7 ms. This low-current requirement means that firmware is responsible for entering stop3
mode once the SLEEPF flag has been set and before the USB module has been placed in the suspend state.
On receipt of resume signaling from the USB, the module can generate an asynchronous interrupt to the
MCU which brings the device out of stop mode and wakes up the clocks. Setting the USBRESMEN bit in
the USBCTL0 register immediately after the SLEEPF bit is set enables this asynchronous notification
feature. The USB resume signaling will then cause the LPRESF bit to be set, indicating a low-power
SUSPEND resume, which will wake the CPU from stop3 mode.
During normal operation, while the host is sending SOF packets, the USB module will not enter suspend
mode.
17.4.6.2
Resume
There are three ways to get out of the suspend state. When the USB module is in suspend state, the resume
detection is active even if all the clocks are disabled and the MCU is in stop3 mode. The MCU can be
activated from the suspend state by normal bus activity, a USB reset signal, or upstream resume (remote
wakeup).
17.4.6.2.1
Host Initiated Resume
The host signals a resume from suspend by initiating resume signaling (K state) for at least 20 ms followed
by a standard low-speed EOP signal. This 20 ms ensures that all devices in the USB network are awakened.
After resuming the bus, the host must begin sending bus traffic within 3 ms to prevent the device from
re-entering suspend mode.
Depending on the power mode the device is in while suspended, the notification for a host initiated resume
will be different:
• Run mode — RESUME must be set after SLEEPF becomes set to enable the RESUMEF interrupt.
Then, upon resume signaling, the RESUMEF interrupt will trigger after a K-state has been
observed on the USBDP/USBDN lines for 2.5 µs.
• Stop3 mode — USBRESMEN must be set after SLEEPF becomes set to arm the LPRESF bit.
Then, upon a K-state on the bus while the device is in stop3 mode, the LPRESF bit will be set,
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indicating a resume from low-power suspend. This will trigger an asynchronous interrupt to wake
the CPU from stop3 mode and resume clocks to the USB module.
NOTE
As a precaution, after LPRESF is set, firmware must check the state of the
USB bus to see if the K-state was a result of a transient event and not a true
host-initiated resume. If this is the case, then the device can drop back into
stop3 if necessary. To do this, the RESUME interrupt can be enabled in
conjunction with the USBRESMEN feature. Then, after LPRESF is set, and
a K-state is still detected approximately 2.5 µs after clocks have restarted,
firmware can check that the RESUMEF interrupt has triggered, indicating
resume signaling from the host.
17.4.6.2.2
USB Reset Signaling
Reset can wake a device from the suspend state.
17.4.6.2.3
Remote Wakeup
The USB device can send a resume event to the host by writing to the CRESUME bit. Firmware must first
set the bit for the time period required by the USB Specification Rev. 2.0 (Section 7.1.7.7) and then clear
it to 0.
17.4.7
Resets
The module supports multiple types of resets. The first is a bus reset generated by the USB Host, the
second is a module reset generated by the MCU.
17.4.7.1
USB Bus Reset
At any time, the USB host may issue a reset to one or all of the devices attached to the bus. A USB reset
is defined as a period of single ended zero (SE0) on the cable for greater than 2.5 μs. When the device
detects reset signaling, it resets itself to the unconfigured state, and sets its USB address zero. The USB
host uses reset signaling to force one or all connected devices into a known state prior to commencing
enumeration.
The USB module responds to reset signaling by asserting the USBRST interrupt in the INTSTAT register.
Software is required to service this interrupt to ensure correct operation of the USB.
17.4.7.2
USB Module Reset
USB module resets are initiated on-chip. During a module reset, the USB module is configured in the
default mode. The USB module can also be forced into its reset state by setting the USBRESET bit in the
USBCTL0 register. The default mode includes the following settings:
• Interrupts masked.
• USB clock enabled
• USB voltage regulator disabled
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•
•
•
•
USB transceiver disabled
USBDP pullup disabled
Endpoints disabled
USB address register set to zero
17.4.8
Interrupts
Interrupts from the INTSTAT register signify events which occur during normal operation — USB start of
frame tokens (TOKSOF), packet completion (TOKDNE), USB bus reset (USBRST), endpoint errors
(ERROR), suspend and resume (SLEEP and RESUME), and endpoint stalled (STALL).
The ERRSTAT interrupts carry information about specific types of errors, which is needed on an
application specific basis. Using ERRSTAT, an application can determine exactly why a packet transfer
failed — due to CRC error, PID check error and so on.
Both registers are maskable via the INTENB and ERRENB registers. The INTSTAT and ERRSTAT are
used to signal interrupts in a two-level structure. Unmasked interrupts from the ERRSTAT register are
reported in the INTSTAT register.
Note that the interrupt registers work in concert with the STAT register. On receipt of an INTSTAT
interrupt, software can check the STAT register and determine which BDT entry was affected by the
transaction.
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Chapter 18
Development Support
18.1
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.
18.1.1
Forcing Active Background
The method for forcing active background mode depends on the specific HCS08 derivative. For the
MC9S08JM16 Series, you can force active background mode by holding the BKGD pin low as the MCU
exits the reset condition independent of what caused the reset. If no debug pod is connected to the BKGD
pin, the MCU will always reset into normal operating mode.
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18.1.2
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)
18.2
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.
