ST72254G1MB [STMICROELECTRONICS]

8-BIT, FLASH, 8MHz, MICROCONTROLLER, PDSO28, 0.300 INCH, LEAD FREE, PLASTIC, SOIC-28;
ST72254G1MB
型号: ST72254G1MB
厂家: ST    ST
描述:

8-BIT, FLASH, 8MHz, MICROCONTROLLER, PDSO28, 0.300 INCH, LEAD FREE, PLASTIC, SOIC-28

光电二极管
文件: 总135页 (文件大小:3126K)
中文:  中文翻译
下载:  下载PDF数据表文档文件
ST72104Gx-Auto, ST72215Gx-Auto,  
ST72216Gx-Auto, ST72254Gx-Auto  
8-bit MCU for automotive with single voltage Flash/ROM memory,  
ADC, 16-bit timers, SPI, I2C interfaces  
Memories  
– 4K or 8K bytes Program memory (ROM and  
single voltage Flash) with readout protection  
and in-situ programming (remote ISP)  
– 256 bytes RAM  
Clock, Reset and Supply Management  
– Enhanced reset system  
SO28  
– Enhanced low voltage supply supervisor with  
3 programmable levels  
– Clock sources: crystal/ceramic resonator os-  
cillators or RC oscillators, external clock,  
backup Clock Security System  
2 Communications Interfaces  
– Clock-out capability  
– 3 Power Saving Modes: Halt, Wait and Slow  
Interrupt Management  
– 7 interrupt vectors plus TRAP and RESET  
– 22 external interrupt lines (on 2 vectors)  
22 I/O Ports  
– SPI synchronous serial interface  
– I2C multimaster interface  
(only on ST72254Gx-Auto)  
1 Analog Peripheral  
– 8-bit ADC with 6 input channels  
(except on ST72104Gx-Auto)  
– 22 multifunctional bidirectional I/O lines  
– 14 alternate function lines  
– 8 high sink outputs  
Instruction Set  
– 8-bit data manipulation  
– 63 basic instructions  
– 17 main addressing modes  
– 8 x 8 unsigned multiply instruction  
– True bit manipulation  
3 Timers  
– Configurable watchdog timer  
– Two 16-bit timers with: 2 input captures, 2 out-  
put compares, external clock input on one tim-  
er, PWM and Pulse generator modes (one  
only on ST72104Gx-Auto and ST72216G1-  
Auto)  
Development Tools  
– Full hardware/software development package  
Device Summary  
ST72104G1- ST72104G2- ST72216G1- ST72215G2- ST72254G1- ST72254G2-  
Features  
Auto  
Auto  
Auto  
Auto  
Auto  
Auto  
Program memory Flash/ROM 4 Kbytes  
RAM (stack)  
8 Kbytes  
4 Kbytes  
8 Kbytes  
4 Kbytes  
8 Kbytes  
256 (128) bytes  
Watchdog timer  
One 16-bit timer  
Two 16-bit timers  
Peripherals  
SPI  
-
ADC  
I2C  
-
Operating Supply  
CPU Frequency  
Operating Temperature  
Packages  
3.2V to 5.5V  
Up to 8 MHz (with oscillator up to 16 MHz)  
-40°C to +85°C / -40°C to +105°C / -40°C to +125C°  
SO28  
Rev. 1  
October 2007  
1/135  
1
Table of Contents  
1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6  
2 PIN DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7  
3 REGISTER AND MEMORY MAP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10  
4 FLASH PROGRAM MEMORY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13  
4.1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13  
4.2 MAIN FEATURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13  
4.3 STRUCTURAL ORGANIZATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13  
4.4 IN-SITU PROGRAMMING (ISP) MODE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13  
4.5 MEMORY READOUT PROTECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13  
5 CENTRAL PROCESSING UNIT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14  
5.1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14  
5.2 MAIN FEATURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14  
5.3 CPU REGISTERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14  
6 SUPPLY, RESET AND CLOCK MANAGEMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17  
6.1 LOW VOLTAGE DETECTOR (LVD) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18  
6.2 RESET SEQUENCE MANAGER (RSM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19  
6.2.1  
6.2.2  
6.2.3  
6.2.4  
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19  
Asynchronous External RESET pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20  
Internal Low Voltage Detection RESET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20  
Internal Watchdog RESET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20  
6.3 MULTI-OSCILLATOR (MO) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21  
6.4 CLOCK SECURITY SYSTEM (CSS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22  
6.4.1  
6.4.2  
6.4.3  
6.4.4  
Clock Filter Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22  
Safe Oscillator Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22  
Low Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22  
Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22  
6.5 CLOCK RESET AND SUPPLY REGISTER DESCRIPTION (CRSR) . . . . . . . . . . . . . . . 23  
6.6 MAIN CLOCK CONTROLLER (MCC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24  
7 INTERRUPTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25  
7.1 NON-MASKABLE SOFTWARE INTERRUPT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25  
7.2 EXTERNAL INTERRUPTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25  
7.3 PERIPHERAL INTERRUPTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25  
8 POWER SAVING MODES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27  
8.1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27  
8.2 SLOW MODE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27  
8.3 WAIT MODE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28  
8.4 HALT MODE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29  
9 I/O PORTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30  
9.1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30  
9.2 FUNCTIONAL DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30  
9.2.1  
9.2.2  
9.2.3  
Input Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30  
Output Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30  
Alternate Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30  
9.3 I/O PORT IMPLEMENTATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33  
2/135  
2
Table of Contents  
9.4 LOW POWER MODES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34  
9.5 INTERRUPTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34  
9.6 REGISTER DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34  
10 MISCELLANEOUS REGISTERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36  
10.1 I/O PORT INTERRUPT SENSITIVITY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36  
10.2 I/O PORT ALTERNATE FUNCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36  
10.3 MISCELLANEOUS REGISTER DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37  
11 ON-CHIP PERIPHERALS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39  
11.1 WATCHDOG TIMER (WDG) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39  
11.1.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39  
11.1.2 Main Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39  
11.1.3 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39  
11.1.4 Hardware Watchdog Option . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40  
11.1.5 Low Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40  
11.1.6 Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40  
11.1.7 Register Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40  
11.2 16-BIT TIMER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42  
11.2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42  
11.2.2 Main Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42  
11.2.3 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42  
11.2.4 Low Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54  
11.2.5 Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54  
11.2.6 Summary of Timer Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54  
11.2.7 Register Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55  
11.3 SERIAL PERIPHERAL INTERFACE (SPI) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60  
11.3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60  
11.3.2 Main Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60  
11.3.3 General description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60  
11.3.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62  
11.3.5 Low Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69  
11.3.6 Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69  
11.3.7 Register Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70  
11.4 I2C BUS INTERFACE (I2C) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73  
11.4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73  
11.4.2 Main Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73  
11.4.3 General Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73  
11.4.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75  
11.4.5 Low Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79  
11.4.6 Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79  
11.4.7 Register Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80  
11.5 8-BIT A/D CONVERTER (ADC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85  
11.5.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85  
11.5.2 Main Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85  
11.5.3 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85  
11.5.4 Low Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86  
11.5.5 Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86  
11.5.6 Register Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87  
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Table of Contents  
12 INSTRUCTION SET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89  
12.1 ST7 ADDRESSING MODES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89  
12.1.1 Inherent . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90  
12.1.2 Immediate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90  
12.1.3 Direct . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90  
12.1.4 Indexed (No Offset, Short, Long) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90  
12.1.5 Indirect (Short, Long) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90  
12.1.6 Indirect Indexed (Short, Long) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91  
12.1.7 Relative Mode (Direct, Indirect) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91  
12.2 INSTRUCTION GROUPS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92  
13 ELECTRICAL CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95  
13.1 PARAMETER CONDITIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95  
13.1.1 Minimum and Maximum Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95  
13.1.2 Typical Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95  
13.1.3 Typical Curves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95  
13.1.4 Loading Capacitor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95  
13.1.5 Pin Input Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95  
13.2 ABSOLUTE MAXIMUM RATINGS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96  
13.2.1 Voltage Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96  
13.2.2 Current Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96  
13.2.3 Thermal Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96  
13.3 OPERATING CONDITIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97  
13.3.1 General Operating Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97  
13.3.2 Operating Conditions with Low Voltage Detector (LVD) . . . . . . . . . . . . . . . . . . . . 99  
13.4 SUPPLY CURRENT CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101  
13.4.1 RUN and SLOW Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101  
13.4.2 WAIT and SLOW WAIT Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102  
13.4.3 HALT Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103  
13.4.4 Supply and Clock Managers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103  
13.4.5 On-Chip Peripherals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103  
13.5 CLOCK AND TIMING CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104  
13.5.1 General Timings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104  
13.5.2 External Clock Source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104  
13.5.3 Crystal and Ceramic Resonator Oscillators . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105  
13.5.4 RC Oscillators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108  
13.5.5 Clock Security System (CSS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109  
13.6 MEMORY CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110  
13.6.1 RAM and Hardware Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110  
13.6.2 Flash Program Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110  
13.7 EMC CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111  
13.7.1 Functional EMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111  
13.7.2 Absolute Electrical Sensitivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112  
13.7.3 ESD Pin Protection Strategy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114  
13.8 I/O PORT PIN CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116  
13.8.1 General Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116  
13.8.2 Output Driving Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117  
13.9 CONTROL PIN CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119  
4/135  
Table of Contents  
13.9.1 Asynchronous RESET Pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119  
13.9.2 ISPSEL Pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121  
13.10 TIMER PERIPHERAL CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122  
13.10.1 Watchdog Timer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122  
13.10.2 16-Bit Timer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122  
13.11 COMMUNICATION INTERFACE CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . 123  
13.11.1 SPI - Serial Peripheral Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123  
13.11.2 I2C - Inter IC Control Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125  
13.12 8-BIT ADC CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126  
14 PACKAGE CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128  
14.1 PACKAGE MECHANICAL DATA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128  
14.2 ECOPACK® . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128  
14.3 THERMAL CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128  
15 DEVICE CONFIGURATION AND ORDERING INFORMATION . . . . . . . . . . . . . . . . . . . . . . . 129  
15.1 OPTION BYTES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129  
15.2 DEVICE ORDERING INFORMATION AND TRANSFER OF CUSTOMER CODE . . . . 130  
15.3 DEVELOPMENT TOOLS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132  
15.3.1 Package/Socket Footprint Proposal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133  
15.4 ST7 APPLICATION NOTES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133  
16 SUMMARY OF CHANGES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134  
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ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
1 INTRODUCTION  
The  
ST72104G-Auto,  
ST72215G-Auto,  
memory with byte-by-byte In-Situ Programming  
(ISP) capability.  
ST72216G-Auto and ST72254G-Auto devices are  
members of the ST7 microcontroller family. They  
can be grouped as follows:  
Under software control, all devices can be placed  
in WAIT, SLOW, or HALT mode, reducing power  
consumption when the application is in idle or  
standby state.  
– ST72254G-Auto devices are designed for mid-  
range applications with ADC and I²C interface  
capabilities.  
The enhanced instruction set and addressing  
modes of the ST7 offer both power and flexibility to  
software developers, enabling the design of highly  
efficient and compact application code. In addition  
to standard 8-bit data management, all ST7 micro-  
controllers feature true bit manipulation, 8x8 un-  
signed multiplication and indirect addressing  
modes.  
– ST72215/6G-Auto devices target the same  
range of applications but without I²C interface.  
– ST72104G-Auto devices are for applications that  
do not need ADC and I²C peripherals.  
All devices are based on a common industry-  
standard 8-bit core, featuring an enhanced instruc-  
tion set.  
For easy reference, all parametric data are located  
in Section 13 on page 95.  
The ST72C104G, ST72C215G, ST72C216G and  
ST72C254G versions feature single-voltage Flash  
Figure 1. General Block Diagram  
INTERNAL  
CLOCK  
OSC1  
OSC2  
MULTI OSC  
+
CLOCK FILTER  
I2C  
PA7:0  
(8 bits)  
PORT A  
LVD  
VDD  
VSS  
SPI  
POWER  
SUPPLY  
PB7:0  
(8 bits)  
PORT B  
16-BIT TIMER A  
PORT C  
RESET  
CONTROL  
8-BIT CORE  
ALU  
PC5:0  
(6 bits)  
PROGRAM  
MEMORY  
8-BIT ADC  
(4 or 8K bytes)  
16-BIT TIMER B  
RAM  
(256 bytes)  
WATCHDOG  
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4
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
2 PIN DESCRIPTION  
Figure 2. 28-Pin SO Package Pinout  
RESET  
V
V
1
28  
27  
26  
25  
24  
23  
22  
21  
20  
19  
18  
17  
16  
15  
DD  
OSC1  
OSC2  
2
SS  
ISPSEL  
3
SS/PB7  
ISPCLK/SCK/PB6  
ISPDATA/MISO/PB5  
MOSI/PB4  
PA0 (HS)  
4
PA1 (HS)  
5
PA2 (HS)  
6
PA3 (HS)  
7
ei1  
ei0  
OCMP2_A/PB3  
PA4 (HS)/SCLI  
8
ICAP2_A/PB2  
OCMP1_A/PB1  
ICAP1_A/PB0  
9
PA5 (HS)  
PA6 (HS)/SDAI  
PA7 (HS)  
10  
11  
12  
13  
14  
AIN5/EXTCLK_A/PC5  
AIN4/OCMP2_B/PC4  
AIN3/ICAP2_B/PC3  
PC0/ICAP1_B/AIN0  
PC1/OCMP1_B/AIN1  
PC2/MCO/AIN2  
ei0 or ei1  
(HS) 20mA high sink capability  
eiX associated external interrupt vector  
7/135  
5
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
PIN DESCRIPTION (Cont’d)  
For external pin connection guidelines, refer to Section 13 "ELECTRICAL CHARACTERISTICS" on page  
95.  
Legend / Abbreviations for Table 1:  
Type:  
I = input, O = output, S = supply  
A = Dedicated analog input  
Input level:  
In/Output level: C = CMOS 0.3V /0.7V  
,
DD  
DD  
C = CMOS 0.3V /0.7V with input trigger  
T
DD  
DD  
Output level:  
HS = 20mA high sink (on N-buffer only)  
Port and control configuration:  
1)  
– Input:  
float = floating, wpu = weak pull-up, int = interrupt , ana = analog  
2)  
– Output:  
OD = open drain , PP = push-pull  
Refer to Section 9 "I/O PORTS" on page 30 for more details on the software configuration of the I/O ports.  
The RESET configuration of each pin is shown in bold. This configuration is valid as long as the device is  
in reset state.  
Table 1. SO28 Device Pin Description  
Pin  
Level  
Port / Control  
Main  
Function  
(after reset)  
Input  
Output  
Alternate Function  
No.  
Name  
1
2
RESET  
I/O C  
X
X
Top priority non maskable interrupt (active low)  
T
External clock input or Resonator oscillator inverter  
input or resistor input for RC oscillator  
3)  
OSC1  
OSC2  
I
Resonator oscillator inverter output or capacitor in-  
put for RC oscillator  
3)  
3
O
4
5
PB7/SS  
I/O  
I/O  
C
X
X
ei1  
ei1  
X
X
X
X
Port B7  
Port B6  
SPI Slave Select (active low)  
SPI Serial Clock or ISP Clock  
T
T
PB6/SCK/ISPCLK  
C
C
SPI Master In/ Slave Out Data or  
ISP Data  
6
PB5/MISO/ISPDATA I/O  
X
ei1  
X
X
Port B5  
T
7
8
9
PB4/MOSI  
I/O  
I/O  
I/O  
I/O  
I/O  
C
C
C
C
C
X
X
X
X
X
ei1  
ei1  
ei1  
ei1  
ei1  
X
X
X
X
X
X
X
X
X
X
Port B4  
Port B3  
Port B2  
Port B1  
Port B0  
SPI Master Out / Slave In Data  
Timer A Output Compare 2  
Timer A Input Capture 2  
T
T
T
T
T
PB3/OCMP2_A  
PB2/ICAP2_A  
10 PB1 /OCMP1_A  
11 PB0 /ICAP1_A  
Timer A Output Compare 1  
Timer A Input Capture 1  
Timer A Input Clock or ADC Analog  
Input 5  
12 PC5/EXTCLK_A/AIN5 I/O  
13 PC4/OCMP2_B/AIN4 I/O  
14 PC3/ ICAP2_B/AIN3 I/O  
C
C
C
C
C
C
X
X
X
X
X
X
ei0/ei1  
ei0/ei1  
ei0/ei1  
ei0/ei1  
ei0/ei1  
ei0/ei1  
X
X
X
X
X
X
X
X
X
X
X
X
Port C5  
Port C4  
Port C3  
Port C2  
Port C1  
Port C0  
T
T
T
T
T
T
Timer B Output Compare 2 or ADC  
Analog Input 4  
Timer B Input Capture 2 or ADC An-  
alog Input 3  
X
X
X
X
Main clock output (f  
Analog Input 2  
) or ADC  
CPU  
15 PC2/MCO/AIN2  
I/O  
Timer B Output Compare 1 or ADC  
Analog Input 1  
16 PC1/OCMP1_B/AIN1 I/O  
17 PC0/ICAP1_B/AIN0 I/O  
Timer B Input Capture 1 or ADC An-  
alog Input 0  
8/135  
6
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
Pin  
Name  
Level  
Port / Control  
Main  
Function  
(after reset)  
Input  
Output  
Alternate Function  
No.  
18 PA7  
I/O C HS  
X
X
X
X
X
X
X
X
ei0  
X
T
X
T
X
X
X
X
X
X
Port A7  
Port A6  
Port A5  
Port A4  
Port A3  
Port A2  
Port A1  
Port A0  
T
2
19 PA6 /SDAI  
20 PA5  
I/O C HS  
ei0  
ei0  
ei0  
I C Data  
T
I/O C HS  
T
2
21 PA4 /SCLI  
22 PA3  
I/O C HS  
I C Clock  
T
I/O C HS  
ei0  
ei0  
ei0  
ei0  
X
X
X
X
T
23 PA2  
I/O C HS  
T
24 PA1  
I/O C HS  
T
25 PA0  
I/O C HS  
T
In-situ programming selection (should be tied low in  
standard user mode).  
26 ISPSEL  
I
C
X
27  
28  
V
V
S
S
Ground  
SS  
DD  
Main power supply  
Notes:  
1. In the interrupt input column, “eiX” defines the associated external interrupt vector. If the weak pull-up column (wpu) is  
merged with the interrupt column (int), then the I/O configuration is pull-up interrupt input, else the configuration is floating  
interrupt input.  
2. In the open drain output column, “T” defines a true open drain I/O (P-Buffer and protection diode to V are not imple-  
DD  
mented). See Section 9 "I/O PORTS" on page 30 and Section 13.8 "I/O PORT PIN CHARACTERISTICS" on page 116  
for more details.  
3. OSC1 and OSC2 pins connect a crystal or ceramic resonator, an external RC, or an external source to the on-chip  
oscillator see Section 2 "PIN DESCRIPTION" on page 7 and Section 13.5 "CLOCK AND TIMING CHARACTERISTICS"  
on page 104 for more details.  
9/135  
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
3 REGISTER AND MEMORY MAP  
As shown in the Figure 3, the MCU is capable of  
addressing 64 Kbytes of memories and I/O regis-  
ters.  
IMPORTANT: Memory locations marked as “Re-  
served” must never be accessed. Accessing a re-  
served area can have unpredictable effects on the  
device.  
The available memory locations consist of 128  
bytes of register location, 256 bytes of RAM and  
up to 8Kbytes of user program memory. The RAM  
space includes up to 128 bytes for the stack from  
0100h to 017Fh.  
The highest address bytes contain the user reset  
and interrupt vectors.  
Figure 3. Memory Map  
0000h  
HW Registers  
(see Table 2)  
0080h  
Short Addressing RAM  
007Fh  
0080h  
Zero page  
(128 bytes)  
00FFh  
256 bytes RAM  
0100h  
Stack or  
16-bit Addressing RAM  
017Fh  
0180h  
(128 bytes)  
017Fh  
Reserved  
DFFFh  
E000h  
Program Memory  
E000h  
(4K, 8K bytes)  
FFDFh  
8 Kbytes  
F000h  
FFE0h  
Interrupt & Reset Vectors  
4 Kbytes  
FFFFh  
(see Table 5 on page 26)  
FFFFh  
10/135  
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
Table 2. Hardware Register Map  
Register  
Label  
Reset  
Status  
Address  
Block  
Register Name  
Port C Data Register  
Port C Data Direction Register  
Port C Option Register  
Remarks  
1)  
2)  
0000h  
0001h  
0002h  
PCDR  
PCDDR  
PCOR  
00h  
R/W  
2)  
2)  
Port C  
00h  
00h  
R/W  
R/W  
0003h  
Reserved (1 byte)  
1)  
0004h  
0005h  
0006h  
PBDR  
PBDDR  
PBOR  
Port B Data Register  
Port B Data Direction Register  
Port B Option Register  
00h  
R/W  
R/W  
R/W  
Port B  
Port A  
00h  
00h  
0007h  
Reserved (1 byte)  
1)  
0008h  
0009h  
000Ah  
PADR  
PADDR  
PAOR  
Port A Data Register  
Port A Data Direction Register  
Port A Option Register  
00h  
R/W  
R/W  
R/W  
00h  
00h  
000Bh  
to  
Reserved (21 bytes)  
001Fh  
0020h  
MISCR1  
Miscellaneous Register 1  
00h  
R/W  
0021h  
0022h  
0023h  
SPIDR  
SPICR  
SPISR  
SPI Data I/O Register  
SPI Control Register  
SPI Status Register  
xxh  
0xh  
00h  
R/W  
R/W  
Read Only  
SPI  
0024h  
0025h  
WATCHDOG WDGCR  
CRSR  
Watchdog Control Register  
7Fh  
R/W  
Clock, Reset, Supply Control / Status Register 000x 000x R/W  
Reserved (2 bytes)  
0026h  
0027h  
0028h  
0029h  
002Ah  
002Bh  
002Ch  
002Dh  
002Eh  
I2CCR  
I2CSR1  
I2CSR2  
I2CCCR  
I2COAR1  
I2COAR2  
I2CDR  
Control Register  
Status Register 1  
Status Register 2  
Clock Control Register  
Own Address Register 1  
Own Address Register 2  
Data Register  
00h  
00h  
00h  
00h  
00h  
00h  
00h  
R/W  
Read Only  
Read Only  
R/W  
R/W  
R/W  
2
I C  
R/W  
002Fh  
to  
Reserved (2 bytes)  
0030h  
11/135  
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
Register  
Label  
Reset  
Status  
Address  
Block  
Register Name  
Remarks  
R/W  
0031h  
0032h  
0033h  
0034h  
0035h  
0036h  
0037h  
0038h  
0039h  
003Ah  
003Bh  
003Ch  
003Dh  
003Eh  
003Fh  
TACR2  
TACR1  
TASR  
TAIC1HR  
TAIC1LR  
TAOC1HR  
TAOC1LR  
TACHR  
Timer A Control Register 2  
Timer A Control Register 1  
Timer A Status Register  
Timer A Input Capture 1 High Register  
Timer A Input Capture 1 Low Register  
Timer A Output Compare 1 High Register  
Timer A Output Compare 1 Low Register  
Timer A Counter High Register  
00h  
00h  
xxh  
xxh  
xxh  
80h  
00h  
FFh  
FCh  
FFh  
FCh  
xxh  
xxh  
80h  
00h  
R/W  
Read Only  
Read Only  
Read Only  
R/W  
R/W  
TIMER A  
Read Only  
Read Only  
Read Only  
Read Only  
Read Only  
Read Only  
R/W  
TACLR  
Timer A Counter Low Register  
TAACHR  
TAACLR  
TAIC2HR  
TAIC2LR  
TAOC2HR  
TAOC2LR  
Timer A Alternate Counter High Register  
Timer A Alternate Counter Low Register  
Timer A Input Capture 2 High Register  
Timer A Input Capture 2 Low Register  
Timer A Output Compare 2 High Register  
Timer A Output Compare 2 Low Register  
R/W  
0040h  
MISCR2  
Miscellaneous Register 2  
00h  
R/W  
0041h  
0042h  
0043h  
0044h  
0045h  
0046h  
0047h  
0048h  
0049h  
004Ah  
004Bh  
004Ch  
004Dh  
004Eh  
004Fh  
TBCR2  
TBCR1  
TBSR  
TBIC1HR  
TBIC1LR  
TBOC1HR  
TBOC1LR  
TBCHR  
Timer B Control Register 2  
Timer B Control Register 1  
Timer B Status Register  
Timer B Input Capture 1 High Register  
Timer B Input Capture 1 Low Register  
Timer B Output Compare 1 High Register  
Timer B Output Compare 1 Low Register  
Timer B Counter High Register  
00h  
00h  
xxh  
xxh  
xxh  
80h  
00h  
FFh  
FCh  
FFh  
FCh  
xxh  
xxh  
80h  
00h  
R/W  
R/W  
Read Only  
Read Only  
Read Only  
R/W  
R/W  
TIMER B  
Read Only  
Read Only  
Read Only  
Read Only  
Read Only  
Read Only  
R/W  
TBCLR  
Timer B Counter Low Register  
TBACHR  
TBACLR  
TBIC2HR  
TBIC2LR  
TBOC2HR  
TBOC2LR  
Timer B Alternate Counter High Register  
Timer B Alternate Counter Low Register  
Timer B Input Capture 2 High Register  
Timer B Input Capture 2 Low Register  
Timer B Output Compare 2 High Register  
Timer B Output Compare 2 Low Register  
R/W  
0050h  
to  
Reserved (32 bytes)  
006Fh  
0070h  
0071h  
ADCDR  
ADCCSR  
Data Register  
Control/Status Register  
00h  
00h  
Read Only  
R/W  
ADC  
0072h  
to  
Reserved (14 bytes)  
007Fh  
Legend: x=undefined, R/W=read/write  
Notes:  
1. The contents of the I/O port DR registers are readable only in output configuration. In input configuration, the values  
of the I/O pins are returned instead of the DR register contents.  
2. The bits associated with unavailable pins must always keep their reset value.  
12/135  
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
4 FLASH PROGRAM MEMORY  
4.1 INTRODUCTION  
This mode needs five signals (plus the V signal  
if necessary) to be connected to the programming  
tool. This signals are:  
DD  
Flash devices have a single voltage non-volatile  
Flash memory that may be programmed in-situ (or  
plugged in a programming tool) on a byte-by-byte  
basis.  
– RESET: device reset  
– V : device ground power supply  
SS  
– ISPCLK: ISP output serial clock pin  
– ISPDATA: ISP input serial data pin  
4.2 MAIN FEATURES  
– ISPSEL: Remote ISP mode selection. This pin  
must be connected to V on the application  
Remote In-Situ Programming (ISP) mode  
Up to 16 bytes programmed in the same cycle  
MTP memory (Multiple Time Programmable)  
Readout memory protection against piracy  
SS  
board through a pull-down resistor.  
If any of these pins are used for other purposes on  
the application, a serial resistor has to be imple-  
mented to avoid a conflict if the other device forces  
the signal level.  
4.3 STRUCTURAL ORGANIZATION  
Figure 4 shows a typical hardware interface to a  
standard ST7 programming tool. For more details  
on the pin locations, refer to the device pinout de-  
scription.  
The Flash program memory is organized in a sin-  
gle 8-bit wide memory block which can be used for  
storing both code and data constants.  
Figure 4. Typical Remote ISP Interface  
The Flash program memory is mapped in the up-  
per part of the ST7 addressing space and includes  
the reset and interrupt user vector area.  
HE10 CONNECTOR TYPE  
TO PROGRAMMING TOOL  
XTAL  
1
4.4 IN-SITU PROGRAMMING (ISP) MODE  
C
C
L1  
L0  
The Flash program memory can be programmed  
using Remote ISP mode. This ISP mode allows  
the contents of the ST7 program memory to be up-  
dated using a standard ST7 programming tools af-  
ter the device is mounted on the application board.  
This feature can be implemented with a minimum  
number of added components and board area im-  
pact.  
ISPSEL  
10KΩ  
V
SS  
RESET  
ISPCLK  
An example Remote ISP hardware interface to the  
standard ST7 programming tool is described be-  
low. For more details on ISP programming, refer to  
the ST7 Programming Specification.  
ST7  
ISPDATA  
47KΩ  
Remote ISP Overview  
APPLICATION  
The Remote ISP mode is initiated by a specific se-  
quence on the dedicated ISPSEL pin.  
4.5 MEMORY READOUT PROTECTION  
The Remote ISP is performed in three steps:  
– Selection of the RAM execution mode  
– Download of Remote ISP code in RAM  
The readout protection is enabled through an op-  
tion bit.  
For Flash devices, when this option is selected,  
the program and data stored in the Flash memory  
are protected against readout piracy (including a  
re-write protection). When this protection option is  
removed the entire Flash program memory is first  
– Execution of Remote ISP code in RAM to pro-  
gram the user program into the Flash  
Remote ISP hardware configuration  
2
In Remote ISP mode, the ST7 has to be supplied  
automatically erased. However, the E PROM data  
with power (V and V ) and a clock signal (os-  
DD  
SS  
memory (when available) can be protected only  
with ROM devices.  
cillator and application crystal circuit for example).  
13/135  
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
5 CENTRAL PROCESSING UNIT  
5.1 INTRODUCTION  
Accumulator (A)  
The Accumulator is an 8-bit general purpose reg-  
ister used to hold operands and the results of the  
arithmetic and logic calculations and to manipulate  
data.  
This CPU has a full 8-bit architecture and contains  
six internal registers allowing efficient 8-bit data  
manipulation.  
Index Registers (X and Y)  
5.2 MAIN FEATURES  
In indexed addressing modes, these 8-bit registers  
are used to create either effective addresses or  
temporary storage areas for data manipulation.  
(The Cross-Assembler generates a precede in-  
struction (PRE) to indicate that the following in-  
struction refers to the Y register.)  
63 basic instructions  
Fast 8-bit by 8-bit multiply  
17 main addressing modes  
Two 8-bit index registers  
16-bit stack pointer  
Low power modes  
Maskable hardware interrupts  
Non-maskable software interrupt  
The Y register is not affected by the interrupt auto-  
matic procedures (not pushed to and popped from  
the stack).  
Program Counter (PC)  
The program counter is a 16-bit register containing  
the address of the next instruction to be executed  
by the CPU. It is made of two 8-bit registers PCL  
(Program Counter Low which is the LSB) and PCH  
(Program Counter High which is the MSB).  
5.3 CPU REGISTERS  
The six CPU registers shown in Figure 5 are not  
present in the memory mapping and are accessed  
by specific instructions.  
Figure 5. CPU Registers  
7
0
ACCUMULATOR  
RESET VALUE = XXh  
7
0
0
X INDEX REGISTER  
Y INDEX REGISTER  
RESET VALUE = XXh  
7
RESET VALUE = XXh  
PCL  
PCH  
7
8
15  
0
PROGRAM COUNTER  
RESET VALUE = RESET VECTOR @ FFFEh-FFFFh  
7
1
0
H I N Z C  
X 1 X X X  
1
1
1
1
CONDITION CODE REGISTER  
RESET VALUE =  
8
1
15  
7
0
STACK POINTER  
RESET VALUE = STACK HIGHER ADDRESS  
X = Undefined Value  
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ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
CPU REGISTERS (cont’d)  
CONDITION CODE REGISTER (CC)  
Read/Write  
because the I bit is set by hardware at the start of  
the routine and reset by the IRET instruction at the  
end of the routine. If the I bit is cleared by software  
in the interrupt routine, pending interrupts are  
serviced regardless of the priority level of the cur-  
rent interrupt routine.  
Reset Value: 111x1xxx  
7
0
1
1
1
H
I
N
Z
C
Bit 2 = N Negative  
The 8-bit Condition Code register contains the in-  
terrupt mask and four flags representative of the  
result of the instruction just executed. This register  
can also be handled by the PUSH and POP in-  
structions.  
This bit is set and cleared by hardware. It is repre-  
sentative of the result sign of the last arithmetic,  
logical or data manipulation. It is a copy of the 7  
bit of the result.  
0: The result of the last operation is positive or null.  
1: The result of the last operation is negative  
(that is, the most significant bit is a logic 1).  
th  
These bits can be individually tested and/or con-  
trolled by specific instructions.  
This bit is accessed by the JRMI and JRPL instruc-  
tions.  
Bit 4 = H Half carry  
This bit is set by hardware when a carry occurs be-  
tween bits 3 and 4 of the ALU during an ADD or  
ADC instruction. It is reset by hardware during the  
same instructions.  
Bit 1 = Z Zero  
This bit is set and cleared by hardware. This bit in-  
dicates that the result of the last arithmetic, logical  
or data manipulation is zero.  
0: The result of the last operation is different from  
zero.  
1: The result of the last operation is zero.  
0: No half carry has occurred.  
1: A half carry has occurred.  
This bit is tested using the JRH or JRNH instruc-  
tion. The H bit is useful in BCD arithmetic subrou-  
tines.  
This bit is accessed by the JREQ and JRNE test  
instructions.  
Bit 3 = I Interrupt mask  
This bit is set by hardware when entering in inter-  
rupt or by software to disable all interrupts except  
the TRAP software interrupt. This bit is cleared by  
software.  
Bit 0 = C Carry/borrow  
This bit is set and cleared by hardware and soft-  
ware. It indicates an overflow or an underflow has  
occurred during the last arithmetic operation.  
0: No overflow or underflow has occurred.  
1: An overflow or underflow has occurred.  
0: Interrupts are enabled.  
1: Interrupts are disabled.  
This bit is controlled by the RIM, SIM and IRET in-  
structions and is tested by the JRM and JRNM in-  
structions.  
This bit is driven by the SCF and RCF instructions  
and tested by the JRC and JRNC instructions. It is  
also affected by the “bit test and branch”, shift and  
rotate instructions.  
Note: Interrupts requested while I is set are  
latched and can be processed when I is cleared.  
By default an interrupt routine is not interruptible  
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ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
CPU REGISTERS (cont’d)  
Stack Pointer (SP)  
Read/Write  
The least significant byte of the Stack Pointer  
(called S) can be directly accessed by a LD in-  
struction.  
Reset Value: 01 7Fh  
Note: When the lower limit is exceeded, the Stack  
Pointer wraps around to the stack upper limit, with-  
out indicating the stack overflow. The previously  
stored information is then overwritten and there-  
fore lost. The stack also wraps in case of an under-  
flow.  
15  
8
1
0
0
7
0
0
0
0
0
0
0
The stack is used to save the return address dur-  
ing a subroutine call and the CPU context during  
an interrupt. The user may also directly manipulate  
the stack by means of the PUSH and POP instruc-  
tions. In the case of an interrupt, the PCL is stored  
at the first location pointed to by the SP. Then the  
other registers are stored in the next locations as  
shown in Figure 6.  
SP6 SP5 SP4 SP3 SP2 SP1 SP0  
The Stack Pointer is a 16-bit register which is al-  
ways pointing to the next free location in the stack.  
It is then decremented after data has been pushed  
onto the stack and incremented before data is  
popped from the stack (see Figure 6).  
– When an interrupt is received, the SP is decre-  
mented and the context is pushed on the stack.  
Since the stack is 128 bytes deep, the 9 most sig-  
nificant bits are forced by hardware. Following an  
MCU Reset, or after a Reset Stack Pointer instruc-  
tion (RSP), the Stack Pointer contains its reset val-  
ue (the SP6 to SP0 bits are set) which is the stack  
higher address.  
– On return from interrupt, the SP is incremented  
and the context is popped from the stack.  
A subroutine call occupies two locations and an in-  
terrupt five locations in the stack area.  
Figure 6. Stack Manipulation Example  
CALL  
Subroutine  
RET  
or RSP  
PUSH Y  
POP Y  
IRET  
Interrupt  
Event  
@ 0100h  
SP  
SP  
SP  
Y
CC  
A
CC  
A
CC  
A
X
X
X
PCH  
PCL  
PCH  
PCL  
PCH  
PCL  
PCH  
PCL  
PCH  
PCL  
PCH  
PCL  
SP  
SP  
PCH  
PCL  
PCH  
PCL  
SP  
@ 017Fh  
Stack Higher Address = 017Fh  
0100h  
Stack Lower Address =  
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ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
6 SUPPLY, RESET AND CLOCK MANAGEMENT  
The  
ST72104G-Auto,  
ST72215G-Auto,  
ST72216G-Auto and ST72254G-Auto microcon-  
trollers include a range of utility features for secur-  
ing the application in critical situations (for exam-  
ple, in case of a power brown-out), and reducing  
the number of external components. An overview  
is shown in Figure 7.  
See Section 13 "ELECTRICAL CHARACTERIS-  
TICS" on page 95 for more details.  
