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Re: gEDA-user: Getting symbols from ASIC libraries into gschem: one approach

Hi Jeff,

El lun, 11-06-2007 a las 21:55 -0700, Jeff Trull escribió:
> Hi all,
> I'm consulting for a small ASIC startup that is interested in gEDA.  They have 
> a handful of licenses for expensive commercial tools but were looking for a 
> low-overhead way to do some semi-custom work and asked me to investigate.  I 
> just went through the process of figuring out how to make symbols for the 
> third-party standard cell libraries they've licensed, and I thought I'd share 
> my experiences since I couldn't find this described on the net anywhere.
> Among the provided views of this library are ones for Cadence's Composer 
> product.  It turns out Cadence supplies a tool called "edifout", which will 
> produce an EDIF (text) version of any cell view.  You need to supply a 
> template file, which Cadence helpfully provides an example of 
> (tools/dfII/samples/xlUI/edifOut.il).  I wrote a Perl script that just runs 
> this once for every cell in the library, although some people recommend 
> building a huge schematic with every cell in it, and then running edifout 
> just once.  With my approach you do need to generate a new template file each 
> time, specifying a different cell (and you want the "symbol" view).
> Now you have EDIF for each cell's symbol view.  From here I tried to find some 
> kind of public-domain parser, but everything was a dead end.  Then I realized 
> that EDIF looked kind of like Lisp - i.e., an "s-expression".  It turns out 
> there's a CPAN module for parsing s-expressions called Data::SExpression, so 
> I could suck in the whole file and treat it as a data structure (lists of 
> lists).  I did have to do a few day's worth of coding on top of this to 
> generate the gschem symbols - the EDIF can be complex and the vendor 
> libraries are quirky.  

This could be a path other people may be interested in. If you are
willing to share the scripts, they may be incorporated into gaf utils
package. Of course, if there is no licensing/patent conflicts...



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