看门狗应用.本程序系统启动时,LED1点亮,正常运行时,LED1熄灭,LED2开始闪烁程序设置看门狗溢出时间为:1.9s,定时器必须在此时间内复位看门狗(喂狗),否则会引起系统复位,LED1再次点亮后熄灭,LED2重新开始持续闪烁.-Watchdog application of this procedure when the system starts, LED1 lights up during normal operation, LED1 off, LED2 starts flashing setup Watchdog overflow time: 1.9s, within this time, the timer must reset the watchdog (feed dog), otherwise it will cause a system reset, LED1 lit off again, LED2 blinks start.