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How fast we can go with EXTI

Question asked by ahmed.waqar on May 12, 2015
Latest reply on May 12, 2015 by Clive One
I am using external interrupts. STM32F407 is not handling interrupt at speed of greater than 2MHz.

/* Includes ------------------------------------------------------------------*/
#include "stm32f4xx.h"
#include "stm32f4xx_syscfg.h"
#include "stm32f4xx_rcc.h"
#include "stm32f4xx_gpio.h"
#include "stm32f4xx_exti.h"
#include "misc.h"


EXTI_InitTypeDef   EXTI_InitStructure;
void EXTILine0_Config(void);
void LEDInit(void);

void main(void)
{
 LEDInit();
 EXTILine0_Config();
 EXTI_GenerateSWInterrupt(EXTI_Line0);

  while (1)
  {
  }
}

void LEDInit()
{
  GPIO_InitTypeDef  GPIO_InitStructure;
  RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOD, ENABLE);

  /* Configure the GPIO_LED pin */
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_15;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT;
  GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
  GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;
  GPIO_Init(GPIOD, &GPIO_InitStructure);
}

void EXTILine0_Config(void)
{

  GPIO_InitTypeDef   GPIO_InitStructure;
  NVIC_InitTypeDef   NVIC_InitStructure;

  /* Enable GPIOA clock */
  RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);
  /* Enable SYSCFG clock */
  RCC_APB2PeriphClockCmd(RCC_APB2Periph_SYSCFG, ENABLE);

  /* Configure PA0 pin as input floating */
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN;
  GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0;
  GPIO_Init(GPIOA, &GPIO_InitStructure);

  /* Connect EXTI Line0 to PA0 pin */
  SYSCFG_EXTILineConfig(EXTI_PortSourceGPIOA, EXTI_PinSource0);

  /* Configure EXTI Line0 */
  EXTI_InitStructure.EXTI_Line = EXTI_Line0;
  EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
  EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Rising;
  EXTI_InitStructure.EXTI_LineCmd = ENABLE;
  EXTI_Init(&EXTI_InitStructure);

  /* Enable and set EXTI Line0 Interrupt to the lowest priority */
  NVIC_InitStructure.NVIC_IRQChannel = EXTI0_IRQn;
  NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x01;
  NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x01;
  NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
  NVIC_Init(&NVIC_InitStructure);
}


void EXTI0_IRQHandler(void)
{
              if (((EXTI->PR & EXTI_Line0) != (uint32_t)RESET) && ((EXTI->IMR & EXTI_Line0) != (uint32_t)RESET))
             {
            GPIOD->ODR ^= 0x8000;
            EXTI->PR = 0x0001;
        }
}

Please help me!

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