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•
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 18-1. BDM Tool Connector
18.2.1
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 first (MSB first). For a detailed description of the communications protocol, refer to Section 18.2.2,
“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 18.2.2, “Communication Details,” for more detail.
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When no debugger pod is connected to the 6-pin BDM interface connector, the internal pullup on BKGD
chooses normal operating mode. When a debug pod is connected to BKGD it is possible to force the MCU
into active background mode after reset. The specific conditions for forcing active background depend
upon the HCS08 derivative (refer to the introduction to this Development Support section). It is not
necessary to reset the target MCU to communicate with it through the background debug interface.
18.2.2
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.
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Figure 18-2 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 18-2. BDC Host-to-Target Serial Bit Timing
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Figure 18-3 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 must sample the bit level about 10 cycles after it started the bit time.
BDC CLOCK
(TARGET MCU)
HOST DRIVE
TO BKGD PIN
TARGET MCU
SPEEDUP PULSE
HIGH-IMPEDANCE
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 18-3. BDC Target-to-Host Serial Bit Timing (Logic 1)
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Figure 18-4 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 18-4. BDM Target-to-Host Serial Bit Timing (Logic 0)
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18.2.3
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 18-1 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 18-1 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)
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Table 18-1. 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.
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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.
18.2.4
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.
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18.3
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 18.3.6, “Hardware Breakpoints.”
18.3.1
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)
18.3.2
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
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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 18.3.5, “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.
18.3.3
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.
18.3.4
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.
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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.
18.3.5
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.
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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.
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18.3.6
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 18.3.5, “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.
18.4
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.
18.4.1
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.
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18.4.1.1
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
R
6
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 18-5. BDC Status and Control Register (BDCSCR)
Table 18-2. 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
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)
3
CLKSW
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
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Table 18-2. 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 must 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 MC9S08JM16 Series 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
18.4.1.2
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 18.2.4, “BDC Hardware Breakpoint.”
18.4.2
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.
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 18-6. System Background Debug Force Reset Register (SBDFR)
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Table 18-3. 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.
18.4.3
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.
18.4.3.1
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.
18.4.3.2
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.
18.4.3.3
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.
18.4.3.4
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.
18.4.3.5
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.
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18.4.3.6
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.
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18.4.3.7
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 18-7. Debug Control Register (DBGC)
Table 18-4. 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
MC9S08JM16 Series Data Sheet, Rev. 2
346
Freescale Semiconductor
Development Support
18.4.3.8
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 18-8. Debug Trigger Register (DBGT)
Table 18-5. 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)
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
347
Development Support
18.4.3.9
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 18-9. Debug Status Register (DBGS)
Table 18-6. 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
MC9S08JM16 Series Data Sheet, Rev. 2
348
Freescale Semiconductor
Appendix A
Electrical Characteristics
A.1
Introduction
This appendix contains electrical and timing specifications for the MC9S08JM16 series of
microcontrollers available at the time of publication.
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).
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
349
Appendix A Electrical Characteristics
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
IDD
120
mA
Tstg
–55 to 150
°C
Maximum current into VDD
Storage 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 VDD 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.
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
Num
C
Rating
Symbol
Value
Unit
Temp.
Code
C
1
T Operating temperature range (packaged)
TA
–40 to 85
°C
2
D Maximum junction temperature
TJ
135
°C
θJA
81
83
70
°C/W
Thermal resistance
Single layer board —
3
32-pin LQFP
48-pin QFN
44-pin LQFP
T
—
Four layer board (2s2p) —
32-pin LQFP
48-pin QFN
44-pin LQFP
53
29
48
MC9S08JM16 Series Data Sheet, Rev. 2
350
Freescale Semiconductor
Appendix A Electrical Characteristics
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
Solving Equation A-1 and Equation A-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 A-3 by
measuring PD (at equilibrium) for a known TA. Using this value of K, the values of TJ and PD can be
obtained by solving Equation A-1 and Equation A-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 must 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) 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
Description
Symbol
Value
Unit
Series resistance
R1
1500
Ω
Storage capacitance
C
100
pF
Number of pulse per pin
—
3
Minimum input voltage limit
—
–2.5
V
Maximum input voltage limit
—
7.5
V
Latch-up
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
351
Appendix A Electrical Characteristics
Table A-5. ESD and Latch-up Protection Characteristics
Num
A.6
Rating
Symbol
Min
Max
Unit
1
Human body model (HBM)
VHBM
±2000
—
V
2
Charge device model (CDM)
VCDM
±500
—
V
3
Latch-up current at TA = 85°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 7. DC Characteristics
Num C
1
Parameter
Operating voltage
Symbol
2
Output high voltage — Low drive (PTxDSn = 0)
5 V, ILoad = –4 mA
3 V, ILoad = –2 mA
5 V, ILoad = –2 mA
3 V, ILoad = –1 mA
2
P Output high voltage — High drive (PTxDSn = 1)
5 V, ILoad = –15 mA
3 V, ILoad = –8 mA
5 V, ILoad = –8 mA
3 V, ILoad = –4 mA
Min
Typical1
Max.
