请问进不了T0定时器内部中断是什么原因，芯片是STC15F2K60S2

#include
#include
#include
unsigned char code LEDchar[]={0xC0,0xF9,0xa4,0xb0,0x99,0x92,0x82,0xf8,0x80,0x90,0x88,0x83,0xc6,0xa1,0x86,0x8e};
unsigned char come[] = {0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff};
***it ds1302_ck = P1^7;
***it ds1302_io = P2^3;
***it ds1302_ce = P1^3;
bit flag200ms = 0;
//unsigned char T0RH = 0,T0RL = 0;
void delay(unsigned int t)
{
do{
_nop_();
_nop_();
_nop_();
_nop_();
_nop_();
_nop_();
_nop_();
_nop_();
}while(--t);
}
void dsiplay()
{
unsigned char i,j;
j = 0x80;
for(i=0;i<8;i++)
{
   P2 = 0xE0;
      P0 = LEDchar[come];
      P2 = 0xC0;
      P0 = j;
      j>>=1;
      delay(100);
}
}
void ds1302bytewrite(unsigned char dat)
{
unsigned char mask;
for(mask=0x01;mask!=0;mask<<=1)
{
   if((mask&dat)==0)
         ds1302_io = 0;
      else
         ds1302_io = 1;
   ds1302_ck = 1;
      ds1302_ck = 0;
}
ds1302_io = 1;
}
unsigned char ds1302byteread()
{
unsigned char mask;
unsigned char dat = 0;
for(mask=0x01;mask!=0;mask<<=1)
{
   if(ds1302_io!=0)
      {
         dat |= mask;
      }
      ds1302_ck = 1;
      ds1302_ck = 0;
}
//ds1302_io = 1;
return dat;
}
void ds1302singlewrite(unsigned char reg,unsigned char dat)
{
ds1302_ce = 1;
ds1302bytewrite((reg<<1)|0x80);
ds1302bytewrite(dat);
ds1302_ce = 0;
}
unsigned char ds1302singleread(unsigned char reg)
{
   unsigned char dat;
   ds1302_ce = 1;
      ds1302bytewrite((reg<<1)|0x81);
      dat = ds1302byteread();
      ds1302_ce = 0;
      return dat;
}
void initds1302()
{
unsigned char i;
      unsigned char code inittime[] = {0x48,0x58,0x47};
      ds1302_ce = 0;
      ds1302_ck = 0;
      i = ds1302singleread(0);
      if((i & 0x80)!=0)
      {
         ds1302singlewrite(7,0x00);
         for(i=0;i<3;i++)
         {
            ds1302singlewrite(i,inittime);
         }
      }
}
void main()
{
unsigned char i;
      unsigned char psec = 0xaa;
      unsigned char time[2];
      unsigned char tmr200ms = 0;

      TMOD = 0x21;
TH0 = 0xFC;
TL0 = 0x67;
      ET0 = 1;
TR0 = 1;
      EA = 1;
      initds1302();
         while(1)
      {
         if(flag200ms==1)
               {
               flag200ms = 0;
            for(i=0;i<3;i++)
               {
                  time = ds1302singleread(i);
               }
      if(psec != time[0])
                     {
                        come[0] = 0x40;
                        come[1] = 0x40;
                        come[2] = time[0]&0x0f;
                        come[3] = time[0]>>4;
                        come[4] = time[1]&0x0f;
                        come[5] = time[1]>>4;
                        come[6] = time[2]&0x0f;
                        come[7] = time[2]>>4;
                        dsiplay();
                        psec = time[0];
                        }
      }
               }
}
void interrupttime() interrupt 1
{
static unsigned char tmr200ms = 0;
      TH0 = 0xFC;
      TL0 = 0x67;
      tmr200ms++;
      if(tmr200ms >= 200)
      {
         tmr200ms = 0;
         flag200ms = 1;
      }

}