版权声明:本文为博主原创文章,未经博主允许不得转载。 https://blog.csdn.net/wuyuzun/article/details/86558373
前言
- 本博文基于STC89C52RC和Keil5 C51环境开发;
- 如有不足之处还请多多指教;
需要的东西
- 定时器0;
- 管脚P1.0;
代码如下:
#include <STC89C5xRC.H>
#define ENABLE 1
#define DISENABLE 0
typedef unsigned char uchar8;
sbit P1_0 = P1^0;
bit Flag = 0;
/*
占空比的时间计算:
占空比 = 高电平时间 /(高电平时间+低电平时间);
*/
//高电平时间(初始值为:0x02EE,即十进制750)
uchar8 Timer0_TH0_High_Level_Time = 0x02; //定时器0高八位高电平时间;
uchar8 Timer0_TL0_High_Level_Time = 0xEE; //定时器0低八位高电平时间;
//低电平时间(初始值为:0x00FA)
uchar8 Timer0_TH0_Low_Level_Time = 0x00; //定时器0高八位低电平时间;
uchar8 Timer0_TL0_Low_Level_Time = 0cFA; //定时器0低八位低电平时间;
void Time0_Init(void);
void main()
{
Time0_Init();
while(1);
}
/*
定时器的配置:
1.假设单片机晶振频率为12MHz;则定时器累加周期为1us;
2.定时器初值为:高电平溢出时间0x02EE,即十进制750;低电平溢出时间0x00FA,即十进制250;
3.定时器0设置成16位自动重装载工作方式;
*/
void Time0_Init(void)
{
TMOD = 0x01;
TH0 = Timer0_TH0_High_Level_Time; //初始值设置为高电平;
TL0 = Timer0_TL0_High_Level_Time;
TR0 = ENABLE;
ET0 = ENABLE;
EA = ENABLE;
Flag = 0;
P1_0 = 1;
}
void Timer0_IT() interrupt 1
{
if(Flag)
{
TH0 = Timer0_TH0_High_Level_Time;
TL0 = Timer0_TL0_High_Level_Time;
Flag = 0;
P1_0 = 1;
}
else
{
TH0 = Timer0_TH0_Low_Level_Time;
TL0 = Timer0_TL0_Low_Level_Time;
Flag = 1;
P1_0 = 0;
}
}