MSP430F5635 lost in space

I would immediately try some simple LED blink or similar but confirmed to work, code example to see how it behaves comparing to my code. Then look for behavior and code differences until problem with my code found.

You say that you initialize crystals but do not show code. Maybe clock init code causes crash?

Thank you for your prompt reply. I have the clocks coming out on pins and they are just fine. I have programmed this module with some simple code prior to this and it worked okay so I know the hardware works. But here is the clock init code:


void main(void)
{
	WDTCTL = WDTPW + WDTHOLD;                 // Stop WDT

	P1DIR |= BIT0;                            // ACLK set out to pins
	
	P1SEL |= BIT0;
	
	P3DIR |= BIT4;                            // SMCLK set out to pins
	
	P3SEL |= BIT4;

	BAKCTL |= BAKDIS;					//disable battery backup

	while(BAKCTL & LOCKBAK)                    // Unlock XT1 pins for operation
	
		BAKCTL &= ~(LOCKBAK);
	
	  P7SEL |= BIT2+BIT3;                       // Port select XT2

  UCSCTL6 &= ~(XT1OFF);                     // XT1 On

  UCSCTL6 |= XCAP_3;                        // Internal load cap

  // Loop until XT1 fault flag is cleared

 		  UCSCTL3 = SELREF_2;		//set DCO reference = 
		  UCSCTL4 = SELA_0 | SELS_3 | SELM_3;			//set ACLK = xt1
		  UCSCTL5 = DIVS_2;
		  UCSCTL6 &= ~(XT2OFF + XT1OFF);
		  UCSCTL6 |= XCAP_3;
		  UCSCTL0 = 0x0000;			//set lowest possible DCOx, MODx
		
		  //loop 'til stable
		  do
		  {
			UCSCTL7 &= ~(XT2OFFG + XT1LFOFFG + DCOFFG);
			SFRIFG1 &= ~OFIFG;
                        __no_operation();
		  }while(SFRIFG1 & OFIFG);
		
		  __bis_SR_register(SCG0);	//disable FLL control loop
		  UCSCTL1 = DCORSEL_6;		//select DCO range 16 Mhz operation
		  UCSCTL2 |= 1;			//set DCO multiplier for 8 Mhz
		  						//(N + 1)*FLLRef = Fdco
		  						//(249 + 1)*32768 = 8 Mhz
		  __bic_SR_register(SCG0);		//enable FLL control loop
		
		  //32*32*8 Mhz = 250000 = MCLK cycles for DCO to settle
		
		  __delay_cycles(250000);

Also here is my timer interrupt code which may fire once or twice before I get lost at the same spot:

void TimerA_init(void)
{
  TA0CTL |= (TASSEL_1 + ID_0 + MC_2); 

  TA0CCR0 = 0x8000;         // 32768
  TA0CCR1 = 1600;           
}


#pragma vector=TIMER0_A0_VECTOR
__interrupt void Timer_A0_ISR (void)
{
  TA0CCR0 += 0x8000;
  heart_beat++;
  sleep_timer++;
 __bic_SR_register(LPM0_bits);
}