I am trying to work out how to scan a 3 x 4 matrix keypad using porta 0-2 and portB 0-3. The reason is that I am using portb 6 & 7 for ICSP so I consider that they are not really available. I am a bit new to this so please bear with me.
Am I right in thinking that I need to pull porta pins high with pullup resistors, set portb 0-3 high and then take each portb pin low one at time and read the port a result? Is that how it works? Do I need pull up resistors on portb 0 - 3? I am using a 16f627

Thanks