Kinetis MicrocontrollersのトピックRe: Return from ISR (PIT)

Return from ISR (PIT)

juanignaciotroi — Mon, 23 Feb 2015 20:05:13 GMT

Hello. I am giving my first steps on the KE02 and I have a problem. I have set up the PIT correctly using the processor expert. However, I cant get out de ISR. Once it finishes, it starts again. What should I do once mi ISR has finished to return to the main program? Thanks, Juan Ignacio Troisi

Re: Return from ISR (PIT)

adriancano — Mon, 23 Feb 2015 23:02:17 GMT

Hi,

I assume you are using the Init_PIT component and you are writing your own ISR code and not using the one generated by processor expert. Which component you are using?

It is probably that you are not clearing the interrupt flag. Try the next:

void PIT0_Isr( void )
{
    if( PIT_TFLG0 )
    {
        /* clear timer interrupt flag by writing 1*/
        PIT_TFLG0 = 0x01;   
}

Hope this information can help you

Best Regards,
Adrian Sanchez Cano
Technical Support Engineer
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Re: Return from ISR (PIT)

mjbcswitzerland — Mon, 23 Feb 2015 23:29:02 GMT

Hi Juan

Make sure that the PIT interrupt flag is reset by writing it with '1' to clear. Eg.

PIT_TFLG0 = PIT_TFLG_TIF;

Regards

Mark

Kinetis: µTasker Kinetis support

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Re: Return from ISR (PIT)

juanignaciotroi — Tue, 24 Feb 2015 13:36:01 GMT

Hello. A new problem come up now I tryied to create de whole interrupt. The following error come up: 'conflicting types for 'isr_display' '. Is there a library which i shlould have included before of something related with the isr? Thanks

void isr_display(unsigned int DISPC){


	DISPC++;

	if( DISPC == 5) DISPC = 0;

	int i;
	unsigned char byte; //variable auxiliar para hacer mascara con el numero binario

	for(i=0;i<8;i++){
	unsigned char bit = byte & 1; //hacemos mascara con 00000001b
	byte = byte >> 1; // rotamos el byte para hacer lo mismo el proximo ciclo

	if (bit == 0) Red_SetVal();
	else Red_ClrVal ();	//sacamos el bit como corresponda por el pin


	}

if( PIT_TFLG0 ) /* clear timer interrupt flag by writing 1*/

	PIT_TFLG0 = 0x01;
	}

Re: Return from ISR (PIT)

adriancano — Tue, 24 Feb 2015 17:05:04 GMT

Hi,

Are you using the Init_PIT component?

Regards,

Adrian

Re: Return from ISR (PIT)

ndavies — Tue, 24 Feb 2015 19:11:43 GMT

If Isr_display() is an interrupt service routine, you cannot pass in the DISPC variable. The ISR must be declared as void Isr_Display(). The ISR cannot be declared as void Isr_Display(unsigned int DISPC). DISPC must be declared as global to do what you want to do.

try this instead:

unsigned int DISPC = 0; // Make DISPC global

void isr_display()

{

DISPC++;

.......// insert the rest of the routine.

}

Norm