kicad-developers team mailing list archive

[Andy Peters <devel@xxxxxxxxx>]

On Mar 8, 2018, at 9:21 AM, Ouabache Designworks <z3qmtr45@xxxxxxxxx> wrote:
> 
> Why don't we run PCB layout on the schematic file and let it call the netlister program every time it runs. This is a simpler process flow with fewer cases where you make the user jump through hoops to get something done.

This makes a ton of sense. When working on a layout, it must match the schematic. 

(In the past, we had a rule. When a layout is complete, generate a new netlist from the schematic and import it into the layout. If layout reports no changes are necessary, the two are in sync and all is well.)

The netlist is just ephemeral, anyway; once it is imported into the layout it’s no longer necessary. The netlist is a vestige of the days when PCB CAD packages were a collection of disparate programs.

But … 

This action should be one way, that is, changes in the schematic should not force an automatic update of the layout. Consider: you made some updates to the schematic, and you’d like your colleagues to review it before you commit to it. They look at it, make suggestions, which might include not making the changes. If the layout automagically updated from your unreviewed changes, then you’d have to undo those changes in the layout.

This means that when you open the layout, it can notice that the schematic has changed and ask the user if it should be updated to sync with those changes. Because the answer might well be no, I am not ready to do that yet. Maybe you just want to look at the layout as it is, for whatever reason.

-a