fanout                                             Specifies the fanout
                                                   value of the driver of an
                                                   input. To specify
                                                   bidirectional I/Os,
                                                   specify the same port
                                                   name for both fanout and
                                                   fanin values.
 fanout_value                                        floating-point value
 [ -g | port_list ]                                  Applies constraint
                                                     globally or to input
                                                     ports in a design unit or
                                                     instance/all inputs at
                                                     the current scope
 [ -maximum ]                                        Specifies an upper limit
                                                     on the actual fanout of
                                                     the driver of an input
                                                     port.
