How are the CDL and SPICE libraries created and what are they intended to be used for? Is the CDL generated from schematic designs and SPICE extracted from the layouts?

@Mitch Bailey: In my understanding/experience, CDLs are converted from equivalent spectre sources (more or less text-processed), and, yes, SPICE is layout-extracted using magic. @Tim Edwards is probably the one you're looking for though.

@Mitch Bailey: Generally speaking, CDL is what we got for netlists from SkyWater. SPICE netlists have been made by reading GDS into magic, extracting, and writing out ngspice-compatible SPICE.

@Ahmed Ghazy @Tim Edwards Thanks for the responses. In my opinion, since the SPICE netlists are created from the GDS, what we really should be using for device level LVS is the CDL library. But the SPICE libraries are easier to use at the moment.

@Mitch Bailey: I completely agree with you.