//程序：
//晶振：11.0592MHz
#include
<AT89X52.h> unsigned char code
seg8[16]={0xc0,0xf9,0xa4,0xb0,0x99,0x92,0x82,0xf8,0x80,0x90,0x88,0x83,0xc6,0xa1,0x86,0x8e};
unsigned
int number=1970;
unsigned int interval=0;
unsigned char point=0;
//小数点的位置（从左数） sbit LED1=P2^7;
sbit LED2=P2^6;
sbit LED3=P2^5;
sbit
LED4=P2^4; //延迟n毫秒
void delay(unsigned int n)
{
while
(n--)
{
TH2=0xfc;
TL2=0x66; //11.0592MHz
//TL2=0x18;
//12MHz
TF2=0;
TR2=1;
while (TF2==0);
TF2=0;
}
} void
display_seg8()
{
bit display_zero=0; //是否是最高位的0
LED1=1;
if (point!=1
&& display_zero==0 &&
number/1000==0)
P0=0x00;
else
{
P0=~seg8[number/1000]+(point==1)*0x80;
display_zero=1;
}
delay(3);
P0=0x00;
LED1=0;
LED2=1;
if (point!=2 && display_zero==0 &&
number%1000/100==0)
P0=0x00;
else
{
P0=~seg8[number%1000/100]+(point==2)*0x80;
display_zero=1;
}
delay(3);
P0=0x00;
LED2=0;
LED3=1;
if (point!=3 && display_zero==0 &&
number%100/10==0)
P0=0x00;
else
{
P0=~seg8[number%100/10]+(point==3)*0x80;
display_zero=1;
}
delay(3);
P0=0x00;
LED3=0;
LED4=1;
P0=~seg8[number%10]+(point==4)*0x80;
//末尾的0始终显示
delay(3);
P0=0x00;
LED4=0;
} void main()
{
EA=1;
//开总中断
TMOD=0x02; //定时器0为8位自动重装工作方式
//TL0=TH0=0x06;
//定时0.25ms
TL0=TH0=0x19; //11.0592MHz晶振下定时0.25ms
ET0=1; //开定时器中断
TR0=1;
//开定时器 T2MOD=0x01; //定时器2工作于16位查询工作方式
TR2=0; P2=0x00;
while
(1)
display_seg8();
} void et0() interrupt
1
{
//4次为1ms，4000次为1s
interval++;
if
(interval>=4000)
{
interval=0;
number++;
if
(number>9999)
number=0;
}
}