Em 16/2/2010 02:39, Scott Dattalo escreveu:
> Isaac Marino Bavaresco wrote:
>
>   =

>> 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.
>>     =

> It's been a while since I looked at this stuff, but 10 years ago we came
> up with an efficient PIC-based algorithm. I think Nikolai's 16-bit version
> can be truncated to 9-bits. This takes 38 cycles (and 38 instructions) for
> a 9-bit binary to packed BCD.
>
> http://www.piclist.com/tecHREF/microchip/math/radix/b2a-16b3a2-ng.htm
>
> Scott
>   =


Hi Scott,

I already knew the code. I just didn't remember it was so efficient :)

Anyway, for someone learning how to program it is a bit too complicated.

The method I presented although less efficient, can be scaled-up to any
number of digits following the same simple mechanism.

For the people complaining about MPLAB-C18 library efficiency, take a
look at its 'printf' function (vfprintf indeed). It first converts every
value to be printed to 32 bits and extracts each digit by division/module.
I rewrote most of the MPLAB-C18 library to accept my generic pointers
and in the process I optimized the vfprintf function, but I didn't
replace the numeric conversion code yet. Someday I'm going to optimize
it using some routine in the Piclist source code library.


Best regards,

Isaac

__________________________________________________
Fa=E7a liga=E7=F5es para outros computadores com o novo Yahoo! Messenger =

http://br.beta.messenger.yahoo.com/ =


-- =

http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist