K20 PIT ISR configuration problem

[yvesb]

Hi,

I am trying to configure an isr on the K20P100 dev kit (TWRK20D) to blink a LED, using the demo_gpio.c example as basis.

Here's my init routine called by main:

void _init_PIT()

{

   // enable PIT clock

    SIM_SCGC6 |= SIM_SCGC6_PIT_MASK;

   // enable PIT clock, freeze in debug

    PIT_MCR = 0x01;

   // set PIT 3

    PIT_LDVAL3 = 5000000; // setup timer for 5000000 cycles

    PIT_TCTRL3 = PIT_TCTRL_TIE_MASK // enable timer interrupt

                | PIT_TCTRL_TEN_MASK; // enable timer

     NVICICPR2 |= 1 << (71%32);

     NVICISER2 |= 1 << (71%32);

}

in the isr.h, I added this:

#undef  VECTOR_87

#define VECTOR_87 isr_pit3

extern void isr_pit3(void);

then I added in demo_gpio.c:

void isr_pit3(void)

{

    PIT_TFLG3 |= 1;

    GPIOC_PTOR |= 1<<PIN_LED_2; 

}

This code doesn't work, execution never goes to isr_pit3() function.

Am I missing something?

Regards,

Yves

[yvesb · Accepted solution]

The problem was that declarations in isr.h are ignored and must be written in vectors.h.

However, this doesn't explain why the isr from the example, not declared in vectors.h, worked!!

[yvesb]

Just noticed that if I use the debug terminal, it displays the following message:

****default_isr entered on vector 87*****

87 is the vector for PIT3. but I don't understand why this message is displayed