ARM开发（cortex-A7核中断实验)

1.实验目的：实现KEY1/LEY2/KE3三个按键，中断触发打印一句话，并且灯的状态取反；

key1 ----> LED3灯状态取反；

key2 ----> LED2灯状态取反；

key3 ----> LED1灯状态取反；

2.分析框图:

3.代码：

---key.h头文件---

#ifndef __KEY_H__
#define __KEY_H__

#include "stm32mp1xx_rcc.h"
#include "stm32mp1xx_gpio.h"
#include "stm32mp1xx_gic.h"
#include "stm32mp1xx_exti.h"

typedef enum
{
	FALLING_TRI,  //下降沿触发方式
	RISING_TRI,  //上升沿触发方式
}trigger_t;

//中断RCC章节初始化 PF9 7 8
void hal_interrupt_rcc_init();

//EXTI初始化函数
//EXTI编号 GPIO组号 触发方式
void hal_exti_init(unsigned int extix,unsigned int groupx,trigger_t trix);

//GIC初始化函数
//中断号，中断优先级
void hal_gic_init(unsigned int interruptx,unsigned int priority);

//led初始化函数
void led_init(gpio_t* gpiox,unsigned int pin);


#endif

---key.c函数实现---

#include "key.h"

//中断RCC章节初始化 PF9 7 8
void hal_interrupt_rcc_init()
{
	//RCC章节初始化 PF9 [5]=1
	RCC->MP_AHB4ENSETR |= (0x1 << 5);
	
}

//EXTI初始化函数
//EXTI编号 GPIO组号 触发方式
void hal_exti_init(unsigned int extix,unsigned int groupx,trigger_t trix)
{
	//GPIO章节初始化 设置三个按键为输入模式
	GPIOF->MODER &= (~(0x3 << 2*extix));

	//EXTI章节初始化,引脚信号与EXTI连接
	//1.EXIT_EXTICR组 0x05
	EXTI->EXTICR[extix/4] &= (~(0xff << ((extix%4)*8)));
	EXTI->EXTICR[extix/4] |= (groupx << ((extix%4)*8));

	//2.EXTI_FTSR1 设置下降沿触发方式
	if(trix == FALLING_TRI)
		EXTI->FTSR1 |= (0x1 << extix);
	else
		EXTI->RTSR1 |= (0x1 << extix);
		
	//3.EXTI_IMR1 设置中断不屏蔽 =1
	EXTI->C1IMR1 |= (0x1 << extix);

}

//GIC初始化函数
//中断号，中断优先级
void hal_gic_init(unsigned int interruptx,unsigned int priority)
{
	//GICD初始化
	//1.GICD_CTRL 使能组0 [0]=1
	GICD->CTRL |= (0x1 << 0);

	//2.GICD_ISENABLER组 设置GICD层中断使能
	GICD->ISENABLER[interruptx/32] |= (0x1 << (interruptx % 32));

	//3.GICD_IPRIORITYR组 设置中断优先级  操作高5位
	GICD->IPRIORITYR[interruptx/4] &= (~(0x1f << (interruptx % 4 * 8 + 3)));
	GICD->IPRIORITYR[interruptx/4] |= (priority << (interruptx % 4  * 8 + 3));

	//4.GICD_ITARGETSR组 设置中断目标分配给CPU0
	GICD->ITARGETSR[interruptx/4] &= (~(0x3 << (interruptx % 4 * 8)));
	GICD->ITARGETSR[interruptx/4] |= (0x1 << (interruptx % 4 * 8));

	//GICC初始化
	//1.GICC_CTRL 设置GICC层组0使能 [0]=1
	GICC->CTRL |= (0x1 << 0);

	//2.GICC_PMR 设置GICC层中断优先级 
	GICC->PMR |= ((priority+1) << 3);
}

//led灯初始化
//参数1：GPIO组号
//参数2：引脚编号
void led_init(gpio_t* gpiox,unsigned int pin)
{
	//1输出模式 
	gpiox->MODER &= ~(0x3 << (pin*2));
	gpiox->MODER |= (0x1 << (pin*2));

	//2输出类型
	gpiox->OTYPER &= (~(0x1 << pin));

	//3输出速率
	gpiox->OSPEEDR &= ~(0x3 << (pin*2));
	
	//4拉电阻
	gpiox->PUPDR &= ~(0x3 << (pin*2));
}

---do_irq.c终端处理函数---

#include "key.h"

extern void printf(const char *fmt, ...);

//中断处理函数
void do_irq(void) 
{
	//1获取中断号 IAR[9:0]
	unsigned int num = 0;
	num = GICC->IAR & 0x3ff;
	
	//2判断中断号，并且打印一句话
	switch(num)
	{
	case 99:
		printf("KEY1按键中断,LED3灯取反\n");
		
		//led3灯状态取反
		GPIOE->ODR ^= (0x1 << 8);

		//3清除EXTI层中断挂起标志位 [9]=1
		//EXTI_FDR1 [9]=1
		EXTI->FPR1 |= (0x1 << 9);

		//4清除GICD层中断挂起标志位
		//GICD_ICPENDR3 [3]=1
		GICD->ICPENDR[3] |= (0x1 << 3);

		break;

	case 97:
		printf("KEY2按键中断，LED2灯取反\n");

		//led2灯状态取反
		GPIOF->ODR ^= (0x1 << 10);

		//清除EXTI层中断挂起标志位 [9]=1
		EXTI->FPR1 |= (0x1 << 7);
		GICD->ICPENDR[3] |= (0x1 << 1);
		
		break;

	case 98:
		printf("KEY3按键中断，LED1灯取反\n");	
	
		//led1灯状态取反
		GPIOE->ODR ^= (0x1 << 10);
	
		EXTI->FPR1 |= (0x1 << 8);
		GICD->ICPENDR[3] |= (0x1 << 2);
	
		break;
	}
	
	//5清楚获取到的中断号
	GICC->EOIR = num;

}

---main.c测试文件---

#include "key.h"

extern void printf(const char *fmt, ...);

void delay_ms(int ms)

{
	int i,j;
	for(i = 0; i < ms;i++)
		for (j = 0; j < 1800; j++);
}

#define GPIO_PIN10 10  //引脚编号
#define GPIO_PIN8 8
#define EXTI9 9   //EXTI编号
#define EXTI7 7
#define EXTI8 8
#define GPIOF_GROUP 0x05   //GPIOF组号
#define KEY1_ID 99   //中断号
#define KEY2_ID 97
#define KEY3_ID 98
#define KEY1_PRIORITY 9   //中断优先级
#define KEY2_PRIORITY 7
#define KEY3_PRIORITY 8

int main()
{
	//使能三盏灯PE10 PF10 PE8
	RCC->MP_AHB4ENSETR |= (0x3 << 4);

	//led初始化函数
	led_init(GPIOE,GPIO_PIN10);
	led_init(GPIOF,GPIO_PIN10);
	led_init(GPIOE,GPIO_PIN8);

	//中断RCC章节初始化 PF9 7 8
	hal_interrupt_rcc_init();

	//EXTI初始化函数
	hal_exti_init(EXTI9,GPIOF_GROUP,FALLING_TRI);
	hal_exti_init(EXTI7,GPIOF_GROUP,FALLING_TRI);
	hal_exti_init(EXTI8,GPIOF_GROUP,FALLING_TRI);

	//GIC初始化函数
	hal_gic_init(KEY1_ID,KEY1_PRIORITY);
	hal_gic_init(KEY2_ID,KEY2_PRIORITY);
	hal_gic_init(KEY3_ID,KEY3_PRIORITY);

	while(1)
	{

	}

	return 0;

}