Main Features  
Supply Manager with main supply low voltage  
detection (LVD)  
Reset Sequence Manager (RSM)  
Multi-Oscillator (MO)  
– 4 Crystal/Ceramic resonator oscillators  
– 1 External RC oscillator  
– 1 Internal RC oscillator  
Clock Security System (CSS)  
– Clock Filter  
– Backup Safe Oscillator  
Figure 7. Clock, Reset and Supply Block Diagram  
MCO  
CLOCK SECURITY SYSTEM  
(CSS)  
MAIN CLOCK  
CONTROLLER  
(MCC)  
MULTI-  
OSCILLATOR  
(MO)  
f
f
CPU  
OSC2  
OSC1  
OSC  
CLOCK  
FILTER  
SAFE  
OSC  
RESET SEQUENCE  
MANAGER  
FROM  
WATCHDOG  
PERIPHERAL  
RESET  
(RSM)  
V
LOW VOLTAGE  
DETECTOR  
(LVD)  
DD  
LVD  
CSS  
IE  
WDG  
RF  
CRSR  
V
0
0
0
RF  
0
D
SS  
CSS INTERRUPT  
17/135  
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
6.1 LOW VOLTAGE DETECTOR (LVD)  
To allow the integration of power management  
features in the application, the Low Voltage Detec-  
tor function (LVD) generates a static reset when  
In these conditions, secure operation is always en-  
sured for the application without the need for ex-  
ternal reset hardware.  
the V  
supply voltage is below a V reference  
DD  
IT-  
During a Low Voltage Detector Reset, the RESET  
pin is held low, thus permitting the MCU to reset  
other devices.  
value. This means that it secures the power-up as  
well as the power-down keeping the ST7 in reset.  
The V reference value for a voltage drop is lower  
IT-  
Notes:  
than the V reference value for power-on in order  
IT+  
1. The LVD allows the device to be used without  
any external RESET circuitry.  
2. Three different reference levels are selectable  
through the option byte according to the applica-  
tion requirement.  
to avoid a parasitic reset when the MCU starts run-  
ning and sinks current on the supply (hysteresis).  
The LVD Reset circuitry generates a reset when  
V
is below:  
DD  
– V when V is rising  
IT+  
DD  
LVD application note  
– V when V is falling  
IT-  
DD  
Application software can detect a reset caused by  
the LVD by reading the LVDRF bit in the CRSR  
register.  
The LVD function is illustrated in the Figure 8.  
Provided the minimum V value (guaranteed for  
DD  
the oscillator frequency) is above V , the MCU  
IT-  
This bit is set by hardware when a LVD reset is  
generated and cleared by software (writing zero).  
can only be in two modes:  
– under full software control  
– in static safe reset  
Figure 8. Low Voltage Detector vs Reset  
V
DD  
V
hyst  
V
V
IT+  
IT-  
RESET  
18/135  
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
6.2 RESET SEQUENCE MANAGER (RSM)  
6.2.1 Introduction  
The 4096 CPU clock cycle delay allows the oscil-  
lator to stabilise and ensures that recovery has  
taken place from the Reset state.  
The reset sequence manager includes three RE-  
SET sources as shown in Figure 10:  
The RESET vector fetch phase duration is 2 clock  
cycles.  
External RESET source pulse  
Internal LVD RESET (Low Voltage Detection)  
Internal WATCHDOG RESET  
Figure 9. RESET Sequence Phases  
These sources act on the RESET pin and it is al-  
ways kept low during the delay phase.  
RESET  
The RESET service routine vector is fixed at ad-  
dresses FFFEh-FFFFh in the ST7 memory map.  
INTERNAL RESET  
4096 CLOCK CYCLES VECTOR  
FETCH  
DELAY  
The basic RESET sequence consists of three  
phases as shown in Figure 9:  
Delay depending on the RESET source  
4096 CPU clock cycle delay  
RESET vector fetch  
Figure 10. Reset Block Diagram  
INTERNAL  
RESET  
V
DD  
f
CPU  
R
ON  
RESET  
WATCHDOG RESET  
LVD RESET  
19/135  
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
RESET SEQUENCE MANAGER (Cont’d)  
6.2.2 Asynchronous External RESET pin  
6.2.3 Internal Low Voltage Detection RESET  
The RESET pin is both an input and an open-drain  
Two different RESET sequences caused by the in-  
ternal LVD circuitry can be distinguished:  
output with integrated R  
weak pull-up resistor.  
ON  
This pull-up has no fixed value but varies in ac-  
cordance with the input voltage. It can be pulled  
low by external circuitry to reset the device. See  
electrical characteristics section for more details.  
Power-On RESET  
Voltage Drop RESET  
The device RESET pin acts as an output that is  
pulled low when V <V  
(rising edge) or  
DD  
IT+  
A RESET signal originating from an external  
V
<V (falling edge) as shown in Figure 11.  
DD  
IT-  
source must have a duration of at least t  
in  
h(RSTL)in  
The LVD filters spikes on V larger than t  
avoid parasitic resets.  
to  
order to be recognized. This detection is asynchro-  
nous and therefore the MCU can enter reset state  
even in HALT mode.  
DD  
g(VDD)  
6.2.4 Internal Watchdog RESET  
The RESET pin is an asynchronous signal which  
plays a major role in EMS performance. In a noisy  
environment, it is recommended to follow the  
guidelines mentioned in the electrical characteris-  
tics section.  
The RESET sequence generated by a internal  
Watchdog counter overflow is shown in Figure 11.  
Starting from the Watchdog counter underflow, the  
device RESET pin acts as an output that is pulled  
low during at least t  
.
w(RSTL)out  
Two RESET sequences can be associated with  
this RESET source: short or long external reset  
pulse (see Figure 11).  
Starting from the external RESET pulse recogni-  
tion, the device RESET pin acts as an output that  
is pulled low during at least t  
.
w(RSTL)out  
Figure 11. RESET Sequences  
V
DD  
V
V
IT+  
IT-  
LVD  
RESET  
SHORT EXT.  
RESET  
LONG EXT.  
RESET  
WATCHDOG  
RESET  
RUN  
RUN  
RUN  
RUN  
RUN  
DELAY  
DELAY  
DELAY  
DELAY  
t
w(RSTL)out  
t
w(RSTL)out  
t
t
h(RSTL)in  
h(RSTL)in  
EXTERNAL  
RESET  
SOURCE  
RESET PIN  
WATCHDOG  
RESET  
WATCHDOG UNDERFLOW  
INTERNAL RESET (4096 TCPU  
FETCH VECTOR  
)
20/135  
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
6.3 MULTI-OSCILLATOR (MO)  
The main clock of the ST7 can be generated by  
four different source types coming from the multi-  
oscillator block:  
tion should not be used in applications that require  
accurate timing.  
In this mode, the two oscillator pins have to be tied  
to ground.  
an external source  
4 crystal or ceramic resonator oscillators  
an external RC oscillator  
an internal high frequency RC oscillator  
Table 3. ST7 Clock Sources  
Hardware Configuration  
Each oscillator is optimized for a given frequency  
range in terms of consumption and is selectable  
through the option byte. The associated hardware  
configuration are shown in Table 3. Refer to the  
electrical characteristics section for more details.  
ST7  
OSC1  
OSC2  
External Clock Source  
EXTERNAL  
SOURCE  
In this external clock mode, a clock signal (square,  
sinus or triangle) with ~50% duty cycle has to drive  
the OSC1 pin while the OSC2 pin is tied to ground.  
Crystal/Ceramic Oscillators  
ST7  
This family of oscillators has the advantage of pro-  
ducing a very accurate rate on the main clock of  
the ST7. The selection within a list of four oscilla-  
tors with different frequency ranges has to be done  
by option byte in order to reduce consumption. In  
this mode of the multi-oscillator, the resonator and  
the load capacitors have to be placed as close as  
possible to the oscillator pins in order to minimize  
output distortion and start-up stabilization time.  
The loading capacitance values must be adjusted  
according to the selected oscillator.  
OSC1  
OSC2  
C
C
L2  
L1  
LOAD  
CAPACITORS  
ST7  
OSC1  
OSC2  
These oscillators are not stopped during the RE-  
SET phase to avoid losing time in the oscillator  
start-up phase.  
External RC Oscillator  
R
C
EX  
EX  
This oscillator allows a low cost solution for the  
main clock of the ST7 using only an external resis-  
tor and an external capacitor. The frequency of the  
external RC oscillator (in the range of some MHz)  
is fixed by the resistor and the capacitor values.  
Consequently in this MO mode, the accuracy of  
ST7  
OSC1  
OSC2  
the clock is dependent on V , T , process varia-  
DD  
A
tions and the accuracy of the discrete components  
used. This option should not be used in applica-  
tions that require accurate timing.  
Internal RC Oscillator  
The internal RC oscillator mode is based on the  
same principle as the external RC oscillator includ-  
ing the resistance and the capacitance of the de-  
vice. This mode is the most cost effective one with  
the drawback of a lower frequency accuracy. Its  
frequency is in the range of several MHz. This op-  
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ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
6.4 CLOCK SECURITY SYSTEM (CSS)  
The Clock Security System (CSS) protects the  
ST7 against main clock problems. To allow the in-  
tegration of the security features in the applica-  
tions, it is based on a clock filter control and an In-  
ternal safe oscillator. The CSS can be enabled or  
disabled by option byte.  
Limitation detection  
The automatic safe oscillator selection is notified  
by hardware setting the CSSD bit of the CRSR  
register. An interrupt can be generated if the CS-  
SIE bit has been previously set.  
These two bits are described in the CRSR register  
description.  
6.4.1 Clock Filter Control  
The clock filter is based on a clock frequency limi-  
tation function.  
6.4.3 Low Power Modes  
Mode  
Description  
This filter function is able to detect and filter high  
frequency spikes on the ST7 main clock.  
No effect on CSS. CSS interrupt cause the  
device to exit from Wait mode.  
WAIT  
If the oscillator is not working properly (e.g. work-  
ing at a harmonic frequency of the resonator), the  
current active oscillator clock can be totally fil-  
tered, and then no clock signal is available for the  
ST7 from this oscillator anymore. If the original  
clock source recovers, the filtering is stopped au-  
tomatically and the oscillator supplies the ST7  
clock.  
The CRSR register is frozen. The CSS (in-  
cluding the safe oscillator) is disabled until  
HALT mode is exited. The previous CSS  
configuration resumes when the MCU is  
woken up by an interrupt with “exit from  
HALT mode” capability or from the counter  
reset value when the MCU is woken up by a  
RESET.  
HALT  
6.4.2 Safe Oscillator Control  
6.4.4 Interrupts  
The safe oscillator of the CSS block is a low fre-  
quency back-up clock source (see Figure 12).  
The CSS interrupt event generates an interrupt if  
the corresponding Enable Control Bit (CSSIE) is  
set and the interrupt mask in the CC register is re-  
set (RIM instruction).  
If the clock signal disappears (due to a broken or  
disconnected resonator...) during a safe oscillator  
period, the safe oscillator delivers a low frequency  
clock signal which allows the ST7 to perform some  
rescue operations.  
Enable Exit  
Control from  
Exit  
Event  
Flag  
Interrupt Event  
from  
1)  
Bit  
Wait Halt  
Automatically, the ST7 clock source switches back  
from the safe oscillator if the original clock source  
recovers.  
CSS event detection  
(safe oscillator acti- CSSD CSSIE  
vated as main clock)  
Yes No  
Notes:  
1. This interrupt allows to exit from Active Halt mode if this  
mode is available in the MCU.  
Figure 12. Clock Filter Function and Safe Oscillator Function  
f
f
/2  
OSC  
CPU  
f
f
/2  
OSC  
SFOSC  
CPU  
f
22/135  
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
6.5 CLOCK RESET AND SUPPLY REGISTER DESCRIPTION (CRSR)  
Read/Write  
Bit 1 = CSSD Clock security system detection  
This bit indicates that the safe oscillator of the  
clock security system block has been selected by  
hardware due to a disturbance on the main clock  
Reset Value: 000x 000x (XXh)  
7
0
signal (f  
). It is set by hardware and cleared by  
OSC  
reading the CRSR register when the original oscil-  
lator recovers.  
LVD  
RF  
CSS CSS WDG  
0
0
0
0
IE  
D
RF  
0: Safe oscillator is not active  
1: Safe oscillator has been activated  
When the CSS is disabled by option byte, the  
CSSD bit value is forced to 0.  
Bit 7:5 = Reserved, always read as 0.  
Bit 4 = LVDRF LVD reset flag  
This bit indicates that the last RESET was gener-  
ated by the LVD block. It is set by hardware (LVD  
reset) and cleared by software (writing zero). See  
WDGRF flag description for more details. When  
the LVD is disabled by option byte, the LVDRF bit  
value is undefined.  
Bit 0 = WDGRF Watchdog reset flag  
This bit indicates that the last RESET was gener-  
ated by the watchdog peripheral. It is set by hard-  
ware (Watchdog RESET) and cleared by software  
(writing zero) or an LVD RESET (to ensure a sta-  
ble cleared state of the WDGRF flag when the  
CPU starts).  
Combined with the LVDRF flag information, the  
flag description is given by the following table.  
Bit 3 = Reserved, always read as 0.  
RESET Sources  
External RESET pin  
LVDRF WDGRF  
Bit 2 = CSSIE Clock security syst interrupt enable  
.
0
0
1
0
1
X
This bit enables the interrupt when a disturbance  
is detected by the clock security system (CSSD bit  
set). It is set and cleared by software.  
Watchdog  
LVD  
0: Clock security system interrupt disabled  
1: Clock security system interrupt enabled  
Refer to Table 5, “Interrupt Mapping,” on page 26  
for more details on the CSS interrupt vector. When  
the CSS is disabled by option byte, the CSSIE bit  
has no effect.  
Application notes  
The LVDRF flag is not cleared when another RE-  
SET type occurs (external or watchdog), the  
LVDRF flag remains set to keep trace of the origi-  
nal failure.  
In this case, a watchdog reset can be detected by  
software while an external reset cannot.  
Table 4. Clock, Reset and Supply Register Map and Reset Values  
Address  
(Hex.)  
Register  
Label  
7
6
5
4
3
2
1
0
CRSR  
Reset Value  
LVDRF  
x
CSSIE  
0
CSSD  
0
WDGRF  
x
0025h  
0
0
0
0
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6.6 MAIN CLOCK CONTROLLER (MCC)  
The Main Clock Controller (MCC) supplies the  
clock for the ST7 CPU and its internal peripherals.  
It allows SLOW power saving mode to be man-  
aged by the application.  
The prescaler allows the selection of the main  
clock frequency and is controlled by three bits of  
the MISCR1: CP1, CP0 and SMS.  
The clock-out capability consists of a dedicated  
All functions are managed by the Miscellaneous  
register 1 (MISCR1).  
I/O port pin configurable as an f  
drive external devices. It is controlled by the MCO  
bit in the MISCR1 register.  
clock output to  
CPU  
The MCC block consists of:  
See Section 10 "MISCELLANEOUS REGIS-  
TERS" on page 36 for more details.  
A programmable CPU clock prescaler  
A clock-out signal to supply external devices  
Figure 13. Main Clock Controller (MCC) Block Diagram  
CLOCK TO CAN  
PERIPHERAL  
PORT  
ALTERNATE  
FUNCTION  
MCO  
fOSC/2  
MISCR1  
-
-
MCO  
-
-
CP1 CP0 SMS  
fOSC  
DIV 2, 4, 8, 16  
DIV 2  
CPU CLOCK  
TO CPU AND  
PERIPHERALS  
fCPU  
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7 INTERRUPTS  
The ST7 core may be interrupted by one of two dif-  
ferent methods: maskable hardware interrupts as  
listed in the Interrupt Mapping Table and a non-  
maskable software interrupt (TRAP). The Interrupt  
processing flowchart is shown in Figure 14.  
It will be serviced according to the flowchart on  
Figure 14.  
7.2 EXTERNAL INTERRUPTS  
External interrupt vectors can be loaded into the  
PC register if the corresponding external interrupt  
occurred and if the I bit is cleared. These interrupts  
allow the processor to leave the Halt low power  
mode.  
The maskable interrupts must be enabled by  
clearing the I bit in order to be serviced. However,  
disabled interrupts may be latched and processed  
when they are enabled (see external interrupts  
subsection).  
The external interrupt polarity is selected through  
the miscellaneous register or interrupt register (if  
available).  
Note: After reset, all interrupts are disabled.  
When an interrupt has to be serviced:  
– Normal processing is suspended at the end of  
the current instruction execution.  
An external interrupt triggered on edge will be  
latched and the interrupt request automatically  
cleared upon entering the interrupt service routine.  
– The PC, X, A and CC registers are saved onto  
the stack.  
If several input pins, connected to the same inter-  
rupt vector, are configured as interrupts, their sig-  
nals are logically NANDed before entering the  
edge/level detection block.  
– The I bit of the CC register is set to prevent addi-  
tional interrupts.  
– The PC is then loaded with the interrupt vector of  
the interrupt to service and the first instruction of  
the interrupt service routine is fetched (refer to  
the Interrupt Mapping Table for vector address-  
es).  
Caution: The type of sensitivity defined in the Mis-  
cellaneous or Interrupt register (if available) ap-  
plies to the ei source. In case of a NANDed source  
(as described on the I/O ports section), a low level  
on an I/O pin configured as input with interrupt,  
masks the interrupt request even in case of rising-  
edge sensitivity.  
The interrupt service routine should finish with the  
IRET instruction which causes the contents of the  
saved registers to be recovered from the stack.  
Note: As a consequence of the IRET instruction,  
the I bit will be cleared and the main program will  
resume.  
7.3 PERIPHERAL INTERRUPTS  
Different peripheral interrupt flags in the status  
register are able to cause an interrupt when they  
are active if both:  
Priority Management  
By default, a servicing interrupt cannot be inter-  
rupted because the I bit is set by hardware enter-  
ing in interrupt routine.  
– The I bit of the CC register is cleared.  
– The corresponding enable bit is set in the control  
register.  
In the case when several interrupts are simultane-  
ously pending, an hardware priority defines which  
one will be serviced first (see the Interrupt Map-  
ping Table).  
If any of these two conditions is false, the interrupt  
is latched and thus remains pending.  
Clearing an interrupt request is done by:  
Interrupts and Low Power Mode  
– Writing “0” to the corresponding bit in the status  
register or  
All interrupts allow the processor to leave the  
WAIT low power mode. Only external and specifi-  
cally mentioned interrupts allow the processor to  
leave the HALT low power mode (refer to the “Exit  
from HALT” column in the Interrupt Mapping Ta-  
ble).  
– Access to the status register while the flag is set  
followed by a read or write of an associated reg-  
ister.  
Note: The clearing sequence resets the internal  
latch. A pending interrupt (that is, waiting to be en-  
abled) will therefore be lost if the clear sequence is  
executed.  
7.1 NON-MASKABLE SOFTWARE INTERRUPT  
This interrupt is entered when the TRAP instruc-  
tion is executed regardless of the state of the I bit.  
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INTERRUPTS (Cont’d)  
Figure 14. Interrupt Processing Flowchart  
FROM RESET  
N
I BIT SET?  
N
Y
INTERRUPT  
PENDING?  
Y
FETCH NEXT INSTRUCTION  
N
IRET?  
STACK PC, X, A, CC  
SET I BIT  
Y
LOAD PC FROM INTERRUPT VECTOR  
EXECUTE INSTRUCTION  
RESTORE PC, X, A, CC FROM STACK  
THIS CLEARS I BIT BY DEFAULT  
Table 5. Interrupt Mapping  
Exit  
from  
HALT  
Source  
Block  
Register Priority  
Address  
Vector  
No.  
Description  
Label  
Order  
RESET  
TRAP  
ei0  
Reset  
yes  
no  
FFFEh-FFFFh  
FFFCh-FFFDh  
FFFAh-FFFBh  
FFF8h-FFF9h  
FFF6h-FFF7h  
FFF4h-FFF5h  
FFF2h-FFF3h  
FFF0h-FFF1h  
FFEEh-FFEFh  
FFECh-FFEDh  
FFEAh-FFEBh  
FFE8h-FFE9h  
FFE6h-FFE7h  
FFE4h-FFE5h  
FFE2h-FFE3h  
FFE0h-FFE1h  
Highest  
Priority  
Software Interrupt  
N/A  
1
0
1
External Interrupt Port A7..0 (C5..0 )  
yes  
1
ei1  
External Interrupt Port B7..0 (C5..0 )  
2
CSS  
Clock Security System Interrupt  
SPI Peripheral Interrupts  
TIMER A Peripheral Interrupts  
Not used  
CRSR  
SPISR  
TASR  
3
SPI  
no  
4
TIMER A  
5
6
TIMER B  
TIMER B Peripheral Interrupts  
Not used  
TBSR  
no  
no  
7
8
Not used  
9
Not used  
10  
11  
12  
13  
Not used  
I²C  
I²C Peripheral Interrupt  
Not Used  
I2CSRx  
Lowest  
Priority  
Not Used  
Notes:  
1. Configurable by option byte.  
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8 POWER SAVING MODES  
8.1 INTRODUCTION  
8.2 SLOW MODE  
To give a large measure of flexibility to the applica-  
tion in terms of power consumption, three main  
power saving modes are implemented in the ST7  
(see Figure 15).  
This mode has two targets:  
– To reduce power consumption by decreasing the  
internal clock in the device,  
– To adapt the internal clock frequency (f  
the available supply voltage.  
) to  
CPU  
After a RESET the normal operating mode is se-  
lected by default (RUN mode). This mode drives  
the device (CPU and embedded peripherals) by  
means of a master clock which is based on the  
SLOW mode is controlled by three bits in the  
MISCR1 register: the SMS bit which enables or  
disables Slow mode and two CPx bits which select  
main oscillator frequency divided by 2 (f  
).  
CPU  
the internal slow frequency (f  
).  
CPU  
From Run mode, the different power saving  
modes may be selected by setting the relevant  
register bits or by calling the specific ST7 software  
instruction whose action depends on the oscillator  
status.  
In this mode, the oscillator frequency can be divid-  
ed by 4, 8, 16 or 32 instead of 2 in normal operat-  
ing mode. The CPU and peripherals are clocked at  
this lower frequency.  
Note: SLOW-WAIT mode is activated when enter-  
ing WAIT mode while the device is already in  
SLOW mode.  
Figure 15. Power Saving Mode Transitions  
High  
RUN  
Figure 16. SLOW Mode Clock Transitions  
f
/4  
f
/8  
f
/2  
OSC  
OSC  
OSC  
f
CPU  
SLOW  
WAIT  
f
/2  
OSC  
00  
01  
CP1:0  
SMS  
SLOW WAIT  
HALT  
NORMAL RUN MODE  
REQUEST  
NEW SLOW  
FREQUENCY  
REQUEST  
Low  
POWER CONSUMPTION  
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POWER SAVING MODES (Cont’d)  
8.3 WAIT MODE  
Figure 17. WAIT Mode Flowchart  
WAIT mode places the MCU in a low power con-  
sumption mode by stopping the CPU.  
OSCILLATOR  
PERIPHERALS  
CPU  
I BIT  
ON  
ON  
OFF  
0
WFI INSTRUCTION  
This power saving mode is selected by calling the  
“WFI” ST7 software instruction.  
All peripherals remain active. During WAIT mode,  
the I bit of the CC register is forced to 0, to enable  
all interrupts. All other registers and memory re-  
main unchanged. The MCU remains in WAIT  
mode until an interrupt or Reset occurs, whereup-  
on the Program Counter branches to the starting  
address of the interrupt or Reset service routine.  
The MCU will remain in WAIT mode until a Reset  
or an Interrupt occurs, causing it to wake up.  
N
RESET  
Y
N
INTERRUPT  
Y
OSCILLATOR  
PERIPHERALS  
CPU  
I BIT  
ON  
OFF  
ON  
1
Refer to Figure 17.  
4096 CPU CLOCK CYCLE  
DELAY  
OSCILLATOR  
PERIPHERALS  
CPU  
ON  
ON  
ON  
1)  
I BIT  
X
FETCH RESET VECTOR  
OR SERVICE INTERRUPT  
Notes:  
1. Before servicing an interrupt, the CC register is pushed  
on the stack. The I bit of the CC register is set during the  
interrupt routine and cleared when the CC register is  
popped.  
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POWER SAVING MODES (Cont’d)  
8.4 HALT MODE  
Figure 19. HALT Mode Flow-chart  
The HALT mode is the lowest power consumption  
mode of the MCU. It is entered by executing the  
ST7 HALT instruction (see Figure 19).  
HALT INSTRUCTION  
ENABLE  
The MCU can exit HALT mode on reception of ei-  
ther a specific interrupt (see Table 5, “Interrupt  
Mapping,” on page 26) or a RESET. When exiting  
HALT mode by means of a RESET or an interrupt,  
the oscillator is immediately turned on and the  
4096 CPU cycle delay is used to stabilize the os-  
cillator. After the start up delay, the CPU resumes  
operation by servicing the interrupt or by fetching  
the reset vector which woke it up (see Figure 18).  
When entering HALT mode, the I bit in the CC reg-  
ister is forced to 0 to enable interrupts. Therefore,  
if an interrupt is pending, the MCU wakes immedi-  
ately.  
WATCHDOG  
0
DISABLE  
WDGHALT 1)  
1
WATCHDOG  
RESET  
OSCILLATOR  
OFF  
PERIPHERALS 2)  
OFF  
OFF  
0
CPU  
I BIT  
N
RESET  
In the HALT mode the main oscillator is turned off  
causing all internal processing to be stopped, in-  
cluding the operation of the on-chip peripherals.  
All peripherals are not clocked except the ones  
which get their clock supply from another clock  
generator (such as an external or auxiliary oscilla-  
tor).  
Y
N
INTERRUPT 3)  
OSCILLATOR  
PERIPHERALS  
CPU  
Y
ON  
OFF  
ON  
1
The compatibility of Watchdog operation with  
HALT mode is configured by the “WDGHALT” op-  
tion bit of the option byte. The HALT instruction  
when executed while the Watchdog system is en-  
abled, can generate a Watchdog RESET (see  
Section 15.1 "OPTION BYTES" on page 129 for  
more details).  
I BIT  
4096 CPU CLOCK CYCLE  
DELAY  
OSCILLATOR  
PERIPHERALS  
CPU  
ON  
ON  
ON  
X 4)  
Figure 18. HALT Mode Timing Overview  
I BIT  
4096 CPU CYCLE  
RUN  
HALT  
RUN  
DELAY  
FETCH RESET VECTOR  
OR SERVICE INTERRUPT  
Notes:  
HALT  
INSTRUCTION  
1. WDGHALT is an option bit. See option byte section for  
more details.  
2. Peripheral clocked with an external clock source can  
still be active.  
3. Only some specific interrupts can exit the MCU from  
HALT mode (such as external interrupt). Refer to Table 5,  
“Interrupt Mapping,” on page 26 for more details.  
4. Before servicing an interrupt, the CC register is pushed  
on the stack. The I bit of the CC register is set during the  
interrupt routine and cleared when the CC register is  
popped.  
RESET  
OR  
INTERRUPT  
FETCH  
VECTOR  
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9 I/O PORTS  
9.1 INTRODUCTION  
programmable using the sensitivity bits in the Mis-  
cellaneous register.  
The I/O ports offer different functional modes:  
– transfer of data through digital inputs and outputs  
Each external interrupt vector is linked to a dedi-  
cated group of I/O port pins (see pinout description  
and interrupt section). If several input pins are se-  
lected simultaneously as interrupt source, these  
are logically NANDed. For this reason if one of the  
interrupt pins is tied low, it masks the other ones.  
and for specific pins:  
– external interrupt generation  
– alternate signal input/output for the on-chip pe-  
ripherals.  
An I/O port contains up to 8 pins. Each pin can be  
programmed independently as digital input (with or  
without interrupt generation) or digital output.  
In case of a floating input with interrupt configura-  
tion, special care must be taken when changing  
the configuration (see Figure 21).  
The external interrupts are hardware interrupts,  
which means that the request latch (not accessible  
directly by the application) is automatically cleared  
when the corresponding interrupt vector is  
fetched. To clear an unwanted pending interrupt  
by software, the sensitivity bits in the Miscellane-  
ous register must be modified.  
9.2 FUNCTIONAL DESCRIPTION  
Each port has two main registers:  
– Data Register (DR)  
– Data Direction Register (DDR)  
and one optional register:  
– Option Register (OR)  
9.2.2 Output Modes  
The output configuration is selected by setting the  
corresponding DDR register bit. In this case, writ-  
ing the DR register applies this digital value to the  
I/O pin through the latch. Then reading the DR reg-  
ister returns the previously stored value.  
Each I/O pin may be programmed using the corre-  
sponding register bits in the DDR and OR regis-  
ters: bit X corresponding to pin X of the port. The  
same correspondence is used for the DR register.  
The following description takes into account the  
OR register, (for specific ports which do not pro-  
vide this register refer to the I/O Port Implementa-  
tion section). The generic I/O block diagram is  
shown in Figure 20.  
Two different output modes can be selected by  
software through the OR register: Output push-pull  
and open-drain.  
DR register value and output pin status:  
9.2.1 Input Modes  
DR  
0
Push-pull  
Open-drain  
V
V
The input configuration is selected by clearing the  
corresponding DDR register bit.  
SS  
SS  
1
V
Floating  
DD  
In this case, reading the DR register returns the  
digital value applied to the external I/O pin.  
9.2.3 Alternate Functions  
When an on-chip peripheral is configured to use a  
pin, the alternate function is automatically select-  
ed. This alternate function takes priority over the  
standard I/O programming.  
Different input modes can be selected by software  
through the OR register.  
Notes:  
1. Writing the DR register modifies the latch value  
but does not affect the pin status.  
When the signal is coming from an on-chip periph-  
eral, the I/O pin is automatically configured in out-  
put mode (push-pull or open drain according to the  
peripheral).  
2. When switching from input to output mode, the  
DR register has to be written first to drive the cor-  
rect level on the pin as soon as the port is config-  
ured as an output.  
When the signal is going to an on-chip peripheral,  
the I/O pin must be configured in input mode. In  
this case, the pin state is also digitally readable by  
addressing the DR register.  
3. Do not use read/modify/write instructions (BSET  
or BRES) to modify the DR register.  
External interrupt function  
When an I/O is configured as Input with Interrupt,  
an event on this I/O can generate an external inter-  
rupt request to the CPU.  
Note: Input pull-up configuration can cause unex-  
pected value at the input of the alternate peripheral  
input. When an on-chip peripheral use a pin as in-  
put and output, this pin has to be configured in in-  
put floating mode.  
Each pin can independently generate an interrupt  
request. The interrupt sensitivity is independently  
30/135  
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
I/O PORTS (Cont’d)  
Figure 20. I/O Port General Block Diagram  
ALTERNATE  
OUTPUT  
1
0
REGISTER  
ACCESS  
P-BUFFER  
(see table below)  
V
DD  
ALTERNATE  
ENABLE  
PULL-UP  
(see table below)  
DR  
DDR  
OR  
V
DD  
PULL-UP  
CONFIGURATION  
PAD  
If implemented  
OR SEL  
DDR SEL  
DR SEL  
N-BUFFER  
DIODES  
(see table below)  
ANALOG  
INPUT  
CMOS  
SCHMITT  
TRIGGER  
1
0
ALTERNATE  
INPUT  
EXTERNAL  
INTERRUPT  
SOURCE (ei )  
FROM  
OTHER  
BITS  
x
POLARITY  
SELECTION  
Table 6. I/O Port Mode Options  
Configuration Mode  
Diodes  
Pull-Up  
P-Buffer  
to V  
to V  
SS  
DD  
Floating with/without Interrupt  
Pull-up with/without Interrupt  
Push-pull  
Off  
On  
Input  
Off  
On  
On  
Off  
On  
Off  
NI  
Output  
Open Drain (logic level)  
True Open Drain  
NI  
NI (see note)  
Legend: NI - not implemented  
Off - implemented not activated  
On - implemented and activated  
Note: The diode to V is not implemented in the  
DD  
true open drain pads. A local protection between  
the pad and V is implemented to protect the de-  
SS  
vice against positive stress.  
31/135  
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
I/O PORTS (Cont’d)  
Table 7. I/O Port Configurations  
Hardware Configuration  
DR REGISTER ACCESS  
NOT IMPLEMENTED IN  
TRUE OPEN DRAIN  
I/O PORTS  
V
DD  
PULL-UP  
CONFIGURATION  
R
W
R
PU  
DR  
REGISTER  
DATA BUS  
PAD  
ALTERNATE INPUT  
FROM  
OTHER  
PINS  
EXTERNAL INTERRUPT  
SOURCE (ei )  
x
INTERRUPT  
CONFIGURATION  
POLARITY  
SELECTION  
ANALOG INPUT  
NOT IMPLEMENTED IN  
TRUE OPEN DRAIN  
I/O PORTS  
DR REGISTER ACCESS  
V
DD  
R
PU  
R/W  
DR  
REGISTER  
DATA BUS  
PAD  
ALTERNATE  
ENABLE  
ALTERNATE  
OUTPUT  
NOT IMPLEMENTED IN  
TRUE OPEN DRAIN  
I/O PORTS  
DR REGISTER ACCESS  
V
DD  
R
PU  
R/W  
DR  
REGISTER  
DATA BUS  
PAD  
ALTERNATE  
ENABLE  
ALTERNATE  
OUTPUT  
Notes:  
1. When the I/O port is in input configuration and the associated alternate function is enabled as an output, reading the  
DR register will read the alternate function output status.  
2. When the I/O port is in output configuration and the associated alternate function is enabled as an input, the alternate  
function reads the pin status given by the DR register content.  
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I/O PORTS (Cont’d)  
Caution: The alternate function must not be acti-  
vated as long as the pin is configured as input with  
interrupt, in order to avoid generating spurious in-  
terrupts.  
Figure 21. Interrupt I/O Port State Transitions  
01  
00  
10  
11  
Analog alternate function  
INPUT  
INPUT  
OUTPUT  
open-drain  
OUTPUT  
push-pull  
floating/pull-up floating  
interrupt (reset state)  
When the pin is used as an ADC input, the I/O  
must be configured as floating input. The analog  
multiplexer (controlled by the ADC registers)  
switches the analog voltage present on the select-  
ed pin to the common analog rail which is connect-  
ed to the ADC input.  
= DDR, OR  
XX  
The I/O port register configurations are summa-  
rized as follows.  
It is recommended not to change the voltage level  
or loading on any port pin while conversion is in  
progress. Furthermore it is recommended not to  
have clocking pins located close to a selected an-  
alog pin.  
Interrupt Ports  
PA7, PA5, PA3:0, PB7:0, PC5:0 (with pull-up)  
MODE  
DDR  
OR  
0
Warning: The analog input voltage level must be  
within the limits stated in the absolute maximum  
ratings.  
floating input  
0
0
1
1
pull-up interrupt input  
open drain output  
push-pull output  
1
0
1
9.3 I/O PORT IMPLEMENTATION  
True Open Drain Interrupt Ports  
The hardware implementation on each I/O port de-  
pends on the settings in the DDR and OR registers  
and specific feature of the I/O port such as ADC In-  
put or true open drain.  
PA6, PA4 (without pull-up)  
MODE  
floating input  
DDR  
OR  
0
0
0
1
Switching these I/O ports from one state to anoth-  
er should be done in a sequence that prevents un-  
wanted side effects. Recommended safe transi-  
tions are illustrated in Figure 21. Other transitions  
are potentially risky and should be avoided, since  
they are likely to present unwanted side-effects  
such as spurious interrupt generation.  
floating interrupt input  
open drain (high sink ports)  
1
X
Table 8. Port Configuration  
Input (DDR = 0)  
Output (DDR = 1)  
Port  
Pin name  
OR = 0  
OR = 1  
OR = 0  
OR = 1  
High-Sink  
PA7  
PA6  
floating  
floating  
floating  
floating  
floating  
floating  
floating  
pull-up interrupt  
floating interrupt  
pull-up interrupt  
floating interrupt  
pull-up interrupt  
pull-up interrupt  
pull-up interrupt  
open drain  
push-pull  
true open-drain  
Port A  
PA5  
open drain  
push-pull  
Yes  
PA4  
true open-drain  
PA3:0  
PB7:0  
PC7:0  
open drain  
open drain  
open drain  
push-pull  
push-pull  
push-pull  
Port B  
Port C  
No  
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I/O PORTS (Cont’d)  
9.4 LOW POWER MODES  
DATA DIRECTION REGISTER (DDR)  
Port x Data Direction Register  
PxDDR with x = A, B or C.  
Mode  
Description  
No effect on I/O ports. External interrupts  
cause the device to exit from WAIT mode.  
WAIT  
Read/Write  
No effect on I/O ports. External interrupts  
cause the device to exit from HALT mode.  
Reset Value: 0000 0000 (00h)  
HALT  
7
0
9.5 INTERRUPTS  
DD7 DD6 DD5 DD4 DD3 DD2 DD1 DD0  
The external interrupt event generates an interrupt  
if the corresponding configuration is selected with  
DDR and OR registers and the I-bit in the CC reg-  
ister is reset (RIM instruction).  
Bit 7:0 = DD[7:0] Data direction register 8 bits.  
The DDR register gives the input/output direction  
configuration of the pins. Each bit is set and  
cleared by software.  