Unit
2.7
—
5.5
V
VDD – 1.5
VDD – 1.5
VDD – 0.8
VDD – 0.8
—
—
—
—
—
—
—
—
VOH
V
VDD – 1.5
VDD – 1.5
VDD – 0.8
VDD – 0.8
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
1.5
1.5
0.8
0.8
Output low voltage — Low drive (PTxDSn = 0)
5 V, ILoad = 4 mA
3 V, ILoad = 2 mA
5 V, ILoad = 2 mA
3 V, ILoad = 1 mA
3
4
5
6
P Output low voltage — High drive (PTxDSn = 1)
5 V, ILoad = 15 mA
3 V, ILoad = 8 mA
5 V, ILoad = 8 mA
3 V, ILoad = 4 mA
VOL
V
—
—
—
—
—
—
—
—
1.5
1.5
0.8
0.8
P Output high current — Max. total IOH for all ports
5V
3V
IOHT
—
—
—
—
100
60
mA
5V
3V
IOLT
—
—
—
—
100
60
mA
0.65 × VDD
0.70 × VDD
—
—
V
—
0.35 × VDD
P Output low current — Max. total IOL for all ports
C Input high voltage; all digital inputs
VIH
5V
3V
7
C Input low voltage; all digital inputs
VIL
—
8
C Input hysteresis; all digital inputs
Vhys
0.06 × VDD
9
C Input leakage current (per pin); input only pins
|IIn|
—
0.1
1
μA
10
P Hi-Z (off-state) leakage current (per pin)
|IOZ|
—
0.1
1
μA
mV
MC9S08JM16 Series Data Sheet, Rev. 2
352
Freescale Semiconductor
Appendix A Electrical Characteristics
Table 7. DC Characteristics (continued)
Num C
11
Parameter
P Internal pullup
resistors3
4
12
P Internal pulldown resistors
13
T Internal pullup resistor to USBDP (to VUSB33)
Symbol
Min
Typical1
Max.
Unit
RPU
20
45
65
kΩ
RPD
20
45
65
kΩ
900
1425
1300
2400
1575
3090
kΩ
0
0
—
—
2
–0.2
mA
0
0
—
—
25
–5
CIn
—
—
8
pF
V
Idle RPUPD
Transmit
14
D DC injection current5 6 7 8
Single pin limit
VIN > VDD
VIN < VSS
Total MCU limit, includes sum of all stressed pins
VIN > VDD
VIN < VSS
IIC
mA
15
D Input capacitance; all non-supply pins
16
D RAM retention voltage
VRAM
—
0.6
1.0
17
D POR re-arm voltage
VPOR
0.9
1.4
2.0
V
18
D POR re-arm time
tPOR
10
—
—
μs
3.9
4.0
4.0
4.1
4.1
4.2
2.48
2.54
2.56
2.62
2.64
2.70
4.5
4.6
4.6
4.7
4.7
4.8
4.2
4.3
4.3
4.4
4.4
4.5
2.84
2.90
2.92
2.98
3.00
3.06
2.66
2.72
2.74
2.80
2.82
2.88
Vhys
—
—
100
60
—
—
mV
mV
VBG
1.19
1.20
1.21
V
19
20
21
22
23
P
P
P
C
P
24
C
25
T
26
C
Low-voltage detection threshold —
High range
VDD falling
VDD rising
Low-voltage detection threshold —
Low range
VDD falling
VDD rising
Low-voltage warning threshold —
High range 1
VDD falling
VDD rising
Low-voltage warning threshold —
High range 0
VDD falling
VDD rising
Low-voltage warning threshold
Low range 1
VDD falling
VDD rising
Low-voltage warning threshold —
Low range 0
VDD falling
VDD rising
VLVD1
VLVD0
VLVW3
VLVW2
VLVW1
VLVW0
V
V
V
V
V
V
Low-voltage inhibit reset/recover hysteresis
1
2
+5 V
+3 V
Bandgap voltage reference
factory trimmed at VDD = 5.0 V, Temp = 25°C
Typical values are based on characterization data at 25°C unless otherwise stated.
Maximum is highest voltage that POR is guaranteed.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
353
Appendix A Electrical Characteristics
3
4
5
6
7
8
Measured with VIn = VSS.
Measured with VIn = VDD.
Power supply must maintain regulation within operating VDD 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 clock rate is very low (which would reduce overall power
consumption).
All functional non-supply pins are internally clamped to VSS and VDD.
Input must be current limited to the value specified. To determine the value of the required current-limiting resistor,
calculate resistance values for positive and negative clamp voltages, then use the larger of the two values.
The RESET pin does not have a clamp diode to VDD. Do not drive this pin above VDD.
