Freescale MC9S08QD2VPS 8-bit hcs08 central processor unit (cpu) Datasheet

MC9S08QD4
MC9S08QD2
S9S08QD4
S9S08QD2
Data Sheet
HCS08
Microcontrollers
MC9S08QD4
Rev. 3
11/2007
freescale.com
MC9S08QD4 Series Features
8-Bit HCS08 Central Processor Unit (CPU)
•
•
•
•
•
16 MHz HCS08 CPU (central processor
unit)
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)
Support for up to 32 interrupt/reset sources
•
Peripherals
•
•
Memory
•
•
•
Flash read/program/erase over full
operating voltage and temperature
Flash size:
— MC9S08QD4/S9S08QD4: 4096 bytes
— MC9S08QD2/S9S08QD2: 2048 bytes
RAM size
— MC9S08QD4/S9S08QD4: 256 bytes
— MC9S08QD2/S9S08QD2: 128 bytes
Power-Saving Modes
•
•
•
•
Wait plus three stops
ICS — Internal clock source module (ICS)
containing a frequency-locked-loop (FLL)
controlled by internal. Precision trimming
of internal reference allows 0.2% resolution
and 2% deviation over temperature and
voltage.
System Protection
•
•
•
•
Watchdog computer operating properly
(COP) reset with option to run from
dedicated 32 kHz internal clock source or
bus clock
Low-voltage detection with reset or
interrupt
Illegal opcode detection with reset
Illegal address detection with reset
ADC — 4-channel, 10-bit analog-to-digital
converter with automatic compare
function, asynchronous clock source,
temperature sensor and internal bandgap
reference channel. ADC is hardware
triggerable using the RTI counter.
TIM1 — 2-channel timer/pulse-width
modulator; each channel can be used for
input capture, output compare, buffered
edge-aligned PWM, or buffered
center-aligned PWM
TIM2 — 1-channel timer/pulse-width
modulator; each channel can be used for
input capture, output compare, buffered
edge-aligned PWM, or buffered
center-aligned PWM
KBI — 4-pin keyboard interrupt module
with software selectable polarity on edge or
edge/level modes
Input/Output
Clock Source Options
•
Flash block protect
•
•
•
Four General-purpose input/output (I/O)
pins, one input-only pin and one
output-only pin. Outputs 10 mA each, 60
mA maximum for package.
Software selectable pullups on ports when
used as input
Software selectable slew rate control and
drive strength on ports when used as output
Internal pullup on RESET and IRQ pin to
reduce customer system cost
Development Support
•
Single-wire background debug interface
Package Options
•
•
•
8-pin SOIC package
8-pin PDIP (Only for MC9S08QD4 and
MC9S08QD2)
All package options are RoHS compliant
MC9S08QD4 Data Sheet
Covers:
MC9S08QD4
MC9S08QD2
S9S08QD4
S9S08QD2
MC9S08QD4
Rev. 3
11/2007
Revision History
To provide the most up-to-date information, the revision of our documents on the World Wide Web will
be the most current. Your printed copy may be an earlier revision. To verify you have the latest information
available, refer to:
http://freescale.com/
The following revision history table summarizes changes contained in this document.
Revision
Number
Revision
Date
1
15 Sep 06
Initial public release
2
09 Jan 07
Added MC9S08QD2 information; added “M” temperature range (–40 °C to 125 °C); updated
temperature sensor equation in the ADC chapter.
3
19 Nov. 07
Added S9S08QD4 and S9S08QD2 information for automotive applications. Revised "Accessing
(read or write) any flash control register..." to “ Writing any flash control register...” in Section 4.5.5,
“Access Errors.”
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., 2007. All rights reserved.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
6
Freescale Semiconductor
List of Chapters
Chapter 1
Device Overview ...................................................................... 17
Chapter 2
External Signal Description .................................................... 21
Chapter 3
Modes of Operation ................................................................. 27
Chapter 4
Memory Map and Register Definition .................................... 33
Chapter 5
Resets, Interrupts, and General System Control.................. 53
Chapter 6
Parallel Input/Output Control.................................................. 69
Chapter 7
Central Processor Unit (S08CPUV2) ...................................... 75
Chapter 8
Analog-to-Digital Converter (ADC10V1) ................................ 95
Chapter 9
Internal Clock Source (S08ICSV1)........................................ 123
Chapter 10
Keyboard Interrupt (S08KBIV2) ............................................ 137
Chapter 11
Timer/Pulse-Width Modulator (S08TPMV2) ......................... 145
Chapter 12
Development Support ........................................................... 161
Appendix A
Electrical Characteristics...................................................... 175
Appendix B
Ordering Information and Mechanical Drawings................ 193
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
7
Contents
Section Number
Title
Page
Chapter 1
Device Overview
1.1
1.2
1.3
Introduction .....................................................................................................................................17
Devices in the MC9S08QD4 Series ................................................................................................17
1.2.1 MCU Block Diagram ........................................................................................................19
System Clock Distribution ..............................................................................................................20
Chapter 2
External Signal Description
2.1
2.2
Device Pin Assignment ...................................................................................................................21
Recommended System Connections ...............................................................................................21
2.2.1 Power ................................................................................................................................22
2.2.2 Oscillator ...........................................................................................................................23
2.2.3 Reset (Input Only) ............................................................................................................23
2.2.4 Background / Mode Select (BKGD/MS) ..........................................................................23
2.2.5 General-Purpose I/O and Peripheral Ports ........................................................................24
Chapter 3
Modes of Operation
3.1
3.2
3.3
3.4
3.5
3.6
Introduction .....................................................................................................................................27
Features ...........................................................................................................................................27
Run Mode ........................................................................................................................................27
Active Background Mode ...............................................................................................................27
Wait Mode .......................................................................................................................................28
Stop Modes ......................................................................................................................................28
3.6.1 Stop2 Mode .......................................................................................................................29
3.6.2 Stop3 Mode .......................................................................................................................30
3.6.3 Active BDM Enabled in Stop Mode .................................................................................30
3.6.4 LVD Enabled in Stop Mode ..............................................................................................31
3.6.5 On-Chip Peripheral Modules in Stop Modes ....................................................................31
Chapter 4
Memory Map and Register Definition
4.1
4.2
4.3
4.4
4.5
MC9S08QD4 Series Memory Maps ...............................................................................................33
Reset and Interrupt Vector Assignments .........................................................................................34
Register Addresses and Bit Assignments ........................................................................................35
RAM ................................................................................................................................................38
Flash ................................................................................................................................................39
4.5.1 Features .............................................................................................................................39
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
9
4.6
4.7
4.5.2 Program and Erase Times .................................................................................................39
4.5.3 Program and Erase Command Execution .........................................................................40
4.5.4 Burst Program Execution ..................................................................................................41
4.5.5 Access Errors ....................................................................................................................43
4.5.6 Flash Block Protection ......................................................................................................44
4.5.7 Vector Redirection ............................................................................................................45
Security ............................................................................................................................................45
Flash Registers and Control Bits .....................................................................................................46
4.7.1 Flash Clock Divider Register (FCDIV) ............................................................................46
4.7.2 Flash Options Register (FOPT and NVOPT) ....................................................................48
4.7.3 Flash Configuration Register (FCNFG) ...........................................................................49
4.7.4 Flash Protection Register (FPROT and NVPROT) ..........................................................49
4.7.5 Flash Status Register (FSTAT) ..........................................................................................50
4.7.6 Flash Command Register (FCMD) ...................................................................................51
Chapter 5
Resets, Interrupts, and General System Control
5.1
5.2
5.3
5.4
5.5
5.6
5.7
5.8
Introduction .....................................................................................................................................53
Features ...........................................................................................................................................53
MCU Reset ......................................................................................................................................53
Computer Operating Properly (COP) Watchdog .............................................................................54
Interrupts .........................................................................................................................................55
5.5.1 Interrupt Stack Frame .......................................................................................................56
5.5.2 External Interrupt Request (IRQ) Pin ...............................................................................56
5.5.3 Interrupt Vectors, Sources, and Local Masks ...................................................................57
Low-Voltage Detect (LVD) System ................................................................................................58
5.6.1 Power-On Reset Operation ...............................................................................................59
5.6.2 LVD Reset Operation ........................................................................................................59
5.6.3 LVD Interrupt Operation ...................................................................................................59
5.6.4 Low-Voltage Warning (LVW) ...........................................................................................59
Real-Time Interrupt (RTI) ...............................................................................................................59
Reset, Interrupt, and System Control Registers and Control Bits ...................................................60
5.8.1 Interrupt Pin Request Status and Control Register (IRQSC) ............................................60
5.8.2 System Reset Status Register (SRS) .................................................................................61
5.8.3 System Background Debug Force Reset Register (SBDFR) ............................................62
5.8.4 System Options Register 1 (SOPT1) ................................................................................63
5.8.5 System Options Register 2 (SOPT2) ................................................................................64
5.8.6 System Device Identification Register (SDIDH, SDIDL) ................................................64
5.8.7 System Real-Time Interrupt Status and Control Register (SRTISC) ................................65
5.8.8 System Power Management Status and Control 1 Register (SPMSC1) ...........................66
5.8.9 System Power Management Status and Control 2 Register (SPMSC2) ...........................67
Chapter 6
Parallel Input/Output Control
6.1
Port Data and Data Direction ..........................................................................................................69
MC9S08QD4 Series MCU Data Sheet, Rev. 3
10
Freescale Semiconductor
6.2
6.3
6.4
Pin Control — Pullup, Slew Rate and Drive Strength ....................................................................70
Pin Behavior in Stop Modes ............................................................................................................70
Parallel I/O Registers ......................................................................................................................71
6.4.1 Port A Registers ................................................................................................................71
6.4.2 Port A Control Registers ...................................................................................................72
Chapter 7
Central Processor Unit (S08CPUV2)
7.1
7.2
7.3
7.4
7.5
Introduction .....................................................................................................................................75
7.1.1 Features .............................................................................................................................75
Programmer’s Model and CPU Registers .......................................................................................76
7.2.1 Accumulator (A) ...............................................................................................................76
7.2.2 Index Register (H:X) ........................................................................................................76
7.2.3 Stack Pointer (SP) .............................................................................................................77
7.2.4 Program Counter (PC) ......................................................................................................77
7.2.5 Condition Code Register (CCR) .......................................................................................77
Addressing Modes ...........................................................................................................................79
7.3.1 Inherent Addressing Mode (INH) .....................................................................................79
7.3.2 Relative Addressing Mode (REL) ....................................................................................79
7.3.3 Immediate Addressing Mode (IMM) ................................................................................79
7.3.4 Direct Addressing Mode (DIR) ........................................................................................79
7.3.5 Extended Addressing Mode (EXT) ..................................................................................80
7.3.6 Indexed Addressing Mode ................................................................................................80
Special Operations ...........................................................................................................................81
7.4.1 Reset Sequence .................................................................................................................81
7.4.2 Interrupt Sequence ............................................................................................................81
7.4.3 Wait Mode Operation ........................................................................................................82
7.4.4 Stop Mode Operation ........................................................................................................82
7.4.5 BGND Instruction .............................................................................................................83
HCS08 Instruction Set Summary ....................................................................................................84
Chapter 8
Analog-to-Digital Converter (ADC10V1)
8.1
8.2
8.3
Introduction .....................................................................................................................................95
8.1.1 Module Configurations .....................................................................................................96
8.1.2 Features .............................................................................................................................99
8.1.3 Block Diagram ..................................................................................................................99
External Signal Description ..........................................................................................................100
8.2.1 Analog Power (VDDAD) ..................................................................................................101
8.2.2 Analog Ground (VSSAD) .................................................................................................101
8.2.3 Voltage Reference High (VREFH) ...................................................................................101
8.2.4 Voltage Reference Low (VREFL) ....................................................................................101
8.2.5 Analog Channel Inputs (ADx) ........................................................................................101
Register Definition ........................................................................................................................101
8.3.1 Status and Control Register 1 (ADCSC1) ......................................................................101
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
11
8.4
8.5
8.6
8.3.2 Status and Control Register 2 (ADCSC2) ......................................................................103
8.3.3 Data Result High Register (ADCRH) .............................................................................104
8.3.4 Data Result Low Register (ADCRL) ..............................................................................104
8.3.5 Compare Value High Register (ADCCVH) ....................................................................105
8.3.6 Compare Value Low Register (ADCCVL) .....................................................................105
8.3.7 Configuration Register (ADCCFG) ................................................................................105
8.3.8 Pin Control 1 Register (APCTL1) ..................................................................................107
8.3.9 Pin Control 2 Register (APCTL2) ..................................................................................108
8.3.10 Pin Control 3 Register (APCTL3) ..................................................................................109
Functional Description ..................................................................................................................110
8.4.1 Clock Select and Divide Control ....................................................................................110
8.4.2 Input Select and Pin Control ...........................................................................................111
8.4.3 Hardware Trigger ............................................................................................................ 111
8.4.4 Conversion Control ......................................................................................................... 111
8.4.5 Automatic Compare Function .........................................................................................114
8.4.6 MCU Wait Mode Operation ............................................................................................114
8.4.7 MCU Stop3 Mode Operation ..........................................................................................114
8.4.8 MCU Stop1 and Stop2 Mode Operation .........................................................................115
Initialization Information ..............................................................................................................115
8.5.1 ADC Module Initialization Example .............................................................................115
Application Information ................................................................................................................117
8.6.1 External Pins and Routing ..............................................................................................117
8.6.2 Sources of Error ..............................................................................................................119
Chapter 9
Internal Clock Source (S08ICSV1)
9.1
9.2
9.3
9.4
Introduction ...................................................................................................................................123
9.1.1 ICS Configuration Information .......................................................................................123
9.1.2 Features ...........................................................................................................................125
9.1.3 Modes of Operation ........................................................................................................125
9.1.4 Block Diagram ................................................................................................................126
External Signal Description ..........................................................................................................127
Register Definition ........................................................................................................................127
9.3.1 ICS Control Register 1 (ICSC1) .....................................................................................127
9.3.2 ICS Control Register 2 (ICSC2) .....................................................................................128
9.3.3 ICS Trim Register (ICSTRM) .........................................................................................129
9.3.4 ICS Status and Control (ICSSC) .....................................................................................129
Functional Description ..................................................................................................................130
9.4.1 Operational Modes ..........................................................................................................130
9.4.2 Mode Switching ..............................................................................................................132
9.4.3 Bus Frequency Divider ...................................................................................................132
9.4.4 Low Power Bit Usage .....................................................................................................133
9.4.5 Internal Reference Clock ................................................................................................133
9.4.6 Optional External Reference Clock ................................................................................133
9.4.7 Fixed Frequency Clock ...................................................................................................134
MC9S08QD4 Series MCU Data Sheet, Rev. 3
12
Freescale Semiconductor
9.5
Module Initialization ....................................................................................................................134
9.5.1 ICS Module Initialization Sequence ...............................................................................134
Chapter 10
Keyboard Interrupt (S08KBIV2)
10.1 Introduction ...................................................................................................................................137
10.1.1 Features ...........................................................................................................................139
10.1.2 Modes of Operation ........................................................................................................139
10.1.3 Block Diagram ................................................................................................................139
10.2 External Signal Description ..........................................................................................................140
10.3 Register Definition ........................................................................................................................140
10.3.1 KBI Status and Control Register (KBISC) .....................................................................140
10.3.2 KBI Pin Enable Register (KBIPE) ..................................................................................141
10.3.3 KBI Edge Select Register (KBIES) ................................................................................141
10.4 Functional Description ..................................................................................................................142
10.4.1 Edge Only Sensitivity .....................................................................................................142
10.4.2 Edge and Level Sensitivity .............................................................................................142
10.4.3 KBI Pullup/Pulldown Resistors ......................................................................................143
10.4.4 KBI Initialization ............................................................................................................143
Chapter 11
Timer/Pulse-Width Modulator (S08TPMV2)
11.1 Introduction ...................................................................................................................................145
11.1.1 TPM2 Configuration Information ...................................................................................145
11.1.2 TCLK1 and TCLK2 Configuration Information ............................................................145
11.1.3 Features ...........................................................................................................................147
11.1.4 Block Diagram ................................................................................................................147
11.2 External Signal Description ..........................................................................................................149
11.2.1 External TPM Clock Sources .........................................................................................149
11.2.2 TPMxCHn — TPMx Channel n I/O Pins .......................................................................149
11.3 Register Definition ........................................................................................................................149
11.3.1 Timer Status and Control Register (TPMxSC) ...............................................................150
11.3.2 Timer Counter Registers (TPMxCNTH:TPMxCNTL) ...................................................151
11.3.3 Timer Counter Modulo Registers (TPMxMODH:TPMxMODL) ..................................152
11.3.4 Timer Channel n Status and Control Register (TPMxCnSC) .........................................153
11.3.5 Timer Channel Value Registers (TPMxCnVH:TPMxCnVL) .........................................154
11.4 Functional Description ..................................................................................................................155
11.4.1 Counter ............................................................................................................................155
11.4.2 Channel Mode Selection .................................................................................................156
11.4.3 Center-Aligned PWM Mode ...........................................................................................158
11.5 TPM Interrupts ..............................................................................................................................159
11.5.1 Clearing Timer Interrupt Flags .......................................................................................159
11.5.2 Timer Overflow Interrupt Description ............................................................................159
11.5.3 Channel Event Interrupt Description ..............................................................................160
11.5.4 PWM End-of-Duty-Cycle Events ...................................................................................160
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
13
Chapter 12
Development Support
12.1 Introduction ...................................................................................................................................161
12.1.1 Forcing Active Background ............................................................................................161
12.1.2 Module Configuration .....................................................................................................161
12.1.3 Features ...........................................................................................................................162
12.2 Background Debug Controller (BDC) ..........................................................................................162
12.2.1 BKGD Pin Description ...................................................................................................163
12.2.2 Communication Details ..................................................................................................163
12.2.3 BDC Commands .............................................................................................................166
12.2.4 BDC Hardware Breakpoint .............................................................................................169
12.3 Register Definition ........................................................................................................................169
12.3.1 BDC Registers and Control Bits .....................................................................................170
12.3.2 System Background Debug Force Reset Register (SBDFR) ..........................................172
Appendix A
Electrical Characteristics
A.1
A.2
A.3
A.4
A.5
A.6
A.7
A.8
Introduction ...................................................................................................................................175
Absolute Maximum Ratings ..........................................................................................................175
Thermal Characteristics .................................................................................................................176
ESD Protection and Latch-Up Immunity ......................................................................................177
DC Characteristics .........................................................................................................................177
Supply Current Characteristics ......................................................................................................184
Internal Clock Source Characteristics ...........................................................................................186
AC Characteristics .........................................................................................................................188
A.8.1 Control Timing ...............................................................................................................188
A.8.2 Timer/PWM (TPM) Module Timing ..............................................................................189
A.9 ADC Characteristics ......................................................................................................................190
A.10 Flash Specifications .......................................................................................................................191
Appendix B
Ordering Information and Mechanical Drawings
B.1 Ordering Information ....................................................................................................................193
B.1.1 Device Numbering Scheme ............................................................................................193
B.2 Mechanical Drawings ....................................................................................................................194
MC9S08QD4 Series MCU Data Sheet, Rev. 3
14
Freescale Semiconductor
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
15
Chapter 1
Device Overview
1.1
Introduction
MC9S08QD4 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.
1.2
Devices in the MC9S08QD4 Series
This data sheet covers:
• MC9S08QD4
• MC9S08QD2
• S9S08QD4
• S9S08QD2
•
•
NOTE
The MC9S08QD4 and MC9S08QD2 devices are qualified for, and are
intended to be used in, consumer and industrial applications.
The S9S08QD4 and S9S08QD2 devices are qualified for, and are
intended to be used in, automotive applications.
Table 1-1 summarizes the features available in the MCUs.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
17
Chapter 1 Device Overview
Table 1-1. Features by MCU and Package
Consumer and Industrial Devices
Feature
MC9S08QD4
MC9S08QD2
Flash
4 KB
2 KB
RAM
256 B
128 B
ADC
4-ch, 10-bit
Bus speed
8 MHz at 5 V
Operating voltage
2.7 to 5.5 V
16-bit Timer
One 1-ch; one 2-ch
GPIO
Four I/O; one input-only; one output-only
LVI
Yes
Package options
8-pin PDIP; 8-pin NB SOIC
Consumer & Industrial Qualified
yes
yes
Automotive Qualified
no
no
Automotive Devices
Feature
S9S08QD4
S9S08QD2
Flash
4 KB
2 KB
RAM
256 B
128 B
ADC
4-ch, 10-bit
Bus speed
8 MHz at 5 V
Operating voltage
2.7 to 5.5 V
16-bit Timer
One 1-ch; one 2-ch
GPIO
Four I/O; one input-only; one output-only
LVI
Yes
Package options
8-pin NB SOIC
Consumer & Industrial Qualified
no
no
Automotive Qualified
yes
yes
MC9S08QD4 Series MCU Data Sheet, Rev. 3
18
Freescale Semiconductor
Chapter 1 Device Overview
1.2.1
MCU Block Diagram
BKGD/MS
IRQ
HCS08 CORE
BDC
4-BIT KEYBOARD
INTERRUPT MODULE (KBI)
HCS08 SYSTEM CONTROL
RESETS AND INTERRUPTS
MODES OF OPERATION
POWER MANAGEMENT
RTI
COP
IRQ
LVD
USER FLASH
4096 / 2048 BYTES
4
TPM2CH0
1-CH 16-BIT TIMER/PWM
MODULE (TPM2)
TCLK2
2-CH 16-BIT TIMER/PWM
MODULE (TPM1)
TPM1CH0
TPM1CH1
TCLK1
10-BIT
ANALOG-TO-DIGITAL
CONVERTER (ADC)
PORT A
CPU
PTA5/TPM2CH0I/IRQ/RESET
PTA4/TPM2CH0O/BKGD/MS
PTA3/KBI1P3/TCLK2/ADC1P3
PTA2/KBI1P2/TCLK1/ADC1P2
PTA1/KBI1P1/TPM1CH1/ADC1P1
PTA0/KBI1P0/TPM1CH0/ADC1P0
4
USER RAM
256 / 128 BYTES
16 MHz INTERNAL CLOCK
SOURCE (ICS)
VSS
VDD
VOLTAGE REGULATOR
VDDA
VSSA
VREFH
VREFL
NOTES:
1 Port pins are software configurable with pullup device if input port.
2
Port pins are software configurable for output drive strength.
3 Port pins are software configurable for output slew rate control.
4 IRQ contains a software configurable (IRQPDD) pullup/pulldown device if PTA5 enabled as IRQ pin function (IRQPE = 1).
5
RESET contains integrated pullup device if PTA5 enabled as reset pin function (RSTPE = 1).
6 PTA5 does not contain a clamp diode to V
DD and must not be driven above VDD. The voltage measured on this pin when
internal pullup is enabled may be as low as VDD – 0.7 V. The internal gates connected to this pin are pulled to VDD.
7 PTA4 contains integrated pullup device if BKGD enabled (BKGDPE = 1).
8 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.
Figure 1-1. MC9S08QD4 Series Block Diagram
Table 1-2 provides the functional versions of the on-chip modules.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
19
Chapter 1 Device Overview
Table 1-2. Versions of On-Chip Modules
Module
Version
Analog-to-Digital Converter
1.3
(ADC)
1
Central Processing Unit
(CPU)
2
Internal Clock Source
(ICS)
1
Keyboard Interrupt
(KBI)
2
Timer Pulse-Width Modulator
(TPM)
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
function. All memory mapped registers associated with the modules are clocked with BUSCLK.
TCLK1
TCLK2
TPM1
TPM2
SYSTEM CONTROL LOGIC
RTI
ICSIRCLK
ICSFFCLK
ICS
COP
FIXED FREQ CLOCK (XCLK)
÷2
ICSOUT
÷2
BUSCLK
CPU
ICSLCLK1
BDC
FLASH3
ADC2
1
ICSLCLK is the alternate BDC clock source for the MC9S08QD4 series.
2
ADC has min. and max frequency requirements. See ADC chapter and Appendix A, “Electrical Characteristics.”
3 Flash has frequency requirements for program and erase operation.See Appendix A, “Electrical Characteristics.”
Figure 1-2. System Clock Distribution Diagram
MC9S08QD4 Series MCU Data Sheet, Rev. 3
20
Freescale Semiconductor
Chapter 2
External Signal Description
This chapter describes signals that connect to package pins. It includes pinout diagrams, table of signal
properties, and detailed discussions of signals.
2.1
Device Pin Assignment
Figure 2-1 shows the pin assignments for the 8-pin packages.
PTA5/TPM2CH0I/IRQ/RESET
1
8
PTA0/KBI1P0/TPM1CH0/ADC1P0
PTA4/TPM2CH0O/BKGD/MS
2
7
PTA1/KBI1P1/TPM1CH1/ADC1P1
VDD
3
6
PTA2/KBI1P2/TCLK1/ADC1P2
VSS
4
5
PTA3/KBI1P3/TCLK2/ADC1P3
Figure 2-1. 8-Pin Packages
2.2
Recommended System Connections
Figure 2-2 shows pin connections that are common to almost all MC9S08QD4 series application systems.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
21
Chapter 2 External Signal Description
MC9S08QD4
VDD
SYSTEM
POWER
+
5V
CBLK
+
10 μF
PTA0/KBI1P0/TPM1CH0/ADC1P0
VDD
CBY
PTA1/KBI1P1/TPM1CH1/ADC1P1
PORT
A
0.1 μF
VSS
PTA2/KBI1P2/TCLK1/ADC1P2
PTA3/KBI1P3/TCLK2/ADC1P3
PTA4/TPM2CH0O/BKGD/MS
PTA5/TPM2CH0I/IRQ/RESET
I/O AND
PERIPHERAL
INTERFACE TO
APPLICATION
SYSTEM
BACKGROUND HEADER
BKGD
VDD
NOTE 1
OPTIONAL
MANUAL
RESET
ASYNCHRONOUS
INTERRUPT
INPUT
RESET
IRQ
NOTE 2
NOTES:
1. RESET pin can only be used to reset into user mode, you can not enter BDM using RESET pin. BDM can
be entered by holding MS low during POR or writing a 1 to BDFR in SBDFR with MS low after issuing BDM
command.
2. IRQ has optional internal pullup/pulldown device
Figure 2-2. Basic System Connections
2.2.1
Power
VDD and VSS are the primary power supply pins for the MCU. This voltage source supplies power to all
I/O buffer circuitry, the ADC module, 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: a bulk electrolytic
capacitor, such as a 10μF tantalum capacitor, to provide bulk charge storage for the overall system, and a
bypass capacitor, such as a 0.1μF ceramic capacitor, located as near to the MCU power pins as practical
to suppress high-frequency noise.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
22
Freescale Semiconductor
Chapter 2 External Signal Description
2.2.2
Oscillator
Out of reset the MCU uses an internally generated clock provided by the internal clock source (ICS)
module. The internal frequency is nominally 16 MHz and the default ICS settings will provide for a 4 MHz
bus out of reset. For more information on the ICS, see the Internal Clock Source chapter.
2.2.3
Reset (Input Only)
After a power-on reset (POR) into user mode, the PTA5/TPM2CH0I/IRQ/RESET pin defaults to a
general-purpose input port pin, PTA5. Setting RSTPE in SOPT1 configures the pin to be the RESET input
pin. Once configured as RESET, the pin will remain RESET until the next POR. The RESET pin can be
used to reset the MCU from an external source when the pin is driven low. When enabled as the RESET
pin (RSTPE = 1), an internal pullup device is automatically enabled.
After a POR into active background mode, the PTA5/TPM2CH0I/IRQ/RESET pin defaults to the RESET
pin.
When TPM2 is configured for input capture, the pin will be the input capture pin TPM2CH0I.
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 RESET pin may be as low
as VDD – 0.7 V. The internal gates connected to this pin are pulled to VDD.
2.2.4
Background / Mode Select (BKGD/MS)
During a power-on-reset (POR) or background debug force reset (see Section 5.8.3, “System Background
Debug Force Reset Register (SBDFR)” for more information), the PTA4/TPM2CH0O/BKGD/MS pin
functions as a mode select pin. Immediately after any reset, the pin functions as the background pin and
can be used for background debug communication. When enabled as the BKGD/MS pin (BKGDPE = 1),
an internal pullup device is automatically enabled.
The background debug communication function is enabled when BKGDPE in SOPT1 is set. BKGDPE is
set following any reset of the MCU and must be cleared to use the PTA4/TPM2CH0O/BKGD/MS pins
alternative pin functions.
If nothing is connected to this pin, the MCU will enter normal operating mode at the rising edge of the
internal reset after a POR or force BDC reset. If a debug system is connected to the 6-pin standard
background debug header, it can hold BKGD/MS low during a POR or immediately after issuing a
background debug force reset, which will force 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 maximum bus clock rate, so there must never be any significant capacitance
connected to the BKGD/MS pin that could interfere with background serial communications.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
23
Chapter 2 External Signal Description
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.
2.2.5
General-Purpose I/O and Peripheral Ports
The MC9S08QD4 series of MCUs support up to 4 general-purpose I/O pins, 1 input-only pin and 1
output-only pin, which are shared with on-chip peripheral functions (timers, serial I/O, ADC, keyboard
interrupts, etc.). On each of the MC9S08QD4 series devices there is one input-only and one output-only
port pin.
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 Control.” For information about how and when on-chip peripheral systems use these pins,
see the appropriate chapter referenced in Table 2-1.
Immediately after reset, all pins that are not output-only are configured as high-impedance,
general-purpose inputs with internal pullup devices disabled. After reset, the output-only port function is
not enabled but is configured for low output drive strength with slew rate control enabled. The PTA4 pin
defaults to BKGD/MS on any reset.
NOTE
To avoid extra current drain from floating input pins, the reset initialization
routine in the application program must either enable on-chip pullup devices
or change the direction of unused pins to outputs so the pins do not float.
2.2.5.1
Pin Control Registers
To select drive strength or enable slew rate control or pullup devices, the user writes to the appropriate pin
control register located in the high-page register block of the memory map. The pin control registers
operate independently of the parallel I/O registers and allow control of a port on an individual pin basis.
2.2.5.1.1
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.
