思路：按键->EXTI->GIC->CPU->异常向量表

//使能GPIOF时钟

//设置PF9管脚为输入(KEY1)

//设置PF9作为EXTI9事件的输入(事件编号对应管脚号)

//设置下降沿使能检测EXTI9事件 (也可设置上升沿没有下降沿严谨方便,不同场景不同选择)

//设置EXTI9事件不屏蔽   (只有不屏蔽中断事件才能继续执行)

//GICD使能EXTI9（99号）中断  (给中断信号使能)

//GICD 设置99号中断的优先级   (中断信号的优先级要设置的高)

//选择CPU0处理当前中断

//全局使能组0中断被转发到GICC  (在组0  组1 选择 组0)

//设置中断的优先级掩码  （让掩码的优先级降到最低，使自己的中断优先级高于他）

//允许组0中断被CPU处理

irq就是IRQ中断

key_it.h

#ifndef __KEY_IT_H__
#define __KEY_IT_H__
#include"stm32mp1xx_gpio.h"
#include"stm32mp1xx_gic.h"
#include"stm32mp1xx_exti.h"
#include"stm32mp1xx_rcc.h"
#include "led.h"
void key1_it_config();
void key2_it_config();
void key3_it_config();
void delay(int ms);
#endif

key_it.c

#include"key_it.h"
void key1_it_config()
{//使能GPIOF时钟RCC->MP_AHB4ENSETR |= (0x1<<5);//设置PF9管脚为输入GPIOF->MODER &= (~(0x3<<18));//设置PF9作为EXTI9事件的输入EXTI->EXTICR3 &= (~(0x1f<<8));EXTI->EXTICR3 |= (0x05<<8);//设置下降沿使能检测EXTI9事件EXTI->FTSR1 |= (0x1<<9);//设置EXTI9事件不屏蔽EXTI->C1IMR1 |= (0x1<<9);//GICD使能EXTI9（99号）中断GICD->ISENABLER[3] |= (0x1<<3);//GICD 设置99号中断的优先级GICD->IPRIORITYR[24] &= (~(0x1f<<27));//选择CPU0处理当前中断GICD->ITARGETSR[24] |= (0x1<<24);//全局使能组0中断被转发到GICCGICD->CTRL |= (0X1);//设置中断的优先级掩码GICC->PMR |= (0x1f<<3);//允许组0中断被CPU处理GICC->CTRL |= (0x1);
}
void key2_it_config()
{//使能GPIOF时钟RCC->MP_AHB4ENSETR |= (0x1<<5);//设置PF7管脚为输入GPIOF->MODER &= (~(0x3<<14));//设置PF7作为EXTI7事件的输入EXTI->EXTICR2 &= (~(0x1f<<24));EXTI->EXTICR2 |= (0x05<<24);//设置下降沿使能检测EXTI7事件EXTI->FTSR1 |= (0x1<<7);//设置EXTI7事件不屏蔽EXTI->C1IMR1 |= (0x1<<7);//GICD使能EXTI7（97号）中断GICD->ISENABLER[3] |= (0x1<<1);//GICD 设置97号中断的优先级GICD->IPRIORITYR[24] &= (~(0x1f<<11));//选择CPU0处理当前中断GICD->ITARGETSR[24] |= (0x1<<8);//全局使能组0中断被转发到GICCGICD->CTRL |= (0X1);//设置中断的优先级掩码GICC->PMR |= (0x1f<<3);//允许组0中断被CPU处理GICC->CTRL |= (0x1);
}
void key3_it_config()
{//使能GPIOF时钟RCC->MP_AHB4ENSETR |= (0x1<<5);//设置PF8管脚为输入GPIOF->MODER &= (~(0x3<<16));//设置PF8作为EXTI8事件的输入EXTI->EXTICR3 &= (~(0x1f));EXTI->EXTICR3 |= (0x05);//设置下降沿使能检测EXTI8事件EXTI->FTSR1 |= (0x1<<8);//设置EXTI8事件不屏蔽EXTI->C1IMR1 |= (0x1<<8);//GICD使能EXTI8（98号）中断GICD->ISENABLER[3] |= (0x1<<2);//GICD 设置98号中断的优先级GICD->IPRIORITYR[24] &= (~(0x1f<<19));//选择CPU0处理当前中断GICD->ITARGETSR[24] |= (0x1<<16);//全局使能组0中断被转发到GICCGICD->CTRL |= (0X1);//设置中断的优先级掩码GICC->PMR |= (0x1f<<3);//允许组0中断被CPU处理GICC->CTRL |= (0x1); 
}

do_irq.c

#include "key_it.h"
extern void printf(const char *fmt, ...);
unsigned int i = 0;//延时函数
void delay(int ms)
{int i,j;for(i=0;i<ms;i++){for(j=0;j<2000;j++);}
}void do_irq(void)
{//LED灯初始化all_led_init();int irqno = (GICC->IAR & 0x3ff);switch (irqno){case 99: // key1printf("KEY1_INT\n");//点亮两个灯led1_on();led3_on();delay(1000);//熄灭两个灯led1_off();led3_off();delay(1000);// 清除GICD的中断排队标志GICD->ICPENDR[3] |= (0x1<<3);// 清除exti的事件触发标志EXTI->FPR1 |= (0x1<<9);break;case 97: // KEY2printf("KEY2_INT\n");//点亮一个灯led1_on();delay(1000);//熄灭三个灯led1_off();led2_off();led3_off();delay(1000);// 清除GICD的中断排队标志GICD->ICPENDR[3] |= (0x1<<1);// 清除exti的事件触发标志EXTI->FPR1 |= (0x1<<7);break;case 98: // key3printf("KEY3_INT\n");//延时点亮三个灯，一个灯亮的同时下个灯灭led1_on();delay(1000);led1_off();led2_on();delay(1000);led2_off();led3_on();delay(1000);led3_off();// 清除GICD的中断排队标志GICD->ICPENDR[3] |= (0x1<<2);// 清除exti的事件触发标志EXTI->FPR1 |= (0x1<<8);break;}// 清除中断号GICC->EOIR = irqno;
}

main.c

#include "key_it.h"void delay(int ms)
{int i,j;for(i=0;i<ms;i++){for(j=0;j<2000;j++);}
}int main()
{key1_it_config();key2_it_config();key3_it_config();while (1){printf("do main...\n");delay(1000);}
}