Hi, In some commercial VLSI EDA tools, the native symbol attributes (which comes from symbol library) are really just a place holder for viewing (location to update attributes from the external DB library). Not all attributes are used by the schematic, in reality, most attributes are used by other backend tools, such as simulation, path-analysis, layout, LVS, etc.
The native symbol does have a "base" attribute value which indicate its base cell (parts or component) family, and an index(key) attribute whose value is instance specifically assigned to select the set of attributes, and its corresponding parameterized schematics from its cell family attribute DB. This will make sure you wont select the wrong parts nor the wrong set of atributes values from the DB. In fact, this scheme is normally called the "parameterized cell" design, which makes billion transistor VLSI design possible. -----Original Message----- From: Levente <[EMAIL PROTECTED]> To: [EMAIL PROTECTED] Sent: Wed, 19 Dec 2007 12:33 am Subject: Re: gEDA-user: Parts DB API Steve Meier <[EMAIL PROTECTED]> wrote: > On Tue, 2007-12-18 at 23:22 +0000, Levente wrote: >> [EMAIL PROTECTED] wrote: >> >> Hi Peter, >> >> > >> >> The symbol files should be as light as possible, and we should make them >> heavy by adding information coming from the database. >> > > > So can we make a list of what should come from the light symbol and what > should be injected by the database? Symbol file should only contain graphical objects, and a pin identifiers, which has nothing to do with pinnumbers. Maybe a refdes prefix could included in the symbol file, like "refdes=R?". Footprint, value, description, documentation, model attributes, and pin assignment information must come from the datebase. Moreover, gsch2pcb could be taught to use information coming from the database, such as technology. For example the same component can have different footprints for reflow, wave soldering, etc. So maybe we should make some rules in footprint name format. Such as, for example SOT23_R.fp meaning SOT23 package for reflow technology. I have been using successfully the pinseq attribute as pin identifier, and made a small algorithm to add pinnumbers according to pin assignment information coming from the database. -- Levente http://web.interware.hu/lekovacs _______________________________________________ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user ________________________________________________________________________ More new features than ever. Check out the new AIM(R) Mail ! - http://webmail.aim.com _______________________________________________ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user