把IO装备为 EXTI中止的过程：
1：使能EXTI Line时钟和第二功用时钟。
2：装备EXTI Line中止优先级（NVIC）
3：装备EXTI Line IO （哪个引脚，输入形式，初始化）
4：把引脚装备为EXTI Line的中止源（GPIO操作），装备IO口的作业形式
5：装备EXTI Line的作业形式。
==============================================================================
例如：
GPIO_InitTypeDef GPIO_InitStructure;
EXTI_InitTypeDef EXTI_InitStructure;
/* config the extiline(PB0) clock and AFIO clock 使能extiline IO时钟和第二功用时钟*/
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB | RCC_APB2Periph_AFIO,ENABLE);
/* config the NVIC(PB0) 装备extiline中止优先级*/
NVIC_Configuration();
/* EXTI line gpio config(PB0) 装备EXTI line gpio */
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPD; // 上拉输入
GPIO_Init(GPIOB, &GPIO_InitStructure);
/* EXTI line(PB0) mode config 选定IO EXTI的IO线和IO口的中止形式 */
GPIO_EXTILineConfig(GPIO_PortSourceGPIOB, GPIO_PinSource0); //选定PB0为中止源
EXTI_InitStructure.EXTI_Line = EXTI_Line0;//把PB0连接到EXTI_Line0中止线上
EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt; //中止形式
EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling; //下降沿中止
EXTI_InitStructure.EXTI_LineCmd = ENABLE;//使能外部中止
EXTI_Init(&EXTI_InitStructure); //初始化
/*
* 函数名：NVIC_Configuration
* 描绘 ：装备嵌套向量中止控制器NVIC
* 输入 ：无
* 输出 ：无
* 调用 ：内部调用
*/
static void NVIC_Configuration(void)
{
NVIC_InitTypeDef NVIC_InitStructure;
/* Configure one bit for preemption priority */
NVIC_PriorityGroupConfig(NVIC_PriorityGroup_1);
/* 装备P[A|B|C|D|E]0为中止源 */
NVIC_InitStructure.NVIC_IRQChannel = EXTI0_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
}
接下来要写中止函数了
在stm32f10x_it.c中编写中止服务函数
/* I/O线中止，中止线为PB0 */
void EXTI0_IRQHandler(void)
{
if(EXTI_GetITStatus(EXTI_Line0) != RESET) //保证是否产生了EXTI Line中止
{
// LED1 取反
GPIO_WriteBit(GPIOC, GPIO_Pin_3,
(BitAction)((1-GPIO_ReadOutputDataBit(GPIOC, GPIO_Pin_3))));
EXTI_ClearITPendingBit(EXTI_Line0); //铲除中止标志位
}
}
要注意的是在中止服务程序完结之后还要记住铲除中止标志位.
这儿要阐明一下中止的分陪
EXTI0
EXTI1
EXTI2
EXTI3
EXTI4
EXTI5-9
EXTI10-15
中止0-4是每个中止线各自用一个中止函数，5-9是共用一个中止函数，10-15共用一个中止函数。
关于中止服务函数的命名的编写办法是：
在startup_stm32f10x_hd.s文件中查找外部中止源
; External Interrupts
DCD WWDG_IRQHandler ; Window Watchdog
DCD PVD_IRQHandler ; PVD through EXTI Line detect
DCD TAMPER_IRQHandler ; Tamper
DCD RTC_IRQHandler ; RTC
DCD FLASH_IRQHandler ; Flash
DCD RCC_IRQHandler ; RCC
DCD EXTI0_IRQHandler ; EXTI Line 0
DCD EXTI1_IRQHandler ; EXTI Line 1
DCD EXTI2_IRQHandler ; EXTI Line 2
DCD EXTI3_IRQHandler ; EXTI Line 3
DCD EXTI4_IRQHandler ; EXTI Line 4
DCD DMA1_Channel1_IRQHandler ; DMA1 Channel 1
DCD DMA1_Channel2_IRQHandler ; DMA1 Channel 2
DCD DMA1_Channel3_IRQHandler ; DMA1 Channel 3
DCD DMA1_Channel4_IRQHandler ; DMA1 Channel 4
DCD DMA1_Channel5_IRQHandler ; DMA1 Channel 5
