Post by thread:BCD-->BIN BIN-->BCD

Here is a 16 bit BIN->BCD. I don't know who's the original author but it works fine. ;----------------- Laser Cut Here ------------------------ ;Converts Binary to BCD ;Enter with 16 bit binary in LowByte/HighByte ; ;Exits with 5 digit packed BCD in R0,R1,R2 Bin_2_BCD bcf STATUS,C ; clear carry bit first movlw 10h ; number of bits movwf Count clrf R0 clrf R1 clrf R2 loop16 rlf LowByte rlf HighByte rlf R2 rlf R1 rlf R0 decfsz Count,f goto AdjustDEC return AdjustDEC movlw R2 movwf FSR call AdjustBCD movlw R1 movwf FSR call AdjustBCD movlw R0 movwf FSR call AdjustBCD goto loop16 ; AdjustBCD movlw 3 ; enter with FSR pointing addwf 0,w ; to the BCD digit being shifted movwf TEMP btfsc TEMP,3 movwf 0 movlw 30h addwf 0,w movwf TEMP btfsc TEMP,7 movwf 0 return ;----------------------------------- >Did someone do this routine with the assembly of PIC? > > Miguel. >

Ricardo Seixas wrote: {Quote hidden}> > Here is a 16 bit BIN->BCD. > I don't know who's the original author but it works fine. > > ;----------------- Laser Cut Here ------------------------ > ;Converts Binary to BCD > ;Enter with 16 bit binary in LowByte/HighByte > ; > ;Exits with 5 digit packed BCD in R0,R1,R2 > > Bin_2_BCD bcf STATUS,C ; clear carry bit first > movlw 10h ; number of bits > movwf Count > clrf R0 > clrf R1 > clrf R2 > loop16 > rlf LowByte > rlf HighByte > rlf R2 > rlf R1 > rlf R0 > > decfsz Count,f > goto AdjustDEC > return > > AdjustDEC movlw R2 > movwf FSR > call AdjustBCD > > movlw R1 > movwf FSR > call AdjustBCD > > movlw R0 > movwf FSR > call AdjustBCD > > goto loop16 > ; > > AdjustBCD movlw 3 ; enter with FSR pointing > addwf 0,w ; to the BCD digit being shifted > movwf TEMP > btfsc TEMP,3 > movwf 0 > movlw 30h > addwf 0,w > movwf TEMP > btfsc TEMP,7 > movwf 0 > return > > ;----------------------------------- > > >Did someone do this routine with the assembly of PIC? > > > > Miguel. > > Falou!!! Amigo! Miguel.

On Fri, 17 Oct 1997 08:52:19 -0300 Ricardo Seixas <spam_OUTrseixasTakeThisOuTCICLONE.COM.BR> writes: > Here is a 16 bit BIN->BCD. > I don't know who's the original author but it works fine. [code removed] The routine is in a Microchip app note, though it's probably much older than that. The principle that it uses is to repeatedly multiply the BCD number by 2 (first by 'adjusting' it, then shifting left 1 bit). After the shift, the low bit is taken from the binary number. The first bit shifted into the BCD number is the MSB of the binary number, so it is multiplied by 2 n times. This isn't a bad way to convert to decimal, especially for large numbers. I've rewritten the app note code a little to make it smaller. This code also converts 24-bit numbers, producing an 8 digit result. (2^^24 = 16,777,216). The code below has been tested. It requires use of the indirect addressing system (FSR), a 1 byte loop counter (ii), 3 bytes for the original number (bin..bin+2, LSB first), and 4 bytes for the BCD result (bcd..bcd+3, LSB first). ;--------- ; b2bcd ; Converts a 24-bit binary number to 8 digits of BCD. ; Derived from AN526. ; Input: Number at bin...bin+2 LSB first ; Output: Packed BCD at bcd...bcd+3 LSB first. ; RAM : ii, FSR, 4 bytes at bcd. ; Input number at bin is destroyed. b2bcd movlw d'24' ;Do 24 bits movwf ii clrf bcd+0 ;Clear the result clrf bcd+1 clrf bcd+2 clrf bcd+3 b2bcdl rlf bin+0,f ;Rotate one bit out of left end of bin rlf bin+1,f rlf bin+2,f ; If you want to return with the original value in bin (rather than ; garbage), copy the C bit into the low bit of bin here. ; (Not tested) ;; bcf bin+0,0 ;Assume C=0, ;; skpnc ;if it is, OK ;; bsf bin+0,0 ;otherwise put 1 in. rlf bcd+0,f ;and into the low byte of BCD. rlf bcd+1,f rlf bcd+2,f rlf bcd+3,f decfsz ii,f ;Decrement count goto b2bcd2 ;Not done yet, adjust. retlw 0 b2bcd2 movlw bcd+0 movwf FSR call adjbcd incf FSR,f ;to bcd+1 call adjbcd incf FSR,f call adjbcd incf FSR,f ;Last one. call adjbcd goto b2bcdl ;--------- ; adjbcd adjusts the byte at FSR. Used by b2bcd. ; Rewritten adjbcd. Doesn't require tmp. adjbcd movlw h'33' addwf INDF,f ;Add to low and high nybbles btfsc INDF,3 andlw b'11110000' ;Result >7 . OK btfsc INDF,7 andlw b'00001111' ;Hi > 7 OK. subwf INDF,f ;Result <=7, subtract back. return

I think this is one I posted, based upon the Microchip app note. Andy At 09:13 AM 10/17/97 -0700, you wrote: {Quote hidden}>Ricardo Seixas wrote: >> >> Here is a 16 bit BIN->BCD. >> I don't know who's the original author but it works fine. >> >> ;----------------- Laser Cut Here ------------------------ >> ;Converts Binary to BCD >> ;Enter with 16 bit binary in LowByte/HighByte >> ; >> ;Exits with 5 digit packed BCD in R0,R1,R2 >> >> Bin_2_BCD bcf STATUS,C ; clear carry bit first >> movlw 10h ; number of bits >> movwf Count >> clrf R0 >> clrf R1 >> clrf R2 >> loop16 >> rlf LowByte >> rlf HighByte >> rlf R2 >> rlf R1 >> rlf R0 >> >> decfsz Count,f >> goto AdjustDEC >> return >> >> AdjustDEC movlw R2 >> movwf FSR >> call AdjustBCD >> >> movlw R1 >> movwf FSR >> call AdjustBCD >> >> movlw R0 >> movwf FSR >> call AdjustBCD >> >> goto loop16 >> ; >> >> AdjustBCD movlw 3 ; enter with FSR pointing >> addwf 0,w ; to the BCD digit being shifted >> movwf TEMP >> btfsc TEMP,3 >> movwf 0 >> movlw 30h >> addwf 0,w >> movwf TEMP >> btfsc TEMP,7 >> movwf 0 >> return >> >> ;----------------------------------- >> >> >Did someone do this routine with the assembly of PIC? >> > >> > Miguel. >> > > > >Falou!!! Amigo! > >Miguel. > > ================================================================== Andy Kunz - Statistical Research, Inc. - Westfield, New Jersey USA ==================================================================