BoostC Macro Help

clock   equ     8               ; 4, 8, 12, 16, 20 MHz, etc.
usecs   equ     clock/4         ; cycles per usec multiplier
tStep   equ     1*usecs         ; cycles per BAM step (1T)
;
;  in-line fixed delay macro, 0..1027 cycles, 14 bit core
;
inDlyCy macro   delay           ; generates 0 to 6 instructions
        local   loop
     if delay > 3
        movlw   delay/4-1       ;
loop    addlw   -1              ; borrow?  (4 cycle loop)
        bc      loop            ; no, branch, else, fall thru'
     endif
     if delay%4 >= 2
        goto    $+1             ; delay%4 == 2 or delay%4 == 3
     endif
     if delay%4 & 1
        nop                     ; delay%4 == 1 or delay%4 == 3
     endif
        endm

/**********************************************
 *  1-usec BAM step size (1T)                 *
 **********************************************/

void interrupt()
{ pir1.TMR2IF = 0;       // clear Timer 2 interrupt flag
  porta = colsel;        // select new column
  portb = bdat[0];       // 2^0 (1T) data
  inDlyCy(1*tstep-2);    // 2^0 (1T) delay
  portb = bdat[1];       // 2^1 (2T) data
  inDlyCy(2*tstep-2);    // 2^1 (2T) delay
  portb = bdat[2];       // 2^2 (4T) data
  inDlyCy(4*tstep-2);    // 2^2 (4T) delay
  portb = bdat[3];       // 2^3 (8T) data
  inDlyCy(8*tstep-2);    // 2^3 (8T) delay
  ...
}