Parameters and Defparams in Verilog In

Modules containing parameters and defparams are treated as structural. However, functional views are created for the following exceptional cases:

• If the datatype of the value for parameter or defparam is other than decimal integer values, real values, and strings.
• If the parameter or defparam contains any arithmetic or logical expressions.
• If the parameter or defparam contains any identifier defined earlier by parameter statement.
• If parameters are used in the port declaration or net declaration.
• The inline parameter instantiation is used, but the source file containing the module definition is not given.