Method and system for capturing analog signal cycles

Abstract

The invention discloses a method for capturing analog signal cycles. The method includes the steps: scanning received analog signals and sampling signal values in real time; when the signal values exceed an upper threshold or are below a lower threshold, trigging an AWD (analog watch dog) to break off and recording the count value of a system clock when trigging the AWD to break off; when the AWD is triggered to break off due to the fact that the signal values exceed the upper threshold, setting the upper threshold to be the preset maximum upper threshold and setting the lower threshold to be the preset normal lower threshold; when the AWD is triggered to break off due to the fact that the signal values are lower than the lower threshold, setting the upper threshold to be the preset normal upper threshold, setting the lower threshold to be the preset minimum lower threshold, and returning to continue the steps before scanning and receiving analog signal cycles. The invention further discloses a system for capturing the analog signal cycles. By the aid of an AWD function of a single-chip microcontroller, the analog signal cycles can be captured, and accuracy and flexibility in capturing the analog signal cycles are improved.

Description

technical field [0001] The invention relates to the technical field of signal processing, in particular to a method and system for capturing the period of an analog signal. Background technique [0002] Most of the single-chip microcomputers launched by STMicroelectronics (abbreviated as ST) have AWD (Analog Watch Dog, analog watchdog) function, that is, the GPIO (General Purpose Input Output, general purpose input / output) port of the single-chip microcomputer has AWD function, AWD The function is to continuously detect the voltage value of the GPIO port of the microcontroller through the ADC (Analog-to-Digital Converter, analog / digital converter). The corresponding semaphore will be generated when the lower limit threshold value is determined, so as to realize the reset function of the single-chip microcomputer. [0003] At present, when analyzing various analog signals in the industry, the comparator is used to detect the voltage value of the GPIO port of the microcontrol...

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Problems solved by technology

However, in this scheme, the comparator can only compare a fixed value, which will cause missed detection, resulting in detection errors. At the same time, the use of comparator detection requires a peripheral hysteresis circuit to adjust the upper and lower thresholds, and the threshold adjustment is not enough. Flexible, and the cost is high, and the implementation method is also complicated

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