Enable Exit  
Control from  
Exit  
from  
Halt  
Event  
Flag  
Interrupt Event  
Bit  
Wait  
0: Input mode  
1: Output mode  
External interrupt on  
selected external  
event  
DDRx  
ORx  
-
Yes  
Yes  
OPTION REGISTER (OR)  
Port x Option Register  
PxOR with x = A, B or C.  
9.6 REGISTER DESCRIPTION  
DATA REGISTER (DR)  
Read/Write  
Reset Value: 0000 0000 (00h)  
Port x Data Register  
PxDR with x = A, B or C.  
7
0
Read/Write  
Reset Value: 0000 0000 (00h)  
O7  
O6  
O5  
O4  
O3  
O2  
O1  
O0  
7
0
Bit 7:0 = O[7:0] Option register 8 bits.  
For specific I/O pins, this register is not implement-  
ed. In this case the DDR register is enough to se-  
lect the I/O pin configuration.  
D7  
D6  
D5  
D4  
D3  
D2  
D1  
D0  
Bit 7:0 = D[7:0] Data register 8 bits.  
The OR register allows to distinguish: in input  
mode if the pull-up with interrupt capability or the  
basic pull-up configuration is selected, in output  
mode if the push-pull or open drain configuration is  
selected.  
The DR register has a specific behavior according  
to the selected input/output configuration. Writing  
the DR register is always taken into account even  
if the pin is configured as an input; this allows al-  
ways having the expected level on the pin when  
toggling to output mode. Reading the DR register  
returns either the DR register latch content (pin  
configured as output) or the digital value applied to  
the I/O pin (pin configured as input).  
Each bit is set and cleared by software.  
Input mode:  
0: Floating input  
1: Pull-up input with or without interrupt  
Output mode:  
0: Output open drain (with P-Buffer deactivated)  
1: Output push-pull (when available)  
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ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
I/O PORTS (Cont’d)  
Table 9. I/O Port Register Map and Reset Values  
Address (Hex.) Register Label  
7
6
5
4
3
2
1
0
Reset Value of all I/O port registers  
0
0
0
0
0
0
0
0
0000h  
0001h  
0002h  
0004h  
0005h  
0006h  
0008h  
0009h  
000Ah  
PCDR  
PCDDR  
PCOR  
PBDR  
PBDDR  
PBOR  
PADR  
PADDR  
PAOR  
MSB  
MSB  
MSB  
LSB  
LSB  
LSB  
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ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
10 MISCELLANEOUS REGISTERS  
The miscellaneous registers allow control over  
several different features such as the external in-  
terrupts or the I/O alternate functions.  
Figure 22. Ext. Interrupt Sensitivity (EXTIT=0)  
MISCR1  
IS00 IS01  
PA7  
10.1 I/O PORT INTERRUPT SENSITIVITY  
ei0  
INTERRUPT  
SOURCE  
The external interrupt sensitivity is controlled by  
the ISxx bits of the Miscellaneous register and the  
OPTION BYTE. This control allows having two ful-  
ly independent external interrupt source sensitivi-  
ties with configurable sources (using EXTIT option  
bit) as shown in Figure 22 and Figure 23.  
SENSITIVITY  
CONTROL  
PA0  
PC5  
PC0  
MISCR1  
Each external interrupt source can be generated  
on four different events on the pin:  
IS10  
IS11  
ei1  
Falling edge  
Rising edge  
Falling and rising edge  
Falling edge and low level  
PB7  
PB0  
INTERRUPT  
SOURCE  
SENSITIVITY  
CONTROL  
To guarantee correct functionality, the sensitivity  
bits in the MISCR1 register must be modified only  
when the I bit of the CC register is set to 1 (inter-  
rupt masked). See I/O port register and Miscella-  
neous register descriptions for more details on the  
programming.  
Figure 23. Ext. Interrupt Sensitivity (EXTIT=1)  
MISCR1  
IS00  
IS01  
ei0  
PA7  
INTERRUPT  
SOURCE  
SENSITIVITY  
CONTROL  
10.2 I/O PORT ALTERNATE FUNCTIONS  
The MISCR registers manage four I/O port miscel-  
laneous alternate functions:  
PA0  
PB7  
Main clock signal (f  
) output on PC2  
CPU  
MISCR1  
SPI pin configuration:  
IS10  
IS11  
ei1  
– SS pin internal control to use the PB7 I/O port  
INTERRUPT  
SOURCE  
function while the SPI is active.  
SENSITIVITY  
CONTROL  
PB0  
PC5  
– Master output capability on MOSI pin (PB4)  
deactivated while the SPI is active.  
– Slave output capability on MISO pin (PB5) de-  
activated while the SPI is active.  
PC0  
These functions are described in detail in the Sec-  
tion 10.3 "MISCELLANEOUS REGISTER DE-  
SCRIPTION" on page 37.  
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MISCELLANEOUS REGISTERS (Cont’d)  
10.3 MISCELLANEOUS REGISTER DESCRIPTION  
MISCELLANEOUS REGISTER 1 (MISCR1)  
Read/Write  
Bit 2:1 = CP[1:0] CPU clock prescaler  
These bits select the CPU clock prescaler which is  
applied in the different slow modes. Their action is  
conditioned by the setting of the SMS bit. These  
two bits are set and cleared by software  
Reset Value: 0000 0000 (00h)  
7
0
f
in SLOW mode  
CP1  
CP0  
CPU  
f
f
/ 4  
/ 8  
0
1
0
1
0
0
1
1
IS11 IS10 MCO IS01 IS00 CP1 CP0 SMS  
OSC  
OSC  
f
f
/ 16  
/ 32  
OSC  
OSC  
Bit 7:6 = IS1[1:0] ei1 sensitivity  
The interrupt sensitivity, defined using the IS1[1:0]  
bits, is applied to the ei1 external interrupts. These  
two bits can be written only when the I bit of the CC  
register is set to 1 (interrupt masked).  
Bit 0 = SMS Slow mode select  
This bit is set and cleared by software.  
0: Normal mode. f = fOSC / 2  
ei1: Port B (C optional)  
CPU  
1: Slow mode. f  
is given by CP1, CP0  
CPU  
External Interrupt Sensitivity  
Falling edge & low level  
Rising edge only  
IS11 IS10  
See low power consumption mode and MCC  
chapters for more details.  
0
0
1
1
0
1
0
1
Falling edge only  
Rising and falling edge  
Bit 5 = MCO Main clock out selection  
This bit enables the MCO alternate function on the  
PC2 I/O port. It is set and cleared by software.  
0: MCO alternate function disabled (I/O pin free for  
general-purpose I/O)  
1: MCO alternate function enabled (f  
port)  
on I/O  
CPU  
Bit 4:3 = IS0[1:0] ei0 sensitivity  
The interrupt sensitivity, defined using the IS0[1:0]  
bits, is applied to the ei0 external interrupts. These  
two bits can be written only when the I bit of the CC  
register is set to 1 (interrupt masked).  
ei0: Port A (C optional)  
External Interrupt Sensitivity  
Falling edge & low level  
Rising edge only  
IS01 IS00  
0
0
1
1
0
1
0
1
Falling edge only  
Rising and falling edge  
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ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
MISCELLANEOUS REGISTERS (Cont’d)  
MISCELLANEOUS REGISTER 2 (MISCR2)  
Read/Write  
Reset Value: 0000 0000 (00h)  
7
0
0
0
0
0
MOD SOD SSM SSI  
Bit 7:4 = Reserved always read as 0  
Bit 3 = MOD SPI Master Output Disable  
This bit is set and cleared by software. When set, it  
disables the SPI Master (MOSI) output signal.  
0: SPI Master Output enabled.  
1: SPI Master Output disabled.  
Bit 2 = SOD SPI Slave Output Disable  
This bit is set and cleared by software. When set it  
disable the SPI Slave (MISO) output signal.  
0: SPI Slave Output enabled.  
1: SPI Slave Output disabled.  
Bit 1 = SSM SS mode selection  
This bit is set and cleared by software.  
0: Normal mode - the level of the SPI SS signal is  
input from the external SS pin.  
1: I/O mode, the level of the SPI SS signal is read  
from the SSI bit.  
Bit 0 = SSI SS internal mode  
This bit replaces the SS pin of the SPI when the  
SSM bit is set to 1. (see SPI description). It is set  
and cleared by software.  
Table 10. Miscellaneous Register Map and Reset Values  
Address  
(Hex.)  
Register  
Label  
7
6
5
4
3
2
1
0
MISCR1  
Reset Value  
IS11  
0
IS10  
0
MCO  
0
IS01  
0
IS00  
0
CP1  
0
CP0  
0
SMS  
0
0020h  
0040h  
MISCR2  
Reset Value  
MOD  
0
SOD  
0
SSM  
0
SSI  
0
0
0
0
0
38/135  
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
11 ON-CHIP PERIPHERALS  
11.1 WATCHDOG TIMER (WDG)  
11.1.1 Introduction  
11.1.3 Functional Description  
The Watchdog timer is used to detect the occur-  
rence of a software fault, usually generated by ex-  
ternal interference or by unforeseen logical condi-  
tions, which causes the application program to  
abandon its normal sequence. The Watchdog cir-  
cuit generates an MCU reset on expiry of a pro-  
grammed time period, unless the program refresh-  
es the counter’s contents before the T6 bit be-  
comes cleared.  
The counter value stored in the CR register (bits  
T6:T0), is decremented every 12288 machine cy-  
cles, and the length of the timeout period can be  
programmed by the user in 64 increments.  
If the watchdog is activated (the WDGA bit is set)  
and when the 7-bit timer (bits T6:T0) rolls over  
from 40h to 3Fh (T6 becomes cleared), it initiates  
a reset cycle pulling low the RESET pin for typical-  
ly 30µs.  
11.1.2 Main Features  
Programmable timer (64 increments of 12288  
CPU cycles)  
Programmable reset  
The application program must write in the CR reg-  
ister at regular intervals during normal operation to  
prevent an MCU reset. The value to be stored in  
the CR register must be between FFh and C0h  
(see Table 11 Watchdog Timing (fCPU = 8 MHz)):  
Reset (if watchdog activated) when the T6 bit  
– The WDGA bit is set (watchdog enabled)  
reaches zero  
Optional  
reset  
on  
HALT  
instruction  
– The T6 bit is set to prevent generating an imme-  
diate reset  
(configurable by option byte)  
Hardware Watchdog selectable by option byte  
– The T5:T0 bits contain the number of increments  
which represents the time delay before the  
watchdog produces a reset.  
Figure 24. Watchdog Block Diagram  
RESET  
WATCHDOG CONTROL REGISTER (CR)  
T5  
WDGA T6  
T1  
T0  
T4  
T2  
T3  
7-BIT DOWNCOUNTER  
CLOCK DIVIDER  
f
CPU  
÷12288  
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ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
WATCHDOG TIMER (Cont’d)  
Table 11. Watchdog Timing (f  
= 8 MHz)  
– When using an external interrupt to wake up the  
microcontroller, reinitialize the corresponding I/O  
as “Input Pull-up with Interrupt” before executing  
the HALT instruction. The main reason for this is  
that the I/O may be wrongly configured due to ex-  
ternal interference or by an unforeseen logical  
condition.  
CPU  
CR Register  
initial value  
WDG timeout period  
(ms)  
Max  
Min  
FFh  
C0h  
98.304  
1.536  
Notes: Following a reset, the watchdog is disa-  
bled. Once activated it cannot be disabled, except  
by a reset.  
– For the same reason, reinitialize the level sensi-  
tiveness of each external interrupt as a precau-  
tionary measure.  
The T6 bit can be used to generate a software re-  
set (the WDGA bit is set and the T6 bit is cleared).  
– The opcode for the HALT instruction is 0x8E. To  
avoid an unexpected HALT instruction due to a  
program counter failure, it is advised to clear all  
occurrences of the data value 0x8E from memo-  
ry. For example, avoid defining a constant in  
ROM with the value 0x8E.  
11.1.4 Hardware Watchdog Option  
If Hardware Watchdog is selected by option byte,  
the watchdog is always active and the WDGA bit in  
the CR is not used.  
– As the HALT instruction clears the I bit in the CC  
register to allow interrupts, the user may choose  
to clear all pending interrupt bits before execut-  
ing the HALT instruction. This avoids entering  
other peripheral interrupt routines after executing  
the external interrupt routine corresponding to  
the wake-up event (reset or external interrupt).  
Refer to the device-specific Option Byte descrip-  
tion.  
11.1.5 Low Power Modes  
WAIT Instruction  
No effect on Watchdog.  
HALT Instruction  
11.1.6 Interrupts  
If the Watchdog reset on HALT option is selected  
by option byte, a HALT instruction causes an im-  
mediate reset generation if the Watchdog is acti-  
vated (WDGA bit is set).  
None.  
11.1.7 Register Description  
CONTROL REGISTER (CR)  
Read/Write  
11.1.5.1 Using Halt Mode with the WDG (option)  
If the Watchdog reset on HALT option is not se-  
lected by option byte, the Halt mode can be used  
when the watchdog is enabled.  
Reset Value: 0111 1111 (7Fh)  
7
0
In this case, the HALT instruction stops the oscilla-  
tor. When the oscillator is stopped, the WDG stops  
counting and is no longer able to generate a reset  
until the microcontroller receives an external inter-  
rupt or a reset.  
WDGA T6  
T5  
T4  
T3  
T2  
T1  
T0  
Bit 7 = WDGA Activation bit.  
This bit is set by software and only cleared by  
hardware after a reset. When WDGA = 1, the  
watchdog can generate a reset.  
If an external interrupt is received, the WDG re-  
starts counting after 4096 CPU clocks. If a reset is  
generated, the WDG is disabled (reset state).  
0: Watchdog disabled  
1: Watchdog enabled  
Recommendations  
– Make sure that an external event is available to  
wake up the microcontroller from Halt mode.  
Bit 6:0 = T[6:0] 7-bit timer (MSB to LSB).  
These bits contain the decremented value. A reset  
is produced when it rolls over from 40h to 3Fh (T6  
becomes cleared).  
– Before executing the HALT instruction, refresh  
the WDG counter, to avoid an unexpected WDG  
reset immediately after waking up the microcon-  
troller.  
40/135  
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
WATCHDOG TIMER (Cont’d)  
Table 12. Watchdog Timer Register Map and Reset Values  
Address  
(Hex.)  
Register  
Label  
7
6
5
4
3
2
1
0
WDGCR  
Reset Value  
WDGA  
0
T6  
1
T5  
1
T4  
1
T3  
1
T2  
1
T1  
1
T0  
1
0024h  
41/135  
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
11.2 16-BIT TIMER  
11.2.1 Introduction  
When reading an input signal on a non-bonded  
pin, the value will always be ‘1’.  
11.2.3 Functional Description  
11.2.3.1 Counter  
The timer consists of a 16-bit free-running counter  
driven by a programmable prescaler.  
It may be used for a variety of purposes, including  
measuring the pulse lengths of up to two input sig-  
nals (input capture) or generating up to two output  
waveforms (output compare and PWM).  
The main block of the Programmable Timer is a  
16-bit free running upcounter and its associated  
16-bit registers. The 16-bit registers are made up  
of two 8-bit registers called high and low.  
Pulse lengths and waveform periods can be mod-  
ulated from a few microseconds to several milli-  
seconds using the timer prescaler and the CPU  
clock prescaler.  
Counter Register (CR)  
– Counter High Register (CHR) is the most sig-  
nificant byte (MS Byte).  
Some ST7 devices have two on-chip 16-bit timers.  
They are completely independent, and do not  
share any resources. They are synchronized after  
a MCU reset as long as the timer clock frequen-  
cies are not modified.  
– Counter Low Register (CLR) is the least sig-  
nificant byte (LS Byte).  
Alternate Counter Register (ACR)  
– Alternate Counter High Register (ACHR) is  
the most significant byte (MS Byte).  
– Alternate Counter Low Register (ACLR) is the  
least significant byte (LS Byte).  
This description covers one or two 16-bit timers. In  
ST7 devices with two timers, register names are  
prefixed with TA (Timer A) or TB (Timer B).  
11.2.2 Main Features  
These two read-only 16-bit registers contain the  
same value but with the difference that reading the  
ACLR register does not clear the TOF bit (Timer  
overflow flag), located in the Status register (SR).  
(See note at the end of paragraph titled 16-bit read  
sequence).  
Programmable prescaler: f  
divided by 2, 4 or  
CPU  
8.  
Overflow status flag and maskable interrupt  
External clock input (must be at least 4 times  
slowerthantheCPUclockspeed)withthechoice  
of active edge  
Output compare functions with:  
– 2 dedicated 16-bit registers  
– 2 dedicated programmable signals  
– 2 dedicated status flags  
Writing in the CLR register or ACLR register resets  
the free running counter to the FFFCh value.  
Both counters have a reset value of FFFCh (this is  
the only value which is reloaded in the 16-bit tim-  
er). The reset value of both counters is also  
FFFCh in One Pulse mode and PWM mode.  
The timer clock depends on the clock control bits  
of the CR2 register, as illustrated in Table 13 Clock  
Control Bits. The value in the counter register re-  
peats every 131072, 262144 or 524288 CPU clock  
cycles depending on the CC[1:0] bits.  
– 1 dedicated maskable interrupt  
Input capture functions with:  
– 2 dedicated 16-bit registers  
– 2 dedicated active edge selection signals  
– 2 dedicated status flags  
The timer frequency can be f  
or an external frequency.  
/2, f  
/4, f  
/8  
CPU  
CPU  
CPU  
– 1 dedicated maskable interrupt  
Pulse Width Modulation mode (PWM)  
One Pulse mode  
5 alternate functions on I/O ports (ICAP1, ICAP2,  
OCMP1, OCMP2, EXTCLK)*  
The Block Diagram is shown in Figure 25.  
*Note: Some timer pins may not be available (not  
bonded) in some ST7 devices. Refer to the device  
pinout description.  
42/135  
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
16-BIT TIMER (Cont’d)  
Figure 25. Timer Block Diagram  
ST7 INTERNAL BUS  
f
CPU  
MCU-PERIPHERAL INTERFACE  
8 low  
8-bit  
8 high  
8
8
8
8
8
8
8
8
buffer  
EXEDG  
16  
INPUT  
CAPTURE  
REGISTER  
INPUT  
CAPTURE  
REGISTER  
OUTPUT  
COMPARE  
REGISTER  
OUTPUT  
COMPARE  
REGISTER  
1/2  
1/4  
1/8  
COUNTER  
REGISTER  
1
1
2
2
ALTERNATE  
COUNTER  
REGISTER  
EXTCLK  
pin  
16  
16  
16  
CC[1:0]  
TIMER INTERNAL BUS  
16 16  
OVERFLOW  
DETECT  
EDGE DETECT  
CIRCUIT1  
OUTPUT COMPARE  
CIRCUIT  
ICAP1  
pin  
CIRCUIT  
6
EDGE DETECT  
CIRCUIT2  
ICAP2  
pin  
OCMP1  
pin  
LATCH1  
LATCH2  
ICF1 OCF1 TOF ICF2 OCF2  
0
0
0
OCMP2  
pin  
(Status Register) SR  
EXEDG  
ICIE OCIE TOIE FOLV2 FOLV1OLVL2 IEDG1 OLVL1  
OC1E  
OPM PWM CC1 CC0 IEDG2  
OC2E  
(Control Register 1) CR1  
(Control Register 2) CR2  
(See note)  
Note: If IC, OC and TO interrupt requests have separate vectors  
then the last OR is not present (See device Interrupt Vector Table)  
TIMER INTERRUPT  
43/135  
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
16-BIT TIMER (Cont’d)  
16-bit Read Sequence: (from either the Counter  
Register or the Alternate Counter Register).  
Clearing the overflow interrupt request is done in  
two steps:  
1.Reading the SR register while the TOF bit is set.  
2.An access (read or write) to the CLR register.  
Beginning of the sequence  
Read  
MS Byte  
LS Byte  
Note: The TOF bit is not cleared by accessing the  
ACLR register. The advantage of accessing the  
ACLR register rather than the CLR register is that  
it allows simultaneous use of the overflow function  
and reading the free running counter at random  
times (for example, to measure elapsed time) with-  
out the risk of clearing the TOF bit erroneously.  
At t0  
is buffered  
Other  
instructions  
Returns the buffered  
LS Byte value at t0  
Read  
LS Byte  
At t0 +t  
The timer is not affected by WAIT mode.  
Sequence completed  
In HALT mode, the counter stops counting until the  
mode is exited. Counting then resumes from the  
previous count (MCU awakened by an interrupt) or  
from the reset count (MCU awakened by a Reset).  
The user must read the MS Byte first, then the LS  
Byte value is buffered automatically.  
This buffered value remains unchanged until the  
16-bit read sequence is completed, even if the  
user reads the MS Byte several times.  
11.2.3.2 External Clock  
The external clock (where available) is selected if  
CC0 = 1 and CC1 = 1 in the CR2 register.  
After a complete reading sequence, if only the  
CLR register or ACLR register are read, they re-  
turn the LS Byte of the count value at the time of  
the read.  
The status of the EXEDG bit in the CR2 register  
determines the type of level transition on the exter-  
nal clock pin EXTCLK that will trigger the free run-  
ning counter.  
Whatever the timer mode used (input capture, out-  
put compare, One Pulse mode or PWM mode) an  
overflow occurs when the counter rolls over from  
FFFFh to 0000h then:  
The counter is synchronized with the falling edge  
of the internal CPU clock.  
A minimum of four falling edges of the CPU clock  
must occur between two consecutive active edges  
of the external clock; thus the external clock fre-  
quency must be less than a quarter of the CPU  
clock frequency.  
– The TOF bit of the SR register is set.  
– A timer interrupt is generated if:  
– TOIE bit of the CR1 register is set and  
– I bit of the CC register is cleared.  
If one of these conditions is false, the interrupt re-  
mains pending to be issued as soon as they are  
both true.  
44/135  
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
16-BIT TIMER (Cont’d)  
Figure 26. Counter Timing Diagram, internal clock divided by 2  
CPU CLOCK  
INTERNAL RESET  
TIMER CLOCK  
FFFD FFFE FFFF 0000 0001 0002 0003  
COUNTER REGISTER  
TIMER OVERFLOW FLAG (TOF)  
Figure 27. Counter Timing Diagram, internal clock divided by 4  
CPU CLOCK  
INTERNAL RESET  
TIMER CLOCK  
FFFC  
FFFD  
0000  
0001  
COUNTER REGISTER  
TIMER OVERFLOW FLAG (TOF)  
Figure 28. Counter Timing Diagram, internal clock divided by 8  
CPU CLOCK  
INTERNAL RESET  
TIMER CLOCK  
0000  
FFFC  
FFFD  
COUNTER REGISTER  
TIMER OVERFLOW FLAG (TOF)  
Note: The MCU is in reset state when the internal reset signal is high. When it is low, the MCU is running.  
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16-BIT TIMER (Cont’d)  
11.2.3.3 Input Capture  
When an input capture occurs:  
In this section, the index, i, may be 1 or 2 because  
there are two input capture functions in the 16-bit  
timer.  
– The ICFi bit is set.  
– The ICiR register contains the value of the free  
running counter on the active transition on the  
ICAPi pin (see Figure 30).  
The two input capture 16-bit registers (IC1R and  
IC2R) are used to latch the value of the free run-  
ning counter after a transition is detected by the  
ICAPi pin (see Figure 29).  
– A timer interrupt is generated if the ICIE bit is set  
and the I bit is cleared in the CC register. Other-  
wise, the interrupt remains pending until both  
conditions become true.  
MS Byte  
LS Byte  
ICiR  
ICiHR  
ICiLR  
Clearing the Input Capture interrupt request (i.e.  
clearing the ICFi bit) is done in two steps:  
The ICiR register is a read-only register.  
1. Reading the SR register while the ICFi bit is set.  
2. An access (read or write) to the ICiLR register.  
Notes:  
The active transition is software programmable  
through the IEDGi bit of Control Registers (CRi).  
Timing resolution is one count of the free running  
1. After reading the ICiHR register, the transfer of  
input capture data is inhibited and ICFi will  
never be set until the ICiLR register is also  
read.  
counter: (f  
/CC[1:0]).  
CPU  
Procedure:  
To use the input capture function, select the fol-  
lowing in the CR2 register:  
2. The ICiR register contains the free running  
counter value which corresponds to the most  
recent input capture.  
– Select the timer clock (CC[1:0]) (see Table 13  
Clock Control Bits).  
3. The two input capture functions can be used  
together even if the timer also uses the two out-  
put compare functions.  
– Select the edge of the active transition on the  
ICAP2 pin with the IEDG2 bit (the ICAP2 pin  
must be configured as a floating input or input  
with pull-up without interrupt if this configuration  
is available).  
4. In One Pulse mode and PWM mode only the  
input capture 2 function can be used.  
And select the following in the CR1 register:  
5. The alternate inputs (ICAP1 and ICAP2) are  
always directly connected to the timer. So any  
transitions on these pins activate the input cap-  
ture function.  
– Set the ICIE bit to generate an interrupt after an  
input capture coming from either the ICAP1 pin  
or the ICAP2 pin  
Moreover if one of the ICAPi pin is configured  
as an input and the second one as an output,  
an interrupt can be generated if the user tog-  
gles the output pin and if the ICIE bit is set.  
This can be avoided if the input capture func-  
tion i is disabled by reading the ICiHR (see note  
1).  
– Select the edge of the active transition on the  
ICAP1 pin with the IEDG1 bit (the ICAP1 pin  
must be configured as a floating input or input  
with pull-up without interrupt if this configuration  
is available).  
6. The TOF bit can be used with an interrupt in  
order to measure events that exceed the timer  
range (FFFFh).  
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ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
16-BIT TIMER (Cont’d)  
Figure 29. Input Capture Block Diagram  
ICAP1  
pin  
(Control Register 1) CR1  
EDGE DETECT  
CIRCUIT2  
EDGE DETECT  
CIRCUIT1  
ICIE  
IEDG1  
ICAP2  
pin  
(Status Register) SR  
ICF1  
ICF2  
0
0
0
IC2R Register  
IC1R Register  
(Control Register 2) CR2  
16-BIT  
16-BIT FREE RUNNING  
COUNTER  
IEDG2  
CC0  
CC1  
Figure 30. Input Capture Timing Diagram  
TIMER CLOCK  
FF01  
FF02  
FF03  
COUNTER REGISTER  
ICAPi PIN  
ICAPi FLAG  
FF03  
ICAPi REGISTER  
Note: Active edge is rising edge.  
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16-BIT TIMER (Cont’d)  
11.2.3.4 Output Compare  
– The OCMPi pin takes OLVLi bit value (OCMPi  
pin latch is forced low during reset).  
In this section, the index, i, may be 1 or 2 because  
there are 2 output compare functions in the 16-bit  
timer.  
– A timer interrupt is generated if the OCIE bit is  
set in the CR1 register and the I bit is cleared in  
the CC register (CC).  
This function can be used to control an output  
waveform or indicate when a period of time has  
elapsed.  
The OCiR register value required for a specific tim-  
ing application can be calculated using the follow-  
ing formula:  
When a match is found between the Output Com-  
pare register and the free running counter, the out-  
put compare function:  
– Assigns pins with a programmable value if the  
t f  
* CPU  
PRESC  
OCiR =  
OCiE bit is set  
– Sets a flag in the status register  
– Generates an interrupt if enabled  
Where:  
t  
= Output compare period (in seconds)  
= CPU clock frequency (in hertz)  
Two 16-bit registers Output Compare Register 1  
(OC1R) and Output Compare Register 2 (OC2R)  
contain the value to be compared to the counter  
register each timer clock cycle.  
f
CPU  
= Timer prescaler factor (2, 4 or 8 de-  
pending on CC[1:0] bits, see Table 13  
Clock Control Bits)  
PRESC  
MS Byte  
LS Byte  
OCiR  
OCiHR  
OCiLR  
If the timer clock is an external clock, the formula  
is:  
These registers are readable and writable and are  
not affected by the timer hardware. A reset event  
changes the OCiR value to 8000h.  
OCiR = t f  
* EXT  
Timing resolution is one count of the free running  
Where:  
counter: (f  
).  
CC[1:0]  
CPU/  
Procedure:  
t  
= Output compare period (in seconds)  
= External timer clock frequency (in hertz)  
f
EXT  
To use the output compare function, select the fol-  
lowing in the CR2 register:  
Clearing the output compare interrupt request (i.e.  
– Set the OCiE bit if an output is needed then the  
OCMPi pin is dedicated to the output compare i  
signal.  
clearing the OCFi bit) is done by:  
1. Reading the SR register while the OCFi bit is  
set.  
– Select the timer clock (CC[1:0]) (see Table 13  
Clock Control Bits).  
2. An access (read or write) to the OCiLR register.  
And select the following in the CR1 register:  
The following procedure is recommended to pre-  
vent the OCFi bit from being set between the time  
it is read and the write to the OCiR register:  
– Select the OLVLi bit to applied to the OCMPi pins  
after the match occurs.  
– Write to the OCiHR register (further compares  
are inhibited).  
– Set the OCIE bit to generate an interrupt if it is  
needed.  
– Read the SR register (first step of the clearance  
of the OCFi bit, which may be already set).  
When a match is found between OCRi register  
and CR register:  
– Write to the OCiLR register (enables the output  
compare function and clears the OCFi bit).  
– OCFi bit is set.  
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16-BIT TIMER (Cont’d)  
Notes:  
Forced Compare Output capability  
1. After a processor write cycle to the OCiHR reg-  
ister, the output compare function is inhibited  
until the OCiLR register is also written.  
When the FOLVi bit is set by software, the OLVLi  
bit is copied to the OCMPi pin. The OLVi bit has to  
be toggled in order to toggle the OCMPi pin when  
it is enabled (OCiE bit = 1). The OCFi bit is then  
not set by hardware, and thus no interrupt request  
is generated.  
2. If the OCiE bit is not set, the OCMPi pin is a  
general I/O port and the OLVLi bit will not  
appear when a match is found but an interrupt  
could be generated if the OCIE bit is set.  
FOLVLi bits have no effect in either One-Pulse  
mode or PWM mode.  
3. When the timer clock is f  
/2, OCFi and  
CPU  
OCMPi are set while the counter value equals  
the OCiR register value (see Figure 32 on page  
50). This behavior is the same in OPM or PWM  
mode.  
When the timer clock is f  
/4, f  
/8 or in  
CPU  
CPU  
external clock mode, OCFi and OCMPi are set  
while the counter value equals the OCiR regis-  
ter value plus 1 (see Figure 33 on page 50).  
4. The output compare functions can be used both  
for generating external events on the OCMPi  
pins even if the input capture mode is also  
used.  
5. The value in the 16-bit OCiR register and the  
OLVi bit should be changed after each suc-  
cessful comparison in order to control an output  
waveform or establish a new elapsed timeout.  
Figure 31. Output Compare Block Diagram  
16 BIT FREE RUNNING  
OC1E  
CC1 CC0  
OC2E  
COUNTER  
(Control Register 2) CR2  
16-bit  
(Control Register 1) CR1  
OUTPUT COMPARE  
CIRCUIT  
Latch  
1
OCIE  
FOLV2 FOLV1OLVL2  
OLVL1  
OCMP1  
Pin  
16-bit  
16-bit  
Latch  
2
OCMP2  
Pin  
OC1R Register  
OCF1  
OCF2  
0
0
0
OC2R Register  
(Status Register) SR  
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16-BIT TIMER (Cont’d)  
Figure 32. Output Compare Timing Diagram, f  
= f  
/2  
TIMER  
CPU  
INTERNAL CPU CLOCK  
TIMER CLOCK  
COUNTER REGISTER  
2ECF 2ED0 2ED1 2ED2  
2ED3  
2ED4  
2ED3  
OUTPUT COMPARE REGISTER i (OCRi)  
OUTPUT COMPARE FLAG i (OCFi)  
OCMPi PIN (OLVLi = 1)  
Figure 33. Output Compare Timing Diagram, f  
= f  
/4  
TIMER  
CPU  
INTERNAL CPU CLOCK  
TIMER CLOCK  
2ECF 2ED0 2ED1 2ED2  
2ED3  
2ED4  
2ED3  
COUNTER REGISTER  
OUTPUT COMPARE REGISTER i (OCRi)  
COMPARE REGISTER i LATCH  
OUTPUT COMPARE FLAG i (OCFi)  
OCMPi PIN (OLVLi = 1)  
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16-BIT TIMER (Cont’d)  
11.2.3.5 One Pulse Mode  
Clearing the Input Capture interrupt request (i.e.  
clearing the ICFi bit) is done in two steps:  
One Pulse mode enables the generation of a  
pulse when an external event occurs. This mode is  
selected via the OPM bit in the CR2 register.  
1. Reading the SR register while the ICFi bit is set.  
2. An access (read or write) to the ICiLR register.  
The One Pulse mode uses the Input Capture1  
function and the Output Compare1 function.  
The OC1R register value required for a specific  
timing application can be calculated using the fol-  
lowing formula:  
Procedure:  
t * f  
To use One Pulse mode:  
CPU  
- 5  
OCiR Value =  
1. Load the OC1R register with the value corre-  
sponding to the length of the pulse (see the for-  
mula in the opposite column).  
PRESC  
Where:  
t
= Pulse period (in seconds)  
2. Select the following in the CR1 register:  
f
= CPU clock frequency (in hertz)  
CPU  
– Using the OLVL1 bit, select the level to be ap-  
plied to the OCMP1 pin after the pulse.  
= Timer prescaler factor (2, 4 or 8 depend-  
ing on the CC[1:0] bits, see Table 13  
Clock Control Bits)  
PRESC  
– Using the OLVL2 bit, select the level to be ap-  
plied to the OCMP1 pin during the pulse.  
If the timer clock is an external clock the formula is:  
– Select the edge of the active transition on the  
ICAP1 pin with the IEDG1 bit (the ICAP1 pin  
must be configured as floating input).  
OCiR = t f  
-5  
* EXT  
Where:  
t
3. Select the following in the CR2 register:  
= Pulse period (in seconds)  
– Set the OC1E bit, the OCMP1 pin is then ded-  
icated to the Output Compare 1 function.  
f
= External timer clock frequency (in hertz)  
EXT  
– Set the OPM bit.  
When the value of the counter is equal to the value  
of the contents of the OC1R register, the OLVL1  
bit is output on the OCMP1 pin (see Figure 34).  
– Select the timer clock CC[1:0] (see Table 13  
Clock Control Bits).  
Notes:  
One Pulse mode cycle  
1. The OCF1 bit cannot be set by hardware in  
One Pulse mode but the OCF2 bit can generate  
an Output Compare interrupt.  
When  
OCMP1 = OLVL2  
event occurs  
2. When the Pulse Width Modulation (PWM) and  
One Pulse mode (OPM) bits are both set, the  
PWM mode is the only active one.  
on ICAP1  
Counter is reset  
to FFFCh  
ICF1 bit is set  
3. If OLVL1 = OLVL2 a continuous signal will be  
seen on the OCMP1 pin.  
When  
4. The ICAP1 pin cannot be used to perform input  
capture. The ICAP2 pin can be used to perform  
input capture (ICF2 can be set and IC2R can be  
loaded) but the user must take care that the  
counter is reset each time a valid edge occurs  
on the ICAP1 pin and ICF1 can also generates  
interrupt if ICIE is set.  
Counter  
OCMP1 = OLVL1  
= OC1R  
Then, on a valid event on the ICAP1 pin, the coun-  
ter is initialized to FFFCh and the OLVL2 bit is  
loaded on the OCMP1 pin, the ICF1 bit is set and  
the value FFFDh is loaded in the IC1R register.  
5. When One Pulse mode is used OC1R is dedi-  
cated to this mode. Nevertheless OC2R and  
OCF2 can be used to indicate that a period of  
time has elapsed but cannot generate an output  
waveform because the OLVL2 level is dedi-  
cated to One Pulse mode.  
Because the ICF1 bit is set when an active edge  
occurs, an interrupt can be generated if the ICIE  
bit is set.  
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16-BIT TIMER (Cont’d)  
Figure 34. One Pulse Mode Timing Example  
FFFC FFFD FFFE  
2ED0 2ED1 2ED2  
2ED3  
FFFC FFFD  
COUNTER  
ICAP1  
OLVL2  
OLVL1  
OLVL2  
OCMP1  
compare1  
Note: IEDG1 = 1, OC1R = 2ED0h, OLVL1 = 0, OLVL2 = 1  
Figure 35. Pulse Width Modulation Mode Timing Example  
2ED0 2ED1 2ED2  
34E2 FFFC  
FFFC FFFD FFFE  
34E2  
COUNTER  
OCMP1  
OLVL2  
OLVL1  
OLVL2  
compare2  
compare1  
compare2  
Note: OC1R = 2ED0h, OC2R = 34E2, OLVL1 = 0, OLVL2 = 1  
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16-BIT TIMER (Cont’d)  
11.2.3.6 Pulse Width Modulation Mode  
Pulse Width Modulation (PWM) mode enables the  
generation of a signal with a frequency and pulse  
length determined by the value of the OC1R and  
OC2R registers.  
