本设计的内容是使用89C51RC单片机最小系统设计频率计系统，系统以单片机为主控单元，主要用于对方波频率的测量。 -The content of this design is the use of the smallest single-chip system design 89C51RC frequency of the system, a single chip for the main control unit, mainly for the other side of the mea