DCD DMA1_Channel6_IRQHandler ; DMA1 Channel 6
DCD DMA1_Channel7_IRQHandler ; DMA1 Channel 7
DCD ADC1_2_IRQHandler ; ADC1 & ADC2
DCD USB_HP_CAN1_TX_IRQHandler ; USB High Priority or CAN1 TX
DCD USB_LP_CAN1_RX0_IRQHandler ; USB Low Priority or CAN1 RX0
DCD CAN1_RX1_IRQHandler ; CAN1 RX1
DCD CAN1_SCE_IRQHandler ; CAN1 SCE
DCD EXTI9_5_IRQHandler ; EXTI Line 9..5
DCD TIM1_BRK_IRQHandler ; TIM1 Break
DCD TIM1_UP_IRQHandler ; TIM1 Update
DCD TIM1_TRG_COM_IRQHandler ; TIM1 Trigger and Commutation
DCD TIM1_CC_IRQHandler ; TIM1 Capture Compare
DCD TIM2_IRQHandler ; TIM2
DCD TIM3_IRQHandler ; TIM3
DCD TIM4_IRQHandler ; TIM4
DCD I2C1_EV_IRQHandler ; I2C1 Event
DCD I2C1_ER_IRQHandler ; I2C1 Error
DCD I2C2_EV_IRQHandler ; I2C2 Event
DCD I2C2_ER_IRQHandler ; I2C2 Error
DCD SPI1_IRQHandler ; SPI1
DCD SPI2_IRQHandler ; SPI2
DCD USART1_IRQHandler ; USART1
DCD USART2_IRQHandler ; USART2
DCD USART3_IRQHandler ; USART3
DCD EXTI15_10_IRQHandler ; EXTI Line 15..10
DCD RTCAlarm_IRQHandler ; RTC Alarm through EXTI Line
DCD USBWakeUp_IRQHandler ; USB Wakeup from suspend
DCD TIM8_BRK_IRQHandler ; TIM8 Break
DCD TIM8_UP_IRQHandler ; TIM8 Update
DCD TIM8_TRG_COM_IRQHandler ; TIM8 Trigger and Commutation
DCD TIM8_CC_IRQHandler ; TIM8 Capture Compare
DCD ADC3_IRQHandler ; ADC3
DCD FSMC_IRQHandler ; FSMC
DCD SDIO_IRQHandler ; SDIO
DCD TIM5_IRQHandler ; TIM5
DCD SPI3_IRQHandler ; SPI3
DCD UART4_IRQHandler ; UART4
DCD UART5_IRQHandler ; UART5
DCD TIM6_IRQHandler ; TIM6
DCD TIM7_IRQHandler ; TIM7
DCD DMA2_Channel1_IRQHandler ; DMA2 Channel1
DCD DMA2_Channel2_IRQHandler ; DMA2 Channel2
DCD DMA2_Channel3_IRQHandler ; DMA2 Channel3
DCD DMA2_Channel4_5_IRQHandler ; DMA2 Channel4 & Channel5
============================================================================
void GPIO_EXTILineConfig(uint8_t GPIO_PortSource, uint8_t GPIO_PinSource)
把IO引脚装备为 EXTI Line，把IO引脚作为EXTI中止线运用，是IO的第二功用。
GPIO_EXTILineConfig(GPIO_PortSourceGPIOB, GPIO_PinSource0); //选定PB0为中止源(中止线)
==============================================================================
获取中止线的状况
ITStatus EXTI_GetITStatus(uint32_t EXTI_Line)
例如：
if(EXTI_GetITStatus(EXTI_Line0) != RESET) //保证是否产生了EXTI Line中止，也能够不加这条if句子（自己的了解）
{
// LED1 取反
GPIO_WriteBit(GPIOC, GPIO_Pin_3,(BitAction)((1-GPIO_ReadOutputDataBit(GPIOC, GPIO_Pin_3))));
EXTI_ClearITPendingBit(EXTI_Line0); //铲除中止标志位
}
============================================================================================
void EXTI_ClearITPendingBit(uint32_t EXTI_Line)
例如：
EXTI_ClearITPendingBit(EXTI_Line0); //铲除中止标志位 Clears the EXTI line pending bits. 清EXTI Line0的中止标志位。
