TIM定时中断

TIM简介

定时器类型

基本定时器

通用定时器

高级定时器

基本定时器仅支持向上计数:0->重装值->发起中断

通用定时器和高级定时器支持向上计数,向下计数,中央对齐计数

向下计数:重装值->0->发起中断

中央对齐计数:0->重装值->发起中断->0->发起中断

基本定时器只能使用内部时钟(系统频率)72MHz

通用定时器可以使用内部时钟和外部时钟

定时中断基本结构

预分频器时序

计数器时序

计数器无预装时序

计数器有预装时序

RCC时钟树

定时器中断

接线图

代码

Timer.c

#include "stm32f10x.h"                  // Device header

void Timer_Init(void)
{
	RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2,ENABLE); //使能时钟
	TIM_InternalClockConfig(TIM2); //配置内部时钟
	TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStruct;
	TIM_TimeBaseInitStruct.TIM_ClockDivision=TIM_CKD_DIV1; //时钟分频
	TIM_TimeBaseInitStruct.TIM_CounterMode=TIM_CounterMode_Up; //向上计数
	TIM_TimeBaseInitStruct.TIM_Period=10000-1; //自动重装器
	TIM_TimeBaseInitStruct.TIM_Prescaler=7200-1; //预分频器
	TIM_TimeBaseInitStruct.TIM_RepetitionCounter=0;
	TIM_TimeBaseInit(TIM2,&TIM_TimeBaseInitStruct); //配置时基单元
	
	TIM_ClearFlag(TIM2,TIM_FLAG_Update); //清除中断标志位,防止初始化时就会进一次中断
	
	//中断配置
	TIM_ITConfig(TIM2,TIM_IT_Update,ENABLE); //更新中断
	
	//NVIC配置
	NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);
	NVIC_InitTypeDef NVIC_InitStruct;
	NVIC_InitStruct.NVIC_IRQChannel=TIM2_IRQn;
	NVIC_InitStruct.NVIC_IRQChannelCmd=ENABLE;
	NVIC_InitStruct.NVIC_IRQChannelPreemptionPriority=1;
	NVIC_InitStruct.NVIC_IRQChannelSubPriority=1;
	NVIC_Init(&NVIC_InitStruct);
	//启动定时器
	TIM_Cmd(TIM2,ENABLE);
}

/*
void TIM2_IRQHandler(void)
{
	if(TIM_GetITStatus(TIM2,TIM_IT_Update)==SET)
	{
		
		TIM_ClearITPendingBit(TIM2,TIM_IT_Update);
	}
}
*/

Timer.h

#ifndef __TIMER_H__
#define __TIMER_H__

void Timer_Init(void);

#endif

main.c

#include "stm32f10x.h"                  // Device header
#include "Delay.h"
#include "OLED.h"
#include "Timer.h"

uint16_t Num;

int main(void)
{
	OLED_Init();
	Timer_Init();
	OLED_ShowString(1,1,"Num:");
	while(1)
	{
		OLED_ShowNum(1,5,Num,5);
	}
}

void TIM2_IRQHandler(void)
{
	if(TIM_GetITStatus(TIM2,TIM_IT_Update)==SET)
	{
		Num++;
		TIM_ClearITPendingBit(TIM2,TIM_IT_Update);
	}
}

定时器外部时钟

接线图

原理图

代码

Timer.c

#include "stm32f10x.h"                  // Device header

void Timer_Init(void)
{
	RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2,ENABLE); //使能时钟
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA,ENABLE);
	GPIO_InitTypeDef GPIO_InitStruct;
	GPIO_InitStruct.GPIO_Mode=GPIO_Mode_IPU;
	GPIO_InitStruct.GPIO_Pin=GPIO_Pin_0;
	GPIO_InitStruct.GPIO_Speed=GPIO_Speed_50MHz;
	GPIO_Init(GPIOA,&GPIO_InitStruct);
	
	TIM_ETRClockMode2Config(TIM2,TIM_ExtTRGPSC_OFF,TIM_ExtTRGPolarity_NonInverted,0); //外部时钟
	TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStruct;
	TIM_TimeBaseInitStruct.TIM_ClockDivision=TIM_CKD_DIV1; //时钟分频
	TIM_TimeBaseInitStruct.TIM_CounterMode=TIM_CounterMode_Up; //向上计数
	TIM_TimeBaseInitStruct.TIM_Period=10-1; //自动重装器
	TIM_TimeBaseInitStruct.TIM_Prescaler=1-1; //预分频器
	TIM_TimeBaseInitStruct.TIM_RepetitionCounter=0;
	TIM_TimeBaseInit(TIM2,&TIM_TimeBaseInitStruct); //配置时基单元
	
	TIM_ClearFlag(TIM2,TIM_FLAG_Update); //清除中断标志位,防止初始化时就会进一次中断
	
	//中断配置
	TIM_ITConfig(TIM2,TIM_IT_Update,ENABLE); //更新中断
	
	//NVIC配置
	NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);
	NVIC_InitTypeDef NVIC_InitStruct;
	NVIC_InitStruct.NVIC_IRQChannel=TIM2_IRQn;
	NVIC_InitStruct.NVIC_IRQChannelCmd=ENABLE;
	NVIC_InitStruct.NVIC_IRQChannelPreemptionPriority=1;
	NVIC_InitStruct.NVIC_IRQChannelSubPriority=1;
	NVIC_Init(&NVIC_InitStruct);
	//启动定时器
	TIM_Cmd(TIM2,ENABLE);
}

uint16_t Timer_GetCounter(void)
{
	return TIM_GetCounter(TIM2);
}

/*
void TIM2_IRQHandler(void)
{
	if(TIM_GetITStatus(TIM2,TIM_IT_Update)==SET)
	{
		
		TIM_ClearITPendingBit(TIM2,TIM_IT_Update);
	}
}
*/

Timer.h

#ifndef __TIMER_H__
#define __TIMER_H__

void Timer_Init(void);
uint16_t Timer_GetCounter(void);

#endif

main.c

#include "stm32f10x.h"                  // Device header
#include "Delay.h"
#include "OLED.h"
#include "Timer.h"

uint16_t Num;

int main(void)
{
	OLED_Init();
	Timer_Init();
	OLED_ShowString(1,1,"Num:");
	OLED_ShowString(2,1,"CNT:");
	while(1)
	{
		OLED_ShowNum(1,5,Num,5);
		OLED_ShowNum(2,5,Timer_GetCounter(),5);
	}
}

void TIM2_IRQHandler(void)
{
	if(TIM_GetITStatus(TIM2,TIM_IT_Update)==SET)
	{
		Num++;
		TIM_ClearITPendingBit(TIM2,TIM_IT_Update);
	}
}