Electronic – Why do programs stop watchdog timer on MSP430

My suggestion would be get rid of the delay function and use the built in if you are using IAR or CCS."__delay_cycles (cycles);" using the built ins, will give you more predicable results and better timing. You could probably just replace your delay for the built in, to get closer to the results you are looking for.

personally I would go about the whole thing using interrupts and timers to pull the whole thing off and use the peripherals that the msp430 has. I would suggest using the WDT as an interval timer, doing this would leave the other timer for your motor control. p1.3 is used as the wake up pin and p1.0 is the led pin.

example code

volatile int counter;
void main(void) {
    WDTCTL = WDTPW + WDTHOLD;                 // Stop watchdog timer
    P1DIR = 0x01;                             // P1.0 output, else input
    P1OUT =  BIT3;                            // P1.3 set, else reset
    P1REN |= BIT3;                            // P1.3 pullup
    P1IE |= BIT3;                             // P1.3 interrupt enabled
    P1IES |= BIT3;                            // P1.3 Hi/lo edge
    P1IFG &= ~BIT3;                           // P1.3 IFG cleared
    _BIS_SR(GIE);
}
// Port 1 interrupt service routine
#pragma vector=PORT1_VECTOR
__interrupt void Port_1(void)
{
    WDTCTL = WDT_MDLY_64; //enables intervals of 64mS
    IE1 |= WDTIE;  // set WDT interrupt
}
#pragma vector=WDT_VECTOR
__interrupt void watchdog_timer (void)
{
    ++counter;
    P1OUT |= BIT0;
    if (counter == 245) {  //245 x 64mS = 15.6 seconds
        P1OUT &= ~BIT0;
        WDTCTL = WDTPW + WDTHOLD; 
    }
}

Not complete nor has this code been tested, but it should turn the led on for 15 seconds every time the P1.3 button is pushed.

I would expect that several factors will put constrains on the size of the pull up resistor:

1. It must be big enough such JTAG driving circuit (programmer/debugger) will be able to override it,
2. It must be small enough that leakage current/noise will not change logic value of the line,
3. The RC constant that remove /RST after supply ramp up will have to be chosen to ensure proper reset.

Check documentation of uC and JTAG programmer for leakage and drive strength. Based on that size your pull up resistor. I would try to keep RC constant the same which would mean re-sizing capacitor. Note however that schematic you posted put maximum restriction on the capacitor to 2.2nF.

Standard disclaimer: You should follow manufacturer recommendation. There is good reason for that as good gals and guys that made the chip may have put really strange things into it (that are just waiting to bite you). What is worst such things may not be documented as describing them would reveal trade secret. If needed contact your support channel (usually not possible for small customers or DIYers - in this case experiment!). Note that I am not affiliated with TI and I do not have "inside" knowledge of the device.