我这边DM8168上的看门狗超时后板子会复位重启，但量引脚WD_OUT却始终无信号。按照DM8168手册上所描述的，应该会产生低电平到PRCM模块和WD_OUT引脚，我既然已经成功复位那应该表明产生了低电平到PRCM，可WD_OUT怎么就没有呢？求助！
22.2.5 Overflow/Reset Generation
When the watchdog timer counter register (WDT_WCRR) overflows, an active-low reset pulse is
generated to the PRCM module. This RESET pulse causes the PRCM module to generate global WARM
reset of the device. It is also driven out of the device through the WD_OUT pin.
