#include <reg51.h>
void T1M1Delay(void);
void main(void)
  {
    unsigned char x;
    P2=0x55;
    while(1)
      {
        P2=~P2;		
        for(x=0;x<20;x++)
          T1M1Delay();
      }
  }
void T1M1Delay(void)
  {
    TMOD=0x10;		
    TL1=0xFE;		
    TH1=0xA5;		
    TR1=1;			
    while(TF1==0);	
    TR1=0;			
    TF1=0;			
  }