On Dec 19, 2007, at 2:18 AM, Paul Tan wrote: > 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.
Yes! Yes! > > 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 > [email protected] > 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 > [email protected] > http://www.seul.org/cgi-bin/mailman/listinfo/geda-user John Doty Noqsi Aerospace, Ltd. http://www.noqsi.com/ [EMAIL PROTECTED] _______________________________________________ geda-user mailing list [email protected] http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
