Symbol editor: "This position is already occupied in unit 4"

A slightly long story: sorry.

I have an open source project that I am trying to modify. There is a large FPGA that is drawn as units A…F
Some pins in unit F are off grid. When I move the pin onto a gridline, I get a popup that says:
Confirmation (title of window) with text of "“This position already occupied in unit 4”

What does this mean?

  1. The “unit 4” notation is odd as the units are letters: A, B, C
    2.Is there some relationship between Units? The pin name and number are unique.
  2. It implies a physical collision of pins within the symbol, which makes no sense. I moved the entire symbol within the editor and that doesn’t help.

A search of this forum for “position is already occupied” did not return any results, so I’m thinking this is obscure.


Unit 4 sound like unit D.

What’s the fpga’s exact name?

It is a custom symbol

Since it is an open source project just throw the exported ‘symbol.lib’ file in here. We can take it from there.

Otherwise there is hardly any way to guess. I for one never came across such error message.

There are a few inconsistencies in the way multi-unit parts are referenced. One of them is some number them and some letter them. I’ve reported bugs on the ones I’ve come across and I suggest you do the same.

It is not a bug at all.

The exact message actually is --> “This position is already occupied by another pin, in unit 4.”

In the symbol editor under ‘Edit | Library Symbol Properties’ check ‘All units are not interchangeable’ which in your case they are quite likely not. If they are, then you simply move that pin to a different location.


I’d forgotten about this option.

Thank you!

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