#include <msp430.h> 


/**
 * main.c
 */

int freq[4] =  {0, 128, 256, 512}; // off, 1KHz, 2 KHz, 4 Khz
int main(void)
{
    WDTCTL = WDT_ADLY_1000;          // 1 s interval
    _EINT();                      // Enable interrupts
    IE1 |= WDTIE;                 // Enable WDT interrupt
    P2SEL |= BIT2;                // P2.2 special function (TB0 output)
    P2SEL &= ~BIT1;               // Clear P2.1
    P2OUT &= ~(BIT1+BIT2);        // Turn Off LED1
    TB0CTL = TBSSEL_1 + MC_1;     // Upmode
    P3SEL |= 0x20;                // P3.5 as special function
    P3DIR |= 0x20;                // P3.5 as digital output
    TB0CCTL4 = OUTMOD_4;         // TB4 output is in toggle mode
    TB0CCTL0 = freq[0];
    _BIS_SR(LPM3_bits + GIE);     // Enter Low Power Mode 3
}


// Watchdog Timer interrupt service routine
#pragma vector=WDT_VECTOR
__interrupt void watchdog_timer(void)
{
    static int i =0;
    i++;

    if(i == 1){
        TB0CCTL0= freq[0];            // f = 4 MHz
        P2OUT &=~ BIT1;                // Turn on LED2
        P2OUT &= ~BIT2;               // Turn Off LED1
    }
    else if(i == 2){
        TB0CCTL0= freq[2];            // f = 2 MHz
        P2OUT &= BIT1;                // Turn on LED2
        P2OUT |= BIT2;               // Turn Off LED1
    }
    else if(i == 3){
       TB0CCTL0= freq[3];            // f = 4 MHz
       P2OUT |= BIT1;                // Turn on LED2
       P2OUT |= BIT2;               // Turn Off LED1
    }
       else if(i == 4){
           TB0CCTL0= freq[1];            // f = 4 MHz
           P2OUT &=~ BIT1;                // Turn on LED2
           P2OUT &= ~BIT2;               // Turn Off LED1
           }
       else if(i == 5){
                  TB0CCTL0= freq[3];            // f = 4 MHz
                  P2OUT &=~ BIT1;                // Turn on LED2
                  P2OUT |= BIT2;               // Turn Off LED1
       }
}