ATmega88PA Automotive Atmel Corporation, ATmega88PA Automotive Datasheet - Page 230

• Manufacturer Part Number: ATmega88PA Automotive
• Manufacturer: Atmel Corporation

Table 22-4.
230
Status Code
Prescaler
(TWSR)
are 0
0x08
0x10
0x38
0x40
0x48
0x50
0x58
Bits
Atmel ATmega48PA/88PA/168PA [Preliminary]
Serial Interface Hardware
Arbitration lost in SLA+R or
Status codes for Master Receiver Mode
ACK has been received
ACK has been returned
A START condition has
Serial Bus and 2-wire
Status of the 2-wire
NOT ACK has been
NOT ACK has been
Data byte has been
Data byte has been
A repeated START
condition has been
SLA+R has been
SLA+R has been
been transmitted
NOT ACK bit
transmitted;
transmitted;
transmitted
received;
received;
received
returned
A REPEATED START condition is generated by writing the following value to TWCR:
After a repeated START condition (state 0x10) the 2-wire Serial Interface can access the
same Slave again, or a new Slave without transmitting a STOP condition. Repeated START
enables the Master to switch between Slaves, Master Transmitter mode and Master Receiver
mode without losing control over the bus.
TWCR
value
No TWDR action or
No TWDR action or
No TWDR action or
No TWDR action or
Read data byte or
Read data byte or
Read data byte or
No TWDR action
No TWDR action
No TWDR action
To/from TWDR
Load SLA+R or
Read data byte
Read data byte
Load SLA+W
Load SLA+R
TWINT
1
Application Software Response
TWEA
X
STA
0
0
0
0
1
0
0
1
0
1
0
0
1
0
1
STO
TWSTA
0
0
0
0
0
0
0
0
1
1
0
0
0
1
1
To TWCR
1
TWINT TWEA
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
TWSTO
0
X
X
X
X
X
X
X
X
X
X
X
0
1
0
1
Next Action Taken by TWI Hardware
SLA+R will be transmitted
ACK or NOT ACK will be received
SLA+R will be transmitted
ACK or NOT ACK will be received
SLA+W will be transmitted
Logic will switch to Master Transmitter mode
2-wire Serial Bus will be released and not
addressed Slave mode will be entered
A START condition will be transmitted when the
bus
becomes free
Data byte will be received and NOT ACK will be
returned
Data byte will be received and ACK will be
returned
Repeated START will be transmitted
STOP condition will be transmitted and TWSTO
Flag will be reset
STOP condition followed by a START condition
will be transmitted and TWSTO Flag will be reset
Data byte will be received and NOT ACK will be
returned
Data byte will be received and ACK will be
returned
Repeated START will be transmitted
STOP condition will be transmitted and TWSTO
Flag will be reset
STOP condition followed by a START condition
will be transmitted and TWSTO Flag will be reset
TWWC
X
TWEN
1
–
0
9223B–AVR–09/11
TWIE
X