I have two identical boards both equipped with ATxmega128A. I am using Atmel-ICE for programming using PDI Interface.
- The first board, I can read the device signature without any issues.
- On the second board, the error "unable to enter programming mode" appears.
After some trial and error, I changed the PDI Clock of Atmel ICE from default 4MHz to 1MHz. Now I am able to read the signature of both devices.
Question: How is it possible that 100% identical boards where one works with 4MHz PDI Clock and the other one only with 1MHz PDI clock?