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Altera_Forum
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18 years ago

Connecting unused pins

Hello everyone, I have a design using a Cyclone III, with some unused pins. I wonder what would be the best recommendation about what to do with these pins. By default Quartus reserve these p...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
18 years ago

I don't know why I didn't notice it at first but there is also the option "reserve as input tri-stated with bus-hold circuitry". In that case the logic level on the unused pin is sampled at the end of configuration, and maintained during user mode. I could use this mode and connect half the unused pins to ground, and the other half to vccio, couldn't I?

Or is it better to stick everything to ground and don't really care about vcc sag?

Thank you!