The KBI module and IRQ function when enabled for rising edge detection causes an enabled internal pull
device to be configured as a pulldown.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
24
Freescale Semiconductor
Chapter 2 External Signal Description
2.2.5.2
Output Slew Rate Control
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 that are configured as inputs.
2.2.5.3
Output Drive Strength Select
An output pin can be selected to have high output drive strength by setting the corresponding bit in one of
the drive strength select registers (PTxDSn). When high drive is selected, a pin is capable of sourcing and
sinking greater current. Even though every I/O pin can be selected as high drive, the user must ensure that
the total current source and sink limits for the chip are not exceeded. Drive strength selection is intended
to affect the DC behavior of I/O pins. However, the AC behavior is also affected. High drive allows a pin
to drive a greater load with the same switching speed as a low drive enabled pin into a smaller load.
Because of this, the EMC emissions may be affected by enabling pins as high drive.
Table 2-1. Pin Sharing Priority
Lowest <- Pin Function Priority -> Highest
Port Pins
PTA0
PTA1
PTA2
PTA3
PTA4
PTA52
Alternative
Function
KBI1P0
KBI1P1
KBI1P2
KBI1P3
TPM2CH0O
TPM2CH0I
Alternative
Function
TPM1CH0
TPM1CH1
TCLK1
TCLK2
BKGD/MS
IRQ
Reference1
Alternative
Function
ADC1P03
ADC1P13
ADC1P23
ADC1P33
RESET
KBI1, ADC1, and TPM1 Chapters
KBI1, ADC1, and TPM1 Chapters
KBI1, ADC1, and TPM1 Chapters
KBI1, ADC1, and TPM2 Chapters
TPM2 Chapters
IRQ4, and TPM2 Chapters
1
See the module section listed for information on modules that share these pins.
Pin does not contain a clamp diode to VDD and must not be driven above VDD. The voltage measured on this
pin when internal pullup is enabled may be as low as VDD – 0.7 V. The internal gates connected to this pin are
pulled to VDD.
3 If both of these analog modules are enabled both will have access to the pin.
4 See Section 5.8, “Reset, Interrupt, and System Control Registers and Control Bits,” for information on
configuring the IRQ module.
2
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
25
Chapter 2 External Signal Description
MC9S08QD4 Series MCU Data Sheet, Rev. 3
26
Freescale Semiconductor
Chapter 3
Modes of Operation
3.1
Introduction
The operating modes of the MC9S08QD4 series are described in this chapter. Entry into each mode, exit
from each mode, and functionality while in each of the modes are described.
3.2
•
•
•
3.3
Features
Active background mode for code development
Wait mode:
— CPU shuts down to conserve power
— System clocks running
— Full voltage regulation maintained
Stop modes:
— CPU and bus clocks stopped
— Stop2 — Partial power down of internal circuits, RAM contents retained
— Stop3 — All internal circuits powered for fast recovery
Run Mode
This is the normal operating mode for the MC9S08QD4 series. This mode is selected when the BKGD/MS
pin is high at the rising edge of reset. In this mode, the CPU executes code from internal memory with
execution beginning at the address fetched from memory at 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 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 at the rising edge of reset
• When a BACKGROUND command is received through the BKGD pin
• When a BGND instruction is executed
• When encountering a BDC breakpoint
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
27
Chapter 3 Modes of Operation
After entering active background mode, the CPU is held in a suspended state waiting for serial background
commands rather than executing instructions from the user’s application program.
Background commands are of two types:
• Non-intrusive commands, defined as commands that can be issued while the user program is
running. Non-intrusive commands can be issued through the BKGD pin while the MCU is in run
mode; non-intrusive commands can also be executed when the MCU is in the active background
mode. Non-intrusive commands include:
— Memory access commands
— Memory-access-with-status commands
— BDC register access commands
— The BACKGROUND command
• Active background commands, which can only be executed while the MCU is in active background
mode. Active background commands include commands to:
— Read or write CPU registers
— Trace one user program instruction at a time
— Leave active background mode to return to the user’s application program (GO)
The active background mode is used to program a bootloader or user application program into the flash
program memory before the MCU is operated in run mode for the first time. When MC9S08QD4 series
devices are shipped from the Freescale Semiconductor factory, the flash program memory is erased by
default unless specifically noted, so no program can be executed in run mode until the flash memory is
initially programmed. The active background mode can also be used to erase and reprogram the flash
memory after it has been previously programmed.
For additional information about the active background mode, refer to Chapter 12, “Development
Support.”
3.5
Wait Mode
Wait mode is entered by executing a WAIT instruction. Upon execution of the WAIT instruction, the CPU
enters a low-power state in which it is not clocked. The I bit in CCR is cleared when the CPU enters the
wait mode, enabling interrupts. When an interrupt request occurs, the CPU exits the wait mode and
resumes processing, beginning with the stacking operations leading to the interrupt service routine.
While the MCU is in wait mode, there are some restrictions on which background debug commands can
be used. Only the BACKGROUND command and memory-access-with-status commands are available
when the MCU is in wait mode. The memory-access-with-status commands do not allow memory access,
but they report an error indicating that the MCU is in either stop or wait mode. The BACKGROUND
command can be used to wake the MCU from wait mode and enter active background mode.
3.6
Stop Modes
One of two stop modes is entered upon execution of a STOP instruction when the STOPE bit in the system
option register is set. In both stop modes, all internal clocks are halted. If the STOPE bit is not set when
MC9S08QD4 Series MCU Data Sheet, Rev. 3
28
Freescale Semiconductor
Chapter 3 Modes of Operation
the CPU executes a STOP instruction, the MCU will not enter either of the stop modes and an illegal
opcode reset is forced. The stop modes are selected by setting the appropriate bits in SPMSC2.
HCS08 devices that are designed for low voltage operation (1.8V to 3.6V) also include stop1 mode. The
MC9S08QD4 series does not include stop1 mode.
Table 3-1 summarizes the behavior of the MCU in each of the stop modes.
Table 3-1. Stop Mode Behavior
1
Mode
PPDC
CPU, Digital
Peripherals,
Flash
RAM
ICS
ADC1
Regulator
I/O Pins
RTI
Stop2
1
Off
Standby
Off
Disabled
Standby
States held
Optionally on
Stop3
0
Standby
Standby
Off1
Optionally on
Standby
States held
Optionally on
ICS can be configured to run in stop3. Please see the ICS registers.
3.6.1
Stop2 Mode
The stop2 mode provides very low standby power consumption and maintains the contents of RAM and
the current state of all of the I/O pins. To enter stop2, the user must execute a STOP instruction with stop2
selected (PPDC = 1) and stop mode enabled (STOPE = 1). In addition, the LVD must not be enabled to
operate in stop (LVDSE = 0 or LVDE = 0). If the LVD is enabled in stop, then the MCU enters stop3 upon
the execution of the STOP instruction regardless of the state of PPDC.
Before entering stop2 mode, the user must save the contents of the I/O port registers, as well as any other
memory-mapped registers which they want to restore after exit of stop2, to locations in RAM. Upon exit
of stop2, these values can be restored by user software before pin latches are opened.
When the MCU is in stop2 mode, all internal circuits that are powered from the voltage regulator are turned
off, except for the RAM. The voltage regulator is in a low-power standby state, as is the ADC. Upon entry
into stop2, the states of the I/O pins are latched. The states are held while in stop2 mode and after exiting
stop2 mode until a logic 1 is written to PPDACK in SPMSC2.
Exit from stop2 is done by asserting either of the wake-up pins: RESET or IRQ, or by an RTI interrupt.
IRQ is always an active low input when the MCU is in stop2, regardless of how it was configured before
entering stop2.
NOTE
Although this IRQ pin is automatically configured as active low input, the
pullup associated with the IRQ pin is not automatically enabled. Therefore,
if an external pullup is not used, the internal pullup must be enabled by
setting IRQPE in IRQSC.
Upon wake-up from stop2 mode, the MCU will start up as from a power-on reset (POR) except pin states
remain latched. The CPU will take the reset vector. The system and all peripherals will be in their default
reset states and must be initialized.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
29
Chapter 3 Modes of Operation
After waking up from stop2, the PPDF bit in SPMSC2 is set. This flag may be used to direct user code to
go to a stop2 recovery routine. PPDF remains set and the I/O pin states remain latched until a logic 1 is
written to PPDACK in SPMSC2.
To maintain I/O state for pins that were configured as general-purpose I/O, the user must restore the
contents of the I/O port registers, which have been saved in RAM, to the port registers before writing to
the PPDACK bit. If the port registers are not restored from RAM before writing to PPDACK, then the
register bits will assume their reset states when the I/O pin latches are opened and the I/O pins will switch
to their reset states.
For pins that were configured as peripheral I/O, the user must reconfigure the peripheral module that
interfaces to the pin before writing to the PPDACK bit. If the peripheral module is not enabled before
writing to PPDACK, the pins will be controlled by their associated port control registers when the I/O
latches are opened.
3.6.2
Stop3 Mode
Stop3 mode is entered by executing a STOP instruction under the conditions as shown in Table 3-1. The
states of all of the internal registers and logic, RAM contents, and I/O pin states are maintained.
Stop3 can be exited by asserting RESET, or by an interrupt from one of the following sources: the real-time
interrupt (RTI), LVD, ADC, IRQ, or the KBI.
If stop3 is exited by means of the RESET pin, then the MCU is reset and operation will resume after taking
the reset vector. Exit by means of one of the internal interrupt sources results in the MCU taking the
appropriate interrupt vector.
3.6.3
Active BDM Enabled in Stop Mode
Entry into the active background mode from run mode is enabled if the ENBDM bit in BDCSCR is set.
This register is described in Chapter 12, “Development Support,” of this data sheet. If ENBDM is set when
the CPU executes a STOP instruction, the system clocks to the background debug logic remain active
when the MCU enters stop mode so background debug communication is still possible. In addition, the
voltage regulator does not enter its low-power standby state but maintains full internal regulation. If the
user attempts to enter stop2 with ENBDM set, the MCU will instead enter stop3.
Most background commands are not available in stop mode. The memory-access-with-status commands
do not allow memory access, but they report an error indicating that the MCU is in either stop or wait
mode. The BACKGROUND command can be used to wake the MCU from stop and enter active
background mode if the ENBDM bit is set. After entering background debug mode, all background
commands are available. Table 3-2 summarizes the behavior of the MCU in stop when entry into the
background debug mode is enabled.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
30
Freescale Semiconductor
Chapter 3 Modes of Operation
Table 3-2. BDM Enabled Stop Mode Behavior
Mode
PPDC
CPU, Digital
Peripherals,
Flash
RAM
ICS
ADC1
Regulator
I/O Pins
RTI
Stop3
0
Standby
Standby
Active
Optionally on
Active
States held
Optionally on
3.6.4
LVD Enabled in Stop Mode
The LVD system is capable of generating either an interrupt or a reset when the supply voltage drops below
the LVD voltage. If the LVD is enabled in stop by setting the LVDE and the LVDSE bits, then the voltage
regulator remains active during stop mode. If the user attempts to enter stop2 with the LVD enabled for
stop, the MCU will instead enter stop3. Table 3-3 summarizes the behavior of the MCU in stop when the
LVD is enabled.
Table 3-3. LVD Enabled Stop Mode Behavior
1
Mode
PPDC
CPU, Digital
Peripherals,
Flash
RAM
ICS
ADC1
Regulator
I/O Pins
RTI
Stop3
0
Standby
Standby
Off1
Optionally on
Active
States held
Optionally on
ICS can be configured to run in stop3. Please see the ICS registers.
3.6.5
On-Chip Peripheral Modules in Stop Modes
When the MCU enters any stop mode, system clocks to the internal peripheral modules are stopped. Even
in the exception case (ENBDM = 1), where clocks to the background debug logic continue to operate,
clocks to the peripheral systems are halted to reduce power consumption. Refer to Section 3.6.1, “Stop2
Mode,” and Section 3.6.2, “Stop3 Mode,” for specific information on system behavior in stop modes.
Table 3-4. Stop Mode Behavior
Mode
Peripheral
Stop2
CPU
Off
Standby
RAM
Standby
Standby
Flash
Off
Standby
Parallel Port Registers
Off
Standby
ADC1
Off
Optionally On1
ICS
Off
Standby
TPM1 & TPM2
Voltage Regulator
I/O Pins
1
Stop3
Off
Standby
Standby
Standby
States Held
States Held
Requires the asynchronous ADC clock and LVD to be enabled, else in standby.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
31
Chapter 3 Modes of Operation
MC9S08QD4 Series MCU Data Sheet, Rev. 3
32
Freescale Semiconductor
Chapter 4
Memory Map and Register Definition
4.1
MC9S08QD4 Series Memory Maps
As shown in Figure 4-1, on-chip memory in the MC9S08QD4 series MCU consists of RAM, flash
program memory for non-volatile data storage, and I/O and control/status registers. The registers are
divided into these groups:
• Direct-page registers (0x0000 through 0x005F)
• High-page registers (0x1800 through 0x184F)
• Non-volatile registers (0xFFB0 through 0xFFBF)
0x0000
0x005F
0x0060
0x015F
0x0160
0x17FF
0x1800
DIRECT PAGE REGISTERS
RAM
256 BYTES
UNIMPLEMENTED
5,792 BYTES
0x0000
0x005F
0x0060–0x07F
DIRECT PAGE REGISTERS
RESERVED — 32 BYTES
0x0080–0x0FF
RAM — 128 BYTES
0x0100–0x015F
RESERVED — 96 BYTES
0x17FF
0x1800
UNIMPLEMENTED
5,792 BYTES
HIGH PAGE REGISTERS
HIGH PAGE REGISTERS
0x184F
0x1850
0x184F
0x1850
UNIMPLEMENTED
UNIMPLEMENTED
55,216 BYTES
55,216 BYTES
0xEFFF
0xF000
0xEFFF
0xF000
FLASH
4096 BYTES
0xF7FF
0xF800
0xFFFF
0xFFFF
MC9S08QD4
RESERVED — 2048 BYTES
FLASH
2048 BYTES
MC9S08QD2
Figure 4-1. MC9S08QD4 Series Memory Maps
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
33
Chapter 4 Memory Map and Register Definition
4.2
Reset and Interrupt Vector Assignments
Table 4-1 shows address assignments for reset and interrupt vectors. The vector names shown in this table
are the labels used in the Freescale Semiconductor-provided equate file for the MC9S08QD4 series.
Table 4-1. Reset and Interrupt Vectors
Address
(High/Low)
0xFFC0:FFC1
Vector
Vector Name
Unused Vector Space
(available for user program)
0xFFCE:FFCF
0xFFD0:FFD1
RTI
Vrti
0xFFD2:FFD3
Reserved
—
0xFFD4:FFD5
Reserved
—
0xFFD6:FFD7
Reserved
—
0xFFD8:FFD9
ADC1 Conversion
Vadc1
0xFFDA:FFDB
KBI Interrupt
Vkeyboard1
0xFFDC:FFDD
Reserved
—
0xFFDE:FFDF
Reserved
—
0xFFE0:FFE1
Reserved
—
0xFFE2:FFE3
Reserved
—
0xFFE4:FFE5
Reserved
—
0xFFE6:FFE7
Reserved
—
0xFFE8:FFE9
Reserved
—
0xFFEA:FFEB
TPM2 Overflow
Vtpm2ovf
0xFFEC:FFED
Reserved
—
0xFFEE:FFEF
TPM2 Channel 0
Vtpm2ch0
0xFFF0:FFF1
TPM1 Overflow
Vtpm1ovf
0xFFF2:FFF3
TPM1 Channel 1
Vtpm1ch1
0xFFF4:FFF5
TPM1 Channel 0
Vtpm1ch0
0xFFF6:FFF7
Reserved
—
0xFFF8:FFF9
IRQ
IRQ
0xFFFA:FFFB
Low Voltage Detect
Vlvd
0xFFFC:FFFD
SWI
Vswi
0xFFFE:FFFF
Reset
Vreset
MC9S08QD4 Series MCU Data Sheet, Rev. 3
34
Freescale Semiconductor
Chapter 4 Memory Map and Register Definition
4.3
Register Addresses and Bit Assignments
The registers in the MC9S08QD4 series are divided into these groups:
• Direct-page registers are located in the first 96 locations in the memory map; these 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 RAM.
• The nonvolatile register area consists of a block of 16 locations in flash memory at
0xFFB0–0xFFBF. Nonvolatile register locations include:
— NVPROT and NVOPT are loaded into working registers at reset
— An 8-byte backdoor comparison key that optionally allows a user to gain controlled access to
secure memory
Because the nonvolatile register locations are flash memory, they must be erased and programmed
like other flash memory locations.
Direct-page registers can be accessed with efficient direct addressing mode instructions. Bit manipulation
instructions can be used to access any bit in any direct-page register. Table 4-2 is a summary of all
user-accessible direct-page registers and control bits.
The direct page registers in Table 4-2 can use the more efficient direct addressing mode that 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.
Table 4-2. Direct-Page Register Summary
Address
Register Name
Bit 7
6
5
4
3
2
1
Bit 0
0x0000
PTAD
0
0
PTAD5
PTAD4
PTAD3
PTAD2
PTAD1
PTAD0
0x0001
PTADD
0
0
PTADD5
PTADD4
PTADD3
PTADD2
PTADD1
PTADD0
0x0002–
0x000B
Reserved
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
0x000C
KBISC
0
0
0
0
KBF
KBACK
KBIE
KBIMOD
0x000D
KBIPE
KBIPE7
KBIPE6
KBIPE5
KBIPE4
KBIPE3
KBIPE2
KBIPE1
KBIPE0
0x000E
KBIES
KBEDG7
KBEDG6
KBEDG5
KBEDG4
KBEDG3
KBEDG2
KBEDG1
KBEDG0
0x000F
IRQSC
0
IRQPDD
IRQEDG
IRQPE
IRQF
IRQACK
IRQIE
IRQMOD
0x0010
ADCSC1
COCO
AIEN
ADCO
0x0011
ADCSC2
ADACT
ADTRG
ACFE
ACFGT
—
—
—
—
0x0012
ADCRH
0
0
0
0
0
0
ADR9
ADR8
0x0013
ADCRL
ADR7
ADR6
ADR5
ADR4
ADR3
ADR2
ADR1
ADR0
0x0014
ADCCVH
0
0
0
0
0
0
ADCV9
ADCV8
0x0015
ADCCVL
ADCV7
ADCV6
ADCV4
ADCV3
ADCV2
ADCV1
ADCV0
0x0016
ADCCFG
ADLPC
ADCV5
ADIV
ADCH
ADLSMP
MODE
ADICLK
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
35
Chapter 4 Memory Map and Register Definition
Table 4-2. Direct-Page Register Summary (continued)
Address
Register Name
Bit 7
6
5
4
3
2
1
Bit 0
0x0017
APCTL1
—
—
—
—
ADPC3
ADPC2
ADPC1
ADPC0
0x0018
Reserved
—
—
—
—
—
—
—
—
0x0019
Reserved
—
—
—
—
—
—
—
—
0x001A–
0x001F
Reserved
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
0x0020
TPM2SC
TOF
TOIE
CPWMS
CLKSB
CLKSA
PS2
PS1
PS0
0x0021
TPM2CNTH
Bit 15
14
13
12
11
10
9
Bit 8
0x0022
TPM2CNTL
Bit 7
6
5
4
3
2
1
Bit 0
0x0023
TPM2MODH
Bit 15
14
13
12
11
10
9
Bit 8
0x0024
TPM2MODL
Bit 7
6
5
4
3
2
1
Bit 0
0x0025
TPM2C0SC
CH0F
CH0IE
MS0B
MS0A
ELS0B
ELS0A
0
0
0x0026
TPM2C0VH
Bit 15
14
13
12
11
10
9
Bit 8
0x0027
TPM2C0VL
Bit 7
6
5
4
3
2
1
Bit 0
0x0028–
0x0037
Reserved
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
0x0038
ICSC1
0
CLKS
0
0
0
1
1
IREFSTEN
0
0
LP
0
0
0
0x0039
ICSC2
0x003A
ICSTRM
BDIV
0x003B
ICSSC
0
0
0
0
0
CLKST
0
FTRIM
0x003C
Reserved
—
—
—
—
—
—
—
—
0x0040
TPMSC
TOF
TOIE
CPWMS
CLKSB
CLKSA
PS2
PS1
PS0
0x0041
TPMCNTH
Bit 15
14
13
12
11
10
9
Bit 8
0x0042
TPMCNTL
Bit 7
6
5
4
3
2
1
Bit 0
0x0043
TPMMODH
Bit 15
14
13
12
11
10
9
Bit 8
TRIM
0x0044
TPMMODL
Bit 7
6
5
4
3
2
1
Bit 0
0x0045
TPMC0SC
CH0F
CH0IE
MS0B
MS0A
ELS0B
ELS0A
0
0
0x0046
TPMC0VH
Bit 15
14
13
12
11
10
9
Bit 8
0x0047
TPMC0VL
Bit 7
6
5
4
3
2
1
Bit 0
0x0048
TPMC1SC
CH1F
CH1IE
MS1B
MS1A
ELS1B
ELS1A
0
0
0x0049
TPMC1VH
Bit 15
14
13
12
11
10
9
Bit 8
0x004A
TPMC1VL
Bit 7
6
5
4
3
2
1
Bit 0
0x004B–
0x005F
Reserved
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
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.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
36
Freescale Semiconductor
Chapter 4 Memory Map and Register Definition
Table 4-3. High-Page Register Summary
Address
0x1800
Register Name
SRS
Bit 7
6
5
4
3
2
1
Bit 0
POR
PIN
COP
ILOP
ILAD
0
LVD
0
0x1801
SBDFR
0
0
0
0
0
0
0
BDFR
0x1802
SOPT1
COPE
COPT
STOPE
0
0
0
BKGDPE
RSTPE
0x1803
SOPT2
COPCLKS
0
0
0
0
0
0
0
0x1804
Reserved
—
—
—
—
—
—
—
—
0x1805
Reserved
—
—
—
—
—
—
—
—
0x1806
SDIDH
REV3
REV2
REV1
REV0
ID11
ID10
ID9
ID8
0x1807
SDIDL
ID7
ID6
ID5
ID4
ID3
ID2
ID1
ID0
0x1808
SRTISC
RTIF
RTIACK
RTICLKS
RTIE
0
0x1809
SPMSC1
LVDF
LVDACK
LVDIE
LVDRE
LVDSE
LVDE
01
BGBE
0x180A
SPMSC2
LVWF
LVWACK
LVDV
LVWV
PPDF
PPDACK
—
PPDC
0x180B–
0x181F
Reserved
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
0x1820
FCDIV
DIVLD
PRDIV8
0x1821
FOPT
KEYEN
FNORED
0
0
0
0
SEC01
SEC00
0x1822
Reserved
—
—
—
—
—
—
—
—
0x1823
FCNFG
0
0
KEYACC
0
0
0
0
0
0x1824
FPROT
RTIS
DIV
FPS
0x1825
FSTAT
0x1826
FCMD
0x1827–
0x183F
Reserved
—
—
—
—
—
—
0x1840
PTAPE
0
0
PTAPE5
0x1841
PTASE
0
0
PTASE5
PTASE4
PTASE3
PTASE2
PTASE1
PTASE0
0x1842
PTADS
0
0
PTADS5
PTADS4
PTADS3
PTADS2
PTADS1
PTADS0
0x1843–
0x1847
Reserved
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
1
FCBEF
FCCF
FPVIOL
FPDIS
FACCERR
0
FBLANK
0
0
—
—
—
—
—
—
—
—
—
—
PTAPE4
PTAPE3
PTAPE2
PTAPE1
PTAPE0
FCMD
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 that 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.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
37
Chapter 4 Memory Map and Register Definition
Table 4-4. Nonvolatile Register Summary
Address
Register Name
Bit 7
6
5
4
3
2
1
Bit 0
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
Reserved for
ADCRL of AD26
value during ICS
trim
ADR7
ADR6
ADR5
ADR4
ADR3
ADR2
ADR1
ADR0
Reserved for
ADCRH of AD26
value during ICS
trim and ICS Trim
value “FTRIM”
ADR9
ADR8
—
—
—
—
—
FTRIM
—
—
—
—
—
—
0xFFAA – Reserved
0xFFAC
0xFFAD
0xFFAE
0xFFAF
Reserved for
ICS Trim value
“TRIM”
TRIM
0xFFB0 – NVBACKKEY
0xFFB7
0xFFB8 – Reserved
0xFFBC
8-Byte Comparison Key
—
—
—
—
—
—
—
—
—
—
0xFFBD
NVPROT
FPS
FPDIS
0xFFBE
Unused
—
—
—
—
—
—
—
—
0xFFBF
NVOPT
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).
The ICS factory-trimmed value will be stored in 0xFFAE (bit-0) and 0xFFAF. Development tools, such as
programmers can trim the ICS and the internal temperature sensor (via the ADC) and store the values in
0xFFAD–0xFFAF.
4.4
RAM
The MC9S08QD4 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 or after
wakeup from stop1, 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 (VRAM).
MC9S08QD4 Series MCU Data Sheet, Rev. 3
38
Freescale Semiconductor
Chapter 4 Memory Map and Register Definition
For compatibility with M68HC05 MCUs, the HCS08 resets the stack pointer to 0x00FF. In the
MC9S08QD4 series, it is usually best to reinitialize 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 Semiconductor-provided equate file).
LDHX
TXS
#RamLast+1
;point one past RAM
;SP<-(H:X-1)
When security is enabled, the RAM is considered a secure memory resource and is not accessible through
BDM or through code executing from non-secure memory. See Section 4.6, “Security,” for a detailed
description of the security feature.
4.5
Flash
The flash memory is intended primarily for program storage. In-circuit programming allows the operating
program to be loaded into the flash memory after final assembly of the application product. It is possible
to program the entire array through the single-wire background debug interface. Because no special
voltages are needed for flash erase and programming operations, in-application programming is also
possible through other software-controlled communication paths. For a more detailed discussion of
in-circuit and in-application programming, refer to the HCS08 Family Reference Manual, Volume I,
Freescale Semiconductor document order number HCS08RMv1.
4.5.1
Features
Features of the flash memory include:
• Flash size
— MC9S08QD4/S9S08QD4: 4096 bytes (8 pages of 512 bytes each)
— MC9S08QD2/S9S08QD2: 2048 bytes (4 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 performed 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
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
39
Chapter 4 Memory Map and Register Definition
program and erase pulses. An integer number of these timing pulses is 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
1
4.5.3
Parameter
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 can 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 can be erased.
NOTE
• A mass or page erase of the last page in flash will erase the factory
programmed internal reference clock trim value.
• Do not program any byte in the flash more than once after a successful
erase operation. Reprogramming bits in 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.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
40
Freescale Semiconductor
Chapter 4 Memory Map and Register Definition
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 following any reset before using any flash
commands.
START
FACCERR ?
0
CLEAR ERROR
(1) Required only once
WRITE TO FCDIV(1)
after reset.
WRITE TO FLASH
TO BUFFER ADDRESS AND DATA
WRITE COMMAND TO FCMD
WRITE 1 TO FCBEF
TO LAUNCH COMMAND
AND CLEAR FCBEF (2)
FPVIO OR
FACCERR ?
(2)
Wait at least four bus cycles before
checking FCBEF or FCCF.
YES
ERROR EXIT
NO
0
FCCF ?
1
DONE
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
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
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
41
Chapter 4 Memory Map and Register Definition
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 0s.
The first byte of a series of sequential bytes being programmed in burst mode will take the same amount
of time to program as a byte programmed in standard mode. Subsequent bytes will program in the burst
program time provided that the conditions above are met. In the case the next sequential address is the
beginning of a new row, the program time for that byte will be the standard time instead of the burst time.
This is because the high voltage to the array must be disabled and then enabled again. If a new burst
command has not been queued before the current command completes, then the charge pump will be
disabled and high voltage removed from the array.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
42
Freescale Semiconductor
Chapter 4 Memory Map and Register Definition
START
0
FACCERR ?
1
CLEAR ERROR
WRITE TO FCDIV(1)
FCBEF ?
(1)
Required only once
after reset.
0
1
WRITE TO FLASH
TO BUFFER ADDRESS AND DATA
WRITE COMMAND TO FCMD
WRITE 1 TO FCBEF
TO LAUNCH COMMAND
AND CLEAR FCBEF (2)
FPVIO OR
FACCERR ?
(2)
Wait at least four bus cycles before
checking FCBEF or FCCF.
YES
ERROR EXIT
NO
YES
NEW BURST COMMAND ?
NO
0
FCCF ?
1
DONE
Figure 4-3. Flash Burst Program Flowchart
4.5.5
Access Errors
An access error occurs whenever the command execution protocol is violated.
Any of the following specific actions will cause the access error flag (FACCERR) in FSTAT to be set.
FACCERR must be cleared by writing a 1 to FACCERR in FSTAT before any command can be
processed.
• Writing to a flash address before the internal flash clock frequency has been set by writing to the
FCDIV register
• Writing to a flash address while FCBEF is not set (A new command cannot be started until the
command buffer is empty.)
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
43
Chapter 4 Memory Map and Register Definition
•
•
•
•
•
•
•
•
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
Writing any flash control register other than to 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
do blank check and mass erase commands only 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. Because 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 in Figure 4-4. The FPS bits are used as the upper bits of the
last address of unprotected memory. This address is formed by concatenating FPS7:FPS1 with logic 1 bits
as shown. For example, in order to protect the last 8192 bytes of memory (addresses 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
A15
A14
A13
FPS4
FPS3
FPS2
FPS1
A12
A11
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
MC9S08QD4 Series MCU Data Sheet, Rev. 3
44
Freescale Semiconductor
Chapter 4 Memory Map and Register Definition
One use for block protection is to block protect an area of flash memory for a bootloader program. This
bootloader program then can be used to erase the rest of the flash memory and reprogram it. Because the
bootloader is protected, it remains intact even if MCU power is lost in the middle of an erase and
reprogram operation.
4.5.7
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 0. 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. For
example, vector redirection is enabled and an interrupt occurs, 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 MC9S08QD4 series includes circuitry to prevent unauthorized access to the contents of flash and
RAM memory. When security is engaged, flash and RAM are considered secure resources. Direct-page
registers, high-page registers, and the background debug controller are considered unsecured resources.
