AnsweredAssumed Answered

STM32F4 discovery External interrupts not working

Question asked by chenna_reddy.sankhar on Feb 6, 2014
Latest reply on Feb 6, 2014 by Clive One
I wrote a code to generate rising edge interrupts for a 4MHz clock input to the board. The 4MHz input is generated by MCO while the core is pushed to 168MHz. 
I found that certain interrupts are not being tacked at all and when they are tackled, there are delays often (but not always) for the Microcontroller to enter ISR.

I am simply toggling external pin in the ISR

MAIN.C__________________________________________________________
int main(void)
{
  RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOD|RCC_AHB1Periph_GPIOA|RCC_AHB1Periph_GPIOC, ENABLE);
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT;
  GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;
  GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
  GPIO_Init(GPIOC, &GPIO_InitStructure);


      GPIO_InitStructure.GPIO_Pin =  GPIO_Pin_8;
      GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;
      GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
      GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
      GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
      GPIO_Init(GPIOA, &GPIO_InitStructure);
      GPIO_PinAFConfig(GPIOA, GPIO_Pin_8, GPIO_AF_MCO);
      RCC_MCO1Config(RCC_MCO1Source_HSE,RCC_MCO1Div_2); 
      EXTILine1_Config( );
  while (1);
}
void MCO_CLK_CONFIG(void){
     RCC_HSEConfig(RCC_HSE_ON);
     while(!RCC_WaitForHSEStartUp())
     {
     }
}
void EXTILine1_Config(void)
{
  /* Enable SYSCFG clock */
  RCC_APB2PeriphClockCmd(RCC_APB2Periph_SYSCFG, ENABLE);

  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN;
  GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_1;
  GPIO_Init(GPIOA, &GPIO_InitStructure);

  SYSCFG_EXTILineConfig(EXTI_PortSourceGPIOA, EXTI_PinSource1);

  EXTI_InitStructure.EXTI_Line = EXTI_Line1;
  EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
  EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Rising_Falling;
  EXTI_InitStructure.EXTI_LineCmd = ENABLE;
  EXTI_Init(&EXTI_InitStructure);

  NVIC_InitStructure.NVIC_IRQChannel = EXTI1_IRQn;
  NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x00;
  NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x00;
  NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
  NVIC_Init(&NVIC_InitStructure);
}

ISR________________________________________________________________________________________________ISR

void EXTI1_IRQHandler(void)
{
  if(EXTI_GetITStatus(EXTI_Line1) != RESET)
  {
       GPIOC->BSRRL = GPIO_Pin_9;
       GPIOC->BSRRH = GPIO_Pin_9;
       EXTI_ClearITPendingBit(EXTI_Line1);
}
}

Following is the image on Logic analyzer we captured.

INtpts.png


Can someone enlighten me regarding what the issue can be?
Thank you

Outcomes