Hi. Just getting used to SW130 and want to browse through the model file. I see in the opening page the TT models can be found at: .lib $::SKYWATER_MODELS/sky130.lib.spice tt Then in the xschemrc file I see the variable SKYWATER_MODELS is set as: set SKYWATER_MODELS ${PDK_ROOT}/${PDK}/libs.tech/combined However, when I navigate to pdk/sky130A/libs.tech, I dont see a dir called "combined" (see screenshot). Basically, I just want to look through file "sky130.lib.spice" and view the various sections (tt, sf, fs, ff, ss). Where can I actually find it and should I be seeing a "combined" dir?

If you don't have a directory

combined

in

libs.tech

then you have an older PDK.

the combined directory is rather new, if you don't see it just rebuild open_pdks. In the xschemrc there is a commented line to use the old model files: # set SKYWATER_MODELS ${PDK_ROOT}/${PDK}/libs.tech/ngspice Uncomment this line and comment the other referring to combined/

An older PDK will have the original device models, which were characterized tightly around specific widths and lengths. But they work, and you can find them in the

ngspice

subdirectory instead of

combined

.

Interesting. So from the screenshot, you can see I installed the Feb 11th version using volare and not the pre-release versions. Should I just install the latest pre-release version (7th May) to see the combined folder?

I really am not sure why neither the

ngspice

nor the

combined

directories show up under

libs.tech

. @donn --- Do you have any idea?

would it be a volare issue? should I try installing from open_pdk instead?

Not unlikely that I didn't simply miss a flag or two while building from Volare. Yeah, I'd recommend installing from

open_pdks

while I investigate.

no problem, it will give me experience building from open_pdks. I guess I should uninstall the volare version to save space. What is the command for this?

that just uninstalls the enabled pdk right? and not volare?

yeah

Just after installing from open_pdk and can confirm I now see the combined dir, as shown below. One question, probably for @Stefan Schippers: I needed to create my root variable as: export PDK_ROOT=/home/slice/pdk/SW130/share/pdk Do I also need to create the variable: export PDK=sky130A? I had to do this when installing through volare. I presume I still need to include it so that my sims are run using the correct flavor of the pdk?

@Diarmuid Collins yes, also set PDK, if you don't xschem assumes sky130A

great. so sky130a seems the default. thanks