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I2C COMMUNICATION BETWEEN STR71X AND M24CXX EEPROM

3 STR71X/M24C08 COMMUNICATION APPLICATION

3.1 HARDWARE CONFIGURATION

Two M24C08 memory chips can be addressed by a microcontroller on the same two wire bus

by configuring the M24C08 input E2. In this application the M24C08 E0, E1 and E2 inputs are

tied to V3.3 via 10K resistor. The M24C08 is divided into four blocks defined by the two LSB

bits of the memory address defined on the following:

■

M24C08_Block0 ==> ADDRESS 0xA8

■

M24C08_Block1 ==> ADDRESS 0xAA

■

M24C08_Block2 ==> ADDRESS 0xAC

■

M24C08_Block3 ==> ADDRESS 0xAE

Figure 1. STR71x/M24C08 configuration

3.2 SOFTWARE IMPLEMENTATION

In this application note the software modules are developed in C language, with RVDK envi-

ronment.

The software implemented to manage read and write operations between the STR71x I2C

interface and the M24C08 is divided in three parts:

– Write: first, the program writes the contents of a predefined buffer to the memory starting

from address 0x00 of Block3,

M24C02

2

8

1

M24C04

4

4

2

M24C08

8

2

4

M24C016

16

1

8

Device

Size (Kbit)

Devices per Bus

Number of Blocks

STR71x

M24C08

E2

E0

V3.3

SDA

SCL

SDA

SCL

E1

10K

10K

10K

100

100

V3.3

2