Mail Archives: geda-user/2012/11/14/10:55:32
On Nov 14 2012, Nathan Stewart wrote:
[snip]
>I was unclear about slotting of broken out symbols, or where the 'slots'
>are not identical (such as where I was using slots to represent both sides
>of the optoisolator).
In the gEDA world, this isn't slotting per-se, but having multiple symbols
to connect different parts of a complex chip is common practice.
What I would do is to ignore slots, and make two separate symbols (if you
want to separate transmit and receive). Each will be instantiated with the
same refdes (e.g. OPTO1 or something like that), and the netlist will "just
work". Each symbol can just use the pins it requires.
This probably won't play well with the renumber tools out there, and I'm
not sure it is a good idea to try and trick them by invoking slotting.
Myself, I'd make an opto-pair one symbol (containing transmit AND receive),
and would only use slotting if I had multiple opto isolators within the
same chip.
Finally.. if you do use multiple symbols anywher, there is (or was?) a
problem you have to work around, in that when picking up the symbols to
retrieve attributes from (e.g. for forwarding to PCB layout), it was not
clear which of the two symbols would be scanned for attributes.
To get around this, add the "footprint=..." and any other attributes you
need to be "machine" readable to both halves of the symbol.
(If this issue hase has been resolved already, someone please let me know).
Best wishes,
Peter Clifton
Best wishes,
Peter Clifton
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