36.6.3.6.2 Hardware Actions in Client Mode

Table 36-6. Interrupt Request Conditions for Valid SERCOM I²C Client Configurations
Direction	CTRLB. SMEN	CTRLC. DATA32B	LENGTH. LENEN	Condition
Host Write	0	0	0	INTFLAG.DRDY = 1 if Rx FIFO is full INTFLAG.RXFF = 1 if Rx FIFO threshold is reached or length transaction is completed
	0	1	0
	0	1	1
	1	0	0
	1	1	0
	1	1	1
Host Read	0	0	0	INTFLAG.DRDY = 1 if Tx FIFO is empty and SCL hold INTFLAG.TXFE = 1 if Tx FIFO is empty or Tx FIFO threshold is reached
	0	1	0
	0	1	1
	1	0	0
	1	1	0
	1	1	1

Table 36-7. Bus Actions for Valid SERCOM I²C Client Configurations
Direction	CTRLB. SMEN	CTRLC. DATA32B	LENGTH. LENEN	Actions
Host Write	0	0	0	Byte mode operation SCL stretched if RX FIFO is full
	0	1	0	32-bit mode operation SCL stretched if RX FIFO is full ACK/NACK each 4th byte, depending on Acknowledge Action (CTRLB.ACKACT) ACK all other bytes
	0	1	1	32-bit mode operation with length control SCL stretched if RX FIFO is full ACK/NACK last byte of the frame, depending on Acknowledge Action (CTRLB.ACKACT) ACK all other bytes
	1	0	0	SCL stretched if RX FIFO is full ACK all bytes received
	1	1	0	32-bit mode operation SCL stretched if RX FIFO is full ACK/NACK each 4th byte, depending on Acknowledge Action (CTRLB.ACKACT) ACK all other bytes
	1	1	1	32-bit mode operation with length control SCL stretched if RX FIFO is full ACK/NACK last byte of the frame, depending on Acknowledge Action (CTRLB.ACKACT) ACK all other bytes
Host Read	0	0	0	SCL stretched if TX FIFO is empty
	0	1	0	SCL stretched if TX FIFO is empty
	0	1	1	SCL stretched if TX FIFO is empty and length transaction is not completed
	1	0	0	SCL stretched if TX FIFO is empty
	1	1	0	SCL stretched if TX FIFO is empty
	1	1	1	SCL stretched if TX FIFO is empty and length transaction is not completed