The Serial Peripheral Interface (SPI) module is a synchronous serial interface useful for communicating with other peripheral or microcontroller devices. These peripheral devices may be Serial EEPROMs, shift registers, display drivers, A/D converters, etc.Block diagram of the SPI module is shown on picture. Depending on the variant, the dsPIC30F family offers one or two SPI modules on a single device. SPI1 and SPI2 are functionally identical. The SPI2 module is available in many of the higher pin count packages (64-pin and higher), while the SPI1 module is available on all devices.