Mail Archives: geda-help/2020/12/09/03:34:33
Roland Lutz:
...
> Components with a netname= attribute are considered power symbols, i.e.,
> their only pin is connected to a named net. Typical examples for this
> would be "netname=GND" or "netname=3.3V". The older way of doing this is
> using a "net=3.3V:1" attribute, but this has the disadvantage that you
> can't use that attribute as the visible text without having an ugly ":1"
> suffix. With the netname= attribute, you can draw a single "power rail"
> symbol and change the attribute value to whichever power rail you want it
> to connect to. (In practice, you'll probably want to have a separate,
> visually different symbol for GND.)
...
All thoose things with net/netname/portname is simply confusing,
why not only use one attribute name for all this ?
Also confusing if the talk about "power symbols". It is all about
some named net, which is useful for power nets _among other forms of
nets_.
Why not get rid of the "netname attribute attached to a net", since
you can simply attach a net symbol instead to get the same thing ?
Regarding the ugly ":1", cannot a missing :<number> just default to :1
(this has been up to discussion before) ?
Regarding portname, I have not heard about it before but I can find it
in http://wiki.geda-project.org/geda:symbols,
<<
I/O port symbols
Subschematics are hooked up to the schematic from which they are
instantiated via port symbols. Instead of a refdes= attribute,
port symbols have a portname= attribute; for each pin on the
subschematic symbol, there should be exactly one I/O port in
the subschematic whose portname= attribute matches the pinlabel=
attribute of the pin. Port symbols mustn't have a pinnumber=
attribute on their own pin.
>>
I don't know why the text insists on "exactly one", since nets has
the tendency to be useful when there is "more than one".
From what I can see, the portname is just a net attribute without
the ugly :1, so what does the portname way of doing it solve versus
the "old" net way ?
Regards,
/Karl Hammar
- Raw text -