Categories

Languages

Community › Category: MODELZEN › The error message “definition of model not found” or “undefined model or subcircuit” occurring while generating models using MODELZEN

MODELZEN

The error message “definition of model not found” or “undefined model or subcircuit” occurring while generating models using MODELZEN

SA Support Team Staff 2019-03-08

While generating a model from my circuit using, I encountered the following error message:

When using HSPICE as circuit simulator:

**error** definition of model 'xxx' not found. Please specify a defined model name.

When using Spectre as circuit simulator:

ERROR (SFE-23): The instance 'aaa' is referencing an undefined model or subcircuit, 'xxx'. Either include the file containing the definition of 'xxx', or define 'xxx' before running the simulation.

How can I address this error?

1 Answers
Vote Up 1 Vote Down
Best Answer
SA Support Team Staff 2019-03-08

The error message occurs when the model library defining the devices used in the circuit netlist is not properly included in the HSPICE or Spectre simulation performed by MODELZEN. In order to run a circuit simulation using HSPICE or Spectre, you need to specify one or more model libraries that define the characteristics of the devices used in the circuit, which are typically part of the process design kit (PDK) provided by the foundry. For the information regarding the specific ways of including the model libraries or location of the model library files, please refer to the technology documentations provided by your foundry. For instance, you may use the following statement for HSPICE:

.lib "/path_to_model/models.lib" typ

And for Spectre:

include "/path_to_model/models.scs" section=typ

Also note that it is not uncommon to use more than one .lib or include statements to include the entire model library.

MODELZEN also needs to include the model library in the same fashion when it performs HSPICE or Spectre simulations to extract the circuit or device characteristics. To do so, you can define the proper statements in the dev_model['hspice'] or dev_model['spectre'] of the technology configuration file. For more detailed information, please refer to the Section 4.3 Defining Device Models and Corners in the MODELZEN User's Guide.