思路:按键->EXTI->GIC->CPU->异常向量表
//使能GPIOF时钟
//设置PF9管脚为输入(KEY1)
//设置PF9作为EXTI9事件的输入(事件编号对应管脚号)
//设置下降沿使能检测EXTI9事件 (也可设置上升沿没有下降沿严谨方便,不同场景不同选择)
//设置EXTI9事件不屏蔽? ?(只有不屏蔽中断事件才能继续执行)
//GICD使能EXTI9(99号)中断? (给中断信号使能)
//GICD 设置99号中断的优先级? ?(中断信号的优先级要设置的高)
//选择CPU0处理当前中断
//全局使能组0中断被转发到GICC? (在组0? 组1 选择 组0)
//设置中断的优先级掩码? (让掩码的优先级降到最低,使自己的中断优先级高于他)
//允许组0中断被CPU处理
irq就是IRQ中断
key_it.h
#ifndef __KEY_IT_H__
#define __KEY_IT_H__
#include"stm32mp1xx_gpio.h"
#include"stm32mp1xx_gic.h"
#include"stm32mp1xx_exti.h"
#include"stm32mp1xx_rcc.h"
#include "led.h"
void key1_it_config();
void key2_it_config();
void key3_it_config();
void delay(int ms);
#endif
key_it.c
#include"key_it.h"
void key1_it_config()
{
//使能GPIOF时钟
RCC->MP_AHB4ENSETR |= (0x1<<5);
//设置PF9管脚为输入
GPIOF->MODER &= (~(0x3<<18));
//设置PF9作为EXTI9事件的输入
EXTI->EXTICR3 &= (~(0x1f<<8));
EXTI->EXTICR3 |= (0x05<<8);
//设置下降沿使能检测EXTI9事件
EXTI->FTSR1 |= (0x1<<9);
//设置EXTI9事件不屏蔽
EXTI->C1IMR1 |= (0x1<<9);
//GICD使能EXTI9(99号)中断
GICD->ISENABLER[3] |= (0x1<<3);
//GICD 设置99号中断的优先级
GICD->IPRIORITYR[24] &= (~(0x1f<<27));
//选择CPU0处理当前中断
GICD->ITARGETSR[24] |= (0x1<<24);
//全局使能组0中断被转发到GICC
GICD->CTRL |= (0X1);
//设置中断的优先级掩码
GICC->PMR |= (0x1f<<3);
//允许组0中断被CPU处理
GICC->CTRL |= (0x1);
}
void key2_it_config()
{
//使能GPIOF时钟
RCC->MP_AHB4ENSETR |= (0x1<<5);
//设置PF7管脚为输入
GPIOF->MODER &= (~(0x3<<14));
//设置PF7作为EXTI7事件的输入
EXTI->EXTICR2 &= (~(0x1f<<24));
EXTI->EXTICR2 |= (0x05<<24);
//设置下降沿使能检测EXTI7事件
EXTI->FTSR1 |= (0x1<<7);
//设置EXTI7事件不屏蔽
EXTI->C1IMR1 |= (0x1<<7);
//GICD使能EXTI7(97号)中断
GICD->ISENABLER[3] |= (0x1<<1);
//GICD 设置97号中断的优先级
GICD->IPRIORITYR[24] &= (~(0x1f<<11));
//选择CPU0处理当前中断
GICD->ITARGETSR[24] |= (0x1<<8);
//全局使能组0中断被转发到GICC
GICD->CTRL |= (0X1);
//设置中断的优先级掩码
GICC->PMR |= (0x1f<<3);
//允许组0中断被CPU处理
GICC->CTRL |= (0x1);
}
void key3_it_config()
{
//使能GPIOF时钟
RCC->MP_AHB4ENSETR |= (0x1<<5);
//设置PF8管脚为输入
GPIOF->MODER &= (~(0x3<<16));
//设置PF8作为EXTI8事件的输入
EXTI->EXTICR3 &= (~(0x1f));
EXTI->EXTICR3 |= (0x05);
//设置下降沿使能检测EXTI8事件
EXTI->FTSR1 |= (0x1<<8);
//设置EXTI8事件不屏蔽
EXTI->C1IMR1 |= (0x1<<8);
//GICD使能EXTI8(98号)中断
GICD->ISENABLER[3] |= (0x1<<2);
//GICD 设置98号中断的优先级
GICD->IPRIORITYR[24] &= (~(0x1f<<19));
//选择CPU0处理当前中断
GICD->ITARGETSR[24] |= (0x1<<16);
//全局使能组0中断被转发到GICC
GICD->CTRL |= (0X1);
//设置中断的优先级掩码
GICC->PMR |= (0x1f<<3);
//允许组0中断被CPU处理
GICC->CTRL |= (0x1);
}
do_irq.c
#include "key_it.h"
extern void printf(const char *fmt, ...);
unsigned int i = 0;
//延时函数
void delay(int ms)
{
int i,j;
for(i=0;i<ms;i++)
{
for(j=0;j<2000;j++);
}
}
void do_irq(void)
{
//LED灯初始化
all_led_init();
int irqno = (GICC->IAR & 0x3ff);
switch (irqno)
{
case 99: // key1
printf("KEY1_INT\n");
//点亮两个灯
led1_on();
led3_on();
delay(1000);
//熄灭两个灯
led1_off();
led3_off();
delay(1000);
// 清除GICD的中断排队标志
GICD->ICPENDR[3] |= (0x1<<3);
// 清除exti的事件触发标志
EXTI->FPR1 |= (0x1<<9);
break;
case 97: // KEY2
printf("KEY2_INT\n");
//点亮一个灯
led1_on();
delay(1000);
//熄灭三个灯
led1_off();
led2_off();
led3_off();
delay(1000);
// 清除GICD的中断排队标志
GICD->ICPENDR[3] |= (0x1<<1);
// 清除exti的事件触发标志
EXTI->FPR1 |= (0x1<<7);
break;
case 98: // key3
printf("KEY3_INT\n");
//延时点亮三个灯,一个灯亮的同时下个灯灭
led1_on();
delay(1000);
led1_off();
led2_on();
delay(1000);
led2_off();
led3_on();
delay(1000);
led3_off();
// 清除GICD的中断排队标志
GICD->ICPENDR[3] |= (0x1<<2);
// 清除exti的事件触发标志
EXTI->FPR1 |= (0x1<<8);
break;
}
// 清除中断号
GICC->EOIR = irqno;
}
main.c
#include "key_it.h"
void delay(int ms)
{
int i,j;
for(i=0;i<ms;i++)
{
for(j=0;j<2000;j++);
}
}
int main()
{
key1_it_config();
key2_it_config();
key3_it_config();
while (1)
{
printf("do main...\n");
delay(1000);
}
}