WatchDog失效机理与对策研究

在工业控制领域,程序的失效恢复问题是一重要而棘手的问题,一般采用方法是在程序正常运行必然要经过的地方安插WatchDog复位指令,当遇到程序死锁、跑飞等程序失效问题时,启动WatchDog,使程序恢复正常。但WatchDog并非绝对安全,常常失去有效性,使系统瘫痪。本文对WatchDog失效机理与对策做了一些探讨,并结合工程应用给出了几款有效的硬件WatchDog电路。

Research on failure mechanism and countermeasure of WatchDog

In industry control domain, the question about program failure and recovery is one important and thorny question. The generally method is to place WatchDog replacement instruction in some normal inevitably program operating places. When program runs in deadbolt lock or run away, WatchDog starts to work and make program restore to work normally. But WatchDog is not absolutely safe, which loses frequently the validity and makes the system paralysis. The failure mechanism and countermeasures about WatchDog are discussed and some effective WatchDog hardware circuits are given in the paper.