ChipFind - документация

Электронный компонент: ST92186B4

Скачать:  PDF   ZIP
September 2003
1/148
.
ST92186B
8/16-BIT MCU FOR TV APPLICATIONS
WITH UP TO 32K ROM AND ENHANCED ON-SCREEN-DISPLAY
s
Register file based 8/16 bit Core Architecture
with RUN, WFI, and HALT modes
s
-10 to 70C Operating Temperature Range
s
24 MHz Operation @5V+-10%
s
Minimum instruction cycle time: 250ns at 16
MHz internal clock, 165ns at 24 MHz internal
clock
s
24 or 32 Kbytes ROM
s
640 bytes of on-chip static RAM
s
256 bytes of Register file
s
256 bytes of display RAM (OSDRAM)
s
32-pin Shrink DIP and 42-pin Shrink DIP
packages
s
26 (SDIP42) or 17 (SDIP32) fully programmable
I/O pins
s
Flexible Clock controller for OSD and Core
clocks, running from one single low frequency
external crystal
s
Enhanced Display Controller with rows of up to
63 characters per row
50/60Hz and 100/120 Hz operation
525/625 lines operation, 4/3 or 16/9 format
Interlaced and progressive scanning
18x26 or 9x13 character matrix
256 (18x26) characters, 1024 (9x13) charac-
ters definable in ROM by user
512 possible colors, in 4x16-entry palettes
2 x 16-entry palettes for Foreground, and 2 x
16-entry palettes for Background
8 levels of translucency on Fast Blanking
Serial, Parallel, and Extended Parallel At-
tributes modes
7 character sizes in 18x26 mode, 4 in 9x13
Rounding, Fringe, Scrolling, Flashing, Shad-
owing, Italics, Semi-transparent
s
5-channel (SDIP42) or 3-channel (SDIP32)
Analog-to-Digital converter with 6-bit accuracy
s
16-bit Watchdog timer with 8-bit prescaler
s
14-bit Voltage Synthesis for tuning reference
voltage with 2 outputs (SDIP42) for 2 tuners or 1
output (SDIP32) for 1 tuner
s
16-bit standard timer with 8-bit prescaler
s
6 (SDIP42) or 4 (SDIP32) 8-bit programmable
PWM outputs
s
NMI and 8 (SDIP42) or 6 (SDIP32) external
interrupts
s
Infra-Red signal digital pre-processor
s
Rich instruction set and 14 addressing modes
s
Versatile Development Tools, including C-
Compiler, Assembler, Linker
s
Source Level Debugger, Emulator and Real-
Time Operating Systems available from third-
parties
s
Windows Based OSD Font and Screen Editor
s
EPROM and OTP devices available
(ST92E196A9 and ST92T196A9)
DEVICE SUMMARY
Device
Program Memory
Package
ST92186B3
24K
SDIP32/SDIP42
ST92186B4
32K
SDIP32/SDIP42
PSDIP32
PSDIP42
2
2/148
Table of Contents
148
1 GENERAL DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.1.1
Core Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.1.2
Instruction Set . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.1.3
Operating Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.1.4
On-chip Peripherals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
1.2 PIN DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
1.2.1
I/O Port Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
1.2.2
I/O Port Reset State . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
1.3 REQUIRED EXTERNAL COMPONENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
1.4 MEMORY MAP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
1.5 INTERRUPT VECTOR TABLE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
1.6 ST92186B REGISTER MAP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
2 DEVICE ARCHITECTURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
2.1 CORE ARCHITECTURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
2.2 MEMORY SPACES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
2.2.1
Register File . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
2.2.2
Register Addressing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
2.3 SYSTEM REGISTERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
2.3.1
Central Interrupt Control Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
2.3.2
Flag Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
2.3.3
Register Pointing Techniques . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
2.3.4
Paged Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
2.3.5
Mode Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
2.3.6
Stack Pointers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
2.4 MEMORY ORGANIZATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
2.5 MEMORY MANAGEMENT UNIT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
2.6 ADDRESS SPACE EXTENSION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
2.6.1
Addressing 16-Kbyte Pages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
2.6.2
Addressing 64-Kbyte Segments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
2.7 MMU REGISTERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
2.7.1
DPR[3:0]: Data Page Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
2.7.2
CSR: Code Segment Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
2.7.3
ISR: Interrupt Segment Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
2.8 MMU USAGE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
2.8.1
Normal Program Execution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
2.8.2
Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
3 INTERRUPTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
3.1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
3.2 INTERRUPT VECTORING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
3.2.1
Divide by Zero trap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
3.2.2
Segment Paging During Interrupt Routines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
3.3 INTERRUPT PRIORITY LEVELS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
3.4 PRIORITY LEVEL ARBITRATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
3.4.1
Priority level 7 (Lowest) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
3/148
Table of Contents
3.4.2
Maximum depth of nesting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
3.4.3
Simultaneous Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
3.4.4
Dynamic Priority Level Modification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
3.5 ARBITRATION MODES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
3.5.1
Concurrent Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
3.5.2
