Datasheet

199
ATmega48/88/168 Automotive [DATASHEET]
7530K–AVR–07/14
Table 19-7. Status Codes for Slave Transmitter Mode
Status
Code
(TWSR)
Prescaler
Bits are 0
Status of the 2-wire Serial
Bus and 2-wire Serial
Interface Hardware
Application Software Response
Next Action Taken by TWI Hardware
To/from TWDR To TWCR
STA STO TWINT TWEA
0xA8 Own SLA+R has been
received;
ACK has been returned
Load data byte
or
Load data byte
X
X
0
0
1
1
0
1
Last data byte will be transmitted and NOT
ACK should be received
Data byte will be transmitted and ACK should
be received
0xB0 Arbitration lost in SLA+R/W
as Master; own SLA+R has
been received; ACK has
been returned
Load data byte
or
Load data byte
X
X
0
0
1
1
0
1
Last data byte will be transmitted and NOT
ACK should be received
Data byte will be transmitted and ACK should
be received
0xB8 Data byte in TWDR has
been transmitted; ACK has
been received
Load data byte
or
Load data byte
X
X
0
0
1
1
0
1
Last data byte will be transmitted and NOT
ACK should be received
Data byte will be transmitted and ACK should
be received
0xC0 Data byte in TWDR has
been transmitted; NOT ACK
has been received
No TWDR action
or
No TWDR action
or
No TWDR action
or
No TWDR action
0
0
1
1
0
0
0
0
1
1
1
1
0
1
0
1
Switched to the not addressed slave mode;
no recognition of own SLA or GCA
Switched to the not addressed slave mode;
own SLA will be recognized; GCA will be
recognized if TWGCE = “1”
Switched to the not addressed slave mode;
no recognition of own SLA or GCA; a START
condition will be transmitted when the bus
becomes free
Switched to the not addressed slave mode;
own SLA will be recognized; GCA will be
recognized if TWGCE = “1”; a START
condition will be transmitted when the bus
becomes free
0xC8 Last data byte in TWDR has
been transmitted (TWEA =
“0”); ACK has been received
No TWDR action
or
No TWDR action
or
No TWDR action
or
No TWDR action
0
0
1
1
0
0
0
0
1
1
1
1
0
1
0
1
Switched to the not addressed slave mode;
no recognition of own SLA or GCA
Switched to the not addressed slave mode;
own SLA will be recognized; GCA will be
recognized if TWGCE = “1”
Switched to the not addressed slave mode;
no recognition of own SLA or GCA; a START
condition will be transmitted when the bus
becomes free
Switched to the not addressed slave mode;
own SLA will be recognized; GCA will be
recognized if TWGCE = “1”; a START
condition will be transmitted when the bus
becomes free