General questions

I’m working with Chipwhipserer Lite, when i took traces in my Y axis y have “data” and X axis i have sample. First “data” is the current of the microcontroller? The voltage? how is the zero choosen? and second, in my X axis i have 4 samples per microcontroler clock cycle?
Another question i have is how can i choose the optimization level of the compiler. CwLite use WinAVR 20100110 GCC-4.3.3 (right?), there are 4 levels of optimization, how can i choose and see wich one im using.
And last, in chipwhisperer capture is a way to see how long it take to run the cipher algorithm? I mean the time it takes to encrypt 16 bytes of plaintext.

Hi,

ChipWhisperer is measuring AC coupled voltage at the low side of a shunt resistor, which is proportional to current. “0” is the average voltage on the low side of the shunt resistor. Also you’re correct in that you have 4 samples per microcontroller clock cycle.

You can choose the optimization level via the OPT makefile variable. So something along the lines of:

make PLATFORM=CWLITEARM CRYPTOT_TARGET=TINYAES128C OPT=2

You can see the number of ADC (not device) samples between the trigger_high() and trigger_low() calls by scope.adc.trig_count.

Alex

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[quote=“Solved by Alex_Dewar in post #2, post:2, topic:2053”]