CW-Lite voltage glitch multiple times

1

Hello, from what I understand the CW-Lite does not allow triggering/glitching off a GPIO line 1 time at a specified time after AND then a second time at a specified duration (only 1 gpio trigger event). The second time glitch is allowed only on the Husky?

I currently have 1 glitch upon resetting the processor working, but it seems I need a second glitch to get past the second stage protection.
Note: This is executing in boot ROM so I can’t add GPIO flips in the code itself.

Right now i’m triggering off a reset line of an STM32 processor. I’d prefer to have 2 glitches based off the reset line. If that isn’t possible, trying to figure out different ways to achieve the same results.
So, I’m looking at options:

  1. Set up a second microcontroller to do the glitch via a fet
  2. Set up a second microcontroller to sample the reset line and set a gpio out, then flip a gpio a period of time after that. And I could set continuous glitching so it just triggers off both gpio flips
  3. Figure out how to implement what this person did. I’m thinking this will be too painful.
    Multiple glitches · Issue #127 · newaetech/chipwhisperer · GitHub

erm it seems what i really want is num_glitches but it is husky only.

2

That’s right, scope.glitch.num_glitches is what you want but it’s only available on Husky.
#1 and 2 could work.
Re: #3, there are two issues; one is coding the new logic correctly (not too hard), the other is making it fit and rebuilding the FPGA bitfiles. The CW-lite FPGA is pretty maxed out, which makes additions like this challenging; it was one of the reasons for moving to a larger FPGA for Husky.

3

Thanks! I ended up using #2 to sample the reset line with a comparator and then triggering which worked.

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