Stefan Salewski wrote: > Am Mittwoch, den 05.11.2008, 10:06 -0800 schrieb Joerg: > >> Just as a suggestion, the way Eagle does this is quite ideal: >> >> you click >> an invoke tab and the hidden power pins show up on the -A slot. But only >> for the device you click after invoke, not all of them. >> > > Sorry, have not followed all of your posts. > > One question to the professional: > Are hidden power pins really useful today?
Yes, but only really on systems where almost everything runs on 3.3V or 5V. It's also very useful for opamps in audio gear or massive level-detector circuits. I use hidden pins probably on 20-30% of my circuits but typically only in the bus interface portion. > I think they are invented in the 1970 when logic devices all work with > +5V and ground. Today so much logic voltages are common, i.e 1.2 and 1.8 > and 2.5 and 3.3 and 5V. I have all these voltages in my DSO schematics, > and much more for other devices. So I think hidden power pins/nets (some > devices shipped with gEDA have it) can generate more problem than > benefit, so split symbols with separate, visible power pins may the > better way? > If I had a choice I'd always prefer non-hidden power pins. Eagle has taken this compromise away in a nice fashion. Most devices have hidden power pins and if you don't want that for certain areas of you schematic you just click "invoke". All nicely from the GUI, you never need to close and go to the command line (which is _very_ practical). But their rendering leaves something to be desired. Some ugly text smears across the device when you scoot the power pins to U7A, says U7P or something. That's nice if you decide to place the power pins all in a corner but not when overlaying it on top of the first slot of a device. -- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM. _______________________________________________ geda-user mailing list [email protected] http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
