Watchdog circuit system for automotive electronic control unit

Abstract

The invention relates to the technical field of electronic control units for automobiles, in particular to a watchdog circuit system for an electronic control unit of an automobile. The watchdog circuit system comprises a charging and discharging timing circuit and a reset circulation circuit. An input end of the charging and discharging timing circuit is connected with a WATCHDOG pin of a master chip by a capacitor C1 and is further connected with a +5V power source VDD by a resistor R1 and a jumper switch J1, an output end of the charging and discharging timing circuit is connected with a base electrode of a transistor Q3, a collector electrode of the transistor Q3 is grounded, an emitting electrode of the transistor Q3 is connected with a RESET pin of the master chip and an input end of the reset circulation circuit, and an output end of the reset circulation circuit is connected with the input end of the charging and discharging timing circuit; the duration of low-level signals received by the charging and discharging timing circuit is longer than the watchdog reset time, and in other words, high-level signals are outputted. The watchdog circuit system has the advantages that the system can be in various modes, has various functions and is provided with the charging and discharging timing circuit, so that a watchdog reset time adjustable function can be realized by the aid of hardware, and the circuit system is low in power consumption and cost and easy to implement.

Description

technical field [0001] The invention relates to the technical field of electronic control units for automobiles, in particular to a watchdog circuit system for electronic control units of automobiles. Background technique [0002] With the development of automobile technology, more and more electronic control unit components are used in automobiles, such as engine electronic control units, vehicle electronic control units, automatic transmission electronic control units, and motor control units used in new energy vehicles And battery management electronic control unit and so on. In order to meet the reliability design requirements of the system, a watchdog circuit is usually used on the main board of the electronic control unit to monitor the operating status of the main chip (single-chip microcomputer or DSP) in real time and generate a reset signal to reset the system to restore normal operation when software abnormalities are detected. , so as to avoid the software runni...

AI Technical Summary

Problems solved by technology

It has the following disadvantages: 1. In the application of automotive electronic control units, the main chip needs to enter the sleep mode to reduce system power consumption. The sleep time mostly exceeds the maximum reset time of the watchdog circuit. At this time, the watchdog circuit will mistakenly think that The program enters an infinite loop and resets; 2. In addition, due to the existence of the watchdog circuit, the main chip is easily affected by the reset signal during the programming process and fails

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