Maximum IO pin input voltage

[jlastofka]

I've been searching the forum and the processor documentation but I can't seem to find the spec for the allowable input voltage on the digital IO pins. I saw one spot showing the Logic 0 and 1 levels for a 5V supply and a 3.3V supply setup, but not the maximum allowable.
Is it 5.5V, same as the max battery supply voltage? Does it depend on whether you're powering it from 3.3V or 5V (I doubt that)?
Someone telling me the value is somewhat helpful, but I'd like to know where it's listed officially.
Thanks.

[jlastofka]

I found the Microchip (manufacturer) spec for the processor and it says the maximum input voltage on the input pins is Vdd + .6V, so since we're running the processor on 3.3V the absolute max allowed Vin on the I/O pins is 3.9V

I'm going with that.