Datasheet

244
AT32UC3A
24.13.7 Reversal after a Repeated Start
24.13.7.1 Reversal of Read to Write
The master initiates the communication by a read command and finishes it by a write command.
Figure 24-28 on page 244 describes the repeated start + reversal from Read to Write mode.
Figure 24-28. Repeated Start + Reversal from Read to Write Mode
1. TXCOMP is only set at the end of the transmission because after the repeated start, SADR is detected again.
24.13.7.2 Reversal of Write to Read
The master initiates the communication by a write command and finishes it by a read com-
mand.Figure 24-29 on page 244 describes the repeated start + reversal from Write to Read
mode.
Figure 24-29. Repeated Start + Reversal from Write to Read Mode
Notes: 1. In this case, if THR has not been written at the end of the read command, the clock is automatically stretched before the
ACK.
2. TXCOMP is only set at the end of the transmission because after the repeated start, SADR is detected again.
S SADR R ADATA0A DATA1
SADRSr
NA
W A DATA2 A DATA3 A P
Cleared after read
DATA0 DATA1
DATA2 DATA3
SVACC
SVREAD
TWD
TWI_THR
TWI_RHR
EOSACC
TXRDY
RXRDY
TXCOMP
As soon as a START is detected
S SADR W ADATA0A DATA1
SADRSr
A
R A DATA2 A DATA3 NA P
Cleared after read
DATA0
DATA2 DATA3
DATA1
TXCOMP
TXRDY
RXRDY
As soon as a START is detected
Read TWI_RHR
SVACC
SVREAD
TWD
TWI_RHR
TWI_THR
EOSACC
32058K
AVR32-01/12