ARM:作业3

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: