Introduction - If you have any usage issues, please Google them yourself
PCA (counter array) to achieve the timing function
说明：
explain：
利用单片机内部的PCA计数器实现16位的定时器功能。
Using MCU internal PCA counter to achieve the 16 bit timer function.
操作：
Operation:
将拨码开关S10的LED端拨到ON端。
Set the LED of the dial switch ON to the S10.
其他拨码开关都处于关闭状态，也就是不拨到ON端。
Other dial switches are in the closed state, that is, do not dial to the ON side.
可参考数据手册中关于PCA模块的详细说明
A detailed description of the PCA module in the reference data sheet