stmf4 external interrupt

Posted on November 15, 2013 at 16:35

I have a rather simple problem. Just trying to run the external interrupt on pin PA0 on stmf4-discovery without the library functions. It ran correctly on simulation trial using stm32f103 device. But I'm missing out something in implementing this on stmf4-disc hardware. Can someone point out the mistake? Here is the piece of my code:

&sharpinclude <stdio.h>

&sharpinclude <stm32f4xx.h>

&sharpinclude ''LED.h''

extern void LED_Init (void);

extern void LED_On (unsigned int num);

extern void LED_Off (unsigned int num);

void button_init()

{

    RCC->AHB1ENR     |=  ((1UL << 0) );                 /* Enable GPIOA clock              */

    GPIOA->MODER = 0x00000000;

 GPIOA->PUPDR = 0x55555555;

}

void wait (void)  {

  int  d;

  for (d = 0; d < 200000; d++);             /* only to delay for LED flashes */

}

int main()

{

  SystemCoreClockUpdate();           /* Get Core Clock Frequency   */

    if (SysTick_Config(SystemCoreClock / 1000)) { /* SysTick 1 msec interrupts  */

      while (1);                               

    }

  LED_Init();

  button_init(); //BUtton on PA0

  EXTI->IMR |= (1UL<<0); // Enable not maskable interrupt on BIT1 

  EXTI->RTSR |= (1UL<<0); // Rising Edge

  //SYSCFG->EXTICR[0] &= ~BIT1; //  0000 for interrupt for PA[0]

  NVIC_EnableIRQ(6); 

  while(1)

{

  }

}

void EXTI0_IRQHandler(void)

{ 

  if(EXTI->PR & 1UL)

  {

    EXTI->PR |= 1; // Clear with Setting to BIT1

    LED_On(3);

  }  

}

With Thanks,

Tapabrata

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