Implementation method of PWM data transmission in input mode

Abstract

The invention provides an implementation method of PWM data transmission in an input mode. According to the method, when a PWM is in the input mode, a CPU configures an input waveform to adopt an FIFO buffer mode in a control register; when the input waveform jumps, jump information and a corresponding zone bit thereof are stored into FIFO; when a storage value in the FIFO reaches a limit value, the CPU interrupts a PWM output waveform, and reads data in the FIFO; and after the CPU reads off the data in the FIFO, the PWM output waveform is started. The CPU does not need to frequently respond to the interruption, so that the data can be rapidly read; and the possibility of data loss is lowered.

Description

technical field [0001] The invention relates to a realization method of PWM transmitting data in an input mode. Background technique [0002] At present, in the input mode, the PWM will use the working clock to detect the jump of the external input waveform. When the external waveform jumps, the PWM will reflect the corresponding high-level time and low-level time to the register. (that is, the PWM records the time of the high and low levels of the external clock in the input mode, and the time information is recorded in this register through the PWM operation), and an interrupt is generated to notify the CPU to read the register. However, when the external input waveform changes rapidly, the traditional design method will cause the CPU to read the information of this register. This information may be overwritten by the subsequent waveform information, resulting in information loss. This data is the cycle of the waveform, the duration of the high and low levels and other re...

AI Technical Summary

Problems solved by technology

However, when the external input waveform changes rapidly, the traditional design method will cause the CPU to read the information of this register. This information may be overwritten by the subsequent waveform information, resulting in information loss.

This data is the cycle of the waveform, the duration of the high and low levels and other related information (that is, the CPU does not read the data fast enough, so that the data is lost)

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