单片机交通灯。1红灯亮15秒。2绿灯亮15秒。3黄灯亮并闪烁

#include<reg52.h>
#define uchar unsigned char
#define uint unsigned int
sbit dula=P2^6;
sbit wela=P2^7 ;
sbit key=P3^2 ;
sbit led1= P1^0;
sbit led2= P1^1;
sbit led3= P1^2;
uchar num,num1,pp,num2 ,shi,ge;
uint i,j,k;
uchar code table[]={0x3f,0x06,0x5b,0x4f,
                    0x66,0x6d,0x7d,0x07,
        0x7f,0x6f,0x77,0x7c,
         0x39,0x5e,0x79,0x71};
void delay(uint );
void display(uchar);
void keyscan();
void init();
void main()
{
 init(); 
 led1=0;
 delay(15000);
 led1=1;
 led2=0;
 delay(15000);
 led2=1;
 for(k=0;k<=10;k++)
   {
     led3=0;
   delay(500);
   led3=1;
   delay(500);  
   }
 
 
  display(num)  ;

}
void delay(uint ms)   //延时函数
{
 for(i=ms;i>0;i--)
    for(j=110;j>0;j--);
}
void display(uchar num)   //动态显示函数
{ 
 shi=num/10;
 ge=num%10;
 dula=1 ;
 P0=table[shi];
 dula=0;
 P0=0xff;
 wela=1;
 P0=0xfe;
 wela=0;
 delay(5);

 dula=1 ;
 P0=table[ge];
 dula=0;
 P0=0xff;
 wela=1;
 P0=0xfd;
 wela=0;
 delay(5);
  
}
void keyscan()     //键盘检测函数
{
 if (key==0)
 {
  delay(10);
  if(key==0)
   pp=1;   //判断按键的开关，若为1则表明开始亮灯。
 }
}
void init()      //初始化函数
{
 TMOD=0x01;
 TH0=(65536-45872)/256;
 TL0=(65536-45872)%256;
 EA=1;
 ET0=1;
}
void timer0()interrupt 1  //定时器0中断
{
 TH0=(65536-45872)/256;
 TL0=(65536-45872)%256;
 num2++;
 if(num2==20)
 {
  num2=0;
  num++;
  if(num==15)
     num=0;
 }
}