Starterware/MSP430FR6972: the question about continous mode of timer

Part Number: MSP430FR6972

Tool/software: Starterware

Hi,sir

I want to restart a new timing in the running timer at continous mode. For example, I set  timer B0.2 500ms timing , I want to stop it and restart a 20ms timing when timer B0.2 is running on the way to 500ms timing . how could I realize the function? I try to do it  as following :

 //timing 23.5ms
 TB0CCTL0 &= ~CCIE;                          
  TB0CCR0 = 2950;
  
 //timing 500ms
  TB0CCTL2 &= ~CCIE;
  TB0CCR2 = 62500;

  //smclk  continuous mode  125kHz
  TB0EX0 = TAIDEX_7;
  TB0CTL = TBSSEL__SMCLK | MC__CONTINUOUS| ID__8; 


  //TB0.2 interrupt
  case TB0IV_TB0CCR2: 
      
          TB0CCR2 += 62500;
                   
          //..
          //..execute some code
          //..
          if(temp1%2)
          {
          //I want to stop running 500ms timing,start a new B0.2 timing to 20ms
          TB0CCTL2 &= ~CCIE;
          TB0CCR2= 2500; 
          TB0CCTL2 |= CCIE;
          }
          break;           

I found this is wrong ,It couldn't to restart a new 20ms timing .please help me solve the problem ,I will appreciate you very much.