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newaetech / chipwhisperer

ChipWhisperer - the complete open-source toolchain for side-channel power analysis and glitching attacks
http://chipwhisperer.com
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`as_int` argument when capturing traces on ChipWhisperer-Lite gives wrong length #426

Closed Stian108 closed 1 year ago

Stian108 commented 2 years ago

Using as_int=True on ChipWhisper-Lite gives a trace longer than scop.adc.samples. In my case a trace of length 5190 instead of 5000. It also seems like the traces are misaligned at the start. This seems to stem from the float data being aligned to the trigger in processData in _OpenADCInterface.py, but the int data is not aligned in the same way. This seems like unintended behavior to me, as I expected the only difference between as_int=True and as_int=False to be the normalization and type of data, as the documentation indicates.

Thanks in advance for taking a look at this :)

alex-dewar commented 2 years ago

Thanks for the report on this. Yeah this is definitely not expected behaviour. I'll post an update when I've fixed or had more time to look into this.

alex-dewar commented 1 year ago

Quick update on this: I've fixed the issue. There was both a misalignment from not using the trigger part of the adc data and additional data that gets cut off during scope.sc.readData().

I'm on a branch for the next ChipWhisperer release and will close this once I merge back into develop