I am measuring the power consumption during the execution of a bunch of codes. But, I would like to know for my execution what is the frequency of the target board? and is it supposed o be the same as the frequency of the chipwhisperer? if not how does this affect the sampling?
How can I figure out the sampling rate i.e., how many samples / clock cycles
Yes, ADC is sampling at 4x the victim’s clock frequency.
| The input frequency from the EXTCLK source in Hz.
| This value is used to help calculate the correct CLKGEN settings to
| obtain a desired output frequency when using EXTCLK as CLKGEN input.
| It is not a frequency counter - it is only helpful if the EXTCLK
| frequency is already known.
EXTCLK is an external clock that you can optionally provide on the HS1 pin, in cases where the victim’s clock is not sourced from ChipWhisperer. In your case, with our STM32F4 target, you don’t need to worry about that, and so extclk_freq is not relevant.
If you set scope.clock.freq_ctr_src = 'clkgen', then you should see that scope.clock.freq_ctr is around 7.37e6.