Stream out GDS and maintain its hierarchy as it appears in design database (library manager)

Deyan,

That's very odd. I'm not aware of anything that can split the top level cell like this. In general, the hierarchy should be preserved, with the exception that PCells usually end up with a separate STRUCT (cell) per variant, although they can also be flattened if the "Flatten Pcells" is checked (on Geometry::Transformation) or similarly the Flatten Vias (on the same settings page.

Can you share the stream out log file?

Andrew

Deyan,

That's very odd. I'm not aware of anything that can split the top level cell like this. In general, the hierarchy should be preserved, with the exception that PCells usually end up with a separate STRUCT (cell) per variant, although they can also be flattened if the "Flatten Pcells" is checked (on Geometry::Transformation) or similarly the Flatten Vias (on the same settings page.

Can you share the stream out log file?

Andrew

Hi Andrew,

Upon a second look today, it seems the hierarchical structure is indeed preserved and I was wrong. The automatic naming is what has confused us. Since there are different instances of cells (which share the same name) from multiple libraries, to avoid name collision the stream out tool adds a _0, _1, 0_13, _X... after the names of the colliding cells.

Is it possible to set the stream out exporter to append (or pre-pend) the library name of the colliding cells, instead of just an incremented number?

Here is an excerpt from the stream out log file:

WARNING (XSTRM-145): The structure name 'top' has been changed to 'top_0' by the translator. This could be because multiple cells with the same cell name exist in different libraries, the same cell name has been mapped to multiple cell names, or the cell name length is greater than the '32' that was specified using the '-respectGDSIINameLimit' or '-gdsCellNameLength' option.

Regards,
Deyan

Deyan,

I couldn't find anything that quite does this, but maybe the code snippets in this article could be adapted?

XStream Out: How to add or remove a Prefix or suffix to/from all Cells during Stream Out and Oasis translation; How to avoid rename of top cell and some specific cells during the streamOut or strmout

If not, I suggest you create a case on the customer support site.

Kind Regards,

Andrew

Good morning Andrew,

Thank you for these tips. It seems what I want to achieve is a bit more involved than what I initially thought.

This inspired an idea to create an export tool which appends library names to cells with expressions in an unique way, such that when exporting a gds one would still be able to edit reasonably well with an open-source layout tool e.g. KLayout. I currently get lost with all auto-generated cell names and what comes from where.

Then one can export back from KLayout a gds which would be imported back to Virtuoso and parsed with a script which would generate libraries and cells based on the unique cell naming contained in the gds.

Regards,
Deyan