ATMEGA48V_09 ATMEL [ATMEL Corporation], ATMEGA48V_09 Datasheet - Page 232

• Manufacturer Part Number: ATMEGA48V_09
• Description: 8-bit Microcontroller with 8K Bytes In-System Programmable Flash
• Manufacturer: ATMEL [ATMEL Corporation]

Table 21-5.
232
Status Code
(TWSR)
Prescaler
Bits
are 0
0xA8
0xB0
0xB8
0xC0
0xC8
ATmega48/88/168
Status of the 2-wire Serial Bus
and 2-wire Serial Interface Hard-
ware
Own SLA+R has been received;
ACK has been returned
Arbitration lost in SLA+R/W as
Master; own SLA+R has been
received; ACK has been returned
Data byte in TWDR has been
transmitted; ACK has been
received
Data byte in TWDR has been
transmitted; NOT ACK has been
received
Last data byte in TWDR has been
transmitted (TWEA = “0”); ACK
has been received
Status Codes for Slave Transmitter Mode
To/from TWDR
Load data byte or
Load data byte
Load data byte or
Load data byte
Load data byte or
Load data byte
No TWDR action or
No TWDR action or
No TWDR action or
No TWDR action
No TWDR action or
No TWDR action or
No TWDR action or
No TWDR action
Application Software Response
STA
X
X
X
X
X
X
0
0
1
1
0
0
1
1
STO
0
0
0
0
0
0
0
0
0
0
0
0
0
0
To TWCR
TWIN
T
1
1
1
1
1
1
1
1
1
1
1
1
1
1
TWE
A
0
1
0
1
0
1
0
1
0
1
0
1
0
1
Next Action Taken by TWI Hardware
Last data byte will be transmitted and NOT ACK should
be received
Data byte will be transmitted and ACK should be re-
ceived
Last data byte will be transmitted and NOT ACK should
be received
Data byte will be transmitted and ACK should be re-
ceived
Last data byte will be transmitted and NOT ACK should
be received
Data byte will be transmitted and ACK should be re-
ceived
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
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
2545R–AVR–07/09