Mail Archives: geda-user/2015/07/16/19:23:55
On Jul 16, 2015, at 3:15 PM, John Doty <jpd AT noqsi DOT com> wrote:
>
> On Jul 16, 2015, at 2:45 PM, DJ Delorie <dj AT delorie DOT com> wrote:
>
>>
>>> What happens if the same segment in different instances of a
>>> subcircuit has different properties, for example?
>>
>> Does our heirarchy system even have a way of parameterizing
>> subcircuits? I mean, if you had a subcircuit for a generic low-pass
>> filter, could you specify the cutoff in the parent somehow?
>>
>
> Nope. I sometimes have to make multiple copies of a subcircuit schematic: same topology but different components. Having more control over hierarchy expansion in gnetlist would be good.
Thinking about this some more, I think I would implement this by generating the customized schematics explicitly by forward annotation rather than by a implicit process in gnetlist. Automate my manual process. The main reason is that for documentation, I want the annotated schematics anyway. Hierarchical schematics are hard enough to deal with on the bench. I think hierarchical, parameterized schematics would cause a revolt ;-) And once you have the annotated schematics, you might as well use them as input to netlist generation. Easier and less error prone than making the netlist and docs from different files.
This is another reason to promote 1.9.whatever to 1.10.0 and get it out. Forward annotation of .sch files is not fundamentally difficult. For simple cases, sed suffices. However, figuring out what to do in a hierarchy has always been difficult because hierarchy expansion depends on both the symbol and source search paths. These have historically been controlled by the Scheme configuration files. It has been tricky to determine exactly which .sym and .sch files are involved (even from Scheme scripts). But in 1.9, we have .ini style configuration files that are much more friendly to a variety of scripting languages. Thank you, Peter Brett.
John Doty Noqsi Aerospace, Ltd.
http://www.noqsi.com/
jpd AT noqsi DOT com
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