On Mon, 15 Feb 2010, Isaac Marino Bavaresco wrote:

> Em 15/2/2010 10:35, Isaac Marino Bavaresco escreveu:
> > There is an interesting implementation which is used by MPLAB-C18
> > library (file itobcd.asm).
> > It is a very efficient serialized method, it uses only shifts and adds.
> > It is worthy a try.
> >
> > Best regards,
> >
> > Isaac
> >   
> 
> Attached is an implementation in assembly language for mid-range (14-bit
> instructions) PICs.
> The conversion routine takes 34 program words and runs (always) in 207
> instruction cycles.
> 
> Best regards,
> 
> Isaac
> 

Interesting, thank you for sharing that. I haven't worked my way through 
it but it feels good. I'll have to work my may through it in detail :-)

With regards to optimisation, have you considered changing:

BIN2BCD9Bits:   movlw   0x01            ; Mask out the 7 higher bits of the value
                andwf   BinValue+1,f

                bcf     STATUS,C        ; Here we add a twist to allow 9bit conversion
                rrf     BinValue+1,f    ; Instead of pre-shifting left 7times, we rotate
                rrf     BinValue+0,f    ; right once an will use the bytes in reversed order.
                rrf     BinValue+1,f

to

BIN2BCD9Bits:                           ; Mask out the 7 higher bits of the value
                rrf     BinValue+1,f    ; Instead of pre-shifting left 7times, we rotate
                rrf     BinValue+0,f    ; right once an will use the bytes in reversed order.
                clrf    BinValue+1
                rrf     BinValue+1,f


Regards
Sergio Masci
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