key_it.c

#include"key_it.h"
void led_init()
{
    // 设置GPIOE/GPIOF时钟使能
    RCC->MP_AHB4ENSETR |= (0x3 << 4);
    // 设置PE10/PE8/PF10为输出模式
    GPIOE->MODER &= (~(0x3 << 20));
    GPIOE->MODER |= (0x1 << 20);
    GPIOE->MODER &= (~(0x3 << 16));
    GPIOE->MODER |= (0x1 << 16);
    GPIOF->MODER &= (~(0x3 << 20));
    GPIOF->MODER |= (0x1 << 20);
    // 设置PE10/PE8/PF10为推挽输出
    GPIOE->OTYPER &= (~(0x1 << 10));
    GPIOE->OTYPER &= (~(0X1 << 8));
    GPIOF->OTYPER &= (~(0x1 << 10));
    // 设置PE10/PE8/PF10输出速度为低速
    GPIOE->OSPEEDR &= (~(0x3 << 20));
    GPIOE->OSPEEDR &= (~(0X3 << 16));
    GPIOF->OSPEEDR &= (~(0x3 << 20));
    // 设置PE10/PE8/PF10无上拉下拉
    GPIOE->PUPDR &= (~(0x3 << 20));
    GPIOE->PUPDR &= (~(0X3 << 16));
    GPIOF->PUPDR &= (~(0X3 << 20));
}

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GICC
    GICD->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()
{
       //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GICC
    GICD->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()
{
      //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GICC
    GICD->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;
void do_irq(void) 
{
   int irqno = (GICC->IAR & 0x3ff);
    switch (irqno)
    {
    case 99: // key1
        printf("KEY1_INT\n");
          GPIOE->ODR |= (0x1<<10);
        // 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);
        delay(2000);
         GPIOE->ODR &= (~(0x1<<10));
        break;
    case 97: // KEY2
        printf("KEY2_INT\n");
         GPIOF->ODR |= (0x1<<10);
         // 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);
        delay(2000);
         GPIOF->ODR &= (~(0x1<<10));
        break;
    case 98: // key3
        printf("KEY3_INT\n");
         GPIOE->ODR |= (0x1<<8);
         // 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);
        delay(2000);
         GPIOE->ODR &= (~(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()

{

  led_init();

  key1_it_config();

  key2_it_config();

  key3_it_config();

    while (1)

    {

        printf("do main...\n");

        delay(1000);

    }

    return 0;

}