AT94K Datasheet, PDF (142/192 Pages) ATMEL Corporation – 5K - 40K Gates of AT40K FPGA with 8-bit Microcontroller, up to 36K Bytes of SRAM and On-chip JTAG ICE

Table 42. Status Codes for Slave Receiver Mode
Status
Code
(TWSR)
Status of the 2-wire
Serial Bus and 2-wire
Serial Hardware
Application Software Response
To TWCR
To/From TWDR
STA STO TWINT
$60
Own SLA+W has been No TWDR action or
X
0
1
received;
ACK has been returned _{No TWDR action}
X
0
1
$68
Arbitration lost in
No TWDR action or
X
0
1
SLA+R/W as Master;
own SLA+W has been
received;
No TWDR action
X
0
1
ACK has been returned
$70
General call address
No TWDR action or
X
0
1
has been received;
ACK has been returned _{No TWDR action}
X
0
1
$78
Arbitration lost in
No TWDR action or
X
0
1
SLA+R/W as Master;
General call address
has been received;
No TWDR action
X
0
1
ACK has been returned
$80
Previously addressed
No TWDR action or
X
0
1
with own SLA+W; data
has been received;
No TWDR action
ACK has been returned
X
0
1
$88
Previously addressed
Read data byte or
0
0
1
with own SLA+W; data
has been received;
Read data byte or
0
0
1
NOT ACK has been
returned
Read data byte or
1
0
1
Read data byte
1
0
1
TWEA
0
1
0
1
0
1
0
1
0
1
0
1
0
1
Next Action Taken by 2-wire
Serial Hardware
Data byte will be received and NOT ACK
will be returned
Data byte will be received and ACK will be
returned
Data byte will be received and NOT ACK
will be returned
Data byte will be received and ACK will be
returned
Data byte will be received and NOT ACK
will be returned
Data byte will be received and ACK will be
returned
Data byte will be received and NOT ACK
will be returned
Data byte will be received and ACK will be
returned
Data byte will be received and NOT ACK
will be returned
Data byte will be received and ACK will be
returned
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 GC = “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 GC = “1”; a START condition
will be transmitted when the bus becomes
free
142 AT94K Series FPSLIC
Rev. 1138F–FPSLI–06/02