定时器原理-定时器定时中断&定时器外部时钟

定时器简介

TIM（Timer）定时器

定时器可以对输入的时钟进行计数，并在计数值达到设定值时触发中断

16位计数器、预分频器、自动重装寄存器的时基单元，在72MHz计数时钟下可以实现最大59.65s的定时

不仅具备基本的定时中断功能，而且还包含内外时钟源选择、输入捕获、输出比较、编码器接口、主从触发模式等多种功能

根据复杂度和应用场景分为了高级定时器、通用定时器、基本定时器三种类型 

定时器类型

stm32f103zet6拥有八个定时器TIM1-TIM8

定时器结构

 高级定时器

 通用定时器

 基本定时器

 定时器中断基本结构

定时器定时中断实验 

Timer.c

#include "stm32f10x.h"                

void Timer_Init(void)
{
	RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);//时钟使能
	
	TIM_InternalClockConfig(TIM2);//内部时钟
	
	TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStructure;
	TIM_TimeBaseInitStructure.TIM_ClockDivision = TIM_CKD_DIV1;//预分频
	TIM_TimeBaseInitStructure.TIM_CounterMode = TIM_CounterMode_Up;//向上计数
	TIM_TimeBaseInitStructure.TIM_Period = 10000 - 1;//arr自动重装器
	TIM_TimeBaseInitStructure.TIM_Prescaler = 7200 - 1;//psc预分频器
	TIM_TimeBaseInitStructure.TIM_RepetitionCounter = 0;//重复计数器
	TIM_TimeBaseInit(TIM2, &TIM_TimeBaseInitStructure);//时基单元初始化
	
	TIM_ClearFlag(TIM2, TIM_FLAG_Update);
	TIM_ITConfig(TIM2, TIM_IT_Update, ENABLE);//使能中断
	
	NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);//优先级配置
	
	NVIC_InitTypeDef NVIC_InitStructure;
	NVIC_InitStructure.NVIC_IRQChannel = TIM2_IRQn;
	NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
	NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 2;
	NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
	NVIC_Init(&NVIC_InitStructure);
	
	TIM_Cmd(TIM2, ENABLE);//运行控制
}

Timer.h

#ifndef __TIMER_H
#define __TIMER_H

void Timer_Init(void);

#endif

main.c

#include "stm32f10x.h"                  
#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

Timer.c 

#include "stm32f10x.h"                 
void Timer_Init(void)
{
	RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);
	
	GPIO_InitTypeDef GPIO_InitStructure;
	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_OD;
	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0;
	GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
	GPIO_Init(GPIOA, &GPIO_InitStructure);
	
	TIM_ETRClockMode2Config(TIM2, TIM_ExtTRGPSC_OFF, TIM_ExtTRGPolarity_NonInverted, 0x0F);
	
	TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStructure;
	TIM_TimeBaseInitStructure.TIM_ClockDivision = TIM_CKD_DIV1;
	TIM_TimeBaseInitStructure.TIM_CounterMode = TIM_CounterMode_Up;
	TIM_TimeBaseInitStructure.TIM_Period = 10 - 1;
	TIM_TimeBaseInitStructure.TIM_Prescaler = 1- 1;
	TIM_TimeBaseInitStructure.TIM_RepetitionCounter = 0;
	TIM_TimeBaseInit(TIM2, &TIM_TimeBaseInitStructure);
	
	TIM_ClearFlag(TIM2, TIM_FLAG_Update);
	TIM_ITConfig(TIM2, TIM_IT_Update, ENABLE);
	
	NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);
	
	NVIC_InitTypeDef NVIC_InitStructure;
	NVIC_InitStructure.NVIC_IRQChannel = TIM2_IRQn;
	NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
	NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 2;
	NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
	NVIC_Init(&NVIC_InitStructure);
	
	TIM_Cmd(TIM2, ENABLE);
}

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

Timer.h

#ifndef __TIMER_H
#define __TIMER_H

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

#endif

 main.c

#include "stm32f10x.h"                  
#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);
	}
}