CW308 target voltage does not recover from GND when GlitchSettings.repeat is set to 1

I connected the Chipwhisperer Pro to the CW308 STM32F board and ran the tutorial SOLN_Fault 2_1. As a result, a reset occurred, but without success.

In order to achieve success, I was changing some parameters and discovered that only when setting scope.glitch.repeat to 1, the target supply voltage is not recovered from GND after the glitch.

*Voltage was measured by connecting a probe to TP5 and GND of the CW308.

When repeat is set to 2 or higher, the voltage returns to its original level after the glitch.

Is this correct behavior? Is there any way to solve this problem?

When I set the repeat to 2, the voltage changes as follows.


Thanks for the report on this. This is a bit of a known issue - as far as I can tell, this seems to depend on glitch offset and width as well (at least it did in the past) and it changes with different bitstreams. Unfortunately, we don’t really have a full fix right now, so the recommendation is to switch the glitch on/off after each attempt to prevent Vcc from staying low.



Thank you for your reply. I understand that it is not an equipment failure. Does this occur with Chipwhisperer Lite as well?

Yes it does, though I think the exact conditions that make it appear likely differ a bit from the Pro, as it seems to change based on the bitstream.


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