[time-nuts] Question about frequency counter testing
Hal Murray
hmurray at megapathdsl.net
Fri Apr 27 09:30:01 UTC 2018
olegskydan at gmail.com said:
> No, it is much simpler. The hardware saves time-stamps to the memory at each
> (event) rise of the input signal (let's consider we have digital logic input
> signal for simplicity). So after some time we have many pairs of {event
> number, time-stamp}. We can plot those pairs with event number on X-axis and
> time on Y-axis, now if we fit the line on that dataset the inverse slope of
> the line will correspond to the estimated frequency.
I like it. Thanks.
If you flip the X-Y axis, then you don't have to invert the slope.
That might be an interesting way to analyze TICC data. It would work
better/faster if you used a custom divider to trigger the TICC as fast as it
can print rather than using the typical PPS.
------
Another way to look at things is that you have a fast 1 bit A/D.
If you need results in a second, FFTing that might fit into memory. (Or you
could rent a big-memory cloud server. A quick sample found 128GB for
$1/hour.) That's with 1 second of data. I don't know how long it would take
to process.
What's the clock frequency? Handwave. At 1 GHz, 1 second of samples fits
into a 4 byte integer even if all the energy ends up in one bin. 4 bytes, *2
for complex, *2 for input and output is 16 GB.
--
These are my opinions. I hate spam.
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