SCA101 Lab 3_3 Always with wrong results

Hi everyone, I’m having some problems doing the Lab 3_3, I always got the wrong results so I tried seeing the solutions notebook and usings it’s code but it’s still getting wrong results.

I’m using the CWNANO and here’s some images:

The correct byte is not even on top 5:

On the windowing peaks block code:

The SNR on the Nano is much worse than the Lite/Husky/Pro, so you’ll likely need a lot more traces than is currently in the lab. You may want to skip this one - you should see much more success on the CPA lab (4_2).

Alex

Thanks for the tip! Another question, is there a way to know the sampling rate of the CWNano? I saw that the max is 20MS/s but I wanted to know the exact rate for some calculations.

Just for posteriority, I had success with lab using 20000-25000 traces.

Good to hear you got the lab working. Regarding the sample rate, you should be able to get/set that value via scope.adc.clk_freq. It’s pretty limited in what you can set it to, though. It’s just a divider of the (96MHz IIRC) microcontroller clock, so you can get 1/2 that, 1/4, etc.

Honestly, I wouldn’t worry too much about the actual sampling frequency - it’s much more important to have an ADC clock that’s phase locked to the target clock. Both the target clock and the ADC clock are generated from the same 96MHz clock on the Nano, so you don’t have to worry about that.

Alex