NVIC_PriorityGroupConfig(NVIC_PriorityGroup_0); NVIC_InitStructure.NVIC_IRQChannel = EXTI0_IRQn; NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x00; NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x02; NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; NVIC_Init(&NVIC_InitStructure);
时间: 2023-12-06 19:43:44 浏览: 43
这段代码是关于中断优先级的配置,具体来说:
NVIC_PriorityGroupConfig(NVIC_PriorityGroup_0);
这句代码是设置NVIC的优先级分组,一共有4个分组,这里设置为分组0。
NVIC_InitStructure.NVIC_IRQChannel = EXTI0_IRQn;
这句代码是设置触发中断的外部中断线,这里设置为EXTI0。
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x00;
这句代码是设置中断抢占优先级,这里设置为0。
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x02;
这句代码是设置中断响应优先级,这里设置为2。
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
这句代码是使能中断通道。
NVIC_Init(&NVIC_InitStructure);
这句代码是将上述配置应用到NVIC中,使其生效。
相关问题
解释下这串代码NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2); NVIC_InitTypeDef NVIC_InitStructure; NVIC_InitStructure.NVIC_IRQChannel = EXTI15_10_IRQn; NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1; NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1; NVIC_Init(&NVIC_InitStructure);
这段代码是用于配置中断优先级的设置。让我逐行解释:
1. `NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);` - 这个函数用于配置中断优先级分组。`NVIC_PriorityGroup_2` 表示将中断优先级分为两组,其中一组用于抢占优先级,另一组用于子优先级。
2. `NVIC_InitTypeDef NVIC_InitStructure;` - 定义了一个名为 `NVIC_InitStructure` 的类型为 `NVIC_InitTypeDef` 的变量。
3. `NVIC_InitStructure.NVIC_IRQChannel = EXTI15_10_IRQn;` - 设置中断通道为 `EXTI15_10_IRQn`,表示要配置的是外部中断线15到10的中断通道。
4. `NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;` - 设置中断通道的使能状态为启用。这意味着中断通道将会被使能,可以触发中断。
5. `NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;` - 设置抢占优先级为1。抢占优先级用于确定在多个中断同时发生时,哪个中断具有更高的优先级。
6. `NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;` - 设置子优先级为1。子优先级用于确定在同一抢占优先级内,不同中断之间的优先级关系。
7. `NVIC_Init(&NVIC_InitStructure);` - 通过调用 `NVIC_Init()` 函数,将以上配置应用到指定的中断通道上。
这段代码的目的是配置外部中断线15到10的中断通道的优先级,使其能够按照指定的抢占优先级和子优先级进行中断处理。
exti.c 文件代码如下: void EXTIX_Init(void) { NVIC_InitTypeDef NVIC_InitStructure; EXTI_InitTypeDef EXTI_InitStructure; RCC_APB2PeriphClockCmd(RCC_APB2Periph_SYSCFG, ENABLE); SYSCFG_EXTILineConfig(EXTI_PortSourceGPIOE, EXTI_PinSource0); EXTI_InitStructure.EXTI_Line = EXTI_Line0; EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt; EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Rising; //上升沿触发 EXTI_InitStructure.EXTI_LineCmd = ENABLE; EXTI_Init( &EXTI_InitStructure ); //中断 NVIC 配置 NVIC_InitStructure.NVIC_IRQChannel=EXTI0_IRQn; NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x00; NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x02; NVIC_InitStructure.NVIC_IRQChannelCmd=ENABLE; NVIC_Init(&NVIC_InitStructure); } (3)编写 LED 与 KEY 相关代码。 (4)编写中断服务函数。 主函数代码如下: //包含相关头文件 int main(void) { NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2); delay_init(168); LED_Init(); KEY_Init(); EXTIX_Init(); LED0=0; while(1) { } } 4.4 实验练习 在实验 4.3 的框架中补齐代码,以 SW0(E0)做为外部中断输入引脚控制 LED 的亮灭。
LED 与 KEY 相关代码如下:
```
void LED_Init(void) {
GPIO_InitTypeDef GPIO_InitStructure;
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOF, ENABLE);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9 | GPIO_Pin_10;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
GPIO_Init(GPIOF, &GPIO_InitStructure);
}
void KEY_Init(void) {
GPIO_InitTypeDef GPIO_InitStructure;
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOE, ENABLE);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
GPIO_Init(GPIOE, &GPIO_InitStructure);
}
```
中断服务函数如下:
```
void EXTI0_IRQHandler(void) {
if (EXTI_GetITStatus(EXTI_Line0) != RESET) {
LED0 = !LED0;
EXTI_ClearITPendingBit(EXTI_Line0);
}
}
```
完整代码如下:
```
#include "stm32f4xx.h"
#include "delay.h"
#define LED0 PFout(9)
#define LED1 PFout(10)
#define KEY PEin(0)
void LED_Init(void) {
GPIO_InitTypeDef GPIO_InitStructure;
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOF, ENABLE);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9 | GPIO_Pin_10;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
GPIO_Init(GPIOF, &GPIO_InitStructure);
}
void KEY_Init(void) {
GPIO_InitTypeDef GPIO_InitStructure;
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOE, ENABLE);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
GPIO_Init(GPIOE, &GPIO_InitStructure);
}
void EXTIX_Init(void) {
NVIC_InitTypeDef NVIC_InitStructure;
EXTI_InitTypeDef EXTI_InitStructure;
RCC_APB2PeriphClockCmd(RCC_APB2Periph_SYSCFG, ENABLE);
SYSCFG_EXTILineConfig(EXTI_PortSourceGPIOE, EXTI_PinSource0);
EXTI_InitStructure.EXTI_Line = EXTI_Line0;
EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Rising; //上升沿触发
EXTI_InitStructure.EXTI_LineCmd = ENABLE;
EXTI_Init( &EXTI_InitStructure ); //中断 EXTI 配置
NVIC_InitStructure.NVIC_IRQChannel = EXTI0_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x00;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x02;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure); //中断 NVIC 配置
}
int main(void) {
NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);
delay_init(168);
LED_Init();
KEY_Init();
EXTIX_Init();
LED0 = 0;
while(1) {
}
}
void EXTI0_IRQHandler(void) {
if (EXTI_GetITStatus(EXTI_Line0) != RESET) {
LED0 = !LED0;
EXTI_ClearITPendingBit(EXTI_Line0);
}
}
```