mcu与cpld之间spi接口程序，mcu为master，cpld用verilog写成slave模块,mcu with spi interface program between the CPLD, mcu for the master, cpld written using Verilog slave module

spi slave的verilog程序，有测试平台testbench程序，实现fpga作为salve的功能(spi slave verilog program)