xilinx FPGA 实现spi通过74HC595扩展IO口源码程序-xilinx FPGA achieved through 74HC595 IO expansion port spi-source programs

基于xilinx FPGA 的SPI通过74HC595扩展IO数码动态显示-xilinx FPGA SPI 74HC595 extended by IO digital dynamic display

FPGA SPI部分代码，FPGA芯片采用xilinx sptan3e 可以实现FPGA的SPI的通信,用来控制外部74hc595-FPGA SPI part of the code, the FPGA chip using xilinx sptan3e can realize SPI communication, FPGA is used to control the external 74hc595 are needed