I have a question regarding the behaviour of a MCU's GPIO pins when configured in a certain way in hardware and software. In this case I am using a dsPIC33EP, but I believe this question is generally applicable to MCUs with push/pull outputs. At certain points in the circuit I am developing I need a pull-up resistor on the line to ensure that the connected chip has a hardware default state (in this case HIGH) even when the PIC has been turned OFF. If I pull up this line to a voltage equal to or greater than the power supply of the PIC (3.3V) but the PIC outputs a HIGH at slightly-below whatever this voltage level is... what happens to the output of the PIC?
I am using a 5V-tolerant pin on the PIC, which in the electrical specifications guarantees that it will tolerate up to 3.6V when the PIC is off, so that is not an issue. What I am uncertain about is how the PIC handles a (small) over-voltage condition on an output through a pull-up resistor.
If Vp is greater than VOH, will there be damage done to the chip?
On a side note, I have considered some solutions to this problem and will likely set up these outputs in software to behave as open-drain types. My question is regarding the feasibility of doing it using PUSH-PULL outputs, but if anyone has any other simple solutions to offer for application's sake, please feel free!