Is my CPU in HALT (IDLE) or STOP mode?


Joined Jun 4, 2014
X1 is 0hms to GND either when power On or OFF.
Then that is your fault.
It might be the capacitor on that pin; It might be the chip itself with an internal short; it might be a fleck of solder/wire/etc shorting that pin to ground.
If the chip is in a socket, remove it and see whether the short is in the chip or on the board.

Thread Starter


Joined Dec 22, 2018
Thanks for your help Albert. I will get the test done.

If I understood:

- The processor turns ON
- It does all the INT, RESET and NIW check.
- If required it goes on STOP or HALT mode then the processor internally shorts its X1 pin to VSS as an instruction.
- The processor turns OFF and the instruction in form of current that sustained the short of X1 pin to VSS is lifted.
- Then when testing the X1 to GND with the processor of it should never be 0ohms.
- If the short stays after the processor is OFF then it is physically and internally shortened.