Programs executing within secure memory have normal access to any MCU memory locations and
resources. Attempts to access a secure memory location with a program executing from an unsecured
memory space or through the background debug interface are blocked (writes are ignored and reads return
all 0s).
Security is engaged or disengaged based on the state of two 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 performed 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, it is good practice to immediately
program the SEC00 bit to 0 in NVOPT so SEC01:SEC00 = 1:0. This would allow the MCU to remain
unsecured after a subsequent reset.
The on-chip debug module cannot be enabled while the MCU is secure. The separate background debug
controller can 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
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
45
Chapter 4 Memory Map and Register Definition
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 performed 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
performed 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 written matches the key
stored in the flash locations, SEC01:SEC00 are automatically changed to 1:0 and security will be
disengaged until the next reset.
The security key can be written only from secure memory (either RAM or flash), so it cannot be entered
through background commands without the cooperation of a secure user program.
The backdoor comparison key (NVBACKKEY through NVBACKKEY+7) is located in flash memory
locations in the nonvolatile register space so users can program these locations exactly as they would
program any other flash memory location. The nonvolatile registers are in the same 512-byte block of flash
as the reset and interrupt vectors, so block protecting that space also block protects the backdoor
comparison key. Block protects cannot be changed from user application programs, so if the vector space
is block protected, the backdoor security key mechanism cannot permanently change the block protect,
security settings, or the backdoor key.
Security can always be disengaged through the background debug interface by taking these steps:
1. Disable any block protections by writing FPROT. FPROT can be written only with background
debug commands, not from application software.
2. Mass erase flash if necessary.
3. Blank check flash. Provided flash is completely erased, security is disengaged until the next reset.
To avoid returning to secure mode after the next reset, program NVOPT so SEC01:SEC00 = 1:0.
4.7
Flash Registers and Control Bits
The flash module has nine 8-bit registers in the high-page register space, two locations (NVOPT,
NVPROT) in the nonvolatile register space in flash memory are copied into corresponding high-page
control registers (FOPT, FPROT) 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 Semiconductor-provided equate or header
file normally is used to translate these names into the appropriate absolute addresses.
4.7.1
Flash Clock Divider Register (FCDIV)
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.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
46
Freescale Semiconductor
Chapter 4 Memory Map and Register Definition
7
R
6
5
4
3
2
1
0
0
0
0
DIVLD
PRDIV8
DIV
W
Reset
0
0
0
0
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
5:0
DIV
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.
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 DIV 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 and Equation 4-2.
if PRDIV8 = 0 – fFCLK = fBus ÷ (DIV + 1)
Eqn. 4-1
if PRDIV8 = 1 – fFCLK = fBus ÷ (8 × (DIV + 1))
Eqn. 4-2
Table 4-7 shows the appropriate values for PRDIV8 and DIV for selected bus frequencies.
Table 4-7. Flash Clock Divider Settings
fBus
PRDIV8
(Binary)
DIV
(Decimal)
fFCLK
Program/Erase Timing Pulse
(5 μs Min, 6.7 μs Max)
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
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
47
Chapter 4 Memory Map and Register Definition
4.7.2
Flash Options Register (FOPT and NVOPT)
During reset, the contents of the nonvolatile location NVOPT are copied from flash into FOPT. 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. SEC01:SEC00 changes to 1:0 after successful
backdoor key entry or a successful blank check of flash.
For more detailed information about security, refer to Section 4.6, “Security.”
Table 4-9. Security States1
1
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.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
48
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Chapter 4 Memory Map and Register Definition
4.7.3
R
Flash Configuration Register (FCNFG)
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 is copied from flash into FPROT. This
register can be read at any time, but user program writes have no meaning or effect.
7
R
6
5
4
3
2
1
FPS(1)
0
FPDIS(1)
W
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)
Table 4-11. FPROT Register Field Descriptions
Field
Description
7:1
FPS
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
Flash Protection Disable
0 Flash block specified by FPS7:FPS1 is block protected (program and erase not allowed).
1 No flash block is protected.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
49
Chapter 4 Memory Map and Register Definition
4.7.5
Flash Status Register (FSTAT)
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 can be written to the command buffer.
6
FCCF
Flash Command Complete Flag — FCCF is set automatically when the command buffer is empty and no
command is being processed. FCCF is cleared automatically when a new command is started (by writing 1 to
FCBEF to register a command). Writing to FCCF has no meaning or effect.
0 Command in progress
1 All commands complete
5
FPVIOL
Protection Violation Flag — FPVIOL is set automatically when FCBEF is cleared to register a command that
attempts to erase or program a location in a protected block (the erroneous command is ignored). FPVIOL is
cleared by writing a 1 to FPVIOL.
0 No protection violation.
1 An attempt was made to erase or program a protected location.
4
FACCERR
Access Error Flag — FACCERR is set automatically when the proper command sequence is not obeyed exactly
(the erroneous command is ignored), if a program or erase operation is attempted before the FCDIV register has
been initialized, or if the MCU enters stop while a command was in progress. For a more detailed discussion of
the exact actions that are considered access errors, see Section 4.5.5, “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).
MC9S08QD4 Series MCU Data Sheet, Rev. 3
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Chapter 4 Memory Map and Register Definition
4.7.6
Flash Command Register (FCMD)
Only five command codes are recognized in normal user modes as shown in Table 4-13. Refer to
Section 4.5.3, “Program and Erase Command Execution,” for a detailed discussion of flash programming
and erase operations.
R
7
6
5
4
3
2
1
0
0
0
0
0
0
0
0
0
0
0
0
0
W
Reset
FCMD
0
0
0
0
= Unimplemented or Reserved
Figure 4-10. Flash Command Register (FCMD)
Table 4-13. 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.
It is not necessary to perform a blank check command after a mass erase operation. Only blank check is
required as part of the security unlocking mechanism.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
51
Chapter 4 Memory Map and Register Definition
MC9S08QD4 Series MCU Data Sheet, Rev. 3
52
Freescale Semiconductor
Chapter 5
Resets, Interrupts, and General System Control
5.1
Introduction
This chapter discusses basic reset and interrupt mechanisms and the various sources of reset and interrupts
in the MC9S08QD4 series. Some interrupt sources from peripheral modules are discussed in greater detail
within other sections of this data sheet. This section gathers basic information about all reset and interrupt
sources in one place for easy reference. A few reset and interrupt sources, including the computer
operating properly (COP) watchdog and real-time interrupt (RTI), are not part of on-chip peripheral
systems with their own chapters 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 5-2)
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 MC9S08QD4 series has the following sources for reset:
• External pin reset (PIN) - enabled using RSTPE in SOPT1
• 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
Each of these sources, with the exception of the background debug forced reset, has an associated bit in
the system reset status register.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
53
Chapter 5 Resets, Interrupts, and General System Control
5.4
Computer Operating Properly (COP) Watchdog
The COP watchdog is intended to force a system reset when the application software fails to execute as
expected. To prevent a system reset from the COP timer (when it is enabled), application software must
reset the COP 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 COPE becomes set in SOPT1 enabling the COP watchdog (see Section 5.8.5, “System
Options Register 2 (SOPT2),” for additional information). If the COP watchdog is not used in an
application, it can be disabled by clearing COPE. The COP counter is reset by writing any value to the
address of SRS. This write does not affect the data in the read-only SRS. Instead, the act of writing to this
address is decoded and sends a reset signal to the COP counter.
The COPCLKS bit in SOPT2 (see Section 5.8.5, “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 32 kHz clock source. With each clock source, there is an associated short and long
time-out controlled by COPT in SOPT1. Table 5-1 summaries the control functions of the COPCLKS and
COPT bits. The COP watchdog defaults to operation from the 32 kHz clock source and the associated long
time-out (28 cycles).
Table 5-1. COP Configuration Options
Control Bits
1
Clock Source
COP Overflow Count
0
~32 kHz
210 cycles (32 ms)1
0
1
~32 kHz
213 cycles (256 ms)1
1
0
Bus
213 cycles
1
1
Bus
218 cycles
COPCLKS
COPT
0
Values are shown in this column based on tRTI = 1 ms. See tRTI in the Section A.8.1,
“Control Timing,” for the tolerance of this value.
Even if the application will use the reset default settings of COPE, COPCLKS and COPT, the user must
write to the write-once SOPT1 and SOPT2 registers during reset initialization to lock in the settings. That
way, they cannot be changed accidentally if the application program gets lost. The initial writes to SOPT1
and SOPT2 will reset the COP counter.
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.
In Background debug mode, the COP counter will not increment.
When the bus clock source is selected, the COP counter does not increment while the system is in stop
mode. The COP counter resumes once the MCU exits stop mode.
When the 32 kHz clock source is selected, the COP counter is re-initialized to zero upon entry to stop
mode. The COP counter begins from zero once the MCU exits stop mode.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
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Chapter 5 Resets, Interrupts, and General System Control
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 was 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 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
can 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 M68HC08 devices, the H register is not
automatically saved and restored. It is good programming practice to push
H onto the stack at the start of the interrupt service routine (ISR) and restore
it immediately before the RTI that is used to return from the ISR.
When two or more interrupts are pending when the I bit is cleared, the highest priority source is serviced
first (see Table 5-2).
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
55
Chapter 5 Resets, Interrupts, and General System Control
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.
UNSTACKING
ORDER
TOWARD LOWER ADDRESSES
7
0
5
1
4
2
3
3
2
4
PROGRAM COUNTER HIGH
1
5
PROGRAM COUNTER LOW
CONDITION CODE REGISTER
SP AFTER
INTERRUPT STACKING
ACCUMULATOR
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 is cleared at the beginning of the ISR so that if another interrupt is generated by this
same source, it will be registered so it can be serviced after completion of the current ISR.
5.5.2
External Interrupt Request (IRQ) Pin
External interrupts are managed by the IRQ status and control register, IRQSC. 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 in order for the IRQ pin to act as the interrupt
request (IRQ) input. As an IRQ input, the user can choose the polarity of edges or levels detected
(IRQEDG), whether the pin detects edges-only or edges and levels (IRQMOD), and whether an event
causes an interrupt or only sets the IRQF flag which can be polled by software.
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Chapter 5 Resets, Interrupts, and General System Control
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 to detect. 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 reconfigures the detection logic so it detects edge events and pin levels. In this
edge detection mode, the IRQF status flag becomes set when an edge is detected (when the IRQ pin
changes from the deasserted to the asserted level), but the flag is continuously set (and cannot be cleared)
as long as the IRQ pin remains at the asserted level.
5.5.3
Interrupt Vectors, Sources, and Local Masks
Table 5-2 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.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
57
Chapter 5 Resets, Interrupts, and General System Control
Table 5-2. Vector Summary
Vector
Priority
Vector
Number
Address
(High:Low)
Lower
31
through
24
0xFFC0:FFC1
through
0xFFCE:FFCF
23
0xFFD0:FFD1
Vrti
22
21
20
19
18
17
16
15
14
13
12
11
10
9
8
7
6
5
4
3
0xFFD2:FFD3
0xFFD4:FFD5
0xFFD6:FFD7
0xFFD8:FFD9
0xFFDA:FFDB
0xFFDC:FFDD
0xFFDE:FFDF
0xFFE0:FFE1
0xFFE2:FFE3
0xFFE4:FFE5
0xFFE6:FFE7
0xFFE8:FFE9
0xFFEA:FFEB
0xFFEC:FFED
0xFFEE:FFEF
0xFFF0:FFF1
0xFFF2:FFF3
0xFFF4:FFF5
0xFFF6:FFF7
0xFFF8:FFF9
—
—
—
Vadc1
Vkeyboard1
—
—
—
—
—
—
—
Vtpm2ovf
—
Vtpm2ch0
Vtpm1ovf
Vtpm1ch1
Vtpm1ch0
—
Virq
2
0xFFFA:FFFB
Vlvd
1
0xFFFC:FFFD
Vswi
0
Vector Name
0xFFFE:FFFF
Module
Enable
Description
Unused Vector Space
(available for user program)
Vreset
System
control
—
—
—
ADC1
KBI1
—
—
—
—
—
—
—
TPM2
—
TPM2
TPM1
TPM1
TPM1
—
IRQ
System
control
CPU
System
control
Higher
5.6
Source
RTIF
RTIE
Real-time interrupt
—
—
—
COCO
KBF
—
—
—
—
—
—
—
TOF
—
CH0F
TOF
CH1F
CH0F
—
IRRQF
—
—
—
AIEN
KBIE
—
—
—
—
—
—
—
TOIE
—
CH0IE
TOIE
CH1IE
CH0IE
—
IRQIE
—
—
—
ADC1
Keyboard pins
—
—
—
—
—
—
—
TPM2 overflow
—
TPM2 channel 0
TPM1 overflow
TPM1 channel 1
TPM1 channel 0
—
IRQ pin
LVDF
LVDIE
Low voltage detect
—
Software interrupt
COPE
LVDRE
RSTPE
—
—
—
Watchdog timer
Low-voltage detect
External pin
Illegal opcode
Illegal address
power-on-reset
SWI
Instruction
COP
LVD
RESET pin
Illegal opcode
Illegal address
POR
Low-Voltage Detect (LVD) System
The MC9S08QD4 series includes a system to protect against low voltage conditions in order to protect
memory contents and control MCU system states during supply voltage variations. The system is
comprised of a power-on reset (POR) circuit and an LVD circuit with a user selectable trip voltage, either
high (VLVDH) or low (VLVDL). The LVD circuit is enabled when LVDE in SPMSC1 is high and the trip
voltage is selected by LVDV in SPMSC3. The LVD is disabled upon entering any of the stop modes unless
LVDSE is set in SPMSC1. If LVDSE and LVDE are both set, then the MCU cannot enter stop1 or stop2,
and the current consumption in stop3 with the LVD enabled will be greater.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
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Chapter 5 Resets, Interrupts, and General System Control
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 MCU
in reset until the supply has risen above the VLVDL level. Both the POR bit and the LVD bit in SRS are set
following a POR.
5.6.2
LVD Reset Operation
The LVD can be configured to generate a reset upon detection of a low voltage condition by setting
LVDRE to 1. After an LVD reset has occurred, the LVD system will hold the MCU in reset until the supply
voltage has risen above the level determined by LVDV. The LVD bit in the SRS register is set following
either an LVD reset or POR.
5.6.3
LVD Interrupt Operation
When a low voltage condition is detected and the LVD circuit is configured using SPMSC1 for interrupt
operation (LVDE set, LVDIE set, and LVDRE clear), then LVDF in SPMSC1 will be set and an LVD
interrupt request will occur.
5.6.4
Low-Voltage Warning (LVW)
The LVD system has a low voltage warning flag to indicate to the user that the supply voltage is
approaching, but is 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 SPMSC3.
5.7
Real-Time Interrupt (RTI)
The real-time interrupt function can be used to generate periodic interrupts. The RTI can accept two
sources of clocks, the 1 kHz internal clock or an 32 kHz ICS clock if available. The RTICLKS bit in
SRTISC is used to select the RTI clock source.
Both clock source can be used when the MCU is in run, wait or stop3 mode. When using the 32 kHz ICS
clock in stop3, it must be enabled in stop (EREFSTEN = 1) and configured for low frequency operation
(RANGE = 0). Only the internal 1 kHz clock source can be selected to wake the MCU from stop1 or stop2
modes.
The SRTISC register includes a read-only status flag, a write-only acknowledge bit, and a 3-bit control
value (RTIS) used to select one of seven wakeup periods. The RTI has a local interrupt enable, RTIE, to
allow masking of the real-time interrupt. The RTI can be disabled by writing each bit of RTIS to zeroes,
and no interrupts will be generated. See Section 5.8.7, “System Real-Time Interrupt Status and Control
Register (SRTISC),” for detailed information about this register.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
59
Chapter 5 Resets, Interrupts, and General System Control
5.8
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 3, “Modes of Operation,” 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, SOPT2 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.”
5.8.1
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)
Table 5-3. 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/pulldown 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. When IRQEDG = 1 and the internal pull device is enabled, the pullup device is
reconfigured as an optional pulldown device.
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
IRQ Flag — This read-only status bit indicates when an interrupt request event has occurred.
0 No IRQ request.
1 IRQ event detected.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
60
Freescale Semiconductor
Chapter 5 Resets, Interrupts, and General System Control
Table 5-3. IRQSC Register Field Descriptions (continued)
Field
Description
2
IRQACK
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.
1
IRQIE
0
IRQMOD
5.8.2
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. The IRQEDG control bit determines the polarity of edges and levels that are detected as interrupt
request events. See Section 5.5.2.2, “Edge and Level Sensitivity,” for more details.
0 IRQ event on falling edges or rising edges only.
1 IRQ event on falling edges and low levels or on rising edges and high levels.
System Reset Status Register (SRS)
This high-page register includes 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, all of the status bits in SRS will be
cleared. Writing any value to this register address clears the COP watchdog timer without affecting the
contents of this register. The reset state of these bits depends on what caused the MCU to reset.
R
7
6
5
4
3
2
1
0
POR
PIN
COP
ILOP
ILAD
0
LVD
0
W
1
Writing any value to SRS address clears COP watchdog timer.
POR:
1
0
0
0
0
0
1
0
LVR:
0
0
0
0
0
0
1
0
Any
other
reset:
0
(1)
(1)
(1)
(1)
0
0
0
Any of these reset sources that are active at the time of reset entry will cause the corresponding bit(s) to be set; bits
corresponding to sources that are not active at the time of reset entry will be cleared.
Figure 5-3. System Reset Status (SRS)
Table 5-4. 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.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
61
Chapter 5 Resets, Interrupts, and General System Control
Table 5-4. SRS Register Field Descriptions (continued)
Field
Description
5
COP
Computer Operating Properly (COP) Watchdog — Reset was caused by the COP watchdog timer timing out.
This reset source can 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.
3
ILAD
Illegal Address — Reset was caused by an attempt to access either data or an instruction at an unimplemented
memory address.
0 Reset not caused by an illegal address
1 Reset caused by an illegal address
1
LVD
Low Voltage Detect — If the LVDRE bit is 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.
5.8.3
System Background Debug Force Reset Register (SBDFR)
This high-page 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.
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 5-5. SBDFR Register Field Descriptions
Field
Description
0
BDFR
Background Debug Force Reset — A serial background command such as WRITE_BYTE can be used to allow
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. To enter user mode, PTA4/TPM2CH0O/BKGD/MS must be high immediately
after issuing WRITE_BYTE command. To enter BDM, PTA4/TPM2CH0O/BKGD/MS must be low immediately
after issuing WRITE_BYTE command. See A.8.1, “Control Timing,” for more information.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
62
Freescale Semiconductor
Chapter 5 Resets, Interrupts, and General System Control
5.8.4
System Options Register 1 (SOPT1)
This high-page register is a write-once register so only the first write after reset is honored. It can be read
at any time. Any subsequent attempt to write to SOPT1 (intentionally or unintentionally) is ignored to
avoid accidental changes to these sensitive settings. SOPT1 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.
1
4
7
6
5
COPE
COPT
STOPE
Reset:
1
1
0
1
0
POR:
1
1
0
1
0
R
3
2
1
0
0
0
BKGDPE
RSTPE
0
1
U
0
1
0
W
= Unimplemented or Reserved
1
U = unaffected
Bit 4 is reserved, writes will change the value but will have no effect on this MCU.
Figure 5-5. System Options Register 1 (SOPT1)
Table 5-6. SOPT1 Register Field Descriptions
Field
Description
7
COPE
COP Watchdog Enable — This write-once bit selects whether the COP watchdog is enabled.
0 COP watchdog timer disabled.
1 COP watchdog timer enabled (force reset on timeout).
6
COPT
COP Watchdog Timeout — This write-once bit selects the timeout period of the COP. COPT along with
COPCLKS in SOPT2 defines the COP timeout period.
0 Short timeout period selected.
1 Long timeout period selected.
5
STOPE
Stop Mode Enable — This write-once bit is used to enable 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.
1
BKGDPE
Background Debug Mode Pin Enable — This write-once bit when set enables the
PTA4/TPM2CH0O/BKGD/MS pin to function as BKGD/MS. When clear, the pin functions as one of its output only
alternative functions. This pin defaults to the BKGD/MS function following any MCU reset.
0 PTA4/TPM2CH0O/BKGD/MS pin functions as PTA4 or TPM2CH0O.
1 PTA4/TPM2CH0O/BKGD/MS pin functions as BKGD/MS.
0
RSTPE
RESET Pin Enable — This write-once bit when set enables the PTA5/TPM2CH0I/IRQ/RESET pin to function as
RESET. When clear, the pin functions as one of its input only alternative functions. This pin defaults to its
input-only port function following an MCU POR. When RSTPE is set, an internal pullup device is enabled on
RESET.
0 PTA5/TPM2CH0I/IRQ/RESET pin functions as PTA5, IRQ or TPM2CH0I.
1 PTA5/TPM2CH0I/IRQ/RESET pin functions as RESET.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
63
Chapter 5 Resets, Interrupts, and General System Control
5.8.5
System Options Register 2 (SOPT2)
This high-page register contains bits to configure MCU-specific features on MC9S08QD4 series devices.
7
R
COPCLKS1
6
5
4
3
2
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
W
Reset:
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
5.8.6
Description
COP Watchdog Clock Select — This write-once bit selects the clock source of the COP watchdog.
0 Internal 32 kHz clock is source to COP.
1 Bus clock is source to COP.
System Device Identification Register (SDIDH, SDIDL)
These high-page read-only registers are 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.
R
7
6
5
4
3
2
1
0
REV3
REV2
REV1
REV0
ID11
ID10
ID9
ID8
01
01
01
01
0
0
0
0
W
Reset:
= Unimplemented or Reserved
1
The revision number that is hard coded into these bits reflects the current silicon revision level.
Figure 5-7. System Device Identification Register — High (SDIDH)
Table 5-8. SDIDH Register Field Descriptions
Field
Description
7:4
REV[3:0]
Revision Number — The high-order 4 bits of address SDIDH are hard coded to reflect the current mask set
revision number (0–F).
3:0
ID[11:8]
Part Identification Number — Each derivative in the HCS08 family has a unique identification number. The
MC9S08QD4 series is hard coded to the value 0x011. See also ID bits in Table 5-9.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
64
Freescale Semiconductor
Chapter 5 Resets, Interrupts, and General System Control
R
7
6
5
4
3
2
1
0
ID7
ID6
ID5
ID4
ID3
ID2
ID1
ID0
0
0
0
0
1
0
0
1
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]
5.8.7
Description
Part Identification Number — Each derivative in the HCS08 family has a unique identification number. The
MC9S08QD4 series is hard coded to the value 0x011. See also ID bits in Table 5-8.
System Real-Time Interrupt Status and Control Register (SRTISC)
This high-page register contains status and control bits for the RTI.
R
7
6
RTIF
0
W
Reset:
5
4
RTICLKS
RTIE
0
0
3
2
1
0
0
RTIS
RTIACK
0
0
0
0
0
0
= Unimplemented or Reserved
Figure 5-9. System RTI Status and Control Register (SRTISC)
Table 5-10. SRTISC Register Field Descriptions
Field
7
RTIF
Description
Real-Time Interrupt Flag — This read-only status bit indicates the periodic wakeup timer has timed out.
0 Periodic wakeup timer not timed out.
1 Periodic wakeup timer timed out.
6
RTIACK
Real-Time Interrupt Acknowledge — This write-only bit is used to acknowledge real-time interrupt request
(write 1 to clear RTIF). Writing 0 has no meaning or effect. Reads always return 0.
5
RTICLKS
Real-Time Interrupt Clock Select — This read/write bit selects the clock source for the real-time interrupt.
0 Real-time interrupt request clock source is internal 1 kHz oscillator.
1 Real-time interrupt request clock source is 32 kHz ICS clock.
4
RTIE
Real-Time Interrupt Enable — This read-write bit enables real-time interrupts.
0 Real-time interrupts disabled.
1 Real-time interrupts enabled.
2:0
RTIS
Real-Time Interrupt Delay Selects — These read/write bits select the period for the RTI. See Table 5-11
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
65
Chapter 5 Resets, Interrupts, and General System Control
Table 5-11. Real-Time Interrupt Period
RTIS2:RTIS1:RTIS0
Using Internal 1 kHz Clock Source1 2
Using 32 kHz ICS Clock Source
Period = text3
0:0:0
Disable RTI
Disable RTI
0:0:1
8 ms
text × 256
0:1:0
32 ms
text × 1024
0:1:1
64 ms
text × 2048
1:0:0
128 ms
text × 4096
1:0:1
256 ms
text × 8192
1:1:0
512 ms
text × 16384
1:1:1
1.024 s
text × 32768
1
Values are shown in this column based on tRTI = 1 ms. See tRTI in the Section A.8.1, “Control Timing,” for the tolerance of this
value.
2 The initial RTI timeout period will be up to one 1 kHz clock period less than the time specified.
3 t
ext is the period of the 32 kHz ICS frequency.
5.8.8
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. To configure the low voltage detect trip
voltage, see Table 5-13 for the LVDV bit description in SPMSC2.
R
7
6
LVDF
0
W
Reset:
5
4
3
2
LVDIE
LVDRE2
LVDSE
LVDE 2
0
1
1
1
1
1
0
0
BGBE
LVDACK
0
0
0
0
= Unimplemented or Reserved
1
Bit 1 is a reserved bit that must always be written to 0.
2
This bit can be written only one time after reset. Additional writes are ignored.
Figure 5-10. System Power Management Status and Control 1 Register (SPMSC1)
Table 5-12. SPMSC1 Register Field Descriptions
Field
Description
7
LVDF
Low-Voltage Detect Flag — Provided LVDE = 1, this read-only status bit indicates a low-voltage detect event.
6
LVDACK
Low-Voltage Detect Acknowledge — This write-only bit is used to acknowledge low voltage detection errors
(write 1 to clear LVDF). Reads always return 0.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
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Chapter 5 Resets, Interrupts, and General System Control
Table 5-12. SPMSC1 Register Field Descriptions (continued)
Field
Description
5
LVDIE
Low-Voltage Detect Interrupt Enable — This bit enables hardware interrupt requests for LVDF.
0 Hardware interrupt disabled (use polling).
1 Request a hardware interrupt when LVDF = 1.
4
LVDRE
Low-Voltage Detect Reset Enable — This write-once bit enables LVDF events to generate a hardware reset
(provided LVDE = 1).
0 LVDF does not generate hardware resets.
1 Force an MCU reset when LVDF = 1.
3
LVDSE
Low-Voltage Detect Stop Enable — Provided LVDE = 1, this read/write bit determines whether the low-voltage
detect function operates when the MCU is in stop mode.
0 Low-voltage detect disabled during stop mode.
1 Low-voltage detect enabled during stop mode.
2
LVDE
Low-Voltage Detect Enable — This 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.
5.8.9
System Power Management Status and Control 2 Register
(SPMSC2)
This high-page register contains status and control bits to configure the stop mode behavior of the MCU.
See Section 3.6, “Stop Modes,” for more information on stop modes.
R
7
6
LVWF
0
5
4
LVDV
LVWV
PPDF
0
1
0
PPDC1
PPDACK
POR:
02
0
0
0
0
0
0
0
LVDR:
0
2
0
U
U
0
0
0
0
Other
Reset
02
0
U
U
0
0
0
0
= Unimplemented or Reserved
2
2
LVWACK
W
1
3
U = Unaffected by reset
This bit can be written only one time after reset. Additional writes are ignored.
LVWF will be set in the case when Vsupply transitions below the trip point or after reset and Vsupply is already below VLVW.
Figure 5-11. System Power Management Status and Control 2 Register (SPMSC2)
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
67
Chapter 5 Resets, Interrupts, and General System Control
Table 5-13. SPMSC2 Register Field Descriptions
Field
7
LVWF
6
LVWACK
Description
Low-Voltage Warning Flag — The LVWF bit indicates the low voltage warning status.
0 Low voltage warning not preset.
1 Low voltage warning is present or was present.
Low-Voltage Warning Acknowledge — The LVWACK bit is the low-voltage warning acknowledge.
Writing a 1 to LVWACK clears LVWF to a 0 if a low voltage warning is not present.
5
LVDV
Low-Voltage Detect Voltage Select — The LVDV bit selects the LVD trip point voltage (VLVD).
0 Low trip point selected (VLVD = VLVDL).
1 High trip point selected (VLVD = VLVDH).
4
LVWV
Low-Voltage Warning Voltage Select — The LVWV bit selects the LVW trip point voltage (VLVW).
0 Low trip point selected (VLVW = VLVWL).
1 High trip point selected (VLVW = VLVWH).
3
PPDF
Partial Power Down Flag — The PPDF bit indicates that the MCU has exited the stop2 mode.
0 Not stop2 mode recovery.
1 Stop2 mode recovery.
2
PPDACK
0
PPDC
Partial Power Down Acknowledge — Writing a 1 to PPDACK clears the PPDF bit.
Partial Power Down Control — The write-once PPDC bit controls whether stop2 or stop3 mode is selected.
0 Stop3 mode enabled.
1 Stop2, partial power down, mode enabled.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
68
Freescale Semiconductor
Chapter 6
Parallel Input/Output Control
This section explains software controls related to parallel input/output (I/O) and pin control. The
MC9S08QD4 series has one parallel I/O port which include a total of 4 I/O pins, one output-only pin, and
one input-only pin. See Section Chapter 2, “External Signal Description,” for more information about pin
assignments and external hardware considerations of these pins.
All of these 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 that when a peripheral is enabled, the I/O functions associated with
the shared pins are disabled. After reset, the shared peripheral functions are disabled so that the pins are
controlled by the I/O. All of the I/Os are configured as inputs (PTxDDn = 0) with pullup devices disabled
(PTxPEn = 0), except for output-only pin PTA4 which defaults to BKGD/MS pin.
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.
6.1
Port Data and Data Direction
Reading and writing of parallel I/Os is performed through the port data registers. The direction, either 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 shown in Figure 6-1.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
69
Chapter 6 Parallel Input/Output Control
PTxDDn
D
Output Enable
Q
PTxDn
D
Output Data
Q
1
Port Read
Data
0
Input Data
Synchronizer
BUSCLK
Figure 6-1. Parallel I/O Block Diagram
The data direction control bit (PTxDDn) determines whether the output buffer for the associated pin is
enabled, and also controls the source for port data register reads. The input buffer for the associated pin is
always enabled unless the pin is enabled as an analog function or is an output-only pin.
