hi;
why not switches that pull from high to
low on press and one n input and gate?wired
AND as in I2C could also be used. also same
lines could be connected to port pins.these
pins could be read in ISR( on receiving 1-0) . but care must be taken to pull that level again to 1 after processing.if it cant be disabled directly then using a timer and alternate enable/disable interrupts may work.or else simple edge triggering.
regards
pranav