The Serial Peripheral Interface (SPI) is one of the available modes in the Serial Communication Interface (SERCOM).

The SPI uses the SERCOM transmitter and receiver configured as shown in Block Diagram. Each side, host and client, depicts a separate SPI containing a Shift register, a transmit buffer and a two-level or four-level receive buffer. In addition, the SPI host uses the SERCOM baud-rate generator, while the SPI client can use the SERCOM address match logic. Labels in capital letters are synchronous to CLK_SERCOMx_APB and accessible by the CPU, while labels in lowercase letters are synchronous to the SCK clock.