18.4.3 SMB0CN0: SMBus 0 Control
Bit
7
6
5
4
3
2
1
0
Name
MASTER
TXMODE
STA
STO
ACKRQ
ARBLOST
ACK
SI
Access
R
R
RW
RW
R
R
RW
RW
Reset
0
0
0
0
0
0
0
0
SFR Page = 0x0, 0x20; SFR Address: 0xC0 (bit-addressable)
Bit
Name
Reset
Access Description
7
MASTER
0
R
SMBus Master/Slave Indicator.
This read-only bit indicates when the SMBus is operating as a master.
Value
Name
Description
0
SLAVE
SMBus operating in slave mode.
1
MASTER
SMBus operating in master mode.
6
TXMODE
0
R
SMBus Transmit Mode Indicator.
This read-only bit indicates when the SMBus is operating as a transmitter.
Value
Name
Description
0
RECEIVER
SMBus in Receiver Mode.
1
TRANSMITTER
SMBus in Transmitter Mode.
5
STA
0
RW
SMBus Start Flag.
When reading STA, a '1' indicates that a start or repeated start condition was detected on the bus.
Writing a '1' to the STA bit initiates a start or repeated start on the bus.
4
STO
0
RW
SMBus Stop Flag.
When reading STO, a '1' indicates that a stop condition was detected on the bus (in slave mode) or is pending (in master
mode).
When acting as a master, writing a '1' to the STO bit initiates a stop condition on the bus. This bit is cleared by hardware.
3
ACKRQ
0
R
SMBus Acknowledge Request.
Value
Name
Description
0
NOT_SET
No ACK requested.
1
REQUESTED
ACK requested.
2
ARBLOST
0
R
SMBus Arbitration Lost Indicator.
Value
Name
Description
0
NOT_SET
No arbitration error.
1
ERROR
Arbitration error occurred.
EFM8UB3 Reference Manual
System Management Bus / I2C (SMB0)
silabs.com
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