Hi everyone

I am trying to use the 16 by 16 bit divide from
http://home.netcom.com/~fastfwd/answers.html#PIC00094. I can not get it
to work. I am passing the upper byte as HVValueH and the lower as
HVValueL to a routine called CalibrateV which calls the divide routine.
The values HV_ValueH, HV_ValueL and the values for the divide routine
are mirrored in all of the memory banks. Here is my code, if you need to
see more of the code let me know.


CalibrateV
;Takes HV_ValueL,HV_ValueH, OffsetV,ConvFacV
;HV_ValueH,HV_ValueL =3D (HV_ValueH,HV_ValueL) +
((HV_ValueH,HV_ValueL)/ConvFacV)+OffsetV
;Now it is only a test routine for multiplication=20
BANK0
MOVF    HV_ValueH,W   ;Puts HV value in Dividen 0x0808
MOVWF   DIVIDENDHI=20
MOVF    HV_ValueL,W
MOVWF   DIVIDENDLO
MOVLW   0x04    =09
MOVWF   DIVISORHI   ;Puts 0x0404 in Divisor
MOVLW   0x04
MOVWF   DIVISORLO
PCALL   DIVIDE16          ;Calls divide
MOVF    QUOTIENTHI,W
MOVWF   HV_ValueH           ;Puts values back in HV_Value to be sent out
MOVF    QUOTIENTLO,W
MOVWF   HV_ValueL
RETURN



DIVIDE16:
;16 bit devide
; Enter with Dividend in DIVIDENDHI:DIVIDENDLO, divisor in
; DIVISORHI:DIVISORLO.
;
; Exits with quotient in QUOTIENTHI:QUOTIENTLO, remainder in
; REMAINDERHI:REMAINDERLO.
        =09
            BANK0=09
            CLRF    REMAINDERHI     ;CLEAR THE REMAINDER.
            CLRF    REMAINDERLO     ;

            MOVLW   16              ;WE'RE DIVIDING BY A 16-BIT DIVISOR.
            MOVWF   COUNT           ;

    DIVLOOP:

            RLF     DIVIDENDLO      ;SHIFT DIVIDEND LEFT 1 BIT INTO
            RLF     DIVIDENDHI      ;REMAINDERHI:REMAINDERLO.
            RLF     REMAINDERLO     ;
            RLF     REMAINDERHI     ;

            MOVF    DIVISORHI,W     ;COMPARE THE DIVISOR TO THE PORTION
OF THE
            SUBWF   REMAINDERHI,W   ;DIVIDEND THAT'S BEEN SHIFTED INTO
REMHI.

            BTFSS   STATUS,Z    =20
            GOTO    CHECKLESS       ;IF THE TWO HI-BYTES AREN'T THE
SAME, JUMP
                                    ;AHEAD.

            MOVF    DIVISORLO,W     ;OTHERWISE, WE HAVE TO COMPARE THE
            SUBWF   REMAINDERLO,W   ;LO-BYTES.

    CHECKLESS:
   =20
            BTFSS   STATUS,C    =20
            GOTO    NOSUB           ;IF THE SHIFTED PORTION OF THE
DIVIDEND WAS
                                    ;LESS THAN THE DIVISOR, JUMP AHEAD.

            MOVF    DIVISORLO,W     ;OTHERWISE, REMAINDER =3D REMAINDER =
-
DIVISOR.
            SUBWF   REMAINDERLO     ;
            MOVF    DIVISORHI,W     ;
            BTFSS   STATUS,C                    ;
            INCFSZ  DIVISORHI       ;
            SUBWF   REMAINDERHI     ; (CARRY'S ALWAYS SET AT THIS
POINT.)

    NOSUB:
   =20
            RLF     QUOTIENTLO      ;IF WE JUST SUBTRACTED, SHIFT A "1"
INTO
            RLF     QUOTIENTHI      ;THE QUOTIENT.  OTHERWISE, SHIFT A
"0".

            DECFSZ  COUNT           ;HAVE WE SHIFTED ENOUGH BITS?
            GOTO    DIVLOOP         ;IF NOT, LOOP BACK.
            RETURN
    ; AT THIS POINT, THE QUOTIENT IS IN QUOTIENTHI:LO AND THE REMAINDER
IS
    ; IN REMAINDERHI:LO

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