C8051F340/1/2/3/4/5/6/7

Table 17.4. SMBus Status Decoding

 

Values Read

 

 

 

 

Values

 

 

 

 

 

Written

Mode

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Status Vector

ACKRQ

ARBLOST

 

ACK

Current SMbus State

Typical Response Options

STA

 

STo

ACK

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1110

0

0

 

X

A master START was generated.

Load slave address + R/W

0

 

0

X

 

 

 

 

 

 

 

into SMB0DAT.

 

 

 

 

 

 

0

0

 

0

A master data or address byte

Set STA to restart transfer.

1

 

0

X

 

 

 

was transmitted; NACK received.

 

 

 

 

 

Transmitter

 

 

Abort transfer.

0

 

1

X

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Load next data byte into

0

 

0

X

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

SMB0DAT.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1100

 

 

 

 

 

End transfer with STOP.

0

 

1

X

Master

 

 

 

 

 

 

 

 

 

 

0

0

 

1

A master data or address byte

End transfer with STOP and

1

 

1

X

 

 

 

 

 

start another transfer.

 

 

 

was transmitted; ACK received.

 

 

 

 

 

 

 

 

 

Send repeated START.

1

 

0

X

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Switch to Master Receiver

 

 

 

 

 

 

 

 

 

 

 

Mode (clear SI without writ-

0

 

0

X

 

 

 

 

 

 

 

ing new data to SMB0DAT).

 

 

 

 

 

 

 

 

 

 

 

Acknowledge received byte;

0

 

0

1

 

 

 

 

 

 

 

Read SMB0DAT.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Send NACK to indicate last

0

 

1

0

 

 

 

 

 

 

 

byte, and send STOP.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Send NACK to indicate last

 

 

 

 

 

 

 

 

 

 

 

byte, and send STOP fol-

1

 

1

0

 

 

 

 

 

 

 

lowed by START.

 

 

 

 

Receiver

1000

1

0

 

X

ACK requested.

 

 

 

 

 

 

Send ACK followed by

1

 

0

1

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

repeated START.

 

 

 

 

 

 

 

A master data byte was received;

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Send NACK to indicate last

1

 

0

0

Master

 

 

 

 

 

 

byte, and send repeated

 

 

 

 

 

 

 

START.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Send ACK and switch to

 

 

 

 

 

 

 

 

 

 

 

Master Transmitter Mode

0

 

0

1

 

 

 

 

 

 

 

(write to SMB0DAT before

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

clearing SI).

 

 

 

 

 

 

 

 

 

 

 

Send NACK and switch to

 

 

 

 

 

 

 

 

 

 

 

Master Transmitter Mode

0

 

0

0

 

 

 

 

 

 

 

(write to SMB0DAT before

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

clearing SI).

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Rev. 0.5

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Image 209
Silicon Laboratories C8051F346, C8051F347, C8051F341 Values Read, Current SMbus State Typical Response Options, Start