Serial Peripheral Interface

The Serial Peripheral Interface (SPI) is a synchronous serial communication interface specification. It is used for short-distance communication, primarily in embedded systems. SPI devices communicate in full duplex mode using a master-slave architecture.
The master (controller) device originates the for reading and writing. The SPI may be accurately described as a synchronous serial interface. But it is different from the Synchronous Serial Interface (SSI) protocol.
Developer.
The interface was developed by in the mid-1980s. Later it has become a "de facto" standard.