vhdl和c编写，fpga结合单片机完成测频计的功能，fpga主要完成频率的测量并把数据发送给单片机，单片机控制12864液晶完成显示-vhdl and c preparation, fpga of the single chip to complete the function of frequency meter, fpga major to complete the measurement frequency and the data sent to the MCU, MCU contro