CN109831205A

CN109831205A - A kind of pulse counting method based on SoC

Info

Publication number: CN109831205A
Application number: CN201910039956.5A
Authority: CN
Inventors: 林忠侣; 林聪聪
Original assignee: Xiamen Xin De Information Technology Co Ltd
Current assignee: Xiamen Xin De Information Technology Co Ltd
Priority date: 2019-01-16
Filing date: 2019-01-16
Publication date: 2019-05-31

Abstract

The present invention relates to a kind of pulse counting methods based on SoC, an analog comparator, a timer, a direct memory access device to SoC is used only in it, resource consumption is considerably less, and only terminating to be measured preprocessor in signal just needs intervention to handle, and the time for occupying processor is very short.In entire pulse counting process, SOC does not increase external circuit, also the not maximum time width T of setting pulse signal, the more not intervention of software, is achieved that the purpose of accurate measurement number of pulses.

Description

A kind of pulse counting method based on SoC

Technical field

The present invention relates to step-by-step counting fields, and in particular to a kind of pulse counting method based on SoC.

Background technique

SoC is system on chip, refers to and is integrated with MCU, RAM, FLASH on a single die and a series of relative to MCU's Peripheral hardware, including Timer, DMA, COMP, ADC, DAC etc..

The pulse counting method of base SoC must know in advance that the maximum time width T of signal at present, prolong after signal appearance Time T reads counter afterwards.There are the following problems for this method:

1, since signal does not have beginning flag, can only judge according to there are several pulses, if system is interfered, it is easy to There is error starting tally function, causes measuring error；

2, the starting for judging signal according to several pulses that signal starts due to needs, needs system to have the response being exceedingly fast Speed, therefore the design difficulty of system and the investment of SoC resource are increased, or even software can only be allowed on certain SoC to intervene The execution of measurement affects the real-time of system；

3, when actual environment is run, the variation of temperature and the measured factors such as measurement range that exceed are likely to cause system Maximum time width T exceeds the delay time of system design, causes measuring error.

In view of this, the present inventor's deep design for problems existing for step-by-step counting field, and then develop The present invention.

Summary of the invention

In view of the above-mentioned problems, the purpose of the present invention is to provide a kind of pulse counting method based on SoC, without setting The maximum time width T of pulse signal is the purpose that can reach accurate measurement number of pulses.

To achieve the above object, the technical solution adopted by the present invention is that:

A kind of pulse counting method based on SoC utilizes analog comparator, timer, direct memory access device and the place of SOC It manages device cooperation and carries out step-by-step counting, specific as follows:

Firstly, carrying out Initialize installation to analog comparator, timer and direct memory access device:

The comparison threshold value of analog comparator is set, and setting timer is input pattern, and setting direct memory access device is cyclic module Formula, and the triggering mode of direct memory access device and its initial value of counter Counter are set；

Then, starting timer starts to carry out step-by-step counting:

When pulse signal is via analog comparator, if pulse signal is higher than the comparison threshold value of analog comparator, digital arteries and veins is formed Signal is rushed to be input in timer；

Digital pulse signal is input to direct memory access device by timer, according to the triggering mode of direct memory access device, number Word pulse signal triggers DMA event, subtracts 1 for the counter Counter of direct memory access device, while by the counter of timer It resets；

When pulse signal stops, the counter of timer, which is counted, generates Update event interrupt until overflowing, at this point, place The value that device reads the counter Counter of direct memory access device is managed, and calculates the number of pulses of pulse signal, number of pulses Initial value-the Counter of=Counter.

The triggering mode of the direct memory access device is failing edge triggering mode or failing edge triggering mode.

The initial value of the counter Counter of the direct memory access device is 65535.

After adopting the above scheme, the present invention be used only to an analog comparator of SoC, a timer, one directly Internal storage access device, resource consumption is considerably less, and only terminates to be measured preprocessor in signal and just intervention is needed to handle, and accounts for It is very short with the time of processor, so, without excessive operation time, thereby reducing arteries and veins in entire pulse counting process Rush the time-consuming counted and the bring error due to time-consuming excessive.Moreover, comparison of the present invention by setting analog comparator Threshold value, come avoid system to pulse signal interference and caused by measuring error.In entire pulse counting process, SOC does not increase Add external circuit, also the maximum time width T of setting pulse signal, the more not intervention of software are not achieved that accurate survey Measure the purpose of number of pulses.

Detailed description of the invention

Fig. 1 is invention's principle block diagram；

Fig. 2 is Initialize installation flow chart of the present invention；

Fig. 3 is Update interrupt processing flow chart of the present invention.

Specific embodiment

As shown in Figure 1 to Figure 3, present invention discloses a kind of pulse counting methods based on SoC, utilize the simulation of SOC Comparator COMP, timer Timer, direct memory access device DMA and processor MCU cooperation carry out step-by-step counting, specific as follows:

Firstly, carrying out Initialize installation to analog comparator COMP, timer Timer and direct memory access device DMA: setting The comparison threshold value of analog comparator COMP, setting timer Timer are input pattern, and setting direct memory access device DMA is to follow Ring mode, and the triggering mode of direct memory access device DMA and its initial value of counter Counter are set.Specifically, directly The triggering mode of internal storage access device DMA is failing edge triggering mode or failing edge triggering mode, and counter Counter's is initial Value is 65535.

Then, starting timer Timer starts to carry out step-by-step counting:

It, can if pulse signal is higher than the comparison threshold value of analog comparator COMP when pulse signal is via analog comparator COMP Digital pulse signal is formed to be input in timer Timer.

Digital pulse signal is input to direct memory access device DMA by timer Timer, and digital pulse signal is in failing edge When trigger DMA event, the counter Counter of direct memory access device DMA is subtracted 1, while by the counter of timer Timer It resets.If there is pulse signal inputs, then the persistently counter O reset to timer Timer, when pulse signal stops, timing The counter of device Timer, which is counted, generates Update event interrupt until overflowing, and processor MCU reads direct memory access device The counter of DMA, and the number of pulses of pulse signal is calculated, number of pulses=65535-Counter.

The present invention is used only to an analog comparator COMP of SoC, a timer Timer, a direct memory and visits Ask device DMA, resource consumption is considerably less, and only terminates to be measured preprocessor MCU in signal and just intervention is needed to handle, and accounts for Time with processor MCU is very short, so, without excessive operation time, thus reducing in entire pulse counting process The time-consuming of step-by-step counting and the bring error due to time-consuming excessive.Moreover, the present invention passes through setting analog comparator The comparison threshold value of COMP, come avoid system to pulse signal interference and caused by measuring error.In entire pulse counting process, SOC does not increase external circuit, and also the maximum time width T of setting pulse signal, the more not intervention of software are not just realized The purpose of accurate measurement number of pulses.

The above is only the embodiment of the present invention, is not intended to limit the scope of the present invention, therefore all Any subtle modifications, equivalent variations and modifications to the above embodiments according to the technical essence of the invention still fall within this In the range of inventive technique scheme.

Claims

1. a kind of pulse counting method based on SoC, it is characterised in that: the method utilizes the analog comparator of SOC, timing Device, direct memory access device and processor cooperation carry out step-by-step counting, specific as follows:

Then, starting timer starts to carry out step-by-step counting:

2. a kind of pulse counting method based on SoC according to claim 1, it is characterised in that: the direct memory is visited The triggering mode for asking device is failing edge triggering mode or failing edge triggering mode.

3. a kind of pulse counting method based on SoC according to claim 1, it is characterised in that: the direct memory is visited The initial value for asking the counter Counter of device is 65535.