2.c

C51 程序练习

//用动态扫描方法和定时器1在数码管的前三位显示出秒表，精确到1%秒，即后两位显示1%秒，一直循环下去

#include<reg52.h> 
#define uint unsigned int   
#define uchar unsigned char 
uchar ge,shi,bai,wela,dula;
//P0位选 P1断选
uint tt;
uchar code table[]={
0x3f,0x06,0x5b,0x4f,
0x66,0x6d,0x7d,0x07,
0x7f,0x6f,0x77,0x7c,
0x39,0x5e,0x79,0x71};
void display(uchar,uchar,uchar); //函数声明
void delay(uint);
void main()
{
	TMOD=0x10;//设置定时器1为工作方式1
	TH1=(65536-10000)/256;
	TL1=(65536-10000)%256;
	EA=1;//开总中断
	ET1=1;//开定时器1中断
	TR1=1;//启动定时器1
	while(1)
	{
		display(bai,shi,ge);
	}
}


void exter0() interrupt 3   // 定时器1中断
{
	TH1=(65536-10000)/256;
	TL1=(65536-10000)%256;
	tt++;
	if(tt==1000)
		tt=0;
	bai=tt/100;
	shi=tt%100/10;
	ge=tt%10;
}

void display(uchar one,uchar two,uchar three)
{

		P1=table[one];   //送段数据
		P0=0xfe;
		delay(5);


		P1=table[two];
		P0=0xfd;
		delay(5);


		P1=table[three];
		P0=0xfb;
		delay(5);
}

void delay(uint z)       //延时子函数
{
	uint x,y;
	for(x=z;x>0;x--)
		for(y=110;y>0;y--);
}