C8051F340/1/2/3/4/5/6/7
Table 17.4. SMBus Status Decoding
Values
Written
Values Read
Current SMbus State
Typical Response Options
Load slave address + R/W
into SMB0DAT.
1110
1100
0
0
0
0
X A master START was generated.
0
0
X
Set STA to restart transfer.
Abort transfer.
1
0
0
1
X
X
A master data or address byte
was transmitted; NACK received.
0
Load next data byte into
SMB0DAT.
0
0
1
1
0
1
1
0
X
X
X
X
End transfer with STOP.
End transfer with STOP and
start another transfer.
A master data or address byte
was transmitted; ACK received.
0
0
1
Send repeated START.
Switch to Master Receiver
Mode (clear SI without writ-
ing new data to SMB0DAT).
0
0
X
Acknowledge received byte;
Read SMB0DAT.
0
0
0
1
1
0
Send NACK to indicate last
byte, and send STOP.
Send NACK to indicate last
byte, and send STOP fol-
lowed by START.
1
1
1
1
0
0
0
1
0
Send ACK followed by
repeated START.
A master data byte was received;
ACK requested.
Send NACK to indicate last
byte, and send repeated
START.
1000
1
0
X
Send ACK and switch to
Master Transmitter Mode
(write to SMB0DAT before
clearing SI).
0
0
0
0
1
0
Send NACK and switch to
Master Transmitter Mode
(write to SMB0DAT before
clearing SI).
Rev. 1.0
213
SILICON [ SILICON ]
