Crystal oscillator clock failure detection method

Abstract

The invention discloses a crystal oscillator clock failure detection method. The method comprises the following steps: a clock shaping module shapes a sine wave of a crystal oscillator clock generated by an external crystal oscillator into a square wave; the crystal oscillator frequency detection module detects whether the frequency of the crystal oscillator clock is within a preset range or not, and if not, an abnormal signal is generated; and after the abnormal signal is received, the clock safety management module switches a working clock of the chip system from a crystal oscillator clock to an internal RC clock. According to the crystal oscillator clock failure detection method, whether the external crystal oscillator stops oscillation can be rapidly and accurately detected, whether the frequency of the crystal oscillator clock is too fast or too slow can be detected, and when it is detected that the crystal oscillator clock is abnormal, the working clock of the chip system is switched into the internal RC clock in time, so that disordered operation of the chip system is avoided.

Description

technical field [0001] The invention relates to the technical field of crystal oscillator detection, in particular to a crystal oscillator clock failure detection method. Background technique [0002] With the development of chip technology and the increasingly higher requirements for chip performance in the market, it is necessary to have a higher guarantee for clock security during chip design, so that in actual application of the chip, it is possible to avoid external components ( Crystal oscillator) is disturbed by environmental factors and produces abnormalities, which leads to internal operation disorder of the chip. [0003] The existing solution is to use the crystal oscillator clock to sample the width of the pulse signal generated by the internal low-frequency clock, and then check whether the sampled value is within the range at the edge of the pulse, so as to determine whether the crystal oscillator stops oscillating. This method requires the frequency of the cr...

AI Technical Summary

Problems solved by technology

This method requires the frequency of the crystal oscillator to be higher than the frequency of the internal low-frequency signal, and the lower the frequency of the crystal oscillator, the speed at which the failure of the crystal oscillator is detected will decrease exponentially; At the time of failure, the chip is already in disorder

In addition, the existing technology usually only detects the situation where the crystal oscillator stops vibrating, but does not detect the situation where the frequency of the crystal oscillator is too fast or too slow due to the influence of external environmental factors. In fact, these situations may also cause the entire chip system to run go wrong

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