交通灯程序 用keilc 编写的

 #include "reg51.h"

   unsigned char code  led[]={0xc0,0xf9,0xa4,0xb0,0x99,0x92,0x82,0xf8,0x80,0x90,0};//共阳极段码表
   unsigned char t[]={17,15,2};//红24s绿15s黄2s
   unsigned char data dis_buf[4]; //数据缓冲区
   unsigned int time=6800;//一个周期中断8200次，每次中断是5 MS；
   unsigned char numd,numn,td,tn;
   bit flash_d,flash_n;
   

   /*东西*/
   sbit dy=P3^0;//黄
   sbit db=P3^1;//绿
   sbit dr=P3^2;//红

  /*南北*/
   sbit nr=P3^5; //红
   sbit nb=P3^6; //绿
   sbit ny=P3^7; //黄

  void  display()
  {
    static unsigned char i=0;
P1=0xff;   
    P1=led[dis_buf[i]];
    P2=1<<i;
i++;
if(i>3)
{
   i=0;