Holiday? What's a holiday? Thank you for bringing this to my attention. I discovered that the routine names for the inductor devices in sky130A.tcl were incorrect, causing the error. I just corrected this in open_pdks:

commit e4b453599ad0b112e90c89220145c8219dda3cb0

on opencircuitdesign.com, open_pdks version 1.0.262. It is true, however, that there is a huge disconnect in the PDK with respect to inductors. There are layouts for the ones in the parameterized cell menu in magic called

test_coil1

,

test_coil2

, and

test_coil3

. There are SPICE models for three inductors called

ind_03_90

,

ind_05_125

, and

ind_05_220

. I have not been able to validate if the three models correspond to the three test coils. It appers that the values

xx

and

yy

in the name

ind_xx_yy

refer to the number of turns and the radius (?). The number of turns seems to correspond to the test coil layouts, and the

yy

value is proportional to the radii of those layouts, but not equal. So I have held off on equating the layouts and models with each other in the PDK installation. The other issue is that there was one specific variant of the older s8 process that was said to support inductors and had a 3-metal stack with a thick metal3. So there is the additional uncertainty as to whether the test coil models are even appropriate to sky130. Clearly, one would prefer to create coils on the topmost metal, so for sky130, that would mean metal5 inductors. I have one layout of a metal5 inductor from SkyWater called

xind4_01

that comes from an LVS verification layout but has no model anywhere, making it somewhat useless except maybe as a reference for how to do an inductor layout. Thread in Slack Conversation