The OCiR register value required for a specific tim-  
ing application can be calculated using the follow-  
ing formula:  
t * f  
CPU  
PRESC  
- 5  
OCiR Value =  
The Pulse Width Modulation mode uses the com-  
plete Output Compare 1 function plus the OC2R  
register, and so these functions cannot be used  
when the PWM mode is activated.  
Where:  
t
= Signal or pulse period (in seconds)  
= CPU clock frequency (in hertz)  
f
Procedure  
CPU  
= Timer prescaler factor (2, 4 or 8 depend-  
ing on CC[1:0] bits, see Table 13 Clock  
Control Bits)  
To use Pulse Width Modulation mode:  
PRESC  
1. Load the OC2R register with the value corre-  
sponding to the period of the signal using the  
formula in the opposite column.  
If the timer clock is an external clock the formula is:  
2. Load the OC1R register with the value corre-  
sponding to the period of the pulse if OLVL1 = 0  
and OLVL2 = 1, using the formula in the oppo-  
site column.  
OCiR = t f  
-5  
* EXT  
Where:  
t
= Signal or pulse period (in seconds)  
3. Select the following in the CR1 register:  
f
= External timer clock frequency (in hertz)  
EXT  
– Using the OLVL1 bit, select the level to be ap-  
plied to the OCMP1 pin after a successful  
comparison with OC1R register.  
The Output Compare 2 event causes the counter  
to be initialized to FFFCh (See Figure 35)  
– Using the OLVL2 bit, select the level to be ap-  
plied to the OCMP1 pin after a successful  
comparison with OC2R register.  
Notes:  
1. After a write instruction to the OCiHR register,  
the output compare function is inhibited until the  
OCiLR register is also written.  
4. Select the following in the CR2 register:  
– Set OC1E bit: the OCMP1 pin is then dedicat-  
ed to the output compare 1 function.  
2. The OCF1 and OCF2 bits cannot be set by  
hardware in PWM mode, therefore the Output  
Compare interrupt is inhibited.  
– Set the PWM bit.  
– Select the timer clock (CC[1:0]) (see Table 13  
Clock Control Bits).  
3. The ICF1 bit is set by hardware when the coun-  
ter reaches the OC2R value and can produce a  
timer interrupt if the ICIE bit is set and the I bit is  
cleared.  
If OLVL1 = 1 and OLVL2 = 0, the length of the  
positive pulse is the difference between the OC2R  
and OC1R registers.  
4. In PWM mode the ICAP1 pin cannot be used to  
perform input capture because it is discon-  
nected from the timer. The ICAP2 pin can be  
used to perform input capture (ICF2 can be set  
and IC2R can be loaded) but the user must  
take care that the counter is reset after each  
period and ICF1 can also generate an interrupt  
if ICIE is set.  
If OLVL1 = OLVL2 a continuous signal will be  
seen on the OCMP1 pin.  
Pulse Width Modulation cycle  
When  
Counter  
= OC1R  
OCMP1 = OLVL1  
5. When the Pulse Width Modulation (PWM) and  
One Pulse mode (OPM) bits are both set, the  
PWM mode is the only active one.  
OCMP1 = OLVL2  
When  
Counter  
= OC2R  
Counter is reset  
to FFFCh  
ICF1 bit is set  
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16-BIT TIMER (Cont’d)  
11.2.4 Low Power Modes  
Mode  
Description  
No effect on 16-bit Timer.  
WAIT  
Timer interrupts cause the device to exit from WAIT mode.  
16-bit Timer registers are frozen.  
In HALT mode, the counter stops counting until Halt mode is exited. Counting resumes from the previous  
count when the MCU is woken up by an interrupt with “exit from HALT mode” capability or from the counter  
reset value when the MCU is woken up by a RESET.  
HALT  
If an input capture event occurs on the ICAPi pin, the input capture detection circuitry is armed. Consequent-  
ly, when the MCU is woken up by an interrupt with “exit from HALT mode” capability, the ICFi bit is set, and  
the counter value present when exiting from HALT mode is captured into the ICiR register.  
11.2.5 Interrupts  
Enable  
Control from  
Bit  
Exit  
Exit  
from  
Halt  
Event  
Flag  
Interrupt Event  
Wait  
Yes  
Yes  
Yes  
Yes  
Yes  
Input Capture 1 event/Counter reset in PWM mode  
Input Capture 2 event  
ICF1  
ICF2  
No  
No  
No  
No  
No  
ICIE  
Output Compare 1 event (not available in PWM mode)  
Output Compare 2 event (not available in PWM mode)  
Timer Overflow event  
OCF1  
OCF2  
TOF  
OCIE  
TOIE  
Note: The 16-bit Timer interrupt events are connected to the same interrupt vector (see Interrupts chap-  
ter). These events generate an interrupt if the corresponding Enable Control Bit is set and the interrupt  
mask in the CC register is reset (RIM instruction).  
11.2.6 Summary of Timer Modes  
AVAILABLE RESOURCES  
MODES  
Input Capture 1  
Input Capture 2  
Output Compare 1 Output Compare 2  
Input Capture (1 and/or 2)  
Output Compare (1 and/or 2)  
One Pulse mode  
Yes  
Yes  
No  
Yes  
Yes  
Yes  
Yes  
No  
Yes  
Yes  
1)  
2)  
Not recommended  
Not recommended  
Partially  
No  
3)  
PWM Mode  
No  
No  
Notes:  
1. See note 4 in Section 11.2.3.5 "One Pulse Mode" on page 51.  
2. See note 5 in Section 11.2.3.5 "One Pulse Mode" on page 51.  
3. See note 4 in Section 11.2.3.6 "Pulse Width Modulation Mode" on page 53.  
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16-BIT TIMER (Cont’d)  
11.2.7 Register Description  
Bit 4 = FOLV2 Forced Output Compare 2.  
This bit is set and cleared by software.  
0: No effect on the OCMP2 pin.  
1:Forces the OLVL2 bit to be copied to the  
OCMP2 pin, if the OC2E bit is set and even if  
there is no successful comparison.  
Each Timer is associated with three control and  
status registers, and with six pairs of data registers  
(16-bit values) relating to the two input captures,  
the two output compares, the counter and the al-  
ternate counter.  
Bit 3 = FOLV1 Forced Output Compare 1.  
This bit is set and cleared by software.  
0: No effect on the OCMP1 pin.  
CONTROL REGISTER 1 (CR1)  
Read/Write  
1: Forces OLVL1 to be copied to the OCMP1 pin, if  
the OC1E bit is set and even if there is no suc-  
cessful comparison.  
Reset Value: 0000 0000 (00h)  
7
0
ICIE OCIE TOIE FOLV2 FOLV1 OLVL2 IEDG1 OLVL1  
Bit 2 = OLVL2 Output Level 2.  
This bit is copied to the OCMP2 pin whenever a  
successful comparison occurs with the OC2R reg-  
ister and OCxE is set in the CR2 register. This val-  
ue is copied to the OCMP1 pin in One Pulse mode  
and Pulse Width Modulation mode.  
Bit 7 = ICIE Input Capture Interrupt Enable.  
0: Interrupt is inhibited.  
1: A timer interrupt is generated whenever the  
ICF1 or ICF2 bit of the SR register is set.  
Bit 1 = IEDG1 Input Edge 1.  
Bit 6 = OCIE Output Compare Interrupt Enable.  
0: Interrupt is inhibited.  
1: A timer interrupt is generated whenever the  
OCF1 or OCF2 bit of the SR register is set.  
This bit determines which type of level transition  
on the ICAP1 pin will trigger the capture.  
0: A falling edge triggers the capture.  
1: A rising edge triggers the capture.  
Bit 5 = TOIE Timer Overflow Interrupt Enable.  
0: Interrupt is inhibited.  
1: A timer interrupt is enabled whenever the TOF  
bit of the SR register is set.  
Bit 0 = OLVL1 Output Level 1.  
The OLVL1 bit is copied to the OCMP1 pin when-  
ever a successful comparison occurs with the  
OC1R register and the OC1E bit is set in the CR2  
register.  
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ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
16-BIT TIMER (Cont’d)  
CONTROL REGISTER 2 (CR2)  
Read/Write  
Bit 4 = PWM Pulse Width Modulation.  
0: PWM mode is not active.  
1: PWM mode is active, the OCMP1 pin outputs a  
programmable cyclic signal; the length of the  
pulse depends on the value of OC1R register;  
the period depends on the value of OC2R regis-  
ter.  
Reset Value: 0000 0000 (00h)  
7
0
OC1E OC2E OPM PWM CC1 CC0 IEDG2 EXEDG  
Bits 3:2 = CC[1:0] Clock Control.  
Bit 7 = OC1E Output Compare 1 Pin Enable.  
This bit is used only to output the signal from the  
timer on the OCMP1 pin (OLV1 in Output Com-  
pare mode, both OLV1 and OLV2 in PWM and  
one-pulse mode). Whatever the value of the OC1E  
bit, the internal Output Compare 1 function of the  
timer remains active.  
0: OCMP1 pin alternate function disabled (I/O pin  
free for general-purpose I/O).  
1: OCMP1 pin alternate function enabled.  
The timer clock mode depends on these bits:  
Table 13. Clock Control Bits  
Timer Clock  
CC1  
CC0  
f
f
f
/ 4  
/ 2  
/ 8  
0
0
1
0
1
0
CPU  
CPU  
CPU  
External Clock (where  
available)  
1
1
Bit 6 = OC2E Output Compare 2 Pin Enable.  
This bit is used only to output the signal from the  
timer on the OCMP2 pin (OLV2 in Output Com-  
pare mode). Whatever the value of the OC2E bit,  
the internal Output Compare 2 function of the timer  
remains active.  
0: OCMP2 pin alternate function disabled (I/O pin  
free for general-purpose I/O).  
1: OCMP2 pin alternate function enabled.  
Note: If the external clock pin is not available, pro-  
gramming the external clock configuration stops  
the counter.  
Bit 1 = IEDG2 Input Edge 2.  
This bit determines which type of level transition  
on the ICAP2 pin will trigger the capture.  
0: A falling edge triggers the capture.  
1: A rising edge triggers the capture.  
Bit 5 = OPM One Pulse mode.  
0: One Pulse mode is not active.  
1: One Pulse mode is active, the ICAP1 pin can be  
used to trigger one pulse on the OCMP1 pin; the  
active transition is given by the IEDG1 bit. The  
length of the generated pulse depends on the  
contents of the OC1R register.  
Bit 0 = EXEDG External Clock Edge.  
This bit determines which type of level transition  
on the external clock pin (EXTCLK) will trigger the  
counter register.  
0: A falling edge triggers the counter register.  
1: A rising edge triggers the counter register.  
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16-BIT TIMER (Cont’d)  
STATUS REGISTER (SR)  
INPUT CAPTURE 1 HIGH REGISTER (IC1HR)  
Read Only  
Read Only  
Reset Value: Undefined  
Reset Value: 0000 0000 (00h)  
This is an 8-bit read only register that contains the  
high part of the counter value (transferred by the  
input capture 1 event).  
The three least significant bits are not used.  
7
0
0
ICF1 OCF1 TOF ICF2 OCF2  
0
0
7
0
MSB  
LSB  
Bit 7 = ICF1 Input Capture Flag 1.  
0: No input capture (reset value).  
1: An input capture has occurred on the ICAP1 pin  
or the counter has reached the OC2R value in  
PWM mode. To clear this bit, first read the SR  
register, then read or write the low byte of the  
IC1R (IC1LR) register.  
INPUT CAPTURE 1 LOW REGISTER (IC1LR)  
Read Only  
Reset Value: Undefined  
This is an 8-bit read only register that contains the  
low part of the counter value (transferred by the in-  
put capture 1 event).  
Bit 6 = OCF1 Output Compare Flag 1.  
0: No match (reset value).  
1: The content of the free running counter matches  
the content of the OC1R register. To clear this  
bit, first read the SR register, then read or write  
the low byte of the OC1R (OC1LR) register.  
7
0
MSB  
LSB  
Bit 5 = TOF Timer Overflow Flag.  
OUTPUT COMPARE  
(OC1HR)  
1
HIGH REGISTER  
0: No timer overflow (reset value).  
1:The free running counter has rolled over from  
FFFFh to 0000h. To clear this bit, first read the  
SR register, then read or write the low byte of  
the CR (CLR) register.  
Read/Write  
Reset Value: 1000 0000 (80h)  
This is an 8-bit register that contains the high part  
of the value to be compared to the CHR register.  
Note: Reading or writing the ACLR register does  
not clear TOF.  
7
0
MSB  
LSB  
Bit 4 = ICF2 Input Capture Flag 2.  
0: No input capture (reset value).  
1: An input capture has occurred on the ICAP2  
pin. To clear this bit, first read the SR register,  
then read or write the low byte of the IC2R  
(IC2LR) register.  
OUTPUT COMPARE  
(OC1LR)  
1
LOW REGISTER  
Read/Write  
Reset Value: 0000 0000 (00h)  
Bit 3 = OCF2 Output Compare Flag 2.  
0: No match (reset value).  
This is an 8-bit register that contains the low part of  
the value to be compared to the CLR register.  
1: The content of the free running counter matches  
the content of the OC2R register. To clear this  
bit, first read the SR register, then read or write  
the low byte of the OC2R (OC2LR) register.  
7
0
MSB  
LSB  
Bit 2:0 = Reserved, forced by hardware to 0.  
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ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
16-BIT TIMER (Cont’d)  
OUTPUT COMPARE  
(OC2HR)  
2
HIGH REGISTER  
ALTERNATE COUNTER HIGH REGISTER  
(ACHR)  
Read/Write  
Reset Value: 1000 0000 (80h)  
Read Only  
Reset Value: 1111 1111 (FFh)  
This is an 8-bit register that contains the high part  
of the value to be compared to the CHR register.  
This is an 8-bit register that contains the high part  
of the counter value.  
7
0
7
0
MSB  
LSB  
MSB  
LSB  
OUTPUT COMPARE  
(OC2LR)  
2
LOW REGISTER  
ALTERNATE COUNTER LOW REGISTER  
(ACLR)  
Read/Write  
Reset Value: 0000 0000 (00h)  
Read Only  
Reset Value: 1111 1100 (FCh)  
This is an 8-bit register that contains the low part of  
the value to be compared to the CLR register.  
This is an 8-bit register that contains the low part of  
the counter value. A write to this register resets the  
counter. An access to this register after an access  
to SR register does not clear the TOF bit in SR  
register.  
7
0
MSB  
LSB  
7
0
COUNTER HIGH REGISTER (CHR)  
MSB  
LSB  
Read Only  
Reset Value: 1111 1111 (FFh)  
INPUT CAPTURE 2 HIGH REGISTER (IC2HR)  
This is an 8-bit register that contains the high part  
of the counter value.  
Read Only  
Reset Value: Undefined  
7
0
This is an 8-bit read only register that contains the  
high part of the counter value (transferred by the  
Input Capture 2 event).  
MSB  
LSB  
7
0
MSB  
LSB  
COUNTER LOW REGISTER (CLR)  
Read Only  
Reset Value: 1111 1100 (FCh)  
This is an 8-bit register that contains the low part of  
the counter value. A write to this register resets the  
counter. An access to this register after accessing  
the SR register clears the TOF bit.  
INPUT CAPTURE 2 LOW REGISTER (IC2LR)  
Read Only  
Reset Value: Undefined  
This is an 8-bit read only register that contains the  
low part of the counter value (transferred by the In-  
put Capture 2 event).  
7
0
MSB  
LSB  
7
0
MSB  
LSB  
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16-BIT TIMER (Cont’d)  
Table 14. 16-Bit Timer Register Map and Reset Values  
Address  
(Hex.)  
Register  
Label  
7
6
5
4
3
2
1
0
Timer A: 32 CR1  
ICIE  
0
OCIE  
0
TOIE  
0
FOLV2  
0
FOLV1  
0
OLVL2  
0
IEDG1  
0
OLVL1  
0
Timer B: 42 Reset Value  
Timer A: 31 CR2  
OC1E  
0
OC2E  
0
OPM  
0
PWM  
0
CC1  
0
CC0  
0
IEDG2  
0
EXEDG  
0
Timer B: 41 Reset Value  
Timer A: 33 SR  
ICF1  
0
OCF1  
0
TOF  
0
ICF2  
0
OCF2  
0
-
-
-
Timer B: 43 Reset Value  
0
0
0
Timer A: 34 ICHR1  
MSB  
-
LSB  
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Timer B: 44 Reset Value  
Timer A: 35 ICLR1  
MSB  
-
LSB  
-
Timer B: 45 Reset Value  
Timer A: 36 OCHR1  
MSB  
-
LSB  
-
Timer B: 46 Reset Value  
Timer A: 37 OCLR1  
MSB  
-
LSB  
-
Timer B: 47 Reset Value  
Timer A: 3E OCHR2  
MSB  
-
LSB  
-
Timer B: 4E Reset Value  
Timer A: 3F OCLR2  
MSB  
-
LSB  
-
Timer B: 4F Reset Value  
Timer A: 38 CHR  
MSB  
1
LSB  
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
0
1
Timer B: 48 Reset Value  
Timer A: 39 CLR  
MSB  
1
LSB  
0
Timer B: 49 Reset Value  
Timer A: 3A ACHR  
MSB  
1
LSB  
1
Timer B: 4A Reset Value  
Timer A: 3B ACLR  
MSB  
1
LSB  
0
1
-
1
-
1
-
1
-
1
-
0
-
Timer B: 4B Reset Value  
Timer A: 3C ICHR2  
MSB  
-
LSB  
-
Timer B: 4C Reset Value  
Timer A: 3D ICLR2  
MSB  
-
LSB  
-
-
-
-
-
-
-
Timer B: 4D Reset Value  
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11.3 SERIAL PERIPHERAL INTERFACE (SPI)  
11.3.1 Introduction  
11.3.3 General description  
The Serial Peripheral Interface (SPI) allows full-  
duplex, synchronous, serial communication with  
external devices. An SPI system may consist of a  
master and one or more slaves or a system in  
which devices may be either masters or slaves.  
The SPI is connected to external devices through  
four alternate pins:  
– MISO: Master In Slave Out pin  
– MOSI: Master Out Slave In pin  
– SCK: Serial Clock pin  
The SPI is normally used for communication be-  
tween the microcontroller and external peripherals  
or another microcontroller.  
– SS: Slave select pin  
A basic example of interconnections between a  
single master and a single slave is illustrated on  
Figure 36.  
Refer to the Pin Description chapter for the device-  
specific pinout.  
11.3.2 Main Features  
Full duplex, three-wire synchronous transfers  
Master or slave operation  
4 master mode frequencies  
Maximum slave mode frequency = f  
4 programmable master bit rates  
Programmable clock polarity and phase  
End of transfer interrupt flag  
Write collision flag protection  
The MOSI pins are connected together as are  
MISO pins. In this way data is transferred serially  
between master and slave (most significant bit  
first).  
When the master device transmits data to a slave  
device via MOSI pin, the slave device responds by  
sending data to the master device via the MISO  
pin. This implies full duplex transmission with both  
data out and data in synchronized with the same  
clock signal (which is provided by the master de-  
vice via the SCK pin).  
/4  
CPU  
Master mode fault protection capability  
Thus, the byte transmitted is replaced by the byte  
received and eliminates the need for separate  
transmit-empty and receiver-full bits. A status flag  
is used to indicate that the I/O operation is com-  
plete.  
Four possible data/clock timing relationships may  
be chosen (see Figure 39) but master and slave  
must be programmed with the same timing mode.  
Figure 36. Serial Peripheral Interface Master/Slave  
MASTER  
SLAVE  
MSBit  
LSBit  
MSBit  
LSBit  
MISO  
MOSI  
MISO  
MOSI  
8-BIT SHIFT REGISTER  
8-BIT SHIFT REGISTER  
SPI  
CLOCK  
GENERATOR  
SCK  
SS  
SCK  
SS  
+5V  
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ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
SERIAL PERIPHERAL INTERFACE (Cont’d)  
Figure 37. Serial Peripheral Interface Block Diagram  
Internal Bus  
Read  
DR  
Read Buffer  
IT  
request  
MOSI  
SR  
MISO  
8-Bit Shift Register  
Write  
MODF  
WCOL  
SPIF  
-
-
-
-
-
SPI  
STATE  
CONTROL  
SCK  
SS  
CR  
SPIE SPE SPR2 MSTR CPOL CPHA SPR1 SPR0  
MASTER  
CONTROL  
SERIAL  
CLOCK  
GENERATOR  
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SERIAL PERIPHERAL INTERFACE (Cont’d)  
11.3.4 Functional Description  
Transmit sequence  
Figure 36 shows the serial peripheral interface  
(SPI) block diagram.  
The transmit sequence begins when a byte is writ-  
ten the DR register.  
This interface contains three dedicated registers:  
– A Control Register (CR)  
The data byte is parallel loaded into the 8-bit shift  
register (from the internal bus) during a write cycle  
and then shifted out serially to the MOSI pin most  
significant bit first.  
– A Status Register (SR)  
– A Data Register (DR)  
When data transfer is complete:  
– The SPIF bit is set by hardware  
Refer to the CR, SR and DR registers in Section  
11.3.7 for the bit definitions.  
– An interrupt is generated if the SPIE bit is set  
and the I bit in the CCR register is cleared.  
11.3.4.1 Master Configuration  
In a master configuration, the serial clock is gener-  
ated on the SCK pin.  
During the last clock cycle the SPIF bit is set, a  
copy of the data byte received in the shift register  
is moved to a buffer. When the DR register is read,  
the SPI peripheral returns this buffered value.  
Procedure  
– Select the SPR0 and SPR1 bits to define the  
serial clock baud rate (see CR register).  
Clearing the SPIF bit is performed by the following  
software sequence:  
– Select the CPOL and CPHA bits to define one  
of the four relationships between the data  
transfer and the serial clock (see Figure 39).  
1. An access to the SR register while the SPIF bit  
is set  
2. A read to the DR register.  
– The SS pin must be connected to a high level  
signal during the complete byte transmit se-  
quence.  
Note: While the SPIF bit is set, all writes to the DR  
register are inhibited until the SR register is read.  
– The MSTR and SPE bits must be set (they re-  
main set only if the SS pin is connected to a  
high level signal).  
In this configuration the MOSI pin is a data output  
and to the MISO pin is a data input.  
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ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
SERIAL PERIPHERAL INTERFACE (Cont’d)  
11.3.4.2 Slave Configuration  
When data transfer is complete:  
– The SPIF bit is set by hardware  
In slave configuration, the serial clock is received  
on the SCK pin from the master device.  
– An interrupt is generated if SPIE bit is set and  
I bit in CCR register is cleared.  
The value of the SPR0 & SPR1 bits is not used for  
the data transfer.  
During the last clock cycle the SPIF bit is set, a  
copy of the data byte received in the shift register  
is moved to a buffer. When the DR register is read,  
the SPI peripheral returns this buffered value.  
Procedure  
– For correct data transfer, the slave device  
must be in the same timing mode as the mas-  
ter device (CPOL and CPHA bits). See Figure  
39.  
Clearing the SPIF bit is performed by the following  
software sequence:  
– The SS pin must be connected to a low level  
signal during the complete byte transmit se-  
quence.  
1. An access to the SR register while the SPIF bit  
is set.  
2. A read to the DR register.  
– Clear the MSTR bit and set the SPE bit to as-  
sign the pins to alternate function.  
Notes: While the SPIF bit is set, all writes to the  
DR register are inhibited until the SR register is  
read.  
In this configuration the MOSI pin is a data input  
and the MISO pin is a data output.  
The SPIF bit can be cleared during a second  
transmission; however, it must be cleared before  
the second SPIF bit in order to prevent an overrun  
condition (see Section 11.3.4.6).  
Transmit Sequence  
The data byte is parallel loaded into the 8-bit shift  
register (from the internal bus) during a write cycle  
and then shifted out serially to the MISO pin most  
significant bit first.  
Depending on the CPHA bit, the SS pin has to be  
set to write to the DR register between each data  
byte transfer to avoid a write collision (see Section  
11.3.4.4).  
The transmit sequence begins when the slave de-  
vice receives the clock signal and the most signifi-  
cant bit of the data on its MOSI pin.  
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SERIAL PERIPHERAL INTERFACE (Cont’d)  
11.3.4.3 Data Transfer Format  
CPHA bit is set  
During an SPI transfer, data is simultaneously  
transmitted (shifted out serially) and received  
(shifted in serially). The serial clock is used to syn-  
chronize the data transfer during a sequence of  
eight clock pulses.  
The second edge on the SCK pin (falling edge if  
the CPOL bit is reset, rising edge if the CPOL bit is  
set) is the MSBit capture strobe. Data is latched on  
the occurrence of the second clock transition.  
No write collision should occur even if the SS pin  
stays low during a transfer of several bytes (see  
Figure 38).  
The SS pin allows individual selection of a slave  
device; the other slave devices that are not select-  
ed do not interfere with the SPI transfer.  
CPHA bit is reset  
Clock Phase and Clock Polarity  
The first edge on the SCK pin (falling edge if CPOL  
bit is set, rising edge if CPOL bit is reset) is the  
MSBit capture strobe. Data is latched on the oc-  
currence of the first clock transition.  
Four possible timing relationships may be chosen  
by software, using the CPOL and CPHA bits.  
The CPOL (clock polarity) bit controls the steady  
state value of the clock when no data is being  
transferred. This bit affects both master and slave  
modes.  
The SS pin must be toggled high and low between  
each byte transmitted (see Figure 38).  
To protect the transmission from a write collision a  
low value on the SS pin of a slave device freezes  
the data in its DR register and does not allow it to  
be altered. Therefore the SS pin must be high to  
write a new data byte in the DR without producing  
a write collision.  
The combination between the CPOL and CPHA  
(clock phase) bits selects the data capture clock  
edge.  
Figure 39, shows an SPI transfer with the four  
combinations of the CPHA and CPOL bits. The di-  
agram may be interpreted as a master or slave  
timing diagram where the SCK pin, the MISO pin,  
the MOSI pin are directly connected between the  
master and the slave device.  
The SS pin is the slave device select input and can  
be driven by the master device.  
The master device applies data to its MOSI pin-  
clock edge before the capture clock edge.  
Figure 38. CPHA / SS Timing Diagram  
Byte 3  
Byte 2  
MOSI/MISO  
Master SS  
Byte 1  
Slave SS  
(CPHA=0)  
Slave SS  
(CPHA=1)  
VR02131A  
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SERIAL PERIPHERAL INTERFACE (Cont’d)  
Figure 39. Data Clock Timing Diagram  
CPHA =1  
SCLK (with  
CPOL = 1)  
SCLK (with  
CPOL = 0)  
Bit 4  
Bit 4  
Bit3  
Bit 2  
Bit 2  
Bit 1  
Bit 1  
LSBit  
LSBit  
MSBit  
MSBit  
Bit 6  
Bit 6  
Bit 5  
Bit 5  
MISO  
(from master)  
Bit3  
MOSI  
(from slave)  
SS  
(to slave)  
CAPTURE STROBE  
CPHA =0  
CPOL = 1  
CPOL = 0  
Bit 4  
Bit 4  
Bit3  
Bit 2  
Bit 2  
Bit 1  
Bit 1  
LSBit  
LSBit  
MSBit  
Bit 6  
Bit 6  
Bit 5  
Bit 5  
MISO  
(from master)  
MSBit  
Bit3  
MOSI  
(from slave)  
SS  
(to slave)  
CAPTURE STROBE  
Note: This figure should not be used as a replacement for parametric information.  
Refer to the Electrical Characteristics chapter.  
VR02131B  
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ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
SERIAL PERIPHERAL INTERFACE (Cont’d)  
11.3.4.4 Write Collision Error  
When the CPHA bit is reset:  
A write collision occurs when the software tries to  
write to the DR register while a data transfer is tak-  
ing place with an external device. When this hap-  
pens, the transfer continues uninterrupted; and  
the software write will be unsuccessful.  
Data is latched on the occurrence of the first clock  
transition. The slave device does not have any  
way of knowing when that transition will occur;  
therefore, the slave device collision occurs when  
software attempts to write the DR register after its  
SS pin has been pulled low.  
Write collisions can occur both in master and slave  
mode.  
For this reason, the SS pin must be high, between  
each data byte transfer, to allow the CPU to write  
in the DR register without generating a write colli-  
sion.  
Note: A “read collision” will never occur since the  
received data byte is placed in a buffer in which  
access is always synchronous with the MCU oper-  
ation.  
In Master mode  
In Slave mode  
Collision in the master device is defined as a write  
of the DR register while the internal serial clock  
(SCK) is in the process of transfer.  
When the CPHA bit is set:  
The slave device will receive a clock (SCK) edge  
prior to the latch of the first data transfer. This first  
clock edge will freeze the data in the slave device  
DR register and output the MSBit on to the exter-  
nal MISO pin of the slave device.  
The SS pin signal must be always high on the  
master device.  
WCOL bit  
The WCOL bit in the SR register is set if a write  
collision occurs.  
The SS pin low state enables the slave device but  
the output of the MSBit onto the MISO pin does  
not take place until the first data transfer clock  
edge.  
No SPI interrupt is generated when the WCOL bit  
is set (the WCOL bit is a status flag only).  
Clearing the WCOL bit is done through a software  
sequence (see Figure 40).  
Figure 40. Clearing the WCOL bit (Write Collision Flag) Software Sequence  
Clearing sequence after SPIF = 1 (end of a data byte transfer)  
Read SR  
Read SR  
1st Step  
2nd Step  
OR  
THEN  
THEN  
SPIF =0  
WCOL=0  
SPIF =0  
WCOL=0 if no transfer has started  
WCOL=1 if a transfer has started  
before the 2nd step  
Read DR  
Write DR  
Clearing sequence before SPIF = 1 (during a data byte transfer)  
Read SR  
1st Step  
THEN  
Note: Writing to the DR register  
2nd Step  
Read DR  
instead of reading in it does not  
reset the WCOL bit.  
WCOL=0  
66/135  
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
SERIAL PERIPHERAL INTERFACE (Cont’d)  
11.3.4.5 Master Mode Fault  
may be restored to their original state during or af-  
ter this clearing sequence.  
Master mode fault occurs when the master device  
has its SS pin pulled low, then the MODF bit is set.  
Hardware does not allow the user to set the SPE  
and MSTR bits while the MODF bit is set except in  
the MODF bit clearing sequence.  
Master mode fault affects the SPI peripheral in the  
following ways:  
In a slave device the MODF bit cannot be set, but  
in a multi master configuration the device can be in  
slave mode with this MODF bit set.  
– The MODF bit is set and an SPI interrupt is  
generated if the SPIE bit is set.  
– The SPE bit is reset. This blocks all output  
from the device and disables the SPI periph-  
eral.  
The MODF bit indicates that there might have  
been a multimaster conflict for system control and  
allows a proper exit from system operation to a re-  
set or default system state using an interrupt rou-  
tine.  
– The MSTR bit is reset, thus forcing the device  
into slave mode.  
Clearing the MODF bit is done through a software  
sequence:  
11.3.4.6 Overrun Condition  
An overrun condition occurs when the master de-  
vice has sent several data bytes and the slave de-  
vice has not cleared the SPIF bit issuing from the  
previous data byte transmitted.  
1. A read or write access to the SR register while  
the MODF bit is set.  
2. A write to the CR register.  
In this case, the receiver buffer contains the byte  
sent after the SPIF bit was last cleared. A read to  
the DR register returns this byte. All other bytes  
are lost.  
Notes: To avoid any multiple slave conflicts in the  
case of a system comprising several MCUs, the  
SS pin must be pulled high during the clearing se-  
quence of the MODF bit. The SPE and MSTR bits  
This condition is not detected by the SPI peripher-  
al.  
67/135  
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
SERIAL PERIPHERAL INTERFACE (Cont’d)  
11.3.4.7 Single Master and Multimaster Configurations  
There are two types of SPI systems:  
– Single Master System  
– Multimaster System  
For more security, the slave device may respond  
to the master with the received data byte. Then the  
master will receive the previous byte back from the  
slave device if all MISO and MOSI pins are con-  
nected and the slave has not written its DR regis-  
ter.  
Single Master System  
A typical single master system may be configured,  
using an MCU as the master and four MCUs as  
slaves (see Figure 41).  
Other transmission security methods can use  
ports for handshake lines or data bytes with com-  
mand fields.  
The master device selects the individual slave de-  
vices by using four pins of a parallel port to control  
the four SS pins of the slave devices.  
Multimaster System  
A multimaster system may also be configured by  
the user. Transfer of master control could be im-  
plemented using a handshake method through the  
I/O ports or by an exchange of code messages  
through the serial peripheral interface system.  
The SS pins are pulled high during reset since the  
master device ports will be forced to be inputs at  
that time, thus disabling the slave devices.  
Note: To prevent a bus conflict on the MISO line  
the master allows only one active slave device  
during a transmission.  
The multi-master system is principally handled by  
the MSTR bit in the CR register and the MODF bit  
in the SR register.  
Figure 41. Single Master Configuration  
SS  
SS  
SS  
SS  
SCK  
SCK  
Slave  
SCK  
Slave  
SCK  
Slave  
Slave  
MCU  
MCU  
MCU  
MCU  
MOSI MISO  
MOSI MISO  
MOSI MISO  
MOSI MISO  
MOSI MISO  
SCK  
Master  
MCU  
5V  
SS  
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SERIAL PERIPHERAL INTERFACE (Cont’d)  
11.3.5 Low Power Modes  
Mode  
Description  
No effect on SPI.  
WAIT  
SPI interrupt events cause the device to exit from WAIT mode.  
SPI registers are frozen.  
HALT  
In HALT mode, the SPI is inactive. SPI operation resumes when the MCU is woken up by an interrupt with  
“exit from HALT mode” capability.  
11.3.6 Interrupts  
Enable  
Control from  
Bit  
Exit  
Exit  
from  
Halt  
No  
No  
Event  
Flag  
Interrupt Event  
Wait  
Yes  
Yes  
SPI End of Transfer Event  
Master Mode Fault Event  
SPIF  
SPIE  
MODF  
Note: The SPI interrupt events are connected to  
the same interrupt vector (see Interrupts chapter).  
They generate an interrupt if the corresponding  
Enable Control Bit is set and the interrupt mask in  
the CC register is reset (RIM instruction).  
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SERIAL PERIPHERAL INTERFACE (Cont’d)  
11.3.7 Register Description  
CONTROL REGISTER (CR)  
Read/Write  
Bit 3 = CPOL Clock polarity.  
This bit is set and cleared by software. This bit de-  
termines the steady state of the serial Clock. The  
CPOL bit affects both the master and slave  
modes.  
Reset Value: 0000xxxx (0xh)  
7
0
SPIE SPE SPR2 MSTR CPOL CPHA SPR1 SPR0  
0: The steady state is a low value at the SCK pin.  
1: The steady state is a high value at the SCK pin.  
Bit 7 = SPIE Serial peripheral interrupt enable.  
This bit is set and cleared by software.  
0: Interrupt is inhibited  
1: An SPI interrupt is generated whenever SPIF=1  
or MODF=1 in the SR register  
Bit 2 = CPHA Clock phase.  
This bit is set and cleared by software.  
0: The first clock transition is the first data capture  
edge.  
1: The second clock transition is the first capture  
edge.  
Bit 6 = SPE Serial peripheral output enable.  
This bit is set and cleared by software. It is also  
cleared by hardware when, in master mode, SS=0  
(see Section 11.3.4.5 "Master Mode Fault" on  
page 67).  
Bit 1:0 = SPR[1:0] Serial peripheral rate.  
These bits are set and cleared by software.Used  
with the SPR2 bit, they select one of six baud rates  
to be used as the serial clock when the device is a  
master.  
0: I/O port connected to pins  
1: SPI alternate functions connected to pins  
The SPE bit is cleared by reset, so the SPI periph-  
eral is not initially connected to the external pins.  
These 2 bits have no effect in slave mode.  
Table 15. Serial Peripheral Baud Rate  
Bit 5 = SPR2 Divider Enable.  
Serial Clock  
SPR2 SPR1 SPR0  
this bit is set and cleared by software and it is  
cleared by reset. It is used with the SPR[1:0] bits to  
set the baud rate. Refer to Table 15.  
0: Divider by 2 enabled  
f
f
/4  
/8  
1
0
0
1
0
0
0
0
0
1
1
1
0
0
1
0
0
1
CPU  
CPU  
f
f
f
/16  
/32  
/64  
CPU  
CPU  
CPU  
1: Divider by 2 disabled  
f
/128  
CPU  
Bit 4 = MSTR Master.  
This bit is set and cleared by software. It is also  
cleared by hardware when, in master mode, SS=0  
(see Section 11.3.4.5 "Master Mode Fault" on  
page 67).  
0: Slave mode is selected  
1: Master mode is selected, the function of the  
SCK pin changes from an input to an output and  
the functions of the MISO and MOSI pins are re-  
versed.  
