Electronic – Microcontrollers: What to do with unused non-IO pins


There's plenty of information on what to do with unused IO-pins on a microcontroller. You can set them to a floating output, ground them, or pull them up to Vcc or down to ground. However I can't find any information on what to do with non-IO pins. Do the same rules apply to those, or can they simply be ignored when they're not being used?

EDIT: Sorry for being unspecific. The microcontroller I am using is a Microchip PIC18F4550, and it has a Vusb-pin (non-IO). I was looking for a general answer for how to treat non-IO pins, but I guess it's specific to the individual pins.

Best Answer

The data sheet for your micro will have a brief pin description for all pins that will generally tell you what to do with it if is going to go unused. For example, if pin x is unused, connect to 100nf capacitor to ground.