GPIO_InitTypeDef GPIO_InitStructure; EXTI_InitTypeDef EXTI_InitStructure; NVIC_InitTypeDef NVIC_InitStructure; RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB|RCC_APB2Periph_AFIO,ENABLE); GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9; GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU; GPIO_Init(GPIOB,&GPIO_InitStructure); GPIO_EXTILineConfig(GPIO_PortSourceGPIOB,GPIO_PinSource9); EXTI_ClearITPendingBit(EXTI_Line9); EXTI_InitStructure.EXTI_Line = EXTI_Line9; EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt; EXTI_InitStructure.EXTI_LineCmd = ENABLE; EXTI_Init(&EXTI_InitStructure); NVIC_InitStructure.NVIC_IRQChannel = EXTI9_5_IRQn; NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0; NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1; NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; NVIC_Init(&NVIC_InitStructure);

这段代码是在STM32中初始化外部中断EXTI9，其中GPIOB的Pin9被配置为输入模式，并使用上拉电阻，同时将其与外部中断线EXTI_Line9连接。然后，设置外部中断的触发模式为中断模式，并使能中断线，最后配置中断优先级和使能中断。这段代码的作用是使得当GPIOB的Pin9引脚发生状态变化时，即可触发相应的中断服务程序。

相关问题

在保持原来的代码逻辑的条件下，根据STM32F407的特性，把下面STM32F1的代码移植到STM32F407。void ExtiGpioInit(void) { GPIO_InitTypeDef GPIO_InitStruct; RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOC|RCC_APB2Periph_AFIO, ENABLE); GPIO_InitStruct.GPIO_Mode = GPIO_Mode_IN_FLOATING; GPIO_InitStruct.GPIO_Pin = GPIO_Pin_4|GPIO_Pin_5 ; GPIO_InitStruct.GPIO_Speed = GPIO_Speed_50MHz; GPIO_Init(GPIOC, &GPIO_InitStruct); } void ExtiNvicInit(void) { NVIC_InitTypeDef NVIC_InitStructure; NVIC_InitStructure.NVIC_IRQChannel = EXTI4_IRQn; NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0; NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1; NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; NVIC_Init(&NVIC_InitStructure); NVIC_InitStructure.NVIC_IRQChannel = EXTI9_5_IRQn ; NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0; NVIC_InitStructure.NVIC_IRQChannelSubPriority = 2; NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; NVIC_Init(&NVIC_InitStructure); } void ExtiModeInit(void) { EXTI_InitTypeDef EXTI_InitStructure; GPIO_EXTILineConfig(GPIO_PortSourceGPIOC, GPIO_PinSource4); EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt; EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling; EXTI_InitStructure.EXTI_Line = EXTI_Line4; EXTI_InitStructure.EXTI_LineCmd = ENABLE; EXTI_Init(&EXTI_InitStructure); GPIO_EXTILineConfig(GPIO_PortSourceGPIOC, GPIO_PinSource5); EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt; EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling; EXTI_InitStructure.EXTI_Line = EXTI_Line5; EXTI_InitStructure.EXTI_LineCmd = ENABLE; EXTI_Init(&EXTI_InitStructure); }

void ExtiGpioInit(void)
{
GPIO_InitTypeDef GPIO_InitStruct;

RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOC, ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_SYSCFG, ENABLE);

GPIO_InitStruct.GPIO_Mode = GPIO_Mode_IN;
GPIO_InitStruct.GPIO_Pin = GPIO_Pin_4|GPIO_Pin_5 ;
GPIO_InitStruct.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_Init(GPIOC, &GPIO_InitStruct);

}

void ExtiNvicInit(void)
{
NVIC_InitTypeDef NVIC_InitStructure;

NVIC_InitStructure.NVIC_IRQChannel = EXTI4_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);

NVIC_InitStructure.NVIC_IRQChannel = EXTI9_5_IRQn ;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 2;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
}

void ExtiModeInit(void)
{
EXTI_InitTypeDef EXTI_InitStructure;

SYSCFG_EXTILineConfig(EXTI_PortSourceGPIOC, EXTI_PinSource4);
EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling;
EXTI_InitStructure.EXTI_Line = EXTI_Line4;
EXTI_InitStructure.EXTI_LineCmd = ENABLE;
EXTI_Init(&EXTI_InitStructure);

SYSCFG_EXTILineConfig(EXTI_PortSourceGPIOC, EXTI_PinSource5);
EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling;
EXTI_InitStructure.EXTI_Line = EXTI_Line5;
EXTI_InitStructure.EXTI_LineCmd = ENABLE;
EXTI_Init(&EXTI_InitStructure);
}

EXTI_InitTypeDef EXTI_InitStructure; NVIC_InitTypeDef NVIC_InitStructure; KEY_Init(); RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO,ENABLE); GPIO_EXTILineConfig(GPIO_PortSourceGPIOE,GPIO_PinSource2); EXTI_InitStructure.EXTI_Line=EXTI_Line2; EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt; EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling; EXTI_InitStructure.EXTI_LineCmd = ENABLE; EXTI_Init(&EXTI_InitStructure); NVIC_InitStructure.NVIC_IRQChannel = EXTI0_IRQn; NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x02; NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x03; NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; NVIC_Init(&NVIC_InitStructure); 解释每一句代码

这段代码是针对单片机开发的，主要是为了实现对外部中断的响应。下面是每一句代码的解释：

1. EXTI_InitTypeDef EXTI_InitStructure;：定义一个EXTI_InitTypeDef类型的结构体变量EXTI_InitStructure，用于配置外部中断线的触发模式、中断线号等参数。

2. NVIC_InitTypeDef NVIC_InitStructure;：定义一个NVIC_InitTypeDef类型的结构体变量NVIC_InitStructure，用于配置中断优先级等参数。

3. KEY_Init();：初始化按键，具体内容未知。

4. RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO,ENABLE);：开启AFIO时钟，该时钟控制着GPIO的复用功能。

5. GPIO_EXTILineConfig(GPIO_PortSourceGPIOE,GPIO_PinSource2);：配置GPIOE的Pin2引脚为外部中断线2。

6. EXTI_InitStructure.EXTI_Line=EXTI_Line2;：设置外部中断线号为2。

7. EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;：设置外部中断模式为中断模式。

8. EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling;：设置触发模式为下降沿触发。

9. EXTI_InitStructure.EXTI_LineCmd = ENABLE;：使能外部中断线。

10. EXTI_Init(&EXTI_InitStructure);：将以上配置应用到外部中断线2上。

11. NVIC_InitStructure.NVIC_IRQChannel = EXTI0_IRQn;：设置中断通道为外部中断线0，实际上应该是写成EXTI2_IRQn。

12. NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x02;：设置中断优先级为2。

13. NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x03;：设置中断响应优先级为3。

14. NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;：使能中断通道。

15. NVIC_Init(&NVIC_InitStructure);：将以上配置应用到中断控制器上。