When a shared digital function is enabled for a pin, the output buffer is controlled by the shared function.
However, the data direction register bit will continue to control the source for reads of the port data register.
When a shared analog function is enabled for a pin, both the input and output buffers are disabled. A value
of 0 is read for any port data bit where the bit is an input (PTxDDn = 0) and the input buffer is disabled. In
general, whenever a pin is shared with both an alternate digital function and an analog function, the analog
function has priority such that if both the digital and analog functions are enabled, the analog function
controls the pin.
It is a good programming practice to write to the port data register before changing the direction of a port
pin to become an output. This ensures that the pin will not be driven momentarily with an old data value
that happened to be in the port data register.
6.2
Pin Control — Pullup, Slew Rate and Drive Strength
Associated with the parallel I/O ports is a set of registers located in the high-page register space that
operate independently of the parallel I/O registers. These registers are used to control pullups, slew rate
and drive strength for the pins.
6.3
Pin Behavior in Stop Modes
Pin behavior following execution of a STOP instruction depends on the stop mode that is entered. An
explanation of pin behavior for the various stop modes follows:
MC9S08QD4 Series MCU Data Sheet, Rev. 3
70
Freescale Semiconductor
Chapter 6 Parallel Input/Output Control
•
In stop1 mode, all internal registers including parallel I/O control and data registers are powered
off. Each of the pins assumes its default reset state (output buffer and internal pullup disabled).
Upon exit from stop1, all pins must be re-configured the same as if the MCU had been reset.
Stop2 mode is a partial power-down mode, whereby latches maintain the pin 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 previously enabled will 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 of pins
is now permitted again in the user’s application program.
In stop3 mode, all pin states are maintained because internal logic stays powered up. Upon
recovery, all pin functions are the same as before entering stop3.
•
•
6.4
Parallel I/O Registers
6.4.1
Port A Registers
This section provides information about the registers associated with the parallel I/O ports.
Refer to tables in Chapter 4, “Memory Map and Register Definition,” for the absolute address assignments
for all parallel I/O. This section refers to registers and control bits only by their names. A Freescale
Semiconductor-provided equate or header file normally is used to translate these names into the
appropriate absolute addresses.
6.4.1.1
R
Port A Data (PTAD)
7
6
0
0
5
4
3
2
1
0
PTAD51
PTAD42
PTAD3
PTAD2
PTAD1
PTAD0
0
0
0
0
0
0
W
Reset:
0
0
1
Reads of bit PTAD5 always return the pin value of PTA5, regardless of the value stored in bit PTADD5.
2
Reads of bit PTAD4 always return the contents of PTAD4, regardless of the value stored in bit PTADD4.
Figure 6-2. Port A Data Register (PTAD)
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
71
Chapter 6 Parallel Input/Output Control
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.
6.4.1.2
R
Port A Data Direction (PTADD)
7
6
0
0
5
4
3
2
1
0
PTADD51
PTADD42
PTADD3
PTADD2
PTADD1
PTADD0
0
0
0
0
0
0
W
Reset:
0
0
1
PTADD5 has no effect on the input-only PTA5 pin. Read this bit is always equal to zero.
2
PTADD4 has no effect on the output-only PTA4 pin.
Figure 6-3. Port A Data Direction 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.
6.4.2
Port A Control Registers
The pins associated with port A are controlled by the registers in this section. These registers control the
pin pullup, slew rate and drive strength of the Port A pins independent of the parallel I/O register.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
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Chapter 6 Parallel Input/Output Control
6.4.2.1
Port A Internal Pullup Enable (PTAPE)
An internal pullup device can be enabled for each port pin by setting the corresponding bit in the pullup
enable register (PTAPEn). 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.
R
7
6
0
0
5
4
3
2
1
0
PTAPE5
PTAPE41
PTAPE3
PTAPE2
PTAPE1
PTAPE0
0
0
0
0
0
0
W
Reset:
1
0
0
PTAPE4 has no effect on the output-only PTA4 pin.
Figure 6-4. Internal Pullup Enable for Port A Register (PTAPE)
Table 6-3. PTAPE 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.
6.4.2.2
Port A Slew Rate Enable (PTASE)
Slew rate control can be enabled for each port pin by setting the corresponding bit in the slew rate control
register (PTASEn). 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.
R
7
6
0
0
5
4
3
2
1
0
PTASE51
PTASE4
PTASE3
PTASE2
PTASE1
PTASE0
1
1
1
1
1
1
W
Reset:
1
0
0
PTASE5 has no effect on the input-only PTA5 pin.
Figure 6-5. Slew Rate Enable for Port A Register (PTASE)
Table 6-4. PTASE Register Field Descriptions
Field
Description
5:0
Output Slew Rate Enable for Port A Bits — Each of these control bits determines if the output slew rate control
PTASE[5:0] 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.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
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Chapter 6 Parallel Input/Output Control
6.4.2.3
Port A Drive Strength Select (PTADS)
An output pin can be selected to have high output drive strength by setting the corresponding bit in the
drive strength select register (PTADSn). 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.
6.4.2.4
R
Port A Drive Strength Select (PTADS)
7
6
0
0
5
4
3
2
1
0
PTADS51
PTADS4
PTADS3
PTADS2
PTADS1
PTADS0
0
0
0
0
0
0
W
Reset:
1
0
0
PTADS5 has no effect on the input-only PTA5 pin.
Figure 6-6. Drive Strength Selection for Port A Register (PTADS)
Table 6-5. PTADS 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. For port A pins that are configured as inputs, these bits have no effect.
0 Low output drive strength selected for port A bit n.
1 High output drive strength selected for port A bit n.
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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
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Chapter 7 Central Processor Unit (S08CPUV2)
7.2
Programmer’s Model and CPU Registers
Figure 7-1 shows the five CPU registers. CPU registers are not part of the memory map.
7
0
ACCUMULATOR
A
16-BIT INDEX REGISTER H:X
H INDEX REGISTER (HIGH)
8
15
INDEX REGISTER (LOW)
7
X
0
SP
STACK POINTER
0
15
PROGRAM COUNTER
7
0
CONDITION CODE REGISTER V 1 1 H I N Z C
PC
CCR
CARRY
ZERO
NEGATIVE
INTERRUPT MASK
HALF-CARRY (FROM BIT 3)
TWO’S COMPLEMENT OVERFLOW
Figure 7-1. CPU Registers
7.2.1
Accumulator (A)
The A accumulator is a general-purpose 8-bit register. One operand input to the arithmetic logic unit
(ALU) is connected to the accumulator and the ALU results are often stored into the A accumulator after
arithmetic and logical operations. The accumulator can be loaded from memory using various addressing
modes to specify the address where the loaded data comes from, or the contents of A can be stored to
memory using various addressing modes to specify the address where data from A will be stored.
Reset has no effect on the contents of the A accumulator.
7.2.2
Index Register (H:X)
This 16-bit register is actually two separate 8-bit registers (H and X), which often work together as a 16-bit
address pointer where H holds the upper byte of an address and X holds the lower byte of the address. All
indexed addressing mode instructions use the full 16-bit value in H:X as an index reference pointer;
however, for compatibility with the earlier M68HC05 Family, some instructions operate only on the
low-order 8-bit half (X).
Many instructions treat X as a second general-purpose 8-bit register that can be used to hold 8-bit data
values. X can be cleared, incremented, decremented, complemented, negated, shifted, or rotated. Transfer
instructions allow data to be transferred from A or transferred to A where arithmetic and logical operations
can then be performed.
For compatibility with the earlier M68HC05 Family, H is forced to 0x00 during reset. Reset has no effect
on the contents of X.
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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.
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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
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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.
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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.
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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 should return after servicing the interrupt. The CPU responds to an interrupt by performing the
same sequence of operations as for a software interrupt (SWI) instruction, except the address used for the
vector fetch is determined by the highest priority interrupt that is pending when the interrupt sequence
started.
The CPU sequence for an interrupt is:
1. Store the contents of PCL, PCH, X, A, and CCR on the stack, in that order.
2. Set the I bit in the CCR.
3. Fetch the high-order half of the interrupt vector.
4. Fetch the low-order half of the interrupt vector.
5. Delay for one free bus cycle.
6. Fetch three bytes of program information starting at the address indicated by the interrupt vector
to fill the instruction queue in preparation for execution of the first instruction in the interrupt
service routine.
After the CCR contents are pushed onto the stack, the I bit in the CCR is set to prevent other interrupts
while in the interrupt service routine. Although it is possible to clear the I bit with an instruction in the
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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.
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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.
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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.
Table 7-2. Instruction Set Summary (Sheet 1 of 9)
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
Add with Carry
A ← (A) + (M) + (C)
Add without Carry
A ← (A) + (M)
Object Code
Cycles
Operation
Address
Mode
Source
Form
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
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
–
–– – – – –
MC9S08QD4 Series MCU Data Sheet, Rev. 3
84
Freescale Semiconductor
Chapter 7 Central Processor Unit (S08CPUV2)
Table 7-2. Instruction Set Summary (Sheet 2 of 9)
Object Code
Cycles
Operation
Address
Mode
Source
Form
Cyc-by-Cyc
Details
Affect
on CCR
VH I N Z C
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
–– – – – –
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
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
–– – – – –
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
85
Chapter 7 Central Processor Unit (S08CPUV2)
Table 7-2. Instruction Set Summary (Sheet 3 of 9)
BRA rel
Branch Always (if I = 1)
BRCLR n,opr8a,rel
DIR (b0)
DIR (b1)
DIR (b2)
DIR (b3)
Branch if Bit n in Memory Clear (if (Mn) = 0)
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
Branch if (A) = (M)
Branch if (A) = (M)
Branch if (X) = (M)
Branch if (A) = (M)
Branch if (A) = (M)
Branch if (A) = (M)
REL
Object Code
Cycles
Operation
Address
Mode
Source
Form
DIR
IMM
IMM
IX1+
IX+
SP1
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
–– – – – –
20 rr
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–
M ← $00
A ← $00
X ← $00
H ← $00
M ← $00
M ← $00
M ← $00
31
41
51
61
71
9E 61
dd
ii
ii
ff
rr
ff
rr
rr
rr
rr
rr
MC9S08QD4 Series MCU Data Sheet, Rev. 3
86
Freescale Semiconductor
Chapter 7 Central Processor Unit (S08CPUV2)
Table 7-2. Instruction Set Summary (Sheet 4 of 9)
CMP
CMP
CMP
CMP
CMP
CMP
CMP
CMP
#opr8i
opr8a
opr16a
oprx16,X
oprx8,X
,X
oprx16,SP
oprx8,SP
Compare Accumulator with Memory
A–M
(CCR Updated But Operands Not Changed)
Object Code
Cycles
Operation
Address
Mode
Source
Form
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
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
5
1
1
5
4
6
rfwpp
p
p
rfwpp
rfwp
prfwpp
0– –
– –
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
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
–
–
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
87
Chapter 7 Central Processor Unit (S08CPUV2)
Table 7-2. Instruction Set Summary (Sheet 5 of 9)
INC opr8a
INCA
INCX
INC oprx8,X
INC ,X
INC oprx8,SP
Increment
M ← (M) + $01
A ← (A) + $01
X ← (X) + $01
M ← (M) + $01
M ← (M) + $01
M ← (M) + $01
Object Code
Cycles
Operation
Address
Mode
Source
Form
Cyc-by-Cyc
Details
Affect
on CCR
VH I N Z C
5
1
1
5
4
6
rfwpp
p
p
rfwpp
rfwp
prfwpp
dd
hh ll
ee ff
ff
3
4
4
3
3
ppp
pppp
pppp
ppp
ppp
–– – – – –
DIR
INH
INH
IX1
IX
SP1
3C dd
4C
5C
6C ff
7C
9E 6C ff
BC
CC
DC
EC
FC
– –
–
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
MC9S08QD4 Series MCU Data Sheet, Rev. 3
88
Freescale Semiconductor
Chapter 7 Central Processor Unit (S08CPUV2)
Table 7-2. Instruction Set Summary (Sheet 6 of 9)
Object Code
Cycles
Operation
Address
Mode
Source
Form
VH I N Z C
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– –
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
#opr8i
opr8a
opr16a
oprx16,X
oprx8,X
,X
oprx16,SP
oprx8,SP
Affect
on CCR
5
5
4
5
MOV opr8a,opr8a
MOV opr8a,X+
MOV #opr8i,opr8a
MOV ,X+,opr8a
ORA
ORA
ORA
ORA
ORA
ORA
ORA
ORA
Cyc-by-Cyc
Details
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
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
89
Chapter 7 Central Processor Unit (S08CPUV2)
Table 7-2. Instruction Set Summary (Sheet 7 of 9)
Object Code
Cycles
Operation
Address
Mode
Source
Form
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
–
MC9S08QD4 Series MCU Data Sheet, Rev. 3
90
Freescale Semiconductor
Chapter 7 Central Processor Unit (S08CPUV2)
Table 7-2. Instruction Set Summary (Sheet 8 of 9)
Object Code
Cycles
Operation
Address
Mode
Source
Form
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– –
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
VH I N Z C
pp
rpp
prpp
prpp
rpp
rfp
pprpp
prpp
A0
B0
C0
D0
E0
F0
9E D0
9E E0
#opr8i
opr8a
opr16a
oprx16,X
oprx8,X
,X
oprx16,SP
oprx8,SP
Affect
on CCR
2
3
4
4
3
3
5
4
IMM
DIR
EXT
IX2
IX1
IX
SP2
SP1
SUB
SUB
SUB
SUB
SUB
SUB
SUB
SUB
Cyc-by-Cyc
Details
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
–– – – – –
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
91
Chapter 7 Central Processor Unit (S08CPUV2)
Table 7-2. Instruction Set Summary (Sheet 9 of 9)
Object Code
Cycles
Operation
Address
Mode
Source
Form
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
MC9S08QD4 Series MCU Data Sheet, Rev. 3
92
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
ROL
INH 2
1 6A
Relative
Indexed, No Offset
Indexed, 8-Bit Offset
Indexed, 16-Bit Offset
IMM to DIR
DIR to IX+
INH 2
4 6B
DBNZ
DBNZ
INC
IX1 1
4 7D
CLRX
IX1 1
CLR
ADD
INH 2
1
Stack Pointer, 8-Bit Offset
Stack Pointer, 16-Bit Offset
Indexed, No Offset with
Post Increment
Indexed, 1-Byte Offset with
Post Increment
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
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
IX1 2
5 7C
TST
INH 2
5 6E
IX1+
DEC
INC
INH 2
1 6D
PSHX
IX 1
4 8A
IX1 1
7 7B
INH 3
1 6C
SP1
SP2
IX+
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
DEC
DD 2
DIX+ 3
1 5F
1 6F
INH 1
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
MOV
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
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
93
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
MC9S08QD4 Series MCU Data Sheet, Rev. 3
94
Freescale Semiconductor
Chapter 8
Analog-to-Digital Converter (ADC10V1)
8.1
Introduction
The 10-bit analog-to-digital converter (ADC) is a successive approximation ADC designed for operation
within an integrated microcontroller system-on-chip.
The ADC module design supports up to 28 separate analog inputs (AD0–AD27). Only four
(ADC1P0–ADC1P3) of the possible inputs are implemented on the MC9S08QD4 series MCU. These
inputs are selected by the ADCH bits.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
95
Chapter 8 Analog-to-Digital Converter (ADC10V1)
BKGD/MS
IRQ
HCS08 CORE
BDC
HCS08 SYSTEM CONTROL
RESETS AND INTERRUPTS
MODES OF OPERATION
POWER MANAGEMENT
RTI
COP
IRQ
LVD
4-BIT KEYBOARD
INTERRUPT MODULE (KBI)
4
TPM2CH0
1-CH 16-BIT TIMER/PWM
MODULE (TPM2)
TCLK2
2-CH 16-BIT TIMER/PWM
MODULE (TPM1)
TPM1CH0
TPM1CH1
TCLK1
USER FLASH
4096 / 2048 BYTES
10-BIT
ANALOG-TO-DIGITAL
CONVERTER (ADC)
PORT A
CPU
PTA5/TPM2CH0I/IRQ/RESET
PTA4/TPM2CH0O/BKGD/MS
PTA3/KBI1P3/TCLK2/ADC1P3
PTA2/KBI1P2/TCLK1/ADC1P2
PTA1/KBI1P1/TPM1CH1/ADC1P1
PTA0/KBI1P0/TPM1CH0/ADC1P0
4
USER RAM
256 / 128 BYTES
16 MHz INTERNAL CLOCK
SOURCE (ICS)
VSS
VDD
VOLTAGE REGULATOR
VDDA
VSSA
VREFH
VREFL
NOTES:
1 Port pins are software configurable with pullup device if input port.
2 Port pins are software configurable for output drive strength.
3
Port pins are software configurable for output slew rate control.
4 IRQ contains a software configurable (IRQPDD) pullup/pulldown device if PTA5 enabled as IRQ pin function (IRQPE = 1).
5 RESET contains integrated pullup device if PTA5 enabled as reset pin function (RSTPE = 1).
6
PTA5 does not contain a clamp diode to VDD and must not be driven above VDD. The voltage measured on this pin when
internal pullup is enabled may be as low as VDD – 0.7 V. The internal gates connected to this pin are pulled to VDD.
7
PTA4 contains integrated pullup device if BKGD enabled (BKGDPE = 1).
8 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.
Figure 8-1. MC9S08QD4 Series Block Diagram Highlighting ADC Block and Pins
8.1.1
Module Configurations
This section provides device-specific information for configuring the ADC on MC9S08QD4 series.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
96
Freescale Semiconductor
Chapter 8 Analog-to-Digital Converter (ADC10V1)
8.1.1.1
Channel Assignments
The ADC channel assignments for the MC9S08QD4 series devices are shown in Table 8-1. Reserved
channels convert to an unknown value.
Table 8-1. ADC Channel Assignment
1
2
ADCH
Channel
Input
Pin Control
ADCH
Channel
Input
Pin Control
00000
AD0
PTA0/ADC1P0
ADPC0
10000
AD16
VSS
N/A
00001
AD1
PTA1/ADC1P1
ADPC1
10001
AD17
VSS
N/A
00010
AD2
PTA2/ADC1P2
ADPC2
10010
AD18
VSS
N/A
00011
AD3
PTA3/ADC1P3
ADPC3
10011
AD19
VSS
N/A
00100
AD4
Vss
N/A
10100
AD20
VSS
N/A
00101
AD5
Vss
N/A
10101
AD21
VSS
N/A
00110
AD6
Vss
N/A
10110
AD22
Reserved
N/A
00111
AD7
Vss
N/A
10111
AD23
Reserved
N/A
01000
AD8
VSS
N/A
11000
AD24
Reserved
N/A
01001
AD9
VSS
N/A
11001
AD25
Reserved
N/A
01010
AD10
VSS
N/A
11010
AD26
Temperature
Sensor1
N/A
01011
AD11
VSS
N/A
11011
AD27
Internal Bandgap2
N/A
01100
AD12
VSS
N/A
11100
VREFH
VDD
N/A
01101
AD13
VSS
N/A
11101
VREFH
VDD
N/A
01110
AD14
VSS
N/A
11110
VREFL
VSS
N/A
01111
AD15
VSS
N/A
11111
Module
Disabled
None
N/A
For information, see Section 8.1.1.5, “Temperature Sensor.”
Requires BGBE =1 in SPMSC1 see Section 5.8.8, “System Power Management Status and Control 1 Register (SPMSC1).”
For value of bandgap voltage reference see Appendix A.5, “DC Characteristics.”
8.1.1.2
Alternate Clock
The ADC is capable of performing conversions using the MCU bus clock, the bus clock divided by two,
or the local asynchronous clock (ADACK) within the module. The alternate clock, ALTCLK, input for the
MC9S08QD4 series MCU devices is not implemented.
8.1.1.3
Hardware Trigger
The ADC hardware trigger, ADHWT, is output from the real-time interrupt (RTI) counter. The RTI counter
can be clocked by either ICSERCLK or a nominal 32 kHz clock source within the RTI block.
The period of the RTI is determined by the input clock frequency and the RTIS bits. The RTI counter is a
free running counter that generates an overflow at the RTI rate determined by the RTIS bits. When the
ADC hardware trigger is enabled, a conversion is initiated upon a RTI counter overflow.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
97
Chapter 8 Analog-to-Digital Converter (ADC10V1)
The RTI can be configured to cause a hardware trigger in MCU run, wait, and stop3.
8.1.1.4
Analog Pin Enables
The ADC on MC9S08QD4 contains only one analog pin enable register, APCTL1.
8.1.1.5
Temperature Sensor
To use the on-chip temperature sensor, the user must perform the following:
• Configure ADC for long sample with a maximum of 1 MHz clock
• Convert the bandgap voltage reference channel (AD27)
— By converting the digital value of the bandgap voltage reference channel using the value of
VBG the user can determine VDD. For value of bandgap voltage, see Appendix A.5, “DC
Characteristics”.
• Convert the temperature sensor channel (AD26)
— By using the calculated value of VDD, convert the digital value of AD26 into a voltage, VTEMP
Equation 8-1 provides an approximate transfer function of the on-chip temperature sensor for VDD = 3.0V,
Temp = 25°C, using the ADC at fADCK = 1.0 MHz and configured for long sample.
TempC = 25 – ((VTEMP – 1.3894) / ( 0.0033))
Eqn. 8-1
0.0017 is the uncalibrated voltage versus temperature slope in V/°C. Uncalibrated accuracy of the
temperature sensor is approximately ± 12°C, using Equation 8-1.
To improve accuracy the user must calibrate the bandgap voltage reference and temperature sensor.
Calibrating at 25°C will improve accuracy to ± 4.5°C.
Calibration at 3 points, -40°C, 25°C and 105°C will improve accuracy to ± 2.5°C. Once calibration has
been completed, the user will need to calculate the slope for both hot and cold. In application code, the
user would then calculate the temperature using Equation 8-1 as detailed above and then determine if the
temperature is above or below 25°C. Once determined if the temperature is above or below 25°C, the user
can recalculate the temperature using the hot or cold slope value obtained during calibration.
8.1.1.6
Low-Power Mode Operation
The ADC is capable of running in stop3 mode but requires LVDSE in SPMSC1 to be set.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
98
Freescale Semiconductor
Analog-to-Digital Converter (S08ADC10V1)
8.1.2
Features
Features of the ADC module include:
• Linear successive approximation algorithm with 10 bits resolution.
• Up to 28 analog inputs.
• Output formatted in 10- or 8-bit right-justified format.
• Single or continuous conversion (automatic return to idle after single conversion).
• Configurable sample time and conversion speed/power.
• Conversion complete flag and interrupt.
• Input clock selectable from up to four sources.
• Operation in wait or stop3 modes for lower noise operation.
• Asynchronous clock source for lower noise operation.
• Selectable asynchronous hardware conversion trigger.
• Automatic compare with interrupt for less-than, or greater-than or equal-to, programmable value.
8.1.3
Block Diagram
Figure 8-2 provides a block diagram of the ADC module
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
99
Analog-to-Digital Converter (S08ADC10V1)
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
sample
initialize
•••
AD0
convert
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 8-2. ADC Block Diagram
8.2
External Signal Description
The ADC module supports up to 28 separate analog inputs. It also requires four supply/reference/ground
connections.
Table 8-2. Signal Properties
Name
Function
AD27–AD0
Analog Channel inputs
VREFH
High reference voltage
VREFL
Low reference voltage
VDDAD
Analog power supply
VSSAD
Analog ground
MC9S08QD4 Series MCU Data Sheet, Rev. 3
100
Freescale Semiconductor
Analog-to-Digital Converter (S08ADC10V1)
8.2.1
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.
8.2.2
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.
8.2.3
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 that is between the minimum VDDAD spec and the VDDAD potential (VREFH
must never exceed VDDAD).
8.2.4
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.
8.2.5
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.
8.3
Register Definition
These memory mapped registers control and monitor operation of the ADC:
•
•
•
•
•
•
8.3.1
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 enable registers, APCTL1, APCTL2, APCTL3
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).
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
101
Analog-to-Digital Converter (S08ADC10V1)
7
R
6
5
4
AIEN
ADCO
0
0
3
2
1
0
1
1
COCO
ADCH
W
Reset:
0
1
1
1
= Unimplemented or Reserved
Figure 8-3. Status and Control Register (ADCSC1)
Table 8-3. ADCSC1 Register Field Descriptions
Field
Description
7
COCO
Conversion Complete Flag — The COCO flag is a read-only bit which is set each time a conversion is
completed when the compare function is disabled (ACFE = 0). When the compare function is enabled (ACFE =
1) the COCO flag is set upon completion of a conversion only if the compare result is true. This bit is cleared
whenever ADCSC1 is written or whenever ADCRL is read.
0 Conversion not completed
1 Conversion completed
6
AIEN
Interrupt Enable — AIEN is used to enable conversion complete interrupts. When COCO becomes set while
AIEN is high, an interrupt is asserted.
0 Conversion complete interrupt disabled
1 Conversion complete interrupt enabled
5
ADCO
Continuous Conversion Enable — ADCO is used to enable continuous conversions.
0 One conversion following a write to the 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 which is used to select one of the input channels. The
input channels are detailed in Figure 8-4.
The successive approximation converter subsystem is turned off when the channel select bits are all set to 1.
This feature allows for explicit disabling of the ADC and isolation of the input channel from all sources.
Terminating continuous conversions this way will prevent an additional, single conversion from being performed.
It is not necessary to set the channel select bits to all 1s to place the ADC in a low-power state when continuous
conversions are not enabled because the module automatically enters a low-power state when a conversion
completes.
Figure 8-4. Input Channel Select
ADCH
Input Select
ADCH
Input Select
00000
AD0
10000
AD16
00001
AD1
10001
AD17
00010
AD2
10010
AD18
00011
AD3
10011
AD19
00100
AD4
10100
AD20
00101
AD5
10101
AD21
00110
AD6
10110
AD22
MC9S08QD4 Series MCU Data Sheet, Rev. 3
102
Freescale Semiconductor
Analog-to-Digital Converter (S08ADC10V1)
Figure 8-4. Input Channel Select (continued)
8.3.2
ADCH
Input Select
ADCH
Input Select
00111
AD7
10111
AD23
01000
AD8
11000
AD24
01001
AD9
11001
AD25
01010
AD10
11010
AD26
01011
AD11
11011
AD27
01100
AD12
11100
Reserved
01101
AD13
11101
VREFH
01110
AD14
11110
VREFL
01111
AD15
11111
Module disabled
Status and Control Register 2 (ADCSC2)
The ADCSC2 register is used to control the compare function, conversion trigger and conversion active
of the ADC module.
7
R
6
5
4
ADTRG
ACFE
ACFGT
0
0
0
ADACT
3
2
0
0
0
0
1
0
R1
R1
0
0
W
Reset:
0
= Unimplemented or Reserved
1
Bits 1 and 0 are reserved bits that must always be written to 0.
Figure 8-5. Status and Control Register 2 (ADCSC2)
Table 8-4. ADCSC2 Register Field Descriptions
Field
Description
7
ADACT
Conversion Active — ADACT indicates that a conversion is in progress. ADACT is set when a conversion is
initiated and cleared when a conversion is completed or aborted.
0 Conversion not in progress
1 Conversion in progress
6
ADTRG
Conversion Trigger Select — ADTRG is used to select the type of trigger to be used for initiating a conversion.
Two types of trigger are selectable: software trigger and hardware trigger. When software trigger is selected, a
conversion is initiated following a write to 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
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
103
Analog-to-Digital Converter (S08ADC10V1)
Table 8-4. ADCSC2 Register Field Descriptions (continued)
Field
Description
5
ACFE
Compare Function Enable — ACFE is used to enable the compare function.
0 Compare function disabled
1 Compare function enabled
4
ACFGT
Compare Function Greater Than Enable — ACFGT is used to configure the compare function to trigger when
the result of the conversion of the input being monitored is greater than or equal to the compare value. The
compare function defaults to triggering when the result of the compare of the input being monitored is less than
the compare value.
0 Compare triggers when input is less than compare level
1 Compare triggers when input is greater than or equal to compare level
8.3.3
Data Result High Register (ADCRH)
ADCRH contains the upper two bits of the result of a 10-bit conversion. When configured for 8-bit
conversions both ADR8 and ADR9 are equal to zero. ADCRH is updated each time a conversion
completes except when automatic compare is enabled and the compare condition is not met. In 10-bit
MODE, reading 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, then the
intermediate conversion result will be lost. In 8-bit mode there is no interlocking with ADCRL. In the case
that the MODE bits are changed, any data in ADCRH becomes invalid.
R
7
6
5
4
3
2
1
0
0
0
0
0
0
0
ADR9
ADR8
0
0
0
0
0
0
0
0
W
Reset:
= Unimplemented or Reserved
Figure 8-6. Data Result High Register (ADCRH)
8.3.4
Data Result Low Register (ADCRL)
ADCRL contains the lower eight bits of the result of a 10-bit conversion, and all eight bits of an 8-bit
conversion. This register is updated each time a conversion completes except when automatic compare is
enabled and the compare condition is not met. In 10-bit mode, reading 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, then the intermediate conversion results will be lost. In
8-bit mode, there is no interlocking with ADCRH. In the case that the MODE bits are changed, any data
in ADCRL becomes invalid.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
104
Freescale Semiconductor
Analog-to-Digital Converter (S08ADC10V1)
R
7
6
5
4
3
2
1
0
ADR7
ADR6
ADR5
ADR4
ADR3
ADR2
ADR1
ADR0
0
0
0
0
0
0
0
0
W
Reset:
= Unimplemented or Reserved
Figure 8-7. Data Result Low Register (ADCRL)
8.3.5
Compare Value High Register (ADCCVH)
This register holds the upper two bits of the 10-bit compare value. These bits are compared to the upper
two bits of the result following a conversion in 10-bit mode when the compare function is enabled.In 8-bit
operation, ADCCVH is not used during compare.
