Newbie question about interrupts

M3H0 — Thu, 19 Oct 2006 18:47:56 GMT

Hi,

It´s only 3 weeks since I started to work with a HCS12 family microcontroller (MC9S12C32+chipS12 demoboard) and I´m quite lost. I have been trying to make a program with interrupts, just a very simple one, which just waits for the RTI to be set before toggleing a led with it´s interrupt handler.

I have been reading a lot of stuff about that, but I don´t know if I have really understood it. What I have to do is (I´m programming with Imagecraft´s ICC12 compiler):

1- Define the interrupt handler in my c code file, like this

#pragma interrupt_handler timer_handler

...

                 void timer_handler()
                 {
                        ...
                  }

2- Modify my vectors.c file like this:

                #pragma abs_address:0xffd0

               /* change the above address if your vector starts elsewhere*/
                void (*interrupt_vectors[])(void) =
               {
                /* to cast a constant, say 0xb600, use (void (*)())0xb600*/
                /* 812A4 vectors starts at 0xff80, but most entries are not used if you use Key Wakeup H, change the start address to 0xffCE and add one entry to the beginning */

               DUMMY_ENTRY, /* BDLC */ /* Key Wakeup J */
                DUMMY_ENTRY, /* ATD */ /* ATD */
                DUMMY_ENTRY, /* RESERVED */ /* SCI 1 */
                DUMMY_ENTRY, /* SCI */
                DUMMY_ENTRY, /* SPI */
                DUMMY_ENTRY, /* PAIE */
                DUMMY_ENTRY, /* PAO */
                DUMMY_ENTRY, /* TOF */
                DUMMY_ENTRY, /* HC12 TC7 */
                DUMMY_ENTRY, /* TC6 */
                DUMMY_ENTRY, /* TC5 */
                DUMMY_ENTRY, /* TC4 */
                DUMMY_ENTRY, /* TC3 */
                DUMMY_ENTRY, /* TC2 */
                DUMMY_ENTRY, /* TC1 */
                DUMMY_ENTRY, /* TC0 */
                timer_handler,     /* RTI */
                DUMMY_ENTRY, /* IRQ */
                DUMMY_ENTRY, /* XIRQ */
                DUMMY_ENTRY, /* SWI */

               DUMMY_ENTRY, /* ILLOP */
                DUMMY_ENTRY, /* COP */
                DUMMY_ENTRY, /* CLM */
                _start /* RESET */
                };
#pragma end_abs_address

Can anyone tell me if I´m right? and what I have to do with the "vectors.c" file? should I include (#include vectors.c) in my c code?

If anyone could tell where I can find some C coded examples it would be great.

THX in advance

M3H0

Re: Newbie question about interrupts

J2MEJediMaster — Thu, 19 Oct 2006 23:11:07 GMT

This forum thread has a discussion about setting up interrupts. It also references one or two app notes that might provide source code for you to study.

---Tom

Re: Newbie question about interrupts

M3H0 — Fri, 20 Oct 2006 12:38:25 GMT

Thank you a lot, I will have a look to that thread

Oroitz

topic Re: Newbie question about interrupts in S12 / MagniV Microcontrollers

Newbie question about interrupts

Re: Newbie question about interrupts

Re: Newbie question about interrupts