Re: ERC

[Steven Rubin]

> I need your help to explain how to correct ERC errors
> from PADs. Is the Pad distributed with incomplete
> design means the user need to check ERC or etc. Below
> are some of the error appeared after ERC. All the
> errors are came from PADs.
>
> ERC error 1 of 896: P-Well contact not connected to ground

I checked one of the cells in the "pads4u" library.  Some of the exports in 
these cells have the "bidirectional" characteristic when they probably 
should be labeled "ground" or "power".  The problem comes from the fact 
that there are two supply rails being used there: clean and dirty.  The 
secondary power/ground rails are often not given the "power" and "ground" 
characteristics so that they don't accidentally get merged with the clean 
supplies.  This is one of the areas where Electric is not consistent in its 
analyses.

   -Steven Rubin