skywater 130 tech file not working

[EldritchIHC]

Hello.
I am trying to use your tool to generate some inductors in virtuoso in a research technology. I have firstly installed the tool on my ubuntu vm where I have the complete tool suite for sky130 PDK. I am trying to generate a mos using this command: ./opc --technology skywater130 --export gds --cell basic/mosfet and i get this error : /home/ubuntu/openPCells/tech/skywater130/layermap.lua:5: attempt to call a nil value (global 'array') . I have commented all array and map commands and now I get this error: /home/ubuntu/openPCells/tech/skywater130/layermap.lua:5: attempt to call a nil value (global 'array').
Is the skywtare130 tech file you provided still viable ? It says that it is from 4 years ago. Also, is it possible to create tech files for gpdk45, 90 or 180 from cadence? It would make it easier to test the tool when I deploy it on the virtuoso server.

[patrickschulz]

Thank you for this report. I fixed the basic function of the skywater130 technology files, although just that the inductor is working. As you said, this file is pretty old and is based on very slim information I have about the process. Please feel free to let me know about more improvements, as I'm not actively working with that node.
For your convenience, here is a cellscript for generating a working inductor:

local inductor = pcell.create_layout("passive/inductor/octagonal", "_inductor", {
    topmetal = -1,
    turns = 3,
    radius = 40000,
    cornerradius = 14000,
    width = 6000,
    separation = 6000,
    extension = 40000,
    viashift = 3000,
    viaoverlapextension = 3000,
    extsep = 6000,
    allow45 = true,
})
return inductor

As you reported this error, you already seem to know how to do this, but for completeness here is the command:
opc --technology skywater130 --export gds --cellscript inductortest.lua
(with opc 0.7.2)
If you are using magic, I could use some help on the format, as the export is currently broken. I don't know how polygons are represented in magic and the inductor cell exports a polygon.

[patrickschulz]

Concerning the generic PDKs: creating the technology files is actually pretty easy, just a bit repetitive. There is an assistant that helps with that (`--techfile-assistant). I tried to make it robust, but its not tested thoroughly. The nice thing about the technology files is that you can gradually extend them if you are missing something.