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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

Driving unused pins to GND (or VCCIO) requires definition of all connected hardware pins in the top design, even if they are yet unused. This is a serious disadvantage to my opinion. Thus weak pull-up (or bus-hold) is the best selection for most designs. Interestingly, the Quartus default has been changed to weak pull-up with newer devices (most likely to avoid I/O driver damage with shorted pins).