Hi!

I'm using
    setNanoRouteMode -droutePostRouteSwapVia multiCut
    routeDesign -viaOpt
in Encounter (9.1) to automatically convert single vias to multi-cut vias
after the initial routing.
The result is that I end up with via arrays of 50x50 vias since in parts
of the design lots of space is available, especially on higher layers.

Is there a way to limit size of the generated arrays to - say - 3x3 vias?

My vias are generated from a GENERATE DEFAULT rule. I guess removing the
generate rule and only explicitely defining small arrays would work, but
I would like to avoid that work if possible.

Joerg

--- news://freenews.netfront.net/ - complaints: news@netfront.net ---

On Feb 3, 3:26=A0am, Joerg <jo...@sofort-mail.de> wrote:
> Hi!
>
> I'm using
> =A0 =A0 setNanoRouteMode -droutePostRouteSwapVia multiCut
> =A0 =A0 routeDesign -viaOpt
> in Encounter (9.1) to automatically convert single vias to multi-cut vias
> after the initial routing.
> The result is that I end up with via arrays of 50x50 vias since in parts
> of the design lots of space is available, especially on higher layers.
>
> Is there a way to limit size of the generated arrays to - say - 3x3 vias?
>
> My vias are generated from a GENERATE DEFAULT rule. I guess removing the
> generate rule and only explicitely defining small arrays would work, but
> I would like to avoid that work if possible.
>
> Joerg
>
> --- news://freenews.netfront.net/ - complaints: n...@netfront.net ---

Hi,

I don't have a testcase but from the LEF 5.7 documentation, it looks
like you can create fixed 3x3 vias as DEFAULT and use GENERATE for a
range of metal widths so that anything outside these widths will take
the default (3x3).
I might be wrong here but I think it looks like this:

-------------------------------------------------------------------------
#lefdefref.pdf pg 220

VIA myDefaultVia
   VIARULE DEFAULT ;

   CUTSIZE 0.1 0.1 ;
   LAYERS  M2 VIA23 M3 ;
   CUTSPACING 0.1 0.1 ;
   ENCLOSURE 0.05 0.01 0.01 0.05 ;

   ROWCOL 3 3 ;     # 3x3 default
END myDefaultVia

#lefdefref.pdf pg 222 , pg224

VIARULE myVia23 GENERATE
   LAYER M2 ;
      ENCLOSURE 0.05 0.01 ;
      WIDTH 0.1 to 2.0 ;              # valid rule only for M2 width
between 0.1 - 2.0 um
   LAYER M3 ;
      ENCLOSURE 0.05 0.01 ;
      WIDTH 0.1 to 2.0 ;              # valid rule only for M3 width
between 0.1 - 2.0 um
   LAYER VIA23
   RECT 0.1 0.1 ;
   SPACING 0.1 BY 0.1 ;
END myVia23
-------------------------------------------------------------------------

To be honest, I've never come upon anything like this since usually
wide metal layers (6um and above) I have are used for power/ground
rings/stripes and I usually use as much via as I can to switch between
the layers.

Best Regards,
I-FAB