1.1 UART I²C and Boot Pin Configurations

Table 1-1. Port Pin, USART and TWIHS Instance for UART and I²C
Protocol	Port Pin Configuration	USART and TWIHS Instance
UART	PC00 - TX - SERCOM0-PAD[0] PC01 - RX - SERCOM0-PAD[1]	SERCOM 0 (Can be accessed only in the Secure region)
I²C	PD01 - SDA - SERCOM1-PAD0 - External Pull-up required PD00 - SCL - SERCOM1-PAD1 - External Pull-up required	SERCOM 1 (Can be accessed only in the Secure region)
Boot pin	PA00 - GPIO - Input - Pull-up enabled	-

Table 1-2. UART and I²C Communication Configurations
Protocol	Communication Parameters
UART	115200 baud, 8-bit, Even parity, 1 Stop bit.
I²C	Up to 400 kHz speed. I²C client 7-bit address (`0x40`) - `1000-000x` (where x = 0 for write, 1 for read). Address is fixed and not programmable through any hardware setting.

1.1 UART I2C and Boot Pin Configurations