51单片机计时器问题

51单片机计时器问题：我想设置计时器计时在数码管显示的同时pwm控制led灯亮，但是只有数码管显示，led灯不亮，请问应该怎么修改啊

#include

#define uchar unsigned char

sbit dula=P2^6;
sbit wela=P2^7;
sbit beep=P2^3;
sbit S2=P3^0;
sbit S3=P3^1;
sbit LED1 =P1^3;
uchar time = 0;
unsigned char halt,j,k,a1,a0,b1,b0,c1,c0,hour,minute,second,n=255;
unsigned int pp;
unsigned char code table[]={0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,
                        0x07,0x7f,0x6f,0x77,0x7c,0x39,0x5e,0x79,0x71};

void delay(unsigned char i)//延时函数
{
  for(j=i;j>0;j--);
}

void display(uchar shi2,uchar shi1,uchar fen2,uchar fen1,uchar miao2,uchar miao1)//数码管显示
{
   dula=0;
   P0=table[shi2];
   dula=1;
   dula=0;
   
   wela=0;
   P0=0xfe;
   wela=1;
   wela=0;
   delay(5);
   
   P0=table[shi1]|0x80;
   dula=1;
   dula=0;
   
   P0=0xfd;
   wela=1;
   wela=0;
   delay(5);

   P0=table[fen2];
   dula=1;
   dula=0;
   
   P0=0xfb;
   wela=1;
   wela=0;
   delay(5);
   
   P0=table[fen1]|0x80;
   dula=1;
   dula=0;
   
   P0=0xf7;
   wela=1;
   wela=0;
   delay(5);
   
   P0=table[miao2];
   dula=1;
   dula=0;
   
   P0=0xef;
   wela=1;
   wela=0;
   delay(5);
   
   P0=table[miao1];
   dula=1;
   dula=0;
   
   P0=0xdf;
   wela=1;
   wela=0;
   delay(5);
}
void time0init()//定时器初始化
{
    TMOD=0x01;
    TR0=1;
    TH0=(65536-46080)/256;
    TL0=(65536-46080)%256;//46080=50000*11.0592/12
    ET0=1;
    EA=1;
}

void keyscan()//按键控制中断
{
    if(S2==0)
        delay(10);
    if(S2==0)
    {
        halt=1;
        while (!S2);
    }
    if(S3==0)
    {
        delay (10);
        halt=0;
        while (!S3);
    }
}

void  jishi ()//计时
{
    while(1)
    {    
        keyscan();
        if(halt==0)
        {
        TR0=1;
        if(pp==20)
        {    
            pp=0;
            second++;
        
            if(second==60)
            {
                second=0;
                minute++;
                if(minute==60)
                {
                    minute=0;
                    hour++;
                    if(hour==99)
                    {
                        hour=0;
                    }
                }
            }
        }
        
        a0=hour%10;
        a1=hour/10;
        b0=minute%10;
        b1=minute/10;
        c0=second%10;
        c1=second/10;
        display(a1,a0,b1,b0,c1,c0);
    }
    else 
    TR0=0;
    display(a1,a0,b1,b0,c1,c0);
    }
}

void main()
{
    while (1)
    {
            uchar x,y;
            time0init();
            jishi ();
        for (x=0;x<50;x++)//pwm控制led灯
                {
                    for (y=15;y>0;y--)
                    {
                        LED1=0;
                        delay(x);
                        LED1=1;
                        delay(50-x);
                    }
                }
            for (x=50;x>0;x--)
                {
                    for (y=15;y>0;y--)
                    {
                            LED1=0;
                        delay(x);
                        LED1=1;
                        delay(50-x);
                    }
                }
        
        
    }
    
}

void time0() interrupt 1//定时器中断
{
    TH0=(65536-46080)/256;
    TL0=(65536-46080)%256;
    pp++;
    

}