# ATMega644PA possibly bricked by setting fuses with avrdude

I have been programming an ATMega644PA with avr-gcc and avrdude on linux for a little while with no problems. Well until I decided to change some fuses. I had been using the option for avrdude -p ATMEGA644P for programming the chip even though the chip is ATMega644PA.

After reading the data sheet (and reading the fuses on the chip) I did the following

avrdude -v -c avrispmkII -p ATMEGA644P -P usb -U lfuse:w:0x63:m


The chip would no longer communicate. I realized after that the problem may have been that I set the bits for external clock rather than crystal oscillator but even with using an ATTiny to generate a 1MHz signal to the proper pin on my Mega644, I still get nothing.

Any ideas as to why the chip is unresponsive? Could it be that using avrdude's definition for the P version of the chip rather than the PA version is the cause?

And finally, What can I do to rescue my chip? Ive heard that it may be possible with High voltage programming or JTAG. Would I be able to do that with an STK500?

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 First, welcome to the site! I hope we can offer you a warm welcome, but your question might be a dupe. These questions: chiphacker.com/questions/700/… , chiphacker.com/questions/717/… , and chiphacker.com/questions/861/recovering-an-attiny13 also refer to fuse settings on AVRs. But, this is a different chip (slightly), different fuse settings, and a different programmer, so I say we let it stand (And I don't have the rep to flag it). – Kevin Vermeer Jun 20 '10 at 22:43