kicad-developers team mailing list archive

[jean-pierre charras <jean-pierre.charras@...>]

Dick H. a écrit :
> Thank you. With your comments and some study, I now understand the
> issue fully. The plan I had wanted to see implemented is outlined in
> the todo.txt file within the project. Phase 1) I now realize is
> basically the functionality that we have now, but when using a
> netcode=0 TRACK (not EDGE_ZONE) to delimit the zone. TRACKs are saved
> into the *.brd file, whereas EDGE_ZONEs are not. So I see no point now
> to implementing phase 1). We should work toward phase 2) as time
> permits. 
I'll try to work on this topic.
A first enhancement (out of this topic, but desirable) could be consider 
zones in ratsnest calculation.
Of course saving edges zone is easy but creates a lot of problems which 
must be solved
1 - trivial, but easy: edges must be editable (only a lot of work and 
some code)
2 - must we save zone parameters (net name, zone clearance, grid ... ) 
with the zone or use the current zone parameters (which can differ from 
initial parameters)
3 - How to handle safely the net name of the zone:
An usual case is a ground zone. But many components use GND as 
ground name, and many others useVDD.
So, in a schematic including components using GND and VCC, the same 
net can have the net name GND or VDD.
Therefore, if a zone initially created with GND as net name must be 
refilled,
and at this time (after some schematic changes) the same net is now 
called VDD, what we must do ?
4 - And at last but not at least :
Often, on the same layer a board can have more than one zone. This 
creates difficulties:
What is a edge zone ? Suppose you create 2 zones (for instance a Digital 
GND, and an Analog GND) not overlapped.
Later, you move a frontier and now a zone overlaps the other zone.
What refilling must do: fill the new area and overlaps the other zone, 
or stops at the frontier of this other zone.
Same problem when creating a new zone overlapping an old one, relative 
to the same net : Is the frontier of the first zone is a frontier for 
the new one ?
And what we do when refilling zones if a zone was previously deleted and 
its edges are kept.

We must have some thoughts about this problems and also about what we want.

--

Jean-Pierre CHARRAS

Maître de conférences
Directeur d'études 2ieme année.
Génie Electrique et Informatique Industrielle 2
Institut Universitaire de Technologie 1 de Grenoble
BP 67, 38402 St Martin d'Heres Cedex

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