/* Enable GPIOA clock */
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOА | RCC_APB2Periph_AFIO, ENABLE);
   
       /* Configure PA7 as inpit - "FLOATING" mode */
    GPIO_StructInit(&GPIO_InitStructure);
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_7;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
    GPIO_Init(GPIOA, &GPIO_InitStructure);
   
   GPIO_EXTILineConfig(GPIO_PortSourceGPIOA, GPIO_PinSource7);
   
    EXTI_StructInit(&EXTI_InitStructure);
    EXTI_InitStructure.EXTI_Line = EXTI_Line7;
    EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
    EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling;
//    EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Rising;
    EXTI_InitStructure.EXTI_LineCmd = ENABLE;
    EXTI_Init(&EXTI_InitStructure);

    EXTI_ClearITPendingBit(EXTI_Line7);

    NVIC_InitStructure.NVIC_IRQChannel = EXTI9_5_IRQn;
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority    =    0x0F;
    NVIC_InitStructure.NVIC_IRQChannelSubPriority          =    0x0F;
    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
    NVIC_Init(&NVIC_InitStructure);
   
   
   .
   .
   .
   
   
void EXTI9_5_IRQHandler(void)
{

     if(EXTI_GetITStatus(EXTI_Line7) != RESET)
     {

       /* Clear the Key Button EXTI line pending bit */
        EXTI_ClearITPendingBit(EXTI_Line7);
     }
}   

     /* Enable GPIOB clock */
     RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOB, ENABLE);
     /* Configure PB1 pin as input floating */
     GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN;
     GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
     GPIO_InitStructure.GPIO_Pin = GPIO_Pin_1;
     GPIO_Init(GPIOB, &GPIO_InitStructure);

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

     /* Connect EXTI1 Line to PB1 pin */
     SYSCFG_EXTILineConfig(EXTI_PortSourceGPIOB, EXTI_PinSource1);

     /* Configure EXTI1 line */
     EXTI_InitStructure.EXTI_Line = EXTI_Line1;
     EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
     EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling;
     EXTI_InitStructure.EXTI_LineCmd = ENABLE;
     EXTI_Init(&EXTI_InitStructure);

     /* Enable and set EXTI1 Interrupt to the lowest priority */
     NVIC_InitStructure.NVIC_IRQChannel = EXTI1_IRQn;
     NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x00;
     NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x0F;
     NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
     NVIC_Init(&NVIC_InitStructure);
    
    
     .
     .
     .
    
void EXTI1_IRQHandler(void)
{

   if(EXTI_GetITStatus(EXTI_Line1) != RESET)
   {
      // Clear the EXTI line 1 pending bit //
      EXTI_ClearITPendingBit(EXTI_Line1);


   }
}