AN1713 Datasheet, PDF (1/4 Pages) STMicroelectronics – SMBus SLAVE DRIVER FOR ST7 I2C PERIPHERAL

AN1713
APPLICATION NOTE
SMBus SLAVE DRIVER FOR ST7 I2C PERIPHERAL
by Microcontroller Division Applications
INTRODUCTION
The goal of this application note is to implement the SMBus slave protocol using ST7 I2C. The
software of this application performs all SMBus bus protocols mentioned in SMBus v1.1. The
device chosen here is ST72F264 which has multi-master I2C capability.
The program described in this application note is in C language. The driver is compatible with
Metrowerks and Cosmic compilers.
1 CHARACTERISTICS
The main characteristics of this SMBus slave driver are:
s SMBus bus protocols: Quick command, Send/ Receive Byte, Write/ Read Byte, Write/ Read
Word, Write/ Read Block, Process Call Word/ Block
s Slave SMBus addressing
s CRC-8 Packet Error Checking
For more details please refer to the SMBus specification v1.1.
2 SMBus
The System Management Bus (SMBus) is a two-wire interface through which various system
component chips can communicate with each other and with the rest of the system. It is based
on the principles of operation of I2C.
2.1 Similarities of SMBus and I2C
s 2 wire bus protocol (1 Clk, 1 Data)
s Master-slave communication, Master provides clock
s Multi master capability
s SMBus data format similar to I2C 7-bit addressing format.
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