I am trying to design an application that uses Attiny24. This is a handheld app. and I would like it to have ISP capability so I can reprogram it on the board and don't have to remove the micro from the board. I know the Tiny has the 6 pins needed for the ISP connector.
Since the three pins (7,8,9) can be used as ports as well, is it possible to hook these pins up in my board in such a way so they can be used as general purpose input/output pins and also be able to use them as ISP pins? Can there be a switch on my board that will choose between ISP function or normal port pins? Or does this have to be in software?