/看门狗定时器（WDT）是在每一个硬件定时器复位这使

/ /将一个可编程的后超时间隔。当WDT超时，它

/ /将强制器件复位。为了防止复位，WDT必须重新启动

/ /由应用软件之前，溢出。如果系统遇到

/ /软件或硬件故障无法重启软件

-// The Watchdog Timer (WDT) is a hardware timer enabled on every reset that

// will timeout after a programmable interval.　When the WDT times out, it

// will force a device reset. To prevent the reset, the WDT must be restarted

// by application software before it overflows. If the system experiences a

// software or hardware malfunction preventing the software from restarting