This means that the user could download the relationship between the port pins using the serial port, the relationships could be AND, OR, XOR, NOT
Which YOU will have to program for him/her.

So many projects have been misguided by the thinking "We can make such a unit, it will be easy for the customer to change the program". WRONG, you will get constant phonecalls "how do I do this" and "do this for me" and the end result will be that customer support cost you 10 times more than the profit you made on selling the thing.

Many programmers/engineers are so exited by 'making it easy' and do not realize that the customer will NOT (want to) understand how to program the unit.

Go ahead and make your thing, but do not say you were not warned.

Erik