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ST7 S/W IMPLEMENTATION OF I2C BUS MASTER

Figure 5. Flowchart of the transmission function

The reception function is also based on a double shift: a shift of the “count” variable to call 8

times the function I2Cm_RxData (to receive the 8 bits of one data byte) and a shift of a buffer

into the I2Cm_RxData function to receive the data bit by bit on the LSB (refer to Figure 6).

SDA configured as output

count=1

I2C_DR=buffout[j]

shift of count

I2Cm_TxData

count overflows?

yes

no

wait Acknowledge

ACK ok?

yes

no

AF=1

END

j--

j=FF?

no

yes

j=nb