topic Re: GPIO Interrupt on KL25Z works only with internal clock setup in Kinetis Microcontrollers

GPIO Interrupt on KL25Z works only with internal clock setup

pokemongoesar — Sat, 06 Jul 2019 17:48:03 GMT

I work with bear metal on the KL25z and I have read the last weak documentation and forum posts

about external Interrupt on the KLZ.

My problem is that the interrupt is only working with the Clock setup to PortA and toggles then the

Interrupt over and over again but it isn't working with an external source.

But I want to get an Interrupt if an external signal is incoming but if I comment out the Line:

SIM_SCGC5 |= SIM_SCGC5_PORTA_MASK;

I get the HardFault Stackframe at the declaration of PORTA_PCR17 :

Stack frame:
R0 = 0000031C
R1 = 40049000
R2 = E000E100
R3 = C0000000
R12 = 00000016
LR = 80008980
PC = 0000092E
PSR = 81000000
Misc
LR/EXC_RETURN= FFFFFFF9

My Code:

int main(int argc, char* argv[]) {
// Send a greeting to the trace device (skipped on Release).
trace_puts("Hello ARM World!");

    SIM_SCGC5 |= SIM_SCGC5_PORTA_MASK;
   __asm volatile("cpsie i");    //Enable Global Interrupts
   NVIC_SetPriority(PORTA_IRQn, (1UL << __NVIC_PRIO_BITS) - 1UL);
   PORTA_PCR17 |= PORT_PCR_MUX(1) | PORT_PCR_PE_MASK |

PORT_PCR_PS_MASK | PORT_PCR_IRQC(0x08); // Interrupt on rising and falling edge

NVIC_EnableIRQ(PORTA_IRQn); //Enable interrupt on IRQN
while (1) {}
}

extern "C" void
PORTA_IRQHandler() {
trace_puts("1");
trace_puts("2");
}

I hope someone can tell me the problem, I have no clue what I do wrong, I read so many docs and

I'm now done with my knowledge....

Greedings,

Max

Re: GPIO Interrupt on KL25Z works only with internal clock setup

pokemongoesar — Sun, 07 Jul 2019 14:26:44 GMT

I tested different IRQC Options and I found out that 'Interrupt when logic one - 1100' triggers directly, I think the pin might be pulled up internally and the option 'Interrupt when logic zero - 1000' works only one time after the first time i put in GND to initalize the interrupt it keeps running forever, even when I plug in 5V it keeps running and vice versa with the logic zero option.

I also tried 'NVIC_ClearPendingIRQ(PORTA_IRQn);' in the Interrupt but without any success.

Did anyone know what I missed in the Interrupt and Pin Setup?

Re: GPIO Interrupt on KL25Z works only with internal clock setup

mjbcswitzerland — Mon, 08 Jul 2019 18:42:04 GMT

You can't access PORTx_PCRy registers without them being clocked so a hard-fault in such a case is normal.

When your interrupt fires you must clear its pending flag by writing to PORTx_ISFR otherwise it will continuously re-enter.

Kinetis GPIO interrupt Video: https://www.youtube.com/watch?v=CubinvMuTwU

(also discussing sharing interrupt vectors for unrestricted operation)

Regards

Mark

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