2.5.8.2 Serial Peripheral Interface

The SPI controller is compliant with the Motorola SPI, Texas Instruments synchronous serial, and National Semiconductor MICROWIRE™ formats. In addition, the SPI supports interfacing to large SPI flash and EEPROM devices by way of the Client protocol engine. The SPI controller supports both Host and Client modes of operations.

The SPI controller embeds two 4 × 32 (depth × width) FIFOs for receive (RX) and transmit (TX). These FIFOs are accessible through RX data and TX data registers. Writing to the TX data register causes the data to be written to the transmit FIFO. This is emptied by the transmit logic. Similarly, reading from the RX data register causes data to be read from the receive FIFO.