What is SPI (Serial Peripheral Interface) ?

- Sep 15, 2019-

SPI (Serial Peripheral Interface) is a kind of synchronous serial peripheral interface, which enables MCU to communicate with various peripheral devices in serial mode to exchange information. 

SPI can be directly connected with various standard peripheral devices produced by various manufacturers, including FLASHRAM, network controller, LCD display driver, A/D converter and MCU. The interface generally uses four lines: serial clock line (SCLK), host input/slave output data line MISO, host output/slave input data line MOSI and low-level effective slave selection line NSS.

The full name of SPI interface is Serial Peripheral Interface, which means serial peripheral interface. Motorola first defined it on its MC68HCXX series processors. SPI interface is mainly used between EEPROM, FLASH, real-time clock, AD converter, digital signal processor and digital signal decoder.

SPI interface is a synchronous serial data transmission between CPU and peripheral low-speed devices. Under the shift pulse of the main device, the data is transmitted bit by bit. In thr front is high bit, the behind is low bit. For full duplex communication, the data transmission speed is generally faster than I2C bus, and the speed can reach several Mbps.