Datasheet

252
AT32UC3A
24.14.7 TWI Status Register
Name: SR
Access: Read-only
Reset Value: 0x0000F009
• TXCOMP: Transmission Completed (automatically set / reset)
TXCOMP used in Master mode:
0 = During the length of the current frame.
1 = When both holding and shifter registers are empty and STOP condition has been sent.
TXCOMP behavior in Master mode can be seen in Figure 24-8 on page 225 and in Figure 24-10 on page 226.
TXCOMP used in Slave mode:
0 = As soon as a Start is detected.
1 = After a Stop or a Repeated Start + an address different from SADR is detected.
TXCOMP behavior in Slave mode can be seen in Figure 24-26 on page 242, Figure 24-27 on page 243, Figure 24-28 on
page 244 and Figure 24-29 on page 244.
• RXRDY: Receive Holding Register Ready (automatically set / reset)
0 = No character has been received since the last RHR read operation.
1 = A byte has been received in the RHR since the last read.
RXRDY behavior in Master mode can be seen in Figure 24-10 on page 226.
RXRDY behavior in Slave mode can be seen in Figure 24-24 on page 241, Figure 24-27 on page 243, Figure 24-28 on
page 244 and Figure 24-29 on page 244.
• TXRDY: Transmit Holding Register Ready (automatically set / reset)
TXRDY used in Master mode:
0 = The transmit holding register has not been transferred into shift register. Set to 0 when writing into THR register.
1 = As soon as a data byte is transferred from THR to internal shifter or if a NACK error is detected, TXRDY is set at the
same time as TXCOMP and NACK. TXRDY is also set when MSEN is set (enable TWI).
TXRDY behavior in Master mode can be seen in Figure 24-8 on page 225.
31 30 29 28 27 26 25 24
– – – – – – – –
23 22 21 20 19 18 17 16
– – – – – – – –
15 14 13 12 11 10 9 8
TXBUFE RXBUFF ENDTX ENDRX EOSACC SCLWS ARBLST NACK
7 6 5 4 3 2 1 0
– OVRE GACC SVACC SVREAD TXRDY RXRDY TXCOMP
32058K
AVR32-01/12