UPSD3354DV-40U6 Datasheet, PDF (136/272 Pages) STMicroelectronics – fast 8032 MCU with programmable logic

I²C interface
UPSD33xx
Disable Master from returning an ACK
● SFR S1CON.AA = 0
Enable I2C SIOE
● SFR S1CON.INI1 = 1
Transmit Address and R/W bit = 1 to Slave
● Is bus not busy? (SFR S1STA.BBUSY = 0?)
<If busy, then test until not busy>
● SFR S1DAT[7:0] = Load Slave Address # 01h
● SFR S1CON.STA = 1, send START on bus
<bus transmission begins>
Enable All Interrupts and go do something else
● SFR IE.EA = 1
Slave-Transmitter
Disable all interrupts
t(s) ^{● SFR IE.EA = 0}
c Set pointer to global data xmit buffer, set count
u _{● *xmit_buf = *pointer to data}
rod ^{● buf_length = number of bytes to xmit}
P _{Set global variables to indicate Master-Xmitter}
te ^{● I2C_master = 0, I2C_xmitter = 1}
le _{Enable SIOE}
so ● SFR S1CON.INI1 = 1
b _{Prepare to Xmit first data byte}
- ^O ● SFR S1DAT[7:0] = xmit_buf[0]
t(s) ^{Enable All Interrupts and go do something else}
● SFR IE.EA = 1
duc ^{Slave-Receiver}
ro _{Disable all interrupts}
P _{● SFR IE.EA = 0}
te_{Set pointer to global data recv buffer, set count}
le_{● *recv_buf = *pointer to data}
so _{● buf_length = number of bytes to recv}
Ob ^{Set global variables to indicate Master-Xmitter}
● I2C_master = 0, I2C_xmitter = 0
Enable SIOE
● SFR S1CON.INI1 = 1
Enable All Interrupts and go do something else
● SFR IE.EA = 1
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Doc ID 9685 Rev 7