Typical VOL vs. IOL AT VDD = 5V
Hot (85°C)
1.400
0.6
Room (25°C)
1.200
Room (25°C)
0.5
Cold (-40°C)
1.000
Cold (-40°C)
0.4
VOL (v)
VOL (v)
0.7
Typical VOL vs. I OL AT VDD = 3V
0.3
Hot (85°C)
0.800
0.600
0.2
0.400
0.1
0.200
0.0
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
0.000
15
0.0
I OL (mA)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
I OL (mA)
Figure A-1. Typical Low-Side Drive (Sink) Characteristics – High Drive (PTxDSn = 1)
T y p ic a l V O L v s . IO L A T V DD = 3 V
T ypical V O L v s. I O L AT V D D = 5V
0.5
0 .8
Hot (85°C)
0.4
Room (25°C )
0.4
Cold (-40°C)
VOL (v)
VOL (v)
0.3
0.3
0.2
H o t (8 5 ° C )
0 .7
R o o m (2 5 ° C )
0 .6
C o ld (-4 0 ° C )
0 .5
0 .4
0 .3
0.2
0 .2
0.1
0 .1
0.1
0 .0
0.0
0
1
2
3
0
1
2
3
I O L (m A )
IOL (m A)
Figure A-2. Typical Low-Side Drive (Sink) Characteristics – Low Drive (PTxDSn = 0)
MC9S08JM16 Series Data Sheet, Rev. 2
354
Freescale Semiconductor
Appendix A Electrical Characteristics
Typical VDD - VOH vs. IOH AT VDD=3V
Typical VDD - VOH vs. IOH AT VDD = 5V
0.6
0.4
1.2
Hot (85°C)
Room (25°C)
VDD - VOH (v)
VDD - VOH (v)
0.8
Cold (-40°C)
0.2
Hot (85°C)
1.0
Room (25°C)
0.8
Cold (-40°C)
0.6
0.4
0.2
0.0
0 -1 -2 -3 -4 -5 -6 -7 -8 -9 -10 -11 -12 -13 -14 -15
0.0
0
IOH (mA)
-1 -2 -3 -4 -5 -6 -7 -8 -9 -10 -11 -12 -13 -14 -15
IOH (mA)
Figure A-3. Typical High-Side Drive (Source) Characteristics – High Drive (PTxDSn = 1)
Typical VDD - VOH vs. IOH AT VDD=3V
Typical VDD - VOH vs. IOH AT VDD = 5V
1.2
Hot (85°C)
Room (25°C)
0.6
VDD - VOH (v)
VDD - VOH (v)
0.8
Cold (-40°C)
0.4
0.2
Hot (85°C)
1.0
Room (25°C)
0.8
Cold (-40°C)
0.6
0.4
0.2
0.0
0.0
0
-1
-2
-3
0
IOH (mA)
-1
IOH (mA)
-2
-3
Figure A-4. Typical High-Side Drive (Source) Characteristics – Low Drive (PTxDSn = 0)
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
355
Appendix A Electrical Characteristics
A.7
Supply Current Characteristics
Table A-6. Supply Current Characteristics
VDD (V)
Typical1
Max2
5
1.1
1.6
3
0.8
1.6
5
4.0
7
3
3.8
7
5
22
30
3
21
30
5
0.80
–40 °C
25 °C
85 °C
3
0.80
–40 °C
25 °C
85 °C
5
0.90
3
0.90
5
300
nA
3
300
nA
5
110
μA
3
90
μA
5
5
μA
3
5
μA
mA
Num
C
Parameter
1
C
Run supply current3 measured at
(Core clock = 2 MHz, fBus = 1 MHz, BLPE mode)
2
3
P
C
Symbol
Run supply current3 measured at
(Core clock = 8 MHz, fBus = 4 MHz, FBE mode)
Unit
mA
RIDD
Run supply current3 measured at
(Core clock = 48 MHz, fBus = 24 MHz, PEE mode)
mA
mA
Stop2 mode supply current
4
–40 °C
25 °C
85 °C
P
S2IDD
3
3
20
3
3
20
μA
μA
Stop3 mode supply current
5
P
S3IDD
–40 °C
25 °C
85 °C
6
7
8
P
P
P
Adder to stop2 or stop3 for RTC enabled4, 25°C
ΔISRTC
Adder to stop3 for LVD enabled
(LVDE = LVDSE = 1)
ΔISLVD
Adder to stop3 for oscillator enabled5
(ERCLKEN = 1 and EREFSTEN = 1)
ΔISOSC
ΔIUSBE
5
1.5
ISUSP
5
270
9
T
USB module enable current6
10
T
USB suspend current7
3
3
20
3
3
20
500
μA
μA
μA
1
Typicals are measured at 25°C.
Values given here are preliminary estimates prior to completing characterization.
3
All modules except USB and ADC active, Oscillator disabled (ERCLKEN = 0), using external clock resource for input, and does
not include any DC loads on port pins.
4
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 560 μA at 5 V and 422 μA at 3 V with fBus = 1 MHz.
5 Values given under the following conditions: low range operation (RANGE = 0), low power mode (HGO = 0).
2
MC9S08JM16 Series Data Sheet, Rev. 2
356
Freescale Semiconductor
Appendix A Electrical Characteristics
6
Here USB module is enabled and clocked at 48 MHz (USBEN = 1, USBVREN =1, USBPHYEN = 1 and USBPU = 1), and D+
and D– pull down by two 15.1 kΩ resisters independently. The current consumption may be much higher when the packets are
being transmitted through the attached cable.
7
MCU enters stop3 mode, USB bus in idle state. The USB suspend current will be dominated by the D+ pullup resister.
A.8
Analog Comparator (ACMP) Electricals
Table A-7. Analog Comparator Electrical Specifications
Num
C
Symbol
Min.
Typical
Max.
Unit
1
—
Supply voltage
VDD
2.7
—
5.5
V
2
D
Supply current (active)
IDDAC
—
20
35
μA
3
D
Analog input voltage
VAIN
VSS – 0.3
—
VDD
V
4
D
Analog input offset voltage
VAIO
—
20
40
mV
5
D
Analog comparator hysteresis
VH
3.0
6.0
20.0
mV
6
D
Analog input leakage current
IALKG
—
—
1.0
μA
7
D
Analog comparator initialization delay
tAINIT
—
—
1.0
μs
A.9
Rating
ADC Characteristics
Table A-8. 5 Volt 12-bit ADC Operating Conditions
Symbol
Min.
Typical1
Max.
Unit
Absolute
VDDAD
2.7
—
5.5
V
Delta to VDD (VDD–VDDAD)2
ΔVDDAD
–100
0
100
mV
Delta to VSS (VSS–VSSAD)2
ΔVSSAD
–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
—
—
—
—
2
5
—
—
—
—
5
10
—
—
10
Characteristic
Supply voltage
Ground voltage
Conditions
12 bit mode
fADCK > 4 MHz
fADCK < 4 MHz
Analog Source
Resistance
10 bit mode
fADCK > 4 MHz
fADCK < 4 MHz
kΩ
RAS
8 bit mode (all valid fADCK)
Comment
External to MCU
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
357
Appendix A Electrical Characteristics
Table A-8. 5 Volt 12-bit ADC Operating Conditions (continued)
Characteristic
Conditions
ADC
Conversion
Clock Freq.
Symbol
High Speed (ADLPC=0)
fADCK
Low Power (ADLPC=1)
Min.
Typical1
Max.
0.4
—
8.0
0.4
—
4.0
Unit
Comment
MHz
Typical values assume VDDAD = 5.0 V, Temp = 25 °C, fADCK= 1.0 MHz unless otherwise stated. Typical values are for reference
only and are not tested in production.
2
DC potential difference.
1
SIMPLIFIED
INPUT PIN EQUIVALENT
CIRCUIT
ZADIN
Pad
leakage
due to
input
protection
ZAS
RAS
SIMPLIFIED
CHANNEL SELECT
CIRCUIT
RADIN
ADC SAR
ENGINE
+
VADIN
VAS
+
–
CAS
–
RADIN
INPUT PIN
INPUT PIN
RADIN
RADIN
INPUT PIN
CADIN
Figure A-5. ADC Input Impedance Equivalency Diagram
MC9S08JM16 Series Data Sheet, Rev. 2
358
Freescale Semiconductor
Appendix A Electrical Characteristics
Table A-9. 5 Volt 12-bit ADC Characteristics (VREFH = VDDAD, VREFL = VSSAD)
C
Symbol
Min.
Typical1
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
Supply Current
ADLPC=0
ADLSMP=0
ADCO=1
T
IDDAD
—
0.582
1
mA
IDDAD
—
0.011
1
μA
2
3.3
5
1.25
2
3.3
—
20
—
—
40
—
—
3.5
—
—
23.5
—
—
±3.0
±10.0
—
±1
±2.5
Characteristic
Conditions
Supply Current
Stop, Reset, Module Off
ADC
Asynchronous
Clock Source
High Speed (ADLPC=0)
Conversion
Time (Including
sample time)
Short Sample
(ADLSMP=0)
Sample Time
T
Low Power (ADLPC=1)
T
fADACK
tADC
Long Sample (ADLSMP=1)
Short Sample
(ADLSMP=0)
T
tADS
Long Sample (ADLSMP=1)
Total
Unadjusted
Error
Differential
Non-Linearity
Integral
Non-Linearity
Zero-Scale
Error
MHz
12 bit mode
T
10 bit mode
P
8 bit mode
T
—
±0.5
±1.0
12 bit mode
T
—
±1.75
±4.0
10 bit mode3
P
—
±0.5
±1.0
8 bit mode2
T
—
±0.3
±0.5
12 bit mode
T
—
±1.5
±4.0
10 bit mode
T
—
±0.5
±1.0
8 bit mode
T
—
±0.3
±0.5
12 bit mode
T
—
±1.5
±6.0
10 bit mode
P
—
±0.5
±1.5
8 bit mode
T
—
±0.5
±0.5
ETUE
DNL
INL
EZS
ADCK
cycles
ADCK
cycles
LSB2
Comment
tADACK =
1/fADACK
See Table
10.13 for
conversion
time
variances
Includes
quantization
LSB2
LSB2
LSB2
VADIN =
VSSAD
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
359
Appendix A Electrical Characteristics
Table A-9. 5 Volt 12-bit ADC Characteristics (VREFH = VDDAD, VREFL = VSSAD) (continued)
Min.
Typical1
Max.
—
±1
±4.0
—
±0.5
±1
—
±0.5
±0.5
—
–1 to 0
–1 to 0
—
—
±0.5
8 bit mode
—
—
±0.5
12 bit mode
—
±1
±10
—
±0.2
±2.5
—
±0.1
±1
—
1.396
—
—
3.266
—
—
3.638
—
Characteristic
Full-Scale
Error
Conditions
C
12 bit mode
T
10 bit mode
P
8 bit mode
T
Symbol
EFS
12 bit mode
Quantization
Error
Input Leakage
Error
10 bit mode
10 bit mode
D
D
EQ
EIL
8 bit mode
Temp Sensor
Voltage
25°C
Temp Sensor
–40 °C — 25 °C
Slope
25 °C — 125 °C
D
VTEMP25
D
m
Unit
Comment
LSB2
VADIN =
VDDAD
LSB2
LSB2
Pad
leakage4 *
RAS
V
mV/°C
1
Typical values assume VDDAD = 5.0 V, Temp = 25°C, 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
