SPI stands for Serial Peripheral Interface. It is a synchronous serial communication protocol widely used in electronic devices for data exchange between microcontrollers and peripheral devices like sensors, displays, memory modules, and other integrated circuits.
The SPI interface typically consists of four wires: a clock signal (SCLK) that synchronizes the data transfer, a data output from the master device (MOSI) to the slave device, a data input from the slave device (MISO) to the master device, and a chip select (CS) line that enables communication with a specific slave device.
The SPI protocol operates in a master-slave configuration, where a single master device initiates and controls communications with one or more slave devices. Data is transferred in full-duplex mode, meaning that each device can send and receive data simultaneously.
To transmit data, the master device sends a clock signal while shifting out data bits on the MOSI line. The slave device synchronizes with the clock and reads the data on the MISO line. Conversely, to receive data, the master device sends clock pulses while reading data from the MISO line sent by the slave device.
SPI supports various data formats like 8-bit, 16-bit, and even custom bit lengths. It also allows for different clock rates and multiple slave devices with unique chip select lines on the same bus. Since SPI is a widely adopted standard, it can be found in many electronic systems and is especially prevalent in embedded systems and microcontrollers.
