A Configurable SPI Interface Based on APB Bus

A configurable SPI interface based on APB bus is proposed in this paper. The SPI interface transmission information is configured through APB bus, which can realize the master-slave mode switching, 4 kinds of clock transmission mode switching and MSB/LSB communication mode switching. Meanwhile the transmission rate can be selected and the transmission length can be variable from 1 to 32 bits. Based on the SPI transmission protocol, the proposed design uses a finite state machine method to control the transmission timing of the SPI interface. The design was verified through RTL simulation and FPGA verification. The verification results show that the functional of SPI interface is correct and the data transmission is stable.