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Net Connectivity result saved, does not include pin labels!

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DefconNowhere

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Hi all,

In Cadence Virtuoso Layout-L tool, I am trying to extract my chip power grid from the top layout and simulate it. I open the top layout and use Connectivity->Nets->Mark to trace connectivity and highlight Supply and Ground nets in the top layout. I ensure vias are included for saving as well as limit connectivity tracing down to metal 5 only. Once highlight is complete, I use Connectivity->Nets->Save All MarkNets to save all highlighted nets in a new layout. That is basically my power grid in the new layout.

I open this new layout, all is fine except I see pin labels are missing. It looks like they are removed somehow as a result of saving nets operation or just not highlighted in the first place.

Is there a way to include pin labels in the Saved Net Connectivity results?

Tnx!

DefconNowhere
 

I filed a ticket with Cadence and they confirmed this is not possible, it is either a bug or not implemented, bottom like does not work as intended. Shame on lousy tools they make.
 

As a simple work around, select all pin labels, then copy and paste them over your power grid layout.
 

Why not doing parasitic extraction of only these nets (power nets) form the original design, rather than creating a new one?
 

As a simple work around, select all pin labels, then copy and paste them over your power grid layout.

This is not always readily possible specially when you have a lot of pins and labels. Have tried it already.

- - - Updated - - -

Why not doing parasitic extraction of only these nets (power nets) form the original design, rather than creating a new one?
Because that will generate an extracted view which is not really a layout view. It is an extracted view.
 

This is not always readily possible specially when you have a lot of pins and labels. Have tried it already.

- - - Updated - - -


Because that will generate an extracted view which is not really a layout view. It is an extracted view.

How are you going to use layout view for simulation?

Usually, power nets are extracted, and post-layout netlist (DSPF / SPF file) is used for simulation by tools like Voltus or Totem.
Extracted view is just an internal database representation in Cadence system for post-layout netlist.
 

As a simple work around, select all pin labels, then copy and paste them over your power grid layout.
This is not always readily possible specially when you have a lot of pins and labels. Have tried it already.

I think the number of pins and labels doesn't matter: you can select all of them at the same time. By choosing the same scale, it's enough to align a single point (pin or label center) of this selection with your power grid layout.
 

Extraction is a way to go but as I explained earlier, I only want to have the grid up to M5. If I try to extract a power net, how can I tell the tool to extract the net up to a certain metal level and stop further down? Maybe it is possible but I didn't find it in either QRC or Calibre.
 

In the extracted view, the connectivity becomes a property
of the net polygons (which probably are found on a "net"
purpose layer - e.g. Met1/net, rather than the source
Met1/layout). If this happens then the Met1/layout and
the Met1/pin will neither one be transferred to the
extracted view.

Check the properties of some net you had pin-tagged and
see if the connectivity has been assigned.
 

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