STM32 外部中止_ 外部中止和事情

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作为外部中止引脚

/**
* @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.中止初始化

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 中止处理函数

/*******************************************************************************
* 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);
}
}

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STM32的“外部中止”和“事情”怎样了解?

事情是中止的触发源，开放了对应的中止屏蔽位，则事情能够触发相应的中止。

事情仍是其它一些操作的触发源，比方DMA，还有TIM中影子寄存器的传递与更新；而中止是不能触发这些操作的，所以要把事情与中止区分隔。

参阅下图：当你只需发生中止而不想触发其它操作时，就能够用事情屏蔽寄存器完成。