Method for realizing monitoring of level of signal

Abstract

The invention relates to a method for realizing the monitoring of the level of a signal, which comprises the following steps of: (1) setting the alarm threshold of an alarm counter according to the maximum sustainable time of the high level of the signal to be monitored and setting the interference threshold of an interference counter according to the maximum sustainable time of the interference of the signal to be monitored; (2) monitoring the level of the signal to be monitored; when the signal has a high level, enabling the alarm counter; (3) judging whether the count value of the alarm counter is equal to the alarm threshold or not; (4) judging whether the level of the signal to be monitored is changed into a low level or not when the alarm counter counts; (5) judging whether the count value of the interference counter is equal to the interference threshold or not; and (6) judging whether the level of the signal to be monitored is changed into the high level or not when the interference counter counts. The invention has better anti-jamming capability and simple circuit structure.

Description

technical field [0001] The invention relates to a method applied to a level monitoring module, in particular to a method for realizing monitoring signal levels. Background technique [0002] In digital systems, such a monitoring and alarm module is often required. This module monitors the high (low) level duration of a certain signal. If the high (low) level duration of the signal exceeds the alarm threshold, an alarm signal should be sent by the module. The alarm signal notifies other modules that the high (low) level duration of the monitored signal has exceeded the high (low) level alarm threshold. This type of circuit is relatively simple to implement. Take the implementation of the high-level monitoring and alarm module as an example. Only one alarm counter (counter enabled by high level) is needed to realize this function. The monitored signal is used as the enable signal of the counter. When the signal is high level, the alarm counter starts counting from zero. W...

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Problems solved by technology

[0003] However, in actual use, the monitored signal is often fluctuated by external interference. Taking the high-level detection and alarm module that monitors the duration of the high level as an example, the external interference will appear as a continuous high level of the monitored signal. Insert a short low level signal in the middle

If the interference signal lasts for a long time, it may cause the high-level counter to return to zero, thereby invalidating the high-level monitoring and alarm module

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