I know its not atmel MCU im using, but i figured that i might get some help here, since from what i know here are people with superior knowledge about the electronics in general.
My best guess is that CC-debugger used to program the BLE112 module in the board does kill the STM32 mcu i'm using(third mcu just died yesterday), when certain thing happens.
there is atleast one thing i did overlook with the PCB connections which is the RESET pin of this BLE112 module, both CC-debugger and MCU connects to this pin from same NET without any current limiting between those.
So, is it possible that since i use the gpio as output from the mcu to control the reset state, and then attach the debugger to program the ble module, which also starts driving the reset pin, that it does source so much current that it kills the mcu?(there is no current limiting between the CC-debugger and MCU in place)
While i did program the BLE module the GPIO of MCU was logical 0(low) and programmed as output, after programming the BLE module, i still got connection to the MCU and did set the GPIO to high to let the module operate again, after that the fuse did blow almost instantly and the MCU was shorted.
this is the internal connection of GPIO pin for the MCU, if it helps.
Is there any remote chance that this could kill(short) the GPIO pin/port from the MCU? my knowledge is not enought here now.