分频器分频为2Hz后，使计数时间变为0.5秒一个，将此时的频率传给计数器，计数器计数的变化时间就变为0.5秒一变然后再用数码管显示出数字的变化，即可得到一个从0~9变化的计时器。
文件名为随便起的项目名称，使用时如果更改需要和代码中的实体名等一起更改(Frequency divider for 2Hz, the counting time is 0.5 seconds a, the frequency to change the time counter counter becomes 0.5 seconds for a variable and then use the digital display changes, you can get a change from the 0~9 timer.
The file name is the name of the item that you want to change when used, and the changes need to be changed together with the entity name in the code)