单片机自恢复的实用方法

AUTOMATIC RECOVERY OF SINGLECHIP MICROCOMPUTERS

总结了常用单片机自恢复方法，分析了采用常用的自恢复方法后有时仍死机的原因，尤其对包含复位“看门狗”＿指令的死循环，失控程序改变中断设置方式、关闭某些有用中断造成程序局部瘫痪，失控程序修改单片机专用寄存器内容，使它进入掉电或睡眠工作方式等问题作了探讨。最后提出了三种提高自恢复能力和解决实际问题的自恢复方法。其中相互监视系统具有简单、可靠，软件和ＣＰＵ时间开销少的优点．保证在单故障的情况下，不会出现系统风机或局部瘫痪。

This paper summaizes general automatic recovery methods of single--chip microcomputers, then analyzes the reasons that the system--down is still inevitable even these methods having used. Especially, the peper discusses a series of questions such as: the dead--loop including the instruction of a watchdog reset, the uncontrollable programmes that change the set method of interrupts or close some useful interrupts causing the programme partly paralyzed; the uncontrollable programmes which change the contents of the rlglsters and cause the single--chip mlcrocomputers enter the state of battery--fail or sleeping. At last, three methods for the automatic recovery are presented, which can solve practical problems and increase the ability of the automatic recovery. Especially, the cross monitoring system has several advantages: simplicity, reliability, easier implementation and a little overhead and ensure against the state of system--down or the system partly paralysised when the single--chip computers faults occur.