No the diode will have a forward leakage current, therefore your pin will see the voltage on the other side. You should use a zenner or rail clamping diodes and a seriese resistor to protect your pin.
No it is being provided through the diode from the 16V supply. The internal protection diodes are clamping the input that is why you don't see 16V.What is the diode in the 16V line doing? I can't see the point in that.
So eventually it is going to burn out the internal protection diodes.
QuoteSo eventually it is going to burn out the internal protection diodes.Probably not, they are good for about 1mA which is much less than you are giving them. Personally I don't like relying on them, but I don't have any solid reason. If it were me I would have used a transistor into the input pin, but you should be fine.
Is that right?
I believe the internal resistors are 20k? or is that just the pullups?