Via P(y)Cells

[martinjankoehler]

NOTE: depends on PRs #671 and #670, please review/merge those first

• PyCell ViaStack supports Cont/Activ/GatPoly
• Native KLayout PCell added separately, which is necessary for the new KLayout 0.30.4 Path-Via-Feature (place via using shortcut 'O')

[mole99]

This is a great enhancement to the KLayout setup. I just saw Matthias demonstrate it in the "MICROELECTRONICS 2025: From Technology to Application" webinar.

[martinjankoehler]

OK, added some changes:

• Now enclosure rules *.c vs *.c1 are honored
• Bigger array spacing rules *.b vs *.b1 are honored

[KrzysztofHerman]

@martinjankoehler thank you for these contributions, I am reviewing it.
The issue I have after merging 670,671 and 703 is that I get these errors after hitting 'O' key:

ERROR: /home/herman/github/KrzysztofHerman/IHP-Open-PDK/ihp-sg13g2/libs.tech/klayout/python/sg13g2_native_pcell_lib/sg13_klayout_tech_info.py:76: AttributeError: 'ViaInfo' object has no attribute 'klayout_via_type' in PCellDeclaration.via_types
  /home/herman/github/KrzysztofHerman/IHP-Open-PDK/ihp-sg13g2/libs.tech/klayout/python/sg13g2_native_pcell_lib/sg13_klayout_tech_info.py:76
  /usr/lib/python3.12/functools.py:995
  /home/herman/github/KrzysztofHerman/IHP-Open-PDK/ihp-sg13g2/libs.tech/klayout/python/sg13g2_native_pcell_lib/via_pcell.py:67

[martinjankoehler]

@KrzysztofHerman

Thanks for the report, I've added 2 commits that should fix this issue.

[KrzysztofHerman]

@martinjankoehler thank you it works, I will continue the review. It looks very good.
Until now I have one question: What was the motivation to introduce a separate native library ?

[martinjankoehler]

@KrzysztofHerman this is required for KLayout's O-keystroke Feature to work.
I have therefore separated:

1. in regular IHP library
   • via_stack: PyCell based, no KLayout dependency to be compatible with proprietary flow
   • TechInfo: encapsulating DRC rules reusable for both via_stack and via_pcell below
2. KLayout-native library, currently containing via_pcell
   • after this library is registered/loaded at startup, then KLayout knows what to do if user presses O

[KrzysztofHerman]

@martinjankoehler a time ago we have introduced a "preprocessor like" constructs to
distinguish between different tools, which actually make function calls ie.

#ifdef KLAYOUT
        klayout specific code
#else

#endif

maybe it is a helpful information.

[martinjankoehler]

@martinjankoehler a time ago we have introduced a "preprocessor like" constructs to distinguish between different tools, which actually make function calls ie.

#ifdef KLAYOUT
        klayout specific code
#else

#endif

maybe it is a helpful information.

Thanks for the info, I already saw it. In this case I found it cleaner to keep it separate for multiple reasons:

• cleaner code with separation of concerns
• easier to debug in isolation without preprocessing
• the native library can serve as a template for other Open PDKs to implement the O-Feature

IMO in the IHP context, these native pcell library should be kept to a minimum (to honor the PyCell4KLayout strategy), but is useful exactly in those rare cases of KLayout-specific features (like O), where a real native KLayout PCell is mandatory.