layout connectivity extraction

Hi,
I'm trying to extract connectivity from a layout view, so that the user
can input a schematic or net name and my skill program will return a
list of shapes associated with the given net name.
It's not guaranteed that VXL will be used, so I initially wrote some
routines to extract net connectivity from the layout by looking for
text labels and what shapes they overlap, and what shapes connect to
that shape, etc. Is there a way to get this net name to shape id(s)
information in an easy way? I know the data exists because things like
any LVS routine needs that info, but I don't know how to access those
databases.

Thanks,
Brian

 

[Edward Kalenda]

On 7 Jun 2006 16:27:04 -0700, brian.gaide@gmail.com wrote:

Hi,
I'm trying to extract connectivity from a layout view, so that the user
can input a schematic or net name and my skill program will return a
list of shapes associated with the given net name.
It's not guaranteed that VXL will be used, so I initially wrote some
routines to extract net connectivity from the layout by looking for
text labels and what shapes they overlap, and what shapes connect to
that shape, etc. Is there a way to get this net name to shape id(s)
information in an easy way? I know the data exists because things like
any LVS routine needs that info, but I don't know how to access those
databases.

Thanks,
Brian

LVS uses the extracted view, which is very similar to a schematic.
Similar enough that an extracted view can be used anywhere a schematic
view can be used. The two real differences are that the extracted view
does not have wires showing the interconnect and there are usually
shapes from the layout present with net information.

After LVS is run, you can use the Diva cross probing UI to highlight a
schematic net or device and the matching net or device in the extracted
view. Sadly, it does not draw the highlight on the layout view as well.

You can also use normal probing in the extracted view to highlight a net
if you know the extracted view name. Assuming you use pins and labels
that match the schematic names, and the divaEXT.rul file was written
properly, the extracted view will have them.

 

[Roger Light]

Hi Brian,

I'm trying to extract connectivity from a layout view, so that the
user can input a schematic or net name and my skill program will
return a list of shapes associated with the given net name.

Not exactly what you asked for, but it might be interesting anyway:

http://groups.google.com/group/comp.cad.cadence/browse_thread/thread/fd09daa8a6252aac/27ffdb192183a9b7

Cheers,

Roger