SPI
What is SPI?
A type of synchronous serial communication that transmits data synchronized with the clock, SPI (Serial Peripheral Interface) is commonly used for data communication with EEPROMs and sensors.
SPI communication operates using four signal lines: clock (SCLK), data input (SIN), data output (SOUT), and chip select (CS).
When communicating, roles are divided into master and slave, where the master generates the clock signal, with data exchange synchronized to the clock.
A single master can connect to multiple slaves, but in such cases, each slave requires a dedicated CS signal line to communicate with the master.
The connections between master and slaves are as follows.
Overview of SPI Communication
The master generates the clock signal and sends data in sync with it. The slave receives data accordingly.
Even when the slave sends data, the master continues to generate the clock signal. The slave transmits data in sync with the clock, while the master receives it.
During communication, the master provides the clock signal, and allowing both the master and slave to transmit and receive data simultaneously.
SPI enables simultaneous data transmission and reception by shifting bits through a shift register.
The transmitting side outputs data from the most significant bit (MSB) via SOUT, while the receiving device captures data through SIN, storing it in the least significant bit (LSB) of the shift register. Transfer is complete once all bits are shifted through the register.
This mechanism ensures continuous, efficient data exchange between the master and slave.
