STM32F103學(xué)習(xí)筆記五外部中斷

1、STM32F103學(xué)習(xí)筆記（五）外部中斷首先是外部中斷基本的概念：STM32的每個(gè)IO都可以作為外部中斷的中斷輸入口，這點(diǎn)也是STM32的強(qiáng)大之處。STM32F103的中斷控制器支持19個(gè)外部中斷/事件請(qǐng)求。每個(gè)中斷設(shè)有狀態(tài)位，每個(gè)中斷/事件都有獨(dú)立的觸發(fā)和屏蔽設(shè)置。STM32F103的19個(gè)外部中斷為：線015:對(duì)應(yīng)外部IO口的輸入中斷。線16:連接到PVD輸由。線17:連接到RTC鬧鐘事件。線18:連接到USB喚醒事件。線1618還沒(méi)有學(xué)到只看了線015每個(gè)中斷線對(duì)應(yīng)著7個(gè)GPIO口，形成映射關(guān)系，以線0為例：它對(duì)應(yīng)了GPIOA.0、GPIOB.0、GPIOC.0、GPIOD.0、GPIO

2、E.0、GPIOF.0、GPIOG.0。而中斷線每次只能連接到1個(gè)IO口上，這樣就需要通過(guò)配置來(lái)決定對(duì)應(yīng)的中斷線配置到哪個(gè)GPIO上了。下面我們看看GPIO跟中斷線的映射關(guān)系圖：根據(jù)映射關(guān)系，就開(kāi)始配置按鍵對(duì)應(yīng)GPIO口和中斷的映射了：csharpviewplaincopy<prename=codeclass=csharp><prename=codeclass=html>voidEXTIX_Init(void)EXTI_InitTypeDefEXTI_InitStructure;NVIC_InitTypeDefNVIC_InitStructure;KEY_Init();

3、/按鍵端口初始化RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO,ENABLE);/使能復(fù)用功能時(shí)鐘/GPIOE.2中斷線以及中斷初始化配置下降沿觸發(fā)GPIO_EXTILineConfig(GPIO_PortSourceGPIOE,GPIO_PinSource2);EXTI_InitStructure.EXTI_Line=EXTI_Line2;/KEY2EXTI_InitStructure.EXTI_Mode=EXTI_Mode_Interrupt;EXTI_InitStructure.EXTI_Trigger=EXTI_Trigger_Falling;EX

4、TI_InitStructure.EXTI_LineCmd=ENABLE;EXTI_Init(&EXTI_InitStructure);根據(jù)EXTI_InitStruct中指定的參數(shù)初始化外設(shè)EXTI寄存器/GPIOE.3中斷線以及中斷初始化配置下降沿觸發(fā)KEY1GPIO_EXTILineConfig(GPIO_PortSourceGPIOE,GPIO_PinSource3);EXTI_InitStructure.EXTI_Line=EXTI_Line3;EXTI_Init(&EXTI_InitStructure);根據(jù)EXTI_InitStruct中指定的參數(shù)初始化外設(shè)EXT

5、I寄存器/GPIOE.4中斷線以及中斷初始化配置下降沿觸發(fā)/KEY0GPIO_EXTILineConfig(GPIO_PortSourceGPIOE,GPIO_PinSource4);EXTI_InitStructure.EXTI_Line=EXTI_Line4;EXTI_Init(&EXTI_InitStructure);根據(jù)EXTI_InitStruct中指定的參數(shù)初始化外設(shè)EXTI寄存器/GPIOA,0中斷線以及中斷初始化配置上升沿觸發(fā)PA0WK_UPGPIO_EXTILineConfig(GPIO_PortSourceGPIOA,GPIO_PinSource0);EXTI_In

6、itStructure.EXTI_Line=EXTI_Line0;EXTI_InitStructure.EXTI_Trigger=EXTI_Trigger_Rising;EXTI_Init(&EXTI_InitStructure);根據(jù)EXTI_InitStruct中指定的參數(shù)初始化外設(shè)EXTI寄存器NVIC_InitStructure.NVIC_IRQChannel=EXTI0_IRQn;使能按鍵WK_UP所在的外部中斷通道NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=0x02;搶占優(yōu)先級(jí)2,NVIC_InitStructu

7、re.NVIC_IRQChannelSubPriority=0x03;子優(yōu)先級(jí)3NVIC_InitStructure.NVIC_IRQChannelCmd=ENABLE;使能外部中斷通道NVIC_Init(&NVIC_InitStructure);NVIC_InitStructure.NVIC_IRQChannel=EXTI2_IRQn;使能按鍵KEY2所在的外部中斷通道NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=0x02;搶占優(yōu)先級(jí)2,NVIC_InitStructure.NVIC_IRQChannelSubPriorit

8、y=0x02;子優(yōu)先級(jí)2NVIC_InitStructure.NVIC_IRQChannelCmd=ENABLE;使能外部中斷通道NVIC_Init(&NVIC_InitStructure);NVIC_InitStructure.NVIC_IRQChannel=EXTI3_IRQn;使能按鍵KEY1所在的外部中斷通道NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=0x02;搶占優(yōu)先級(jí)2NVIC_InitStructure.NVIC_IRQChannelSubPriority=0x01;子優(yōu)先級(jí)1NVIC_InitStructur

9、e.NVIC_IRQChannelCmd=ENABLE;使能外部中斷通道NVIC_Init(&NVIC_InitStructure);根據(jù)NVIC_InitStruct中指定的參數(shù)初始化外設(shè)NVIC寄存器NVIC_InitStructure.NVIC_IRQChannel=EXTI4_IRQn;使能按鍵KEY0所在的外部中斷通道NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=0x02;搶占優(yōu)先級(jí)2NVIC_InitStructure.NVIC_IRQChannelSubPriority=0x00;子優(yōu)先級(jí)0NVIC_InitSt

10、ructure.NVIC_IRQChannelCmd=ENABLE;使能外部中斷通道NVIC_Init(&NVIC_InitStructure);根據(jù)NVIC_InitStruct中指定的參數(shù)初始化外設(shè)NVIC寄存器外部中斷0服務(wù)程序voidEXTI0_IRQHandler(void)delay_ms(10);/消抖if(KEY3=1)/WK_UP按鍵BEEP=!BEEP;EXTI_ClearITPendingBit(EXTI_Line0);/清除LINE0上的中斷標(biāo)志位外部中斷2服務(wù)程序voidEXTI2_IRQHandler(void)delay_ms(10);消抖if(KEY2=0)按鍵KEY2LED0=!LED0;EXTI_ClearITPendingBit(EXTI_Line2);清除LINE2上的中斷標(biāo)志位外部中斷3服務(wù)程序voidEXTI3_IRQHandler(void)delay_ms(10);/消抖if(KEY1=0)按鍵KEY1LED1=!LED1;EXTI_ClearITPendingBit(EXTI_