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#include"reg51.h"
sbit RS = P3^0;
sbit RW = P3^1;
sbit E  = P3^2;
unsigned int count=0;
unsigned int hour=0,min=0,sec=0;
unsigned char str[]={"0123456789"};
unsigned char str1[]={"Clock:"};
void delay(unsigned int t)
{
	int i=0,j=0;
	for(i=0;i<t;i++)
		for(j=0;j<=100;j++);
}

void writedat(unsigned char dat)  //写入命令
{
	RS= 1;
	RW= 0;
	E = 0;
	P2=dat;
	delay(5);
	E=1;
	E=0; 
}

void writecom(unsigned char com)  //写入命令
{
	RS= 0;
	RW= 0;
	E = 0;
	P2=com;
	delay(5);
	E=1;
	E=0;
	E=1;
}

void display()
{
    int i=0;
	unsigned char temp0=0,temp1=0,temp2=0,temp3=0,temp4=0,temp5=0;
	temp0=hour/10;
	temp1=hour%10;
	temp2=min/10;
	temp3=min%10;
	temp4=sec/10;
	temp5=sec%10;
	writecom(0x80);
	delay(5);
    while(str[i]!='\0')
    {
        writedat(str1[i]);
        delay(5);
        i++;
    }
    writecom(0x80+0x40+4);
	delay(5);
	writedat(str[temp0]);
	delay(5);
	writedat(str[temp1]);
	delay(5);
	writedat(':');
	delay(5);
	writedat(str[temp2]);
	delay(5);
	writedat(str[temp3]);
	delay(5);
	writedat(':');
	delay(5);
	writedat(str[temp4]);
	delay(5);
	writedat(str[temp5]);
	delay(5);
}


void initlcd()  //初始化
{
	writecom(0x38);
	writecom(0x0c);
	writecom(0x06);
	writecom(0x01);
}
void inittimer()
{
	TMOD=0x01;
	TH0=(65536-50000)/256;  
	TL0=(65536-50000)%256;
	ET0=1;
	EA=1;
	TR0=1;
}

void main()
{
	initlcd();
	inittimer();
	while(1)
	{
		display();
	}
}

void timer0_isr() interrupt 1
{
	TH0=(65536-50000)/256; //无法重装载
	TL0=(65536-50000)%256;
	count++;
	if(count==20)
	{
		sec++;
		count=0;
	}
	if(sec==60)
	{
		min++;
		sec=0;
	}
	if(min==60)
	{
		hour++;
		min=0;
	}
	if(hour==24)
	{
		hour=0; 
	}
}