Re: gEDA-user: Split ground planes and zero ohm jumpers

[Russell Dill <russd@xxxxxxx>]

On Fri, Apr 8, 2011 at 9:39 AM, rickman <gnuarm.geda@xxxxxxxxx> wrote:
> On 4/7/2011 1:13 PM, Stephan Boettcher wrote:
>>
>> rickman<gnuarm.geda@xxxxxxxxx> Âwrites:
>>
>>> I have to say I am philosophically opposed to any feature that allows
>>> a design to pass DRC when the layout differs from the schematic.
>>
>> Just to get the terminology right:
>>
>> DRC has no business to care about the schematics at all. ÂThere shall be
>> a tool to check if the layout implements the schematics netlist, but
>> that is a different issue.
>>
>> PCB implements this distiction properly. ÂDRC checks consider coper
>> structures as layed out when evaluating the rules, without regard to the
>> netlist.
>>
>> The Rat's-nest (O-key) ignores DRC rules when checking connectivity.
>
> ÂOk, if you want to be pedantic the net list is not the schematic, but if
> the netlist differs from the schematic, then you have another problem.
>
> DRC is a part of my design process which includes a verification that the
> layout matches the net list. ÂIn fact, my number 1 "design rule" Âto be
> checked is that Âthey match. ÂWhat button I push to get the tool to do my
> required design rule checking is irrelevant. ÂIt is just a tool and does not
> define my process.
>
> So my point is that adding an attribute to any copper to tell the tool to
> ignore the connectivity violates my idea of design rule checking.
>

I'm not sure if it could be done simpler, but for a special copper
trace that connects two planes, you would do DRC twice, one time
ignoring between the trace and plane A, and another between the trace
and plane B. Or perhaps just run that portion of the DRC twice. Or
just make a special region where the connectivity between net A and
net B is ignored where they touch.


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