【STM32】EXTI---外部中断/事件控制器

Author：AXYZdong 自动化专业工科男
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文章目录

电赛前夜的一篇文章，明天8点开题，加油！一、EXTI 简介二、EXTI 功能框图三、中断/事件线四、EXTI 初始化结构体4.1. 中断/事件线4.2. EXTI 模式4.3. 触发类型4.4. EXTI 控制五、外部中断控制实验编程要点EXTI.hEXTI.cmain.c实验现象六、总结

开发板：stm32f407VET6开发环境：keil5 MDK

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电赛前夜的一篇文章，明天8点开题，加油！

一、EXTI 简介

外部中断/事件控制器(EXTI)管理了控制器的 23个中断/事件线。每个中断/事件线都对应有一个边沿检测器，可以实现输入信号的上升沿检测和下降沿的检测。EXTI 可以实现对每个中断/事件线进行单独配置，可以单独配置为中断或者事件，以及触发事件的属性。

二、EXTI 功能框图

信号线上斜杠并标注 “23” 字样：表示在控制器内部类似的信号线路有23个。EXTI是挂靠在APB2总线上的。

三、中断/事件线

EXTI0至 EXTI15用于 GPIO，通过编程控制可以实现任意一个 GPIO作为EXTI 的输入源SYSCFG外部中断配置寄存器 1 配置EXTI0▲ EXTI0输入源选择

四、EXTI 初始化结构体

typedef struct{//中断/事件线uint32_t EXTI_Line;/*!< Specifies the EXTI lines to be enabled or disabled.This parameter can be any combination value of @ref EXTI_Lines *///EXTI 模式EXTIMode_TypeDef EXTI_Mode; /*!< Specifies the mode for the EXTI lines.This parameter can be a value of @ref EXTIMode_TypeDef *///触发类型EXTITrigger_TypeDef EXTI_Trigger; /*!< Specifies the trigger signal active edge for the EXTI lines.This parameter can be a value of @ref EXTITrigger_TypeDef *///EXTI 控制FunctionalState EXTI_LineCmd;/*!< Specifies the new state of the selected EXTI lines.This parameter can be set either to ENABLE or DISABLE */ }EXTI_InitTypeDef;

4.1. 中断/事件线

#define EXTI_Line0 ((uint32_t)0x00001)/*!< External interrupt line 0 */#define EXTI_Line1 ((uint32_t)0x00002)/*!< External interrupt line 1 */#define EXTI_Line2 ((uint32_t)0x00004)/*!< External interrupt line 2 */#define EXTI_Line3 ((uint32_t)0x00008)/*!< External interrupt line 3 */#define EXTI_Line4 ((uint32_t)0x00010)/*!< External interrupt line 4 */#define EXTI_Line5 ((uint32_t)0x00020)/*!< External interrupt line 5 */#define EXTI_Line6 ((uint32_t)0x00040)/*!< External interrupt line 6 */#define EXTI_Line7 ((uint32_t)0x00080)/*!< External interrupt line 7 */#define EXTI_Line8 ((uint32_t)0x00100)/*!< External interrupt line 8 */#define EXTI_Line9 ((uint32_t)0x00200)/*!< External interrupt line 9 */#define EXTI_Line10((uint32_t)0x00400)/*!< External interrupt line 10 */#define EXTI_Line11((uint32_t)0x00800)/*!< External interrupt line 11 */#define EXTI_Line12((uint32_t)0x01000)/*!< External interrupt line 12 */#define EXTI_Line13((uint32_t)0x02000)/*!< External interrupt line 13 */#define EXTI_Line14((uint32_t)0x04000)/*!< External interrupt line 14 */#define EXTI_Line15((uint32_t)0x08000)/*!< External interrupt line 15 */#define EXTI_Line16((uint32_t)0x10000)/*!< External interrupt line 16 Connected to the PVD Output */#define EXTI_Line17((uint32_t)0x20000)/*!< External interrupt line 17 Connected to the RTC Alarm event */#define EXTI_Line18((uint32_t)0x40000)/*!< External interrupt line 18 Connected to the USB OTG FS Wakeup from suspend event */#define EXTI_Line19((uint32_t)0x80000)/*!< External interrupt line 19 Connected to the Ethernet Wakeup event */#define EXTI_Line20((uint32_t)0x00100000) /*!< External interrupt line 20 Connected to the USB OTG HS (configured in FS) Wakeup event */#define EXTI_Line21((uint32_t)0x00200000) /*!< External interrupt line 21 Connected to the RTC Tamper and Time Stamp events */ #define EXTI_Line22((uint32_t)0x00400000) /*!< External interrupt line 22 Connected to the RTC Wakeup event */

