Parameters are constant values.

Syntax:

parameter parameter_name = constant_expression;

Description:

Parameters are constants. It is not allowed to modify parameter values at runtime. A parameter value can be changed at compile time using defparam, or when a module containing parameters is instanced.

The constant expression can contain previously declared parameters. When changes are detected on the previously declared parameters, all parameters that depend on this value are automatically updated.

Example:

parameter Size = 4;
parameter Number = 3.82;
parameter ClkCycle = Frequency / 2; 

See also:

Instantiation