Monotonicity and no-missing-codes guaranteed in 10-bit and 8-bit modes
4 Based on input pad leakage current. Refer to pad electricals.
MC9S08JM16 Series Data Sheet, Rev. 2
360
Freescale Semiconductor
Appendix A Electrical Characteristics
A.10
External Oscillator (XOSC) Characteristics
Table A-10. Oscillator Electrical Specifications (Temperature Range = –40 to 85°C Ambient)
Num
C
Rating
Oscillator crystal or resonator (EREFS = 1, ERCLKEN = 1)
Low range (RANGE = 0)
High range (RANGE = 1) FEE or FBE mode 2
High range (RANGE = 1) PEE or PBE mode 3
High range (RANGE = 1, HGO = 1) BLPE mode
High range (RANGE = 1, HGO = 0) BLPE mode
1
C
2
— Load capacitors
3
—
4
Series resistor
Low range, low gain (RANGE = 0, HGO = 0)
Low range, high gain (RANGE = 0, HGO = 1)
High range, low gain (RANGE = 1, HGO = 0)
—
High range, high gain (RANGE = 1, HGO = 1)
≥ 8 MHz
4 MHz
1 MHz
5
6
T
T
Symbol
Min
Typ1
Max
Unit
flo
fhi-fll
fhi-pll
fhi-hgo
fhi-lp
32
1
1
1
1
—
—
—
—
—
38.4
5
16
16
8
kHz
MHz
MHz
MHz
MHz
C1, C2
Feedback resistor
Low range (32 kHz to 38.4 kHz)
High range (1 MHz to 16 MHz)
See crystal or resonator
manufacturer’s recommendation.
RF
RS
Crystal start-up time 4
Low range, low gain (RANGE = 0, HGO = 0)
Low range, high gain (RANGE = 0, HGO = 1)
High range, low gain (RANGE = 1, HGO = 0)5
High range, high gain (RANGE = 1, HGO = 1)5
t
t
CSTL-LP
CSTL-HGO
t
CSTH-LP
t
CSTH-HGO
Square wave input clock frequency (EREFS = 0, ERCLKEN = 1)
FEE or FBE mode 2
PEE or PBE mode 3
BLPE mode
fextal
10
1
MΩ
—
—
—
0
100
0
—
—
—
—
—
—
0
0
0
0
10
20
—
—
—
—
200
400
5
15
—
—
—
—
0.03125
1
0
—
—
—
5
16
40
kΩ
ms
MHz
1
Typical data was characterized at 3.0 V, 25°C or is recommended value.
When MCG is configured for FEE or FBE mode, input clock source must be divided using RDIV to within the range of 31.25 kHz
to 39.0625 kHz.
3 When MCG is configured for PEE or PBE mode, input clock source must be divided using RDIV to within the range of 1 MHz to
2 MHz.
4 This parameter is characterized and not tested on each device. Proper PC board layout procedures must be followed to achieve
specifications.
5
4 MHz crystal.
2
MCU
EXTAL
XTAL
RF
C1
Crystal or Resonator
RS
C2
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
361
Appendix A Electrical Characteristics
A.11
MCG Specifications
Table A-11. MCG Frequency Specifications (Temperature Range = –40 to 125°C Ambient)
Num C
Rating
Internal reference frequency — factory trimmed at VDD
= 5 V and temperature = 25 °C
Typical
Max.
Unit
fint_ft
—
31.25
—
kHz
P
2
P Average internal reference frequency — untrimmed1
fint_ut
25
32.7
41.66
kHz
3
P Average internal reference frequency — user trimmed
fint_t
31.25
—
39.0625
kHz
4
D Internal reference startup time
tirefst
—
60
100
μs
fdco_ut
25.6
33.48
42.66
MHz
fdco_t
32
—
40
MHz
DCO output frequency range — untrimmed
value provided for reference: fdco_ut = 1024 X fint_ut
5
—
6
P DCO output frequency range — trimmed
7
C
Resolution of trimmed DCO output frequency at fixed
voltage and temperature (using FTRIM)
Δfdco_res_t
—
±0.1
±0.2
%fdco
8
C
Resolution of trimmed DCO output frequency at fixed
voltage and temperature (not using FTRIM)
Δfdco_res_t
—
±0.2
±0.4
%fdco
9
P
Total deviation of trimmed DCO output frequency over
voltage and temperature
Δfdco_t
—
0.5
–1.0
±2
%fdco
10
C
Total deviation of trimmed DCO output frequency over
fixed voltage and temperature range of 0 – 70 °C
Δfdco_t
—
± 0.5
±1
%fdco
11
C FLL acquisition time2
tfll_acquire
—
—
1
ms
12
D PLL acquisition time3
tpll_acquire
—
—
1
ms
13
C
CJitter
—
0.02
0.2
%fdco
14
D VCO operating frequency
fvco
7.0
—
55.0
MHz
15
D PLL reference frequency range
fpll_ref
1.0
—
2.0
MHz
16
T
fpll_jitter_2ms
—
0.5905
—
%fpll
17
T Jitter of PLL output clock measured over 625 ns
fpll_jitter_625ns
—
0.5665
—
%fpll
18
D Lock entry frequency tolerance 6
Dlock
±1.49
—
±2.98
%
Dunl
±4.47
—
±5.97
%
s
19
2
Min.
