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[DPRG] Frequency Counter Question

Subject: [DPRG] Frequency Counter Question
From: Clay Timmons ctimmons at cadence.com
Date: Mon Sep 29 11:27:01 CDT 2003


All your math looks right to me   

1MZ signal at 10usec gate = 10,000 counts

10^6 cycles/second * 10^-3 second = 10,000

But you are getting way more counts than that.   
Are you counters counting on the rising edge, falling edge or both edges?
Also make sure that the signal going into the counters is a clean rail to rail swing with no bounces or noise.



> But then the big question is....
> Does this sound right or have I gone insane at the moment?
> I amgetting something like 49,652 for a count at 1mhz (really really
> close though something like 1.00034565mhz). Maybe I have the timers set
> wrong.
> Or do I?

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