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SERIAL PERIPHERAL INTERFACE (Cont’d)  
STATUS REGISTER (SR)  
Read Only  
DATA I/O REGISTER (DR)  
Read/Write  
Reset Value: 0000 0000 (00h)  
Reset Value: Undefined  
7
0
-
7
0
SPIF WCOL  
-
MODF  
-
-
-
D7  
D6  
D5  
D4  
D3  
D2  
D1  
D0  
Bit 7 = SPIF Serial Peripheral data transfer flag.  
This bit is set by hardware when a transfer has  
been completed. An interrupt is generated if  
SPIE=1 in the CR register. It is cleared by a soft-  
ware sequence (an access to the SR register fol-  
lowed by a read or write to the DR register).  
0: Data transfer is in progress or has been ap-  
proved by a clearing sequence.  
The DR register is used to transmit and receive  
data on the serial bus. In the master device only a  
write to this register will initiate transmission/re-  
ception of another byte.  
Notes: During the last clock cycle the SPIF bit is  
set, a copy of the received data byte in the shift  
register is moved to a buffer. When the user reads  
the serial peripheral data I/O register, the buffer is  
actually being read.  
1: Data transfer between the device and an exter-  
nal device has been completed.  
Warning:  
Note: While the SPIF bit is set, all writes to the DR  
register are inhibited.  
A write to the DR register places data directly into  
the shift register for transmission.  
A read to the DR register returns the value located  
in the buffer and not the contents of the shift regis-  
ter (See Figure 37).  
Bit 6 = WCOL Write Collision status.  
This bit is set by hardware when a write to the DR  
register is done during a transmit sequence. It is  
cleared by a software sequence (see Figure 40).  
0: No write collision occurred  
1: A write collision has been detected  
Bit 5 = Unused.  
Bit 4 = MODF Mode Fault flag.  
This bit is set by hardware when the SS pin is  
pulled low in master mode (see Section 11.3.4.5  
"Master Mode Fault" on page 67). An SPI interrupt  
can be generated if SPIE=1 in the CR register.  
This bit is cleared by a software sequence (An ac-  
cess to the SR register while MODF=1 followed by  
a write to the CR register).  
0: No master mode fault detected  
1: A fault in master mode has been detected  
Bits 3:0 = Unused.  
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SERIAL PERIPHERAL INTERFACE (Cont’d)  
Table 16. SPI Register Map and Reset Values  
Address  
(Hex.)  
Register  
Label  
7
6
5
4
3
2
1
0
SPIDR  
Reset Value  
MSB  
x
LSB  
x
0021h  
0022h  
0023h  
x
x
x
x
x
x
SPICR  
Reset Value  
SPIE  
0
SPE  
0
SPR2  
0
MSTR  
0
CPOL  
x
CPHA  
x
SPR1  
x
SPR0  
x
SPISR  
Reset Value  
SPIF  
0
WCOL  
0
MODF  
0
0
0
0
0
0
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2
11.4 I C BUS INTERFACE (I2C)  
11.4.1 Introduction  
handshake. The interrupts are enabled or disabled  
2
2
by software. The interface is connected to the I C  
The I C Bus Interface serves as an interface be-  
2
bus by a data pin (SDAI) and by a clock pin (SCLI).  
tween the microcontroller and the serial I C bus. It  
2
It can be connected both with a standard I C bus  
provides both multimaster and slave functions,  
2
2
and a Fast I C bus. This selection is made by soft-  
and controls all I C bus-specific sequencing, pro-  
2
ware.  
tocol, arbitration and timing. It supports fast I C  
mode (400 kHz).  
Mode Selection  
11.4.2 Main Features  
Parallel-bus/I C protocol converter  
The interface can operate in the four following  
modes:  
2
– Slave transmitter/receiver  
Multi-master capability  
– Master transmitter/receiver  
By default, it operates in slave mode.  
7-bit/10-bit Addressing  
Transmitter/Receiver flag  
End-of-byte transmission flag  
Transfer problem detection  
The interface automatically switches from slave to  
master after it generates a START condition and  
from master to slave in case of arbitration loss or a  
STOP generation, allowing then Multi-Master ca-  
pability.  
2
I C Master Features  
Clock generation  
2
I C bus busy flag  
Communication Flow  
Arbitration Lost Flag  
In Master mode, it initiates a data transfer and  
generates the clock signal. A serial data transfer  
always begins with a start condition and ends with  
a stop condition. Both start and stop conditions are  
generated in master mode by software.  
End of byte transmission flag  
Transmitter/Receiver Flag  
Start bit detection flag  
Start and Stop generation  
In Slave mode, the interface is capable of recog-  
nising its own address (7 or 10-bit), and the Gen-  
eral Call address. The General Call address de-  
tection may be enabled or disabled by software.  
2
I C Slave Features  
Stop bit detection  
2
I C bus busy flag  
Data and addresses are transferred as 8-bit bytes,  
MSB first. The first byte(s) following the start con-  
dition contain the address (one in 7-bit mode, two  
in 10-bit mode). The address is always transmitted  
in Master mode.  
Detection of misplaced start or stop condition  
Programmable I C Address detection  
Transfer problem detection  
End-of-byte transmission flag  
Transmitter/Receiver flag  
11.4.3 General Description  
2
A 9th clock pulse follows the 8 clock cycles of a  
byte transfer, during which the receiver must send  
an acknowledge bit to the transmitter. Refer to Fig-  
ure 42.  
In addition to receiving and transmitting data, this  
interface converts it from serial to parallel format  
and vice versa, using either an interrupt or polled  
2
Figure 42. I C BUS Protocol  
SDA  
MSB  
ACK  
SCL  
1
2
8
9
START  
STOP  
CONDITION  
CONDITION  
VR02119B  
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2
I C BUS INTERFACE (Cont’d)  
Acknowledge may be enabled and disabled by  
software.  
The SCL frequency (f  
) is controlled by a pro-  
SCL  
grammable clock divider which depends on the  
2
2
I C bus mode.  
The I C interface address and/or general call ad-  
2
dress can be selected by software.  
When the I C cell is enabled, the SDA and SCL  
2
ports must be configured as floating inputs. In this  
case, the value of the external pull-up resistor  
used depends on the application.  
The speed of the I C interface may be selected  
2
between Standard (up to 100 kHz) and Fast I C  
(up to 400 kHz).  
2
When the I C cell is disabled, the SDA and SCL  
SDA/SCL Line Control  
ports revert to being standard I/O port pins.  
Transmitter mode: the interface holds the clock  
line low before transmission to wait for the micro-  
controller to write the byte in the Data Register.  
Receiver mode: the interface holds the clock line  
low after reception to wait for the microcontroller to  
read the byte in the Data Register.  
2
Figure 43. I C Interface Block Diagram  
DATA REGISTER (DR)  
DATA CONTROL  
SDA or SDAI  
DATA SHIFT REGISTER  
COMPARATOR  
OWN ADDRESS REGISTER 1 (OAR1)  
OWN ADDRESS REGISTER 2 (OAR2)  
CLOCK CONTROL  
SCL or SCLI  
CLOCK CONTROL REGISTER (CCR)  
CONTROL REGISTER (CR)  
STATUS REGISTER 1 (SR1)  
STATUS REGISTER 2 (SR2)  
CONTROL LOGIC  
INTERRUPT  
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2
I C BUS INTERFACE (Cont’d)  
11.4.4 Functional Description  
Then the interface waits for a read of the SR1 reg-  
ister followed by a read of the DR register, holding  
the SCL line low (see Figure 44 Transfer se-  
quencing EV2).  
Refer to the CR, SR1 and SR2 registers in Section  
11.4.7. for the bit definitions.  
2
By default the I C interface operates in Slave  
Slave Transmitter  
mode (M/SL bit is cleared) except when it initiates  
a transmit or receive sequence.  
Following the address reception and after SR1  
register has been read, the slave sends bytes from  
the DR register to the SDA line via the internal shift  
register.  
First the interface frequency must be configured  
using the FRi bits in the OAR2 register.  
11.4.4.1 Slave Mode  
The slave waits for a read of the SR1 register fol-  
lowed by a write in the DR register, holding the  
SCL line low (see Figure 44 Transfer sequencing  
EV3).  
As soon as a start condition is detected, the  
address is received from the SDA line and sent to  
the shift register; then it is compared with the  
address of the interface or the General Call  
address (if selected by software).  
When the acknowledge pulse is received:  
– The EVF and BTF bits are set by hardware with  
an interrupt if the ITE bit is set.  
Note: In 10-bit addressing mode, the comparison  
includes the header sequence (11110xx0) and the  
two most significant bits of the address.  
Closing slave communication  
Header matched (10-bit mode only): the interface  
generates an acknowledge pulse if the ACK bit is  
set.  
After the last data byte is transferred a Stop Con-  
dition is generated by the master. The interface  
detects this condition and sets:  
Address not matched: the interface ignores it  
and waits for another Start condition.  
– EVF and STOPF bits with an interrupt if the ITE  
bit is set.  
Address matched: the interface generates in se-  
quence:  
Then the interface waits for a read of the SR2 reg-  
ister (see Figure 44 Transfer sequencing EV4).  
– Acknowledge pulse if the ACK bit is set.  
Error Cases  
– EVF and ADSL bits are set with an interrupt if the  
ITE bit is set.  
BERR: Detection of a Stop or a Start condition  
during a byte transfer. In this case, the EVF and  
the BERR bits are set with an interrupt if the ITE  
bit is set.  
If it is a Stop then the interface discards the data,  
released the lines and waits for another Start  
condition.  
Then the interface waits for a read of the SR1 reg-  
ister, holding the SCL line low (see Figure 44  
Transfer sequencing EV1).  
Next, in 7-bit mode read the DR register to deter-  
mine from the least significant bit (Data Direction  
Bit) if the slave must enter Receiver or Transmitter  
mode.  
If it is a Start then the interface discards the data  
and waits for the next slave address on the bus.  
AF: Detection of a non-acknowledge bit. In this  
case, the EVF and AF bits are set with an inter-  
rupt if the ITE bit is set.  
In 10-bit mode, after receiving the address se-  
quence the slave is always in receive mode. It will  
enter transmit mode on receiving a repeated Start  
condition followed by the header sequence with  
matching address bits and the least significant bit  
set (11110xx1).  
The AF bit is cleared by reading the I2CSR2 reg-  
ister. However, if read before the completion of  
the transmission, the AF flag will be set again,  
thus possibly generating a new interrupt. Soft-  
ware must ensure either that the SCL line is back  
at 0 before reading the SR2 register, or be able  
to correctly handle a second interrupt during the  
9th pulse of a transmitted byte.  
Slave Receiver  
Following the address reception and after SR1  
register has been read, the slave receives bytes  
from the SDA line into the DR register via the inter-  
nal shift register. After each byte the interface gen-  
erates in sequence:  
Note: In both cases, SCL line is not held low; how-  
ever, the SDA line can remain low if the last bits  
transmitted are all 0. It is then necessary to re-  
lease both lines by software. The SCL line is not  
held low while AF = 1 but by other flags (SB or  
BTF) that are set at the same time.  
– Acknowledge pulse if the ACK bit is set  
– EVF and BTF bits are set with an interrupt if the  
ITE bit is set.  
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2
I C BUS INTERFACE (Cont’d)  
How to release the SDA / SCL lines  
Then the second address byte is sent by the inter-  
face.  
Set and subsequently clear the STOP bit while  
BTF is set. The SDA/SCL lines are released after  
the transfer of the current byte.  
After completion of this transfer (and acknowledge  
from the slave if the ACK bit is set):  
SMBus Compatibility  
– The EVF bit is set by hardware with interrupt  
generation if the ITE bit is set.  
2
ST7 I C is compatible with SMBus V1.1 protocol. It  
supports all SMBus addressing modes, SMBus  
bus protocols and CRC-8 packet error checking.  
Refer to AN1713: SMBus Slave Driver For ST7  
Then the master waits for a read of the SR1 regis-  
ter followed by a write in the CR register (for exam-  
ple set PE bit), holding the SCL line low (see Fig-  
ure 44 Transfer sequencing EV6).  
2
I C Peripheral.  
11.4.4.2 Master Mode  
Next the master must enter Receiver or Transmit-  
ter mode.  
To switch from default Slave mode to Master  
mode a Start condition generation is needed.  
Note: In 10-bit addressing mode, to switch the  
master to Receiver mode, software must generate  
a repeated Start condition and resend the header  
sequence with the least significant bit set  
(11110xx1).  
Start condition  
Setting the START bit while the BUSY bit is  
cleared causes the interface to switch to Master  
mode (M/SL bit set) and generates a Start condi-  
tion.  
Master Receiver  
Following the address transmission and after SR1  
and CR registers have been accessed, the master  
receives bytes from the SDA line into the DR reg-  
ister via the internal shift register. After each byte  
the interface generates in sequence:  
Once the Start condition is sent:  
– The EVF and SB bits are set by hardware with  
an interrupt if the ITE bit is set.  
Then the master waits for a read of the SR1 regis-  
ter followed by a write in the DR register with the  
Slave address, holding the SCL line low (see  
Figure 44 Transfer sequencing EV5).  
– Acknowledge pulse if the ACK bit is set  
– EVF and BTF bits are set by hardware with an in-  
terrupt if the ITE bit is set.  
Slave address transmission  
Then the interface waits for a read of the SR1 reg-  
ister followed by a read of the DR register, holding  
the SCL line low (see Figure 44 Transfer se-  
quencing EV7).  
Then the slave address is sent to the SDA line via  
the internal shift register.  
In 7-bit addressing mode, one address byte is  
sent.  
To close the communication: before reading the  
last byte from the DR register, set the STOP bit to  
generate the Stop condition. The interface goes  
automatically back to slave mode (M/SL bit  
cleared).  
In 10-bit addressing mode, sending the first byte  
including the header sequence causes the follow-  
ing event:  
– The EVF bit is set by hardware with interrupt  
generation if the ITE bit is set.  
Then the master waits for a read of the SR1 regis-  
ter followed by a write in the DR register, holding  
the SCL line low (see Figure 44 Transfer se-  
quencing EV9).  
Note: In order to generate the non-acknowledge  
pulse after the last received data byte, the ACK bit  
must be cleared just before reading the second  
last data byte.  
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2
I C BUS INTERFACE (Cont’d)  
Master Transmitter  
sion.  
Multimaster Mode  
Following the address transmission and after SR1  
register has been read, the master sends bytes  
from the DR register to the SDA line via the inter-  
nal shift register.  
Normally the BERR bit would be set whenever  
unauthorized transmission takes place while  
transfer is already in progress. However, an is-  
sue will arise if an external master generates an  
2
The master waits for a read of the SR1 register fol-  
lowed by a write in the DR register, holding the  
SCL line low (see Figure 44 Transfer sequencing  
EV8).  
unauthorized Start or Stop while the I C master  
is on the first pulse of a 9-bit transaction. It is pos-  
sible to work around this by polling the BUSY bit  
2
during I C master mode transmission. The reset-  
ting of the BUSY bit can then be handled in a  
similar manner as the BERR flag being set.  
When the acknowledge bit is received, the  
interface sets:  
AF: Detection of a non-acknowledge bit. In this  
case, the EVF and AF bits are set by hardware  
with an interrupt if the ITE bit is set. To resume,  
set the Start or Stop bit.  
The AF bit is cleared by reading the I2CSR2 reg-  
ister. However, if read before the completion of  
the transmission, the AF flag will be set again,  
thus possibly generating a new interrupt. Soft-  
ware must ensure either that the SCL line is back  
at 0 before reading the SR2 register, or be able  
to correctly handle a second interrupt during the  
9th pulse of a transmitted byte.  
– EVF and BTF bits with an interrupt if the ITE bit  
is set.  
To close the communication: after writing the last  
byte to the DR register, set the STOP bit to gener-  
ate the Stop condition. The interface goes auto-  
matically back to slave mode (M/SL bit cleared).  
Error Cases  
BERR: Detection of a Stop or a Start condition  
during a byte transfer. In this case, the EVF and  
BERR bits are set by hardware with an interrupt  
if ITE is set.  
Note that BERR will not be set if an error is de-  
tected during the first pulse of each 9-bit transac-  
tion:  
ARLO: Detection of an arbitration lost condition.  
In this case the ARLO bit is set by hardware (with  
an interrupt if the ITE bit is set and the interface  
goes automatically back to slave mode (the M/SL  
bit is cleared).  
Single Master Mode  
If a Start or Stop is issued during the first pulse of  
a 9-bit transaction, the BERR flag will not be set  
and transfer will continue however the BUSY flag  
will be reset. To work around this, slave devices  
should issue a NACK when they receive a mis-  
placed Start or Stop. The reception of a NACK or  
BUSY by the master in the middle of communica-  
tion gives the possibility to reinitiate transmis-  
Note: In all these cases, the SCL line is not held  
low; however, the SDA line can remain low if the  
last bits transmitted are all 0. It is then necessary  
to release both lines by software. The SCL line is  
not held low while AF = 1 but by other flags (SB or  
BTF) that are set at the same time.  
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2
I C BUS INTERFACE (Cont’d)  
Figure 44. Transfer Sequencing  
7-bit Slave receiver:  
S
Address  
A
Data1  
A
Data1  
Data1  
Data2  
EV3  
A
Data2  
Data2  
DataN  
A
P
.....  
EV1  
EV2  
A
EV2  
A
EV2  
NA  
EV4  
7-bit Slave transmitter:  
S
Address  
A
DataN  
P
.....  
.....  
EV1 EV3  
EV3  
EV3-1  
EV4  
7-bit Master receiver:  
S
Address  
A
A
A
DataN NA  
P
EV5  
EV6  
EV7  
A
EV7  
A
EV7  
A
7-bit Master transmitter:  
S
Address  
A
Data1  
Data2  
DataN  
P
.....  
EV5  
EV6 EV8  
EV8  
EV8  
EV8  
10-bit Slave receiver:  
S
Header  
A
Address  
A
Data1  
A
DataN  
A
P
.....  
EV1  
EV2  
EV2  
EV4  
10-bit Slave transmitter:  
S
Header  
A
Data1  
A
A
DataN  
....  
.
A
P
r
EV1 EV3  
EV6 EV8  
EV3  
EV3-1  
EV4  
10-bit Master transmitter  
S
Header  
A
Address  
A
Data1  
DataN  
A
P
.....  
EV5  
EV9  
EV8  
A
EV8  
A
10-bit Master receiver:  
S
Header  
A
Data1  
DataN  
P
r
.....  
EV5  
EV6  
EV7  
EV7  
Legend: S=Start, S = Repeated Start, P=Stop, A=Acknowledge, NA=Non-acknowledge,  
r
EVx=Event (with interrupt if ITE=1)  
EV1: EVF=1, ADSL=1, cleared by reading SR1 register.  
EV2: EVF=1, BTF=1, cleared by reading SR1 register followed by reading DR register.  
EV3: EVF=1, BTF=1, cleared by reading SR1 register followed by writing DR register.  
EV3-1: EVF=1, AF=1, BTF=1; AF is cleared by reading SR1 register. BTF is cleared by releasing the  
lines (STOP=1, STOP=0) or by writing DR register (DR=FFh). Note: If lines are released by  
STOP=1, STOP=0, the subsequent EV4 is not seen.  
EV4: EVF=1, STOPF=1, cleared by reading SR2 register.  
EV5: EVF=1, SB=1, cleared by reading SR1 register followed by writing DR register.  
EV6: EVF=1, cleared by reading SR1 register followed by writing CR register (for example PE=1).  
EV7: EVF=1, BTF=1, cleared by reading SR1 register followed by reading DR register.  
EV8: EVF=1, BTF=1, cleared by reading SR1 register followed by writing DR register.  
EV9: EVF=1, ADD10=1, cleared by reading SR1 register followed by writing DR register.  
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2
I C BUS INTERFACE (Cont’d)  
11.4.5 Low Power Modes  
Mode  
Description  
2
No effect on I C interface.  
WAIT  
2
I C interrupts cause the device to exit from WAIT mode.  
2
I C registers are frozen.  
2
2
HALT  
In HALT mode, the I C interface is inactive and does not acknowledge data on the bus. The I C interface  
resumes operation when the MCU is woken up by an interrupt with “exit from HALT mode” capability.  
11.4.6 Interrupts  
Figure 45. Event Flags and Interrupt Generation  
ADD10  
ITE  
BTF  
ADSL  
SB  
INTERRUPT  
EVF  
AF  
STOPF  
ARLO  
BERR  
*
* EVF can also be set by EV6 or an error from the SR2 register.  
Enable  
Control from  
Bit  
Exit  
Exit  
from  
Halt  
Event  
Flag  
Interrupt Event  
Wait  
Yes  
Yes  
Yes  
Yes  
Yes  
Yes  
Yes  
Yes  
10-bit Address Sent Event (Master mode)  
End of Byte Transfer Event  
ADD10  
BTF  
No  
No  
No  
No  
No  
No  
No  
No  
Address Matched Event (Slave mode)  
Start Bit Generation Event (Master mode)  
Acknowledge Failure Event  
ADSL  
SB  
ITE  
AF  
Stop Detection Event (Slave mode)  
Arbitration Lost Event (Multimaster configuration)  
Bus Error Event  
STOPF  
ARLO  
BERR  
2
Note: The I C interrupt events are connected to  
the same interrupt vector (see Interrupts chapter).  
They generate an interrupt if the corresponding  
Enable Control Bit is set and the I-bit in the CC reg-  
ister is reset (RIM instruction).  
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2
I C BUS INTERFACE (Cont’d)  
11.4.7 Register Description  
– In slave mode:  
2
0: No start generation  
I C CONTROL REGISTER (CR)  
1: Start generation when the bus is free  
Read / Write  
Reset Value: 0000 0000 (00h)  
Bit 2 = ACK Acknowledge enable.  
This bit is set and cleared by software. It is also  
cleared by hardware when the interface is disa-  
bled (PE=0).  
7
0
0
0
PE ENGC START ACK STOP ITE  
0: No acknowledge returned  
1: Acknowledge returned after an address byte or  
a data byte is received  
Bit 7:6 = Reserved. Forced to 0 by hardware.  
Bit 1 = STOP Generation of a Stop condition.  
This bit is set and cleared by software. It is also  
cleared by hardware in master mode.  
Note: This bit is not cleared when the interface is  
disabled (PE=0).  
Bit 5 = PE Peripheral enable.  
This bit is set and cleared by software.  
0: Peripheral disabled  
1: Master/Slave capability  
Notes:  
– In master mode:  
0: No stop generation  
1: Stop generation after the current byte transfer  
or after the current Start condition is sent. The  
STOP bit is cleared by hardware when the Stop  
condition is sent.  
– When PE=0, all the bits of the CR register and  
the SR register except the Stop bit are reset. All  
outputs are released while PE=0  
– When PE=1, the corresponding I/O pins are se-  
lected by hardware as alternate functions.  
2
– To enable the I C interface, write the CR register  
TWICE with PE=1 as the first write only activates  
– In slave mode:  
0: No stop generation  
the interface (only PE is set).  
1: Release the SCL and SDA lines after the cur-  
rent byte transfer (BTF=1). In this mode the  
STOP bit has to be cleared by software.  
Bit 4 = ENGC Enable General Call.  
This bit is set and cleared by software. It is also  
cleared by hardware when the interface is disa-  
bled (PE=0). The 00h General Call address is ac-  
knowledged (01h ignored).  
Bit 0 = ITE Interrupt enable.  
This bit is set and cleared by software and cleared  
by hardware when the interface is disabled  
(PE=0).  
0: General Call disabled  
1: General Call enabled  
0: Interrupts disabled  
1: Interrupts enabled  
Refer to Figure 45 for the relationship between the  
events and the interrupt.  
SCL is held low when the ADD10, SB, BTF or  
ADSL flags or an EV6 event (See Figure 44) is de-  
tected.  
Note: In accordance with the I2C standard, when  
GCAL addressing is enabled, an I2C slave can  
only receive data. It will not transmit data to the  
master.  
Bit 3 = START Generation of a Start condition.  
This bit is set and cleared by software. It is also  
cleared by hardware when the interface is disa-  
bled (PE=0) or when the Start condition is sent  
(with interrupt generation if ITE=1).  
– In master mode:  
0: No start generation  
1: Repeated start generation  
80/135  
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2
I C BUS INTERFACE (Cont’d)  
2
I C STATUS REGISTER 1 (SR1)  
tection of Stop condition (STOPF=1), loss of bus  
arbitration (ARLO=1) or when the interface is disa-  
bled (PE=0).  
0: Data byte received (if BTF=1)  
1: Data byte transmitted  
Read Only  
Reset Value: 0000 0000 (00h)  
7
0
EVF ADD10 TRA BUSY BTF ADSL M/SL SB  
Bit 4 = BUSY Bus busy.  
This bit is set by hardware on detection of a Start  
condition and cleared by hardware on detection of  
a Stop condition. It indicates a communication in  
progress on the bus. The BUSY flag of the I2CSR1  
register is cleared if a Bus Error occurs.  
0: No communication on the bus  
Bit 7 = EVF Event flag.  
This bit is set by hardware as soon as an event oc-  
curs. It is cleared by software reading SR2 register  
in case of error event or as described in Figure 44.  
It is also cleared by hardware when the interface is  
disabled (PE=0).  
1: Communication ongoing on the bus  
0: No event  
1: One of the following events has occurred:  
Bit 3 = BTF Byte transfer finished.  
This bit is set by hardware as soon as a byte is cor-  
rectly received or transmitted with interrupt gener-  
ation if ITE=1. It is cleared by software reading  
SR1 register followed by a read or write of DR reg-  
ister. It is also cleared by hardware when the inter-  
face is disabled (PE=0).  
– BTF=1 (Byte received or transmitted)  
– ADSL=1 (Address matched in Slave mode  
while ACK=1)  
– SB=1 (Start condition generated in Master  
mode)  
– AF=1 (No acknowledge received after byte  
transmission)  
– Following a byte transmission, this bit is set after  
reception of the acknowledge clock pulse. In  
case an address byte is sent, this bit is set only  
after the EV6 event (See Figure 44). BTF is  
cleared by reading SR1 register followed by writ-  
ing the next byte in DR register.  
– STOPF=1 (Stop condition detected in Slave  
mode)  
– ARLO=1 (Arbitration lost in Master mode)  
– BERR=1 (Bus error, misplaced Start or Stop  
condition detected)  
– Following a byte reception, this bit is set after  
transmission of the acknowledge clock pulse if  
ACK=1. BTF is cleared by reading SR1 register  
followed by reading the byte from DR register.  
– ADD10=1 (Master has sent header byte)  
– Address byte successfully transmitted in Mas-  
ter mode.  
The SCL line is held low while BTF=1.  
0: Byte transfer not done  
1: Byte transfer succeeded  
Bit 6 = ADD10 10-bit addressing in Master mode.  
This bit is set by hardware when the master has  
sent the first byte in 10-bit address mode. It is  
cleared by software reading SR2 register followed  
by a write in the DR register of the second address  
byte. It is also cleared by hardware when the pe-  
ripheral is disabled (PE=0).  
Bit 2 = ADSL Address matched (Slave mode).  
This bit is set by hardware as soon as the received  
slave address matched with the OAR register con-  
tent or a general call is recognized. An interrupt is  
generated if ITE=1. It is cleared by software read-  
ing SR1 register or by hardware when the inter-  
face is disabled (PE=0).  
0: No ADD10 event occurred.  
1: Master has sent first address byte (header)  
The SCL line is held low while ADSL=1.  
Bit 5 = TRA Transmitter/Receiver.  
0: Address mismatched or not received  
1: Received address matched  
When BTF is set, TRA=1 if a data byte has been  
transmitted. It is cleared automatically when BTF  
is cleared. It is also cleared by hardware after de-  
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I C BUS INTERFACE (Cont’d)  
Bit 1 = M/SL Master/Slave.  
This bit is set by hardware as soon as the interface  
Bit 2 = ARLO Arbitration lost.  
is in Master mode (writing START=1). It is cleared  
This bit is set by hardware when the interface los-  
by hardware after detecting a Stop condition on  
the bus or a loss of arbitration (ARLO=1). It is also  
cleared when the interface is disabled (PE=0).  
0: Slave mode  
es the arbitration of the bus to another master. An  
interrupt is generated if ITE=1. It is cleared by soft-  
ware reading SR2 register or by hardware when  
the interface is disabled (PE=0).  
1: Master mode  
After an ARLO event the interface switches back  
automatically to Slave mode (M/SL=0).  
Bit 0 = SB Start bit (Master mode).  
The SCL line is not held low while ARLO=1.  
This bit is set by hardware as soon as the Start  
condition is generated (following  
a
write  
0: No arbitration lost detected  
START=1). An interrupt is generated if ITE=1. It is  
cleared by software reading SR1 register followed  
by writing the address byte in DR register. It is also  
cleared by hardware when the interface is disa-  
bled (PE=0).  
1: Arbitration lost detected  
Note:  
– In a Multimaster environment, when the interface  
is configured in Master Receive mode it does not  
perform arbitration during the reception of the  
Acknowledge Bit. Mishandling of the ARLO bit  
from the I2CSR2 register may occur when a sec-  
ond master simultaneously requests the same  
0: No Start condition  
1: Start condition generated  
2
2
data from the same slave and the I C master  
does not acknowledge the data. The ARLO bit is  
then left at 0 instead of being set.  
I C STATUS REGISTER 2 (SR2)  
Read Only  
Reset Value: 0000 0000 (00h)  
7
0
Bit 1 = BERR Bus error.  
This bit is set by hardware when the interface de-  
tects a misplaced Start or Stop condition. An inter-  
rupt is generated if ITE=1. It is cleared by software  
reading SR2 register or by hardware when the in-  
terface is disabled (PE=0).  
0
0
0
AF STOPF ARLO BERR GCAL  
Bit 7:5 = Reserved. Forced to 0 by hardware.  
The SCL line is not held low while BERR=1.  
0: No misplaced Start or Stop condition  
1: Misplaced Start or Stop condition  
Note:  
– If a Bus Error occurs, a Stop or a repeated Start  
condition should be generated by the Master to  
re-synchronize communication, get the transmis-  
sion acknowledged and the bus released for fur-  
ther communication  
Bit 4 = AF Acknowledge failure.  
This bit is set by hardware when no acknowledge  
is returned. An interrupt is generated if ITE=1. It is  
cleared by software reading SR2 register or by  
hardware when the interface is disabled (PE=0).  
The SCL line is not held low while AF=1 but by oth-  
er flags (SB or BTF) that are set at the same time.  
0: No acknowledge failure  
1: Acknowledge failure  
Bit 0 = GCAL General Call (Slave mode).  
This bit is set by hardware when a general call ad-  
dress is detected on the bus while ENGC=1. It is  
cleared by hardware detecting a Stop condition  
(STOPF=1) or when the interface is disabled  
(PE=0).  
Bit 3 = STOPF Stop detection (Slave mode).  
This bit is set by hardware when a Stop condition  
is detected on the bus after an acknowledge (if  
ACK=1). An interrupt is generated if ITE=1. It is  
cleared by software reading SR2 register or by  
hardware when the interface is disabled (PE=0).  
0: No general call address detected on bus  
1: general call address detected on bus  
The SCL line is not held low while STOPF=1.  
0: No Stop condition detected  
1: Stop condition detected  
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2
I C BUS INTERFACE (Cont’d)  
2
2
I C CLOCK CONTROL REGISTER (CCR)  
I C OWN ADDRESS REGISTER (OAR1)  
Read / Write  
Reset Value: 0000 0000 (00h)  
Read / Write  
Reset Value: 0000 0000 (00h)  
7
0
7
0
FM/SM CC6 CC5 CC4 CC3 CC2 CC1 CC0  
ADD7 ADD6 ADD5 ADD4 ADD3 ADD2 ADD1 ADD0  
2
Bit 7 = FM/SM Fast/Standard I C mode.  
7-bit Addressing Mode  
This bit is set and cleared by software. It is not  
cleared when the interface is disabled (PE=0).  
Bit 7:1 = ADD[7:1] Interface address.  
2
These bits define the I C bus address of the inter-  
2
0: Standard I C mode  
face. They are not cleared when the interface is  
disabled (PE=0).  
2
1: Fast I C mode  
Bit 6:0 = CC[6:0] 7-bit clock divider.  
These bits select the speed of the bus (f  
pending on the I C mode. They are not cleared  
when the interface is disabled (PE=0).  
Bit 0 = ADD0 Address direction bit.  
This bit is don’t care, the interface acknowledges  
either 0 or 1. It is not cleared when the interface is  
disabled (PE=0).  
) de-  
SCL  
2
Refer to the Electrical Characteristics section for  
the table of values.  
Note: Address 01h is always ignored.  
10-bit Addressing Mode  
Note: The programmed f  
assumes no load on  
SCL  
Bit 7:0 = ADD[7:0] Interface address.  
These are the least significant bits of the I C bus  
SCL and SDA lines.  
2
address of the interface. They are not cleared  
when the interface is disabled (PE=0).  
2
I C DATA REGISTER (DR)  
Read / Write  
Reset Value: 0000 0000 (00h)  
2
I C OWN ADDRESS REGISTER (OAR2)  
7
0
D0  
Read / Write  
Reset Value: 0100 0000 (40h)  
D7  
D6  
D5  
D4  
D3  
D2  
D1  
7
0
0
Bit 7:0 = D[7:0] 8-bit Data Register.  
FR1 FR0  
0
0
0
ADD9 ADD8  
These bits contain the byte to be received or trans-  
mitted on the bus.  
Bit 7:6 = FR[1:0] Frequency bits.  
– Transmitter mode: Byte transmission start auto-  
matically when the software writes in the DR reg-  
ister.  
These bits are set by software only when the inter-  
face is disabled (PE=0). To configure the interface  
2
to I C specified delays select the value corre-  
– Receiver mode: the first data byte is received au-  
tomatically in the DR register using the least sig-  
nificant bit of the address.  
Then, the following data bytes are received one  
by one after reading the DR register.  
sponding to the microcontroller frequency f  
.
CPU  
f
FR1  
0
FR0  
0
CPU  
< 6 MHz  
6 to 8 MHz  
0
1
Bit 5:3 = Reserved  
Bit 2:1 = ADD[9:8] Interface address.  
2
These are the most significant bits of the I C bus  
address of the interface (10-bit mode only). They  
are not cleared when the interface is disabled  
(PE=0).  
Bit 0 = Reserved.  
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2
Table 17. I C Register Map and Reset Values  
Address  
(Hex.)  
Register  
Label  
7
6
5
4
3
2
1
0
I2CCR  
Reset Value  
PE  
0
ENGC  
0
START  
0
ACK  
0
STOP  
0
ITE  
0
0028h  
0029h  
002Ah  
02Bh  
0
0
I2CSR1  
Reset Value  
EVF  
0
ADD10  
0
TRA  
0
BUSY  
0
BTF  
0
ADSL  
0
M/SL  
0
SB  
0
I2CSR2  
Reset Value  
AF  
0
STOPF  
0
ARLO  
0
BERR  
0
GCAL  
0
0
0
0
I2CCCR  
Reset Value  
FM/SM  
0
CC6  
0
CC5  
0
CC4  
0
CC3  
0
CC2  
0
CC1  
0
CC0  
0
I2COAR1  
Reset Value  
ADD7  
0
ADD6  
0
ADD5  
0
ADD4  
0
ADD3  
0
ADD2  
0
ADD1  
0
ADD0  
0
02Ch  
I2COAR2  
Reset Value  
FR1  
0
FR0  
1
ADD9  
0
ADD8  
0
002Dh  
002Eh  
0
0
0
0
0
0
0
I2CDR  
Reset Value  
MSB  
0
LSB  
0
0
0
0
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11.5 8-BIT A/D CONVERTER (ADC)  
11.5.1 Introduction  
11.5.3 Functional Description  
11.5.3.1 Analog Power Supply  
The on-chip Analog to Digital Converter (ADC) pe-  
ripheral is an 8-bit, successive approximation con-  
verter with internal sample and hold circuitry. This  
peripheral has up to 16 multiplexed analog input  
channels (refer to device pinout description) that  
allow the peripheral to convert the analog voltage  
levels from up to 16 different sources.  
V
and V  
are the high and low level refer-  
SSA  
DDA  
ence voltage pins. In some devices (refer to device  
pinout description) they are internally connected to  
the V and V pins.  
DD  
SS  
Conversion accuracy may therefore be impacted  
by voltage drops and noise in the event of heavily  
loaded or badly decoupled power supply lines.  
The result of the conversion is stored in an 8-bit  
Data Register. The A/D converter is controlled  
through a Control/Status Register.  
See electrical characteristics section for more de-  
tails.  
11.5.2 Main Features  
8-bit conversion  
Up to 16 channels with multiplexed input  
Linear successive approximation  
Data register (DR) which contains the results  
Conversion complete status flag  
On/off bit (to reduce consumption)  
The block diagram is shown in Figure 46.  
