From: Shaun Feng (xsfeng_at_cs.ubc.ca)
Date: Fri Jan 09 2009 - 13:39:28 MST
a BDD to a concise logical expression?
There is no simple solution for large size of BDDs. it is the
boolean functions simplification (logic minimization) problem. If your
BDD has a big number of variables (and minterms), simple Karnaugh Maps
or Boolean Algegra cannot provide any good results. (and there is no
guarantee that there is a unique best "concise" result.)
But you can use many existing algorithms that can give you a
sub-optimal solution with reasonable runtime/memory usage.
So my answer is as I know, there is no such a function in CUDD or
VIS package. I remember I used Sis (A System for Sequential Circuit
Synthesis). There is a full_simplify command in synthesis steps. You
might can take a look of it. You can use the intermediate results of
synthesis, which could give you a "reasonable" answer.
Thanks,
Shaun.
On Thu, Jan 8, 2009 at 8:33 PM, Aly Farahat <anfaraha_at_mtu.edu> wrote:
> Thank you all for help.
> What about expressing it in a concise logical expression? Does such a function exist?
>
> ----- Original Message -----
> From: "Fabio Somenzi" <Fabio_at_colorado.edu>
> To: vis-users_at_lists.Colorado.EDU
> Sent: Tuesday, January 6, 2009 8:35:14 PM GMT -05:00 US/Canada Eastern
> Subject: Re: your mail
>
>>>>>> "SF" == Shaun Feng <xsfeng_at_cs.ubc.ca> writes:
>
> SF> Cudd_DumpDot can print a BDD to a graph in dot format (you can edit
> SF> the dot file very easily. I did that cause I want to change names for
> SF> nodes). Then, you can use dot2ps inside graphviz package to get
> SF> postscript graph.
>
> SF> http://vlsi.colorado.edu/~fabio/CUDD/cuddAllDet.html#Cudd_DumpDot
>
> Cudd_DumpDot is what I would also recommend. From within vis, you can
> call bdd_dump_dot, which is just a wrapper function. If you don't
> have an application that manipulates BDDs, you can try downloading
> DDcal from:
>
> ftp://vlsi.colorado.edu/pub/DDcal-0.7.tar.gz
>
> You need, CUDD, Perl-Tk, and graphviz to build it.
>
>
> Fabio
>
> --
> Ph.D. Student
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>
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>
>
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