Re: gEDA-user: inverted pins?

[sdb@xxxxxxxxxx (Stuart Brorson)]

> Ok, what's the standard for inverted pins in symbols?  How do I (or do
> I) put the bar over the text? 

Getting bars over the pinnames is not easy in most EDA programs.
Therefore, I have seen the following work-arounds used in real life: 

*  Signals asserted low are sometimes called e.g. RESET_N, with the
_N signifying that it is asserted low.

*  PCI bus signals asserted low are suffixed with #.  Example:  RESET#

*  High speed designers who work with diff signals will call their
signals things like DATA_P & DATA_N (plus and minus), or DATA_H and
DATA_L (high and low).

I'd say that the bar notation is becoming obsolete due to the
influence of ASCII printing characters and the predominance of EDA
programs for schematics instead of hand-drawn ones.  Therefore,
perhaps we should just follow the trend and not put bars over
asserted-low logic signal names?

Just MHO.

> I've written a program to extract/insert attributes into .SYM files
> (gattrib seems to want whole schematics, not symbols), using open
> office's spreadsheet to sort/edit/fill.  The script knows where to put
> "new" attributes (you can add a column and it inserts them, plus it
> knows about the standard attributes), assuming I've guessed OK about
> where to put them.

Kewl program!  When will you release it?

You are correct that gattrib expects to read schematic files, not
symbols.  What did it do when you read in a .sym file?  I hope it
didn't barf ...

Stuart