Figure 46. ADC Block Diagram  
f
f
ADC  
CPU  
DIV 2  
COCO  
0
ADON  
4
0
CH3 CH2 CH1 CH0  
ADCCSR  
AIN0  
AIN1  
HOLD CONTROL  
R
ADC  
ANALOG TO DIGITAL  
CONVERTER  
ANALOG  
MUX  
AINx  
C
ADC  
ADCDR  
D7  
D6  
D5  
D4  
D3  
D2  
D1  
D0  
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8-BIT A/D CONVERTER (ADC) (Cont’d)  
11.5.3.2 Digital A/D Conversion Result  
The analog input ports must be configured as in-  
put, no pull-up, no interrupt. Refer to the “I/O ports”  
chapter. Using these pins as analog inputs does  
not affect the ability of the port to be read as a logic  
input.  
The conversion is monotonic, meaning that the re-  
sult never decreases if the analog input does not  
and never increases if the analog input does not.  
If the input voltage (V ) is greater than or equal  
AIN  
In the CSR register:  
to V  
(high-level voltage reference) then the  
DDA  
conversion result in the DR register is FFh (full  
scale) without overflow indication.  
– Select the CH[3:0] bits to assign the analog  
channel to be converted.  
ADC Conversion  
If input voltage (V ) is lower than or equal to  
AIN  
V
(low-level voltage reference) then the con-  
SSA  
In the CSR register:  
version result in the DR register is 00h.  
– Set the ADON bit to enable the A/D converter  
and to start the first conversion. From this time  
on, the ADC performs a continuous conver-  
sion of the selected channel.  
The A/D converter is linear and the digital result of  
the conversion is stored in the ADCDR register.  
The accuracy of the conversion is described in the  
parametric section.  
When a conversion is complete  
R
is the maximum recommended impedance  
– The COCO bit is set by hardware.  
– No interrupt is generated.  
AIN  
for an analog input signal. If the impedance is too  
high, this will result in a loss of accuracy due to  
leakage and sampling not being completed in the  
allotted time.  
– The result is in the DR register and remains  
valid until the next conversion has ended.  
A write to the CSR register (with ADON set) aborts  
the current conversion, resets the COCO bit and  
starts a new conversion.  
11.5.3.3 A/D Conversion Phases  
The A/D conversion is based on two conversion  
phases as shown in Figure 47:  
Sample capacitor loading [duration: t  
Figure 47. ADC Conversion Timings  
]
LOAD  
During this phase, the V  
input voltage to be  
AIN  
ADON  
measured is loaded into the C  
capacitor.  
sample  
ADC  
ADCCSR WRITE  
OPERATION  
t
CONV  
A/D conversion [duration: t  
]
CONV  
During this phase, the A/D conversion is  
computed (8 successive approximations cycles)  
HOLD  
CONTROL  
and the C  
sample capacitor is disconnected  
ADC  
from the analog input pin to get the optimum  
analog to digital conversion accuracy.  
t
LOAD  
COCO BIT SET  
While the ADC is on, these two phases are contin-  
uously repeated.  
11.5.4 Low Power Modes  
At the end of each conversion, the sample capaci-  
tor is kept loaded with the previous measurement  
load. The advantage of this behavior is that it min-  
imizes the current consumption on the analog pin  
in case of single input channel measurement.  
Mode  
Description  
No effect on A/D Converter  
WAIT  
A/D Converter disabled.  
After wake-up from Halt mode, the A/D Con-  
verter requires a stabilization time before ac-  
curate conversions can be performed.  
HALT  
11.5.3.4 Software Procedure  
Refer to the control/status register (CSR) and data  
register (DR) in Section 11.5.6 for the bit defini-  
tions and to Figure 47 for the timings.  
Note: The A/D converter may be disabled by reset-  
ting the ADON bit. This feature allows reduced  
power consumption when no conversion is needed  
and between single shot conversions.  
ADC Configuration  
The total duration of the A/D conversion is 12 ADC  
11.5.5 Interrupts  
clock periods (1/f  
=2/f  
).  
ADC  
CPU  
None  
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8-BIT A/D CONVERTER (ADC) (Cont’d)  
11.5.6 Register Description  
CONTROL/STATUS REGISTER (CSR)  
Read/Write  
DATA REGISTER (DR)  
Read Only  
Reset Value: 0000 0000 (00h)  
Reset Value: 0000 0000 (00h)  
7
0
7
0
COCO  
0
ADON  
0
CH3 CH2 CH1 CH0  
D7  
D6  
D5  
D4  
D3  
D2  
D1  
D0  
Bit 7 = COCO Conversion Complete  
This bit is set by hardware. It is cleared by soft-  
ware reading the result in the DR register or writing  
to the CSR register.  
Bits 7:0 = D[7:0] Analog Converted Value  
This register contains the converted analog value  
in the range 00h to FFh.  
0: Conversion is not complete  
Note: Reading this register reset the COCO flag.  
1: Conversion can be read from the DR register  
Bit 6 = Reserved. must always be cleared.  
Bit 5 = ADON A/D Converter On  
This bit is set and cleared by software.  
0: A/D converter is switched off  
1: A/D converter is switched on  
Bit 4 = Reserved. must always be cleared.  
Bits 3:0 = CH[3:0] Channel Selection  
These bits are set and cleared by software. They  
select the analog input to convert.  
Channel Pin*  
CH3 CH2 CH1 CH0  
AIN0  
AIN1  
AIN2  
AIN3  
AIN4  
AIN5  
AIN6  
AIN7  
AIN8  
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
AIN9  
AIN10  
AIN11  
AIN12  
AIN13  
AIN14  
AIN15  
*Note: The number of pins AND the channel selec-  
tion varies according to the device. Refer to the de-  
vice pinout.  
87/135  
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
8-BIT A/D CONVERTER (ADC) (Cont’d)  
Table 18. ADC Register Map and Reset Values  
Address  
(Hex.)  
Register  
Label  
7
6
5
4
3
2
1
0
ADCDR  
Reset Value  
D7  
0
D6  
0
D5  
0
D4  
0
D3  
0
D2  
0
D1  
0
D0  
0
0070h  
0071h  
ADCCSR  
Reset Value  
COCO  
0
ADON  
0
CH3  
0
CH2  
0
CH1  
0
CH0  
0
0
0
88/135  
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
12 INSTRUCTION SET  
12.1 ST7 ADDRESSING MODES  
so, most of the addressing modes may be subdi-  
vided in two submodes called long and short:  
The ST7 Core features 17 different addressing  
modes which can be classified in 7 main groups:  
– Long addressing mode is more powerful be-  
cause it can use the full 64 Kbyte address space,  
however it uses more bytes and more CPU cy-  
cles.  
Addressing Mode  
Inherent  
Example  
nop  
– Short addressing mode is less powerful because  
it can generally only access page zero (0000h -  
00FFh range), but the instruction size is more  
compact, and faster. All memory to memory in-  
structions use short addressing modes only  
(CLR, CPL, NEG, BSET, BRES, BTJT, BTJF,  
INC, DEC, RLC, RRC, SLL, SRL, SRA, SWAP)  
Immediate  
Direct  
ld A,#$55  
ld A,$55  
ld A,($55,X)  
ld A,([$55],X)  
jrne loop  
Indexed  
Indirect  
Relative  
Bit operation  
bset byte,#5  
The ST7 Assembler optimizes the use of long and  
short addressing modes.  
The ST7 Instruction set is designed to minimize  
the number of bytes required per instruction: To do  
Table 19. ST7 Addressing Mode Overview  
Pointer  
Address  
(Hex.)  
Pointer  
Size  
(Hex.)  
Destination/  
Source  
Length  
(bytes)  
Mode  
Syntax  
Inherent  
Immediate  
Short  
nop  
+ 0  
+ 1  
+ 1  
+ 2  
ld A,#$55  
ld A,$10  
Direct  
Direct  
00..FF  
Long  
ld A,$1000  
0000..FFFF  
+ 0 (with X register)  
+ 1 (with Y register)  
No Offset  
Direct  
Indexed  
ld A,(X)  
00..FF  
Short  
Long  
Short  
Long  
Short  
Long  
Relative  
Relative  
Bit  
Direct  
Indexed  
Indexed  
ld A,($10,X)  
ld A,($1000,X)  
ld A,[$10]  
00..1FE  
+ 1  
+ 2  
+ 2  
+ 2  
+ 2  
+ 2  
+ 1  
+ 2  
+ 1  
+ 2  
+ 2  
+ 3  
Direct  
0000..FFFF  
00..FF  
Indirect  
Indirect  
Indirect  
Indirect  
Direct  
00..FF  
00..FF  
00..FF  
00..FF  
byte  
word  
byte  
word  
ld A,[$10.w]  
ld A,([$10],X)  
0000..FFFF  
00..1FE  
Indexed  
Indexed  
ld A,([$10.w],X) 0000..FFFF  
1)  
1)  
jrne loop  
PC-128/PC+127  
Indirect  
Direct  
jrne [$10]  
PC-128/PC+127  
00..FF  
00..FF  
00..FF  
00..FF  
byte  
byte  
byte  
bset $10,#7  
bset [$10],#7  
Bit  
Indirect  
Direct  
00..FF  
Bit  
Relative btjt $10,#7,skip 00..FF  
Relative btjt [$10],#7,skip 00..FF  
Bit  
Indirect  
Notes:  
1. At the time the instruction is executed, the Program Counter (PC) points to the instruction following JRxx.  
89/135  
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
ST7 ADDRESSING MODES (Cont’d)  
12.1.1 Inherent  
12.1.3 Direct  
All Inherent instructions consist of a single byte.  
The opcode fully specifies all the required informa-  
tion for the CPU to process the operation.  
In Direct instructions, the operands are referenced  
by their memory address.  
The direct addressing mode consists of two sub-  
modes:  
Inherent Instruction  
Function  
No operation  
Direct (short)  
NOP  
The address is a byte, thus requires only one byte  
after the opcode, but only allows 00 - FF address-  
ing space.  
TRAP  
S/W Interrupt  
Wait For Interrupt (Low Power  
Mode)  
WFI  
Direct (long)  
Halt Oscillator (Lowest Power  
Mode)  
HALT  
The address is a word, thus allowing 64 Kbyte ad-  
dressing space, but requires 2 bytes after the op-  
code.  
RET  
Sub-routine Return  
Interrupt Sub-routine Return  
Set Interrupt Mask  
Reset Interrupt Mask  
Set Carry Flag  
IRET  
12.1.4 Indexed (No Offset, Short, Long)  
SIM  
In this mode, the operand is referenced by its  
memory address, which is defined by the unsigned  
addition of an index register (X or Y) with an offset.  
RIM  
SCF  
The indexed addressing mode consists of three  
submodes:  
RCF  
Reset Carry Flag  
Reset Stack Pointer  
Load  
RSP  
Indexed (No Offset)  
LD  
There is no offset, (no extra byte after the opcode),  
and allows 00 - FF addressing space.  
CLR  
Clear  
PUSH/POP  
INC/DEC  
TNZ  
Push/Pop to/from the stack  
Increment/Decrement  
Test Negative or Zero  
1 or 2 Complement  
Byte Multiplication  
Indexed (Short)  
The offset is a byte, thus requires only one byte af-  
ter the opcode and allows 00 - 1FE addressing  
space.  
CPL, NEG  
MUL  
Indexed (long)  
The offset is a word, thus allowing 64 Kbyte ad-  
dressing space and requires 2 bytes after the op-  
code.  
SLL, SRL, SRA, RLC,  
RRC  
Shift and Rotate Operations  
Swap Nibbles  
SWAP  
12.1.5 Indirect (Short, Long)  
12.1.2 Immediate  
The required data byte to do the operation is found  
by its memory address, located in memory (point-  
er).  
Immediate instructions have two bytes, the first  
byte contains the opcode, the second byte con-  
tains the operand value.  
The pointer address follows the opcode. The indi-  
rect addressing mode consists of two submodes:  
Immediate Instruction  
Function  
Indirect (short)  
LD  
Load  
The pointer address is a byte, the pointer size is a  
byte, thus allowing 00 - FF addressing space, and  
requires 1 byte after the opcode.  
CP  
Compare  
BCP  
Bit Compare  
AND, OR, XOR  
ADC, ADD, SUB, SBC  
Logical Operations  
Arithmetic Operations  
Indirect (long)  
The pointer address is a byte, the pointer size is a  
word, thus allowing 64 Kbyte addressing space,  
and requires 1 byte after the opcode.  
90/135  
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
ST7 ADDRESSING MODES (Cont’d)  
12.1.6 Indirect Indexed (Short, Long)  
12.1.7 Relative Mode (Direct, Indirect)  
This is a combination of indirect and short indexed  
addressing modes. The operand is referenced by  
its memory address, which is defined by the un-  
signed addition of an index register value (X or Y)  
with a pointer value located in memory. The point-  
er address follows the opcode.  
This addressing mode is used to modify the PC  
register value by adding an 8-bit signed offset to it.  
Available Relative Direct/  
Function  
Indirect Instructions  
JRxx  
Conditional Jump  
Call Relative  
The indirect indexed addressing mode consists of  
two submodes:  
CALLR  
The relative addressing mode consists of two sub-  
modes:  
Indirect Indexed (Short)  
The pointer address is a byte, the pointer size is a  
byte, thus allowing 00 - 1FE addressing space,  
and requires 1 byte after the opcode.  
Relative (Direct)  
The offset follows the opcode.  
Relative (Indirect)  
Indirect Indexed (Long)  
The pointer address is a byte, the pointer size is a  
word, thus allowing 64 Kbyte addressing space,  
and requires 1 byte after the opcode.  
The offset is defined in memory, of which the ad-  
dress follows the opcode.  
Table 20. Instructions Supporting Direct,  
Indexed, Indirect and Indirect Indexed  
Addressing Modes  
Long and Short  
Function  
Instructions  
LD  
Load  
CP  
Compare  
AND, OR, XOR  
Logical Operations  
Arithmetic Addition/subtrac-  
tion operations  
ADC, ADD, SUB, SBC  
BCP  
Bit Compare  
Short Instructions Only  
CLR  
Function  
Clear  
INC, DEC  
Increment/Decrement  
Test Negative or Zero  
1 or 2 Complement  
Bit Operations  
TNZ  
CPL, NEG  
BSET, BRES  
Bit Test and Jump Opera-  
tions  
BTJT, BTJF  
SLL, SRL, SRA, RLC,  
RRC  
Shift and Rotate Operations  
SWAP  
Swap Nibbles  
CALL, JP  
Call or Jump subroutine  
91/135  
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
12.2 INSTRUCTION GROUPS  
The ST7 family devices use an Instruction Set  
consisting of 63 instructions. The instructions may  
be subdivided into 13 main groups as illustrated in  
the following table:  
Load and Transfer  
LD  
CLR  
POP  
DEC  
TNZ  
OR  
Stack operation  
PUSH  
INC  
RSP  
BCP  
Increment/Decrement  
Compare and Tests  
Logical operations  
CP  
AND  
BSET  
BTJT  
ADC  
SLL  
XOR  
CPL  
NEG  
Bit Operation  
BRES  
BTJF  
ADD  
SRL  
JRT  
Conditional Bit Test and Branch  
Arithmetic operations  
Shift and Rotates  
SUB  
SRA  
JRF  
SBC  
RLC  
JP  
MUL  
RRC  
CALL  
SWAP  
CALLR  
SLA  
Unconditional Jump or Call  
Conditional Branch  
JRA  
JRxx  
TRAP  
SIM  
NOP  
RET  
Interruption management  
Condition Code Flag modification  
WFI  
RIM  
HALT  
SCF  
IRET  
RCF  
Using a prebyte  
The instructions are described with one to four  
bytes.  
These prebytes enable instruction in Y as well as  
indirect addressing modes to be implemented.  
They precede the opcode of the instruction in X or  
the instruction using direct addressing mode. The  
prebytes are:  
In order to extend the number of available op-  
codes for an 8-bit CPU (256 opcodes), three differ-  
ent prebyte opcodes are defined. These prebytes  
modify the meaning of the instruction they pre-  
cede.  
PDY 90 Replace an X based instruction using  
immediate, direct, indexed, or inherent  
addressing mode by a Y one.  
The whole instruction becomes:  
PC-2 End of previous instruction  
PC-1 Prebyte  
PIX 92 Replace an instruction using direct, di-  
rect bit, or direct relative addressing  
mode to an instruction using the corre-  
sponding indirect addressing mode.  
It also changes an instruction using X  
indexed addressing mode to an instruc-  
tion using indirect X indexed addressing  
mode.  
PC  
Opcode  
PC+1 Additional word (0 to 2) according to the  
number of bytes required to compute the  
effective address  
PIY 91 Replace an instruction using X indirect  
indexed addressing mode by a Y one.  
92/135  
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
INSTRUCTION GROUPS (Cont’d)  
Mnemo  
ADC  
ADD  
AND  
BCP  
Description  
Add with Carry  
Function/Example  
A = A + M + C  
A = A + M  
Dst  
Src  
H
H
H
I
N
N
N
N
N
Z
Z
Z
Z
Z
C
C
C
A
M
M
M
M
Addition  
A
Logical And  
A = A . M  
A
Bit compare A, Memory  
Bit Reset  
tst (A . M)  
A
BRES  
BSET  
BTJF  
BTJT  
CALL  
CALLR  
CLR  
bres Byte, #3  
bset Byte, #3  
btjf Byte, #3, Jmp1  
btjt Byte, #3, Jmp1  
M
M
M
M
Bit Set  
Jump if bit is false (0)  
Jump if bit is true (1)  
Call subroutine  
Call subroutine relative  
Clear  
C
C
reg, M  
reg  
0
N
N
N
1
Z
Z
Z
CP  
Arithmetic Compare  
One Complement  
Decrement  
tst(Reg - M)  
A = FFH-A  
dec Y  
M
C
1
CPL  
reg, M  
reg, M  
DEC  
HALT  
IRET  
INC  
Halt  
0
I
Interrupt routine return  
Increment  
Pop CC, A, X, PC  
inc X  
H
N
N
Z
Z
C
reg, M  
JP  
Absolute Jump  
Jump relative always  
Jump relative  
jp [TBL.w]  
JRA  
JRT  
JRF  
Never jump  
jrf *  
JRIH  
JRIL  
Jump if ext. interrupt = 1  
Jump if ext. interrupt = 0  
Jump if H = 1  
JRH  
H = 1 ?  
JRNH  
JRM  
Jump if H = 0  
H = 0 ?  
Jump if I = 1  
I = 1 ?  
JRNM  
JRMI  
JRPL  
JREQ  
JRNE  
JRC  
Jump if I = 0  
I = 0 ?  
Jump if N = 1 (minus)  
Jump if N = 0 (plus)  
Jump if Z = 1 (equal)  
Jump if Z = 0 (not equal)  
Jump if C = 1  
N = 1 ?  
N = 0 ?  
Z = 1 ?  
Z = 0 ?  
C = 1 ?  
JRNC  
JRULT  
Jump if C = 0  
C = 0 ?  
Jump if C = 1  
Unsigned <  
Jmp if unsigned >=  
Unsigned >  
JRUGE Jump if C = 0  
JRUGT Jump if (C + Z = 0)  
93/135  
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
INSTRUCTION GROUPS (Cont’d)  
Mnemo  
JRULE  
LD  
Description  
Jump if (C + Z = 1)  
Load  
Function/Example  
Unsigned <=  
dst <= src  
Dst  
Src  
H
I
N
N
N
N
N
Z
Z
Z
Z
Z
C
reg, M  
A, X, Y  
reg, M  
M, reg  
X, Y, A  
MUL  
NEG  
NOP  
OR  
Multiply  
X,A = X * A  
0
0
Negate (2's compl)  
No Operation  
OR operation  
Pop from the Stack  
neg $10  
C
A = A + M  
pop reg  
pop CC  
push Y  
C = 0  
A
M
POP  
reg  
CC  
M
M
M
H
I
C
0
PUSH  
RCF  
RET  
RIM  
Push onto the Stack  
Reset carry flag  
Subroutine Return  
Enable Interrupts  
Rotate left true C  
Rotate right true C  
Reset Stack Pointer  
Subtract with Carry  
Set carry flag  
reg, CC  
I = 0  
0
RLC  
RRC  
RSP  
SBC  
SCF  
SIM  
C <= Dst <= C  
C => Dst => C  
S = Max allowed  
A = A - M - C  
C = 1  
reg, M  
reg, M  
N
N
Z
Z
C
C
A
M
N
Z
C
1
Disable Interrupts  
Shift left Arithmetic  
Shift left Logic  
I = 1  
1
SLA  
C <= Dst <= 0  
C <= Dst <= 0  
0 => Dst => C  
Dst7 => Dst => C  
A = A - M  
reg, M  
reg, M  
reg, M  
reg, M  
A
N
N
0
Z
Z
Z
Z
Z
Z
Z
C
C
C
C
C
SLL  
SRL  
SRA  
SUB  
SWAP  
TNZ  
TRAP  
WFI  
Shift right Logic  
Shift right Arithmetic  
Subtraction  
N
N
N
N
M
M
SWAP nibbles  
Dst[7..4] <=> Dst[3..0] reg, M  
tnz lbl1  
Test for Neg & Zero  
S/W trap  
S/W interrupt  
1
0
Wait for Interrupt  
Exclusive OR  
XOR  
A = A XOR M  
A
N
Z
94/135  
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
13 ELECTRICAL CHARACTERISTICS  
13.1 PARAMETER CONDITIONS  
Unless otherwise specified, all voltages are re-  
13.1.5 Pin Input Voltage  
ferred to V  
.
SS  
The input voltage measurement on a pin of the de-  
vice is described in Figure 49.  
13.1.1 Minimum and Maximum Values  
Unless otherwise specified the minimum and max-  
imum values are guaranteed in the worst condi-  
tions of ambient temperature, supply voltage and  
frequencies by tests in production on 100% of the  
Figure 49. Pin Input Voltage  
devices with an ambient temperature at T =25°C  
A
ST7 PIN  
and T =T max (given by the selected temperature  
A
A
range).  
V
Data based on characterization results, design  
simulation and/or technology characteristics are  
indicated in the table footnotes and are not tested  
in production. Based on characterization, the min-  
imum and maximum values refer to sample tests  
and represent the mean value plus or minus three  
times the standard deviation (mean 3Σ).  
IN  
13.1.2 Typical Values  
Unless otherwise specified, typical data are based  
on T =25°C, V =5V (for the 4.5VV 5.5V  
A
DD  
DD  
DD  
voltage range) and V =3.3V (for the 3VV 4V  
DD  
voltage range). They are given only as design  
guidelines and are not tested.  
13.1.3 Typical Curves  
Unless otherwise specified, all typical curves are  
given only as design guidelines and are not tested.  
13.1.4 Loading Capacitor  
The loading conditions used for pin parameter  
measurement are shown in Figure 48.  
Figure 48. Pin Loading Conditions  
ST7 PIN  
C
L
95/135  
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
13.2 ABSOLUTE MAXIMUM RATINGS  
Stresses above those listed as “absolute maxi-  
mum ratings” may cause permanent damage to  
the device. This is a stress rating only and func-  
tional operation of the device under these condi-  
tions is not implied. Exposure to maximum rating  
conditions for extended periods may affect device  
reliability.  
13.2.1 Voltage Characteristics  
Symbol  
Ratings  
Maximum value  
Unit  
V
- V  
Supply voltage  
6.5  
DD  
SS  
1) & 2)  
Input voltage on true open drain pin  
V
-0.3 to 6.5  
V
SS  
V
IN  
Input voltage on any other pin  
V
-0.3 to V +0.3  
SS DD  
V
Electrostatic discharge voltage (Human Body Model)  
Electrostatic discharge voltage (Machine Model)  
see Section 13.7.2 "Absolute Elec-  
trical Sensitivity" on page 112  
ESD(HBM)  
V
ESD(MM)  
13.2.2 Current Characteristics  
Symbol  
Ratings  
Maximum value  
Unit  
3)  
3)  
Total current into V power lines (source)  
80  
80  
25  
50  
- 25  
5
I
DD  
VDD  
Total current out of V ground lines (sink)  
I
SS  
VSS  
Output current sunk by any standard I/O and control pin  
Output current sunk by any high sink I/O pin  
Output current source by any I/Os and control pin  
Injected current on ISPSEL pin  
I
IO  
mA  
Injected current on RESET pin  
5
2) & 4)  
2)  
I
INJ(PIN)  
Injected current on OSC1 and OSC2 pins  
5
5) & 6)  
Injected current on any other pin  
5
5)  
Total injected current (sum of all I/O and control pins)  
20  
ΣI  
INJ(PIN)  
13.2.3 Thermal Characteristics  
Symbol  
Ratings  
Value  
Unit  
T
Storage temperature range  
Maximum junction temperature  
(see Section 14.3 "THERMAL CHARACTERISTICS" on page 128)  
-65 to +150  
°C  
STG  
T
J
Notes:  
1. Directly connecting the RESET and I/O pins to V or V could damage the device if an unintentional internal reset  
DD  
SS  
is generated or an unexpected change of the I/O configuration occurs (for example, due to a corrupted program counter).  
To guarantee safe operation, this connection has to be done through a pull-up or pull-down resistor (typical: 4.7kfor  
RESET, 10kfor I/Os). Unused I/O pins must be tied in the same way to V or V according to their reset configuration.  
DD  
SS  
2. When the current limitation is not possible, the V absolute maximum rating must be respected, otherwise refer to  
IN  
I
specification. A positive injection is induced by V >V while a negative injection is induced by V <V  
.
SS  
INJ(PIN)  
IN  
DD  
IN  
3. All power (V ) and ground (V ) lines must always be connected to the external supply.  
DD  
SS  
4. Negative injection disturbs the analog performance of the device. In particular, it induces leakage currents throughout  
the device including the analog inputs. To avoid undesirable effects on the analog functions, care must be taken:  
- Analog input pins must have a negative injection less than 0.8 mA (assuming that the impedance of the analog voltage  
is lower than the specified limits)  
- Pure digital pins must have a negative injection less than 1.6mA. In addition, it is recommended to inject the current as  
far as possible from the analog input pins.  
5. When several inputs are submitted to a current injection, the maximum ΣI  
is the absolute sum of the positive  
INJ(PIN)  
and negative injected currents (instantaneous values). These results are based on characterization with ΣI  
maxi-  
INJ(PIN)  
mum current injection on four I/O port pins of the device.  
6. True open drain I/O port pins do not accept positive injection.  
96/135  
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
13.3 OPERATING CONDITIONS  
13.3.1 General Operating Conditions  
Symbol  
Parameter  
Supply voltage  
Conditions  
Min  
Max  
Unit  
V
see Figure 50 and Figure 51  
3.2  
5.5  
V
DD  
V
V
3.5V for ROM devices  
4.5V for Flash devices  
DD  
DD  
16  
1)  
f
External clock frequency  
0
MHz  
OSC  
V
3.2V  
8
DD  
Suffix A version  
Suffix B version  
Suffix C version  
+85  
T
Ambient temperature range  
-40  
+105  
+125  
°C  
2)  
A
Figure 50. f  
Maximum Operating Frequency Versus V Supply Voltage for ROM Devices  
DD  
OSC  
f
[MHz]  
FUNCTIONALITY  
GUARANTEED  
IN THIS AREA  
OSC  
16  
FUNCTIONALITY  
NOT GUARANTEED  
IN THIS AREA  
FUNCTIONALITY  
NOT GUARANTEED  
IN THIS AREA  
8
4
1)  
WITH RESONATOR  
1
0
SUPPLY VOLTAGE [V]  
2.5  
3.2  
3.5  
3.85 4  
4.5  
5
5.5  
97/135  
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
OPERATING CONDITIONS (Cont’d)  
2)  
Figure 51. f  
Maximum Operating Frequency Versus V Supply Voltage for Flash devices  
OSC  
DD  
FUNCTIONALITY  
NOT GUARANTEED  
f
[MHz]  
IN THIS AREA AT T > 85°C  
FUNCTIONALITY  
GUARANTEED  
OSC  
A
3)  
IN THIS AREA  
16  
FUNCTIONALITY  
NOT GUARANTEED  
IN THIS AREA  
12  
8
FUNCTIONALITY  
NOT GUARANTEED  
IN THIS AREA  
1)  
WITH RESONATOR  
4
1
0
SUPPLY VOLTAGE [V]  
2.5  
3.2  
3.5  
3.85  
4
4.5  
5
5.5  
Notes:  
1. Guaranteed by construction. A/D operation and resonator oscillator start-up are not guaranteed below 1MHz.  
2. Operating conditions with T =-40 to +125°C.  
A
3. Flash programming tested in production at maximum T with two different conditions: V =5.5V, f =8MHz and  
A
DD  
CPU  
V
=3.2V, f  
=4MHz.  
CPU  
DD  
98/135  
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
OPERATING CONDITIONS (Cont’d)  
13.3.2 Operating Conditions with Low Voltage Detector (LVD)  
Subject to general operating conditions for V , f , and T .  
DD OSC  
Conditions  
High Threshold  
Med. Threshold  
Low Threshold  
A
1)  
Symbol  
Parameter  
Min  
Typ  
Max  
Unit  
2)  
4.10  
3.75  
3.25  
4.30  
3.90  
3.35  
4.50  
4.05  
3.55  
Reset release threshold  
2)  
2)  
V
IT+  
(V rise)  
DD  
V
2)  
2)  
High Threshold  
Med. Threshold  
3.85  
3.50  
4.05  
3.65  
3.10  
4.30  
3.95  
3.35  
Reset generation threshold  
V
V
IT-  
(V fall)  
4)  
DD  
Low Threshold  
3.00  
200  
0.2  
LVD voltage threshold hysteresis  
V
-V  
250  
300  
50  
mV  
V/ms  
ns  
hyst  
IT+ IT-  
3)  
Vt  
V
rise time rate  
DD  
POR  
2)  
t
Filtered glitch delay on V  
Not detected by the LVD  
40  
g(VDD)  
DD  
3)  
Figure 52. High LVD Threshold Versus V and f  
for Flash devices  
OSC  
DD  
FUNCTIONALITY AND RESET NOT GUARANTEED IN THIS AREA  
FOR TEMPERATURES HIGHER THAN 85°C  
f
[MHz]  
FUNCTIONALITY  
NOT GUARANTEED  
IN THIS AREA  
OSC  
16  
DEVICE UNDER  
RESET  
12  
IN THIS AREA  
FUNCTIONAL AREA  
8
0
SUPPLY VOLTAGE [V]  
V
3.85  
IT-  
2.5  
3
3.5  
4
4.5  
5
5.5  
3)  
Figure 53. Medium LVD Threshold Versus V and f  
for Flash devices  
DD  
OSC  
FUNCTIONALITY AND RESET NOT GUARANTEED IN THIS AREA  
FOR TEMPERATURES HIGHER THAN 85°C  
f
[MHz]  
FUNCTIONALITY  
NOT GUARANTEED  
IN THIS AREA  
OSC  
16  
DEVICE UNDER  
RESET  
12  
IN THIS AREA  
FUNCTIONAL AREA  
8
0
SUPPLY VOLTAGE [V]  
2.5  
3
VIT-3.5V  
4
4.5  
5
5.5  
2)4)  
Figure 54. Low LVD Threshold Versus V and f  
for Flash devices  
DD  
OSC  
FUNCTIONALITY NOT GUARANTEED IN THIS AREA  
FOR TEMPERATURES HIGHER THAN 85°C  
f
[MHz]  
FUNCTIONALITY  
NOT GUARANTEED  
IN THIS AREA  
OSC  
16  
12  
DEVICE UNDER  
RESET  
IN THIS AREA  
FUNCTIONAL AREA  
8
SEE NOTE 4  
0
SUPPLY VOLTAGE [V]  
2.5  
VIT-3V 3.2  
3.5  
4
4.5  
5
5.5  
Notes:  
1. LVD typical data are based on T =25°C. They are given only as design guidelines and are not tested.  
A
2. Data based on characterization results, not tested in production.  
3. The V rise time rate condition is needed to insure a correct device power-on and LVD reset. Not tested in production.  
DD  
4. If the low LVD threshold is selected, when V falls below 3.2V, (V minimum operating voltage), the device is guar-  
DD  
DD  
anteed to continue functioning until it goes into reset state. The specified V min. value is necessary in the device power  
DD  
on phase, but during a power down phase or voltage drop the device will function below this min. level.  
99/135  
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
FUNCTIONAL OPERATING CONDITIONS (Cont’d)  
2)  
Figure 55. High LVD Threshold Versus V and f  
for ROM devices  
DD  
OSC  
f
[MHz]  
FUNCTIONALITY  
NOT GUARANTEED  
IN THIS AREA  
OSC  
16  
DEVICE UNDER  
RESET  
IN THIS AREA  
FUNCTIONAL AREA  
8
0
SUPPLY VOLTAGE [V]  
V
3.85  
IT-  
2.5  
3
3.5  
4
4.5  
5
5.5  
5.5  
5.5  
2)  
Figure 56. Medium LVD Threshold Versus V and f  
for ROM devices  
DD  
OSC  
f
[MHz]  
FUNCTIONALITY  
NOT GUARANTEED  
IN THIS AREA  
OSC  
16  
DEVICE UNDER  
RESET  
IN THIS AREA  
FUNCTIONAL AREA  
8
0
SUPPLY VOLTAGE [V]  
2.5  
3
VIT-3.5V  
4
4.5  
5
2)3)  
Figure 57. Low LVD Threshold Versus V and f  
for ROM devices  
DD  
OSC  
f
[MHz]  
FUNCTIONALITY  
NOT GUARANTEED  
IN THIS AREA  
OSC  
16  
DEVICE UNDER  
RESET  
IN THIS AREA  
FUNCTIONAL AREA  
8
0
SUPPLY VOLTAGE [V]  
2.5  
VIT-3.00V  
3.5  
4
4.5  
5
Notes:  
1. LVD typical data are based on T =25°C. They are given only as design guidelines and are not tested.  
A
2. The minimum V rise time rate is needed to insure a correct device power-on and LVD reset. Not tested in production.  
DD  
3. If the low LVD threshold is selected, when V falls below 3.2V, the device is guaranteed to be either functioning or  
DD  
under reset.  
100/135  
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
13.4 SUPPLY CURRENT CHARACTERISTICS  
The following current consumption specified for  
the ST7 functional operating modes over tempera-  
ture range does not take into account the clock  
source current consumption. To get the total de-  
vice consumption, the two current values must be  
added (except for HALT mode for which the clock  
is stopped).  
Symbol  
Parameter  
Conditions  
Max  
Unit  
Supply current variation vs. temperature  
Constant V and f  
10  
%
I  
DD  
CPU  
DD(Ta)  
13.4.1 RUN and SLOW Modes  
1)  
2)  
Symbol  
Parameter  
Conditions  
Typ  
500  
Max  
Unit  
f
f
f
=1MHz, f  
=4MHz, f  
=500kHz  
=2MHz  
900  
2500  
9000  
3)  
OSC  
OSC  
OSC  
CPU  
Supply current in RUN mode  
(see Figure 58)  
1500  
5600  
CPU  
=16MHz, f  
=8MHz  
CPU  
f
f
f
=1MHz, f  
=4MHz, f  
=16MHz, f  
=31.25kHz  
=125kHz  
150  
250  
670  
450  
550  
1250  
4)  
4)  
OSC  
OSC  
OSC  
CPU  
Supply current in SLOW mode  
(see Figure 59)  
CPU  
=500kHz  
CPU  
I
µA  
DD  
f
f
f
=1MHz, f  
=4MHz, f  
=16MHz, f  
=500kHz  
=2MHz  
300  
970  
3600  
550  
1350  
4500  
3)  
OSC  
OSC  
OSC  
CPU  
Supply current in RUN mode  
(see Figure 58)  
CPU  
=8MHz  
CPU  
f
f
f
=1MHz, f  
=4MHz, f  
=16MHz, f  
=31.25kHz  
=125kHz  
100  
170  
420  
250  
300  
700  
OSC  
OSC  
OSC  
CPU  
Supply current in SLOW mode  
(see Figure 59)  
CPU  
=500kHz  
CPU  
Figure 58. Typical I in RUN vs. f  
Figure 59. Typical I in SLOW vs. f  
CPU  
DD  
CPU  
DD  
IDD [mA]  
IDD [mA]  
7
500kHz  
250kHz  
125kHz  
31.25kHz  
0.8  
0.7  
0.6  
0.5  
0.4  
0.3  
0.2  
0.1  
0
8MHz  
4MHz  
2MHz  
6
5
4
3
2
1
0
500kHz  
3.2  
3.5  
4
4.5  
5
5.5  
3.2  
3.5  
4
4.5  
5
5.5  
VDD [V]  
VDD [V]  
Notes:  
1. Typical data are based on TA=25°C, V =5V (4.5VV 5.5V range) and V =3.4V (3.2VV 3.6V range).  
DD  
DD  
DD  
DD  
2. Data based on characterization results, tested in production at V max. and f  
max.  
DD  
CPU  
3. CPU running with memory access, all I/O pins in input mode with a static value at V or V (no load), all peripherals  
DD  
SS  
in reset state; clock input (OSC1) driven by external square wave, CSS and LVD disabled.  
4. SLOW mode selected with f  
SS  
based on f  
divided by 32. All I/O pins in input mode with a static value at V or  
OSC DD  
CPU  
V
(no load), all peripherals in reset state; clock input (OSC1) driven by external square wave, CSS and LVD disabled.  
