DS89C450

#include<DS89C4xx.h>
#include<stdio.h>


sbit Tsignal = P3^2;                     //Set sbit Tsignal at P3.2
sbit Learn = P2^7;                       //Set sbit Learn at P1.3
unsigned int i;
unsigned int u;
unsigned char p;
unsigned char xdata x[500];
unsigned char xdata y[500];

void tx_port1(unsigned char a)
{
    SBUF1=a;
    while(TI_1==0);
    TI_1=0;
}


void SPort (void)
{
 TMOD = 0x20;
 TH1 = 0xFD;
 SCON0 = 0x50;
 SCON1 = 0x50;
 TR1 = 1;
}



void timer0(void)
{
 TMOD = 0x01;                           //Timer0 , Mode 1
 TH0 = 0xFF;                            //Set timer to count from -35 = FFDDh
 TL0 = 0xDA;                            //Read every 38us.
 TR0 = 1;
 while(TF0==0);                         //Turn on Timer0
 TF0 = 0;                               //Set Flag to 0;
 TR0 = 0;                               //Turn off Timer0
}//end function

void ext_int0(void)interrupt 0    //External Interrupt0
{
 if(Learn==1)
 {

   for(i=0;i<500;i++)                    //Loop for 500 bytes
   {
    timer0();                            //Call timer0 function

     for(u=0;u<8;u++)                    //Bit Shift Loop
   {
     x[i] = x[i] <<1;                    //Left Bit Shift by 1
     p = Tsignal;                        //Store Tsignal to Buffer p
     tx_port1(p);
     x[i] |= p;                           //OR Masking of p with x[i]


   }//End Bitshift loop

   }//end 500 bytes for loop
 }//end Learn while loop


 else                       //When Learn button is not pressed, data is stored in y
 {
  for(i=0;i<500;i++)                     //Loop for 500 bytes
  {
   timer0();                             //Call timer0 function

    for(u=0;u<8;u++)
   {
     y[i] = y[i] <<1;                    //Left Shift bit by 1;
     p = Tsignal;                                         //Store Tsignal in buffer p;
     tx_port1(p);
     y[i] |= p;                          //OR masking p with y[i];
   }


  }//end 500bytes for loop
 }//end while loop
}

/********************MAIN********************/
void main(void)
{
 SPort();
 PMR=1;
 Learn = 0;
 EA = 1;                                         //Enable Edge Trigger Interrupt
 EX0 = 1;
 IT0 = 1;



}//end main