R
7
6
5
4
0
0
0
0
3
2
1
0
ADCV9
ADCV8
0
0
W
Reset:
0
0
0
0
0
0
= Unimplemented or Reserved
Figure 8-8. Compare Value High Register (ADCCVH)
8.3.6
Compare Value Low Register (ADCCVL)
This register holds the lower 8 bits of the 10-bit compare value, or all 8 bits of the 8-bit compare value.
Bits ADCV7:ADCV0 are compared to the lower 8 bits of the result following a conversion in either 10-bit
or 8-bit mode.
7
6
5
4
3
2
1
0
ADCV7
ADCV6
ADCV5
ADCV4
ADCV3
ADCV2
ADCV1
ADCV0
0
0
0
0
0
0
0
0
R
W
Reset:
Figure 8-9. Compare Value Low Register(ADCCVL)
8.3.7
Configuration Register (ADCCFG)
ADCCFG is used to select the mode of operation, clock source, clock divide, and configure for low power
or long sample time.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
105
Analog-to-Digital Converter (S08ADC10V1)
7
6
5
4
3
2
1
0
R
ADLPC
ADIV
ADLSMP
MODE
ADICLK
W
Reset:
0
0
0
0
0
0
0
0
Figure 8-10. Configuration Register (ADCCFG)
Table 8-5. ADCCFG Register Field Descriptions
Field
Description
7
ADLPC
Low Power Configuration — ADLPC controls the speed and power configuration of the successive
approximation converter. This is used to optimize power consumption when higher sample rates are not required.
0 High speed configuration
1 Low power configuration: {FC31}The power is reduced at the expense of maximum clock speed.
6:5
ADIV
Clock Divide Select — ADIV select the divide ratio used by the ADC to generate the internal clock ADCK.
Table 8-6 shows the available clock configurations.
4
ADLSMP
Long Sample Time Configuration — ADLSMP selects between long and short sample time. This adjusts the
sample period to allow higher impedance inputs to be accurately sampled or to maximize conversion speed for
lower impedance inputs. Longer sample times can also be used to lower overall power consumption when
continuous conversions are enabled if high conversion rates are not required.
0 Short sample time
1 Long sample time
3:2
MODE
Conversion Mode Selection — MODE bits are used to select between 10- or 8-bit operation. See Table 8-7.
1:0
ADICLK
Input Clock Select — ADICLK bits select the input clock source to generate the internal clock ADCK. See
Table 8-8.
Table 8-6. Clock Divide Select
ADIV
Divide Ratio
Clock Rate
00
1
Input clock
01
2
Input clock ÷ 2
10
4
Input clock ÷ 4
11
8
Input clock ÷ 8
Table 8-7. Conversion Modes
MODE
Mode Description
00
8-bit conversion (N=8)
01
Reserved
10
10-bit conversion (N=10)
11
Reserved
MC9S08QD4 Series MCU Data Sheet, Rev. 3
106
Freescale Semiconductor
Analog-to-Digital Converter (S08ADC10V1)
Table 8-8. Input Clock Select
ADICLK
Selected Clock Source
00
8.3.8
Bus clock
01
Bus clock divided by 2
10
Alternate clock (ALTCLK)
11
Asynchronous clock (ADACK)
Pin Control 1 Register (APCTL1)
The pin control registers are used to disable the I/O port control of MCU pins used as analog inputs.
APCTL1 is used to control the pins associated with channels 0–7 of the ADC module.
7
6
5
4
3
2
1
0
ADPC7
ADPC6
ADPC5
ADPC4
ADPC3
ADPC2
ADPC1
ADPC0
0
0
0
0
0
0
0
0
R
W
Reset:
Figure 8-11. Pin Control 1 Register (APCTL1)
Table 8-9. APCTL1 Register Field Descriptions
Field
Description
7
ADPC7
ADC Pin Control 7 — ADPC7 is used to control the pin associated with channel AD7.
0 AD7 pin I/O control enabled
1 AD7 pin I/O control disabled
6
ADPC6
ADC Pin Control 6 — ADPC6 is used to control the pin associated with channel AD6.
0 AD6 pin I/O control enabled
1 AD6 pin I/O control disabled
5
ADPC5
ADC Pin Control 5 — ADPC5 is used to control the pin associated with channel AD5.
0 AD5 pin I/O control enabled
1 AD5 pin I/O control disabled
4
ADPC4
ADC Pin Control 4 — ADPC4 is used to control the pin associated with channel AD4.
0 AD4 pin I/O control enabled
1 AD4 pin I/O control disabled
3
ADPC3
ADC Pin Control 3 — ADPC3 is used to control the pin associated with channel AD3.
0 AD3 pin I/O control enabled
1 AD3 pin I/O control disabled
2
ADPC2
ADC Pin Control 2 — ADPC2 is used to control the pin associated with channel AD2.
0 AD2 pin I/O control enabled
1 AD2 pin I/O control disabled
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
107
Analog-to-Digital Converter (S08ADC10V1)
Table 8-9. APCTL1 Register Field Descriptions (continued)
Field
Description
1
ADPC1
ADC Pin Control 1 — ADPC1 is used to control the pin associated with channel AD1.
0 AD1 pin I/O control enabled
1 AD1 pin I/O control disabled
0
ADPC0
ADC Pin Control 0 — ADPC0 is used to control the pin associated with channel AD0.
0 AD0 pin I/O control enabled
1 AD0 pin I/O control disabled
8.3.9
Pin Control 2 Register (APCTL2)
APCTL2 is used to control channels 8–15 of the ADC module.
7
6
5
4
3
2
1
0
ADPC15
ADPC14
ADPC13
ADPC12
ADPC11
ADPC10
ADPC9
ADPC8
0
0
0
0
0
0
0
0
R
W
Reset:
Figure 8-12. Pin Control 2 Register (APCTL2)
Table 8-10. APCTL2 Register Field Descriptions
Field
Description
7
ADPC15
ADC Pin Control 15 — ADPC15 is used to control the pin associated with channel AD15.
0 AD15 pin I/O control enabled
1 AD15 pin I/O control disabled
6
ADPC14
ADC Pin Control 14 — ADPC14 is used to control the pin associated with channel AD14.
0 AD14 pin I/O control enabled
1 AD14 pin I/O control disabled
5
ADPC13
ADC Pin Control 13 — ADPC13 is used to control the pin associated with channel AD13.
0 AD13 pin I/O control enabled
1 AD13 pin I/O control disabled
4
ADPC12
ADC Pin Control 12 — ADPC12 is used to control the pin associated with channel AD12.
0 AD12 pin I/O control enabled
1 AD12 pin I/O control disabled
3
ADPC11
ADC Pin Control 11 — ADPC11 is used to control the pin associated with channel AD11.
0 AD11 pin I/O control enabled
1 AD11 pin I/O control disabled
2
ADPC10
ADC Pin Control 10 — ADPC10 is used to control the pin associated with channel AD10.
0 AD10 pin I/O control enabled
1 AD10 pin I/O control disabled
MC9S08QD4 Series MCU Data Sheet, Rev. 3
108
Freescale Semiconductor
Analog-to-Digital Converter (S08ADC10V1)
Table 8-10. APCTL2 Register Field Descriptions (continued)
Field
Description
1
ADPC9
ADC Pin Control 9 — ADPC9 is used to control the pin associated with channel AD9.
0 AD9 pin I/O control enabled
1 AD9 pin I/O control disabled
0
ADPC8
ADC Pin Control 8 — ADPC8 is used to control the pin associated with channel AD8.
0 AD8 pin I/O control enabled
1 AD8 pin I/O control disabled
8.3.10
Pin Control 3 Register (APCTL3)
APCTL3 is used to control channels 16–23 of the ADC module.
7
6
5
4
3
2
1
0
ADPC23
ADPC22
ADPC21
ADPC20
ADPC19
ADPC18
ADPC17
ADPC16
0
0
0
0
0
0
0
0
R
W
Reset:
Figure 8-13. Pin Control 3 Register (APCTL3)
Table 8-11. APCTL3 Register Field Descriptions
Field
Description
7
ADPC23
ADC Pin Control 23 — ADPC23 is used to control the pin associated with channel AD23.
0 AD23 pin I/O control enabled
1 AD23 pin I/O control disabled
6
ADPC22
ADC Pin Control 22 — ADPC22 is used to control the pin associated with channel AD22.
0 AD22 pin I/O control enabled
1 AD22 pin I/O control disabled
5
ADPC21
ADC Pin Control 21 — ADPC21 is used to control the pin associated with channel AD21.
0 AD21 pin I/O control enabled
1 AD21 pin I/O control disabled
4
ADPC20
ADC Pin Control 20 — ADPC20 is used to control the pin associated with channel AD20.
0 AD20 pin I/O control enabled
1 AD20 pin I/O control disabled
3
ADPC19
ADC Pin Control 19 — ADPC19 is used to control the pin associated with channel AD19.
0 AD19 pin I/O control enabled
1 AD19 pin I/O control disabled
2
ADPC18
ADC Pin Control 18 — ADPC18 is used to control the pin associated with channel AD18.
0 AD18 pin I/O control enabled
1 AD18 pin I/O control disabled
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
109
Analog-to-Digital Converter (S08ADC10V1)
Table 8-11. APCTL3 Register Field Descriptions (continued)
Field
Description
1
ADPC17
ADC Pin Control 17 — ADPC17 is used to control the pin associated with channel AD17.
0 AD17 pin I/O control enabled
1 AD17 pin I/O control disabled
0
ADPC16
ADC Pin Control 16 — ADPC16 is used to control the pin associated with channel AD16.
0 AD16 pin I/O control enabled
1 AD16 pin I/O control disabled
8.4
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. The
selected channel voltage is converted by a successive approximation algorithm into an 11-bit digital result.
In 8-bit mode, the selected channel voltage is converted by a successive approximation algorithm into a
9-bit digital result.
When the conversion is completed, the result is placed in the data registers (ADCRH and ADCRL).In
10-bit mode, the result is rounded to 10 bits and placed in 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
in conjunction with any of the conversion modes and configurations.
8.4.1
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 2. For higher bus clock rates, this allows a maximum divide by 16 of the
bus clock.
ALTCLK, as defined for this MCU (See module section introduction).
The asynchronous clock (ADACK) – This clock is generated from a clock source within the ADC
module. When selected as the clock source this clock remains active while the MCU is in wait or
stop3 mode and allows conversions in these modes for lower noise operation.
Whichever clock is selected, its frequency must fall within the specified frequency range for ADCK. If the
available clocks are too slow, the ADC will not perform according to specifications. If the available clocks
MC9S08QD4 Series MCU Data Sheet, Rev. 3
110
Freescale Semiconductor
Analog-to-Digital Converter (S08ADC10V1)
are too fast, then the clock must be divided to the appropriate frequency. This divider is specified by the
ADIV bits and can be divide-by 1, 2, 4, or 8.
8.4.2
Input Select and Pin Control
The pin control registers (APCTL3, APCTL2, and APCTL1) are used to disable the I/O port control of the
pins used as analog inputs.When a pin control register bit is set, the following conditions are forced for the
associated MCU pin:
• The output buffer is forced to its high impedance state.
• The input buffer is disabled. A read of the I/O port returns a zero for any pin with its input buffer
disabled.
• The pullup is disabled.
8.4.3
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.
8.4.4
Conversion Control
Conversions can be performed in either 10-bit mode or 8-bit mode as determined by the MODE bits.
Conversions can be initiated by either a software or hardware trigger. In addition, the ADC module can be
configured for low power operation, long sample time, continuous conversion, and automatic compare of
the conversion result to a software determined compare value.
8.4.4.1
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.
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.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
111
Analog-to-Digital Converter (S08ADC10V1)
8.4.4.2
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 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.
8.4.4.3
Aborting Conversions
Any conversion in progress will be 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 but
continue to be the values transferred after the completion of the last successful conversion. In the case that
the conversion was aborted by a reset, ADCRH and ADCRL return to their reset states.
8.4.4.4
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).
8.4.4.5
Total Conversion Time
The total conversion time depends on the sample time (as determined by ADLSMP), the MCU bus
frequency, the conversion mode (8-bit or 10-bit), and the frequency of the conversion clock (fADCK). After
the module becomes active, sampling of the input begins. ADLSMP is used to select between short and
long sample times.When sampling is complete, the converter is isolated from the input channel and a
successive approximation algorithm is performed to determine the digital value of the analog signal. The
MC9S08QD4 Series MCU Data Sheet, Rev. 3
112
Freescale Semiconductor
Analog-to-Digital Converter (S08ADC10V1)
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 8-12.
Table 8-12. Total Conversion Time vs. Control Conditions
Conversion Type
ADICLK
ADLSMP
Max Total Conversion Time
Single or first continuous 8-bit
0x, 10
0
20 ADCK cycles + 5 bus clock cycles
Single or first continuous 10-bit
0x, 10
0
23 ADCK cycles + 5 bus clock cycles
Single or first continuous 8-bit
0x, 10
1
40 ADCK cycles + 5 bus clock cycles
Single or first continuous 10-bit
0x, 10
1
43 ADCK cycles + 5 bus clock cycles
Single or first continuous 8-bit
11
0
5 μs + 20 ADCK + 5 bus clock cycles
Single or first continuous 10-bit
11
0
5 μs + 23 ADCK + 5 bus clock cycles
Single or first continuous 8-bit
11
1
5 μs + 40 ADCK + 5 bus clock cycles
Single or first continuous 10-bit
11
1
5 μs + 43 ADCK + 5 bus clock cycles
Subsequent continuous 8-bit;
fBUS > fADCK
xx
0
17 ADCK cycles
Subsequent continuous 10-bit;
fBUS > fADCK
xx
0
20 ADCK cycles
Subsequent continuous 8-bit;
fBUS > fADCK/11
xx
1
37 ADCK cycles
Subsequent continuous 10-bit;
fBUS > fADCK/11
xx
1
40 ADCK cycles
The maximum total conversion time is determined by the clock source chosen and the divide ratio selected.
The clock source is selectable by the ADICLK bits, and the divide ratio is specified by the ADIV bits. For
example, in 10-bit mode, with the bus clock selected as the input clock source, the input clock divide-by-1
ratio selected, and a bus frequency of 8 MHz, then the conversion time for a single conversion is:
Conversion time =
23 ADCK cyc
8 MHz/1
+
5 bus cyc
8 MHz
= 3.5 μs
Number of bus cycles = 3.5 μs x 8 MHz = 28 cycles
NOTE
The ADCK frequency must be between fADCK minimum and fADCK
maximum to meet ADC specifications.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
113
Analog-to-Digital Converter (S08ADC10V1)
8.4.5
Automatic Compare Function
The compare function can be configured to check for either an upper limit or lower limit. After the input
is sampled and converted, the result is added to the two’s complement of the compare value (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 be used to monitor the voltage on a channel while
the MCU is in either wait or stop3 mode. The ADC interrupt will wake the
MCU when the compare condition is met.
8.4.6
MCU Wait Mode Operation
The WAIT instruction puts the MCU in a lower power-consumption standby mode from which recovery
is very fast because the clock sources remain active. If a conversion is in progress when the MCU enters
wait mode, it continues until completion. Conversions can be initiated while the MCU is in wait mode by
means of the hardware trigger or if continuous conversions are enabled.
The bus clock, bus clock divided by two, and ADACK are available as conversion clock sources while in
wait mode. The use of ALTCLK as the conversion clock source in wait is dependent on the definition of
ALTCLK for this MCU. Consult the module introduction for information on ALTCLK specific to this
MCU.
A conversion complete event sets the COCO and generates an ADC interrupt to wake the MCU from wait
mode if the ADC interrupt is enabled (AIEN = 1).
8.4.7
MCU Stop3 Mode Operation
The STOP instruction is used to put the MCU in a low power-consumption standby mode during which
most or all clock sources on the MCU are disabled.
8.4.7.1
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
are unaffected by stop3 mode.After exiting from stop3 mode, a software or hardware trigger is required to
resume conversions.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
114
Freescale Semiconductor
Analog-to-Digital Converter (S08ADC10V1)
8.4.7.2
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
It is possible for the ADC module to wake the system from low power stop
and cause the MCU to begin consuming run-level currents without
generating a system level interrupt. To prevent this scenario, software must
ensure that the data transfer blocking mechanism (discussed in
Section 8.4.4.2, “Completing Conversions,”) is cleared when entering stop3
and continuing ADC conversions.
8.4.8
MCU Stop1 and Stop2 Mode Operation
The ADC module is automatically disabled when the MCU enters either stop1 or stop2 mode. All module
registers contain their reset values following exit from stop1 or stop2. Therefore the module must be
re-enabled and re-configured following exit from stop1 or stop2.
8.5
Initialization Information
This section gives an example which provides some basic direction on how a user would initialize and
configure the ADC module. The user has the flexibility of choosing between configuring the module for
8-bit or 10-bit resolution, single or continuous conversion, and a polled or interrupt approach, among many
other options. Refer to Table 8-6, Table 8-7, and Table 8-8 for information used in this example.
NOTE
Hexadecimal values designated by a preceding 0x, binary values designated
by a preceding %, and decimal values have no preceding character.
8.5.1
8.5.1.1
ADC Module Initialization Example
Initialization Sequence
Before the ADC module can be used to complete conversions, an initialization procedure must be
performed. A typical sequence is as follows:
1. Update the configuration register (ADCCFG) to select the input clock source and the divide ratio
used to generate the internal clock, ADCK. This register is also used for selecting sample time and
low-power configuration.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
115
Analog-to-Digital Converter (S08ADC10V1)
2. Update status and control register 2 (ADCSC2) to select the conversion trigger (hardware or
software) and compare function options, if enabled.
3. Update status and control register 1 (ADCSC1) to select whether conversions will be continuous
or completed only once, and to enable or disable conversion complete interrupts. The input channel
on which conversions will be performed is also selected here.
8.5.1.2
Pseudo — Code Example
In this example, the ADC module will be set up with interrupts enabled to perform a single 10-bit
conversion at low power with a long sample time on input channel 1, where the internal ADCK clock will
be derived from the bus clock divided by 1.
ADCCFG = 0x98 (%10011000)
Bit 7
ADLPC
1
Configures for low power (lowers maximum clock speed)
Bit 6:5 ADIV
00
Sets the ADCK to the input clock ÷ 1
Bit 4
ADLSMP 1
Configures for long sample time
Bit 3:2 MODE
10
Sets mode at 10-bit conversions
Bit 1:0 ADICLK 00
Selects bus clock as input clock source
ADCSC2 = 0x00 (%00000000)
Bit 7
ADACT
0
Bit 6
ADTRG
0
Bit 5
ACFE
0
Bit 4
ACFGT
0
Bit 3:2
00
Bit 1:0
00
Flag indicates if a conversion is in progress
Software trigger selected
Compare function disabled
Not used in this example
Unimplemented or reserved, always reads zero
Reserved for Freescale’s internal use; always write zero
ADCSC1 = 0x41 (%01000001)
Bit 7
COCO
0
Bit 6
AIEN
1
Bit 5
ADCO
0
Bit 4:0 ADCH
00001
Read-only flag which is set when a conversion completes
Conversion complete interrupt enabled
One conversion only (continuous conversions disabled)
Input channel 1 selected as ADC input channel
ADCRH/L = 0xxx
Holds results of conversion. Read high byte (ADCRH) before low byte (ADCRL) so that conversion
data cannot be overwritten with data from the next conversion.
ADCCVH/L = 0xxx
Holds compare value when compare function enabled
APCTL1=0x02
AD1 pin I/O control disabled. All other AD pins remain general purpose I/O pins
APCTL2=0x00
All other AD pins remain general purpose I/O pins
MC9S08QD4 Series MCU Data Sheet, Rev. 3
116
Freescale Semiconductor
Analog-to-Digital Converter (S08ADC10V1)
RESET
INITIALIZE ADC
ADCCFG = $98
ADCSC2 = $00
ADCSC1 = $41
CHECK
COCO=1?
NO
YES
READ ADCRH
THEN ADCRL TO
CLEAR COCO BIT
CONTINUE
Figure 8-14. Initialization Flowchart for Example
8.6
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.
8.6.1
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.
8.6.1.1
Analog Supply Pins
The ADC module has analog power and ground supplies (VDDAD and VSSAD) which are available as
separate pins on some devices. On other devices, VSSAD is shared on the same pin as the MCU digital VSS,
and on others, both VSSAD and VDDAD are shared with the MCU digital supply pins. In these cases, there
are separate pads for the analog supplies which are bonded to the same pin as the corresponding digital
supply so that some degree of isolation between the supplies is maintained.
When available on a separate pin, both VDDAD and VSSAD must be connected to the same voltage potential
as their corresponding MCU digital supply (VDD and VSS) and must be routed carefully for maximum
noise immunity and bypass capacitors placed as near as possible to the package.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
117
Analog-to-Digital Converter (S08ADC10V1)
In cases where separate power supplies are used for analog and digital power, the ground connection
between these supplies must be at the VSSAD pin. This must be the only ground connection between these
supplies if possible. The VSSAD pin makes a good single point ground location.
8.6.1.2
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 that is between the minimum VDDAD spec and the VDDAD potential (VREFH
must never exceed VDDAD). When available on a separate pin, VREFL must be connected to the same
voltage potential as VSSAD. Both VREFH and VREFL must be routed carefully for maximum noise
immunity and bypass capacitors placed as near as possible to the package.
AC current in the form of current spikes required to supply charge to the capacitor array at each successive
approximation step is drawn through the VREFH and VREFL loop. The best external component to meet this
current demand is a 0.1 μF capacitor with good high frequency characteristics. This capacitor is connected
between VREFH and VREFL and must be placed as near as possible to the package pins. Resistance in the
path is not recommended because the current will cause a voltage drop which could result in conversion
errors. Inductance in this path must be minimum (parasitic only).
8.6.1.3
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 will be in its high impedance state and the pullup is disabled. Also, the input
buffer draws dc current when its input is not at either VDD or VSS. Setting the pin control register bits for
all pins used as analog inputs 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 $3FF (full scale 10-bit representation) or $FF
(full scale 8-bit representation). If the input is equal to or less than VREFL, the converter circuit converts it
to $000. Input voltages between VREFH and VREFL are straight-line linear conversions. There will be a
brief current associated with VREFL when the sampling capacitor is charging. The input is sampled for
3.5 cycles of the ADCK source when ADLSMP is low, or 23.5 cycles when ADLSMP is high.
For minimal loss of accuracy due to current injection, pins adjacent to the analog input pins must not be
transitioning during conversions.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
118
Freescale Semiconductor
Analog-to-Digital Converter (S08ADC10V1)
8.6.2
Sources of Error
Several sources of error exist for A/D conversions. These are discussed in the following sections.
8.6.2.1
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 10-bit resolution) can be achieved within the minimum sample window (3.5 cycles @
8 MHz maximum ADCK frequency) provided the resistance of the external analog source (RAS) is kept
below 5 kΩ.
Higher source resistances or higher-accuracy sampling is possible by setting ADLSMP (to increase the
sample window to 23.5 cycles) or decreasing ADCK frequency to increase sample time.
8.6.2.2
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 mode or 10 in 10-bit mode).
8.6.2.3
Noise-Induced Errors
System noise which occurs during the sample or conversion process can affect the accuracy of the
conversion. The ADC accuracy numbers are guaranteed as specified only if the following conditions are
met:
• There is a 0.1 μF low-ESR capacitor from VREFH to VREFL.
• There is a 0.1 μF low-ESR capacitor from VDDAD to VSSAD.
• If inductive isolation is used from the primary supply, an additional 1 μF capacitor is placed from
VDDAD to VSSAD.
• VSSAD (and VREFL, if connected) is connected to VSS at a quiet point in the ground plane.
• Operate the MCU in wait or stop3 mode before initiating (hardware triggered conversions) or
immediately after initiating (hardware or software triggered conversions) the ADC conversion.
— For software triggered conversions, immediately follow the write to the 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.
• There is no I/O switching, input or output, on the MCU during the conversion.
There are some situations where external system activity causes radiated or conducted noise emissions or
excessive VDD noise is coupled into the ADC. In these situations, or when the MCU cannot be placed in
wait or stop3 or I/O activity cannot be halted, these recommended actions may reduce the effect of noise
on the accuracy:
• Place a 0.01 μF capacitor (CAS) on the selected input channel to VREFL or VSSAD (this will
improve noise issues but will affect sample rate based on the external analog source resistance).
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
119
Analog-to-Digital Converter (S08ADC10V1)
•
•
Average the result by converting the analog input many times in succession and dividing the sum
of the results. Four samples are required to eliminate the effect of a 1LSB, one-time error.
Reduce the effect of synchronous noise by operating off the asynchronous clock (ADACK) and
averaging. Noise that is synchronous to ADCK cannot be averaged out.
8.6.2.4
Code Width and Quantization Error
The ADC quantizes the ideal straight-line transfer function into 1024 steps (in 10-bit mode). Each step
ideally has the same height (1 code) and width. The width is defined as the delta between the transition
points to one code and the next. The ideal code width for an N bit converter (in this case N can be 8 or 10),
defined as 1LSB, is:
1LSB = (VREFH - VREFL) / 2N
Eqn. 8-2
There is an inherent quantization error due to the digitization of the result. For 8-bit or 10-bit conversions
the code will transition when the voltage is at the midpoint between the points where the straight line
transfer function is exactly represented by the actual transfer function. Therefore, the quantization error
will be ± 1/2LSB in 8- or 10-bit mode. As a consequence, however, the code width of the first ($000)
conversion is only 1/2LSB and the code width of the last ($FF or $3FF) is 1.5LSB.
8.6.2.5
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 (1/2LSB). Note, if the first
conversion is $001, then the difference between the actual $001 code width and its ideal (1LSB) is
used.
• Full-scale error (EFS) — This error is defined as the difference between the actual code width of
the last conversion and the ideal code width (1.5LSB). Note, if the last conversion is $3FE, then the
difference between the actual $3FE code width and its ideal (1LSB) is used.
• Differential non-linearity (DNL) — This error is defined as the worst-case difference between the
actual code width and the ideal code width for all conversions.
• Integral non-linearity (INL) — This error is defined as the highest-value the (absolute value of the)
running sum of DNL achieves. More simply, this is the worst-case difference of the actual
transition voltage to a given code and its corresponding ideal transition voltage, for all codes.
• Total unadjusted error (TUE) — This error is defined as the difference between the actual transfer
function and the ideal straight-line transfer function, and therefore includes all forms of error.
8.6.2.6
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
MC9S08QD4 Series MCU Data Sheet, Rev. 3
120
Freescale Semiconductor
Analog-to-Digital Converter (S08ADC10V1)
converter yields the lower code (and vice-versa). However, even very small amounts of system noise can
cause the converter to be indeterminate (between two codes) for a range of input voltages around the
transition voltage. This range is normally around ±1/2 LSB and will increase with noise. This error may be
reduced by repeatedly sampling the input and averaging the result. Additionally the techniques discussed
in Section 8.6.2.3, “Noise-Induced Errors,” will reduce this error.
Non-monotonicity is defined as when, except for code jitter, the converter converts to a lower code for a
higher input voltage. Missing codes are those values which are never converted for any input value.
In 8-bit or 10-bit mode, the ADC is guaranteed to be monotonic and to have no missing codes.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
121
Analog-to-Digital Converter (S08ADC10V1)
MC9S08QD4 Series MCU Data Sheet, Rev. 3
122
Freescale Semiconductor
Chapter 9
Internal Clock Source (S08ICSV1)
9.1
Introduction
The internal clock source (ICS) module provides clock source choices for the MCU. The module contains
a frequency-locked loop (FLL) as a clock source that is controllable by an internal reference clock. The
module can provide this FLL clock or the internal reference clock as a source for the MCU system clock,
ICSOUT.
Whichever clock source is chosen, ICSOUT is passed through a bus clock divider (BDIV) which allows a
lower final output clock frequency to be derived. ICSOUT is two times the bus frequency.
Figure 9-1 Shows the MC9S08QD4 series with the ICS module highlighted.
9.1.1
ICS Configuration Information
Bit-1 and bit-2 of ICS control register 1 (ICSC1) always read as 1.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
123
Chapter 9 Internal Clock Source (S08ICSV1)
BKGD/MS
IRQ
HCS08 CORE
BDC
HCS08 SYSTEM CONTROL
RESETS AND INTERRUPTS
MODES OF OPERATION
POWER MANAGEMENT
RTI
COP
IRQ
LVD
USER FLASH
4096 / 2048 BYTES
4-BIT KEYBOARD
INTERRUPT MODULE (KBI)
4
TPM2CH0
1-CH 16-BIT TIMER/PWM
MODULE (TPM2)
TCLK2
2-CH 16-BIT TIMER/PWM
MODULE (TPM1)
TPM1CH0
TPM1CH1
TCLK1
10-BIT
ANALOG-TO-DIGITAL
CONVERTER (ADC)
PORT A
CPU
PTA5/TPM2CH0I/IRQ/RESET
PTA4/TPM2CH0O/BKGD/MS
PTA3/KBI1P3/TCLK2/ADC1P3
PTA2/KBI1P2/TCLK1/ADC1P2
PTA1/KBI1P1/TPM1CH1/ADC1P1
PTA0/KBI1P0/TPM1CH0/ADC1P0
4
USER RAM
256 / 128 BYTES
16 MHz INTERNAL CLOCK
SOURCE (ICS)
VSS
VDD
VOLTAGE REGULATOR
VDDA
VSSA
VREFH
VREFL
NOTES:
1 Port pins are software configurable with pullup device if input port.
2 Port pins are software configurable for output drive strength.
3
Port pins are software configurable for output slew rate control.
4 IRQ contains a software configurable (IRQPDD) pullup/pulldown device if PTA5 enabled as IRQ pin function (IRQPE = 1).
5 RESET contains integrated pullup device if PTA5 enabled as reset pin function (RSTPE = 1).
6
PTA5 does not contain a clamp diode to VDD and must not be driven above VDD. The voltage measured on this pin when
internal pullup is enabled may be as low as VDD – 0.7 V. The internal gates connected to this pin are pulled to VDD.
7
PTA4 contains integrated pullup device if BKGD enabled (BKGDPE = 1).
8 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.
