标准库外部中断

同HAL库的外部中断，这里用按键来进行中断

void EXTI0_IRQHandler(void)
{
	delay_ms(10);	//消抖
	if(WK_UP==1)	//按键被按下 
	{
		//这里写在中断中执行的东西
	}		 
	 EXTI_ClearITPendingBit(EXTI_Line0); //清除LINE0上的中断标志位 
}	

由于中断是打断所在运行的程序，所以在中断中尽可能让程序运行的时间短一点，我个人在中断中只写变量（如状态，标识符）的改变，在其他函数中再对有关代码进行处理。

之后便可以对外部中断进行初始化

void EXTIX_Init(void)
{
	NVIC_InitTypeDef   NVIC_InitStructure;
	EXTI_InitTypeDef   EXTI_InitStructure;
	
	KEY_Init(); //按键对应的IO口初始化
 
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_SYSCFG, ENABLE);//使能SYSCFG时钟
	
 
	SYSCFG_EXTILineConfig(EXTI_PortSourceGPIOE, EXTI_PinSource2);//PE2 连接到中断线2
	SYSCFG_EXTILineConfig(EXTI_PortSourceGPIOE, EXTI_PinSource3);//PE3 连接到中断线3
	SYSCFG_EXTILineConfig(EXTI_PortSourceGPIOE, EXTI_PinSource4);//PE4 连接到中断线4
	SYSCFG_EXTILineConfig(EXTI_PortSourceGPIOA, EXTI_PinSource0);//PA0 连接到中断线0
	
  /* 配置EXTI_Line0 */
  EXTI_InitStructure.EXTI_Line = EXTI_Line0;//LINE0
  EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;//中断事件
  EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Rising; //上升沿触发 
  EXTI_InitStructure.EXTI_LineCmd = ENABLE;//使能LINE0
  EXTI_Init(&EXTI_InitStructure);//配置
	
	/* 配置EXTI_Line2,3,4 */
	EXTI_InitStructure.EXTI_Line = EXTI_Line2 | EXTI_Line3 | EXTI_Line4;
  EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;//中断事件
  EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling; //下降沿触发
  EXTI_InitStructure.EXTI_LineCmd = ENABLE;//中断线使能
  EXTI_Init(&EXTI_InitStructure);//配置
 
	NVIC_InitStructure.NVIC_IRQChannel = EXTI0_IRQn;//外部中断0
  NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x00;//抢占优先级0
  NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x02;//子优先级2
  NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;//使能外部中断通道
  NVIC_Init(&NVIC_InitStructure);//配置
	
	NVIC_InitStructure.NVIC_IRQChannel = EXTI2_IRQn;//外部中断2
  NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x03;//抢占优先级3
  NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x02;//子优先级2
  NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;//使能外部中断通道
  NVIC_Init(&NVIC_InitStructure);//配置
	
	
	NVIC_InitStructure.NVIC_IRQChannel = EXTI3_IRQn;//外部中断3
  NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x02;//抢占优先级2
  NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x02;//子优先级2
  NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;//使能外部中断通道
  NVIC_Init(&NVIC_InitStructure);//配置
	
	
	NVIC_InitStructure.NVIC_IRQChannel = EXTI4_IRQn;//外部中断4
  NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x01;//抢占优先级1
  NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x02;//子优先级2
  NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;//使能外部中断通道
  NVIC_Init(&NVIC_InitStructure);//配置
	   
}

关于中断的优先级又分为抢占优先级和子优先级，具体的可以看这一篇文章

【STM32】进阶（一）：抢占式优先级和响应式优先级（NVIC_PriorityGroupConfig）_stm32中断抢占优先级和响应优先级-优快云博客