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Altera_Forum
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9 years ago

About unused pins of CycloneIV

Hi:

I found the states on cyclone® iv device family pin connection guidelines.

It says "The unused pins must be connected as specified in the Quartus II software settings. The default Quartus II setting for unused pins is 'As inputs tri-stated with weak pull-up resistors', unless for specific pins that Quartus II software connects them to GND automatically."

Does it mean designer is allowed to leave all the unused pins open/unconnect on PCB and keep above setting in quartus II?

Is it correct way of dealing with unused pins?

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  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    9 years ago

    --- Quote Start ---

    Does it mean designer is allowed to leave all the unused pins open/unconnected on PCB and keep above setting in quartus II?

    --- Quote End ---

    Yes, it's the usual way to deal with unused pins. Unused pins that should be connected to ground are the Cyclone III/IV clock pins that don't have a weak pull-up.