将一个1Mhz的信号分频成100khz、10khz、1khz、100hz。实验要求每相差十倍频率就有脉冲输出，推荐采用十进制计数器对信号进行分频，即判断输入信号上升沿或下降沿的个数，每计满5个即让输出信号电平翻转，以此实现10分频。(Divide a 1Mhz signal into 100kHz, 10kHz, 1kHz and 100Hz. The experiment requires that every ten times the frequency of the difference is pulse output, it is recommended to use decimal counter to divide the signal, that is to judge the number of the rising or descending edge of the input signal, which is full 5, so that the output signal level is turned over, so as to achieve 10 frequency division.)