UPSD3354DV-40U6 Datasheet, PDF (135/272 Pages) STMicroelectronics – fast 8032 MCU with programmable logic

UPSD33xx
I²C interface
Set bus START condition sampling
● SFR S1SETUP[7:0] = number of samples
Enable individual I2C interrupt and set priority
● SFR IEA.I2C = 1
● SFR IPA.I2C = 1 if high priority is desired
Set the Device address for Slave mode
● SFR S1ADR = XXh, desired address
Enable SIOE (as Slave) to return an ACK signal
● SFR S1CON.AA = 1
Master-transmitter
Disable all interrupts
● SFR IE.EA = 0
Set pointer to global data xmit buffer, set count
) ^{● *xmit_buf = *pointer to data}
t(s ^{● buf_length = number of bytes to xmit}
c _{Set global variables to indicate Master-Xmitter}
du ● I2C_master = 1, I2C_xmitter = 1
ro _{Disable Master from returning an ACK}
P _{● SFR S1CON.AA = 0}
te _{Enable I2C SIOE}
le _{● SFR S1CON.INI1 = 1}
so _{Transmit Address and R/W bit = 0 to Slave}
Ob ^{● Is bus not busy? (SFR S1STA.BBUSY = 0?)}
- _{<If busy, then test until not busy>}
t(s) ^{● SFR S1DAT[7:0] = Load Slave Address & FEh}
● SFR S1CON.STA = 1, send START on bus
uc <bus transmission begins>
rod ^{Enable All Interrupts and go do something else}
● SFR IE.EA = 1
te ^{P Master-receiver}
le_{Disable all interrupts}
so _{● SFR IE.EA = 0}
Ob ^{Set pointer to global data recv buffer, set count}
● *recv_buf = *pointer to data
● buf_length = number of bytes to recv
Set global variables to indicate Master-Xmitter
● I2C_master = 1, I2C_xmitter = 0
Doc ID 9685 Rev 7
135/272