Fast Digital Capture to Analyze Frequency

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joeac_1591236
Level 2
Level 2

I want to be able to measure the frequency of an incoming square wave signal (0-5V).  Because I want to be able to use equivalent-time sampling to measure frequencies above the max CPU frequency of the PSoC, I simply want to be able capture high or low as fast as possible (at regular, known intervals) and store the results for processing.  

   

Is there a way to do this with a digital input pin?  Or do I need to use a serial communication block like SPI?

   

Thanks,

   

 - John E.

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3 Replies
himam_31
Employee
Employee
50 likes received 25 likes received 10 likes received

Hello John,

   

If you are keeping the BusClock to a low frequency and configure the MasterClock to higher value then this is possible. If already the BusClock is very high, then this will not be possible.

   

Thanks,

   

Hima

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HeLi_263931
Level 8
Level 8
100 solutions authored 50 solutions authored 25 solutions authored

You could setup a DMA, triggered from a clock, that stores a sample of the signal (captured by a status register) into memory.

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This is exactly what I was looking for.  Thank you hli.

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