按键中断代码编写
代码:
key_it.h
#ifndef __KEY_IT_H__
#define __KEY_IT_H__
#include "stm32mp1xx_gpio.h"
#include "stm32mp1xx_exti.h"
#include "stm32mp1xx_rcc.h"
#include "stm32mp1xx_gic.h"
void key1_it_config();
void key2_it_config();
void key3_it_config();
#endif
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;
}
void key3_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EXTI8事件
EXTI->EXTICR3 &= (~(0XFF << 0));
EXTI->EXTICR3 |= (0x05 << 0);
// 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 98/32=3...2
GICD->ISENABLER[3] |= (0x1 << 2);
// 7.设置98号中断优先级 98/4=24...2 2*8+3=19
GICD->IPRIORITYR[24] &= (~(0x1f << 19));
GICD->IPRIORITYR[24] |= (0x0 << 19);
// 8.设置98号中断可以被CPU0处理 98/4=24...2
GICD->ITARGETSR[24] &= (~(0x3 << 16));
GICD->ITARGETSR[24] |= (0x1 << 16);
//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;
}
do_irq.c
#include "key_it.h"
extern void printf(const char *fmt, ...);
unsigned int i = 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");
//清除exti中断标志位
EXTI->FPR1 |=(0x1 << 3);
//清除GICD中断标志位
GICD->ICPENDR[3] = (0x1 << 3);
break;
case 97:
printf("key2 int\n");
// 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;
case 98:
printf("key3 int\n");
// 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;
}
//清除IAR寄存器的值
GICC->EOIR = irqno;
}
main.c
#include "key_it.h"
//封装延时函数
void delay(int ms)
{
int i,j;
for(i=0;i<ms;i++)
{
for(j=0;j<2000;j++);
}
}
int main()
{
//中断初始化
key1_it_config();
key2_it_config();
key3_it_config();
//现象是发送一个a串口工具打印一个b
while(1)
{
printf("main func\n");
delay(2000);
}
return 0;
}
运行结果:
