题目1：按键中断代码编写
代码：
main.c
#include "key_it.h"
#include "led.h"
void delay(int ms)
{
int i,j;
for(i=0;i<ms;i++)
{
for(j=0;j<2000;j++);
}
}
int main()
{
myall_led_init();
key1_it_config();
key2_it_config();
key3_it_config();
while(1)
{
printf("main func\n");
delay(2000);
}
return 0;
}key_it.c
#include "key_it.h"
void key1_it_config()
{
//1.设置GPIOF时钟使能
RCC->MP_AHB4ENSETR|=(0x1<<5);
//2.将PF9管脚设置为输入
GPIOF->MODER &=(~(0x3<<18));
// 3.设置由PF9产生EXTI9事件
EXTI->EXTICR3 &= (~(0XFF<<8));
EXTI->EXTICR3 |= (0X05<<8);
//4.设置EXTI9事件的检测方式为下降沿检测
EXTI->FTSR1 |= (0X1<<9);
//5.允许中断不屏蔽，可以被转发到GIC
EXTI->C1IMR1 |= (0X1<<9);
//6.允许EXTI9（99号）中断被保存在组0中
GICD->ISENABLER[3] |= (0X1<<3);
//7.设置99号中断优先级
GICD->IPRIORITYR[24] &= (~(0X1F<<27));
GICD->IPRIORITYR[24] |= (0X0<<27);
//8.设置99号中断可以被CPU0处理
GICD->ITARGETSR[24] &= (~(0x3<<24));
GICD->ITARGETSR[24] |= (0x1<<24);
//9.允许99号中断被转发到CPU接口层
GICD->CTRL |= 0x1;
//10.设置中断优先级掩码
GICC->PMR |=(0x1f<<3);
//11.允许中断被转发给CPU处理
GICC->CTRL |=0x1;
}
void key2_it_config()
{
//1.设置GPIOF时钟使能
RCC->MP_AHB4ENSETR|=(0x1<<5);
//2.将PF8管脚设置为输入
GPIOF->MODER &=(~(0x3<<16));
// 3.设置由PF8产生EXTI9事件
EXTI->EXTICR3 &= (~(0xff));
EXTI->EXTICR3 |=(0X05);
//4.设置EXTI8事件的检测方式为下降沿检测
EXTI->FTSR1 |= (0X1<<8);
//5.允许中断不屏蔽，可以被转发到GIC
EXTI->C1IMR1 |= (0X1<<8);
//6.允许EXTI8（98号）中断被保存在组0中
GICD->ISENABLER[3] |= (0X1<<2);
//7.设置98号中断优先级
GICD->IPRIORITYR[24] &= (~(0X1F<<19));
GICD->IPRIORITYR[24] |= (0X0<<19);
//8.设置98号中断可以被CPU0处理
GICD->ITARGETSR[24] &= (~(0x3<<16));
GICD->ITARGETSR[24] |= (0x1<<16);
//9.允许98号中断被转发到CPU接口层
GICD->CTRL |= 0x1;
//10.设置中断优先级掩码
GICC->PMR |=(0x1f<<3);
//11.允许中断被转发给CPU处理
GICC->CTRL |=0x1;
}
void key3_it_config()
{
//1.设置GPIOF时钟使能
RCC->MP_AHB4ENSETR|=(0x1<<5);
//2.将PF7管脚设置为输入
GPIOF->MODER &=(~(0x3<<14));
// 3.设置由PF7产生EXTI7事件
EXTI->EXTICR2 &= (~(0XFF<<24));
EXTI->EXTICR2 |= (0X05<<24);
//4.设置EXTI7事件的检测方式为下降沿检测
EXTI->FTSR1 |= (0X1<<7);
//5.允许中断不屏蔽，可以被转发到GIC
EXTI->C1IMR1 |= (0X1<<7);
//6.允许EXTI7（97号）中断被保存在组0中
GICD->ISENABLER[3] |= (0X1<<1);
//7.设置97号中断优先级
GICD->IPRIORITYR[24] &= (~(0X1F<<11));
GICD->IPRIORITYR[24] |= (0X0<<11);
//8.设置97号中断可以被CPU0处理
GICD->ITARGETSR[24] &= (~(0x3<<8));
GICD->ITARGETSR[24] |= (0x1<<8);
//9.允许97号中断被转发到CPU接口层
GICD->CTRL |= 0x1;
//10.设置中断优先级掩码
GICC->PMR |=(0x1f<<3);
//11.允许中断被转发给CPU处理
GICC->CTRL |=0x1;
}key_it.h
#ifndef __KEY_IT_H__
#define __KEY_IT_H__
#include "stm32mp1xx_gpio.h"
#include "stm32mp1xx_rcc.h"
#include "stm32mp1xx_gic.h"
#include "stm32mp1xx_exti.h"
extern void printf(const char *fmt, ...);
void key1_it_config();
void key2_it_config();
void key3_it_config();
#endifdo_irq.c
#include"key_it.h"
#include "led.h"
extern void printf(const char *fmt, ...);
unsigned int i = 0;
int flag1=0,flag2=0,flag3=0;
void do_irq(void)
{
//获取中断号，根据中断号的不同进行不同的中断处理
int irqno;
irqno=GICC->IAR&0x3ff;
switch(irqno)
{
case 99:
printf("key1 int\n");
if(flag1%2==0){
myled1_on();
flag1++;
}
else
{
flag1++;
myled1_off();
}
//清除exti中断标志位
EXTI->FPR1|=(0X1<<9);
//清除GICD中断标志位
GICD->ICPENDR[3] = (0x1 << 3);
break;
case 98:
printf("key2 int\n");
if(flag2%2==0){
myled2_on();
flag2++;
}
else
{
flag2++;
myled2_off();
}
//清除exti中断标志位
EXTI->FPR1|=(0X1<<8);
//清除GICD中断标志位
GICD->ICPENDR[3] = (0x1 << 2);
break;
case 97:
printf("key3 int\n");
if(flag3%2==0){
myled3_on();
flag3++;
}
else
{
flag3++;
myled3_off();
}
//清除exti中断标志位
EXTI->FPR1|=(0X1<<7);
//清除GICD中断标志位
GICD->ICPENDR[3] = (0x1 << 1);
break;
}
//清除IAR寄存器的值
GICC->EOIR = irqno;
}现象：
