Interfaceing another PIC? Replacing a existing Digital chip with My PIC

[wdmagic]

chirpy, thats a maximum rating, in the notes on the side it states its using a 5volt logic supply.
its like most PIC's have a 5.5v max, but we never run them at that. I can only assume they designed it that way to be able to use 6volt external/isolated supplys , the internal componets probobly regulate the voltage a bit or have isolation parts for the interfacing.

NOTE: if you look on page 4 it says normal range is 5 volts and max is 5.5, im not sure why they say 7 on page 1 as a max.