STM32 外部中断_ 外部中断和事件

 

GPIO_InitTypeDef GPIO_InitStructure;

/* Enable GPIOD clock */
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOD, ENABLE);

 

/* Configure PD.03, PC.04, as input floating */
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_3 | GPIO_Pin_4 ;
     
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
GPIO_Init(GPIOD, &GPIO_InitStructure);

GPIO_EXTILineConfig(GPIO_PortSourceGPIOD, GPIO_PinSource3); //PD3作为外部中断引脚

/**
* @brief Selects the GPIO pin used as EXTI Line.
* @param GPIO_PortSource: selects the GPIO port to be used as source for EXTI lines.
*   This parameter can be GPIO_PortSourceGPIOx where x can be (A..G).
* @param GPIO_PinSource: specifies the EXTI line to be configured.
*   This parameter can be GPIO_PinSourcex where x can be (0..15).
* @retval None
*/
void GPIO_EXTILineConfig(uint8_t GPIO_PortSource, uint8_t GPIO_PinSource)

 

2.中断初始化

 

EXTI_InitTypeDef EXTI_InitStructure;

 

// Configure EXTI Line9 to generate an interrupt on falling edge 
EXTI_InitStructure.EXTI_Line = EXTI_Line3;
EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling;
EXTI_InitStructure.EXTI_LineCmd = ENABLE;
EXTI_Init(&EXTI_InitStructure);

GPIO_EXTILineConfig(GPIO_PortSourceGPIOD, GPIO_PinSource4);

// Configure EXTI Line9 to generate an interrupt on falling edge
EXTI_InitStructure.EXTI_Line = EXTI_Line4;
EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling;
EXTI_InitStructure.EXTI_LineCmd = ENABLE;
EXTI_Init(&EXTI_InitStructure);

 

3.在NVIC_Configuration 中Configures the NVIC and Vector Table base address.

/* Configure the Priority Group to 2 bits */
NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);

/* enabling interrupt */
NVIC_InitStructure.NVIC_IRQChannel=TIM2_IRQChannel;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);

/* Enable the EXTI3 Interrupt on PD.3 */
NVIC_InitStructure.NVIC_IRQChannel = EXTI3_IRQChannel;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 2;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);

    /* Enable the EXTI4 Interrupt on PD.4 */
NVIC_InitStructure.NVIC_IRQChannel = EXTI4_IRQChannel;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 2;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);

 

4.在stm32f0x_it.c 中写入 中断处理函数

 

/*******************************************************************************
* Function Name : EXTI3_IRQHandler
* Description    : This function handles External interrupt Line 3 request.
* Input          : None
* Output         : None
* Return         : None
*******************************************************************************/
void EXTI3_IRQHandler(void)
{
if(EXTI_GetITStatus(EXTI_Line3) != RESET)
{
   // Led_RW_ON();
    GPIO_SetBits(GPIOC, GPIO_Pin_4| GPIO_Pin_5 );
    
    
    /* Clear the EXTI line 9 pending bit */
    EXTI_ClearITPendingBit(EXTI_Line3);
}
}

/*******************************************************************************
* Function Name : EXTI4_IRQHandler
* Description    : This function handles External interrupt Line 4 request.
* Input          : None
* Output         : None
* Return         : None
*******************************************************************************/
void EXTI4_IRQHandler(void)
{
if(EXTI_GetITStatus(EXTI_Line4) != RESET)
{
    //Led_RW_OFF();
    GPIO_ResetBits(GPIOC, GPIO_Pin_4 | GPIO_Pin_5);
    /* Clear the EXTI line 9 pending bit */
    EXTI_ClearITPendingBit(EXTI_Line4);
}
}

=====================================================

 

STM32的“外部中断”和“事件”怎么理解?

事件是中断的触发源，开放了对应的中断屏蔽位，则事件可以触发相应的中断。 

事件还是其它一些操作的触发源，比如DMA，还有TIM中影子寄存器的传递与更新；而中断是不能触发这些操作的，所以要把事件与中断区分开。

 

参考下图：当你只要产生中断而不想触发其它操作时，就可以用事件屏蔽寄存器实现。