Serial peripheral interface (SPI) is a synchronous serial data protocol that enables the microprocessor and peripheral devices to communicate with each other. The SPI controller is an APB slave in the PolarFire SoC FPGA that provides a serial interface compliant with the Motorola SPI, Texas Instruments synchronous serial, and National Semiconductor MICROWIRE™ formats. In addition, SPI supports interfacing with large SPI Flash and EEPROM devices and a hardware-based slave protocol engine. PolarFire SoC FPGAs contain two identical SPI controllers SPI_0 and SPI_1 in the microprocessor subsystem.