loose-electron wrote on Sep 18th, 2011, 1:45pm:Verilog A or AMS is generally used for functional level models, not transistor level models.
Jerry - You've missed the revolution in transistor-level compact modeling: almost all the latest transistor models (PSP, BSIMSOI, VBIC, Mextram, Hicum, ... and soon BSIM6) are written/developed in Verilog-A. Spectre, HSpice, Eldo, etc. all have Verilog-A compilers. The users can then modify the source code to add new equations / model features.
That said, it is Verilog-A; I can't recall ever seeing a compact model written in VHDL-AMS, other than maybe a basic diode as an example. Verilog-AMS added a bunch of features to the language in LRM 2.2 to make compact modeling easier, and that's where the developers have gone.