Specifications

124
3706C–MICRO–2/11
AT89LP3240/6440
.
Table 18-9. Status Codes for Slave Transmitter Mode
Status
Code
(TWSR)
Status of the Two-wire
Serial Bus and Two-wire
Serial Interface Hardware
Application Software Response
Next Action Taken by TWI HardwareTo/from TWDR
To TWCR
STA STO TWIF AA
A8h
Own SLA+R has been
received; ACK has been
returned
Load data byte X 0 1 0
Last data byte will be transmitted and NOT
ACK should be received
Load data byte X 0 1 1
Data byte will be transmitted and ACK should
be received
B0h
Arbitration lost in S
LA+R/W
as master; own SLA+R has
been received; ACK has
been returned
Load data byte X 0 1 0
Last data byte will be transmitted and NOT
ACK should be received
Load data byte X 0 1 1
Data byte will be transmitted and ACK should
be received
B8h
Data byte in TWDR has
been transmitted; ACK has
b
een received
Load data byte X 0 1 0
Last data byte will be transmitted and NOT
ACK should be received
Load data byte X 0 1 1
Data byte will be transmitted and ACK should
be received
C0h
Data byte in TWDR has
been transmitted; NOT ACK
has been received
No action 0 0 1 0
Switched to the not addressed Slave mode; no
recognition of own SLA or GCA
No action 0 0 1 1
Switched to the not addressed Slave mode;
own SLA will be recognized; GCA will be
recognized if GC = “1”
No action 1 0 1 0
Switched to the not addressed Slave mode; no
recognition of own SLA or GCA; a STA RT
condition will be transmitted when the bus
becomes free
No action 1 0 1 1
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
C8h
Last data
byte in TWDR has
been transmitted (AA = “0”);
ACK has been received
No action 0 0 1 0
Switched to the not addressed Slave mode; no
recognition of own SLA or GCA
No action 0 0 1 1
Switched to the not addressed Slave mode;
own SLA will be recognized; GCA will be
recognized if GC = “1”
No action 1 0 1 0
Switched to the not addressed Slave mode; no
recognition of own SLA or GCA; a STA RT
condition will be transmitted when the bus
becomes free
No action 1 0 1 1
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