5 Replies Latest reply on Sep 28, 2013 5:14 AM by tommark

# how to pick large space

Sometimes we need to pick the special structure with large space. But the EXTERNAL command always include pairs of edges between which other polygons exist. And EXTERNAL has no option to filter these edges.

Herewith below is my suggestion for pick large space edge, please help me double check and i hope you can share a better way.

a = external [layer] >= a <=b opposite

b = external [layer] < a opposite

c = not coincident edge a b

• ###### 1. Re: how to pick large space

I think DFM SPACE is optimized for the situations you mentioned. It should be much better than EXTERNAL for these cases. The SVRF manual describes DFM SPACE in detail.

• ###### 2. Re: how to pick large space

Good idea. Thank you for your advice.

But I don't know why script one would abort with "Segmantation fault" and script two would be OK.

Script one:

A = DFM SPACE [X] >=a <=b BY EXT

B = INTERNAL REGION EXTENTS A >=c <=d OPPOSITE

Script two:

A = DFM SPACE [X] >=a <=b BY EXT

W = DFM SPACE [A] >=c <=d BY INT

B = INTERNAL REGION EXTENTS W >=c <=d OPPOSITE

• ###### 3. Re: how to pick large space

Do you get the same results when the keywords "REGION EXTENTS" are placed at the end of the line instead of in the middle? Like this:

B = INTERNAL A >=c <=d OPPOSITE REGION EXTENTS

Instead of this:

B = INTERNAL REGION EXTENTS A >=c <=d OPPOSITE

• ###### 4. Re: how to pick large space

Yes, I have tried putting "REGION EXTENTS" at the end of the command line and got the same result.

• ###### 5. Re: how to pick large space

Now I know the best way to solve this problem is  "exclude shielded" argument.

like this:     external X >a <b opposite exclude shielded