cant not use capture timer interrupt msp430g2553

#define IRout BIT0
int main(void)
{
	WDTCTL = WDTPW + WDTHOLD;                 // Stop WDT
	BCSCTL1 = CALBC1_1MHZ;                    // Set DCO
	DCOCTL = CALDCO_1MHZ;

	P2DIR &= ~IRout;
	P2SEL |= IRout;
	P2SEL2 &= ~IRout;
	
	TA1CCTL0 = CM_2 + CCIS_0 + CAP + CCIE + SCS;		// Capture on falling edge, CCI0A, interrupt Enable
	TA1CTL = TASSEL_2 + MC_2 + TACLR + ID_0;		//

	__bis_SR_register(LPM0_bits+GIE);					// Go to sleep while waiting for trigger
	
	 while (true) {
  }
}
  
  #pragma vector=TIMER1_A0_VECTOR
__interrupt void Timer1A0(void)
{
	__bic_SR_register_on_exit(LPM0_bits);
}

Hi guys,

Below is my program, it's can not detect a falling edge. I set a break point at line "while true", it can not jump to that position.

What I was wrong?

Thank in advance!