C8051T620/1/6/7 & C8051T320/1/2/3
212
Rev. 1.2
Slav
e T
ra
n
smitt
e
r
0100
0
0
0
A slave byte was transmitted;
NACK received.
No action required (expecting
STOP condition).
0
0
X
0001
0
0
1
A slave byte was transmitted;
ACK received.
Load SMB0DAT with next data
byte to transmit.
0
0
X
0100
0
1
X
A Slave byte was transmitted;
error detected.
No action required (expecting
Master to end transfer).
0
0
X
0001
0101
0
X
X
An illegal STOP or bus error
was detected while a Slave
Transmission was in progress.
Clear STO.
0
0
X
—
Slave
Re
ceive
r
0010
1
0
X
A slave a R/W was
received; ACK requested.
If Write, Acknowledge received
address
0
0
1
0000
If Read, Load SMB0DAT with
data byte; ACK received address
0
0
1
0100
NACK received address.
0
0
0
—
1
1
X
Lost arbitration as master;
slave a R/W received;
ACK requested.
If Write, Acknowledge received
address
0
0
1
0000
If Read, Load SMB0DAT with
data byte; ACK received address
0
0
1
0100
NACK received address.
0
0
0
—
Reschedule failed transfer;
NACK received address.
1
0
0
1110
0001
0
0
X
A STOP was detected while
addressed as a Slave Trans-
mitter or Slave Receiver.
Clear STO.
0
0
X
—
1
1
X
Lost arbitration while attempt-
ing a STOP.
No action required (transfer
complete/aborted).
0
0
0
—
0000
1
0
X
A slave byte was received;
ACK requested.
Acknowledge received byte;
Read SMB0DAT.
0
0
1
0000
NACK received byte.
0
0
0
—
Bus Error Condition
0010
0
1
X
Lost arbitration while attempt-
ing a repeated START.
Abort failed transfer.
0
0
X
—
Reschedule failed transfer.
1
0
X
1110
0001
0
1
X
Lost arbitration due to a
detected STOP.
Abort failed transfer.
0
0
X
—
Reschedule failed transfer.
1
0
X
1110
0000
1
1
X
Lost arbitration while transmit-
ting a data byte as master.
Abort failed transfer.
0
0
0
—
Reschedule failed transfer.
1
0
0
1110
Table 24.5. SMBus Status Decoding With Hardware ACK Generation Disabled (EHACK = 0)
(Continued)
Mode
Values Read
Current SMbus State
Typical Response Options
Values to
Write
Ne
xt
S
ta
tus
V
e
ct
or Expe
cte
d
St
a
tu
s
V
ect
or
ACK
RQ
ARBLOST
ACK
ST
A
ST
O
ACK