Figure 9-1. MC9S08QD4 Series Block Diagram Highlighting ICS Block
MC9S08QD4 Series MCU Data Sheet, Rev. 3
124
Freescale Semiconductor
Internal Clock Source (S08ICSV1)
9.1.2
Features
Key features of the ICS module are:
• Frequency-locked loop (FLL) is trimmable for accuracy
— 0.2% resolution using internal 32 kHz reference
— 2% deviation over voltage and temperature using internal 32 kHz reference
• Internal or external reference clocks up to 5 MHz can be used to control the FLL
— 3 bit select for reference divider is provided
• Internal reference clock has 9 trim bits available
• Internal or external reference clocks can be selected as the clock source for the MCU
• Whichever clock is selected as the source can be divided down
— 2 bit select for clock divider is provided
– Allowable dividers are: 1, 2, 4, 8
– BDC clock is provided as a constant divide by 2 of the DCO output
• Control signals for a low power oscillator as the external reference clock are provided
— HGO, RANGE, EREFS, ERCLKEN, EREFSTEN
• FLL engaged internal mode is automatically selected out of reset
9.1.3
Modes of Operation
There are seven modes of operation for the ICS: FEI, FEE, FBI, FBILP, FBE, FBELP, and stop.
9.1.3.1
FLL Engaged Internal (FEI)
In FLL engaged internal mode, which is the default mode, the ICS supplies a clock derived from the FLL
which is controlled by the internal reference clock. The BDC clock is supplied from the FLL.
9.1.3.2
FLL Engaged External (FEE)
In FLL engaged external mode, the ICS supplies a clock derived from the FLL which is controlled by an
external reference clock. The BDC clock is supplied from the FLL.
9.1.3.3
FLL Bypassed Internal (FBI)
In FLL bypassed internal mode, the FLL is enabled and controlled by the internal reference clock, but is
bypassed. The ICS supplies a clock derived from the internal reference clock. The BDC clock is supplied
from the FLL.
9.1.3.4
FLL Bypassed Internal Low Power (FBILP)
In FLL bypassed internal low power mode, the FLL is disabled and bypassed, and the ICS supplies a clock
derived from the internal reference clock. The BDC clock is not available.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
125
Internal Clock Source (S08ICSV1)
9.1.3.5
FLL Bypassed External (FBE)
In FLL bypassed external mode, the FLL is enabled and controlled by an external reference clock, but is
bypassed. The ICS supplies a clock derived from the external reference clock. The external reference clock
can be an external crystal/resonator supplied by an OSC controlled by the ICS, or it can be another external
clock source. The BDC clock is supplied from the FLL.
9.1.3.6
FLL Bypassed External Low Power (FBELP)
In FLL bypassed external low power mode, the FLL is disabled and bypassed, and the ICS supplies a clock
derived from the external reference clock. The external reference clock can be an external crystal/resonator
supplied by an OSC controlled by the ICS, or it can be another external clock source. The BDC clock is
not available.
9.1.3.7
Stop (STOP)
In stop mode the FLL is disabled and the internal or external reference clocks can be selected to be enabled
or disabled. The BDC clock is not available and the ICS does not provide an MCU clock source.
9.1.4
Block Diagram
Figure 9-2 is the ICS block diagram.
Optional
External Reference
Clock Source
Block
RANGE
HGO
EREFS
EREFSTEN
ICSERCLK
ERCLKEN
IRCLKEN
IREFSTEN
ICSIRCLK
CLKS
BDIV
/ 2n
Internal
Reference
Clock
9
IREFS
ICSOUT
n=0-3
LP
DCO
DCOOUT
/2
ICSLCLK
TRIM
ICSFFCLK
9
/ 2n
RDIV_CLK
Filter
n=0-7
FLL
RDIV
Internal Clock Source Block
Figure 9-2. Internal Clock Source (ICS) Block Diagram
MC9S08QD4 Series MCU Data Sheet, Rev. 3
126
Freescale Semiconductor
Internal Clock Source (S08ICSV1)
9.2
External Signal Description
There are no ICS signals that connect off chip.
9.3
Register Definition
9.3.1
ICS Control Register 1 (ICSC1)
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 9-3. ICS Control Register 1 (ICSC1)
Table 9-1. ICS Control Register 1 Field Descriptions
Field
Description
7:6
CLKS
Clock Source Select — Selects the clock source that controls the bus frequency. The actual bus frequency
depends on the value of the BDIV bits.
00 Output of FLL is selected.
01 Internal reference clock is selected.
10 External reference clock is selected.
11 Reserved, defaults to 00.
5:3
RDIV
Reference Divider — Selects the amount to divide down the FLL reference clock selected by the IREFS bits.
Resulting frequency must be in the range 31.25 kHz to 39.0625 kHz.
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 — The IREFS bit selects the reference clock source for the FLL.
1 Internal reference clock selected
0 External reference clock selected
1
IRCLKEN
0
IREFSTEN
Internal Reference Clock Enable — The IRCLKEN bit enables the internal reference clock for use as
ICSIRCLK.
1 ICSIRCLK active
0 ICSIRCLK inactive
Internal Reference Stop Enable — The IREFSTEN bit controls whether or not the internal reference clock
remains enabled when the ICS enters stop mode.
1 Internal reference clock stays enabled in stop if IRCLKEN is set or if ICS is in FEI, FBI, or FBILP mode before
entering stop
0 Internal reference clock is disabled in stop
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
127
Internal Clock Source (S08ICSV1)
9.3.2
ICS Control Register 2 (ICSC2)
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 9-4. ICS Control Register 2 (ICSC2)
Table 9-2. ICS 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. 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.
1 High frequency range selected for the external oscillator
0 Low frequency range selected for the external oscillator
4
HGO
High Gain Oscillator Select — The HGO bit controls the external oscillator mode of operation.
1 Configure external oscillator for high gain operation
0 Configure external oscillator for low power operation
3
LP
Low Power Select — The LP bit controls whether the FLL is disabled in FLL bypassed modes.
1 FLL is disabled in bypass modes unless BDM is active
0 FLL is not disabled in bypass mode
2
EREFS
1
ERCLKEN
External Reference Select — The EREFS bit selects the source for the external reference clock.
1 Oscillator requested
0 External Clock Source requested
External Reference Enable — The ERCLKEN bit enables the external reference clock for use as ICSERCLK.
1 ICSERCLK active
0 ICSERCLK inactive
0
External Reference Stop Enable — The EREFSTEN bit controls whether or not the external reference clock
EREFSTEN remains enabled when the ICS enters stop mode.
1 External reference clock stays enabled in stop if ERCLKEN is set or if ICS is in FEE, FBE, or FBELP mode
before entering stop
0 External reference clock is disabled in stop
MC9S08QD4 Series MCU Data Sheet, Rev. 3
128
Freescale Semiconductor
Internal Clock Source (S08ICSV1)
9.3.3
ICS Trim Register (ICSTRM)
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 9-5. ICS Trim Register (ICSTRM)
Table 9-3. ICS Trim Register Field Descriptions
Field
Description
7:0
TRIM
ICS Trim Setting — The TRIM bits control the internal reference clock frequency by controlling the internal
reference clock period. The bits’ effect 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 ICSSC as the FTRIM bit.
9.3.4
ICS Status and Control (ICSSC)
R
7
6
5
4
0
0
0
0
3
2
CLKST
1
0
OSCINIT
FTRIM
W
POR:
Reset:
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
U
Figure 9-6. ICS Status and Control Register (ICSSC)
Table 9-4. ICS Status and Control Register Field Descriptions
Field
7:4
3:2
CLKST
Description
Reserved, must be cleared.
Clock Mode Status — The CLKST bits indicate the current clock mode. The CLKST bits don’t update
immediately after a write to the CLKS bits due to internal synchronization between clock domains.
00 Output of FLL is selected.
01 FLL Bypassed, Internal reference clock is selected.
10 FLL Bypassed, External reference clock is selected.
11 Reserved.
1
OSC Initialization — If the external reference clock is selected by ERCLKEN or by the ICS being in FEE, FBE,
or FBELP 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 cleared only when either ERCLKEN or EREFS are cleared.
0
ICS Fine Trim — The FTRIM bit 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.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
129
Internal Clock Source (S08ICSV1)
9.4
Functional Description
9.4.1
Operational Modes
IREFS=1
CLKS=00
FLL Engaged
Internal (FEI)
IREFS=0
CLKS=10
BDM Enabled
or LP =0
FLL Bypassed
External Low
Power(FBELP)
FLL Bypassed
External (FBE)
IREFS=0
CLKS=10
BDM Disabled
and LP=1
IREFS=1
CLKS=01
BDM Enabled
or LP=0
FLL Bypassed
Internal (FBI)
FLL Bypassed
Internal Low
Power(FBILP)
IREFS=1
CLKS=01
BDM Disabled
and LP=1
FLL Engaged
External (FEE)
IREFS=0
CLKS=00
Entered from any state
when MCU enters stop
Stop
Returns to state that was active
before MCU entered stop, unless
reset occurs while in stop.
Figure 9-7. Clock Switching Modes
The seven states of the ICS are shown as a state diagram and are described below. The arrows indicate the
allowed movements between the states.
9.4.1.1
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
• RDIV bits are written to divide trimmed reference clock to be within the range of 31.25 kHz to
39.0625 kHz.
In FLL engaged internal mode, the ICSOUT clock is derived from the FLL clock, which is controlled by
the internal reference clock. The FLL loop will lock the frequency to 512 times the filter frequency, as
selected by the RDIV bits. The ICSLCLK is available for BDC communications, and the internal reference
clock is enabled.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
130
Freescale Semiconductor
Internal Clock Source (S08ICSV1)
9.4.1.2
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
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 ICSOUT clock is derived from the FLL clock which is controlled by
the external reference clock.The FLL loop will lock the frequency to 512 times the filter frequency, as
selected by the RDIV bits. The ICSLCLK is available for BDC communications, and the external
reference clock is enabled.
9.4.1.3
FLL Bypassed Internal (FBI)
The FLL bypassed internal (FBI) mode is entered when all the following conditions occur:
• CLKS bits are written to 01
• IREFS bit is written to 1.
• BDM mode is active or LP bit is written to 0
In FLL bypassed internal mode, the ICSOUT clock is derived from the internal reference clock. The FLL
clock is controlled by the internal reference clock, and the FLL loop will lock the FLL frequency to 512
times the Filter frequency, as selected by the RDIV bits. The ICSLCLK will be available for BDC
communications, and the internal reference clock is enabled.
9.4.1.4
FLL Bypassed Internal Low Power (FBILP)
The FLL bypassed internal low power (FBILP) mode is entered when all the following conditions occur:
• CLKS bits are written to 01
• IREFS bit is written to 1.
• BDM mode is not active and LP bit is written to 1
In FLL bypassed internal low power mode, the ICSOUT clock is derived from the internal reference clock
and the FLL is disabled. The ICSLCLK will be not be available for BDC communications, and the internal
reference clock is enabled.
9.4.1.5
FLL Bypassed External (FBE)
The FLL bypassed external (FBE) mode is entered when all the following conditions occur:
• CLKS bits are written to 10.
• IREFS bit is written to 0.
• BDM mode is active or LP bit is written to 0.
In FLL bypassed external mode, the ICSOUT clock is derived from the external reference clock. The FLL
clock is controlled by the external reference clock, and the FLL loop will lock the FLL frequency to 512
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
131
Internal Clock Source (S08ICSV1)
times the filter frequency, as selected by the RDIV bits, so that the ICSLCLK will be available for BDC
communications, and the external reference clock is enabled.
9.4.1.6
FLL Bypassed External Low Power (FBELP)
The FLL bypassed external low power (FBELP) mode is entered when all the following conditions occur:
• CLKS bits are written to 10.
• IREFS bit is written to 0.
• BDM mode is not active and LP bit is written to 1.
In FLL bypassed external low power mode, the ICSOUT clock is derived from the external reference clock
and the FLL is disabled. The ICSLCLK will be not be available for BDC communications. The external
reference clock is enabled.
9.4.1.7
Stop
Stop mode is entered whenever the MCU enters a STOP state. In this mode, all ICS clock signals are static
except in the following cases:
ICSIRCLK will be active in stop mode when all the following conditions occur:
• IRCLKEN bit is written to 1
• IREFSTEN bit is written to 1
ICSERCLK will be active in stop mode when all the following conditions occur:
• ERCLKEN bit is written to 1
• EREFSTEN bit is written to 1
9.4.2
Mode Switching
When switching between FLL engaged internal (FEI) and FLL engaged external (FEE) modes the IREFS
bit can be changed at anytime, but the RDIV bits must be changed simultaneously so that the resulting
frequency stays in the range of 31.25 kHz to 39.0625 kHz. After a change in the IREFS value the FLL will
begin locking again after a few full cycles of the resulting divided reference frequency.
The CLKS bits can also be changed at anytime, but the RDIV bits must be changed simultaneously so that
the resulting frequency stays in the range of 31.25 kHz to 39.0625 kHz. The actual switch to the newly
selected clock will not occur until after a few full cycles of the new clock. If the newly selected clock is
not available, the previous clock will remain selected.
9.4.3
Bus Frequency Divider
The BDIV bits can be changed at anytime and the actual switch to the new frequency will occur
immediately.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
132
Freescale Semiconductor
Internal Clock Source (S08ICSV1)
9.4.4
Low Power Bit Usage
The low power bit (LP) is provided to allow the FLL to be disabled and thus conserve power when it is
not being used. However, in some applications it may be desirable to enable the FLL and allow it to lock
for maximum accuracy before switching to an FLL engaged mode. Do this by writing the LP bit to 0.
9.4.5
Internal Reference Clock
When IRCLKEN is set the internal reference clock signal will be presented as ICSIRCLK, which can be
used as an additional clock source. The ICSIRCLK 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 ICSTRM
register. Writing a larger value will slow down the ICSIRCLK frequency, and writing a smaller value to
the ICSTRM register will speed up the ICSIRCLK frequency. The TRIM bits will effect the ICSOUT
frequency if the ICS is in FLL engaged internal (FEI), FLL bypassed internal (FBI), or FLL bypassed
internal low power (FBILP) mode. The TRIM and FTRIM value will not be affected by a reset.
Until ICSIRCLK is trimmed, programming low reference divider (RDIV) factors may result in ICSOUT
frequencies that exceed the maximum chip-level frequency and violate the chip-level clock timing
specifications (see the Device Overview chapter).
If IREFSTEN is set and the IRCLKEN bit is written to 1, the internal reference clock will keep running
during stop mode in order to provide a fast recovery upon exiting stop.
All MCU devices are factory programmed with a trim value in a reserved memory location. This value can
be copied to the ICSTRM register during reset initialization. The factory trim value does not include the
FTRIM bit. For finer precision, the user can trim the internal oscillator in the application and set the
FTRIM bit accordingly.
9.4.6
Optional External Reference Clock
The ICS module can support an external reference clock with frequencies between 31.25 kHz to 5 MHz
in all modes. When the ERCLKEN is set, the external reference clock signal will be presented as
ICSERCLK, which can be used as an additional clock source. When IREFS = 1, the external reference
clock will not be used by the FLL and will only be used as ICSERCLK. 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 is set and the ERCLKEN bit is written to 1, the external reference clock will keep running
during stop mode in order to provide a fast recovery upon exiting stop.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
133
Internal Clock Source (S08ICSV1)
9.4.7
Fixed Frequency Clock
The ICS presents the divided FLL reference clock as ICSFFCLK for use as an additional clock source for
peripheral modules. The ICS provides an output signal (ICSFFE) which indicates when the ICS is
providing ICSOUT frequencies four times or greater than the divided FLL reference clock (ICSFFCLK).
In FLL engaged mode (FEI and FEE) this is always true and ICSFFE is always high. In ICS bypass modes,
ICSFFE will get asserted for the following combinations of BDIV and RDIV values:
• BDIV=00 (divide by 1), RDIV ≥ 010
• BDIV=01 (divide by 2), RDIV ≥ 011
• BDIV=10 (divide by 4), RDIV ≥ 100
• BDIV=11 (divide by 8), RDIV ≥ 101
9.5
Module Initialization
This section describes how to initialize and configure the ICS module. The following sections contain two
initialization examples.
9.5.1
ICS Module Initialization Sequence
The ICS comes out of POR configured for FEI mode with the BDIV set for divide-by 2. The internal
reference will stabilize in tIRST microseconds before the FLL can acquire lock. As soon as the internal
reference is stable, the FLL will acquire lock in tAcquire 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 ICSSC register,
and 0xFFAF for storing the 8-bit trim value for the ICSTRM 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.
9.5.1.1
Initialization Sequence, Internal Clock Mode to External Clock Mode
To change from FEI or FBI clock modes to FEE or FBE clock modes, follow this procedure:
1. Enable the external clock source by setting the appropriate bits in ICSC2.
— If FBE will be the selected mode, also set the LP bit at this time to minimize power
consumption.
2. If necessary, wait for the external clock source to stabilize. Typical crystal startup times are given
in Electrical Characteristics appendix. If EREFS is set in step 1, then the OSCINIT bit will set as
soon as the oscillator has completed the initialization cycles.
3. Write to ICSC1 to select the clock mode.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
134
Freescale Semiconductor
Internal Clock Source (S08ICSV1)
— If entering FEE, set the reference divider and clear the IREFS bit to switch to the external
reference.
— 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 clock and external clock
modes. For minimum power consumption, leave the internal reference disabled while in an
external clock mode.
4. The CLKST bits can be monitored to determine when the mode switch has completed. If FEE was
selected, the bus clock will be stable in tAcquire milliseconds. The CLKST bits will not change when
switching from FEI to FEE.
9.5.1.2
Initialization Sequence, External Clock Mode to Internal Clock Mode
To change from FEE or FBE clock modes to FEI or FBI clock modes, follow this procedure:
1. If saved, copy the TRIM and FTRIM values from FLASH to the ICSTRM and ICSSC registers.
This needs to be done only once after POR.
2. Enable the internal clock reference by selecting FBI (CLKS = 0:1) or selecting FEI (CLKS = 0:0,
RDIV = 0:0:0, and IREFS = 1) in ICSC1.
3. Wait for the internal clock reference to stabilize. The typical startup time is given in the Electrical
Characteristics appendix.
4. Write to ICSC2 to disable the external clock.
— The external reference can optionally be kept running by setting the ERCLKEN bit. This is
useful if the application will switch back and forth between internal clock and external clock
modes. For minimum power consumption, leave the external reference disabled while in an
internal clock mode.
— If FBI will be the selected mode, also set the LP bit at this time to minimize power
consumption.
NOTE
The internal reference must be enabled and running before disabling the
external clock. Therefore it is imperative to execute steps 2 and 3 before
step 4.
5. The CLKST bits in the ICSSC register can be monitored to determine when the mode switch has
completed. The CLKST bits will not change when switching from FEE to FEI. If FEI was selected,
the bus clock will be stable in tAcquire milliseconds.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
135
Internal Clock Source (S08ICSV1)
MC9S08QD4 Series MCU Data Sheet, Rev. 3
136
Freescale Semiconductor
Chapter 10
Keyboard Interrupt (S08KBIV2)
10.1
Introduction
The keyboard interrupt KBI module provides up to eight independently enabled external interrupt sources.
Only four (KBI1P0–KBI1P3) of the possible interrupts are implemented on the MC9S08QD4 series MCU.
These inputs are selected by the KBIPE bits.
Figure 10-1 Shows the MC9S08QD4 series with the KBI module and pins highlighted.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
137
Chapter 10 Keyboard Interrupt (S08KBIV2)
BKGD/MS
IRQ
HCS08 CORE
BDC
HCS08 SYSTEM CONTROL
RESETS AND INTERRUPTS
MODES OF OPERATION
POWER MANAGEMENT
RTI
COP
IRQ
LVD
USER FLASH
4096 / 2048 BYTES
4-BIT KEYBOARD
INTERRUPT MODULE (KBI)
4
TPM2CH0
1-CH 16-BIT TIMER/PWM
MODULE (TPM2)
TCLK2
2-CH 16-BIT TIMER/PWM
MODULE (TPM1)
TPM1CH0
TPM1CH1
TCLK1
10-BIT
ANALOG-TO-DIGITAL
CONVERTER (ADC)
PORT A
CPU
PTA5/TPM2CH0I/IRQ/RESET
PTA4/TPM2CH0O/BKGD/MS
PTA3/KBI1P3/TCLK2/ADC1P3
PTA2/KBI1P2/TCLK1/ADC1P2
PTA1/KBI1P1/TPM1CH1/ADC1P1
PTA0/KBI1P0/TPM1CH0/ADC1P0
4
USER RAM
256 / 128 BYTES
16 MHz INTERNAL CLOCK
SOURCE (ICS)
VSS
VDD
VOLTAGE REGULATOR
VDDA
VSSA
VREFH
VREFL
NOTES:
1
Port pins are software configurable with pullup device if input port.
2 Port pins are software configurable for output drive strength.
3 Port pins are software configurable for output slew rate control.
4
IRQ contains a software configurable (IRQPDD) pullup/pulldown device if PTA5 enabled as IRQ pin function (IRQPE = 1).
5 RESET contains integrated pullup device if PTA5 enabled as reset pin function (RSTPE = 1).
6 PTA5 does not contain a clamp diode to V
DD and must not be driven above VDD. The voltage measured on this pin when
internal pullup is enabled may be as low as VDD – 0.7 V. The internal gates connected to this pin are pulled to VDD.
7 PTA4 contains integrated pullup device if BKGD enabled (BKGDPE = 1).
8
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.
Figure 10-1. MC9S08QD4 Series Block Diagram Highlighting KBI Block and Pins
MC9S08QD4 Series MCU Data Sheet, Rev. 3
138
Freescale Semiconductor
Keyboard Interrupts (S08KBIV2)
10.1.1
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.
10.1.2
Modes of Operation
This section defines the KBI operation in wait, stop, and background debug modes.
10.1.2.1
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).
10.1.2.2
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.
10.1.2.3
KBI in Active Background Mode
When the microcontroller is in active background mode, the KBI will continue to operate normally.
10.1.3
Block Diagram
The block diagram for the keyboard interrupt module is shown Figure 10-2.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
139
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
INTERRU
PT
KBMOD
KBIPEn
KBIE
KBEDGn
Figure 10-2. KBI Block Diagram
10.2
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 10-1.
Table 10-1. Signal Properties
Signal
Function
KBIPn
10.3
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.
10.3.1
KBI Status and Control Register (KBISC)
KBISC contains the status flag and control bits, which are used to configure the KBI.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
140
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 10-3. KBI Status and Control Register
Table 10-2. 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
10.3.2
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 10-4. KBI Pin Enable Register
Table 10-3. KBIPE Register Field Descriptions
Field
7:0
KBIPEn
10.3.3
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.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
141
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 10-5. KBI Edge Select Register
Table 10-4. KBIES Register Field Descriptions
Field
7:0
KBEDGn
10.4
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).
10.4.1
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.
10.4.2
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
MC9S08QD4 Series MCU Data Sheet, Rev. 3
142
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.
10.4.3
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).
10.4.4
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.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
143
Keyboard Interrupts (S08KBIV2)
MC9S08QD4 Series MCU Data Sheet, Rev. 3
144
Freescale Semiconductor
Chapter 11
Timer/Pulse-Width Modulator (S08TPMV2)
11.1
Introduction
Figure 11-1 shows the MC9S08QD4 series block diagram with the TPM module and pins highlighted.
11.1.1
TPM2 Configuration Information
The TPM2 module consist of a single channel, TPM2CH0, that is multiplexed with input pin PTA4 and
output pin PTA5. When TPM2 is configured for input capture, the TPM2CH0 will connect to the PTA5
(TPM2CH0I). When TPM2 is configured for output compare, the TPM2CH0 will connect to the PTA4
(TPM2CH0O). When TPM2 is disabled, PTA4 and PTA5 function as standard port pins.
11.1.2
TCLK1 and TCLK2 Configuration Information
The TCLK1 and TCLK2 are the external clock source inputs for TPM1 and TPM2 respectively.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
145
Chapter 11 Timer/Pulse-Width Modulator (S08TPMV2)
BKGD/MS
IRQ
HCS08 CORE
BDC
HCS08 SYSTEM CONTROL
RESETS AND INTERRUPTS
MODES OF OPERATION
POWER MANAGEMENT
RTI
COP
IRQ
LVD
USER FLASH
4096 / 2048 BYTES
4-BIT KEYBOARD
INTERRUPT MODULE (KBI)
4
TPM2CH0
1-CH 16-BIT TIMER/PWM
MODULE (TPM2)
TCLK2
2-CH 16-BIT TIMER/PWM
MODULE (TPM1)
TPM1CH0
TPM1CH1
TCLK1
10-BIT
ANALOG-TO-DIGITAL
CONVERTER (ADC)
PORT A
CPU
PTA5/TPM2CH0I/IRQ/RESET
PTA4/TPM2CH0O/BKGD/MS
PTA3/KBI1P3/TCLK2/ADC1P3
PTA2/KBI1P2/TCLK1/ADC1P2
PTA1/KBI1P1/TPM1CH1/ADC1P1
PTA0/KBI1P0/TPM1CH0/ADC1P0
4
USER RAM
256 / 128 BYTES
16 MHz INTERNAL CLOCK
SOURCE (ICS)
VSS
VDD
VOLTAGE REGULATOR
VDDA
VSSA
VREFH
VREFL
NOTES:
1
Port pins are software configurable with pullup device if input port.
2 Port pins are software configurable for output drive strength.
3 Port pins are software configurable for output slew rate control.
4
IRQ contains a software configurable (IRQPDD) pullup/pulldown device if PTA5 enabled as IRQ pin function (IRQPE = 1).
5 RESET contains integrated pullup device if PTA5 enabled as reset pin function (RSTPE = 1).
6 PTA5 does not contain a clamp diode to V
DD and must not be driven above VDD. The voltage measured on this pin when
internal pullup is enabled may be as low as VDD – 0.7 V. The internal gates connected to this pin are pulled to VDD.
7 PTA4 contains integrated pullup device if BKGD enabled (BKGDPE = 1).
8
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.
Figure 11-1. MC9S08QD4 Series Block Diagram Highlighting TPM Block and Pins
MC9S08QD4 Series MCU Data Sheet, Rev. 3
146
Freescale Semiconductor
Timer/Pulse-Width Modulator (S08TPMV2)
11.1.3
Features
The TPM has the following features:
• Each TPM may be configured for buffered, center-aligned pulse-width modulation (CPWM) on all
channels
• Clock sources independently selectable per TPM (multiple TPMs device)
• Selectable clock sources (device dependent): bus clock, fixed system clock, external pin
• Clock prescaler taps for divide by 1, 2, 4, 8, 16, 32, 64, or 128
• 16-bit free-running or up/down (CPWM) count operation
• 16-bit modulus register to control counter range
• Timer system enable
• One interrupt per channel plus a terminal count interrupt for each TPM module (multiple TPMs
device)
• Channel features:
— Each channel may be input capture, output compare, or buffered edge-aligned PWM
— Rising-edge, falling-edge, or any-edge input capture trigger
— Set, clear, or toggle output compare action
— Selectable polarity on PWM outputs
11.1.4
Block Diagram
Figure 11-2 shows the structure of a TPM. Some MCUs include more than one TPM, with various
numbers of channels.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
147
Timer/Pulse-Width Modulator (S08TPMV2)
BUSCLK
XCLK
TPMxCLK
SYNC
CLOCK SOURCE
SELECT
OFF, BUS, XCLK, EXT
CLKSB
PRESCALE AND SELECT
DIVIDE BY
1, 2, 4, 8, 16, 32, 64, or 128
PS2
CLKSA
PS1
PS0
CPWMS
MAIN 16-BIT COUNTER
TOF
COUNTER RESET
INTERRUPT
LOGIC
TOIE
16-BIT COMPARATOR
TPMxMODH:TPMxMO
CHANNEL 0
ELS0B
ELS0A
PORT
LOGIC
16-BIT COMPARATOR
TPMxC0VH:TPMxC0VL
CH0F
INTERRUPT
LOGIC
MS0B
MS0A
ELS1B
ELS1A
CH0IE
TPMxC1VH:TPMxC1VL
CH1F
INTERRUPT
LOGIC
16-BIT LATCH
MS1A
ELSnB
ELSnA
TPMxCHn
PORT
LOGIC
16-BIT COMPARATOR
TPMxCnVH:TPMxCnVL
...
MS1B
CH1IE
...
CHANNEL n
TPMxCH1
PORT
LOGIC
16-BIT COMPARATOR
...
INTERNAL BUS
16-BIT LATCH
CHANNEL 1
TPMxCH0
CHnF
16-BIT LATCH
MSnB
MSnA
CHnIE
INTERRUPT
LOGIC
Figure 11-2. TPM Block Diagram
The central component of the TPM is the 16-bit counter that can operate as a free-running counter, a
modulo counter, or an up-/down-counter when the TPM is configured for center-aligned PWM. The TPM
counter (when operating in normal up-counting mode) provides the timing reference for the input capture,
output compare, and edge-aligned PWM functions. The timer counter modulo registers,
TPMxMODH:TPMxMODL, control the modulo value of the counter. (The values 0x0000 or 0xFFFF
effectively make the counter free running.) Software can read the counter value at any time without
affecting the counting sequence. Any write to either byte of the TPMxCNT counter resets the counter
regardless of the data value written.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
148
Freescale Semiconductor
Timer/Pulse-Width Modulator (S08TPMV2)
All TPM channels are programmable independently as input capture, output compare, or buffered
edge-aligned PWM channels.
11.2
External Signal Description
When any pin associated with the timer is configured as a timer input, a passive pullup can be enabled.
After reset, the TPM modules are disabled and all pins default to general-purpose inputs with the passive
pullups disabled.
11.2.1
External TPM Clock Sources
When control bits CLKSB:CLKSA in the timer status and control register are set to 1:1, the prescaler and
consequently the 16-bit counter for TPMx are driven by an external clock source, TPMxCLK, connected
to an I/O pin. A synchronizer is needed between the external clock and the rest of the TPM. This
synchronizer is clocked by the bus clock so the frequency of the external source must be less than one-half
the frequency of the bus rate clock. The upper frequency limit for this external clock source is specified to
be one-fourth the bus frequency to conservatively accommodate duty cycle and phase-locked loop (PLL)
or frequency-locked loop (FLL) frequency jitter effects.
