hi all,
  having problem with measurement of pulse width.i am generating a 
PWM at P1.2 and loping it back to timer B catpure input pin at P4.2.
need to capture the width.
it is not going to the ISR for timerB

#include  "msp430x13x.h"             
TOP_FRONT EQU   0200h  
TOP_TRAIL EQU   0204h

    ORG     0F000h         

RESET     mov.w   #0A00h,SP
Main      CALL    #INIT                
          mov.b &TOP_FRONT,R6
          mov.b &TOP_TRAIL,R7
          sub.b R6,R7
here      jmp here         
          

INIT    
        mov.w   #WDTPW+WDTHOLD,&WDTCTL        
        mov.w   #TASSEL1+TACLR,&TACTL   ; SMCLK, Clear TAR
        mov.w   #512-1,&CCR0            ; PWM Period 
        mov.w   #OUTMOD_7,&CCTL1        ; CCR1 reset/set
        mov.w   #384,&CCR1              ; CCR1 PWM Duty Cycle
	           
        bis.b   #004h,&P1DIR            
        bis.b   #004h,&P1SEL 
        bic.b   #004h,&P1DIR            
        bis.b   #004h,&P1SEL
        BIC     #CCIFG,&CCTL2 ;CLEAR PENDING INTS
        BIS     
#CCIE+CAP+CM0,&CCTL2 ;ENABLE ;INT/CAP/RISING/SOURCE=PIN            
        bis.w   #MC0,&TACTL             ; Start Timer_A in up mode

        eint 
        ret   

TB2INT:
        BIC #CCIFG,&CCTL2
        BIT #CM0,&CCTL2 
        JZ TTRAIL
        MOV &TBR,&TOP_FRONT 
        XOR #CM1+CM0,&CCTL2 
        RETI
TTRAIL:
        MOV &TBR,&TOP_TRAIL 
        XOR #CM1+CM0,&CCTL2
        RETI
        
        ORG     0FFF2h                   
        DW      TB2INT    
        ORG     0FFFEh                   
        DW      RESET                   
        end