STM32单片机学习(2) 外部中断

注：GPIO的复用功能必须打开，如红字部分

• 配置外部中断源并进行中断源和GPIO的连接

GPIO_EXTILineConfig(GPIO_PortSourceGPIOE, GPIO_PinSource0);
GPIO_EXTILineConfig(GPIO_PortSourceGPIOE, GPIO_PinSource1);
GPIO_EXTILineConfig(GPIO_PortSourceGPIOB, GPIO_PinSource8);
GPIO_EXTILineConfig(GPIO_PortSourceGPIOB, GPIO_PinSource9);

EXTI_InitStructure.EXTI_Line = EXTI_Line0|EXTI_Line1|EXTI_Line8|EXTI_Line9;
EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling;
EXTI_InitStructure.EXTI_LineCmd = ENABLE;
EXTI_Init(&EXTI_InitStructure);

• 编写相应中断源的中断处理程序

void EXTI0_IRQHandler(void)
{
if(Sys_Status > MIN_STATUS)
{
Sys_Status --;
}
EXTI_ClearITPendingBit(EXTI_Line0);
}

void EXTI1_IRQHandler(void)
{
PEout(2) = ~PEout(2);
EXTI_ClearITPendingBit(EXTI_Line1);
}

#define Exti_From_Pin8 0x00000100
#define Exti_From_Pin9 0x00000200

void EXTI9_5_IRQHandler(void)
{

u32 Temp = 0x00;

PEout(2) = ~PEout(2);
Temp = EXTI->PR; //取读是那个引脚的中断
switch(Temp)
{
case Exti_From_Pin8:
EXTI_ClearITPendingBit(EXTI_Line8);
break;
case Exti_From_Pin9:
if(Sys_Status < MAX_STATUS)
{
Sys_Status ++;
}
EXTI_ClearITPendingBit(EXTI_Line9);
break;
default:break;
}
}

==================================================================================

中断处理程序说明，由于外部中断EXTI5——EXTI9公用了一个中断（EXTI10——EXTI15类似）所以要

区分不同的中断源需要进行相应的判断。如上EXTI9_5_IRQHandler中，通过取读EXTI->PR寄存器来判

断中断的来源。