Interface Bluetooth HC-05 with 89S52

#include<regx51.h>

char num[4]={"000"};

void main()
{
TMOD=0x20;            //Choosing Timer mode
TH1=0xFD;             //Selecting Baud Rate
SCON=0x50;            //Serial mode selection
TR1=1;
IE=0x90;             //Enabling Serial Interrupt
while(1);
}
void ser_intr(void)interrupt 4
{
unsigned int i;        //Subroutine for Interrupt
IE=0x00;

for(i=0;i<=2;i++)     //Transmitting data
{
SBUF=num[i];
while(TI==0);
TI=0;
}
IE=0x90;
}