interrupt related

is there any way in which every pin of microcontroller can act like an external interrupt pin?:-/

its not possible to act every pin as Interrupt pin. Here is the way to scan all the lines in minimum amount of time. based on that you can set or clear the interrupt
flag.

with some digital logic it is possible...
something like this.. sorry i do not have orcad with me


when interrupt occurs. you need to check low level on the four GPIOs used.