Serial Peripheral Interface

Serial Peripheral Interface (SPI) is a de facto standard (with many variants) for synchronous serial communication, used primarily in embedded systems for short-distance wired communication between integrated circuits.

SPI follows a master–slave architecture, where a device (variously called master, leader, controller, main...) orchestrates communication with one or more devices (variously called slave, follower, target, sub...) by driving the clock and chip select signals. As there is no formal standard, some manufacturers introduce devices with the ability to change their roles on the fly.