2 Replies Latest reply on Jun 6, 2016 9:13 AM by tiamon

    How to ignore the Power Net Extraction in an LVS BOX cell

    tiamon

      Hi ,

           I've a database with some IPs and clock tree network inside. The Power Supply for this one is distributed from TOP to each VDD/VSS Pin of std cells (used for clock tree network) and VDD/VSS Pin of IPs.

           Now, i want to extract parasitic data relating to clock tree network only (it will include : clock tree network cells + clock tree signal routing  + power distribution routing ), I've used LVS BOX to box all IPs. However, the parasitic data of Power Suppy Distribution (VDD/VSS) still contains the data of IP Power Routing.

           How can i get the parasitic data of Power Supply for Clock tree network only and ignore all the Power data belonging to IPs ?

       

      Thanks,

        • 1. Re: How to ignore the Power Net Extraction in an LVS BOX cell
          samantha_lizak

          Hi Tri-

           

          To get just the power and clock tree, you probably want selected net extraction.  You may also want to mark the IP as "ideal" in your xcell list, if it isn't already.  (The xRC manual has a figure, "Device Extraction With and Without Parasitics", that shows the effect of using ideal xcells.)

           

          The method to do this depends on whether you are running from the command line or GUI, possibly what version you are using (though the changeover is pretty long ago now), and what type of parasitics you need overall.  The tool manuals (xrc_user, calbr_inter_user, xact_user), which are available in your docs directory, give the techniques but might be using different terms than you have searched on.

           

          Good luck-

           

          Sam.

          • 2. Re: How to ignore the Power Net Extraction in an LVS BOX cell
            tiamon

            Thank you so much, Sam

            I'll try it

             

            Regards,

            Tri  

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