Hardware watchdog realization method based on MCU (Micro-programmed Control Unit)

Abstract

The invention discloses a hardware watchdog realization method based on an MCU (Micro-programmed Control Unit). The method comprises the steps of setting a corresponding MCU-based watchdog pin according to a needed watchdog function, distributing a time-out counter, an interrupt counter, time-out time and a resetting level time sequence; then receiving an external activation signal sent by a processor on monitoring equipment, beginning to count by the time-out counter; meanwhile judging whether the time-out counter performs a zero clearing operation according to the situation whether a periodic dog-feeding signal sent by the processor is received, and completing the monitoring for the running state of the processor. The method is good in openness, adjustable in control parameters, wide in application range, low in cost and simple in structure, improves the monitoring and resetting capabilities of an MCU-based hardware watchdog and reduces an area of an occupation circuit.

Description

technical field [0001] The invention relates to a hardware watchdog system, in particular to an MCU-based hardware watchdog implementation method, which belongs to the field of integrated circuits. Background technique [0002] When the embedded control system runs wrong or suffers from various interferences, the system will occasionally "crash", resulting in the failure of the entire system program to run. In order to prevent the occurrence of this kind of problem, it is necessary to add a watchdog (Watchdog) circuit outside the system processor during design for applications that require high system operation reliability. The role of the watchdog circuit is to restore the operation of the main program of the system when an error occurs in the system and enter a crash state, so as to ensure that the main program runs stably, reliably and continuously. [0003] The existing watchdog circuit mostly adopts the comprehensive design method of sub-module combination, and its d...

AI Technical Summary

Problems solved by technology

[0004] 1. The timing of the reset level output by the watchdog circuit cannot be selected, and cannot be adapted to the application occasions that require the coordination of the level timing to reset;

[0005] 2. The adjustable range of the timeout time of the watchdog circuit is a fixed T value or not adjustable at all, and the scope of application is narrow;

[0006] 3. The watchdog circuit is a comprehensive design of the reset signal generating circuit, the watchdog signal generating circuit and its auxiliary components. The components are used more, occupy a large circuit area, and are inconvenient to use in a small space.