Datasheet
This bit is automatically cleared when the corresponding interrupt is also cleared.
Bit 6 – LOWTOUT SCL Low Time-out
This bit is set if an SCL low time-out occurs.
This bit is cleared automatically if responding to a new start condition with ACK or NACK (write 3 to
CTRLB.CMD) or when INTFLAG.AMATCH is cleared.
Writing a '0' to this bit has no effect.
Writing a '1' to this bit will clear the status.
Value Description
0
No SCL low time-out has occurred.
1
SCL low time-out has occurred.
Bit 4 – SR Repeated Start
When INTFLAG.AMATCH is raised due to an address match, SR indicates a repeated start or start
condition.
This flag is only valid while the INTFLAG.AMATCH flag is one.
Value Description
0
Start condition on last address match
1
Repeated start condition on last address match
Bit 3 – DIR Read / Write Direction
The Read/Write Direction (STATUS.DIR) bit stores the direction of the last address packet received from
a master.
Value Description
0
Master write operation is in progress.
1
Master read operation is in progress.
Bit 2 – RXNACK Received Not Acknowledge
This bit indicates whether the last data packet sent was acknowledged or not.
Value Description
0
Master responded with ACK.
1
Master responded with NACK.
Bit 1 – COLL Transmit Collision
If set, the I2C slave was not able to transmit a high data or NACK bit, the I2C slave will immediately
release the SDA and SCL lines and wait for the next packet addressed to it.
This flag is intended for the SMBus address resolution protocol (ARP). A detected collision in non-ARP
situations indicates that there has been a protocol violation, and should be treated as a bus error.
Note that this status will not trigger any interrupt, and should be checked by software to verify that the
data were sent correctly. This bit is cleared automatically if responding to an address match with an ACK
or a NACK (writing 0x3 to CTRLB.CMD), or INTFLAG.AMATCH is cleared.
Writing a '0' to this bit has no effect.
Writing a '1' to this bit will clear the status.
SAM D21 Family
SERCOM I2C – Inter-Integrated Circuit
© 2018 Microchip Technology Inc.
Datasheet Complete
DS40001882D-page 590