On some devices the external clock input is shared with one of the TPM channels. When a TPM channel
is shared as the external clock input, the associated TPM channel cannot use the pin. (The channel can still
be used in output compare mode as a software timer.) Also, if one of the TPM channels is used as the
external clock input, the corresponding ELSnB:ELSnA control bits must be set to 0:0 so the channel is not
trying to use the same pin.
11.2.2
TPMxCHn — TPMx Channel n I/O Pins
Each TPM channel is associated with an I/O pin on the MCU. The function of this pin depends on the
configuration of the channel. In some cases, no pin function is needed so the pin reverts to being controlled
by general-purpose I/O controls. When a timer has control of a port pin, the port data and data direction
registers do not affect the related pin(s). See the Pins and Connections chapter for additional information
about shared pin functions.
11.3
Register Definition
The TPM includes:
• An 8-bit status and control register (TPMxSC)
• A 16-bit counter (TPMxCNTH:TPMxCNTL)
• A 16-bit modulo register (TPMxMODH:TPMxMODL)
Each timer channel has:
• An 8-bit status and control register (TPMxCnSC)
• A 16-bit channel value register (TPMxCnVH:TPMxCnVL)
Refer to the direct-page register summary in the Memory chapter of this data sheet for the absolute address
assignments for all TPM registers. This section refers to registers and control bits only by their names. A
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
149
Timer/Pulse-Width Modulator (S08TPMV2)
Freescale-provided equate or header file is used to translate these names into the appropriate absolute
addresses.
11.3.1
Timer Status and Control Register (TPMxSC)
TPMxSC contains the overflow status flag and control bits that are used to configure the interrupt enable,
TPM configuration, clock source, and prescale divisor. These controls relate to all channels within this
timer module.
7
R
6
5
4
3
2
1
0
TOIE
CPWMS
CLKSB
CLKSA
PS2
PS1
PS0
0
0
0
0
0
0
0
TOF
W
Reset
0
= Unimplemented or Reserved
Figure 11-3. Timer Status and Control Register (TPMxSC)
Table 11-1. TPMxSC Register Field Descriptions
Field
Description
7
TOF
Timer Overflow Flag — This flag is set when the TPM counter changes to 0x0000 after reaching the modulo
value programmed in the TPM counter modulo registers. When the TPM is configured for CPWM, TOF is set after
the counter has reached the value in the modulo register, at the transition to the next lower count value. Clear
TOF by reading the TPM status and control register when TOF is set and then writing a 0 to TOF. If another TPM
overflow occurs before the clearing sequence is complete, the sequence is reset so TOF would remain set after
the clear sequence was completed for the earlier TOF. Reset clears TOF. Writing a 1 to TOF has no effect.
0 TPM counter has not reached modulo value or overflow
1 TPM counter has overflowed
6
TOIE
Timer Overflow Interrupt Enable — This read/write bit enables TPM overflow interrupts. If TOIE is set, an
interrupt is generated when TOF equals 1. Reset clears TOIE.
0 TOF interrupts inhibited (use software polling)
1 TOF interrupts enabled
5
CPWMS
Center-Aligned PWM Select — This read/write bit selects CPWM operating mode. Reset clears this bit so the
TPM operates in up-counting mode for input capture, output compare, and edge-aligned PWM functions. Setting
CPWMS reconfigures the TPM to operate in up-/down-counting mode for CPWM functions. Reset clears
CPWMS.
0 All TPMx channels operate as input capture, output compare, or edge-aligned PWM mode as selected by the
MSnB:MSnA control bits in each channel’s status and control register
1 All TPMx channels operate in center-aligned PWM mode
4:3
CLKS[B:A]
Clock Source Select — As shown in Table 11-2, this 2-bit field is used to disable the TPM system or select one
of three clock sources to drive the counter prescaler. The external source and the XCLK are synchronized to the
bus clock by an on-chip synchronization circuit.
2:0
PS[2:0]
Prescale Divisor Select — This 3-bit field selects one of eight divisors for the TPM clock input as shown in
Table 11-3. This prescaler is located after any clock source synchronization or clock source selection, so it affects
whatever clock source is selected to drive the TPM system.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
150
Freescale Semiconductor
Timer/Pulse-Width Modulator (S08TPMV2)
Table 11-2. TPM Clock Source Selection
CLKSB:CLKSA
TPM Clock Source to Prescaler Input
0:0
No clock selected (TPMx disabled)
0:1
Bus rate clock (BUSCLK)
1:0
Fixed system clock (XCLK)
1:1
External source (TPMxCLK)1,2
1
The maximum frequency that is allowed as an external clock is one-fourth of the bus
frequency.
2
If the external clock input is shared with channel n and is selected as the TPM clock source,
the corresponding ELSnB:ELSnA control bits must be set to 0:0 so channel n does not try to
use the same pin for a conflicting function.
Table 11-3. Prescale Divisor Selection
11.3.2
PS2:PS1:PS0
TPM Clock Source Divided-By
0:0:0
1
0:0:1
2
0:1:0
4
0:1:1
8
1:0:0
16
1:0:1
32
1:1:0
64
1:1:1
128
Timer Counter Registers (TPMxCNTH:TPMxCNTL)
The two read-only TPM counter registers contain the high and low bytes of the value in the TPM counter.
Reading either byte (TPMxCNTH or TPMxCNTL) latches the contents of both bytes into a buffer where
they remain latched until the other byte is read. This allows coherent 16-bit reads in either order. The
coherency mechanism is automatically restarted by an MCU reset, a write of any value to TPMxCNTH or
TPMxCNTL, or any write to the timer status/control register (TPMxSC).
Reset clears the TPM counter registers.
R
7
6
5
4
3
2
1
0
Bit 15
14
13
12
11
10
9
Bit 8
0
0
W
Reset
Any write to TPMxCNTH clears the 16-bit counter.
0
0
0
0
0
0
Figure 11-4. Timer Counter Register High (TPMxCNTH)
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
151
Timer/Pulse-Width Modulator (S08TPMV2)
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 11-5. Timer Counter Register Low (TPMxCNTL)
When background mode is active, the timer counter and the coherency mechanism are frozen such that the
buffer latches remain in the state they were in when the background mode became active even if one or
both bytes of the counter are read while background mode is active.
11.3.3
Timer Counter Modulo Registers (TPMxMODH:TPMxMODL)
The read/write TPM modulo registers contain the modulo value for the TPM counter. After the TPM
counter reaches the modulo value, the TPM counter resumes counting from 0x0000 at the next clock
(CPWMS = 0) or starts counting down (CPWMS = 1), and the overflow flag (TOF) becomes set. Writing
to TPMxMODH or TPMxMODL inhibits TOF and overflow interrupts until the other byte is written.
Reset sets the TPM counter modulo registers to 0x0000, which results in a free-running timer counter
(modulo disabled).
7
6
5
4
3
2
1
0
Bit 15
14
13
12
11
10
9
Bit 8
0
0
0
0
0
0
0
0
R
W
Reset
Figure 11-6. Timer 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 11-7. Timer Counter Modulo Register Low (TPMxMODL)
It is good practice to wait for an overflow interrupt so both bytes of the modulo register can be written well
before a new overflow. An alternative approach is to reset the TPM counter before writing to the TPM
modulo registers to avoid confusion about when the first counter overflow will occur.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
152
Freescale Semiconductor
Timer/Pulse-Width Modulator (S08TPMV2)
11.3.4
Timer Channel n Status and Control Register (TPMxCnSC)
TPMxCnSC contains the channel interrupt status flag and control bits that are used to configure the
interrupt enable, channel configuration, and pin function.
7
6
5
4
3
2
CHnF
CHnIE
MSnB
MSnA
ELSnB
ELSnA
0
0
0
0
0
0
R
1
0
0
0
0
0
W
Reset
= Unimplemented or Reserved
Figure 11-8. Timer Channel n Status and Control Register (TPMxCnSC)
Table 11-4. TPMxCnSC Register Field Descriptions
Field
Description
7
CHnF
Channel n Flag — When channel n is configured for input capture, this flag bit is set when an active edge occurs
on the channel n pin. When channel n is an output compare or edge-aligned PWM channel, CHnF is set when
the value in the TPM counter registers matches the value in the TPM channel n value registers. This flag is
seldom used with center-aligned PWMs because it is set every time the counter matches the channel value
register, which correspond to both edges of the active duty cycle period.
A corresponding interrupt is requested when CHnF is set and interrupts are enabled (CHnIE = 1). Clear CHnF
by reading TPMxCnSC while CHnF is set and then writing a 0 to CHnF. If another interrupt request occurs before
the clearing sequence is complete, the sequence is reset so CHnF would remain set after the clear sequence
was completed for the earlier CHnF. This is done so a CHnF interrupt request cannot be lost by clearing a
previous CHnF. Reset clears CHnF. Writing a 1 to CHnF has no effect.
0 No input capture or output compare event occurred on channel n
1 Input capture or output compare event occurred on channel n
6
CHnIE
Channel n Interrupt Enable — This read/write bit enables interrupts from channel n. Reset clears CHnIE.
0 Channel n interrupt requests disabled (use software polling)
1 Channel n interrupt requests enabled
5
MSnB
Mode Select B for TPM Channel n — When CPWMS = 0, MSnB = 1 configures TPM channel n for
edge-aligned PWM mode. For a summary of channel mode and setup controls, refer to Table 11-5.
4
MSnA
Mode Select A for TPM Channel n — When CPWMS = 0 and MSnB = 0, MSnA configures TPM channel n for
input capture mode or output compare mode. Refer to Table 11-5 for a summary of channel mode and setup
controls.
3:2
ELSn[B:A]
Edge/Level Select Bits — Depending on the operating mode for the timer channel as set by
CPWMS:MSnB:MSnA and shown in Table 11-5, these bits select the polarity of the input edge that triggers an
input capture event, select the level that will be driven in response to an output compare match, or select the
polarity of the PWM output.
Setting ELSnB:ELSnA to 0:0 configures the related timer pin as a general-purpose I/O pin unrelated to any timer
channel functions. This function is typically used to temporarily disable an input capture channel or to make the
timer pin available as a general-purpose I/O pin when the associated timer channel is set up as a software timer
that does not require the use of a pin.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
153
Timer/Pulse-Width Modulator (S08TPMV2)
Table 11-5. Mode, Edge, and Level Selection
CPWMS
MSnB:MSnA
ELSnB:ELSnA
X
XX
00
0
00
01
01
Input capture
Capture on falling edge only
11
Capture on rising or falling edge
00
Output
compare
Software compare only
Toggle output on compare
10
Clear output on compare
11
Set output on compare
10
XX
Capture on rising edge only
10
Edge-aligned
PWM
X1
1
Configuration
Pin not used for TPM channel; use as an external clock for the TPM or
revert to general-purpose I/O
01
1X
Mode
10
Center-aligned
PWM
X1
High-true pulses (clear output on compare)
Low-true pulses (set output on compare)
High-true pulses (clear output on compare-up)
Low-true pulses (set output on compare-up)
If the associated port pin is not stable for at least two bus clock cycles before changing to input capture
mode, it is possible to get an unexpected indication of an edge trigger. Typically, a program would clear
status flags after changing channel configuration bits and before enabling channel interrupts or using the
status flags to avoid any unexpected behavior.
11.3.5
Timer Channel Value Registers (TPMxCnVH:TPMxCnVL)
These read/write registers contain the captured TPM counter value of the input capture function or the
output compare value for the output compare or PWM functions. The channel value registers are cleared
by reset.
7
6
5
4
3
2
1
0
Bit 15
14
13
12
11
10
9
Bit 8
0
0
0
0
0
0
0
0
R
W
Reset
Figure 11-9. Timer 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 11-10. Timer Channel Value Register Low (TPMxCnVL)
In input capture mode, reading either byte (TPMxCnVH or TPMxCnVL) latches the contents of both bytes
into a buffer where they remain latched until the other byte is read. This latching mechanism also resets
(becomes unlatched) when the TPMxCnSC register is written.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
154
Freescale Semiconductor
Timer/Pulse-Width Modulator (S08TPMV2)
In output compare or PWM modes, writing to either byte (TPMxCnVH or TPMxCnVL) latches the value
into a buffer. When both bytes have been written, they are transferred as a coherent 16-bit value into the
timer channel value registers. This latching mechanism may be manually reset by writing to the
TPMxCnSC register.
This latching mechanism allows coherent 16-bit writes in either order, which is friendly to various
compiler implementations.
11.4
Functional Description
All TPM functions are associated with a main 16-bit counter that allows flexible selection of the clock
source and prescale divisor. A 16-bit modulo register also is associated with the main 16-bit counter in the
TPM. Each TPM channel is optionally associated with an MCU pin and a maskable interrupt function.
The TPM has center-aligned PWM capabilities controlled by the CPWMS control bit in TPMxSC. When
CPWMS is set to 1, timer counter TPMxCNT changes to an up-/down-counter and all channels in the
associated TPM act as center-aligned PWM channels. When CPWMS = 0, each channel can
independently be configured to operate in input capture, output compare, or buffered edge-aligned PWM
mode.
The following sections describe the main 16-bit counter and each of the timer operating modes (input
capture, output compare, edge-aligned PWM, and center-aligned PWM). Because details of pin operation
and interrupt activity depend on the operating mode, these topics are covered in the associated mode
sections.
11.4.1
Counter
All timer functions are based on the main 16-bit counter (TPMxCNTH:TPMxCNTL). This section
discusses selection of the clock source, up-counting vs. up-/down-counting, end-of-count overflow, and
manual counter reset.
After any MCU reset, CLKSB:CLKSA = 0:0 so no clock source is selected and the TPM is inactive.
Normally, CLKSB:CLKSA would be set to 0:1 so the bus clock drives the timer counter. The clock source
for the TPM can be selected to be off, the bus clock (BUSCLK), the fixed system clock (XCLK), or an
external input. The maximum frequency allowed for the external clock option is one-fourth the bus rate.
Refer to Section 11.3.1, “Timer Status and Control Register (TPMxSC)” and Table 11-2 for more
information about clock source selection.
When the microcontroller is in active background mode, the TPM temporarily suspends all counting until
the microcontroller returns to normal user operating mode. During stop mode, all TPM clocks are stopped;
therefore, the TPM is effectively disabled until clocks resume. During wait mode, the TPM continues to
operate normally.
The main 16-bit counter has two counting modes. When center-aligned PWM is selected (CPWMS = 1),
the counter operates in up-/down-counting mode. Otherwise, the counter operates as a simple up-counter.
As an up-counter, the main 16-bit counter counts from 0x0000 through its terminal count and then
continues with 0x0000. The terminal count is 0xFFFF or a modulus value in TPMxMODH:TPMxMODL.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
155
Timer/Pulse-Width Modulator (S08TPMV2)
When center-aligned PWM operation is specified, the counter counts upward from 0x0000 through its
terminal count and then counts downward to 0x0000 where it returns to up-counting. Both 0x0000 and the
terminal count value (value in TPMxMODH:TPMxMODL) are normal length counts (one timer clock
period long).
An interrupt flag and enable are associated with the main 16-bit counter. The timer overflow flag (TOF) is
a software-accessible indication that the timer counter has overflowed. The enable signal selects between
software polling (TOIE = 0) where no hardware interrupt is generated, or interrupt-driven operation
(TOIE = 1) where a static hardware interrupt is automatically generated whenever the TOF flag is 1.
The conditions that cause TOF to become set depend on the counting mode (up or up/down). In
up-counting mode, the main 16-bit counter counts from 0x0000 through 0xFFFF and overflows to 0x0000
on the next counting clock. TOF becomes set at the transition from 0xFFFF to 0x0000. When a modulus
limit is set, TOF becomes set at the transition from the value set in the modulus register to 0x0000. When
the main 16-bit counter is operating in up-/down-counting mode, the TOF flag gets set as the counter
changes direction at the transition from the value set in the modulus register and the next lower count
value. This corresponds to the end of a PWM period. (The 0x0000 count value corresponds to the center
of a period.)
Because the HCS08 MCU is an 8-bit architecture, a coherency mechanism is built into the timer counter
for read operations. Whenever either byte of the counter is read (TPMxCNTH or TPMxCNTL), both bytes
are captured into a buffer so when the other byte is read, the value will represent the other byte of the count
at the time the first byte was read. The counter continues to count normally, but no new value can be read
from either byte until both bytes of the old count have been read.
The main timer counter can be reset manually at any time by writing any value to either byte of the timer
count TPMxCNTH or TPMxCNTL. Resetting the counter in this manner also resets the coherency
mechanism in case only one byte of the counter was read before resetting the count.
11.4.2
Channel Mode Selection
Provided CPWMS = 0 (center-aligned PWM operation is not specified), the MSnB and MSnA control bits
in the channel n status and control registers determine the basic mode of operation for the corresponding
channel. Choices include input capture, output compare, and buffered edge-aligned PWM.
11.4.2.1
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.
When either byte of the 16-bit capture register is read, both bytes are latched into a buffer to support
coherent 16-bit accesses regardless of order. The coherency sequence can be manually reset by writing to
the channel status/control register (TPMxCnSC).
An input capture event sets a flag bit (CHnF) that can optionally generate a CPU interrupt request.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
156
Freescale Semiconductor
Timer/Pulse-Width Modulator (S08TPMV2)
11.4.2.2
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.
In output compare mode, values are transferred to the corresponding timer channel value registers only
after both 8-bit bytes of a 16-bit register have been written. This coherency sequence can be manually reset
by writing to the channel status/control register (TPMxCnSC).
An output compare event sets a flag bit (CHnF) that can optionally generate a CPU interrupt request.
11.4.2.3
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 setting in the modulus register
(TPMxMODH:TPMxMODL). The duty cycle is determined by the setting in the timer channel value
register (TPMxCnVH:TPMxCnVL). The polarity of this PWM signal is determined by the setting in the
ELSnA control bit. Duty cycle cases of 0 percent and 100 percent are possible.
As Figure 11-11 shows, the output compare value in the TPM channel registers determines the pulse width
(duty cycle) of the PWM signal. The time between the modulus overflow and the output compare is the
pulse width. If ELSnA = 0, the counter overflow forces the PWM signal high and the output compare
forces the PWM signal low. If ELSnA = 1, the counter overflow forces the PWM signal low and the output
compare forces the PWM signal high.
OVERFLOW
OVERFLOW
OVERFLOW
PERIOD
PULSE
WIDTH
TPMxC
OUTPUT
COMPARE
OUTPUT
COMPARE
OUTPUT
COMPARE
Figure 11-11. PWM Period and Pulse Width (ELSnA = 0)
When the channel value register is set to 0x0000, the duty cycle is 0 percent. By setting the timer channel
value register (TPMxCnVH:TPMxCnVL) to a value greater than the modulus setting, 100% duty cycle
can be achieved. This implies that the modulus setting must be less than 0xFFFF to get 100% duty cycle.
Because the HCS08 is a family of 8-bit MCUs, the settings in the timer channel registers are buffered to
ensure coherent 16-bit updates and to avoid unexpected PWM pulse widths. Writes to either register,
TPMxCnVH or TPMxCnVL, write to buffer registers. In edge-PWM mode, values are transferred to the
corresponding timer channel registers only after both 8-bit bytes of a 16-bit register have been written and
the value in the TPMxCNTH:TPMxCNTL counter is 0x0000. (The new duty cycle does not take effect
until the next full period.)
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
157
Timer/Pulse-Width Modulator (S08TPMV2)
11.4.3
Center-Aligned PWM Mode
This type of PWM output uses the up-/down-counting mode of the timer counter (CPWMS = 1). The
output compare value in TPMxCnVH:TPMxCnVL determines the pulse width (duty cycle) of the PWM
signal and the period is determined by the value in TPMxMODH:TPMxMODL.
TPMxMODH:TPMxMODL must be kept in the range of 0x0001 to 0x7FFF because values outside this
range can produce ambiguous results. ELSnA will determine the polarity of the CPWM output.
pulse width = 2 x (TPMxCnVH:TPMxCnVL)
Eqn. 11-1
period = 2 x (TPMxMODH:TPMxMODL);
for TPMxMODH:TPMxMODL = 0x0001–0x7FFF
Eqn. 11-2
If the channel value register TPMxCnVH:TPMxCnVL is zero or negative (bit 15 set), the duty cycle will
be 0%. If TPMxCnVH:TPMxCnVL is a positive value (bit 15 clear) and is greater than the (nonzero)
modulus setting, the duty cycle will be 100% because the duty cycle compare will never occur. This
implies the usable range of periods set by the modulus register is 0x0001 through 0x7FFE (0x7FFF if
generation of 100% duty cycle is not necessary). This is not a significant limitation because the resulting
period is much longer than required for normal applications.
TPMxMODH:TPMxMODL = 0x0000 is a special case that must not be used with center-aligned PWM
mode. When CPWMS = 0, this case corresponds to the counter running free from 0x0000 through 0xFFFF,
but when CPWMS = 1 the counter needs a valid match to the modulus register somewhere other than at
0x0000 in order to change directions from up-counting to down-counting.
Figure 11-12 shows the output compare value in the TPM channel registers (multiplied by 2), which
determines the pulse width (duty cycle) of the CPWM signal. If ELSnA = 0, the compare match while
counting up forces the CPWM output signal low and a compare match while counting down forces the
output high. The counter counts up until it reaches the modulo setting in TPMxMODH:TPMxMODL, then
counts down until it reaches zero. This sets the period equal to two times TPMxMODH:TPMxMODL.
COUNT =
TPMxMODH:TPMx
OUTPUT
COMPARE
(COUNT DOWN)
COUNT = 0
OUTPUT
COMPARE
(COUNT UP)
COUNT =
TPMxMODH:TPMx
TPM1C
PULSE WIDTH
2x
2x
PERIOD
Figure 11-12. CPWM Period and Pulse Width (ELSnA = 0)
Center-aligned PWM outputs typically produce less noise than edge-aligned PWMs because fewer I/O pin
transitions are lined up at the same system clock edge. This type of PWM is also required for some types
of motor drives.
Because the HCS08 is a family of 8-bit MCUs, the settings in the timer channel registers are buffered to
ensure coherent 16-bit updates and to avoid unexpected PWM pulse widths. Writes to any of the registers,
TPMxMODH, TPMxMODL, TPMxCnVH, and TPMxCnVL, actually write to buffer registers. Values are
MC9S08QD4 Series MCU Data Sheet, Rev. 3
158
Freescale Semiconductor
Timer/Pulse-Width Modulator (S08TPMV2)
transferred to the corresponding timer channel registers only after both 8-bit bytes of a 16-bit register have
been written and the timer counter overflows (reverses direction from up-counting to down-counting at the
end of the terminal count in the modulus register). This TPMxCNT overflow requirement only applies to
PWM channels, not output compares.
Optionally, when TPMxCNTH:TPMxCNTL = TPMxMODH:TPMxMODL, the TPM can generate a TOF
interrupt at the end of this count. The user can choose to reload any number of the PWM buffers, and they
will all update simultaneously at the start of a new period.
Writing to TPMxSC cancels any values written to TPMxMODH and/or TPMxMODL and resets the
coherency mechanism for the modulo registers. Writing to TPMxCnSC cancels any values written to the
channel value registers and resets the coherency mechanism for TPMxCnVH:TPMxCnVL.
11.5
TPM Interrupts
The TPM generates an optional interrupt for the main counter overflow and an interrupt for each channel.
The meaning of channel interrupts depends on the mode of operation for each channel. If the channel is
configured for input capture, the interrupt flag is set each time the selected input capture edge is
recognized. If the channel is configured for output compare or PWM modes, the interrupt flag is set each
time the main timer counter matches the value in the 16-bit channel value register. See the Resets,
Interrupts, and System Configuration chapter for absolute interrupt vector addresses, priority, and local
interrupt mask control bits.
For each interrupt source in the TPM, a flag bit is set on recognition of the interrupt condition such as timer
overflow, channel input capture, or output compare events. This flag may be read (polled) by software to
verify that the action has occurred, or an associated enable bit (TOIE or CHnIE) can be set to enable
hardware interrupt generation. While the interrupt enable bit is set, a static interrupt will be generated
whenever the associated interrupt flag equals 1. It is the responsibility of user software to perform a
sequence of steps to clear the interrupt flag before returning from the interrupt service routine.
11.5.1
Clearing Timer Interrupt Flags
TPM interrupt flags are cleared by a 2-step process that includes a read of the flag bit while it is set (1)
followed by a write of 0 to the bit. If a new event is detected between these two steps, the sequence is reset
and the interrupt flag remains set after the second step to avoid the possibility of missing the new event.
11.5.2
Timer Overflow Interrupt Description
The conditions that cause TOF to become set depend on the counting mode (up or up/down). In
up-counting mode, the 16-bit timer counter counts from 0x0000 through 0xFFFF and overflows to 0x0000
on the next counting clock. TOF becomes set at the transition from 0xFFFF to 0x0000. When a modulus
limit is set, TOF becomes set at the transition from the value set in the modulus register to 0x0000. When
the counter is operating in up-/down-counting mode, the TOF flag gets set as the counter changes direction
at the transition from the value set in the modulus register and the next lower count value. This corresponds
to the end of a PWM period. (The 0x0000 count value corresponds to the center of a period.)
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
159
Timer/Pulse-Width Modulator (S08TPMV2)
11.5.3
Channel Event Interrupt Description
The meaning of channel interrupts depends on the current mode of the channel (input capture, output
compare, edge-aligned PWM, or center-aligned PWM).
When a channel is configured as an input capture channel, the ELSnB:ELSnA control bits select rising
edges, falling edges, any edge, or no edge (off) as the edge that triggers an input capture event. When the
selected edge is detected, the interrupt flag is set. The flag is cleared by the 2-step sequence described in
Section 11.5.1, “Clearing Timer Interrupt Flags.”
When a channel is configured as an output compare channel, the interrupt flag is set each time the main
timer counter matches the 16-bit value in the channel value register. The flag is cleared by the 2-step
sequence described in Section 11.5.1, “Clearing Timer Interrupt Flags.”
11.5.4
PWM End-of-Duty-Cycle Events
For channels that are configured for PWM operation, there are two possibilities:
• When the channel is configured for edge-aligned PWM, the channel flag is set when the timer
counter matches the channel value register that marks the end of the active duty cycle period.
• When the channel is configured for center-aligned PWM, the timer count matches the channel
value register twice during each PWM cycle. In this CPWM case, the channel flag is set at the start
and at the end of the active duty cycle, which are the times when the timer counter matches the
channel value register.
The flag is cleared by the 2-step sequence described in Section 11.5.1, “Clearing Timer Interrupt Flags.”
MC9S08QD4 Series MCU Data Sheet, Rev. 3
160
Freescale Semiconductor
Chapter 12
Development Support
12.1
Introduction
Development support systems in the HCS08 include the background debug controller (BDC). The BDC
provides a single-wire debug interface to the target MCU that provides a convenient interface for
programming the on-chip flash and other nonvolatile memories. The BDC is also the primary debug
interface for development and allows non-intrusive access to memory data and traditional debug features
such as CPU register modify, breakpoints, and single instruction trace commands.
In the HCS08 Family, address and data bus signals are not available on external pins (not even in test
modes). Debug is done through commands fed into the target MCU via the single-wire background debug
interface. The debug module provides a means to selectively trigger and capture bus information so an
external development system can reconstruct what happened inside the MCU on a cycle-by-cycle basis
without having external access to the address and data signals.
12.1.1
Forcing Active Background
The method for forcing active background mode depends on the specific HCS08 derivative. For the
MC9S08QD4 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.
12.1.2
Module Configuration
The alternative BDC clock source for MC9S08QD4 series is the ICGCLK. See Chapter 9, “Internal Clock
Source (S08ICSV1),” for more information about ICGCLK and how to select clock sources.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
161
Development Support
12.1.3
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
12.2
Background Debug Controller (BDC)
All MCUs in the HCS08 Family contain a single-wire background debug interface that supports in-circuit
programming of on-chip nonvolatile memory and sophisticated non-intrusive debug capabilities. Unlike
debug interfaces on earlier 8-bit MCUs, this system does not interfere with normal application resources.
It does not use any user memory or locations in the memory map and does not share any on-chip
peripherals.
BDC commands are divided into two groups:
• Active background mode commands require that the target MCU is in active background mode (the
user program is not running). Active background mode commands allow the CPU registers to be
read or written, and allow the user to trace one user instruction at a time, or GO to the user program
from active background mode.
• Non-intrusive commands can be executed at any time even while the user’s program is running.
Non-intrusive commands allow a user to read or write MCU memory locations or access status and
control registers within the background debug controller.
Typically, a relatively simple interface pod is used to translate commands from a host computer into
commands for the custom serial interface to the single-wire background debug system. Depending on the
development tool vendor, this interface pod may use a standard RS-232 serial port, a parallel printer port,
or some other type of communications such as a universal serial bus (USB) to communicate between the
host PC and the pod. The pod typically connects to the target system with ground, the BKGD pin, RESET,
and sometimes VDD. An open-drain connection to reset allows the host to force a target system reset,
which is useful to regain control of a lost target system or to control startup of a target system before the
on-chip nonvolatile memory has been programmed. Sometimes VDD can be used to allow the pod to use
power from the target system to avoid the need for a separate power supply. However, if the pod is powered
separately, it can be connected to a running target system without forcing a target system reset or otherwise
disturbing the running application program.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
162
Freescale Semiconductor
Development Support
BKGD 1
2 GND
NO CONNECT 3
4 RESET
NO CONNECT 5
6 VDD
Figure 12-1. BDM Tool Connector
12.2.1
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 12.2.2,
“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 12.2.2, “Communication Details,” for more detail.
When no debugger pod is connected to the 6-pin BDM interface connector, the internal pullup on BKGD
chooses normal operating mode. When a 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.
12.2.2
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
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
163
Development Support
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.