1
1
1
Symbol
Long term Jitter of DCO output clock (averaged over
2ms interval)4
Long term accuracy of PLL output clock (averaged over
2 ms)
D Lock exit frequency tolerance
7
20
D Lock time — FLL
tfll_lock
—
—
tfll_acquire +
1075(1/fint_t)
21
D Lock time — PLL
tpll_lock
—
—
tpll_acquire +
1075(1/fpll_ref)
s
22
D
Loss of external clock minimum frequency —
RANGE = 0
floc_low
(3/5) × fint
—
—
kHz
23
D
Loss of external clock minimum frequency —
RANGE = 1
floc_high
(16/5) × fint
—
—
kHz
TRIM register at default value (0x80) and FTRIM control bit at default value (0x0).
This specification applies to any time the FLL reference source or reference divider is changed, trim value changed or changing
from FLL disabled (BLPE, BLPI) to FLL enabled (FEI, FEE, FBE, FBI). If a crystal/resonator is being used as the reference, this
specification assumes it is already running.
MC9S08JM16 Series Data Sheet, Rev. 2
362
Freescale Semiconductor
Appendix A Electrical Characteristics
3
This specification applies to any time the PLL VCO divider or reference divider is changed, or changing from PLL disabled (BLPE,
BLPI) to PLL enabled (PBE, PEE). If a crystal/resonator is being used as the reference, this specification assumes it is already
running.
4
Jitter is the average deviation from the programmed frequency measured over the specified interval at maximum fBus.
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 VDD and VSS and variation in crystal oscillator frequency increase the CJitter percentage for a given
interval.
5
Jitter measurements are based upon a 48 MHz MCGOUT clock frequency.
6
Below Dlock minimum, the MCG is guaranteed to enter lock. Above Dlock maximum, the MCG will not enter lock. But if the MCG
is already in lock, then the MCG may stay in lock.
7
Below Dunl minimum, the MCG will not exit lock if already in lock. Above Dunl maximum, the MCG is guaranteed to exit lock.
A.12
AC Characteristics
This section describes ac timing characteristics for each peripheral system.
A.12.1
Control Timing
Table A-12. Control Timing
Num
C
Parameter
Symbol
Min
Typical1
Max
Unit
—
24
MHz
1
Bus frequency (tcyc = 1/fBus)
fBus
DC
2
Internal low-power oscillator period
tLPO
700
1300
μs
3
External reset pulse width2
textrst
100
—
ns
4
Reset low drive
trstdrv
66 × tcyc
—
ns
5
Active background debug mode latch setup time
tMSSU
500
—
ns
6
Active background debug mode latch hold time
tMSH
100
—
ns
7
IRQ pulse width
Asynchronous path2
Synchronous path3
tILIH, tIHIL
100
1.5 × 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)4
Slew rate control disabled (PTxSE = 0)
Slew rate control enabled (PTxSE = 1)
high output drive (PTxDS = 1), (load = 50 pF)
Slew rate control disabled (PTxSE = 0)
Slew rate control enabled (PTxSE = 1)
—
tRise, tFall
40
75
8
9
—
ns
11
35
Typical values are based on characterization data at VDD = 5.0 V, 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 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.
4 Timing is shown with respect to 20% V
DD and 80% VDD levels. Temperature range –40 °C to 85 °C.
1
2
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
363
Appendix A Electrical Characteristics
textrst
RESET PIN
Figure A-6. Reset Timing
tIHIL
IRQ/KBIPx
IRQ/KBIPx
tILIH
Figure A-7. IRQ/KBIPx Timing
A.12.2
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-13. TPM Input Timing
NUM
C
1
—
2
Function
Symbol
Min
Max
Unit
External clock frequency
fTPMext
DC
fBus/4
MHz
—
External clock period
tTPMext
4
—
tcyc
3
D
External clock high time
tclkh
1.5
—
tcyc
4
D
External clock low time
tclkl
1.5
—
tcyc
5
D
Input capture pulse width
tICPW
1.5
—
tcyc
tTPMext
tclkh
TPMxCLK
tclkl
Figure A-8. Timer External Clock
MC9S08JM16 Series Data Sheet, Rev. 2
364
Freescale Semiconductor
Appendix A Electrical Characteristics
tICPW
TPMxCHn
TPMxCHn
tICPW
Figure A-9. Timer Input Capture Pulse
A.12.3
SPI Characteristics
Table A-14 and Figure A-10 through Figure A-13 describe the timing requirements for the SPI system.
Table A-14. SPI Electrical Characteristic
Num1
C
1
D
2
D
3
D
4
D
5
D
6
D
7
D
8
D
9
D
10
D
11
D
12
D
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
Access time, slave3
tA
0
40
ns
4
tdis
—
40
ns
Master
Slave
tSO
tSO
25
25
—
—
ns
ns
Master
Slave
tHO
tHO
–10
–10
—
—
ns
ns
Operating frequency
Cycle time
Enable lead time
Enable lag time
Data setup time (inputs)
Data hold time (inputs)
Disable time, slave
Data setup time (outputs)
Data hold time (outputs)
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
365
Appendix A Electrical Characteristics
1
Refer to Figure A-10 through Figure A-13.