Nested Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
3.6 EXTERNAL INTERRUPTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
3.7 TOP LEVEL INTERRUPT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
3.8 ON-CHIP PERIPHERAL INTERRUPTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
3.9 INTERRUPT RESPONSE TIME . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
3.10 INTERRUPT REGISTERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
4 RESET AND CLOCK CONTROL UNIT (RCCU) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
4.1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
4.2 CLOCK CONTROL REGISTERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
4.3 OSCILLATOR CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
4.3.1
HALT State . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 7
4.4 RESET/STOP MANAGER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
5 TIMING AND CLOCK CONTROLLER (TCC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
5.1 FREQUENCY MULTIPLIERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
5.2 REGISTER DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
6 I/O PORTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
6.1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
6.2 SPECIFIC PORT CONFIGURATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
6.3 PORT CONTROL REGISTERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
6.4 INPUT/OUTPUT BIT CONFIGURATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
6.5 ALTERNATE FUNCTION ARCHITECTURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
6.5.1
Pin Declared as I/O . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
6.5.2
Pin Declared as an Alternate Function Input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
6.5.3
Pin Declared as an Alternate Function Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
6.6 I/O STATUS AFTER WFI, HALT AND RESET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
6.7 CONFIGURATION OF UNBONDED I/OS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
7 ON-CHIP PERIPHERALS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
7.1 TIMER/WATCHDOG (WDT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
7.1.1
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
7.1.2
Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
7.1.3
Watchdog Timer Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
7.1.4
WDT Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
7.1.5
Register Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
7.2 STANDARD TIMER (STIM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
7.2.1
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
7.2.2
Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
7.2.3
Interrupt Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
7.2.4
Register Mapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
7.2.5
Register Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
4/148
Table of Contents
148
7.3 OSDRAM CONTROLLER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
7.3.1
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
7.3.2
Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
7.3.3
OSDRAM Controller Reset Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
7.4 ON SCREEN DISPLAY CONTROLLER (OSD) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
7.4.1
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
7.4.2
General Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
7.4.3
Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
7.4.4
Horizontal and Vertical Sync . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
7.4.5
Programming the Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
7.4.6
Programming the Color Palettes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
7.4.7
Programming the Row Buffers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104
7.4.8
Register Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
7.5 IR PREPROCESSOR (IR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122
7.5.1
Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122
7.5.2
Register Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122
7.6 VOLTAGE SYNTHESIS TUNING CONVERTER (VS) . . . . . . . . . . . . . . . . . . . . . . . . . . 123
7.6.1
Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123
7.6.2
Output Waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123
7.6.3
Register Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127
7.7 PWM GENERATOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128
7.7.1
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128
7.7.2
Register Mapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129
7.8 A/D CONVERTER (A/D) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133
7.8.1
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133
7.8.2
Main Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133
7.8.3
General Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133
7.8.4
Register Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135
8 ELECTRICAL CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137
9 GENERAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144
9.1 PACKAGE MECHANICAL DATA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144
9.2 ORDERING INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145
10 SUMMARY OF CHANGES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147
5/148
ST92186B - GENERAL DESCRIPTION
1 GENERAL DESCRIPTION
1.1 INTRODUCTION
The ST92186B family brings the enhanced ST9
register-based architecture to a new range of high-
performance microcontrollers specifically de-
signed for TV applications. Their performance de-
rives from the use of a flexible 256-register pro-
gramming model for ultra-fast context switching
and real-time event response. The intelligent on-
chip peripherals offload the ST9 core from I/O and
data management processing tasks allowing criti-
cal application tasks to get the maximum use of
core resources. The ST9 MCU devices support
low power consumption and low voltage operation
for power-efficient and low-cost embedded sys-
tems.
