
Other master continues
S
SLA/W
A
DATA
A
P
Successful
transmission to a
slave receiver
UCTXIFG=1
DATA
DATA
A
A
UCTXSTP=1
Next transfer started
with a repeated start
condition
DATA
A
S
SLA/W
1) UCTR=1 (Transmitter)
2) UCTXSTT=1
DATA
A
S
SLA/R
1) UCTR=0 (Receiver)
2) UCTXSTT=1
Not acknowledge
received after slave
address
P
S
SLA/W
S
SLA/R
UCTXSTP=1
1) UCTR=1 (Transmitter)
2) UCTXSTT=1
1) UCTR=0 (Receiver)
2) UCTXSTT=1
Arbitration lost in
slave address or
data byte
A
A
Other master continues
Arbitration lost and
addressed as slave
Other master continues
A
UCALIFG=1
UCMST=0
UCTR=0 (Receiver)
UCSTTIFG=1
(UCGC=1 if general call)
USCI continues as Slave Receiver
Not acknowledge
received after a data
byte
UCTXSTT=0
UCTXSTP=0
UCTXSTP=0
UCALIFG=1
UCMST=0
Bus stalled (SCL held low)
until data available
Write data to UCBxTXBUF
1) UCTR=1 (Transmitter)
2) UCTXSTT=1
UCTXIFG=1
UCBxTXBUF discarded
UCTXSTT=0
UCNACKIFG=1
UCBxTXBUF discarded
UCTXIFG=1
UCBxTXBUF discarded
UCNACKIFG=1
UCBxTXBUF discarded
UCALIFG=1
UCMST=0
eUSCI_B Operation – I
2
C Mode
Figure 20-12. I
2
C Master Transmitter Mode
543
SLAU272C – May 2011 – Revised November 2013
Enhanced Universal Serial Communication Interface (eUSCI) – I
2
C Mode
Copyright © 2011–2013, Texas Instruments Incorporated