12F675 - How to configure the INTCON command to activate the various interrupts?

[mpgmike]

To activate a single I/O pin as IOC (Interrupt on Change) you use the "IOC" Register; Register 3.4 in the Data Sheet:

IOC.0 = 1  'Enables IOC on GPIO 0

If you want to enable IOC interrupts on multiple GPIO pins you can use the IOC Register in binary mode. Assume you want an IOC Interrupt on GPIO pins 0 & 1:

IOC = 000011  'Enables IOC on GPIO 0 & 1

Then you must enable IOC interrupts using the INTCON Register:

INTCON.3 = 1  'Enables IOC Interrupts

Next, you need to create an Interrupt Handler (See PBP Manual) so when you get the Interrupt, you can do something with it. In your Interrupt Handler, when you get an IOC interrupt you have to clear the Interrupt Flag:

INTCON.0 = 0  'Clears IOC Interrupt Flag

If you need more than one GPIO IOC Interrupt (2 or more Port Pins), you will have to Poll which GPIO triggered the IOC Interrupt:

IF GPIO.0 = 1 THEN
  <Interrupt Handler Code for GPIO.0>
ELSE IF GPIO.1 = 1 THEN
  <Interrupt Handler Code for GPIO.1>
ENDIF

The above code assumes that a low-to-high transition triggers your IOC interrupt. You may need to change that depending on your goals.

<edit> I tried to write "IOC = 000011 'Enables IOC on GPIO 0 & 1" but the forum keeps changing it to "IOC = 000011 'Enables IOC on GPIO 0 & 1"