ST STM32F207 Series Reference Manual page 623

RM0033
Bit 14 TIMEOUT: Timeout or Tlow error
– When set in slave mode: slave resets the communication and lines are released by
– When set in master mode: Stop condition sent by hardware
– Cleared by software writing 0, or by hardware when PE=0.
Note: This functionality is available only in SMBus mode.
Bit 13 Reserved, must be kept at reset value
Bit 12 PECERR: PEC Error in reception
– Cleared by software writing 0, or by hardware when PE=0.
Note: When the received CRC is wrong, PECERR is not set in slave mode if the PEC control
Bit 11 OVR: Overrun/Underrun
– Set by hardware in slave mode when NOSTRETCH=1 and:
– In reception when a new byte is received (including ACK pulse) and the DR register has not
– In transmission when a new byte should be sent and the DR register has not been written
– Cleared by software writing 0, or by hardware when PE=0.
Note: If the DR write occurs very close to SCL rising edge, the sent data is unspecified and a
Bit 10 AF: Acknowledge failure
– Set by hardware when no acknowledge is returned.
– Cleared by software writing 0, or by hardware when PE=0.
Bit 9 ARLO: Arbitration lost (master mode)
– Cleared by software writing 0, or by hardware when PE=0.
Note: In SMBUS, the arbitration on the data in slave mode occurs only during the data phase,
0: No timeout error
1: SCL remained LOW for 25 ms (Timeout)
or
Master cumulative clock low extend time more than 10 ms (Tlow:mext)
or
Slave cumulative clock low extend time more than 25 ms (Tlow:sext)
hardware
0: no PEC error: receiver returns ACK after PEC reception (if ACK=1)
1: PEC error: receiver returns NACK after PEC reception (whatever ACK)
bit is not set before the end of the CRC reception. Nevertheless, reading the PEC value
determines whether the received CRC is right or wrong.
0: No overrun/underrun
1: Overrun or underrun
been read yet. New received byte is lost.
yet. The same byte is sent twice.
hold timing error occurs
0: No acknowledge failure
1: Acknowledge failure
0: No Arbitration Lost detected
1: Arbitration Lost detected
Set by hardware when the interface loses the arbitration of the bus to another master
After an ARLO event the interface switches back automatically to Slave mode (MSL=0).
or the acknowledge transmission (not on the address acknowledge).
Inter-integrated circuit (I2C) interface
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