STM32 外部中斷_ 外部中斷和事件
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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
/**
* @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)
// 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);
// 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);
/* Configure the Priority Group to 2 bits */
NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);
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);
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);
* 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“外部中斷”和“事件”怎么理解?
事件是中斷的觸發(fā)源，開放了對應(yīng)的中斷屏蔽位，則事件可以觸發(fā)相應(yīng)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(dāng)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)。
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