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
Time to data active from high-impedance state.
4
Hold time to high-impedance state.
2
SS1
(OUTPUT)
5
4
SCK
(CPOL = 1)
(OUTPUT)
5
4
6
MISO
(INPUT)
7
MSB IN2
10
MOSI
(OUTPUT)
3
1
2
SCK
(CPOL = 0)
(OUTPUT)
BIT 6 . . . 1
LSB IN
11
10
MSB OUT2
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-10. SPI Master Timing (CPHA = 0)
MC9S08JM16 Series Data Sheet, Rev. 2
366
Freescale Semiconductor
Appendix A Electrical Characteristics
SS(1)
(OUTPUT)
1
3
2
SCK
(CPOL = 0)
(OUTPUT)
5
4
SCK
(CPOL = 1)
(OUTPUT)
5
4
6
MISO
(INPUT)
7
MSB IN(2)
BIT 6 . . . 1
LSB IN
11
10
MOSI
(OUTPUT)
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-11. SPI Master Timing (CPHA = 1)
SS
(INPUT)
3
1
SCK
(CPOL = 0)
(INPUT)
5
4
2
SCK
(CPOL = 1)
(INPUT)
5
4
8
MISO
(OUTPUT)
SLAVE
6
MOSI
(INPUT)
9
11
10
MSB OUT
BIT 6 . . . 1
SLAVE LSB OUT
SEE
NOTE
7
MSB IN
BIT 6 . . . 1
LSB IN
NOTE:
1. Not defined but normally MSB of character just received
Figure A-12. SPI Slave Timing (CPHA = 0)
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
367
Appendix A Electrical Characteristics
SS
(INPUT)
3
1
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-13. SPI Slave Timing (CPHA = 1)
MC9S08JM16 Series Data Sheet, Rev. 2
368
Freescale Semiconductor
Appendix A Electrical Characteristics
A.13
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.
Table A-15. Flash Characteristics
Num
C
Characteristic
Symbol
Min
Typical1
Max
Unit
1
Supply voltage for program/erase
Vprog/erase
2.7
5.5
V
2
Supply voltage for read operation
VRead
2.7
5.5
V
3
Internal FCLK frequency2
fFCLK
150
200
kHz
4
Internal FCLK period (1/FCLK)
tFcyc
5
6.67
μs
5
Byte program time (random location)(2)
tprog
9
tFcyc
6
Byte program time (burst mode)(2)
tBurst
4
tFcyc
7
Page erase time3
tPage
4000
tFcyc
8
Mass erase time2
tMass
20,000
tFcyc
9
10
C
Program/erase endurance4
TL to TH = –40°C to + 85°C
T = 25°C
Data retention5
tD_ret
10,000
—
—
100,000
—
—
cycles
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 is based on the intrinsic bitcell performance. 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
A.14
USB Electricals
The USB electricals for the S08USBV1 module conform to the standards documented by the Universal
Serial Bus Implementers Forum. For the most up-to-date standards, visit http://www.usb.org.
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
369
Appendix A Electrical Characteristics
If the Freescale S08USBV1 implementation has electrical characteristics that deviate from the standard or
require additional information, this space would be used to communicate that information.
Table A-16. Internal USB 3.3V Voltage Regulator Characteristics
Symbol
Unit
Min
Typ
Max
Regulator operating voltage
Vregin
V
3.9
—
5.5
VREG output
Vregout
V
3
3.3
3.6
VUSB33 input with internal
VREG disabled
Vusb33in
V
3
3.3
3.6
VREG Quiescent Current
IVRQ
mA
—
0.5
—
18.5
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 can consult Freescale applications notes such as AN2321, AN1050, AN1263, AN2764,
and AN1259 for advice and guidance specifically targeted at optimizing EMC performance.
18.5.1
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 18-8. Radiated Emissions
Parameter
Radiated emissions,
electric field
1
Symbol
VRE_TEM
Conditions
VDD = 5.0 V
TA = +25oC
Frequency
fOSC/fBUS
Level1
(Max)
0.15 – 50 MHz
7
50 – 150 MHz
11
150 – 500 MHz
500 – 1000 MHz
4 MHz crystal
20 MHz Bus
Unit
dBμV
2
–2
IEC Level
N
—
SAE Level
2
—
The reported emission level is the value of the maximum emission, rounded up to the next whole number, from among the
measured orientations in each frequency range.
MC9S08JM16 Series Data Sheet, Rev. 2
370
Freescale Semiconductor
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
371
Appendix A Electrical Characteristics
MC9S08JM16 Series Data Sheet, Rev. 2
372
Freescale Semiconductor
Appendix B
Ordering Information and Mechanical Drawings
B.1
Ordering Information
This section contains ordering numbers for MC9S08JM16 series 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
Type
MC9S08JM16
16,384
1024
MC9S08JM8
8,192
1024
48-pin QFN
44-pin LQFP
32-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 JM 16 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)
Memory size designator
Mechanical Drawings
This following pages contain mechanical specifications for MC9S08JM16 series 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.
48
QFN
GT
98ARH99048A
44
LQFP
LD
98ASS23225W
32
LQFP
LC
98ASH70029A
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor
373
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Rev. 2, 5/2008
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