search

cr1901 / freq_count

Migen/MiSoC frequency counter, based on ideas from http://hamsterworks.co.nz/mediawiki/index.php/High_Speed_Frequency_Counter
0 stars 0 forks source link

Performance, etc.? #1

Closed npisenti closed 7 years ago

npisenti commented 7 years ago

I was wondering if you ever got this frequency counter functioning to your satisfaction... I was about to implement something similar when I saw this repo! Were you able to get similar speeds to what was reported @hamsterworks?

cr1901 commented 7 years ago

I was able to get this to work up to 240 MHz; that's as high as I tested, but I'm sure it will work at higher frequencies. However, this repo was never meant to be used standalone; it was a PoC meant for debugging for the HDMI2USB project.

The code eventually evolved into this: https://github.com/timvideos/HDMI2USB-litex-firmware/blob/master/gateware/freq_measurement.py

If you're familiar w/ Migen/MiSoC, feel free to rework to your own needs.

npisenti commented 7 years ago

Thanks! I'm somewhat familiar with migen/misoc, and intended to build a frequency counter + digital loop filter to stabilize an optical beatnote between two lasers as a real-world project to understand them better. I'll take a look at your implementation, and might steal some inspiration!