实现开发板上三个按键按下后触发中断，控制LED灯的亮灭。

【本次实验现象为：按键1（key1）控制开灯，key3控制关灯，key2按下LED灯闪烁五次】

代码：

头文件mykey.h:

#ifndef __MYKEY_H__
#define __MYKEY_H__
#include "stm32mp1xx_exti.h" 
#include "stm32mp1xx_gic.h" 
#include "stm32mp1xx_gpio.h"
#include "stm32mp1xx_rcc.h" 
void key1_init_config();
void key2_init_config();
void key3_init_config(); 
void led_inited();#endif

主程序main.c:

#include "mykey.h"void delay_ms(int ms){int i,j;for(i=0;i<ms;i++){for(j=0;j<2000;j++){}}}int main(){//按键中断初始化key1_init_config();key2_init_config();key3_init_config();//LED灯初始化led_inited();//不让程序结束（本次实验等待按键按下触发中断）while (1){}return 0;}

封装初始化函数mykey.c:

#include "mykey.h"void key1_init_config()
{//使能GPIOF外设时钟RCC->MP_AHB4ENSETR |= (0X1<<5);//设置PF9为输入GPIOF->MODER &= (~(0X3<<18));//设置PF9产生EXTI9事件EXTI->EXTICR3 &= (~(0XFF<<8));EXTI->EXTICR3 |= (0X05<<8);//设置下降沿检测EXTI9事件EXTI->FTSR1 |= (0X1<<9);//取消EXTI9事件的屏蔽EXTI->C1IMR1 |= (0X1<<9);//全局使能99号中断GICD->ISENABLER[3]  |= (0X1<<3);//设置99号中断的优先级GICD->IPRIORITYR[24] &= (~(0X1F<<27));//最高优先级//设置99号中断的目标处理器//GICD->ITARGETSR[24] &= (~(0B11<<24));GICD->ITARGETSR[24] |= (0x1<<24);//允许组0中断被转发到GICC层GICD->CTRL |= 0X1;//设置中断优先级掩码GICC->PMR |= (0X1F<<3);//允许组0中断被转发给处理器GICC->CTRL |= 0x1;
}void key3_init_config()
{//使能GPIOF外设时钟RCC->MP_AHB4ENSETR |= (0X1<<5);//设置PF8为输入GPIOF->MODER &= (~(0X3<<16));//设置PF8产生EXTI8事件EXTI->EXTICR3 &= (~(0XFF));EXTI->EXTICR3 |= (0X05);//设置下降沿检测EXTI8事件EXTI->FTSR1 |= (0X1<<8);//取消EXTI8事件的屏蔽EXTI->C1IMR1 |= (0X1<<8);//全局使能98号中断GICD->ISENABLER[3]  |= (0X1<<2);//设置98号中断的优先级GICD->IPRIORITYR[24] &= (~(0X1F<<19));//最高优先级//设置98号中断的目标处理器//GICD->ITARGETSR[24] &= (~(0B11<<24));GICD->ITARGETSR[24] |= (0x1<<16);//允许组0中断被转发到GICC层GICD->CTRL |= 0X1;//设置中断优先级掩码GICC->PMR |= (0X1F<<3);//允许组0中断被转发给处理器GICC->CTRL |= 0x1;}void key2_init_config()
{//使能GPIOF外设时钟RCC->MP_AHB4ENSETR |= (0X1<<5);//设置PF7为输入GPIOF->MODER &= (~(0X3<<14));//设置PF7产生EXTI7事件EXTI->EXTICR2 &= (~(0XFF<<24));EXTI->EXTICR2 |= (0X05<<24);//设置下降沿检测EXTI7事件EXTI->FTSR1 |= (0X1<<7);//取消EXTI7事件的屏蔽EXTI->C1IMR1 |= (0X1<<7);//全局使能97号中断GICD->ISENABLER[3]  |= (0X1<<1);//设置97号中断的优先级GICD->IPRIORITYR[24] &= (~(0X1F<<11));//最高优先级//设置97号中断的目标处理器//GICD->ITARGETSR[24] &= (~(0B11<<24));GICD->ITARGETSR[24] |= (0x1<<8);//允许组0中断被转发到GICC层GICD->CTRL |= 0X1;//设置中断优先级掩码GICC->PMR |= (0X1F<<3);//允许组0中断被转发给处理器GICC->CTRL |= 0x1;
}void led_inited()
{//使能GPIO的外设时钟RCC->MP_AHB4ENSETR |= (0x3<<4);//设置输出GPIOE->MODER &= (~(0x3<<20));GPIOE->MODER |=  (0x1<<20);GPIOF->MODER &= (~(0x3<<20));GPIOF->MODER |=  (0x1<<20);GPIOE->MODER &= (~(0x3<<16));GPIOE->MODER |=  (0x1<<16);//设置默认关闭状态GPIOE->ODR &= (~(0x1<<10));GPIOF->ODR &= (~(0x1<<10));GPIOE->ODR &= (~(0x1<<8));
}

中断处理函数 do_irq.c:

#include "mykey.h"extern void delay_ms(int ms);
extern void printf(const char *fmt, ...);
unsigned int i = 0;
void do_irq(void) 
{//获取中断号unsigned int irqno = (GICC->IAR&0X3FF);switch (irqno){case 99://中断处理逻辑//按键1开灯GPIOE->ODR |= (0x1<<10);GPIOF->ODR |= (0x1<<10);GPIOE->ODR |= (0x1<<8);//清除GICD中的中断标志GICD->ICPENDR[3] |= (0X1<<3);//清除EXTI的中断触发标志EXTI->FPR1 |= (0X1<<9);break;case 98://按键 3关灯GPIOE->ODR &= (~(0x1<<10));GPIOF->ODR &= (~(0x1<<10));GPIOE->ODR &= (~(0x1<<8));GICD->ICPENDR[3] |= (0X1<<2);EXTI->FPR1 |= (0X1<<8);break;case 97://按键2闪烁五次for(i=0;i<5;i++){GPIOE->ODR |= (0x1<<10);GPIOF->ODR |= (0x1<<10);GPIOE->ODR |= (0x1<<8);delay_ms(500);GPIOE->ODR &= (~(0x1<<10));GPIOF->ODR &= (~(0x1<<10));GPIOE->ODR &= (~(0x1<<8));delay_ms(500);}GICD->ICPENDR[3] |= (0X1<<1);EXTI->FPR1 |= (0X1<<7);break;default:break;}GICC->EOIR = irqno;}