A circuit that uses serial port communication to control cpu reset

Abstract

The invention relates to the field of automatic control, and particularly discloses a circuit for controlling CPU reset through serial port communication. The problems that existing CPU reset control is poor in initiative, and reset operation cannot be conducted under the condition that a CPU system program is deviated are solved. The circuit for controlling CPU reset through the serial port communication comprises a first resistor and a second resistor, the first resistor and the second resistor access an SCITXD of an upper computer in parallel, the other end of the first resistor accesses a first pin of a double diode, the other end of the second resistor accesses a third pin of the double diode and the base electrode of a PNP triode, a second pin of the double diode and the emitting electrode of the PNP triode are connected and access a reset pin of a CPU, the base electrode of the PNP triode is connected with a first capacitor, the other end of the capacitor is connected with the collector of the PNP triode and then grounded.

Description

technical field [0001] The invention relates to the field of automatic control, in particular to a circuit for controlling CPU reset by serial port communication. Background technique [0002] The serial port is a very mature low-speed communication interface. In today's high-density high-speed systems, it is still widely used in many intelligent and manageable chips and cannot be replaced. Existing intelligent electronic products are generally controlled by CPU, and reset operation is required when the CPU is powered on and when the program runs out of order. The quality of CPU reset directly affects the stability and reliability of electronic products. In the prior art, commonly used reset circuits include a simple resistance-capacitance circuit, button reset, built-in watchdog reset circuit, reset IC, and the like. [0003] Simple resistance-capacitance reset circuit can only perform power-on reset passively, and cannot perform reset operation when the CPU system program...

AI Technical Summary

Problems solved by technology

[0003] Simple resistance-capacitance reset circuit can only perform power-on reset passively, and cannot perform reset operation when the CPU system program deviates; button reset is a reset through manual intervention, but it cannot meet the needs of automatic control; gatekeeper Dog reset circuit, realizing CPU reset control not only occupies CPU resources, increases load, but also affects the efficiency of CPU processing other tasks; dedicated reset IC is too expensive

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