I have a question on modifying the NXP LPC1114 target for Tutorial A9.
To allow the ChipWhisperer-Lite to interface with this board, we’ll need to make some small modifications to the board:
4. Cut the traces on 3.3V_CORE and 3.3V_IO_E.
5. Add a 12-ohm resistor on the 3.3V_CORE jumper.
In Step 4, I interpreted the cutting of both traces (see below) as a mean to disconnect the 3.3v power supply to the chip, and subsequently providing power via the SMA glitch port of the Chipwhisperer.
If my interpretation is correct, what is then the purpose for adding the 12-ohm resistor in Step 5?
By adding back a 12-ohm resistor, the chip then draws power back from the 3.3v power supply. Will we then still be able to voltage glitch it?
I also noticed on Dmitry’s blog series that he did not use a resistor across the 3.3V_CORE jumper. Instead, he supplied glitch power directly to both 3.3V_CORE and 3.3V_IO_E jumpers. Any idea why is this so?