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How to create custom footprints:

Question asked by JERRY_MARKETOS on Nov 22, 2004
How to create custom footprints:

Genesys provides many footprints for use in Layout, but it's common to have the desire to make
a footprint of one's own.  Genesys provides this capability, as well.

The process of creating a footprint involves constructing the footprint (similar to drawing a mini-layout)
and saving the footprint in a library.


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If you are making your own footprint, I strongly advise that you do not save your footprint into any of
the existing footprint libraries shipped with Genesys.  Instead, create your own new footprint library.

Why ?  Because this will organize your custom footprints neatly into a folder where they are segregated
and you can access them easily (such as for copying to co-workers or copying to future new installations of Genesys)

How ?  It's easy.  See this seperate post:   http://forum.eagleware.com/viewtopic.php?p=3807
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To create the footprint itself isn't difficult, either.  There exists one stumbling block to avoid:

(This is also covered within Genesys HELP by searching for "footprint", then see "creating and saving...")

Within Genesys, main menu TOOLS, FOOTPRINT EDITOR, then "New Footprint".
(you can also load an existing footprint and modify it if you wish)

This will bring up something that looks like a layout window.  Set the grid and box size appropriately.
Exactly where the footprint is drawn within the box... isn't critical.  Set the grid size appropriately to
help with your own dimensional resolution.  Box size isn't critical, either.

Draw the footprint.  This can include metal, silkscreen, soldermask (various layers) etc.

Here's the stumbling block to avoid:  When drawing the footprint metal on the "metal" layer, don't obtain
the metal by drawing metal rectangles.  (Don't use what is at the time of this writing the red "draw rectangle" icon.)
Instead, you must obtain the metal sections by using the "pad" icon, which is the round (stopsign) looking icon,
generally located next to the yellow ruler icon.  Once the pad is placed, you can change its size & shape through
its "properties" box, including square or rectangular (not just round).

Next, place ports on top of the pads.  The "port" is gotten from the small box icon with the black "X" in it.
(mouse over this icon, it will say "Draw EM port (layout editor) or Footprint port (footprint editor)

[If the footprint was drawn using metal rectangles instead of pads, those metal areas won't be seen by the
EM simulator- they'll usually be treated as open circuits.]

As a side note, you don't need to have a port for every pad in the footprint.  Rather, the number of ports generally
should match the number of nodes in the schematic symbol(s) that will be used for this footprint.  For instance, it's
quite common to draw something like a 6 pin DIP footprint (6 pads) and use only 2 or 3 ports in it.

The ports provide the electrical connection link between the schematic and the footprint pads.
As you place ports in the footprint, you should note that their numbers start with A1 and increment A2, A3 etc.
If you're just seeing regular numbers 1,2,3  then you should stop;  you're probably drawing in a regular layout
and not in the footprint editor.

When you're done drawing your new footprint, remember to save it into your footprint library
(main menu Tools, Footprint Editor, Save Footprint)

To use a new footprint, go to the layout and doubleclick the desired component, then click its "change footprint" button.  

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