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SAM7X256_14 Datasheet, PDF (287/662 Pages) ATMEL Corporation – ARM-based Flash MCU | |||
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29.6.5 TWI Status Register
Register Name:
Access Type:
TWI_SR
Read-only
31
30
29
28
27
26
25
24
â
â
â
â
â
â
â
â
23
22
21
20
19
18
17
16
â
â
â
â
â
â
â
â
15
14
13
12
11
10
â
â
â
â
â
â
9
8
â
NACK
7
6
5
4
3
2
1
0
â
OVRE
â
â
â
TXRDY
RXRDY
TXCOMP
⢠TXCOMP: Transmission Completed
0 = During the length of the current frame.
1 = When both holding and shift registers are empty and STOP condition has been sent, or when MSEN is set (enable TWI).
⢠RXRDY: Receive Holding Register Ready
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.
⢠TXRDY: Transmit Holding Register Ready
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 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).
⢠OVRE: Overrun Error (clear on read)
This bit is only used in Master mode.
0 = TWI_RHR has not been loaded while RXRDY was set
1 = TWI_RHR has been loaded while RXRDY was set. Reset by read in TWI_SR when TXCOMP is set.
⢠NACK: Not Acknowledged
0 = Each data byte has been correctly received by the far-end side TWI slave component.
1 = A data byte has not been acknowledged by the slave component. Set at the same time as TXCOMP. Reset after read.
SAM7X Series [DATASHEET]
6120KâATARMâ11-Feb-14
287
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