Datasheet

ATmega48/88/168 Automotive [DATASHEET]
7530K–AVR–07/14
196
Table 19-6. Status Codes for Slave Receiver 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
0x60
Own SLA+W has been
received;
ACK has been returned
No TWDR action
or
No TWDR action
X
X
0
0
1
1
0
1
Data byte will be received and NOT ACK will
be returned
Data byte will be received and ACK will be
returned
0x68
Arbitration lost in SLA+R/W
as Master; own SLA+W has
been received; ACK has
been returned
No TWDR action
or
No TWDR action
X
X
0
0
1
1
0
1
Data byte will be received and NOT ACK will
be returned
Data byte will be received and ACK will be
returned
0x70
General call address has
been received; ACK has
been returned
No TWDR action
or
No TWDR action
X
X
0
0
1
1
0
1
Data byte will be received and NOT ACK will
be returned
Data byte will be received and ACK will be
returned
0x78
Arbitration lost in SLA+R/W
as Master; general call
address has been received;
ACK has been returned
No TWDR action
or
No TWDR action
X
X
0
0
1
1
0
1
Data byte will be received and NOT ACK will
be returned
Data byte will be received and ACK will be
returned
0x80
Previously addressed with
own SLA+W; data has been
received; ACK has been
returned
Read data byte
or
Read data byte
X
X
0
0
1
1
0
1
Data byte will be received and NOT ACK will
be returned
Data byte will be received and ACK will be
returned
0x88 Previously addressed with
own SLA+W; data has been
received; NOT ACK has
been returned
Read data byte
or
Read data byte
or
Read data byte
or
Read data byte
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
0x90 Previously addressed with
general call; data has been
received; ACK has been
returned
Read data byte
or
Read data byte
X
X
0
0
1
1
0
1
Data byte will be received and NOT ACK will
be returned
Data byte will be received and ACK will be
returned
0x98 Previously addressed with
general call; data has been
received; NOT ACK has
been returned
Read data byte
or
Read data byte
or
Read data byte
or
Read data byte
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