I am running a bunch of code on different target boards using cwlite and stm32f3, stm32f4, and xmega. Surprisingly the traces are very different from each other., i.e., for xmega and stm32f3 the leakage can be seen (a loop through a table of 13 entries where I compare an element x to each entry and add 1 if the condition is satisfied otherwise I do not add 1. The addition of 1 can be seen in red. A bit flipping is also executed at the end and can be detected) however, in stm32f4, the secret data were difficult to read with a naked eye directly from the traces.
Is there an explanation of this observation?
Traces on STM32F3
Traces on STM32F4
Traces on XMEGA