Справочник Пользователя для Silicon Laboratories C8051F342
Rev. 0.5
203
C8051F340/1/2/3/4/5/6/7
Table 17.3. Sources for Hardware Changes to SMB0CN
Bit
Set by Hardware When:
Cleared by Hardware When:
MASTER
•
A START is generated.
•
A STOP is generated.
•
Arbitration is lost.
TXMODE
•
START is generated.
•
SMB0DAT is written before the start of an
SMBus frame.
•
A START is detected.
•
Arbitration is lost.
•
SMB0DAT is not written before the
start of an SMBus frame.
STA
•
A START followed by an address byte is
received.
•
Must be cleared by software.
STO
•
A STOP is detected while addressed as a
slave.
•
Arbitration is lost due to a detected STOP.
•
A pending STOP is generated.
ACKRQ
•
A byte has been received and an ACK
response value is needed.
•
After each ACK cycle.
ARBLOST
•
A repeated START is detected as a MASTER
when STA is low (unwanted repeated START).
•
SCL is sensed low while attempting to gener-
ate a STOP or repeated START condition.
•
SDA is sensed low while transmitting a ‘1’
(excluding ACK bits).
•
Each time SI is cleared.
ACK
•
The incoming ACK value is low (ACKNOWL-
EDGE).
•
The incoming ACK value is high (NOT
ACKNOWLEDGE).
SI
•
A START has been generated.
•
Lost arbitration.
•
A byte has been transmitted and an ACK/
NACK received.
•
A byte has been received.
•
A START or repeated START followed by a
slave address + R/W has been received.
•
A STOP has been received.
•
Must be cleared by software.