Microchip® Advanced Software Framework

SERCOM USART MUX Settings

The following lists the possible internal SERCOM module pad function assignments, for the four SERCOM pads when in USART mode.

Note that this is in addition to the physical GPIO pin MUX of the device, and can be used in conjunction to optimize the serial data pin-out.

When TX and RX are connected to the same pin, the USART will operate in half-duplex mode if both one transmitter and several receivers are enabled.

Note
When RX and XCK are connected to the same pin, the receiver must not be enabled if the USART is configured to use an external clock.
MUX/Pad PAD 0 PAD 1 PAD 2 PAD 3
RX_0_TX_0_XCK_1 TX / RX XCK - -
RX_0_TX_2_XCK_3 RX - TX XCK
RX_1_TX_0_XCK_1 TX RX / XCK - -
RX_1_TX_2_XCK_3 - RX TX XCK
RX_2_TX_0_XCK_1 TX XCK RX -
RX_2_TX_2_XCK_3 - - TX / RX XCK
RX_3_TX_0_XCK_1 TX XCK - RX
RX_3_TX_2_XCK_3 - - TX RX / XCK