Embedded C program code

#include<htc.h>
#define _XTAL_FREQ 20e6
__CONFIG(0x3F3A);
void uart_init()
{
    TRISC6=0;
    TXSTA=0b00100100;    //CHECK THE DATA SHEET FOR TXSTA
    RCSTA=0b10010000;    //SEE THE DATA SHEET FOR RCSTA
    BRGH=0;            //  low baud rate 
    SPBRG=129;      //baud rate 2400
}

void interrupt_enable()
{
    GIE=1;
    PEIE=1;
    RCIE=1;
}

void txd(char write_data)
{
    TXREG = write_data;
    while(!TRMT);
}

void interrupt UART()  //interrupt service routine
{    
    PORTD = RCREG; //simply to get the received ASCII on PORTD
}



main()
{      
        TRISD=0;
        uart_init();
        interrupt_enable();
	txd('W');   
	txd('E');  
	txd('L');    
	txd('C');   
        txd('O');
	txd('M');
	txd('E');  //DISPLAY "WELCOME" at starting 
      
        while(1);    //WAITING FOR INTERRUPT (SEE RESULT ON PORT D)
    
}

__CONFIG(0x3F3A); //here the configuration bits value is 3f3a in hex[CODE]