In short, in this communication protocol, devices exchange data in master/slave mode. This line is used to send data from the slave to the Master.
But in this article, We will see a general 4 wire interface. SPI interface consists of either three or four signals. The Block diagram below shows interfacing with one Master and one Slave. Both Master and Slave can exchange data with each other on the rising and falling edge of the clock signal. It is Full duplex synchronous communication. Both master and slave can exchange data with each other.Data can not be transferred without a clock signal.The only master device can control the clock and provide a clock signal to all slave devices.The clock signal controls when data is to be sent to the slave and when it should be ready to read.Unlike UART communication which is asynchronous.The synchronous interface means it requires a clock signal to transfer and receive data and the clock signal is synchronized between both master and slave.
Q LAB MASTER SLAVE CONTROL SERIAL
It is a serial and synchronous interface.Why SPI communication is used? SPI Communication Introduction.Different Configuration Modes of SPI Bus.