void EXTI_Config(void) { EXTI_InitTypeDef EXTI_InitStructure; EXTI_DeInit(); //EXTI初始化 NVIC_DeInit(); //中断优先级初始化 NVIC_SetVectorTable(NVIC_VectTab_FLASH, 0x0); NVIC_PriorityGroupConfig(NVIC_PriorityGroup_1); //抢占优先级:0/1 从优先级0-7 /* Enable the USART3 Interrupt */ NVIC_InitStructure.NVIC_IRQChannel = USART3_IRQChannel; NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1; NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0; NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; NVIC_Init(&NVIC_InitStructure); NVIC_InitStructure.NVIC_IRQChannel = EXTI15_10_IRQChannel; //中断通道 NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0; //强占优先级 NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0; //次优先级 NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //通道中断使能 NVIC_Init(&NVIC_InitStructure); //初始化中断 GPIO_EXTILineConfig(GPIO_PortSourceGPIOC,GPIO_PinSource12); //PC12设置到EXTI12上 EXTI_DeInit(); EXTI_InitStructure.EXTI_Line = EXTI_Line12; EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt; EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling; //EXTI_Trigger_Falling; EXTI_InitStructure.EXTI_LineCmd = ENABLE; EXTI_Init(&EXTI_InitStructure); 解释一下这段代码
时间: 2024-04-17 16:02:06 浏览: 15
这段代码主要是用来配置单片机的外部中断(EXTI)和中断向量表(NVIC)。
首先,通过调用`EXTI_DeInit()`和`NVIC_DeInit()`函数进行外部中断和中断向量表的初始化。
然后,使用`NVIC_SetVectorTable()`函数设置中断向量表的位置为Flash,并设置偏移地址为0x0。
接下来,通过调用`NVIC_PriorityGroupConfig()`函数设置中断优先级分组,这里设置为分组1,抢占优先级为0/1,从优先级0-7。
然后,使用`NVIC_Init()`函数初始化USART3的中断,设置中断通道为USART3,并设置抢占优先级为1,次优先级为0,并使能该中断通道。
接着,使用`GPIO_EXTILineConfig()`函数将PC12引脚配置到EXTI12上,表示PC12引脚触发的中断将会与EXTI_Line12关联。
再次调用`EXTI_DeInit()`函数进行外部中断的初始化。
最后,使用`EXTI_Init()`函数初始化EXTI_InitStructure结构体,并设置外部中断线为EXTI_Line12,模式为中断模式,触发方式为下降沿触发,使能该外部中断线。
这段代码的作用是配置USART3和PC12引脚的外部中断,并设置相应的中断优先级和触发方式。具体的外部中断处理和中断服务程序需要根据实际需求进行编写。
相关问题
单片机通过外部中断测量上升沿数量测量方波频率
好的,下面是一份基于STM32单片机的代码,可以通过外部中断测量上升沿数量来计算方波信号的频率:
```c
#include "stm32f10x.h"
#define TIMx TIM2
#define TIMx_IRQn TIM2_IRQn
volatile uint32_t g_count = 0;
volatile uint32_t g_frequency = 0;
void TIMx_IRQHandler(void)
{
if (TIM_GetITStatus(TIMx, TIM_IT_Update) != RESET)
{
g_count = 0;
TIM_ClearITPendingBit(TIMx, TIM_IT_Update);
}
}
void EXTI9_5_IRQHandler(void)
{
if (EXTI_GetITStatus(EXTI_Line5) != RESET)
{
g_count++;
EXTI_ClearITPendingBit(EXTI_Line5);
}
}
void TIMx_Configuration(void)
{
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
TIM_DeInit(TIMx);
TIM_TimeBaseStructure.TIM_Prescaler = 71; // 定时器分频系数,时钟频率为72MHz,分频系数为71,则定时器时钟频率为1MHz
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseStructure.TIM_Period = 0xFFFF;
TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;