1.1.1 Core Architecture
The nucleus of the ST92186B is the enhanced
ST9 Core that includes the Central Processing
Unit (CPU), the register file and the interrupt con-
troller.
Three independent buses are controlled by the
Core: a 16-bit memory bus, an 8-bit register ad-
dressing bus and a 6-bit interrupt bus which con-
nects the interrupt controller in the on-chip periph-
erals with the core.
This multiple bus architecture makes the ST9 fam-
ily devices highly efficient for accessing on and
off-chip memory and fast exchange of data with
the on-chip peripherals.
The general-purpose registers can be used as ac-
cumulators, index registers, or address pointers.
Adjacent register pairs make up 16-bit registers for
addressing or 16-bit processing. Although the ST9
has an 8-bit ALU, the chip handles 16-bit opera-
tions, including arithmetic, loads/stores, and mem-
ory/register and memory/memory exchanges.
Many opcodes specify byte or word operations,
the hardware automatically handles 16-bit opera-
tions and accesses.
For interrupts or subroutine calls, the CPU uses a
system stack in conjunction with the stack pointer
(SP). A separate user stack has its own SP. The
separate stacks, without size limitations, can be in
on-chip RAM (or in Register File) or off-chip mem-
ory.
1.1.2 Instruction Set
The ST9 instruction set consists of 94 instruction
types, including instructions for bit handling, byte
(8-bit) and word (16-bit) data, as well as BCD and
Boolean formats. Instructions have been added to
facilitate large program and data handling through
the MMU, as well as to improve the performance
and code density of C Function calls. 14 address-
ing modes are available, including powerful indi-
rect addressing capabilities.
The ST9's bit-manipulation instructions are set,
clear, complement, test and set, load, and various
logic instructions (AND, OR, and XOR). Math func-
tions include add, subtract, increment, decrement,
decimal adjust, multiply, and divide.
1.1.3 Operating Modes
To optimize performance versus the power con-
sumption of the device, ST9 devices now support
a range of operating modes that can be dynami-
cally selected depending on the performance and
functionality requirements of the application at a
given moment.
Run Mode. This is the full speed execution mode
with CPU and peripherals running at the maximum
clock speed delivered by the Phase Locked Loop
(PLL) of the Clock Control Unit (CCU).
Slow Mode. Power consumption can be signifi-
cantly reduced by running the CPU and the periph-
erals at reduced clock speed using the CPU Pres-
caler and CCU Clock Divider.
Wait For Interrupt Mode. The Wait For Interrupt
(WFI) instruction suspends program execution un-
til an interrupt request is acknowledged. During
WFI, the CPU clock is halted while the peripheral
and interrupt controller keep running at a frequen-
cy programmable via the CCU. In this mode, the
power consumption of the device can be reduced
by more than 95% (LP WFI).
Halt Mode. When executing the HALT instruction,
and if the Watchdog is not enabled, the CPU and
its peripherals stop operating and the status of the
machine remains frozen (the clock is also
stopped). A reset is necessary to exit from Halt
mode.