采用CPU Timer0定时，在定时器中断服务程序中记录中断的次数。-The number of CPU Timer0 regularly recorded in the timer interrupt service routine interrupt.

采用CPU Timer0产生定时周期50ms，输出锯齿波使能看门狗，在主函数中刷新计数器-The CPU Timer0 timing cycle of 50ms, the output sawtooth enable the watchdog refresh counter in the main function