The inter-integrated circuit ( I2C) interface is one of the available modes in the serial communication interface (SERCOM).

The I2C interface uses the SERCOM transmitter and receiver configured as shown in Figure 1. Labels in capital letters are registers accessible by the CPU, while lowercase labels are internal to the SERCOM.

A SERCOM instance can be configured to be either an I2C host or an I2C client. Both host and client have an interface containing a shift register, a transmit buffer and a receive buffer. In addition, the I2C host uses the SERCOM baud-rate generator, while the I2C client uses the SERCOM address match logic.