本程序实现的功能：将GPIO.13端口设置成下降沿触发中断，当中断事件发生后，与GPIOD.8相连的LED变亮。

步骤：

① 配置要使用到的端口的时钟，输入输出以及端口的第二功能（这里的第二功能是指把端口配置成EXTI口）

 void GPIO_Configuration(void)
{

  /* Configure PC13 as input floating (EXTI Line13) */
  GPIO_InitTypeDef GPIO_InitStructure;
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_13;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
  GPIO_Init(GPIOC, &GPIO_InitStructure);

  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8 | GPIO_Pin_9 ;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
  GPIO_Init(GPIOD, &GPIO_InitStructure); 

}

②初始化EXTI_InitStructure结构体的各种需要的配置  

  /* Connect EXTI Line13 to PC.13 */
  GPIO_EXTILineConfig(GPIO_PortSourceGPIOC, GPIO_PinSource13);

  /* Configure EXTI Line13 to generate an interrupt on falling edge */  
  EXTI_InitStructure.EXTI_Line = EXTI_Line13;
  EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
  EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling;
  EXTI_InitStructure.EXTI_LineCmd = ENABLE;
  EXTI_Init(&EXTI_InitStructure);

  /* Generate software interrupt: simulate a falling edge applied on EXTI line 13 */
//  EXTI_GenerateSWInterrupt(EXTI_Line13);   //若使用此句，则不用手动触发中断事件，软件自动触发，继而直接转入中断处理函数。

 ③设置抢占式优先级和响应式优先级

void NVIC_Configuration(void)
{
  NVIC_InitTypeDef NVIC_InitStructure;
  
#ifdef  VECT_TAB_RAM  
  /* Set the Vector Table base location at 0x20000000 */ 
  NVIC_SetVectorTable(NVIC_VectTab_RAM, 0x0); 
#else  /* VECT_TAB_FLASH  */
  /* Set the Vector Table base location at 0x08000000 */ 
  NVIC_SetVectorTable(NVIC_VectTab_FLASH, 0x0);   
#endif

  /* Configure one bit for preemption priority */
  NVIC_PriorityGroupConfig(NVIC_PriorityGroup_1);
  
  /* Enable the EXTI15_10 Interrupt */
  NVIC_InitStructure.NVIC_IRQChannel = EXTI15_10_IRQChannel;
  NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
  NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
  NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
  NVIC_Init(&NVIC_InitStructure); 
}      

④ 在stm32f10x_it.c的EXTI15_10_IRQHandler中断函数里，完成中断处理程序。

void EXTI15_10_IRQHandler(void)
{
  if(EXTI_GetITStatus(EXTI_Line13)!=RESET)   
  {
    EXTI_ClearITPendingBit(EXTI_Line13);  //别忘记清除中断标志位哦！！！！
  GPIO_SetBits(GPIOD, GPIO_Pin_8 );
  GPIO_ResetBits(GPIOD, GPIO_Pin_9);
  }

}