How to take out trigger on an oscilloscope?


#1

Hello!!I’m using chipwhisperer lite two version. I want to display the entire rsa waveform on my osciloscope since the sample buffer is too small (only 24.400 samples). Is there any pin on chipwhisperer so to take the trigger signal or a similar procedure in order to achieve this???


#2

If you were using IO4 to trigger the CW-lite, you’ll find a copy of it on the 10-pin header right above the 20-pin connector (you’ll have to solder the header).

Jean-Pierre


#3

And if you want to trigger at the same time as the CW is starting capture you would need to use the TRIGOUT test pin.
See:


#4

As TRIGOUT pin isn’t routed on FPGA, which pin should I take in order to achieve capture the trigger signal on an oscilliscope?? Pin P105 doesn’t seem to appear anywhere.


#5

What about an other solution without having to solder the header?


#6

Hi,
If you’re not using an offset, then IO4 and TRIGOUT are effectively the same!
What’s your target? If you’re using the CW308 UFO board, then there is already a header with IO4 there for you.
Another option is to use individual jumper cables instead of the 20-pin connector between the CW-lite and your target, so you can route the IO4 pin onto your scope.
Hope this helps,
Jean-Pierre


#7

I’m using CW lite 303 two part version with the XMEGA target. Is there any individual pin for the trigger signal so as to use the promt from my oscilloscope in order to capture the entire trigger signal?


#8

In that case, your only option not involving soldering is to use individual jumper cables (example) instead of the 20-pin connector, so that the IO4 output from the target can be connected to your scope.
Look here for a definition of the pins on the connector: https://wiki.newae.com/CW1173_ChipWhisperer-Lite#20-Pin_Connector
Just be careful not to short anything out!

BTW another option to get around the CW-lite 24k sample limit, since you are using the XMEGA target, is to sample with the CW-lite 24k samples at a time by repeating the same operation and using a different offset each time, then stitching the traces back together.
i.e. follow these steps:

  1. collect 24k samples with offset=0
  2. repeat same operation, collect 24k samples with offset = 24k
  3. repeat same operation, collect 24k samples with offset = 48k
    etc…

Jean-Pierre