When should I use the [Add Submodel] keyword in an IBIS File?

Description Whenever a reference submodel is added to an existing model. The [Add Submodel] keyword is invoked within a model to add the functionality that is contained in the submodel or list of submodels in each line that follows. The first column contains the submodel name. The second column contains a submodel mode under which the submodel is used If the top-level model type is one of the I/O or 3-state models, the submodel mode may be 'Driving', 'Non-Driving', or 'All'. For example, if the submodel mode is 'Non-Driving', then the submodel is used only in the high-Z state of a 3-state model. Set the submodel mode to 'All' if the submodel is to be used for all modes of operation. The submodel mode cannot conflict with the top-level model type. For example, if the top-level model type is an Open or output type, the submodel mode cannot be set to Non-Driving. Similarly, if the top-level model type is Input, the submodel mode cannot be set to Driving.