MC9S12DT256: Assigning external interrupts to port pins

[swaroop]

Hi,

I am desiging a board with the MC9S12DT256 MCU on it. I have a requirement of assigning two external interrupts from two external communication chips to the interrupt inputs of the MCU.

I have decided on using PJ0 and PJ1 (Port J) of MCU as edge triggered interrupt inputs for these external interrupts.

I do not want to use XIRQ or IRQ.

Please tell me if I can use PJ0 and PJ1 as external interrupt inputs.

Regards

Swaroop

[mke_et]

I've not used 'J' but I've done a system that used P and H for port pin interrupts. Just remember, you get a single interrupt for the port, then you have to divide the input as to what it was. And write you ISR so that it can handle the case of a second pin kick coming in while the first is being processed. The easiest way I found is to write your ISR so the 'kick' is generic, then loop until all the pins are clear, then exit on a clear port.

Mike

[Aditya]

Can you post the code that you are working on? I am in a similar dilemma and  even after making a number of manupulations, my code does not enter into my ISR. I just wanted to know how we can handle them.