C8051T620/1/6/7 & C8051T320/1/2/3
202
Rev. 1.2
SFR Address = 0xC0; Bit-Addressable
SFR Definition 24.2. SMB0CN: SMBus Control
Bit
7
6
5
4
3
2
1
0
Name
MASTER
TXMODE
STA
STO
ACKRQ
ARBLOST
ACK
SI
Type
R
R
R/W
R/W
R
R
R/W
R/W
Reset
0
0
0
0
0
0
0
0
Bit
Name
Description
Read
Write
7
MASTER
SMBus Master/Slave
Indicator.
This read-only bit
indicates when the SMBus is
operating as a master.
0: SMBus operating in
slave mode.
1: SMBus operating in
master mode.
N/A
6
TXMODE
SMBus Transmit Mode
Indicator.
This read-only bit
indicates when the SMBus is
operating as a transmitter.
0: SMBus in Receiver
Mode.
1: SMBus in Transmitter
Mode.
N/A
5
STA
SMBus Start Flag.
0: No Start or repeated
Start detected.
1: Start or repeated Start
detected.
0: No Start generated.
1: When Configured as a
Master, initiates a START
or repeated START.
4
STO
SMBus Stop Flag.
0: No Stop condition
detected.
1: Stop condition detected
(if in Slave Mode) or pend-
ing (if in Master Mode).
0: No STOP condition is
transmitted.
1: When configured as a
Master, causes a STOP
condition to be transmit-
ted after the next ACK
cycle.
Cleared by Hardware.
3
ACKRQ
SMBus Acknowledge
Request.
0: No Ack requested
1: ACK requested
N/A
2
ARBLOST
SMBus Arbitration Lost
Indicator.
0: No arbitration error.
1: Arbitration Lost
N/A
1
ACK
SMBus Acknowledge.
0: NACK received.
1: ACK received.
0: Send NACK
1: Send ACK
0
SI
SMBus Interrupt Flag.
This bit is set by hardware
under the conditions listed in
Table 15.3. SI must be cleared
by software. While SI is set,
SCL is held low and the
SMBus is stalled.
0: No interrupt pending
1
:
Interrupt Pending
0: Clear interrupt, and initi-
ate next state machine
event.
1: Force interrupt.