数字频率计 采用Verilog语言编写，分为8个模块，分别是计数器，门控，分频，寄存器，多路选择，动态位选择，BCD译码模块-Digital frequency meter using Verilog language, divided into eight modules, namely, the counter, gated, frequency, register, multiplexer, Dynamic Choice, BCD decoding module