> > Em Sex 03 Mar 2006 21:32, John Luciani escreveu: > > The gschem logic symbols seem to have embedded Vcc and GND connections > > (at least the ones that I was looking at). Since I am working on a > > board that has 3.3V and 5V logic this is a problem. > > > > I created a script that takes a logic symbol with embedded Vcc and GND > > nets and creates (1) a new symbol with the power nets removed and (2) > > a new symbol with two power pins. My plan is to place power symbols > > (and decoupling caps) for each IC in a separate section of my > > schematic. > > > > Since many symbols contain the same pinout for power pins the power > > pin symbol is a symlink to a generic symbol. The new symbol without > > power pins have a _np suffix. The symbol containing the power pins has > > a _pwr suffix. > > > I allways used that way. I redrawed all my symbols to fit that standard. > Unfortunatelly, there are a lot of people that dislikes that way. > IMHO all the pins used in a component must be showed on the schematic, no > matter what the pin is. I have a lot of boxes with power pins, and its a good > way to place decoupling caps. > When you mix analogic components with digital, its common to have, for > example, two 5V, one for the digitals and another for the analogic. If you > use the embedded pins, they will all use only one power supply. And when > routing the board, its better to know exactly where all the connections go > taking a look at the schematic.
FWIW, I wrote a blurb about this question for the wiki a couple of weeks ago. Here it is: http://geda.seul.org/dokuwiki/doku.php?id=geda:faq-gschem#what_should_i_do_about_power_pins_on_my_symbolsmake_them_visible_explicit_or_invisible_implicit Stuart
