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Altera_Forum
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14 years ago

Unused CPLD Pins

I have two CPLDs on my PCB that connect to a common SPI bus. In order to keep things simple I'm trying to talk to only one of the chips at first but I'm having some trouble with the voltages which le...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
14 years ago

The problem can't be clearly understood from your schematic snippet, there's e.g. no 22 ohm resistor, so it's unclear which pin you're exactly talking about.

But input with weak pull-up is the better setting for unused pins, particular if there's a small chance that they may be ever driven by external signals.