PIT Interrupt

maratheapurv — Thu, 01 Aug 2019 06:51:04 GMT

I'm trying to write a program for the PIT module of the FRDM-KV31F board using MCUXPRESSO but the code gets stalled in the while loop.

Is this happening because I haven't provided an interrupt routine? What changes should I perform?

Thank you,

Apurv Marathe.

Re: PIT Interrupt

mjbcswitzerland — Thu, 01 Aug 2019 11:28:13 GMT

Your code doesn't use interrupts, it just polls the timeout flag

    while(!(PIT->CHANNEL[1].TFLG & PIT_TFLG_TIF_MASK))
    {
       PTD->PSOR |= 0x2;
    }
         PTD->PCOR |= 0x2;
    return 0 ;

It would also quit after the first period.

PTD->PSOR |= 0x2; should really be PTD->PSOR = 0x2;
and PTD->PCOR |= 0x2; PTD->PCOR = 0x2; although it will work as you have it.

To make it run forever you could do:

while (1 != 0) {

PTD->PSOR = 0x2;

while(!(PIT->CHANNEL[1].TFLG & PIT_TFLG_TIF_MASK)) {}

PTD->PCOR = 0x2;

PIT->CHANNEL[1].TFLG = PIT_TFLG_TIF_MASK; // clear flag

while(!(PIT->CHANNEL[1].TFLG & PIT_TFLG_TIF_MASK)) {}

PIT->CHANNEL[1].TFLG = PIT_TFLG_TIF_MASK; // clear flag

}
(or similar).

I think your main issue that stops it working is your line

PIT->MCR |= 0x0; //activate pit module

MCR has the value 0x00000002 (disabled) out of reset and to start it one does

PIT->MCR = 0x0; (and not PIT->MCR |= 0x0; since this has no effect)

Regards

Mark

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Re: PIT Interrupt

maratheapurv — Thu, 01 Aug 2019 11:56:28 GMT

Hello Mark,

Thank you so much for your help!! That was such a silly mistake.

Thank you once again,

Apurv.

topic PIT Interrupt in Kinetis Microcontrollers

PIT Interrupt

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Re: PIT Interrupt