3 Replies Latest reply on Oct 7, 2008 1:16 PM by john_ferguson

    How to calculate total area for a layer


      I need to get DRC error when the total area of polygons for a layer is greater than x micron square. Any idea?

        • 1. Re: How to calculate total area for a layer


          Hi, I would try the command:



          AREA_TOTAL {DFM ANALYZE layer [AREA(layer) > Xlimit RDB ONLY "Result.rdb" INSIDE OF EXTENT



          • 2. Re: How to calculate total area for a layer

            I didn't know about the DFM ANALYZE method for doing this. I'm just now beginning to learn more about DFM and so was glad to see that post.  I ran some tests based on that and it works well. Here's what the SVRF looked like once I had it running:


            layer M2 1

            'layer_area_gt' {@ Total area of M2 is greater than 500 sq. microns

               DFM ANALYZE M2 [AREA(M2)] > 500 RDB ONLY "M2area.rdb"



            In case you don't have the DFM related license yet, you should be able to get similar results by using an expression in the DENSITY operation within nmDRC. There's a TechNote on SupportNet describing that method in case you're interested. Here's a link to it: TechNote MG244238

            • 3. Re: How to calculate total area for a layer

              Another method that doesn't require DFM ANALYZE is to simply use DENSITY:

              check{@error if area of layer A > x
              DENSITY A < x



              The default for density is to look at the entire extent of the chip.  By using the simple equation approach of AREA(A), you check only the area and not an actual density ratio.  You can get an RDB statement with the DENSITY operation if you want to know the exact value measured.