TIM_TimeBaseStructure.TIM_RepetitionCounter = 0;
TIM_TimeBaseInit(TIMx, &TIM_TimeBaseStructure);
TIM_ITConfig(TIMx, TIM_IT_Update, ENABLE);
NVIC_InitTypeDef NVIC_InitStructure;
NVIC_InitStructure.NVIC_IRQChannel = TIMx_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
}
void EXTI_Configuration(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
EXTI_InitTypeDef EXTI_InitStructure;
NVIC_InitTypeDef NVIC_InitStructure;
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_AFIO, ENABLE);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_5;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;
GPIO_Init(GPIOA, &GPIO_InitStructure);
GPIO_EXTILineConfig(GPIO_PortSourceGPIOA, GPIO_PinSource5);
EXTI_InitStructure.EXTI_Line = 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 = EXTI9_5_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
}
int main(void)
{
TIMx_Configuration();
EXTI_Configuration();
while (1)
{
g_frequency = TIM_GetCounter(TIMx) * 1000000 / (g_count * 72);
TIM_SetCounter(TIMx, 0);
}
}
```
代码中使用的是TIM2定时器和PA5引脚,需要根据实际情况进行修改。代码的核心部分是在中断服务程序中对计数器进行操作,并在主函数中根据计数器和定时器的配置计算出频率。
stm32f103c8t6待机模式rtc唤醒demo
根据提供的引用内容,STM32F103C8T6可以通过设置PDDS位来使CPU进入待机模式,并且可以通过CWUF位清除之前的唤醒位。RTC外设是一个掉电后仍然运行的定时器,它具有掉电还继续运行的特性。RTC模块可以提供时钟日历的功能,并且可以通过修改计数器的值来重新设置系统的时间和日期。在设置时间之前,需要取消备份区(BKP)的写保护。
下面是一个STM32F103C8T6待机模式RTC唤醒的示例代码[^1][^2]:
```c
#include "stm32f10x.h"
void RTC_Configuration(void)
{
RCC_APB1PeriphClockCmd(RCC_APB1Periph_PWR | RCC_APB1Periph_BKP, ENABLE);
PWR_BackupAccessCmd(ENABLE);
BKP_DeInit();
RCC_LSEConfig(RCC_LSE_ON);
while (RCC_GetFlagStatus(RCC_FLAG_LSERDY) == RESET) {}
RCC_RTCCLKConfig(RCC_RTCCLKSource_LSE);
RCC_RTCCLKCmd(ENABLE);
RTC_WaitForSynchro();
RTC_WaitForLastTask();
RTC_ITConfig(RTC_IT_ALR, ENABLE);
RTC_WaitForLastTask();
RTC_SetPrescaler(32767);
RTC_WaitForLastTask();
RTC_SetAlarm(RTC_GetCounter() + 10);
RTC_WaitForLastTask();
EXTI_ClearITPendingBit(EXTI_Line17);
EXTI_InitTypeDef EXTI_InitStructure;
EXTI_InitStructure.EXTI_Line = EXTI_Line17;
EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Rising;
EXTI_InitStructure.EXTI_LineCmd = ENABLE;
EXTI_Init(&EXTI_InitStructure);
NVIC_InitTypeDef NVIC_InitStructure;
NVIC_InitStructure.NVIC_IRQChannel = RTC_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
}
void RTC_IRQHandler(void)
{
if (RTC_GetITStatus(RTC_IT_ALR) != RESET)
{
RTC_ClearITPendingBit(RTC_IT_ALR);
// 处理RTC闹钟中断
}
}
int main(void)
{
RTC_Configuration();
while (1)
{
PWR_EnterSTANDBYMode();
}
}
```
这个示例代码中,首先进行了RTC的配置,包括使能PWR和BKP外设时钟,取消备份区写保护,配置LSE时钟源,使能RTC时钟,等待RTC同步,使能RTC闹钟中断,设置RTC预分频器和闹钟时间等。然后,初始化外部中断线和中断向量表,并在主循环中进入待机模式。