Figure 12-2 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 12-2. BDC Host-to-Target Serial Bit Timing
Figure 12-3 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.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
164
Freescale Semiconductor
Development Support
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 12-3. BDC Target-to-Host Serial Bit Timing (Logic 1)
Figure 12-4 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.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
165
Development Support
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 12-4. BDM Target-to-Host Serial Bit Timing (Logic 0)
12.2.3
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 12-1 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 12-1 to describe the coding structure of the BDC commands.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
166
Freescale Semiconductor
Development Support
/
d
AAAA
RD
WD
RD16
WD16
SS
CC
RBKP
=
=
=
=
=
=
=
=
=
=
WBKP
=
Commands begin with an 8-bit hexadecimal command code in the host-to-target
direction (most significant bit first)
separates parts of the command
delay 16 target BDC clock cycles
a 16-bit address in the host-to-target direction
8 bits of read data in the target-to-host direction
8 bits of write data in the host-to-target direction
16 bits of read data in the target-to-host direction
16 bits of write data in the host-to-target direction
the contents of BDCSCR in the target-to-host direction (STATUS)
8 bits of write data for BDCSCR in the host-to-target direction (CONTROL)
16 bits of read data in the target-to-host direction (from BDCBKPT breakpoint
register)
16 bits of write data in the host-to-target direction (for BDCBKPT breakpoint register)
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
167
Development Support
Table 12-1. 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.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
168
Freescale Semiconductor
Development Support
The SYNC command is unlike other BDC commands because the host does not necessarily know the
correct communications speed to use for BDC communications until after it has analyzed the response to
the SYNC command.
To issue a SYNC command, the host:
• Drives the BKGD pin low for at least 128 cycles of the slowest possible BDC clock (The slowest
clock is normally the reference oscillator/64 or the self-clocked rate/64.)
• Drives BKGD high for a brief speedup pulse to get a fast rise time (This speedup pulse is typically
one cycle of the fastest clock in the system.)
• Removes all drive to the BKGD pin so it reverts to high impedance
• Monitors the BKGD pin for the sync response pulse
The target, upon detecting the SYNC request from the host (which is a much longer low time than would
ever occur during normal BDC communications):
• Waits for BKGD to return to a logic high
• Delays 16 cycles to allow the host to stop driving the high speedup pulse
• Drives BKGD low for 128 BDC clock cycles
• Drives a 1-cycle high speedup pulse to force a fast rise time on BKGD
• Removes all drive to the BKGD pin so it reverts to high impedance
The host measures the low time of this 128-cycle sync response pulse and determines the correct speed for
subsequent BDC communications. Typically, the host can determine the correct communication speed
within a few percent of the actual target speed and the communication protocol can easily tolerate speed
errors of several percent.
12.2.4
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.
12.3
Register Definition
This section contains the descriptions of the BDC registers and control bits.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
169
Development Support
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.
12.3.1
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.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
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Freescale Semiconductor
Development Support
12.3.1.1
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 12-5. BDC Status and Control Register (BDCSCR)
Table 12-2. 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
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
171
Development Support
Table 12-2. 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 MC9S08QD4 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
12.3.1.2
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 12.2.4, “BDC Hardware Breakpoint.”
12.3.2
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.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
172
Freescale Semiconductor
Development Support
R
7
6
5
4
3
2
1
0
0
0
0
0
0
0
0
0
BDFR1
W
Reset
0
0
0
0
0
0
0
0
= Unimplemented or Reserved
1
BDFR is writable only through serial background mode debug commands, not from user programs.
Figure 12-6. System Background Debug Force Reset Register (SBDFR)
Table 12-3. 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.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
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MC9S08QD4 Series MCU Data Sheet, Rev. 3
174
Freescale Semiconductor
Appendix A
Electrical Characteristics
A.1
Introduction
This chapter contains electrical and timing specifications.
A.2
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-1 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) or the programmable
pull-up resistor associated with the pin is enabled.
Table A-1. Absolute Maximum Ratings
Rating
Symbol
Value
Unit
Supply voltage
VDD
–0.3 to +5.8
V
Maximum current into VDD
IDD
120
mA
Digital 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
Tstg
–55 to 150
°C
Storage temperature range
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 V
SS 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).
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
175
Appendix A Electrical Characteristics
A.3
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 voltage regulator circuits 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-2. Thermal Characteristics
Rating
Symbol
Value
Unit
TA
TL to TH
–40 to 125
°C
Thermal resistance (single-layer board)
8-pin PDIP
8-pin NB SOIC
θJA
113
150
°C/W
Thermal resistance (four-layer board)
8-pin PDIP
8-pin NB SOIC
θJA
72
87
°C/W
Operating temperature range
(packaged)
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 3 by measuring
PD (at equilibrium) for a known TA. Using this value of K, the values of PD and TJ can be obtained by
solving Equation A-1 and Equation A-2 iteratively for any value of TA.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
176
Freescale Semiconductor
Appendix A Electrical Characteristics
A.4
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), the machine model (MM) and the charge device model (CDM).
A device is defined as a failure if after exposure to ESD pulses the device no longer meets the device
specification. Complete DC parametric and functional testing is performed per the applicable device
specification at room temperature followed by hot temperature, unless specified otherwise in the device
specification.
Table A-3. ESD and Latch-up Test Conditions
Model
Human
Body
Machine
Latch-up
Description
Symbol
Value
Unit
Series resistance
R1
1500
Ω
Storage capacitance
C
100
pF
Number of pulses per pin
—
3
Series resistance
R1
0
Ω
Storage capacitance
C
200
pF
Number of pulses per pin
—
3
Minimum input voltage limit
– 2.5
V
Maximum input voltage limit
7.5
V
Table A-4. ESD and Latch-Up Protection Characteristics
No.
1
A.5
Rating1
Symbol
Min
Max
Unit
1
Human body model (HBM)
VHBM
± 2000
—
V
2
Machine model (MM)
VMM
± 200
—
V
3
Charge device model (CDM)
VCDM
± 500
—
V
4
Latch-up current at TA = 85°C
ILAT
± 100
—
mA
Parameter is achieved by design characterization on a small sample size from typical devices
under typical conditions unless otherwise noted.
DC Characteristics
This section includes information about power supply requirements and I/O pin characteristics.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
177
Appendix A Electrical Characteristics
Table A-5. DC Characteristics (Temperature Range = –40 to 125°C Ambient)
Parameter
Supply voltage (run, wait, and stop modes.)
Symbol
Min
VDD
2.7
Minimum RAM retention supply voltage applied to VDD
VRAM
Low-voltage detection threshold — high range
(Consumer and Industrial MC9S08QDx)
VLVDH
VDD falling
VDD rising)
VPOR
Typical
1, 2
4.2
4.3
4.3
4.4
Max
Unit
5.5
V
—
V
4.4
4.5
Low-voltage detection threshold — high range
(Automotive S9S08QDx)
V
V
V
(VDD falling)
–40°C to 0°C
0 to 125°C
(VDD rising)
–40°C to 0°C
0 to 125°C
4.175
4.2
4.3
4.4
4.4
4.5
4.275
4.3
4.3
4.4
4.4
4.5
2.48
2.54
2.56
2.62
2.64
2.7
4.2
4.3
4.3
4.4
4.4
4.5
Low-voltage detection threshold — low range
(VDD falling)
(VDD rising)
Low-voltage warning threshold — high range
(Consumer and Industrial MC9S08QDx)
VLVDL
VLVWH
(VDD falling)
(VDD rising)
Low-voltage warning threshold — high range
(Automotive S9S08QDx)
V
V
V
V
V
(VDD falling)
–40°C to 0°C
0 to 125°C
(VDD rising)
–40°C to 0°C
0 to 125°C
4.175
4.2
4.3
4.4
4.4
4.5
4.275
4.3
4.3
4.4
4.4
4.5
VLVWL
2.48
2.54
2.56
2.62
2.64
2.7
V
V
Vhys
—
—
100
60
—
—
mV
mV
VBG
1.19
1.20
1.21
V
1.18
1.20
1.215
V
Low-voltage warning threshold — low range
(VDD falling)
(VDD rising)
Low-voltage inhibit reset/recover hysteresis
5V
3V
Bandgap Voltage Reference
(Consumer and Industrial MC9S08QDx)
Factory trimmed at VDD = 3.0V, Temp = 25°C
Bandgap Voltage Reference (S9S08QDx)
Factory trimmed at VDD = 3.0V, Temp = 25°C
–40°C to 125°C
Input high voltage (2.7 V ≤ VDD ≤ 5.5 V) (all digital inputs)
VIH
0.7 × VDD
—
V
Input low voltage (2.7 V ≤ VDD ≤ 5.5 V) (all digital inputs)
VIL
—
0.3 × VDD
V
Input hysteresis (all digital inputs)
Vhys
0.06 × VDD
—
V
Input leakage current (Per pin)
VIn = VDD or VSS, all input only pins
|IIn|
—
1.0
μA
0.025
MC9S08QD4 Series MCU Data Sheet, Rev. 3
178
Freescale Semiconductor
Appendix A Electrical Characteristics
Table A-5. DC Characteristics (continued)(Temperature Range = –40 to 125°C Ambient)
Parameter
Symbol
Min
Typical
Max
Unit
High impedance (off-state) leakage current (per pin)
VIn = VDD or VSS, all input/output
|IOZ|
—
0.025
1.0
μA
Internal pullup resistors3
RPU
17.5
52.5
κW
Internal pulldown resistor (IRQ)
RPD
17.5
52.5
κW
VOH
VDD – 1.5
VDD – 1.5
VDD – 0.8
VDD – 0.8
—
—
—
—
—
—
—
—
VDD – 1.5
VDD – 1.5
VDD – 0.8
VDD – 0.8
—
—
—
—
—
—
—
—
—
—
—
—
100
60
—
—
—
—
—
—
—
—
1.5
1.5
0.8
0.8
—
—
—
—
—
—
—
—
1.5
1.5
0.8
0.8
—
—
—
—
100
60
mA
—
—
0.2
5
mA
mA
—
7
pF
Output high voltage — Low Drive (PTxDSn = 0)
5 V, ILoad = –2 mA
3 V, ILoad = –0.6 mA
5 V, ILoad = –0.4 mA
3 V, ILoad = –0.24 mA
V
Output high voltage — High Drive (PTxDSn = 1)
5 V, ILoad = –10 mA
3 V, ILoad = –3 mA
5 V, ILoad = –2 mA
3 V, ILoad = –0.4 mA
Maximum total IOH for all port pins
5V
3V
|IOHT|
Output low voltage — Low Drive (PTxDSn = 0)
5 V, ILoad = 2 mA
3 V, ILoad = 0.6 mA
5 V, ILoad = 0.4 mA
3 V, ILoad = 0.24 mA
VOL
Output low voltage — High Drive (PTxDSn = 1)
5 V, ILoad = 10 mA
3 V, ILoad = 3 mA
5 V, ILoad = 2 mA
3 V, ILoad = 0.4 mA
Maximum total IOL for all port pins
5V
3V
1
2
3
4
5
6
IOLT
dc injection current(2), 4, 5, 6
VIN < VSS, VIN > VDD
Single pin limit
Total MCU limit, includes sum of all stressed pins
|IIC|
Input capacitance (all non-supply pins)
CIn
mA
V
RAM will retain data down to POR voltage. RAM data not guaranteed to be valid following a POR.
This parameter is characterized and not tested on each device.
Measurement condition for pull resistors: VIn = VSS for pullup and VIn = VDD for pulldown.
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.
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).
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
179
Appendix A Electrical Characteristics
Typical Low-side Driver (LDS) Characteristics,
VDD = 5.0 V, PORTA
14
125
12
105
85
IOL/mA
10
8
25
6
0
4
–40
2
0
0
0.8
0.4
1.2
2
1.6
2.4
2.8
VOL/V
Figure A-1. Typical Low-Side Driver (Sink) Characteristics
Low Drive (PTxDSn = 0), VDD = 5.0V, VOL vs. IOL
Typical Low-side Driver (LDS) Characteristics,
VDD = 3.0 V, PORTA
6
125
5
105
IOL/mA
4
85
25
3
0
2
–40
1
0
0
0.2
0.4
0.6
0.8
VOL/V
1
1.2
1.4
–1.6
Figure A-2. Typical Low-Side Driver (Sink) Characteristics
Low Drive (PTxDSn = 0), VDD = 3.0 V, VOL vs. IOL
MC9S08QD4 Series MCU Data Sheet, Rev. 3
180
Freescale Semiconductor
Appendix A Electrical Characteristics
Typical Low-side Driver (HDS) Characteristics,
VDD = 5.0 V, PORTA
40
35
125
105
85
25
0
–40
30
IOL/mA
25
20
15
10
5
0
0
0.4
0.8
1.2
1.6
VOL/V
2
2.4
2.8
Figure A-3. Typical Low-Side Driver (Sink) Characteristics
High Drive (PTxDSn = 1), VDD = 5.0 V, VOL vs. IOL
Typical Low-side Driver (HDS) Characteristics,
VDD = 3.0 V, PORTA
14
125
12
105
85
8
25
6
0
4
–40
IOL/mA
10
2
0
0
0.2
0.4
0.6
0.8
VOL/V
1
1.2
1.4
1.6
Figure A-4. Typical Low-Side Driver (Sink) Characteristics
High Drive (PTxDSn = 1), VDD = 3.0 V, VOL vs. IOL
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
181
Appendix A Electrical Characteristics
Typical High-side Driver (LDS) Characteristics,
VDD = 5.0 V, PORTA
IOH/mA
0
–1
125
–2
105
–3
85
–4
25
–5
0
–6
–40
–7
–8
2.4
2.8
3.2
3.6
4
VOH/V
4.4
4.8
5.2
Figure A-5. Typical High-Side Driver (Source) Characteristics
Low Drive (PTxDSn = 0), VDD = 5.0 V, VOH vs. IOH
Typical High-side Driver (LDS) Characteristics,
VDD = 3.0 V, PORTA
0
125
–0.5
105
IOH/mA
–1
85
25
–1.5
0
–2
–40
–2.5
–3
1.6
1.8
2
2.2
2.4
VOH/V
2.6
2.8
3
Figure A-6. Typical High-Side Driver (Source) Characteristics
Low Drive (PTxDSn = 0), VDD = 3.0 V, VOH vs. IOH
MC9S08QD4 Series MCU Data Sheet, Rev. 3
182
Freescale Semiconductor
Appendix A Electrical Characteristics
Typical High-side Driver (HDS) Characteristics,
VDD = 5.0 V, PORTA
0
125
105
85
25
0
–40
–5
IOH/mA
–10
–15
–20
–25
–30
2.4
2.8
3.2
4
3.6
VOH/V
4.4
4.8
5.2
Figure A-7. Typical High-Side Driver (Source) Characteristics
High Drive (PTxDSn = 1), VDD = 5.0 V, VOH vs. IOH
Typical High-side Driver (HDS) Characteristics,
VDD = 3.0 V, PORTA
0
125
105
85
25
0
–40
–2
IOH/mA
–4
–6
–8
–10
–12
1.6
1.8
2
2.2
2.4
VOH/V
2.6
2.8
3
Figure A-8. Typical High-Side Driver (Source) Characteristics
High Drive (PTxDSn = 1), VDD = 3.0 V, VOH vs. IOH
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
183
Appendix A Electrical Characteristics
A.6
Supply Current Characteristics
This section includes information about power supply current in various operating modes
Table A-6. Supply Current Characteristics
Parameter
Symbol
Run supply current3 measured at
(CPU clock = 2 MHz, fBus = 1 MHz)
RIDD
Run supply current5 measured at
(CPU clock = 16 MHz, fBus = 8 MHz)
RIDD
Wait mode supply current7 measured at
(CPU clock = 16 MHz, fBus = 8 MHz)
WIDD
Stop2 mode supply current
(Consumer and Industrial MC9S08QDx)
–40 to 85°C
–40 to 125°C
–40 to 85°C
–40 to 125°C
–40 to 85°C
–40 to 125°C
–40 to 85°C
–40 to 125°C
Stop3 mode supply current
(Consumer and Industrial MC9S08QDx)
–40 to 85° C
–40 to 125°C
–40 to 85° C
–40 to 125°C
5
0.95
1.54
3
0.90
1.5
5
3.5
56
3
3.4
5
5
1.55
2.2
3
1.50
2.2
5
0.80
7.58
20 4
3
0.80
7.08
15
5
0.80
7.59
25 4
3
0.80
7.08
20
5
0.90
8.08
254
3
0.90
7.18
20
5
0.90
8.08
304
3
0.90
7.18
25
5
400
nA
3
350
nA
5
110
μA
S3IDD s
Stop3 mode supply current
(Automotive S9S08QDx)
–40 to 85° C
–40 to 125°C
–40 to 85° C
–40 to 125°C
RTI adder to stop2 or stop310, 25°C
LVD adder to stop3 (LVDE = LVDSE = 1)
Adder to stop3 for oscillator enabled (IREFSTEN = 1)
2
Max2
S2IDD
Stop2 mode supply current
(Automotive S9S08QDx)
1
Typical1
VDD (V)
Unit
mA
mA
mA
μA
μA
μA
μA
μA
μA
μA
μA
3
90
μA
5
75
μA
3
65
μA
Typicals are measured at 25°C.
Values given here are preliminary estimates prior to completing characterization.
MC9S08QD4 Series MCU Data Sheet, Rev. 3
184
Freescale Semiconductor
Appendix A Electrical Characteristics
3
All modules except ADC active, and does not include any dc loads on port pins
Every unit tested to this parameter. All other values in the Max column are guaranteed by characterization.
5
All modules except ADC active, and does not include any dc loads on port pins
6
Every unit tested to this parameter. All other values in the Max column are guaranteed by characterization.
7 Most customers are expected to find that the auto-wakeup from a stop mode can be used instead of the higher current wait
mode.
8 This parameter is characterized and not tested on each device.
9
This parameter is characterized and not tested on each device.
10
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 3 V with fBus = 1 MHz.
4
Typical RIDD (VDD=5.0 V, ADC off) vs. Bus Freq.
4.00
3.50
125
105
85
25
0
–40
RIDD/mA
3.00
2.50
2.00
1.50
1.00
0.50
0.00
0
2
4
6
8
10
Bus/MHz
Figure A-9. Typical Run IDD vs. Bus Freq. (FEI) (ADC off)
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
185
Appendix A Electrical Characteristics
A.7
Internal Clock Source Characteristics
Table A-7. Internal Clock Source Specifications
Symbol
Min
Typ1
Max
Unit
Average internal reference frequency - untrimmed
fint_ut
25
31.25
41.66
kHz
Average internal reference frequency - trimmed
fint_t
—
31.25
—
kHz
DCO output frequency range - untrimmed
fdco_ut
12.8
16
21.33
MHz
DCO output frequency range - trimmed
fdco_t
—
16
—
MHz
—
—
± 0.2
Characteristic
Resolution of trimmed DCO output frequency at fixed voltage and
temperature (Consumer and Industrial MC9S08QDx)2
Resolution of trimmed DCO output frequency at fixed voltage and
temperature (Automotive S9S08QDx)2
–40°C to 0°C
0 to 125°C
Δfdco_res_t
Total deviation of trimmed DCO output frequency over voltage and
temperature 2
Consumer and Industrial MC9S08QDx
Automotive S9S08QDx
Δfdco_t
FLL acquisition time 2,3
tacquire
Long term Jitter of DCO output clock (averaged over 2 ms interval) 4
CJitter
%fdco
—
—
—
—
—
—
± 0.3
± 0.2
±2
±3
%fdco
1
ms
0.6
%fdco
1
Data in Typical column was characterized at 3.0 V and 3.0 V, 25°C or is typical recommended value.
Characterized, but not tested.
3 This specification applies to any time the FLL reference source or reference divider is changed, trim value changed or changing
from FLL disabled (FBELP, FBILP) to FLL enabled (FEI, FEE, FBE, FBI). 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 f
BUS.
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.
2
MC9S08QD4 Series MCU Data Sheet, Rev. 3
186
Freescale Semiconductor
Appendix A Electrical Characteristics
Deviation of DCO Output from Trimmed Frequency
(8 MHz, 5.5 V)
0.80%
0.70%
0.60%
0.50%
Deviation
0.40%
0.30%
0.20%
0.10%
0.00%
–0.10%
–0.20%
–0.30%
–0.40%
–40
–20
0
20
40
60
Temp. /C
80
100
120
140
Figure A-10. Typical Deviation of DCO Output vs. Temperature
Deviation of DCO Output from Trimmed Frequency
(8 MHz, 25 °C)
0.20%
0.15%
Deviation
0.10%
0.05%
0.00%
–0.05%
–0.10%
–0.15%
–0.20%
2.5
3
3.5
4
4.5
5
5.5
6
VDD / V
Figure A-11. Typical Deviation of DCO Output vs. Operating Voltage
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
187
Appendix A Electrical Characteristics
A.8
AC Characteristics
This section describes AC timing characteristics for each peripheral system.
A.8.1
Control Timing
Table A-8. Control Timing
Symbol
Min
Typical1
Max
Unit
Bus frequency (tcyc = 1/fBus)
fBus
1
—
8
MHz
Real-time interrupt internal oscillator period
tRTI
700
—
1300
μs
textrst
100
—
—
ns
IRQ pulse width
Asynchronous path2
Synchronous path3
tILIH, tIHIL
100
1.5 tcyc
—
—
KBIPx pulse width
Asynchronous path2
Synchronous path3
tILIH, tIHIL
100
1.5 tcyc
—
—
ns
—
—
3
30
—
—
ns
Parameter
External reset pulse width2
Port rise and fall time (load = 50 pF)4
Slew rate control disabled (PTxSE = 0)
Slew rate control enabled (PTxSE = 1)
ns
tRise, tFall
BKGD/MS setup time after issuing background debug force
reset to enter user or BDM modes
tMSSU
500
—
—
ns
BKGD/MS hold time after issuing background debug force
reset to enter user or BDM modes 5
tMSH
100
—
—
μs
1
Data in Typical column was characterized at 3.0 V, 25°C.
This is the shortest pulse that is guaranteed to be recognized.
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 125°C.
5
To enter BDM mode following a POR, BKGD/MS must be held low during the power-up and for a hold time of tMSH after VDD
rises above VLVD.
2
textrst
RESET PIN
Figure A-12. Reset Timing
MC9S08QD4 Series MCU Data Sheet, Rev. 3
188
Freescale Semiconductor
Appendix A Electrical Characteristics
tIHIL
IRQ/KBIPx
IRQ/KBIPx
tILIH
Figure A-13. IRQ/KBIPx Timing
A.8.2
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-9. TPM/MTIM Input Timing
Function
Symbol
Min
Max
Unit
External clock frequency
fTCLK
dc
fBus/4
MHz
External clock period
tTCLK
4
—
tcyc
External clock high time
tclkh
1.5
—
tcyc
External clock low time
tclkl
1.5
—
tcyc
tICPW
1.5
—
tcyc
Input capture pulse width
tText
tclkh
TCLK
tclkl
Figure A-14. Timer External Clock
tICPW
TPMCHn
TPMCHn
tICPW
Figure A-15. Timer Input Capture Pulse
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
189
Appendix A Electrical Characteristics
A.9
ADC Characteristics
Table A-10. ADC Characteristics
Characteristic
Supply Current
ADLPC = 1
ADLSMP = 1
ADCO = 1
Conditions
Symb
VDDAD < 3.6 V (3.0 V Typ)
VDDAD < 5.5 V (5.0 V Typ)
Supply Current
ADLPC = 1
ADLSMP = 0
ADCO = 1
VDDAD < 3.6 V (3.0 V Typ)
Supply Current
ADLPC = 0
ADLSMP = 1
ADCO = 1
VDDAD < 3.6 V (3.0 V Typ)
Supply Current
ADLPC = 0
ADLSMP = 0
ADCO = 1
VDDAD < 3.6V (3.0 V Typ)
Supply Current
Stop, Reset, Module Off
VDDAD < 5.5 V (5.0 V Typ)
VDDAD < 5.5 V (5.0 V Typ)
VDDAD < 5.5V (5.0 V Typ)
IDDAD
IDDAD
IDDAD
IDDAD
IDDAD
Min
Typ1
Max
—
110
—
—
130
—
—
200
—
—
220
—
—
320
—
—
360
—
—
580
—
—
660
—
—
<1
100
nA
Unit
μA
μA
μA
Ref Voltage High
VREFH
2.7
VDDAD
VDDAD
V
VREFL
VSSAD
VSSAD
VSSAD
V
0.4
—
8.0
0.4
—
4.0
High Speed (ADLPC = 0)
ADC Asynchronous
Clock Source
High Speed (ADLPC = 0)
Conversion Time
Short Sample (ADLSMP = 0)
Low Power (ADLPC = 1)
Low Power (ADLPC = 1)
Long Sample (ADLSMP = 1)
Sample Time
Short Sample (ADLSMP = 0)
Long Sample (ADLSMP = 1)
fADCK
fADACK
tADC
tADS
Over
temperature
(Typ 25°C)
μA
Ref Voltage Low
ADC Conversion
Clock
Comment
MHz
tADCK =
1/fADCK
MHz
tADACK =
1/fADACK
2.5
4
6.6
1.25
2
3.3
20
20
23
40
40
43
4
4
4
24
24
24
tADCK
cycles
V
tADCK
cycles
Add 2 to 5
tBus =1/fBus
cycles
Input Voltage
VADIN
VREFL
—
VREFH
Input Capacitance
CADIN
—
7
10
pF
Not Tested
Input Impedance
RADIN
—
5
15
kΩ
Not Tested
RAS
—
—
10(2)
kΩ
External to
MCU
2.637
4.883
5.371
10.547
19.53
21.48
0
±1.5
±3.5
0
±0.7
±1.0
0
±0.5
±1.0
0
±0.3
±0.5
0
±0.5
±1.0
0
±0.3
±0.5
Analog Source
Impedance
Ideal Resolution
(1LSB)
10 bit mode
8 bit mode
Total Unadjusted
Error
10 bit mode
Differential
Non-Linearity
10 bit mode
8 bit mode
8 bit mode
RES
ETUE
DNL
mV
LSB
VREFH/2N
Includes
quantization
LSB
Monotonicity and no-missing-codes guaranteed
Integral
Non-Linearity
10 bit mode
8 bit mode
INL
LSB
MC9S08QD4 Series MCU Data Sheet, Rev. 3
190
Freescale Semiconductor
Appendix A Electrical Characteristics
Table A-10. ADC Characteristics (continued)
Characteristic
Zero-Scale Error
Full-Scale Error
Quantization Error
Conditions
10 bit mode
Symb
EZS
8 bit mode
10 bit mode
EFS
8 bit mode
10 bit mode
EQ
Min
Typ1
Max
0
±1.5
±3.1
0
±0.5
±0.7
0
±1.0
±1.5
0
±0.5
±0.5
—
—
±0.5
Unit
Comment
LSB
VADIN = VSSA
LSB
VADIN = VDDA
LSB
8 bit mode is
not truncated
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
At 4 MHz, for maximum frequency, use proportionally lower source impedance.
A.10
Flash Specifications
This section provides details about program/erase times and program-erase endurance for the flash
memory.
Program and erase operations do not require any special power sources other than the normal VDD supply.
For more detailed information about program/erase operations, see the Memory section.
Table A-11. Flash Characteristics
Characteristic
Symbol
Min
Supply voltage for program/erase
–40°C to 125°C
Vprog/erase
2.7
Supply voltage for read operation
VRead
2.7
5.5
V
Internal FCLK frequency1
fFCLK
150
200
kHz
tFcyc
5
6.67
μs
Internal FCLK period (1/FCLK)
Byte program time (random
location)(2)
Typical
Max
Unit
5.5
V
tprog
9
tFcyc
Byte program time (burst mode)(2)
tBurst
4
tFcyc
Page erase time2
tPage
4000
tFcyc
Mass erase time(2)
tMass
20,000
tFcyc
Program/erase endurance3
TL to TH = –40°C to + 125°C
T = 25°C
Data retention4
tD_ret
10,000
—
100,000
—
—
cycles
15
100
—
years
1
The frequency of this clock is controlled by a software setting.
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.
3 Typical endurance for flash was evaluated for this product family on the 9S12Dx64. For additional information on how
Freescale defines typical endurance, please refer to Engineering Bulletin EB619/D, Typical Endurance for Nonvolatile Memory.
4
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 defines typical data retention, please refer
to Engineering Bulletin EB618/D, Typical Data Retention for Nonvolatile Memory.
2
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
191
Appendix A Electrical Characteristics
MC9S08QD4 Series MCU Data Sheet, Rev. 3
192
Freescale Semiconductor
Appendix B
Ordering Information and Mechanical Drawings
B.1
Ordering Information
This section contains ordering numbers for the devices.
Table B-1. Device Numbering System
Memory
Device Number1
1
B.1.1
•
Available Packages
Qualification
Flash
RAM
Type
Type
MC9S08QD4
MC9S08QD2
4 KB
2 KB
256 B
128 B
8 PDIP
8 NB SOIC
Consumer and Industrial
S9S08QD4
S9S08QD2
4 KB
2 KB
256 B
128 B
8 NB SOIC
Automotive
See Table 1-2 for a complete description of modules included on each device.
Device Numbering Scheme
Numbering Scheme for Consumer and Industrial Products
MC 9 S08 QD 4 X XX
Status
(MC = Fully Qualified)
Memory
(9 = Flash-based)
Core
Package designator (see Table B-2)
Temperature range (M = –40°C to +125°C)
(V = –40°C to +105°C)
(C = –40°C to +85°C)
Family
Approximate memory size (in Kbytes)
Figure 12-7. Numbering Scheme for Consumer and Industrial Products
•
Numbering Scheme for Automotive Products
S 9 S08 QD 4 XX X XX
Status
(S = Fully Qualified)
Memory
(9 = Flash-based)
Core
Family
Package designator (see Table B-2)
Temperature range (M = –40°C to +125°C)
(V = –40°C to +105°C)
(C = –40°C to +85°C)
Fab and Maskset Indicator Suffix
Approximate memory size (in Kbytes)
Figure B-1. Numbering Scheme for Automotive Products
MC9S08QD4 Series MCU Data Sheet, Rev. 3
Freescale Semiconductor
193
Appendix B Ordering Information and Mechanical Drawings
B.2
Mechanical Drawings
The following pages are mechanical specifications for the package options. See Table B-2 for the
document number of each package type.
Table B-2. Package Information
Pin Count
Type
Designator
Document No.
8
PDIP
PC
98ASB42420B
8
NB SOIC
SC
98ASB42564B
MC9S08QD4 Series MCU Data Sheet, Rev. 3
194
Freescale Semiconductor
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MC9S08QD4
Rev. 3, 11/2007
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