STM32F4外部GPIO中断源使用笔记

STM32F4有7个外部GPIO中断源，它们负责分配给每个组的GPIO[15..0]；

对应关系为

外部中断初始化顺序为：

GPIO_InitTypeDef GPIO_InitStructure;

NVIC_InitTypeDef NVIC_InitStructure;

EXTI_InitTypeDef EXTI_InitStructure;

(RCC->AHB1ENR) |= RCC_AHB1ENR_GPIOEEN;//GPIO CLK ENABLE

RCC_APB2PeriphClockCmd(RCC_APB2Periph_SYSCFG, ENABLE);//使能SYSCFG时钟

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_4 | GPIO_Pin_5;

  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN;

  GPIO_InitStructure.GPIO_Speed = GPIO_Fast_Speed;

  GPIO_InitStructure.GPIO_PuPd  = GPIO_PuPd_NOPULL;

  GPIO_Init(GPIOE, &GPIO_InitStructure);

SYSCFG_EXTILineConfig(EXTI_PortSourceGPIOE,EXTI_PinSource4);

SYSCFG_EXTILineConfig(EXTI_PortSourceGPIOE,EXTI_PinSource5);

EXTI_InitStructure.EXTI_Line = EXTI_Line4 | EXTI_Line5;

EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;

EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Rising;

EXTI_InitStructure.EXTI_LineCmd = ENABLE;

EXTI_Init(&EXTI_InitStructure);

NVIC_InitStructure.NVIC_IRQChannel = EXTI4_IRQn;

NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority= 0x01;

NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x02;

NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;

NVIC_Init(&NVIC_InitStructure);

NVIC_InitStructure.NVIC_IRQChannel = EXTI9_5_IRQn;

NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority= 0x00;

NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x02;

NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;

NVIC_Init(&NVIC_InitStructure);

使能SYSCFG时钟及IO口时钟

初始化IO口为输入

设置IO口与中断线的映射关系

初始化线上中断，设置触发条件

配置中断分组（NVIC）并使能中断

编写中断服务函数（清除中断标志位）

运行结果：