CCS/MSP430FR5969: How to write the ISR for TimerA1 module?

Tool/software: Code Composer Studio

Hello everyone,

I'm trying to use the grove ultrasonic ranger for some distance measurement.

The plan is to send out a pulse of 10us and capture the high-time of the echo from the sensor and then calculate the distance.

However it seems that i can't get into the ISR (which i copied from one of the example code file of TA1). Im already using TA0 for some other job and therefore have to use TA1:

I configured TA1 in capture mode and on P1.2 (which is the Timer 1 CCR1 register according to the datasheet) I'm waiting to recieve to echo signal and trigger the ISR:

#include <msp430.h>
#include "stdint.h"
#include <string.h>
#include <stdlib.h>


unsigned int counter;
unsigned int distance_cm;

// Timer A1 interrupt service routine
#if defined(__TI_COMPILER_VERSION__) || defined(__IAR_SYSTEMS_ICC__)
#pragma vector = TIMER1_A0_VECTOR
__interrupt void Timer1_A0_ISR(void)
#elif defined(__GNUC__)
void __attribute__ ((interrupt(TIMER1_A0_VECTOR))) Timer1_A0_ISR (void)
#else
#error Compiler not supported!
#endif
{
    if (TA1CCTL1 & CCI)            // Rising edge
        {
            counter = TA1CCR1;      // Copy counter value to variable
        }
        else                        // Falling edge
        {
            // Formula: Distance in cm = (Time in uSec)/58
            distance_cm = (TA1CCR1 - counter)/58;
        }
        TA1CCTL1 &= ~CCIFG;           // Clear interrupt flag - handled
}

// Clock System Setup
void clock_init(){

      CSCTL0_H = CSKEY >> 8;                    // Unlock CS registers
      CSCTL1 = DCOFSEL_0;                       // Set DCO to 1MHz
      CSCTL2 = SELA__VLOCLK | SELS__DCOCLK | SELM__DCOCLK;  // Set SMCLK = MCLK = DCO
                                                // ACLK = VLOCLK
      CSCTL3 = DIVA__1 | DIVS__1 | DIVM__1;     // Set all dividers to 1
      CSCTL0_H = 0;                             // Lock CS registers
    }

//timer1A setup
void timer_init(){

    TA1CTL = TASSEL_2 | MC_2 ;          // SMCLK, cont. mode
    TA1CCTL1 = CM_3 | SCS | CAP | CCIE; //capture on rising&falling edge, synchronize CCI1A with clock,
                                        // capture mode, capture interrupt enable
    }

void peripherals_init(){

    P1DIR |= BIT3;                   //set output for trigger
    P1DIR &= ~BIT2;                  //set input for echo
    P1SEL0 |= BIT2;                  //configure P1.2 as capture input (CCI1A) for TimerA1
    P1SEL1 &= ~BIT2;

   }

void main (void){
   WDTCTL = WDTPW | WDTHOLD;      //Stop Watchdog Timer
   PM5CTL0 &= ~LOCKLPM5;          // This is Needed for MSP430FR5969!

   clock_init();
   timer_init();
   peripherals_init();
   init_UART();

   P1OUT &= ~BIT3;                  //keep trigger low

// Welcome String over UART
   send_str("Ultrasonic Distance Measurement in cm: ");

   __bis_SR_register(GIE);


   while (1)
       {
           // measuring the distance
           P1OUT ^= BIT3;                      // trigger high
           __delay_cycles(10);                  // 10us wide
           P1OUT ^= BIT3;                       // trigger low
           __delay_cycles(500000);              // 0.5sec measurement cycle

       }
}