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Extract VXL Correspondence and Connectivity from LVS

MG202412171211 5 months ago

I have some product schematics and layouts that began life unlinked - developed by two separate teams in separate libraries. Don't ask why, it's just how they did it.

I would now like to merge these into a single library (as it should be) and correct the VXL connectivity. But I don't want to bind each instance by hand! The cells do correspond well, and all listed schematic devices are properly represented in the layout. It's just that they were not generated through VXL so the correspondence never existed.

When I LVS, the tool can find device correspondence and connectivity and tell me that the schematic's MN23 is layout instance I94, for example. I would like to use the LVS result to update the VXL compliance, and I am told there is or was a tool to do this, but I can't find any references or documentation.

Can you point me to the documentation for this tool, or any relevant Skill that may also do this job? The LVS database I use for this can come from either Assura or Calibre, but Calibre is preferred.

Alex Soyer 5 months ago

Hello,

You can use the Update Binding capability as described in this link:

https://support.cadence.com/apex/techpubDocViewerPage?xmlName=vxlhelp.xml&title=Virtuoso%20Layout%20Suite%20XL:%20Connectivity%20Driven%20Editing%20User%20Guide%20--%20Update%20Binding%20Form%20-%20Update%20Binding%20Form&hash=pgfId-1247390&c_version=IC23.1&path=vxlhelp/vxlhelpIC23.1/xlForms_re_Update_Binding_Form.html#pgfId-1247390

You need to get the ixf (instance cross reference file) and the extracted layout netlist (.net for Pegasus or .spi/sp for Calibre).

If you advise you to use a recent Virtuoso version to get advantage of all the recent improvements.

Thanks,

Alex
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MG202412171211 5 months ago in reply to Alex Soyer

Alex,

Thanks a lot for the link and advice! I spent the day on it with one of our layout managers, and we made progress but could not get to the goal.

Our Calibre LVS does generate an .IXF file and .SPI for the extracted layout. But when we input these to the binding tool we get an error that I think is inaccurate:

*WARNING* (LX-2171): No bindings were added to the binding file, possibly because the 'Input Scale' value
set on the Update Binding form is different from the value used for the PVS LVS run.

Our IXF and SPI have no references to scale (should they?). We have set the Input Scale on binding form using the command below:

gec()~>DBUPerUU

It all looks consistent, but the binding run throws errors for each device, then finally the error above.

Could I ask what the header of IXF is supposed to look like? Here is mine

# SVDB: Instance Cross Reference (ixf) (File format 1)
# SVDB: Layout Primary logics
# SVDB: Rules -0 <deleted for confidentiality>.tvf_ Mon Mar 10 17:09:01 2025
# SVDB: GDSII -0 (none) (none)
# SVDB: SNL -0 (none) (none)
# SVDB:
# SVDB:
# SVDB:
# SVDB:
# SVDB: End of header.
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