c8051t617 Silicon Laboratories, c8051t617 Datasheet - Page 147

• Manufacturer Part Number: c8051t617
• Description: Mixed Signal Byte-programmable Eprom Mcu
• Manufacturer: Silicon Laboratories

15.6. SMBus Status Decoding
The current SMBus status can be easily decoded using the SMB0CN register. In the table below, STATUS
VECTOR refers to the four upper bits of SMB0CN: MASTER, TXMODE, STA, and STO. Note that the
shown response options are only the typical responses; application-specific procedures are allowed as
long as they conform to the SMBus specification. Highlighted responses are allowed but do not conform to
the SMBus specification.
1100
1000
1110
Values Read
0
0
0
1
0
0
0
0
X
X
0
1
Current SMbus State
A master START was
generated.
A master data or address byte
was transmitted; NACK
received.
A master data or address byte
was transmitted; ACK
received.
A master data byte was
received; ACK requested.
Table 15.4. SMBus Status Decoding
Rev. 0.3
C8051T610/1/2/3/4/5/6/7
Typical Response Options
Load slave address + R/W into
SMB0DAT.
Set STA to restart transfer.
Abort transfer.
Load next data byte into
SMB0DAT.
End transfer with STOP.
End transfer with STOP and start
another transfer.
Send repeated START.
Switch to Master Receiver Mode
(clear SI without writing new data
to SMB0DAT).
Acknowledge received byte; Read
SMB0DAT.
Send NACK to indicate last byte,
and send STOP.
Send NACK to indicate last byte,
and send STOP followed by
START.
Send ACK followed by repeated
START.
Send NACK to indicate last byte,
and send repeated START.
Send ACK and switch to Master
Transmitter Mode (write to
SMB0DAT before clearing SI).
Send NACK and switch to Master
Transmitter Mode (write to
SMB0DAT before clearing SI).
0
1
0
0
0
1
1
0
0
0
1
1
1
0
0
Written
Values
0
0
1
0
1
1
0
0
0
1
1
0
0
0
0
147
X
X
X
X
X
X
X
X
1
0
0
1
0
1
0