SAM3SD8C Atmel Corporation, SAM3SD8C Datasheet - Page 637

• Manufacturer Part Number: SAM3SD8C
• Manufacturer: Atmel Corporation

TXRDY used in Slave mode:
0 = As soon as data is written in the TWI_THR, until this data has been transmitted and acknowledged (ACK or NACK).
1 = It indicates that the TWI_THR is empty and that data has been transmitted and acknowledged.
If TXRDY is high and if a NACK has been detected, the transmission will be stopped. Thus when TRDY = NACK = 1, the
programmer must not fill TWI_THR to avoid losing it.
TXRDY behavior in Slave mode can be seen in
page 627
• SVREAD: Slave Read (automatically set / reset)
This bit is only used in Slave mode. When SVACC is low (no Slave access has been detected) SVREAD is irrelevant.
0 = Indicates that a write access is performed by a Master.
1 = Indicates that a read access is performed by a Master.
SVREAD behavior can be seen in
Figure 29-31 on page
• SVACC: Slave Access (automatically set / reset)
This bit is only used in Slave mode.
0 = TWI is not addressed. SVACC is automatically cleared after a NACK or a STOP condition is detected.
1 = Indicates that the address decoding sequence has matched (A Master has sent SADR). SVACC remains high until a
NACK or a STOP condition is detected.
SVACC behavior can be seen in
ure 29-31 on page
• GACC: General Call Access (clear on read)
This bit is only used in Slave mode.
0 = No General Call has been detected.
1 = A General Call has been detected. After the detection of General Call, if need be, the programmer may acknowledge
this access and decode the following bytes and respond according to the value of the bytes.
GACC behavior can be seen in
• 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 (clear on read)
NACK used in Master mode:
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.
11090A–ATARM–10-Feb-12
11090A–ATARM–10-Feb-12
and
Figure 29-31 on page
627.
627.
Figure 29-27 on page
Figure 29-25 on page
Figure 29-25 on page
627.
Figure 29-25 on page
624.
623,
623,
Figure 29-26 on page
Figure 29-26 on page
623,
Figure 29-28 on page
623,
623,
Figure 29-30 on page 627
Figure 29-30 on page 627
SAM3S8/SD8
SAM3S8/SD8
625,
Figure 29-30 on
and
Fig-
and
637
637