How to set value of clock cycles?

Embedded Security ChipWhisperer Software
1

How to set value of clock cycles, which is necessary for setting of DES. As mentioned in .c file of DES.

uint8_t encrypt(uint8_t* pt, uint8_t len)
{
/* Do Encryption /
//NOTE: Setup for DES is huge - about 15000(!) clock cycles. This results in
// a large and annoying offset.
// Instead trigger_high() is called within the DES algorithm.
//trigger_high();
uint8_t ct[8];
des_enc(ct, pt, key); / encrypting the data block */
trigger_low();
simpleserial_put(‘r’, 8, ct);
return len;
}

In above code it is mentioned to set 15000 clock cycle

2

Maybe your question is unclear, but the number of clock cycles is a property of the code; it’s not something you can “set”.

3

here in DES.c code which is in avrcryptolib it is mentioned in the comment to setup 15000 clock cycles, my question is simple: how it is possible to set such a large value in python code?

I mean does scope has property of clock cycles, as I was not able to find this its official api guide.

4

This likely refers to how many target clock cycles you need to sample. By default, scope.adc.samples corresponds to 4 target clock cycles, so you’d need to set scope.adc.samples = 60000. If your capture devices doesn’t support this many samples, you’ll need to change scope.clock.adc_src so that 1 sample corresponds to 1 target clock cycle.

5

Thanks @Alex_Dewar for clarification!