#include "reg52.h"
sbit fei1=P1^1;
unsigned char s[8] ;
unsigned int i; 
uart()
 {

    //for (i=0;i<9;i++)
       if(RI==1)
         {
         RI=0;
         i = SBUF;
         SBUF = 0x4F;
         while (TI==0)
            ;
         TI=0;
         SBUF = 0x4B;
         while (TI==0)
            ;
         TI=0;
        }
    //收數據
   /*if (s[0]==0xaa) 
         {SBUF=0xAA;
          
          }*/
 }

void main(void)
{ 
 TMOD=0X20;
 TH1=0XFD;
 TL1=0XFD;  //波特率9600。定時器1方式2。
 TCON=0x40;        //TCON
 SCON=0X50;    //10位異步收發
 IE=90;
 fei1=1;
while(1)
      {   
       uart();   //串口數據的收發
      }
} 






#include "reg51.h"
unsigned char idata txdata[7]={"hello\n"};

void main()
{ unsigned char i;
  unsigned int  j;
  TMOD=0x20;
  TL1=0xfd;
  TH1=0xfd;
  SCON=0xd8;
  TR1=1;
 while(1)
 { i=0;
     while(txdata[i]!=0x00)
     { SBUF=txdata[i];
       while(TI==0);
       TI=0;
       i++;
     }
    for(j=0;j<10000;j++);
  }
}



#include "reg51.h"
void main(void)
{ unsigned char a;
  TMOD=0x20;
  TL1=0xfd;
  TH1=0xfd;
  SCON=0xd8;
  TR1=1;
  while(1)
  {  while(RI==0);
     a=SBUF;
     SBUF=a;
     while(TI==0);
     TI=0;
  }
}      





#include "reg51.h"
unsigned int i=1; 
uart()
 {
       
       if(i==1)
         {
       
         SBUF =0x42;
         while (TI==0)
            ;
         TI=0;
         SBUF = 0x4B;
         while (TI==0)
            ;
         TI=0;
         i++;
        }
    //收數據
   /*if (s[0]==0xaa) 
         {SBUF=0xAA;
          
          }*/
 }

void main(void)
{ 
 TMOD=0X20;
 TH1=0XFD;
 TL1=0XFD;  //波特率9600。定時器1方式2。
 TCON=0x40;        //TCON
 SCON=0X50;    //10位異步收發
 IE=90;
while(1)
      {   
       uart();   //串口數據的收發
      }
} 




#include "reg52.h"
unsigned int i; 
void main(void)
{ unsigned char  flag=0;
 unsigned char ch;
 TMOD=0x20;
 TH1=0xFd;
 TL1=0XFd;  //波特率9600。定時器1方式2。
 TR1=1; 
 SCON=0x50;    //10位異步收發
while(1)
      {   
      if(RI==1){
        RI=0;
        ch=SBUF;
        flag=1;
      }
     if(flag==1){
        SBUF=ch;
        while(!TI);
        TI=0;
        flag=0;
        
     }
     
      }
}