4.2. EXTI 模式

typedef enum{EXTI_Mode_Interrupt = 0x00, //产生中断EXTI_Mode_Event = 0x04 //产生事件}EXTIMode_TypeDef;

4.3. 触发类型

typedef enum{EXTI_Trigger_Rising = 0x08, //上升沿EXTI_Trigger_Falling = 0x0C, //下降沿EXTI_Trigger_Rising_Falling = 0x10 //上升沿和下降沿都触发}EXTITrigger_TypeDef;

4.4. EXTI 控制

使能 EXTI，一般都是使能，ENABLE

五、外部中断控制实验

按键作为外部输入，按下按键触发外部中断，进入中断服务函数。

编程要点

初始化LED的GPIO开启按键GPIO时钟和SYSCFG时钟配置按键GPIO为输入模式配置NVIC按键GPIO连接到EXTI输入配置EXTI中断/事件线EXTI中断服务函数

EXTI.h

// =============================================# @Time : -10-09# @Author : AXYZdong# @CSDN : /qq_43328313# @FileName: exti.h# @Software: keil5 MDK// =============================================#ifndef _EXTI_H#define _EXTI_H//引脚宏定义 /*******************************************************/ #define KEY1_EXTI_PORTSOURCE EXTI_PortSourceGPIOE#define KEY1_EXTI_PINSOURCE EXTI_PinSource3#define KEY1_EXTI_LINE EXTI_Line3#define KEY1_EXTI_IRQEXTI3_IRQn#define KET1_IRQHandler EXTI3_IRQHandlervoid EXTI_Config(void);#endif

EXTI.c

// =============================================# @Time : -10-09# @Author : AXYZdong# @CSDN : /qq_43328313# @FileName: EXTI.c# @Software: keil5 MDK// =============================================#include "stm32f4xx.h"#include "exti.h"#include "bsp_key.h"#include "delay.h"uint8_t flag = 0x00;void EXTI_Config(void){EXTI_InitTypeDef EXTI_InitStructure;NVIC_InitTypeDef NVIC_InitStructure;/* 使能 SYSCFG 时钟，使用 GPIO 外部中断时必须使能 SYSCFG 时钟*/RCC_APB2PeriphClockCmd(RCC_APB2Periph_SYSCFG, ENABLE);/* 连接 EXTI 中断源到 key1 引脚 */ SYSCFG_EXTILineConfig(KEY1_EXTI_PORTSOURCE, KEY1_EXTI_PINSOURCE);EXTI_InitStructure.EXTI_Line = KEY1_EXTI_LINE;//连接中断源EXTI_InitStructure.EXTI_LineCmd = ENABLE;//使能中断EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;//中断模式EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling; //下降沿触发EXTI_Init(&EXTI_InitStructure);NVIC_PriorityGroupConfig(NVIC_PriorityGroup_1);NVIC_InitStructure.NVIC_IRQChannel = KEY1_EXTI_IRQ;//中断通道NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=1; //抢占优先级1NVIC_InitStructure.NVIC_IRQChannelSubPriority =1; //子优先级1NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //IRQ通道使能NVIC_Init(&NVIC_InitStructure);//根据指定的参数初始化VIC寄存器}void KET1_IRQHandler(void){delay_ms(10);if(KEY1 == RESET){flag++;flag &= 0x01;flag == RESET ? GPIO_SetBits(GPIOA,GPIO_Pin_6) : GPIO_ResetBits(GPIOA,GPIO_Pin_6);}while(!KEY1);EXTI_ClearITPendingBit(KEY1_EXTI_LINE);}

main.c

// =============================================# @Time : -10-09# @Author : AXYZdong# @CSDN : /qq_43328313# @FileName: main.c# @Software: keil5 MDK// =============================================#include "stm32f4xx.h"#include "bsp_led.h"#include "bsp_key.h"#include "sys.h"#include "delay.h"#include "exti.h"int main(){delay_init(168); //初始化延时函数LED_GPIO_Config();//初始化LED端口 KEY_Init(); //初始化与按键连接的硬件接口EXTI_Config();//初始化外部中断while(1){}}