at91sam9g20-cu ATMEL Corporation, at91sam9g20-cu Datasheet - Page 448

• Manufacturer Part Number: at91sam9g20-cu
• Description: At91 Arm Thumb Microcontrollers
• Manufacturer: ATMEL Corporation

31.10.6
Name:
Access:
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
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
page 440
• RXRDY: Receive Holding Register Ready (automatically set / reset)
0 = No character has been received since the last TWI_RHR read operation.
1 = A byte has been received in the TWI_RHR since the last read.
RXRDY behavior in Master mode can be seen in
RXRDY behavior in Slave mode can be seen in
page 440
• 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 TWI_THR register.
1 = As soon as a data byte is transferred from TWI_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
448
TXBUFE
31
23
15
–
–
7
–
AT91SAM9G20 Preliminary
and
and
TWI Status Register
TWI_SR
Read-only
Figure 31-31 on page
Figure 31-31 on page
RXBUFF
OVRE
30
22
14
–
–
6
ENDTX
GACC
440.
440.
29
21
13
–
–
5
Figure 31-8 on page
Figure 31-10 on page
Figure 31-26 on page
ENDRX
SVACC
Figure 31-28 on page
Figure 31-8 on page 421
28
20
12
–
–
4
EOSACC
SVREAD
27
19
11
–
–
3
421.
422.
436,
438,
and in
Figure 31-29 on page
Figure 31-29 on page
SCLWS
TXRDY
26
18
10
Figure 31-10 on page
–
–
2
ARBLST
RXRDY
25
17
–
–
9
1
439,
439,
6384B–ATARM–15-Dec-08
422.
Figure 31-30 on
Figure 31-30 on
TXCOMP
NACK
24
16
–
–
8
0