STM32外部中断

#include <stm32f10x.h>

void GPIO_Config(void);
void NVIC_Config(void);
void EXTI_Config(void);

int main(void)
{
    GPIO_Config();
    NVIC_Config();
    EXTI_Config();
    
    while(1)；
}

void GPIO_Config(void)
{
    /*定义一个GPIO_InitTypeDef类型的结构体，本类型在stm32f10x_gpio.h中定义*/
    GPIO_InitTypeDef GPIO_InitStructure;
    
    /*使能GPIOC和GPIOD时钟*/
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOG|RCC_APB2Periph_GPIOD, ENABLE);
    
    /*配置PC9管教作为推挽输出*/
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_14;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
    GPIO_Init(GPIOG, &GPIO_InitStructure);
    
    /*配置PD3作为浮空输入，为外部中断做准备*/
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_3;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
    GPIO_Init(GPIOD, &GPIO_InitStructure);
}

void EXTI_Config(void)
{
    /*定义一个EXTI_InitTypeDef类型的结构体，该类型在stm32f10x_exti.h中定义*/
    EXTI_InitTypeDef EXTI_InitStructure;
    
    /*使能AFIO时钟*/
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO,ENABLE);
    
    /*配置PD3管教作为EXTI线3*/
    GPIO_EXTILineConfig(GPIO_PortSourceGPIOD, GPIO_PinSource3);
    
    /*在EXTI中配置EXTI线3为中断模式，下降沿有效，并使能该配置*/
    EXTI_InitStructure.EXTI_Line = EXTI_Line3;
    EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
    EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Rising_Falling;
    EXTI_InitStructure.EXTI_LineCmd = ENABLE;
    EXTI_Init(&EXTI_InitStructure);
}

void NVIC_Config(void)
{
    /*定义一个NVIC_InitTypeDef类型的结构体，该类型在misc.h中定义*/
    NVIC_InitTypeDef NVIC_InitStructure;
    
    /*在NVIC中配置中断通道为EXTI3，抢占优先级为7，从优先级为7，并使能该中断*/
    NVIC_InitStructure.NVIC_IRQChannel = EXTI3_IRQn;
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x07;
    NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x07;
    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
    NVIC_Init(&NVIC_InitStructure);
}

/*声明变量LED*/
uint8_t led = 1;
/*EXTI3中断服务函数*/
void EXTI3_IRQHandler(void)
{
    /*检测EXTI3是否有效*/
    if(EXTI_GetITStatus(EXTI_Line3) == SET)
    {
        /*状态翻转*/
        led = ~led;
        
        /*如果等于1则PC9置位，否则清零*/
        if(led == 1)
        {
            GPIO_SetBits(GPIOG, GPIO_Pin_14);
        }
        else
        {
            GPIO_ResetBits(GPIOG, GPIO_Pin_14);
        }
        /*清除EXTI3的悬起标志位*/
        EXTI_ClearITPendingBit(EXTI_Line3);
    }
}