#include <reg51.h>
#define uchar unsigned char
#define uint unsigned int
void uart_init()
{
 TMOD=0x20;
 TH1=0xFD;    
 TL1=0xFD;
 PCON=0x00;
 TR1=1;
 SCON=0x50;
}
 void delay(uint z)
{
 uint x,y;
 for(x=z;x>0;x--)
  for(y=125;y>0;y--); 
} 

void main()
{
 uart_init(); 

 do
 { 
  SBUF=0x01;
 while(TI==0);
 TI=0;
  
 while(RI==0);
 REN=0;
 }  
 while(SBUF!=0x02) ;
 
  
  while(1)
  {
  SBUF=0x07;
  while(TI==0);
  TI=0;
  delay(500) ;
  SBUF=0x00;
  while(TI==0);
  TI=0;
  delay(500) ;
  }




}



 #include <reg51.h>
#define uchar unsigned char
#define uint unsigned int
void uart_init()
{
 TMOD=0x20;
 TH1=0xFD;    
 TL1=0xFD;
 PCON=0x00;
 TR1=1;
  
 SM0=0;      //´®¿Ú·½Ê½1
 SM1=1;
 REN=1;

}

void main()
{
uart_init();
 do
 {
 SBUF=0x02;
 while(TI==0);
 TI=0;
 while(RI==0);
 RI=0; 
 P2=SBUF;
 }  
while(P2!=0x01);

while(1)
{
  
   while(RI==0);
   P1=SBUF;
 RI=0;

}
 
}