The use of watchdog timer for restoration of microprocessor systems with enhanced fault tolerance to influence of electrostatic discharges

Abstract

Microprocessor systems, which are designed for long-term continuous operation in a standalone mode, must provide a minimum downtime during their exploitation. The impact of electrostatic discharges on a microprocessor system can cause its damage. Damage to the system is the cause of its malfunction that can be either a self-resolving failure or a failure which is eliminated by minor operator intervention. This failure can lead to a hang of the microprocessor system which increases the system downtime and reduces the efficiency of its usage. According to the results of the study of the behavior of systems under failure both in laboratory conditions and directly at enterprises, a basic electrical circuit and an algorithm for the operation of an external watchdog timer relative to the microprocessor have been developed which allows to restore the microprocessor of autonomous systems after its exposure to electrostatic discharges that do not exceed the destruction threshold by restarting it by power in the automatic mode. The hardware and software implementation of the developed method for increasing the fault tolerance to the effects of electrostatic discharges is presented and put into operation. Efficiency of this technical solution is confirmed by the results of the exploitation during a few years of several hundred microprocessor systems at various Ukrainian enterprises for military, industrial, residential and municipal purposes. The solution of this problem had been performed by the author of this article at the level of absolute world novelty what is confirmed by a patent.