void main(void)
{
    WDTCTL = WDTPW | WDTHOLD;// stop watchdog timer
    P1DIR |= 0x01;           // configure P1.0 as output

    volatile unsigned int i; // volatile to prevent optimization

    while(1)
    {
        P1OUT ^= BIT0;      //toggle P1.0
        for(i=10000; i>0; i--); // delay
    }
}