11_定时器
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;
}
}
}
}
}