作业

实验现象，主函数每一秒循环字符m，当按下按键1，则串口输出1，按下按键2，串口输出2，按下按键3，串口输出3

main.c

#include "uart4.h"

#include "led.h"

#include "key_in.h"
int main()

{



 	uart4_init();

	all_led_init();

	key1_init();

	key2_init();

	key3_init();	
    
    while(1)

	{

		putchar('m');

		delay(1000);

	}



	return 0;

}

do_irq.c

#include "stm32mp1xx_gic.h"
#include "stm32mp1xx_exti.h"
#include "uart4.h"
extern void printf(const char *fmt, ...);
unsigned int i = 0;
void do_irq(void) 
{
  uart4_init();
  unsigned int irqno=GICC->IAR&0x3ff;

  switch(irqno)
  {
    case 99:
    putchar('1');
    GICD->ICPENDR[3] |=(0x1<<3);
    EXTI->FPR1 |=(0x1<<9);
    break;
    
    case 97:
    putchar('2');
    GICD->ICPENDR[3] |=(0x1<<1);
    EXTI->FPR1 |=(0x1<<7);
    break;
    
    case 98:
    putchar('3');
    GICD->ICPENDR[3] |=(0x1<<2);
    EXTI->FPR1 |=(0x1<<8);
    break;
    
    
    default:
    break;

  }
  GICC->EOIR |=irqno;


}

key_in.c

#include "key_in.h"

void key1_init()
{
  //使能GPIOF外设时钟
  RCC->MP_AHB4ENSETR |=(0x1<< 5);

  //将pf9设为输出模式
  GPIOF->MODER &=(~(0x3<<18));
  

  //设置pf9管脚产生exti9事件
  EXTI->EXTICR3 &=(~(0xff<<8));
  EXTI->EXTICR3  |=(0x05<<8);
  //通过下降沿判断事件9是否产生
  EXTI->FTSR1 |=(0x1<<9);

  //取消exti9中断屏蔽
  EXTI->C1IMR1 |=(0x1<<9);

  //设置exti9全局中断使能
  GICD->ISENABLER[3] |=(0x1<<3);

  //设置中断优先级
  GICD->IPRIORITYR[24] &=(~(0x1f<<27));

  //设置cpu0处理中断
  GICD->ITARGETSR[24] |=(0x1<<24);

  //设置组0中断可以发送到GICC层
  GICD->CTRL |=(0x1);

  //设置中断优先级掩码
  GICC->PMR |= (0x1f<<3);

  //设置组0中断交给指定处理器处理
  GICC->CTRL |=0x1;

}

void key2_init()
{
   //使能GPIOF外设时钟
  RCC->MP_AHB4ENSETR |=(0x1<< 5);

  //将pf7设为输出模式
  GPIOF->MODER &=(~(0x3<<14));
  

  //设置pf7管脚产生exti7事件
  EXTI->EXTICR2 &=(~(0xff<<24));
  EXTI->EXTICR2  |=(0x05<<24);
  //通过下降沿判断事件7是否产生
  EXTI->FTSR1 |=(0x1<<7);

  //取消exti7中断屏蔽
  EXTI->C1IMR1 |=(0x1<<7);

  //设置exti7全局中断使能
  GICD->ISENABLER[3] |=(0x1<<1);

  //设置中断优先级
  GICD->IPRIORITYR[24] &=(~(0x1f<<11));

  //设置cpu0处理中断
  GICD->ITARGETSR[24] |=(0x1<<8);

  //设置组0中断可以发送到GICC层
  GICD->CTRL |=(0x1);

  //设置中断优先级掩码
  GICC->PMR |= (0x1f<<3);

  //设置组0中断交给指定处理器处理
  GICC->CTRL |=0x1;
}

void key3_init()
{
   //使能GPIOF外设时钟
  RCC->MP_AHB4ENSETR |=(0x1<< 5);

  //将pf8设为输出模式
  GPIOF->MODER &=(~(0x3<<16));
  

  //设置pf8管脚产生exti8事件
  EXTI->EXTICR3 &=(~(0xff));
  EXTI->EXTICR3  |=(0x05);
  //通过下降沿判断事件8是否产生
  EXTI->FTSR1 |=(0x1<<8);

  //取消exti8中断屏蔽
  EXTI->C1IMR1 |=(0x1<<8);

  //设置exti8全局中断使能
  GICD->ISENABLER[3] |=(0x1<<2);

  //设置中断优先级
  GICD->IPRIORITYR[24] &=(~(0x1f<<19));

  //设置cpu0处理中断
  GICD->ITARGETSR[24] |=(0x1<<16);

  //设置组0中断可以发送到GICC层
  GICD->CTRL |=(0x1);

  //设置中断优先级掩码
  GICC->PMR |= (0x1f<<3);

  //设置组0中断交给指定处理器处理
  GICC->CTRL |=0x1;
}