8051 - Eco UART Silabs

//*******************************************************
// Sample echo program for UART0.
//*******************************************************
#include C8051F120.h
typedef unsigned char uchar;
//*******************************************************
// Globals
//*******************************************************
uchar character;
bit charready, stopped;
sbit LED = P1^6;
int count = 0;
//*******************************************************
// config
// Configure the UART and start the interrupt timer.
//*******************************************************
void config(){
    int n;
    SFRPAGE = CONFIG_PAGE;
    WDTCN = 0x07;                   // watchdog timer control
    WDTCN = 0xDE;                   // disable wdt
    WDTCN = 0xAD;
    XBR0 = 0x04;                    // UART0 connects
    XBR2 = 0x40;                    // enable crossbar
    P0MDOUT = 0x01;                 // P0.0 is push-pull TX output
    P1MDIN = 0xFF;                  // input config for P1
                                    // P0.0 = UART TX0 (push-pull output/input)
                                    // P0.1 = UART RX0 (open-drain output/input)
    P1MDOUT |= 0x40;                // enable onboard LED
    OSCXCN = 0x77;                  // external oscillator
    for(n=0;n<3000;n++);            // startup interval
    while((OSCXCN&0x80)==0);        // wait for oscillator
    SCON0 = 0x50;                   // serial port control
    SCON0 &= 0xFC;                  // clear pending interrupt flags
    CKCON = 0x08;                   // clock control
    SFRPAGE = TIMER01_PAGE;
    TH1 = 0xDC;                     // Timer1 UART clock
    TL1 = 0x00;
    TMOD = 0x20;                    // Timer mode register
    TCON = 0x40;                    // Timer control register
    SFRPAGE = LEGACY_PAGE;
    IE = 0x90;                      // Interrupt enable
}
//*******************************************************
// initializeUART
// Initialize the UART and set flags.
//*******************************************************
void initializeUART(){
    charready=0;
    stopped=1;
    config();
    LED = 0;
}
//*******************************************************
// UART0int
// UART0 interrupt routine.
//*******************************************************
void UART0int() interrupt 4 using 1 {
    LED=1;
    if(RI0==1){
        character=SBUF0;
        charready=1;
        if(stopped){
            TI0=1;
            stopped=0;
        }
        RI0=0;
    }
    if(TI0==1){
        if(charready){
            SBUF0=character;
            charready=0;
        }else{
            stopped=1;
        }
        TI0=0;
    }
}
//*******************************************************
// main
//*******************************************************
void main(){
    initializeUART();
    for (; / {
    // count++;
    // if (!count)
    // LED = ~LED;
    }
}