ATMEGA64 ISP Question

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Hi

I have just built a new PCB and assembled it, plugged in my AVRISP2, powered on and clicked "Read Signature" .... to be greeted with the dreaded "Entering Programming Mode....Failed" Message.

I have made the ISP connections the same as I have for many previous successful ATMEGA16 projects, but the ATMEGA64 has an extra PEN pin. Should this be hi / lo / disconnected? I have actually tried it all ways, but it would be good to know what it should be!

I know my programmer works (tested with other ATMEGA16 projects).

This is my first try at using the ATMEGA64 - I'm obviously missing some important point...

I have attached my circuit for your comments.

If someone could post a known good circuit I could copy, that would be super helpful.

I look forward to your suggestions!
Thanks
Pete

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Total votes: 0

The mega64 and mega128 are unusual amongst AVRs in that they do not use the SPI pins for ISP. Time to hit that datasheet again. (they are TXD0/RXD0).

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clawson wrote:
The mega64 and mega128 are unusual amongst AVRs in that they do not use the SPI pins for ISP. Time to hit that datasheet again. (they are TXD0/RXD0).

Wow, that I did not expect!

Thank you so much for pointing me in the right direction!

Cheers
Pete