Hardware watchdog and application circuit thereof

Abstract

The invention provides a hardware watchdog and an application circuit thereof. Message sending and receiving between a control chip and a monitoring chip are achieved by a communication interface circuit; a dog feeding request message is periodically sent to the control chip through the monitoring chip to require the control chip to reply a dog feeding operation message within a preset starting and ending time, if not, a reset signal is output; a low power consumption mode acknowledgment message is sent after a low power consumption mode request message sent by the control chip is received, and the sending of the dog feeding request message is paused within a first regulated time period; a reset circuit receives the reset signal and generates and outputs a reset control signal to the control chip, to control the control chip to reset. The hardware watchdog provided by the invention is a circuit independent from the control chip, and the reliability is higher than that of a software watchdog in the prior art; meanwhile, the low power consumption mode is achieved through the communication interface circuit to achieve low power consumption, and the energy saving property of the system is improved compared with a traditional hardware watchdog.

Description

technical field [0001] The invention relates to the technical field of electronic circuits, in particular to a hardware watchdog and an application circuit thereof. Background technique [0002] The watchdog is a functional unit used to monitor the operating state of the control chip (microcontroller MCU or microprocessor MPU) in the circuit, and can reset the control chip when there is a problem in the circuit and the control chip enters an endless loop state , to prevent further errors. [0003] Watchdogs in the prior art are classified into software watchdogs and hardware watchdogs. [0004] The software watchdog is usually a watchdog module integrated in the control chip, which itself is controlled by software and has a strong dependence on software reliability. [0005] The hardware watchdog is usually a relatively independent reset function circuit. Since the overflow time of the traditional hardware watchdog is generally not adjustable or can only be adjusted within...

AI Technical Summary

Problems solved by technology

[0006] In view of this, the present invention provides a hardware watchdog and its application circuit to solve the problems of low reliability of the software watchdog in the prior art and low energy saving of the system due to the working mode of the hardware watchdog

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