定时器

定时器介绍

STC89C52定时器资源

定时器框图

定时器工作模式

定时器时钟

中断系统

中断程序流程

STC89C52中断资源

定时器和中断系统

定时器相关寄存器

使用定时器0每隔一秒使LED亮灭

Timer0.c

#include <REGX52.H>

/**
* @brief 定时器0初始化,1毫秒@12.000MHz
  * @param 无
  * @retval 无
  */
void Timer0_Init(void)
{
	TMOD &= 0xF0;			//设置定时器模式
	TMOD |= 0x01;			//设置定时器模式
	TL0 = 0x18;				//设置定时初始值
	TH0 = 0xFC;				//设置定时初始值
	TF0 = 0;				//清除TF0标志
	TR0 = 1;				//定时器0开始计时
	ET0=1;
	EA=1;
	PT0=0;
}

/* 定时器中断函数模板
void Timer0_Routine() interrupt 1
{
	static unsigned int T0Count;
	TL0 = 0x18;
	TH0 = 0xFC;
	T0Count++;
	if(T0Count>=1000)
	{
		T0Count=0;
		
	}
}
*/

Timer0.h

#ifndef __TIMER0_H__
#define __TIMER0_H__

void Timer0_Init(void);

#endif

main.c

#include <REGX52.H>
#include "Timer0.h"

void main()
{
	Timer0_Init();
	while(1)
	{
		
	}
}

void Timer0_Routine() interrupt 1
{
	static unsigned int T0Count;
	TL0 = 0x18;
	TH0 = 0xFC;
	T0Count++;
	if(T0Count>=1000)
	{
		T0Count=0;
		P2_0=~P2_0;
	}
}

运行效果

使用独立键盘控制流水灯

Key.c

#include <REGX52.H>
#include "Delay.h"

/**
  * @brief 获取独立按键键码
  * @param 无
  * @retval 按下按键的键码,范围:0~4, 无按键按下返回0
  */
unsigned char Key()
{
	unsigned char KeyNumber=0;
	if(P3_1==0){Delay(20);while(P3_1==0);Delay(20);KeyNumber=1;}
	if(P3_0==0){Delay(20);while(P3_0==0);Delay(20);KeyNumber=2;}
	if(P3_2==0){Delay(20);while(P3_2==0);Delay(20);KeyNumber=3;}
	if(P3_3==0){Delay(20);while(P3_3==0);Delay(20);KeyNumber=4;}
	return KeyNumber;
}

Key.h

#ifndef __KEY_H__
#define __KEY_H__

unsigned char Key();

#endif

main.c

#include <REGX52.H>
#include "Timer0.h"
#include "Key.h"
#include <INTRINS.H>

unsigned char KeyNum,LEDMode;

void main()
{
	P2=0xFE;
	Timer0_Init();
	while(1)
	{
		KeyNum=Key();
		if(KeyNum==1)
		{
			LEDMode++;
			if(LEDMode>=2)
				LEDMode=0;
		}
	}
}

void Timer0_Routine() interrupt 1
{
	static unsigned int T0Count;
	TL0 = 0x18;
	TH0 = 0xFC;
	T0Count++;
	if(T0Count>=100)
	{
		T0Count=0;
		if(LEDMode==0)P2=_crol_(P2,1);
		if(LEDMode==1)P2=_cror_(P2,1);
	}
}

运行效果

定时器闹钟

Timer0.c

#include <REGX52.H>

/**
* @brief 定时器0初始化,1毫秒@12.000MHz
  * @param 无
  * @retval 无
  */
void Timer0_Init(void)
{
	TMOD &= 0xF0;			//设置定时器模式
	TMOD |= 0x01;			//设置定时器模式
	TL0 = 0x18;				//设置定时初始值
	TH0 = 0xFC;				//设置定时初始值
	TF0 = 0;				//清除TF0标志
	TR0 = 1;				//定时器0开始计时
	ET0=1;
	EA=1;
	PT0=0;
}

/* 定时器中断函数模板
void Timer0_Routine() interrupt 1
{
	static unsigned int T0Count;
	TL0 = 0x18;
	TH0 = 0xFC;
	T0Count++;
	if(T0Count>=1000)
	{
		T0Count=0;
		
	}
}
*/

Timer0.h

#ifndef __TIMER0_H__
#define __TIMER0_H__

void Timer0_Init(void);

#endif

main.c

#include <REGX52.H>
#include "Delay.h"
#include "LCD1602.h"
#include "Timer0.h"

unsigned char Sec,Min,Hour; //秒分时

void main()
{
	LCD_Init();
	Timer0_Init();
	LCD_ShowString(1,1,"Clock:");
	while(1)
	{
		LCD_ShowNum(2,1,Hour,2);
		LCD_ShowString(2,3,":");
		LCD_ShowNum(2,4,Min,2);
		LCD_ShowString(2,6,":");
		LCD_ShowNum(2,7,Sec,2);
	}
}

void Timer0_Routine() interrupt 1
{
	static unsigned int T0Count;
	TL0 = 0x18;
	TH0 = 0xFC;
	T0Count++;
	if(T0Count>=1000)
	{
		T0Count=0;
		Sec++;
		if(Sec>=60)
		{
			Sec=0;
			Min++;
			if(Min>=60)
			{
				Min=0;
				Hour++;
				if(Hour>=24)
				{
					Hour=0;
				}
			}
			
		}
		
	}
}

运行效果