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
{
	DISTRIGGER,
	ENTRIGGER  //下降沿触发方式
}trigger_t;

//KEY1->PF9
//RCC,GPIO,EXTI章节初始化
void hal_exti_pf9_init();

//GIC章节初始化
void hal_gic_pf9_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);

//led灯开关函数
void led_on_off(gpio_t* gpiox,unsigned int pin,unsigned int status);


#endif

---key.c函数实现---

#include "key.h"

//RCC,GPIO,EXTI章节初始化
void hal_exti_pf9_init()
{
	//RCC章节初始化 PF9 [5]=1
	RCC->MP_AHB4ENSETR |= (0x1 << 5);
	
	//GPIO章节初始化 [19:18]=00 输入模式
	GPIOF->MODER &= (~(0x3 << 18));
	
	//EXTI章节初始化,引脚信号与EXTI连接
	//1.EXIT_EXTICR3 EXTI9[15:8]=0x05 0101
	EXTI->EXTICR[2] &= (~(0xff << 8));
	EXTI->EXTICR[2] |= (0x05 << 8);
	
	//2.EXTI_FTSR1 设置下降沿触发方式 [9]=1 
	EXTI->FTSR1 |= (0x1 << 9);
	
	//3.EXTI_IMR1 设置中断不屏蔽 [9]=1
	EXTI->C1IMR1 |= (0x1 << 9);	
}


//GIC章节初始化
void hal_gic_pf9_init()
{
	//GICD初始化
	//1.GICD_CTRL 使能组0 [0]=1
	GICD->CTRL |= (0x1 << 0);

	//2.GICD_ISENABLER3 设置GICD层中断使能 3[3]=1
	GICD->ISENABLER[3] |= (0x1 << 3);
	
	//3.GICD_IPRIORITYR24 设置中断优先级 
	//[31:27] = 0b00000
	GICD->IPRIORITYR[24] &= (~(0x1f << 27));

	//4.GICD_ITARGETSR24 设置中断目标分配给CPU0
	//[25:24] = 0b01
	GICD->ITARGETSR[24] &= (~(0x3 << 24));
	GICD->ITARGETSR[24] |= (0x1 << 24);
	
	//GICD_ICPENDRx 清除GICD层中断挂起标志位
	
	//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 [7:3]=0b11111
	GICC->PMR |= (0x1f << 3);
	
}

//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 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_EXTICRn EXTI9[]=0x05 0101
	EXTI->EXTICR[extix/4] &= (~(0xff << ((extix%4)*8)));
	EXTI->EXTICR[extix/4] |= (0x05 << ((extix%4)*8));

	//2.EXTI_FTSR1 设置下降沿触发方式
	EXTI->FTSR1 |= (trix << extix);

	//3.EXTI_IMR1 设置中断不屏蔽 [9]=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_ISENABLER3 设置GICD层中断使能
	GICD->ISENABLER[interruptx/32] |= (0x1 << (interruptx%32));

	//3.GICD_IPRIORITYR24 设置中断优先级 
	GICD->IPRIORITYR[interruptx/4] &= (~(priority << ((interruptx%4)*8+3)));

	//4.GICD_ITARGETSR24 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 [7:3]=0b11111
	GICC->PMR |= ((priority+1) << 3);
}

//函数功能：GPIO引脚初始化
//参数1：GPIO组号
//参数2：引脚编号
void led_init(gpio_t* gpiox,unsigned int pin)
{
	//使能PE10 PF10 PE8
	RCC->MP_AHB4ENSETR |= (0x3 << 4);

	//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));
}

//函数功能：GPIO引脚操作 1 点亮，0 熄灭
//参数1：GPIO组号
//参数2：引脚编号
//参数3：写内容
void led_on_off(gpio_t* gpiox,unsigned int pin,unsigned int status)
{
	if(status == 0)  //熄灭
	{
		gpiox->ODR &= ~(0x1 << pin);	
	}else
	{
		gpiox->ODR |= (0x1 << pin);	
	}
}

---do_irq.c终端处理函数---

#include "key.h"

extern void printf(const char *fmt, ...);
int flag1=0;
int flag2=0;
int flag3=0;
//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\n");
		
		//led3灯状态取反
		if(flag1%2 == 0)
			led_on_off(GPIOE,8,1);
		else
			led_on_off(GPIOE,8,0);

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

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

		flag1++;
		break;

	case 97:
		printf("KEY2按键中断\n");

		//led2灯状态取反
		if(flag2%2 == 0)
			led_on_off(GPIOF,10,1);
		else
			led_on_off(GPIOF,10,0);

		EXTI->FPR1 |= (0x1 << 7);
		GICD->ICPENDR[3] |= (0x1 << 1);
		
		flag2++;
		break;

	case 98:
		printf("KEY3按键中断\n");	
	
		//led1灯状态取反
		if(flag3%2 == 0)
			led_on_off(GPIOE,10,1);
		else
			led_on_off(GPIOE,10,0);
	
		EXTI->FPR1 |= (0x1 << 8);
		GICD->ICPENDR[3] |= (0x1 << 2);
	
		flag3++;
		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++);

}

int main()

{
	//pf9初始化
	hal_exti_pf9_init();
	hal_gic_pf9_init();

	//EXTI初始化函数
    hal_exti_init(7,0x05,ENTRIGGER);
	hal_exti_init(8,0x05,ENTRIGGER);

	//GIC初始化函数
	hal_gic_init(97,1);
	hal_gic_init(98,1);

	//led初始化函数
	led_init(GPIOE,10);
	led_init(GPIOF,10);
	led_init(GPIOE,8);

	while(1)

	{

	}
	return 0;

}

4.实验现象：