101/135  
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
SUPPLY CURRENT CHARACTERISTICS (Cont’d)  
13.4.2 WAIT and SLOW WAIT Modes  
1)  
2)  
Symbol  
Parameter  
Conditions  
Typ  
150  
Max  
Unit  
f
f
f
=1MHz, f  
=500kHz  
=2MHz  
=8MHz  
280  
900  
3000  
3)  
OSC  
OSC  
OSC  
CPU  
Supply current in WAIT mode  
(see Figure 60)  
=4MHz, f  
560  
2200  
CPU  
=16MHz, f  
CPU  
f
f
f
=1MHz, f  
=4MHz, f  
=16MHz, f  
=31.25kHz  
=125kHz  
=500kHz  
20  
90  
340  
70  
190  
850  
4)  
4)  
OSC  
OSC  
OSC  
CPU  
CPU  
Supply current in SLOW WAIT mode  
(see Figure 61)  
CPU  
I
µA  
DD  
f
f
f
=1MHz, f  
=4MHz, f  
=16MHz, f  
=500kHz  
=2MHz  
=8MHz  
90  
350  
1370  
200  
550  
1900  
3)  
OSC  
OSC  
OSC  
CPU  
Supply current in WAIT mode  
CPU  
(see Figure 60)  
CPU  
f
f
f
=1MHz, f  
=4MHz, f  
=16MHz, f  
=31.25kHz  
=125kHz  
=500kHz  
10  
50  
200  
20  
80  
350  
OSC  
OSC  
OSC  
CPU  
Supply current in SLOW WAIT mode  
(see Figure 61)  
CPU  
CPU  
Figure 60. Typical I in WAIT vs. f  
Figure 61. Typical I in SLOW-WAIT vs. f  
DD  
CPU  
DD  
CPU  
IDD [mA]  
IDD [mA]  
8MHz  
4MHz  
2MHz  
500kHz  
500kHz  
250kHz  
125kHz  
3
2.5  
2
0.35  
31.25kHz  
0.3  
0.25  
0.2  
1.5  
1
0.15  
0.1  
0.5  
0
0.05  
0
3.2  
3.5  
4
4.5  
5
5.5  
3.2  
3.5  
4
4.5  
5
5.5  
VDD [V]  
VDD [V]  
Notes:  
1. Typical data are based on T =25°C, V =5V (4.5VV 5.5V range) and V =3.4V (3.2VV 3.6V range).  
A
DD  
DD  
DD  
DD  
2. Data based on characterization results, tested in production at V max. and f  
max.  
DD  
CPU  
3. All I/O pins in input mode with a static value at V or V (no load), all peripherals in reset state; clock input (OSC1)  
DD  
SS  
driven by external square wave, CSS and LVD disabled.  
4. SLOW-WAIT mode selected with f  
DD  
disabled.  
based on f  
divided by 32. All I/O pins in input mode with a static value at  
CPU  
OSC  
V
or V (no load), all peripherals in reset state; clock input (OSC1) driven by external square wave, CSS and LVD  
SS  
102/135  
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
SUPPLY CURRENT CHARACTERISTICS (Cont’d)  
13.4.3 HALT Mode  
Symbol  
1)  
Parameter  
Conditions  
-40°CT +85°C  
Typ  
Max  
10  
Unit  
A
V
V
=5.5V  
=3.6V  
DD  
DD  
-40°CT +125°C  
150  
6
A
2)  
I
Supply current in HALT mode  
-
µA  
DD  
-40°CT +85°C  
A
-40°CT +125°C  
100  
A
13.4.4 Supply and Clock Managers  
The previous current consumption specified for  
the ST7 functional operating modes over tempera-  
ture range does not take into account the clock  
source current consumption. To get the total de-  
vice consumption, the two current values must be  
added (except for HALT mode).  
1)  
3)  
Symbol  
Parameter  
Conditions  
Typ  
Max  
Unit  
Supply current of internal RC oscillator  
Supply current of external RC oscillator  
500  
525  
750  
750  
4)  
LP: Low power oscillator  
200  
300  
450  
700  
400  
550  
750  
I
MP: Medium power oscillator  
MS: Medium speed oscillator  
HS: High speed oscillator  
DD(CK)  
4) & 5)  
Supply current of resonator oscillator  
µA  
1000  
Clock security system supply current  
LVD supply current  
150  
100  
350  
150  
I
HALT mode  
DD(LVD)  
13.4.5 On-Chip Peripherals  
Symbol  
Parameter  
Conditions  
Typ  
50  
Unit  
V
V
V
V
V
V
V
V
=3.4V  
=5.0V  
=3.4V  
=5.0V  
=3.4V  
=5.0V  
=3.4V  
=5.0V  
DD  
DD  
DD  
DD  
DD  
DD  
DD  
DD  
6)  
I
16-bit Timer supply current  
f
f
f
f
=8MHz  
=8MHz  
=8MHz  
=4MHz  
DD(TIM)  
CPU  
CPU  
CPU  
ADC  
150  
250  
350  
250  
350  
800  
1100  
7)  
8)  
I
SPI supply current  
DD(SPI)  
µA  
2
I
I C supply current  
DD(I2C)  
9)  
I
ADC supply current when converting  
DD(ADC)  
Notes:  
1. Typical data are based on T =25°C.  
A
2. All I/O pins in input mode with a static value at V or V (no load), CSS and LVD disabled. Data based on charac-  
DD  
SS  
CPU  
terization results, tested in production at V max. and f  
max.  
DD  
3. Data based on characterization results, not tested in production.  
4. Data based on characterization results done with the external components specified in Section 13.5.3 and Section  
13.5.4, not tested in production.  
5. As the oscillator is based on a current source, the consumption does not depend on the voltage.  
6. Data based on a differential I measurement between reset configuration (timer counter running at f  
/4) and timer  
DD  
CPU  
counter stopped (selecting external clock capability). Data valid for one timer.  
7. Data based on a differential I measurement between reset configuration and a permanent SPI master communica-  
DD  
tion (data sent equal to 55h).  
8. Data based on a differential I measurement between reset configuration and I2C peripheral enabled (PE bit set).  
DD  
9. Data based on a differential I measurement between reset configuration and continuous A/D conversions.  
DD  
103/135  
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
13.5 CLOCK AND TIMING CHARACTERISTICS  
Subject to general operating conditions for V , f  
, and T .  
DD OSC  
A
13.5.1 General Timings  
1)  
Symbol  
Parameter  
Conditions  
Min  
2
Typ  
Max  
12  
Unit  
3
t
CPU  
t
Instruction cycle time  
c(INST)  
f
f
=8MHz  
250  
10  
375  
1500  
22  
ns  
CPU  
CPU  
2)  
t
Interrupt reaction time  
CPU  
t
v(IT)  
t
= t  
+ 10  
c(INST)  
=8MHz  
1.25  
2.75  
µs  
v(IT)  
13.5.2 External Clock Source  
Symbol  
Parameter  
Conditions  
Min  
0.7xV  
Typ  
Max  
Unit  
V
OSC1 input pin high level voltage  
OSC1 input pin low level voltage  
V
DD  
OSC1H  
DD  
SS  
V
V
V
0.3xV  
OSC1L  
DD  
t
t
3)  
w(OSC1H)  
see Figure 62  
OSC1 high or low time  
15  
w(OSC1L)  
ns  
t
t
3)  
r(OSC1)  
OSC1 rise or fall time  
15  
1
f(OSC1)  
I
OSCx Input leakage current  
V
V V  
DD  
µA  
L
SS  
IN  
Figure 62. Typical Application with an External Clock Source  
90%  
V
V
OSC1H  
OSC1L  
10%  
t
t
w(OSC1H)  
t
t
w(OSC1L)  
f(OSC1)  
r(OSC1)  
OSC2  
Not connected internally  
f
OSC  
EXTERNAL  
CLOCK SOURCE  
I
L
OSC1  
ST72XXX  
Notes:  
1. Data based on typical application software.  
2. Time measured between interrupt event and interrupt vector fetch. t  
finish the current instruction execution.  
is the number of t  
cycles needed to  
c(INST)  
CPU  
3. Data based on design simulation and/or technology characteristics, not tested in production.  
104/135  
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
CLOCK AND TIMING CHARACTERISTICS (Cont’d)  
13.5.3 Crystal and Ceramic Resonator Oscillators  
The ST7 internal clock can be supplied with four  
different Crystal/Ceramic resonator oscillators. All  
the information given in this paragraph are based  
on characterization results with specified typical  
external components. In the application, the reso-  
nator and the load capacitors have to be placed as  
close as possible to the oscillator pins in order to  
minimize output distortion and start-up stabiliza-  
tion time. Refer to the crystal/ceramic resonator  
manufacturer for more details (frequency, pack-  
age, accuracy...).  
Symbol  
Parameter  
Conditions  
LP: Low power oscillator  
MP: Medium power oscillator  
MS: Medium speed oscillator  
HS: High speed oscillator  
Min  
1
>2  
>4  
>8  
Max  
2
4
8
16  
Unit  
MHz  
kΩ  
3)  
f
Oscillator Frequency  
OSC  
R
Feedback resistor  
20  
40  
F
R =200LP oscillator  
38  
32  
18  
15  
56  
46  
26  
21  
S
Recommended load capacitance ver-  
sus equivalent serial resistance of the  
C
R =200MP oscillator  
L1  
L2  
S
pF  
R =200MS oscillator  
C
S
crystal or ceramic resonator (R )  
S
R =100HS oscillator  
S
V
=5VLP oscillator  
40  
100  
190  
360  
700  
DD  
V =V MP oscillator  
MS oscillator  
HS oscillator  
110  
180  
400  
IN  
SS  
i
OSC2 driving current  
µA  
2
13.5.3.1 Typical Crystal Resonators  
Option Byte  
Configuration  
C
C
t
1)  
L1  
L2 SU(osc)  
2)  
Reference  
Freq.  
Characteristic  
[pF] [pF] [ms]  
2MHz  
4MHz  
LP  
MP  
MS  
HS  
S-200-30-30/50  
f  
f  
f  
f  
=[ 30ppm  
=[ 30ppm  
=[ 30ppm  
=[ 30ppm  
, 30ppm ], Typ. R =20033 34 10~15  
OSC  
OSC  
OSC  
OSC  
25°C  
25°C  
25°C  
25°C  
Ta  
S
SS3-400-30-30/30  
SS3-800-30-30/30  
SS3-1600-30-30/30  
, 30ppm ], Typ. R =60Ω  
33 34 7~10  
33 34 2.5~3  
33 34 1~1.5  
Ta  
S
8MHz  
, 30ppm ], Typ. R =25Ω  
Ta  
S
16MHz  
, 30ppm ], Typ. R =15Ω  
Ta  
S
Figure 63. Typical Application with a Crystal Resonator  
i
2
f
OSC  
C
L1  
OSC1  
OSC2  
RESONATOR  
R
F
C
L2  
ST72XXX  
Notes:  
1. Resonator characteristics given by the crystal manufacturer.  
2. t is the typical oscillator start-up time measured between V =2.8V and the fetch of the first instruction (with a  
SU(OSC)  
DD  
quick V ramp-up from 0 to 5V (<50µs).  
DD  
3. The oscillator selection can be optimized in terms of supply current using an high quality resonator with small R value.  
S
Refer to crystal manufacturer for more details.  
105/135  
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
CLOCK AND TIMING CHARACTERISTICS (Cont’d)  
13.5.3.2 Typical Ceramic Resonators  
Symbol  
Parameter  
Conditions  
Typ  
4.2  
2.1  
1.1  
0.7  
Unit  
LP  
2MHz  
4MHz  
8MHz  
16MHz  
MP  
MS  
HS  
t
Ceramic resonator start-up time  
ms  
SU(osc)  
t
is the typical oscillator start-up time measured between V =2.8V and the fetch of the first in-  
DD  
SU(OSC)  
struction (with a quick V ramp-up from 0 to 5V (<50µs).  
DD  
Table 21. Typical Ceramic Resonators for Automotive Applications  
f
C
C
R
R
D
Option Byte  
Config.  
OSC  
L1  
3)  
L2  
3)  
FEXT  
1)  
Resonator Part Number  
CSB1000JA  
(MHz)  
[pF]  
[pF]  
[k]  
[k]  
1
100  
(47)  
(15)  
100  
(47)  
(15)  
3.3  
CSBF1000JA  
LP  
MP  
MS  
CSTS0200MGA06  
CSTCC2.00MGA0H6  
CSTS0200MGA06  
CSTCC2.00MGA0H6  
CSTS0400MGA06  
CSTCC4.00MGA0H6  
CSTS0400MGA06  
CSTCC4.00MGA0H6  
CSTS0800MGA06  
CSTCC8.00MGA0H6  
CSTS0800MGA06  
CSTCC8.00MGA0H6  
CSTS1000MGA03  
CSTCC10.0MGA  
2
2
4
4
Open  
8
0
8
10  
12  
CST12.0MTWA  
30  
(30)  
15  
30  
(30)  
15  
HS  
CSTCS12.0MTA  
CSA16.00MXZA040  
CST16.00MXWA0C3  
CSACV16.00MXA040Q  
CSTCV16.00MXA0H3Q  
(15)  
15  
(15)  
15  
2)  
16  
10  
(15)  
(15)  
Notes:  
1. Murata Ceralock (refer to Table 22 for correlation factor)  
2. V 4.5 to 5.5V  
DD  
3. Values in parentheses refer to the capacitors integrated in the resonator  
106/135  
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
CLOCK AND TIMING CHARACTERISTICS (Cont’d)  
Figure 64. Typical Application with Ceramic Resonator  
WHEN RESONATOR WITH  
INTEGRATED CAPACITORS  
i
2
f
OSC  
C
L1  
OSC1  
OSC2  
RESONATOR  
R
R
F(EXT)  
F
C
L2  
ST72XXX  
R
D
Notes:  
1. Resonator characteristics given by the ceramic resonator manufacturer.  
2. t is the typical oscillator start-up time measured between V =2.8V and the fetch of the first instruction (with a  
SU(OSC)  
DD  
quick V ramp-up from 0 to 5V (<50µs).  
DD  
3. The oscillator selection can be optimized in terms of supply current using an high quality resonator with small R value.  
S
Refer to ceramic resonator manufacturer for more details.  
1)  
Table 22. Ceramic Resonator Frequency Correlation Factor  
1)  
Option Byte Configuration  
Resonator  
Correlation %  
+0.03  
-0.16  
Reference IC  
4069UBE  
CSB1000J  
CSTS0200MG06  
CSTCC2.00MG0H6  
CSTS0200MG06  
CSTCC2.00MG0H6  
CSTS0400MG06  
CSTS0400MGA06  
CSTCC4.00MG0H6  
CSTS0200MG06  
CSTCC2.00MG0H6  
CSTS0400MG06  
CSTS0400MGA06  
CSTCC4.00MG0H6  
CSTS0200MG06  
CSTS0800MG06  
CSTS0800MGA06  
CSTCC8.00MG0H6  
CSTS1000MG03  
CSTCC10.0MG  
LP  
-0.10  
-0.15  
74HCU04  
-0.14  
MP  
MS  
0.00  
-0.01  
-0.02  
-0.15  
-0.14  
0.00  
74HCU04  
74HCU04  
-0.01  
-0.02  
-0.15  
+0.10  
+0.07  
+0.09  
+0.34  
+0.75  
+0.45  
+0.30  
+0.50  
+0.10  
+0.09  
+0.03  
+0.09  
4069UBP  
4069UBE  
4069UBE  
40H004  
CST12.0MTW  
HS  
CSTCV12.0MTJ0C4  
CSTCS12.0MTA  
4069UBE  
CSA16.00MXZ040  
CSACV16.00MXJ040  
CSACW1600MX03  
CSACV16.00MXA040Q  
74HCU04  
Notes:  
1. See Table 21 for ceramic resonator values.  
107/135  
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
CLOCK CHARACTERISTICS (Cont’d)  
13.5.4 RC Oscillators  
The ST7 internal clock can be supplied with an RC  
oscillator. This oscillator can be used with internal  
or external components (selectable by option  
byte).  
Symbol  
Parameter  
Internal RC oscillator frequency  
Conditions  
see Figure 66  
Min  
3.60  
1
Typ  
Max  
5.10  
14  
Unit  
1)  
f
MHz  
OSC  
2)  
External RC oscillator frequency  
Internal RC oscillator start-up time  
3)  
2.0  
R
R
R
R
= 47KΩ, C = “0”pF  
1.0  
6.5  
0.7  
3.0  
EX  
EX  
EX  
EX  
EX  
t
ms  
= 47KΩ, C = 100pF  
SU(OSC)  
3)  
EX  
External RC oscillator start-up time  
= 10KΩ, C = 6.8pF  
EX  
= 10KΩ, C = 470pF  
EX  
4)  
R
C
Oscillator external resistor  
10  
47  
KΩ  
pF  
EX  
EX  
see Figure 67  
5)  
Oscillator external capacitor  
0
470  
Figure 65. Typical Application with RC oscillator  
ST72XXX  
V
DD  
INTERNAL RC  
Current copy  
EXTERNAL RC  
+
-
V
f
REF  
OSC  
R
EX  
OSC1  
OSC2  
C
EX  
Voltage generator  
CEX discharge  
Figure 66. Typical Internal RC Oscillator  
Figure 67. Typical External RC Oscillator  
fosc [MHz]  
fosc [MHz]  
Rex=10KOhm  
-40°C  
+25°C  
+85°C  
20  
15  
10  
5
4.3  
4.2  
4.1  
4
Rex=15KOhm  
Rex=22KOhm  
Rex=33KOhm  
Rex=39KOhm  
Rex=47KOhm  
+125°C  
3.9  
3.8  
0
0
6.8  
22  
47  
100  
270  
470  
3.2  
5.5  
Cex [pF]  
VDD [V]  
Notes:  
1. Data based on characterization results.  
2. Guaranteed frequency range with the specified C and R ranges taking into account the device process variation.  
EX  
EX  
Data based on design simulation.  
3. Data based on characterization results done with V nominal at 5V, not tested in production.  
DD  
4. R must have a positive temperature coefficient (ppm/°C), carbon resistors should therefore not be used.  
EX  
5. Important: When no external C is applied, the capacitance to be considered is the global parasitic capacitance  
EX  
which is subject to high variation (package, application...). In this case, the RC oscillator frequency tuning has to be done  
by trying out several resistor values.  
108/135  
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
CLOCK CHARACTERISTICS (Cont’d)  
13.5.5 Clock Security System (CSS)  
Symbol  
Parameter  
Conditions  
T =25°C, V =5.0V  
Min  
250  
190  
Typ  
340  
260  
30  
Max  
550  
450  
Unit  
kHz  
A
DD  
1)  
f
Safe Oscillator Frequency  
SFOSC  
GFOSC  
T =25°C, V =3.4V  
A
DD  
2)  
f
Glitch Filtered Frequency  
MHz  
Figure 68. Typical Safe Oscillator Frequencies  
fosc [kHz]  
400  
-40°C  
+25°C  
+85°C  
+125°C  
350  
300  
250  
200  
3.2  
5.5  
VDD [V]  
Notes:  
1. Data based on characterization results, tested in production between 90 kHz and 600 kHz.  
2. Filtered glitch on the f signal. See functional description in Section 6.5 on page 23 for more details.  
OSC  
109/135  
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
13.6 MEMORY CHARACTERISTICS  
Subject to general operating conditions for V , f  
, and T unless otherwise specified.  
A
DD OSC  
13.6.1 RAM and Hardware Registers  
Symbol  
Parameter  
Conditions  
Min  
Typ  
Max  
Unit  
1)  
V
Data retention mode  
HALT mode (or RESET)  
1.6  
V
RM  
13.6.2 Flash Program Memory  
Symbol  
Parameter  
Programming temperature range  
Programming time for 1~16 bytes  
Conditions  
Min  
0
Typ  
25  
8
Max  
70  
Unit  
°C  
2)  
T
A(prog)  
3)  
T =+25°C  
25  
ms  
A
t
prog  
Programming time for 4 or 8Kbytes T =+25°C  
2.1  
6.4  
sec  
A
5)  
4)  
t
Data retention  
T =+55°C  
20  
years  
cycles  
ret  
A
5)  
N
Write erase cycles  
T =+25°C  
100  
RW  
A
Notes:  
1. Minimum V supply voltage without losing data stored in RAM (in HALT mode or under RESET) or in hardware reg-  
DD  
isters (only in HALT mode). Guaranteed by construction, not tested in production.  
2. Data based on characterization results, tested in production at T =25°C.  
A
3. Up to 16 bytes can be programmed at a time for a 4 Kbyte Flash block (then up to 32 bytes at a time for an 8 Kbyte  
device)  
4. The data retention time increases when the T decreases.  
A
5. Data based on reliability test results and monitored in production.  
110/135  
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
13.7 EMC CHARACTERISTICS  
Susceptibility tests are performed on a sample ba-  
sis during product characterization.  
ESD: Electrostatic Discharge (positive and  
negative) is applied on all pins of the device until  
a functional disturbance occurs. This test  
conforms with the IEC 1000-4-2 standard.  
13.7.1 Functional EMS  
(Electromagnetic Susceptibility)  
FTB: A Burst of Fast Transient voltage (positive  
Based on a simple running application on the  
product (toggling two LEDs through I/O ports), the  
product is stressed by two electromagnetic events  
until a failure occurs (indicated by the LEDs).  
and negative) is applied to V and V through  
DD  
SS  
a 100pF capacitor, until a functional disturbance  
occurs. This test conforms with the IEC 1000-4-  
4 standard.  
A device reset allows normal operations to be re-  
sumed.  
1)  
1)  
Symbol  
Parameter  
Voltage limits to be applied on any I/O pin  
to induce a functional disturbance  
Conditions  
=5V, T =+25°C, f  
conforms to IEC 1000-4-2  
Neg  
Pos  
Unit  
V
=8MHz  
OSC  
DD  
A
V
-1  
1
FESD  
kV  
Fast transient voltage burst limits to be ap-  
V
=5V, T =+25°C, f  
=8MHz  
OSC  
DD  
A
V
plied through 100pF on V and V pins  
-4  
4
FFTB  
DD  
DD  
conforms to IEC 1000-4-4  
to induce a functional disturbance  
2)  
Figure 69. EMC Recommended star network power supply connection  
ST72XXX  
10µF 0.1µF  
V
DD  
SS  
ST7  
DIGITAL NOISE  
FILTERING  
V
V
DD  
POWER  
SUPPLY  
SOURCE  
V
V
SSA  
EXTERNAL  
NOISE  
FILTERING  
DDA  
0.1µF  
Notes:  
1. Data based on characterization results, not tested in production.  
2. The suggested 10µF and 0.1µF decoupling capacitors on the power supply lines are proposed as a good price vs. EMC  
performance tradeoff. They have to be put as close as possible to the device power supply pins. Other EMC recommen-  
dations are given in other sections (I/Os, RESET, OSCx pin characteristics).  
111/135  
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
EMC CHARACTERISTICS (Cont’d)  
13.7.2 Absolute Electrical Sensitivity  
Machine Model Test Sequence  
Based on three different tests (ESD, LU and DLU)  
using specific measurement methods, the product  
is stressed in order to determine its performance in  
terms of electrical sensitivity. For more details, re-  
fer to the AN1181 ST7 application note.  
– C is loaded through S1 by the HV pulse gener-  
L
ator.  
– S1 switches position from generator to ST7.  
– A discharge from C to the ST7 occurs.  
L
– S2 must be closed 10 to 100ms after the pulse  
delivery period to ensure the ST7 is not left in  
charge state. S2 must be opened at least 10ms  
prior to the delivery of the next pulse.  
13.7.2.1 Electrostatic Discharge (ESD)  
Electrostatic Discharges (3 positive then 3 nega-  
tive pulses separated by 1 second) are applied to  
the pins of each sample according to each pin  
combination. The sample size depends of the  
number of supply pins of the device (3 parts*(n+1)  
supply pin). Two models are usually simulated:  
Human Body Model and Machine Model. This test  
conforms to the JESD22-A114A/A115A standard.  
See Figure 70 and the following test sequences.  
– R (machine resistance), in series with S2, en-  
sures a slow discharge of the ST7.  
Human Body Model Test Sequence  
– C is loaded through S1 by the HV pulse gener-  
L
ator.  
– S1 switches position from generator to R.  
– A discharge from C through R (body resistance)  
L
to the ST7 occurs.  
– S2 must be closed 10 to 100ms after the pulse  
delivery period to ensure the ST7 is not left in  
charge state. S2 must be opened at least 10ms  
prior to the delivery of the next pulse.  
Absolute Maximum Ratings  
1)  
Symbol  
Ratings  
Conditions  
Maximum value  
Unit  
Electrostatic discharge voltage  
(Human Body Model)  
V
V
T =+25°C  
2000  
ESD(HBM)  
A
V
Electrostatic discharge voltage  
(Machine Model)  
T =+25°C  
200  
ESD(MM)  
A
Figure 70. Typical Equivalent ESD Circuits  
S1  
R=1500Ω  
S1  
HIGH VOLTAGE  
PULSE  
GENERATOR  
HIGH VOLTAGE  
PULSE  
GENERATOR  
ST7  
ST7  
C =100pF  
S2  
L
S2  
C =200pF  
L
HUMAN BODY MODEL  
MACHINE MODEL  
Notes:  
1. Data based on characterization results, not tested in production.  
112/135  
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
EMC CHARACTERISTICS (Cont’d)  
13.7.2.2 Static and Dynamic Latch-Up  
DLU: Electrostatic Discharges (one positive  
then one negative test) are applied to each pin  
of three samples when the micro is running to  
assess the latch-up performance in dynamic  
mode. Power supplies are set to the typical  
values, the oscillator is connected as near as  
possible to the pins of the micro and the  
component is put in reset mode. This test  
conforms to the IEC1000-4-2 and SAEJ1752/3  
standards and is described in Figure 71. For  
more details, refer to the AN1181 ST7  
application note.  
LU: 3 complementary static tests are required  
on 10 parts to assess the latch-up performance.  
A supply overvoltage (applied to each power  
supply pin), a current injection (applied to each  
input, output and configurable I/O pin) and a  
power supply switch sequence are performed  
on each sample. This test conforms to the EIA/  
JESD 78 IC latch-up standard. For more details,  
refer to the AN1181 ST7 application note.  
Electrical Sensitivities  
1)  
Symbol  
LU  
Parameter  
Static latch-up class  
Conditions  
Class  
T =+25°C  
A
A
A
T =+85°C  
A
DLU  
Dynamic latch-up class  
V
=5.5V, f  
=4MHz, T =+25°C  
A
DD  
OSC  
A
Figure 71. Simplified Diagram of the ESD Generator for DLU  
R
=50MΩ  
R =330Ω  
D
CH  
DISCHARGE TIP  
V
V
DD  
SS  
HV RELAY  
C =150pF  
S
ST7  
ESD  
GENERATOR  
2)  
DISCHARGE  
RETURN CONNECTION  
Notes:  
1. Class description: A Class is an STMicroelectronics internal specification. All its limits are higher than the JEDEC spec-  
ifications, that means when a device belongs to Class A it exceeds the JEDEC standard. B Class strictly covers all the  
JEDEC criteria (international standard).  
2. Schaffner NSG435 with a pointed test finger.  
113/135  
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
EMC CHARACTERISTICS (Cont’d)  
13.7.3 ESD Pin Protection Strategy  
Standard Pin Protection  
To protect an integrated circuit against Electrostat-  
ic Discharge the stress must be controlled to pre-  
vent degradation or destruction of the circuit ele-  
ments. The stress generally affects the circuit ele-  
ments which are connected to the pads but can  
also affect the internal devices when the supply  
pads receive the stress. The elements to be pro-  
tected must not receive excessive current, voltage  
or heating within their structure.  
To protect the output structure the following ele-  
ments are added:  
– A diode to V (3a) and a diode from V (3b)  
DD  
SS  
– A protection device between V and V (4)  
DD  
SS  
To protect the input structure the following ele-  
ments are added:  
– A resistor in series with the pad (1)  
– A diode to V (2a) and a diode from V (2b)  
DD  
SS  
– A protection device between V and V (4)  
An ESD network combines the different input and  
output ESD protections. This network works, by al-  
lowing safe discharge paths for the pins subjected  
to ESD stress. Two critical ESD stress cases are  
presented in Figure 72 and Figure 73 for standard  
pins and in Figure 74 and Figure 75 for true open  
drain pins.  
DD  
SS  
Figure 72. Positive Stress on a Standard Pad vs. V  
SS  
V
V
DD  
DD  
(3a)  
(3b)  
(2a)  
(1)  
(4)  
OUT  
IN  
Main path  
(2b)  
Path to avoid  
V
V
V
SS  
SS  
DD  
Figure 73. Negative Stress on a Standard Pad vs. V  
DD  
V
DD  
(3a)  
(3b)  
(2a)  
(1)  
(4)  
OUT  
IN  
Main path  
(2b)  
V
V
SS  
SS  
114/135  
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
EMC CHARACTERISTICS (Cont’d)  
True Open Drain Pin Protection  
Multisupply Configuration  
When several types of ground (V , V  
The centralized protection (4) is not involved in the  
discharge of the ESD stresses applied to true  
open drain pads due to the fact that a P-Buffer and  
, ...) and  
SSA  
SS  
power supply (V , V  
, ...) are available for any  
DD  
DDA  
reason (better noise immunity...), the structure  
shown in Figure 76 is implemented to protect the  
device against ESD.  
diode to V  
are not implemented. An additional  
DD  
local protection between the pad and V (5a &  
SS  
5b) is implemented to completely absorb the posi-  
tive ESD discharge.  
Figure 74. Positive Stress on a True Open Drain Pad vs. V  
SS  
V
V
DD  
DD  
Main path  
(1)  
Path to avoid  
OUT  
(4)  
IN  
(5a)  
(5b)  
(3b)  
(2b)  
V
V
SS  
SS  
Figure 75. Negative Stress on a True Open Drain Pad vs. V  
DD  
V
V
DD  
DD  
Main path  
(1)  
OUT  
(4)  
IN  
(3b)  
(3b)  
(3b)  
(2b)  
V
V
SS  
SS  
Figure 76. Multisupply Configuration  
V
DD  
V
DDA  
V
DDA  
V
SS  
BACK TO BACK DIODE  
BETWEEN GROUNDS  
V
SSA  
V
SSA  
115/135  
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
13.8 I/O PORT PIN CHARACTERISTICS  
13.8.1 General Characteristics  
Subject to general operating conditions for V , f  
, and T unless otherwise specified.  
DD OSC  
A
1)  
Symbol  
Parameter  
Conditions  
Min  
Typ  
Max  
Unit  
V
2)  
V
Input low level voltage  
0.3xV  
IL  
DD  
2)  
V
Input high level voltage  
0.7xV  
IH  
DD  
3)  
V
Schmitt trigger voltage hysteresis  
Input leakage current  
400  
mV  
µA  
hys  
I
V
V V  
SS IN DD  
1
L
4)  
I
Static current consumption  
Floating input mode  
200  
250  
300  
S
V
V
=5V  
62  
120  
200  
5
DD  
DD  
5)  
R
Weak pull-up equivalent resistor  
V
=V  
SS  
kΩ  
pF  
ns  
PU  
IN  
=3.4V  
170  
1
C
I/O pin capacitance  
IO  
6)  
t
Output high to low level fall time  
25  
C =50pF  
Between 10% and 90%  
f(IO)out  
r(IO)out  
L
6)  
t
Output low to high level rise time  
25  
7)  
t
External interrupt pulse time  
t
CPU  
w(IT)in  
Figure 77. Two typical Applications with unused I/O Pin  
V
ST72XXX  
DD  
UNUSED I/O PORT  
10kΩ  
10kΩ  
UNUSED I/O PORT  
ST72XXX  
Figure 78. Typical I vs. V with V =V  
SS  
PU  
DD  
IN  
Ipu [µA]  
70  
Ta=-40°C  
Ta=25°C  
Ta=85°C  
60  
Ta=125°C  
50  
40  
30  
20  
10  
0
3.2  
3.5  
4
4.5  
5
5.5  
Vdd [V]  
Notes:  
1. Unless otherwise specified, typical data are based on T =25°C and V =5V.  
A
DD  
2. Data based on characterization results, not tested in production.  
3. Hysteresis voltage between Schmitt trigger switching levels. Based on characterization results, not tested.  
4. Configuration not recommended, all unused pins must be kept at a fixed voltage: using the output mode of the I/O for  
example or an external pull-up or pull-down resistor (see Figure 77). Data based on design simulation and/or technology  
characteristics, not tested in production.  
5. The R pull-up equivalent resistor is based on a resistive transistor (corresponding I current characteristics de-  
PU  
PU  
scribed in Figure 78). This data is based on characterization results, tested in production at V max.  
DD  
6. Data based on characterization results, not tested in production.  
7. To generate an external interrupt, a minimum pulse width has to be applied on an I/O port pin configured as an external  
interrupt source.  
116/135  
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
I/O PORT PIN CHARACTERISTICS (Cont’d)  
13.8.2 Output Driving Current  
Subject to general operating conditions for V , f  
, and T unless otherwise specified.  
DD OSC  
A
Symbol  
Parameter  
Conditions  
I =+5mA T 85°C  
Min  
Max  
Unit  
1.3  
1.5  
IO  
A
Output low level voltage for a standard I/O pin  
when 8 pins are sunk at same time  
(see Figure 79 and Figure 82)  
T 85°C  
A
0.65  
0.75  
I =+2mA T 85°C  
IO  
A
T 85°C  
A
1)  
V
OL  
I =+20mA,T 85°C  
1.5  
1.7  
IO  
A
Output low level voltage for a high sink I/O pin  
when 4 pins are sunk at same time  
(see Figure 80 and Figure 83)  
T 85°C  
A
V
0.75  
0.85  
I =+8mA T 85°C  
IO  
A
T 85°C  
A
I =-5mA, T 85°C  
V
V
-1.6  
-1.7  
IO  
A
DD  
DD  
Output high level voltage for an I/O pin  
when 4 pins are sourced at same time  
(see Figure 81 and Figure 84)  
T 85°C  
A
2)  
V
OH  
I =-2mA T 85°C  
V
V
-0.8  
-1.0  
IO  
A
DD  
DD  
T 85°C  
A
Figure 79. Typical V at V =5V (standard)  
Figure 81. Typical V at V =5V  
OH DD  
OL  
DD  
Vol [V] at Vdd=5V  
Voh [V] at Vdd=5V  
6
2.5  
Ta=-40°C  
2
Ta=85°C  
5
4
3
2
1
Ta=25°C  
1.5  
Ta=125°C  
Ta=-40°C Ta=85°C  
Ta=25°C Ta=125°C  
1
0.5  
0
0
2
4
6
8
10  
-8  
-6  
-4  
Iio [mA]  
-2  
0
Iio [mA]  
Figure 80. Typical V at V =5V (high-sink)  
OL  
DD  
Vol [V] at Vdd=5V  
2
Ta=-40°C  
Ta=85°C  
1.5  
Ta=25°C  
Ta=125°C  
1
0.5  
0
0
5
10  
15  
Iio [mA]  
20  
25  
30  
Notes:  
1. The I current sunk must always respect the absolute maximum rating specified in Section 13.2.2 and the sum of I  
IO  
IO  
(I/O ports and control pins) must not exceed I  
.
VSS  
2. The I current sourced must always respect the absolute maximum rating specified in Section 13.2.2 and the sum of  
IO  
I
(I/O ports and control pins) must not exceed I  
. True open drain I/O pins does not have V  
.
IO  
VDD  
OH  
117/135  
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
I/O PORT PIN CHARACTERISTICS (Cont’d)  
Figure 82. Typical V vs. V (standard I/Os)  
OL  
DD  
Ta=-40°C Ta=85°C  
Ta=25°C Ta=125°C  
Ta=-40°C Ta=85°C  
Ta=25°C Ta=125°C  
Vol [V] at Iio=2mA  
0.5  
Vol [V] at Iio=5mA  
1.4  
1.3  
1.2  
1.1  
1
0.9  
0.8  
0.7  
0.6  
0.5  
0.45  
0.4  
0.35  
0.3  
0.25  
0.2  
3.2  
3.5  
4
4.5  
5
5.5  
3.2  
3.5  
4
4.5  
Vdd [V]  
5
5.5  
Vdd [V]  
Figure 83. Typical V vs. V (high-sink I/Os)  
OL  
DD  
Ta=-40°C Ta=85°C  
Ta=-40°C Ta=85°C  
Ta=25°C Ta=125°C  
Vol [V] at Iio=8mA  
Vol [V] at Iio=20mA  
1.5  
0.55  
0.5  
Ta=25°C  
Ta=125°C  
1.3  
1.1  
0.9  
0.7  
0.5  
0.45  
0.4  
0.35  
0.3  
0.25  
0.2  
3.2  
3.5  
4
4.5  
5
5.5  
3.2  
3.5  
4
4.5  
5
5.5  
Vdd [V]  
Vdd [V]  
Figure 84. Typical V vs. V  
OH  
DD  
Voh [V] at Iio=-2mA  
Voh [V] at Iio=-5mA  
5
5.5  
5
4
3
2
1
0
4.5  
4
Ta=-40°C Ta=85°C  
3.5  
3
Ta=-40°C Ta=85°C  
Ta=25°C  
5
Ta=125°C  
5.5  
Ta=25°C  
Ta=125°C  
5.5  
2.5  
2
3.2  
3.5  
4
4.5  
5
3.5  
4
4.5  
Vdd [V]  
Vdd [V]  
118/135  
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
13.9 CONTROL PIN CHARACTERISTICS  
13.9.1 Asynchronous RESET Pin  
Subject to general operating conditions for V , f  
, and T unless otherwise specified.  
DD OSC  
A
1)  
Symbol  
Parameter  
Conditions  
Min  
Typ  
Max  
0.3xV  
Unit  
V
2)  
V
Input low level voltage  
IL  
DD  
2)  
V
Input high level voltage  
0.7xV  
IH  
DD  
3)  
V
Schmitt trigger voltage hysteresis  
400  
0.68  
0.28  
40  
mV  
V
hys  
4)  
I =+5mA  
0.95  
0.45  
60  
Output low level voltage  
IO  
V
V
V
=5V  
OL  
DD  
IN  
(see Figure 87, Figure 88)  
I =+2mA  
IO  
V
V
=5V  
20  
80  
DD  
DD  
5)  
R
Weak pull-up equivalent resistor  
=V  
kΩ  
ON  
SS  
=3.4V  
100  
120  
External pin or  
internal reset sources  
6
30  
1/f  
SFOSC  
t
Generated reset pulse duration  
w(RSTL)out  
µs  
6)  
t
t
External reset pulse hold time  
20  
µs  
ns  
h(RSTL)in  
7)  
Filtered glitch duration  
100  
g(RSTL)in  
8)  
Figure 85. Typical Application with RESET pin  
ST72XXX  
V
DD  
V
V
DD  
DD  
INTERNAL  
RESET CONTROL  
R
ON  
0.1µF  
0.1µF  
4.7kΩ  
USER  
EXTERNAL  
RESET  
RESET  
8)  
CIRCUIT  
WATCHDOG RESET  
LVD RESET  
Notes:  
1. Unless otherwise specified, typical data are based on T =25°C and V =5V.  
A
DD  
2. Data based on characterization results, not tested in production.  
3. Hysteresis voltage between Schmitt trigger switching levels. Based on characterization results, not tested.  
4. The I current sunk must always respect the absolute maximum rating specified in Section 13.2.2 and the sum of I  
IO  
IO  
(I/O ports and control pins) must not exceed I  
.
VSS  
5. The R  
pull-up equivalent resistor is based on a resistive transistor (corresponding I current characteristics de-  
ON  
ON  
scribed in Figure 86). This data is based on characterization results, not tested in production.  
6. To guarantee the reset of the device, a minimum pulse has to be applied to RESET pin. All short pulses applied on  
RESET pin with a duration below t  
can be ignored.  
h(RSTL)in  
7. The reset network (the resistor and two capacitors) protects the device against parasitic resets, especially in a noisy  
environments.  
8. The output of the external reset circuit must have an open-drain output to drive the ST7 reset pad. Otherwise the device  
can be damaged when the ST7 generates an internal reset (LVD or watchdog).  
119/135  
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
CONTROL PIN CHARACTERISTICS (Cont’d)  
Figure 86. Typical I vs. V with V =V  
Figure 87. Typical V at V =5V (RESET)  
OL DD  
ON  
DD  
IN  
SS  
Ion [µA]  
200  
Vol [V] at Vdd=5V  
2
Ta=-40°C  
Ta=25°C  
Ta=85°C  
Ta=125°C  
Ta=-40°C  
Ta=25°C  
Ta=85°C  
Ta=125°C  
150  
100  
50  
1.5  
1
0.5  
0
0
0
1
2
3
4
5
6
7
8
3.2  
3.5  
4
4.5  
5
5.5  
Iio [mA]  
Vdd [V]  
Figure 88. Typical V vs. V (RESET)  
OL  
DD  
Ta=-40°C Ta=85°C  
Ta=25°C Ta=125°C  
Vol [V] at Iio=2mA  
0.5  
Vol [V] at Iio=5mA  
Ta=-40°C Ta=85°C  
Ta=25°C Ta=125°C  
1.2  
1
0.45  
0.4  
0.35  
0.3  
0.8  
0.6  
0.4  
0.25  
0.2  
3.2  
3.5  
4
4.5  
5
5.5  
3.2  
3.5  
4
4.5  
5
5.5  
Vdd [V]  
Vdd [V]  
120/135  
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
CONTROL PIN CHARACTERISTICS (Cont’d)  
13.9.2 ISPSEL Pin  
Subject to general operating conditions for V , f  
, and T unless otherwise specified.  
DD OSC  
A
Symbol  
Parameter  
Conditions  
Min  
Max  
Unit  
V
1)  
V
Input low level voltage  
V
0.2  
IL  
IH  
L
SS  
1)  
V
I
Input high level voltage  
Input leakage current  
V
-0.1 12.6  
1
DD  
V =V  
µA  
IN  
SS  
2)  
Figure 89. Two typical Applications with ISPSEL Pin  
ISPSEL  
ISPSEL  
PROGRAMMING  
TOOL  
10kΩ  
ST72XXX  
ST72XXX  
Notes:  
1. Data based on design simulation and/or technology characteristics, not tested in production.  
2. When the ISP Remote mode is not required by the application ISPSEL pin must be tied to V  
.
SS  
121/135  
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
13.10 TIMER PERIPHERAL CHARACTERISTICS  
Subject to general operating conditions for V  
,
Refer to I/O port characteristics for more details on  
the input/output alternate function characteristics  
(output compare, input capture, external clock,  
PWM output...).  
DD  
f
, and T unless otherwise specified.  
OSC  
A
13.10.1 Watchdog Timer  
Symbol  
Parameter  
Conditions  
Min  
12,288  
1.54  
Typ  
Max  
786,432  
98.3  
Unit  
t
CPU  
t
Watchdog time-out duration  
w(WDG)  
f
=8MHz  
ms  
CPU  
13.10.2 16-Bit Timer  
Symbol  
Parameter  
Conditions  
Min  
1
Typ  
Max  
Unit  
t
Input capture pulse time  
t
t
w(ICAP)in  
CPU  
2
CPU  
t
PWM resolution time  
res(PWM)  
f
=8MHz  
250  
0
ns  
CPU  
f
Timer external clock frequency  
PWM repetition rate  
f
f
/4  
/4  
MHz  
MHz  
bit  
EXT  
CPU  
f
0
PWM  
CPU  
Res  
PWM resolution  
16  
PWM  
122/135  
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
13.11 COMMUNICATION INTERFACE CHARACTERISTICS  
13.11.1 SPI - Serial Peripheral Interface  
Refer to I/O port characteristics for more details on  
the input/output alternate function characteristics  
(SS, SCK, MOSI, MISO).  
Subject to general operating conditions for V  
,
DD  
f
, and T unless otherwise specified.  
OSC  
A
Symbol  
Parameter  
Conditions  
Min  
/128  
0.0625  
Max  
Unit  
Master  
f
f
f
/4  
CPU  
CPU  
f
=8MHz  
2
f
CPU  
SCK  
SPI clock frequency  
MHz  
1/t  
Slave  
=8MHz  
/2  
c(SCK)  
CPU  
0
f
4
CPU  
t
r(SCK)  
SPI clock rise and fall time  
see I/O port pin description  
t
f(SCK)  
su(SS)  
t
SS setup time  
SS hold time  
Slave  
Slave  
120  
120  
t
h(SS)  
t
t
Master  
Slave  
100  
90  
w(SCKH)  
SCK high and low time  
Data input setup time  
Data input hold time  
w(SCKL)  
t
Master  
Slave  
100  
100  
su(MI)  
t
su(SI)  
ns  
t
Master  
Slave  
100  
100  
h(MI)  
t
h(SI)  
t
Data output access time  
Data output disable time  
Data output valid time  
Data output hold time  
Data output valid time  
Data output hold time  
Slave  
Slave  
0
120  
240  
120  
a(SO)  
t
dis(SO)  
t
v(SO)  
h(SO)  
v(MO)  
h(MO)  
Slave (after enable edge)  
t
0
t
0.25  
0.25  
Master (before capture edge)  
t
CPU  
t
Figure 90. SPI Slave Timing Diagram with CPHA=0 3)  
SS  
INPUT  
t
t
su(SS)  
c(SCK)  
t
h(SS)  
CPHA=0  
CPOL=0  
CPHA=0  
CPOL=1  
t
t
w(SCKH)  
w(SCKL)  
t
t
t
t
dis(SO)  
a(SO)  
v(SO)  
h(SO)  
t
t
r(SCK)  
f(SCK)  
see  
note 2  
MISO  
OUTPUT  
INPUT  
MSB OUT  
see note 2  
BIT6 OUT  
LSB OUT  
t
t
h(SI)  
su(SI)  
LSB IN  
MSB IN  
BIT1 IN  
MOSI  
Notes:  
1. Data based on design simulation and/or characterization results, not tested in production.  
2. When no communication is on-going the data output line of the SPI (MOSI in master mode, MISO in slave mode) has  
its alternate function capability released. In this case, the pin status depends on the I/O port configuration.  
3. Measurement points are done at CMOS levels: 0.3xV and 0.7xV  
.
DD  
DD  
123/135  
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
COMMUNICATION INTERFACE CHARACTERISTICS (Cont’d)  
Figure 91. SPI Slave Timing Diagram with CPHA=1 1)  
SS  
INPUT  
t
t
su(SS)  
c(SCK)  
t
h(SS)  
CPHA=1  
CPOL=0  
CPHA=1  
CPOL=1  
t
t
w(SCKH)  
w(SCKL)  
t
t
dis(SO)  
a(SO)  
t
t
h(SO)  
v(SO)  
t
t
r(SCK)  
f(SCK)  
see  
note 2  
see  
note 2  
MISO  
OUTPUT  
MSB OUT  
BIT6 OUT  
HZ  
LSB OUT  
t
t
h(SI)  
su(SI)  
LSB IN  
MSB IN  
BIT1 IN  
MOSI  
INPUT  
Figure 92. SPI Master Timing Diagram 1)  
SS  
INPUT  
t
c(SCK)  
CPHA=0  
CPOL=0  
CPHA=0  
CPOL=1  
CPHA=1  
CPOL=0  
CPHA=1  
CPOL=1  
t
t
w(SCKH)  
w(SCKL)  
t
t
r(SCK)  
f(SCK)  
t
t
h(MI)  
su(MI)  
MISO  
MOSI  
INPUT  
MSB IN  
h(MO)  
BIT6 IN  
LSB IN  
t
t
v(MO)  
MSB OUT  
LSB OUT  
see note 2  
BIT6 OUT  
see note 2  
OUTPUT  
Notes:  
1. Measurement points are done at CMOS levels: 0.3xV and 0.7xV  
.
DD  
DD  
2. When no communication is on-going the data output line of the SPI (MOSI in master mode, MISO in slave mode) has  
its alternate function capability released. In this case, the pin status depends of the I/O port configuration.  
124/135  
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
COMMUNICATION INTERFACE CHARACTERISTICS (Cont’d)  
2
13.11.2 I C - Inter IC Control Interface  
Refer to I/O port characteristics for more details on  
the input/output alternate function characteristics  
Subject to general operating conditions for V  
,
DD  
2
(SDAI and SCLI). The ST7 I C interface meets the  
f
, and T unless otherwise specified.  
OSC  
A
2
requirements of the Standard I C communication  
protocol described in the following table.  
2
2
Standard mode I C  
Fast mode I C  
Symbol  
Parameter  
Unit  
1)  
1)  
1)  
1)  
Min  
Max  
Min  
Max  
t
SCL clock low time  
SCL clock high time  
SDA setup time  
4.7  
4.0  
250  
1.3  
0.6  
w(SCLL)  
µs  
t
w(SCLH)  
t
100  
su(SDA)  
3)  
2)  
3)  
t
SDA data hold time  
0
0
900  
h(SDA)  
t
t
r(SDA)  
ns  
SDA and SCL rise time  
SDA and SCL fall time  
1000  
300  
20+0.1C  
20+0.1C  
300  
300  
b
b
r(SCL)  
t
t
f(SDA)  
f(SCL)  
t
START condition hold time  
4.0  
4.7  
4.0  
4.7  
0.6  
0.6  
0.6  
1.3  
h(STA)  
µs  
t
Repeated START condition setup time  
STOP condition setup time  
su(STA)  
su(STO)  
t
ns  
ms  
pF  
t
STOP to START condition time (bus free)  
Capacitive load for each bus line  
w(STO:STA)  
C
400  
400  
b
2
Figure 93. Typical Application with I C Bus and Timing Diagram 4)  
V
V
DD  
DD  
4.7kΩ  
4.7kΩ  
100Ω  
100Ω  
SDAI  
SCLI  
2
I C BUS  
ST72XXX  
REPEATED START  
START  
t
t
su(STA)  
w(STO:STA)  
START  
SDA  
t
t
r(SDA)  
f(SDA)  
STOP  
t
t
h(SDA)  
su(SDA)  
SCK  
t
t
t
t
t
t
h(STA)  
w(SCKH)  
w(SCKL)  
r(SCK)  
su(STO)  
f(SCK)  
Notes:  
2
1. Data based on standard I C protocol requirement, not tested in production.  
2. The device must internally provide a hold time of at least 300ns for the SDA signal in order to bridge the undefined  
region of the falling edge of SCL.  
3. The maximum hold time of the START condition has only to be met if the interface does not stretch the low period of  
SCL signal.  
4. Measurement points are done at CMOS levels: 0.3xV and 0.7xV  
.
DD  
DD  
125/135  
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
13.12 8-BIT ADC CHARACTERISTICS  
Subject to general operating conditions for V , f  
, and T unless otherwise specified.  
DD OSC  
A
1)  
Symbol  
Parameter  
ADC clock frequency  
Conversion range voltage  
External input resistor  
Conditions  
Min  
Typ  
Max  
Unit  
MHz  
V
f
4
ADC  
2)  
V
R
V
V
AIN  
AIN  
SSA  
DDA  
3)  
10  
kΩ  
C
Internal sample and hold capacitor  
Stabilization time after ADC enable  
Conversion time (Sample+Hold)  
6
pF  
ADC  
STAB  
4)  
t
0
µs  
3
f
=8MHz, f  
=4MHz  
CPU  
ADC  
t
- Sample capacitor loading time  
- Hold conversion time  
4
8
ADC  
1/f  
ADC  
Figure 94. Typical Application with ADC  
V
DD  
V
T
0.6V  
R
AIN  
AINx  
V
AIN  
ADC  
V
0.6V  
T
C
~2pF  
I
L
1µA  
IO  
V
DD  
V
V
DDA  
0.1µF  
SSA  
ST72XXX  
Notes:  
1. Unless otherwise specified, typical data are based on T =25°C and V -V =5V. They are given only as design guide-  
A
DD SS  
lines and are not tested.  
2. When V and V  
pins are not available on the pinout, the ADC refer to V and V .  
SS  
DDA  
SSA  
DD  
3. Any added external serial resistor will downgrade the ADC accuracy (especially for resistance greater than 10k). Data  
based on characterization results, not tested in production.  
4. The stabilization time of the AD converter is masked by the first t  
always valid.  
. The first conversion after the enable is then  
LOAD  
126/135  
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
8-BIT ADC CHARACTERISTICS (Cont’d)  
ADC Accuracy  
Symbol  
2)  
3)  
3)  
V
f
=5V,  
V
f
=5.0V,  
V
f
=3.3V,  
DD  
DD  
DD  
=1MHz  
=8MHz  
=8MHz  
Parameter  
Unit  
CPU  
CPU  
CPU  
Min  
Max  
Min  
Max  
2.0  
1.5  
1.5  
1.5  
1.5  
Min  
Max  
1)  
Total unadjusted error  
2.0  
1.5  
1.5  
1.5  
1.5  
2.0  
1.5  
1.5  
1.5  
1.5  
|E |  
T
1)  
Offset error  
E
E
O
G
1)  
Gain Error  
LSB  
1)  
Differential linearity error  
|E |  
D
1)  
Integral linearity error  
|E |  
L
Figure 95. ADC Accuracy Characteristics  
Digital Result ADCDR  
E
G
(1) Example of an actual transfer curve  
(2) The ideal transfer curve  
(3) End point correlation line  
255  
V
V  
254  
253  
DDA  
SSA  
1LSB  
= ----------------------------------------  
IDEAL  
256  
(2)  
E =Total Unadjusted Error: maximum deviation  
T
E
between the actual and the ideal transfer curves.  
T
(3)  
7
6
5
4
3
2
1
E =Offset Error: deviation between the first actual  
O
transition and the first ideal one.  
(1)  
E =Gain Error: deviation between the last ideal  
G
transition and the last actual one.  
E
E
O
L
E =Differential Linearity Error: maximum deviation  
D
between actual steps and the ideal one.  
E =Integral Linearity Error: maximum deviation  
L
E
between any actual transition and the end point  
correlation line.  
D
1 LSB  
IDEAL  
V
(LSB  
)
IDEAL  
in  
0
1
2
3
4
5
6
7
253 254 255 256  
V
V
DDA  
SSA  
Notes:  
1. ADC Accuracy vs. Negative Injection Current:  
For I =0.8mA, the typical leakage induced inside the die is 1.6µA and the effect on the ADC accuracy is a loss of 1 LSB  
INJ-  
for each 10Kincrease of the external analog source impedance. This effect on the ADC accuracy has been observed  
under worst-case conditions for injection:  
- negative injection  
- injection to an Input with analog capability, adjacent to the enabled Analog Input  
- at 5V V supply, and worst case temperature.  
DD  
2. Data based on characterization results with T =25°C.  
A
3. Data based on characterization results over the whole temperature range.  
127/135  
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
14 PACKAGE CHARACTERISTICS  
14.1 PACKAGE MECHANICAL DATA  
Figure 96. 28-Pin Plastic Small Outline Package, 300-mil Width  
mm  
Dim.  
inches  
Typ  
Min Typ Max Min  
Max  
A
2.35  
2.65 0.0926  
0.30 0.0040  
0.51 0.013  
0.32 0.0091  
18.10 0.6969  
7.60 0.2914  
0.1043  
0.0118  
0.020  
A1 0.10  
B
C
D
E
e
0.33  
0.23  
0.0125  
0.7125  
0.2992  
17.70  
7.40  
1.27  
0.0500  
H
h
10.01  
0.25  
10.64 0.394  
0.74 0.010  
0°  
0.419  
0.029  
8°  
K
L
0.41  
1.27 0.016  
0.10  
0.050  
0.004  
G
SO28  
Number of Pins  
N
28  
®
14.2 ECOPACK  
In accordance with the RoHS European directive,  
all STMicroelectronics packages have been con-  
verted to lead-free technology, named ECO-  
– Detailed information on the STMicroelectron-  
®
ics ECOPACK transition program is availa-  
ble on www.st.com/stonline/leadfree/, with  
specific technical application notes covering  
the main technical aspects related to lead-free  
conversion (AN2033, AN2034, AN2035 and  
AN2036).  
®
PACK .  
®
– ECOPACK packages are qualified according  
to the JEDEC STD-020B compliant soldering  
profile.  
14.3 THERMAL CHARACTERISTICS  
Symbol  
Ratings  
Value  
75  
Unit  
°C/W  
mW  
°C  
R
Package thermal resistance (junction to ambient) SO28  
thJA  
1)  
P
Power dissipation  
500  
150  
D
2)  
T
Maximum junction temperature  
Jmax  
Notes:  
1. The power dissipation is obtained from the formula P =P +P  
where P  
is the chip internal power (I xV  
)
D
INT  
PORT  
INT  
DD DD  
and P  
is the port power dissipation determined by the user.  
PORT  
2. The average chip-junction temperature can be obtained from the formula T = T + P x R .  
J
A
D
thJA  
128/135  
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
15 DEVICE CONFIGURATION AND ORDERING INFORMATION  
Each device is available for production in user pro-  
grammable versions (Flash) as well as in factory  
coded versions (ROM). Flash devices are shipped  
to customers with a default content (FFh), while  
ROM factory coded parts contain the code sup-  
plied by the customer. This implies that Flash de-  
vices have to be configured by the customer using  
the Option Bytes while the ROM devices are facto-  
ry-configured.  
USER OPTION BYTE 1  
Bit 7 = CFC Clock filter control on/off  
This option bit enables or disables the clock filter  
(CF) features.  
0: Clock filter enabled  
1: Clock filter disabled  
Bit 6:4 = OSC[2:0] Oscillator selection  
These three option bits can be used to select the  
main oscillator as shown in Table 24.  
Bit 3:2 = LVD[1:0] Low voltage detection selection  
These option bits enable the LVD block with a se-  
lected threshold as shown in Table 25.  
15.1 OPTION BYTES  
The two option bytes allow the hardware configu-  
ration of the microcontroller to be selected.  
Bit 1 = WDG HALT Watchdog and halt mode  
This option bit determines if a RESET is generated  
when entering HALT mode while the Watchdog is  
active.  
0: No Reset generation when entering Halt mode  
1: Reset generation when entering Halt mode  
The option bytes have no address in the memory  
map and can be accessed only in programming  
mode (for example using a standard ST7 program-  
ming tool). The default content of the Flash is fixed  
to FFh.  
In masked ROM devices, the option bytes are  
fixed in hardware by the ROM code (see option  
list).  
Bit 0 = WDG SW Hardware or software watchdog  
This option bit selects the watchdog type.  
0: Hardware (watchdog always enabled)  
1: Software (watchdog to be enabled by software)  
USER OPTION BYTE 0  
Table 24. Main Oscillator Configuration  
Bit 7:2 = Reserved, must always be 1.  
Selected Oscillator  
External Clock (Standby)  
~4 MHz Internal RC  
OSC2 OSC1 OSC0  
Bit 1 = EXTIT External Interrupt Configuration.  
This option bit allows the external interrupt map-  
ping to be configured as shown in Table 23.  
1
1
1
0
0
0
0
1
1
0
1
1
0
0
1
0
X
1
0
1
0
1~14 MHz External RC  
Table 23. External Interrupt Configuration  
Low Power Resonator (LP)  
Medium Power Resonator (MP)  
Medium Speed Resonator (MS)  
High Speed Resonator (HS)  
External IT0  
External IT1  
EXTIT  
Ports PB7-PB0  
Ports PC5-PC0  
Ports PA7-PA0  
1
Ports PA7-PA0  
Ports PC5-PC0  
Ports PB7-PB0  
0
Table 25. LVD Threshold Configuration  
Configuration  
LVD1 LVD0  
Bit 0 = FMP Full memory protection.  
This option bit enables or disables external access  
to the internal program memory (readout protec-  
tion). Clearing this bit causes the erasing (by over-  
writing with the currently latched values) of the  
whole memory (not including the option bytes).  
0: Program memory not readout protected  
LVD Off  
1
1
0
0
1
0
1
0
Highest Voltage Threshold (4.50V)  
Medium Voltage Threshold (4.05V)  
Lowest Voltage Threshold (3.45V)  
1: Program memory readout protected  
USER OPTION BYTE 0  
USER OPTION BYTE 1  
7
0
7
0
OSC OSC OSC  
WDG WDG  
HALT SW  
Reserved  
EXTIT FMP CFC  
LVD1 LVD0  
2
1
0
Default  
Value  
1
1
1
1
1
1
1
0
1
1
1
0
1
1
1
1
129/135  
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
15.2 DEVICE ORDERING INFORMATION AND TRANSFER OF CUSTOMER CODE  
Customer code is made up of the ROM contents  
and the list of the selected options (if any). The  
ROM contents are to be sent on diskette, or by  
electronic means, with the S19 hexadecimal file  
generated by the development tool. All unused  
bytes must be set to FFh.  
The selected options are communicated to  
STMicroelectronics using the correctly completed  
OPTION LIST appended.  
The STMicroelectronics Sales Organization will be  
pleased to provide detailed information on con-  
tractual points.  
Figure 97. ROM Factory Coded Device Types  
DEVICE PACKAGE TEMP. RANGE / XXX  
Code name (defined by STMicroelectronics)  
A = -40 to +85°C  
B = -40 to +105°C  
C = -40 to +125°C  
M = Plastic SOIC  
ST72104G1, ST72104G2,  
ST72215G2, ST72216G1,  
ST72254G1, ST72254G2  
Figure 98. Flash User Programmable Device Types  
DEVICE PACKAGE TEMP. RANGE  
A = -40 to +85°C  
B = -40 to +105°C  
C = -40 to +125°C  
M = Plastic SOIC  
ST72C104G1, ST72C104G2,  
ST72C215G2, ST72C216G1,  
ST72C254G1, ST72C254G2  
130/135  
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
TRANSFER OF CUSTOMER CODE (Cont’d)  
MICROCONTROLLER OPTION LIST  
Customer  
Address  
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  
Contact  
Phone No  
Reference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  
Device:  
[ ] ST72104G1 (4KB)  
[ ] ST72104G2 (8KB)  
[ ] ST72215G2 (4KB) [ ] ST72254G1 (4KB)  
[ ] ST72216G1 (8KB) [ ] ST72254G2 (8KB)  
Package:  
Marking:  
[ ] SO28  
[ ] Tape & Reel  
[ ] Tube  
[ ] Standard Marking  
[ ] Special Marking SO28 (max. 13 Chars.):  
_ _ _ _ _ _ _ _ _ _ _ _ _  
Authorized characters are letters, digits, ‘.’, ‘-’, ‘/’ and spaces only. Please consult your lo-  
cal STMicroelectronics sales office for other marking details if required.  
External Interrupt:  
[ ] IT0 interrupt vector Port A, IT1 interrupt vector Port B & C  
[ ] IT0 interrupt vector Port A & C, IT1 interrupt vector Port B  
Temperature Range:  
[ ] -40°C to +85°C  
[ ] Resonator:  
[ ] -40°C to +105°C  
[ ] -40°C to +125°C  
Clock Source Selection:  
[ ] LP: Low power resonator (1 to 2 MHz)  
[ ] MP: Medium power resonator (2 to 4 MHz)  
[ ] MS: Medium speed resonator (4 to 8 MHz)  
[ ] HS: High speed resonator (8 to 16 MHz)  
[ ] Internal  
[ ] RC Network:  
[ ] External Clock  
[ ] Disabled  
[ ] External  
Clock Security System:  
[ ] Enabled  
Watchdog Selection:  
Halt when Watchdog on:  
[ ] Software Activation [ ] Hardware Activation  
[ ] Reset  
[ ] No reset  
[ ] Enabled  
[ ] Enabled:  
Readout Protection:  
LVD Reset  
[ ] Disabled  
[ ] Disabled  
[ ] Highest threshold  
[ ] Medium threshold  
[ ] Lowest threshold  
Comments : . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  
Supply Operating Range in the application: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  
Notes:  
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  
Signature:  
131/135  
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
15.3 DEVELOPMENT TOOLS  
STmicroelectronics offers a range of hardware  
and software development tools for the ST7 micro-  
controller family. Full details of tools available for  
the ST7 from third party manufacturers can be ob-  
tained from the STMicroelectronics Internet site.  
STMicroelectronics Tools  
Three types of development tool are offered by  
ST; all of them connect to a PC via a parallel (LPT)  
port (see Table 26 and Table 27 for more details).  
Third Party Tools  
ACTUM  
BP  
COSMIC  
CMX  
DATA I/O  
HITEX  
HIWARE  
ISYSTEM  
KANDA  
LEAP  
Tools from these manufacturers include C compli-  
ers, emulators and gang programmers.  
Table 26. STMicroelectronics Tool Features  
1)  
Tool  
In-Circuit Emulation  
Yes. (Same features as  
HDS2 emulator but without Yes (DIP packages only)  
logic analyzer)  
Programming Capability  
Software Included  
ST7 CD ROM with:  
2)  
ST7 Development Kit  
– ST7 Assembly toolchain  
– STVD7 and WGDB7 powerful  
Source Level Debugger for Win  
3.1, Win 95 and NT  
Yes, powerful emulation  
features including trace/  
logic analyzer  
ST7 HDS2 Emulator  
No  
– C compiler demo versions  
– ST Realizer for Win 3.1 and  
Win95  
– Windows Programming Tools  
for Win 3.1, Win 95 and NT  
ST7 Programming Board No  
Yes (All packages)  
Notes:  
1. In-Situ Programming (ISP) interface for Flash devices.  
2. Tool equipped with a DIP socket only; an adapter may be required to program devices in SO packages.  
Table 27. Dedicated STMicroelectronics Development Tools  
Supported Products  
ST7 Development Kit  
ST7 HDS2 Emulator  
ST7 Programming Board  
ST72254G1, ST72C254G1  
ST72254G2, ST72C254G2  
ST72215G2, ST72C215G2  
ST72216G1, ST72C216G1  
ST72104G1, ST72C104G1,  
ST72104G2, ST72C104G2  
ST7MDT1-EPB2/EU  
ST7MDT1-EPB2/US  
ST7MDT1-EPB2/UK  
ST7MDT1-DVP2  
ST7MDT1-EMU2B  
132/135  
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
DEVELOPMENT TOOLS (Cont’d)  
15.3.1 Package/Socket Footprint Proposal  
Table 28. Suggested List of SO28 Socket Types  
Same  
Footprint  
Package / Probe  
Adaptor / Socket Reference  
Socket Type  
ENPLAS  
OTS-28-1.27-04  
IC51-0282-334-1  
Open Top  
SO28  
YAMAICHI  
Clamshell  
EMU PROBE  
Adapter from SO28 to SDIP32 footprint (delivered with emulator)  
X
SMD to SDIP  
15.4 ST7 APPLICATION NOTES  
All relevant ST7 application notes can be found on  
www.st.com.  
133/135  
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
16 SUMMARY OF CHANGES  
Description of the changes between the current release of the specification and the previous one.  
Date  
Rev.  
Main changes  
Initial release of the ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
datasheet  
The ST72xxxG-Auto datasheet was created from the ST72104G, ST72215G, ST72216G,  
ST72254G Preliminary Data datasheet, revision 2.6 dated November 2000, with the following  
changes:  
Changed document title and description on page 1  
Removed SDIP32 package outline from page 1  
“Device Summary” on page 1:  
- changed operating temperature range  
- removed SDIP32 package  
Section 1 "INTRODUCTION" on page 6: Added ‘-Auto’ extension to ST72xxxG numbers in first  
paragraph  
Section 2 "PIN DESCRIPTION" on page 7: Removed Figure "32-Pin SDIP Package Pinout"  
Table 1 on page 8: Removed SDIP32 pin number column  
Section 6 "SUPPLY, RESET AND CLOCK MANAGEMENT" on page 17: Added ‘-Auto’ exten-  
sion to ST72xxxG numbers in first paragraph  
“MULTI-OSCILLATOR (MO)” on page 21: Modified description of external and internal RC  
Section 11.1.3 "Functional Description" on page 39: Replaced 500ns with 30µs at end of sec-  
ond paragraph to be in line with spec given in Section 13.9.1 "Asynchronous RESET Pin" on  
page 119  
Section 12.1.4 "Indexed (No Offset, Short, Long)" on page 90: Replaced “The indirect address-  
ing mode consists of” with “The indexed addressing mode consists of” in second paragraph  
Section 13.2.1 "Voltage Characteristics" on page 96: Changed V ratings and values  
IN  
Section 13.3.1 "General Operating Conditions" on page 97: Modified ambient temperature  
range conditions to include only automotive device suffix versions  
Section 13.5.3.2 "Typical Ceramic Resonators" on page 106: Removed Table “Typical Ceram-  
ic Resonators for General Purpose Applications”  
29-Oct-2007  
1
Changed titles of Figure 81 on page 117 and Figure 84 on page 118  
Figure 91.SPI Slave Timing Diagram with CPHA=1 1): Corrected ‘CPHA=0’ to read ‘CPHA=1’  
for SCK  
INPUT  
Section 14.1 "PACKAGE MECHANICAL DATA" on page 128:  
- removed Figure “32-Pin Shrink Plastic Dual In Line Package”  
- added Section 14.2 "ECOPACK®" on page 128  
- removed Section "SOLDERING AND GLUEABILITY INFORMATION"  
Section 14.3 "THERMAL CHARACTERISTICS" on page 128: Removed SDIP32 package  
from package thermal resistance ratings  
Figure 97.ROM Factory Coded Device Types: Modified to include only automotive device tem-  
perature versions and removed DIP package  
Figure 98.Flash User Programmable Device Types: Modified to include only automotive de-  
vice temperature versions and removed DIP package  
Section 15.1 "OPTION BYTES" on page 129: Changed description of FMP option bit  
“MICROCONTROLLER OPTION LIST” on page 131: Modified to include only automotive de-  
vice temperature versions and removed DIP package  
Section 15.3 "DEVELOPMENT TOOLS" on page 132: Removed link ‘http//mcu.st.com’ from  
the end of the first paragraph  
Table 26, “STMicroelectronics Tool Features,” on page 132: Added footnote 2  
Section 15.3.1 "Package/Socket Footprint Proposal" on page 133: Removed Table “Suggest-  
ed List of SDIP32 Socket Types”  
Section 15.4 "ST7 APPLICATION NOTES" on page 133: Removed Table “ST7 Application  
Notes”  
Updated disclaimer on last page to include a mention about the use of ST products in automo-  
tive applications  
134/135  
ST72104Gx-Auto, ST72215Gx-Auto, ST72216Gx-Auto, ST72254Gx-Auto  
Please Read Carefully:  
Information in this document is provided solely in connection with ST products. STMicroelectronics NV and its subsidiaries (“ST”) reserve the  
right to make changes, corrections, modifications or improvements, to this document, and the products and services described herein at any  
time, without notice.  
All ST products are sold pursuant to ST’s terms and conditions of sale.  
Purchasers are solely responsible for the choice, selection and use of the ST products and services described herein, and ST assumes no  
liability whatsoever relating to the choice, selection or use of the ST products and services described herein.  
No license, express or implied, by estoppel or otherwise, to any intellectual property rights is granted under this document. If any part of this  
document refers to any third party products or services it shall not be deemed a license grant by ST for the use of such third party products  
or services, or any intellectual property contained therein or considered as a warranty covering the use in any manner whatsoever of such  
third party products or services or any intellectual property contained therein.  
UNLESS OTHERWISE SET FORTH IN ST’S TERMS AND CONDITIONS OF SALE ST DISCLAIMS ANY EXPRESS OR IMPLIED  
WARRANTY WITH RESPECT TO THE USE AND/OR SALE OF ST PRODUCTS INCLUDING WITHOUT LIMITATION IMPLIED  
WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE (AND THEIR EQUIVALENTS UNDER THE LAWS  
OF ANY JURISDICTION), OR INFRINGEMENT OF ANY PATENT, COPYRIGHT OR OTHER INTELLECTUAL PROPERTY RIGHT.  
UNLESS EXPRESSLY APPROVED IN WRITING BY AN AUTHORIZED ST REPRESENTATIVE, ST PRODUCTS ARE NOT  
RECOMMENDED, AUTHORIZED OR WARRANTED FOR USE IN MILITARY, AIR CRAFT, SPACE, LIFE SAVING, OR LIFE  
SUSTAINING APPLICATIONS, NOR IN PRODUCTS OR SYSTEMS WHERE FAILURE OR MALFUNCTION MAY RESULT IN  
PERSONAL INJURY, DEATH, OR SEVERE PROPERTY OR ENVIRONMENTAL DAMAGE. ST PRODUCTS WHICH ARE NOT  
SPECIFIED AS "AUTOMOTIVE GRADE" MAY ONLY BE USED IN AUTOMOTIVE APPLICATIONS AT USER’S OWN RISK.  
Resale of ST products with provisions different from the statements and/or technical features set forth in this document shall immediately void  
any warranty granted by ST for the ST product or service described herein and shall not create or extend in any manner whatsoever, any  
liability of ST.  
ST and the ST logo are trademarks or registered trademarks of ST in various countries.  
Information in this document supersedes and replaces all information previously supplied.  
The ST logo is a registered trademark of STMicroelectronics. All other names are the property of their respective owners.  
© 2007 STMicroelectronics - All rights reserved  
STMicroelectronics group of companies  
Australia - Belgium - Brazil - Canada - China - Czech Republic - Finland - France - Germany - Hong Kong - India - Israel - Italy - Japan -  
Malaysia - Malta - Morocco - Singapore - Spain - Sweden - Switzerland - United Kingdom - United States of America  
www.st.com  
135/135  

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8-BIT MCU WITH SINGLE VOLTAGE FLASH MEMORY, ADC, 16-BIT TIMERS, SPI, IC INTERFACES

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STMICROELECTR

ST72254G2B7

8-BIT MCU WITH SINGLE VOLTAGE FLASH MEMORY. ADC. 16-BIT TIMERS. SPI.

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ETC