My environment is Atmel SAMD21 Xplained pro board.
It was running fine until I change GCLK register to the wrong position.
After the wrong register hex file was programmed, communication over openocd is no longer be done.
I tried to find out how to solve this but there's no exact issue like this or any good explanation.
I dunno much about the mechanism of the EDBG or any debugger. Or the solution for this is to use external debugger to reprogram?
Attached screen shots are the report from openocd.