i didn't use motorola, but interrupts don't change much from chip to chip i think.
so if you want to make an interrupt, then you need to connect your button to an interrupt pin, then you need to write your code in the proper location of memory. that's all i think.
another way in 80x86 series chip that you signal to IR pin (interrupt request), then send your interrupt address (which your code is located) to the databus.
in motorola they will be similar, i think.