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        STM32 外部中斷_ 外部中斷和事件

        作者: 時間:2016-11-13 來源:網(wǎng)絡 收藏
        1.GPIO 的正確設置
        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作為外部中斷引腳

        本文引用地址:http://www.104case.com/article/201611/316399.htm

        /**
        * @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.中斷初始化
        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 中寫入 中斷處理函數(shù)
        /*******************************************************************************
        * 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“外部中斷”和“事件”怎么理解?

        事件是中斷的觸發(fā)源,開放了對應的中斷屏蔽位,則事件可以觸發(fā)相應的中斷。

        事件還是其它一些操作的觸發(fā)源,比如DMA,還有TIM中影子寄存器的傳遞與更新;而中斷是不能觸發(fā)這些操作的,所以要把事件與中斷區(qū)分開。

        參考下圖:當你只要產(chǎn)生中斷而不想觸發(fā)其它操作時,就可以用事件屏蔽寄存器實現(xiàn)。




        關鍵詞: STM32外部中

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