Microcomputer reset device and microcomputer reset method

摘要

A microcomputer reset apparatus including a counter for counting pulses of a pulse signal generated by a ring oscillator, and an edge detector driven by a clock signal of the microcomputer, for detecting an edge of each pulse of the pulse signal to produce a reset signal of the counter. The edge detector halts its edge detection when the clock signal is suspended so that the reset signal of the counter is not produced. Thus, the count value of the counter overflows without being reset, and the microcomputer is reset by the overflow signal. This can solve a problem of a conventional microcomputer reset apparatus in that when its microcomputer operates normally, the microcomputer must regularly supply its 8-bit timer (counter) with a reset pulse to prevent the 8-bit timer from overflowing and producing the reset signal of the microcomputer, and that this increases the processing load of the microcomputer.