OPENCORES.ORG

I'd like to thank everyone who'se offered a suggestion so far.  I think I
forgot to mention a couple of things initially, or I may not have looked
at everthing involved, but the unit I actually need to do is a log adder,
which involves both a log and raising a constant number to -d, where d is
some 32 bit floating point number.  Also, this whole mess has to be 32 bit
floating point (they arn't actaully sure if even 32 bits is enough
precision).  Also, we need to do at least 4200 log-adds in a 10 ms frame.

The good news is that my professor said after I got this done, he'd have
no problem with my putting the log adder on open cores.  I don't know how
useful it'l be to anyone else, but it'l at least be an example of the hard
(but more precise) way of logs.  (We've been told that for this semester
we can trade off as much space for speed as we need, as long as we can
synthesize it for some FPGA, most likley the biggest one the tools support :)

Mike

On Tue, 21 Sep 2004, Lars Segerlund wrote:

>
>  If you want to do it fast you might check out a CORDIC , it's a coordinate rotator algorithm, and I am quite certain that it might do log's as well, ( doen very close to everything :-) ).
>
>  There is one on opencores, with some references.
>
>  Otherwise there always newtons algorithm, ( which can be speed up a bit for a specific function as long as it's monotone), I think it's still the fastest as for square roots, don't know about logs, but I think a codic might be better in hardware.
>
>  / Lars Segerlund.
>
>
> On Mon, 20 Sep 2004 16:41:41 -0400 (EDT)
> Michael M Delaney <mmdst23+@pitt.edu> wrote:
>
> > Can anyone suggest any websites, books, or papers on how a log is actaully
> > calcuated?  So far, I haven't had much luck with google, and after looking
> > at the list archives for the FPU, it seems like it was decided that doing
> > logs and trigs in hardware wasn't worth the time and effort (I could be
> > wrong, I only took a quick glance through the source).
> >
> > Thanks,
> > Mike
> > _______________________________________________
> > http://www.opencores.org/mailman/listinfo/cores
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>