Is a pin pulled to the ground a symptom of a dead ATMEGA?

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#1
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Hey guys,

I'm posting here because a pin on my ATMEGA644 (PC2 to be precise) is being pulled down (even when the atmega is not being powered).
The internal resistance (in the ATMEGA itself) between this pin and the ground went from 1.5k to 350 ohms (tested when not powered) when I added a pull up resistor to counter act the effect of this parasite pull down (as this pin was configured as input).

This pin hasn't suffered any bad treatment, it was configured as input with internal pull up, and a button was connected to it.

Thus, I was curious if anyone already had this problem, and if it is common?

Let me know if i am not clear enough :)

My electronic projects blog >> www.limpkin.fr

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I cannot help noticing that PC2 is TCK so what happens if you flip the state of JTAGEN? (FAQ#5)

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JTAG is of course disabled (by software & fuse actually)

My electronic projects blog >> www.limpkin.fr

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Quote:

of course

Sorry but why is it "of course"? I stared deeply into my crystal ball but in the wisps of clarity I saw no such detail.

And what would be the point in doing both by fuse AND software?

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sorry for the misunderstanding :). I'm not a beginner in AVR uC.

No reason, just as a precaution in the event I would forget to set the fuse.

My electronic projects blog >> www.limpkin.fr

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limpkin wrote:
Thus, I was curious if anyone already had this problem, and if it is common?
I've seen this plenty of times, where only one pin on the AVR is damaged and everything else works fine. For me this has been the most common failure type when using AVR's.

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i also had a same type of experience! when pin PD2 of Atmega8 got damaged and was pulled down to grnd! although the rest of the pins were OK.
I could even program the chip, meaning the problem is with the PIN only !

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Thanks a lot for your feedback :)

My electronic projects blog >> www.limpkin.fr

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i also have the problem with M8 and M64 TQFP Package.