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ST7 S/W IMPLEMENTATION OF I2C BUS MASTER

3 COMMUNICATION FRAMES

The communication protocol between the master and the slave is given in Figure 2. For more

details, please refer to the ST7 datasheet.

Figure 2. I2C Communication Protocol

4 FLOWCHARTS

Figure 3. Communication Application Flowchart

ACK

START E2PROM @

SUB @

ACK

DATA 1

ACK

DATA 2

ACK

DATA N-1

DATA N

STOP

ACK

START E2PROM @

SUB @

ACK

DATA 1

ACK

DATA N

NACK STOP

ACK

START E2PROM @

ACK

Write data from ST7 to E2PROM

Read data from E2PROM to ST7

INITIATE TRANSMISSION

(START + addresses)

END OF

BUFFOUT?

yes

no

SEND NEXT TABLE DATA

INITIATE TRANSMISSION

(START+@+START+@lsb=1)

STOP CONDITION

Master transmitter

Master receiver

WAIT FOR NEXT DATA TO RECEIVE

LAST VALUE

TO RECEIVE?

no

yes

ACK?

yes

no

ACK?

yes

no

ACK?

no

yes

ACK

NON ACK

STOP CONDITION