drive                                              Specifies the drive
                                                   factor of the driver of
                                                   an input port. To specify
                                                   bidirectional I/Os,
                                                   specify the same port
                                                   name for both drive and
                                                   load values.
 drive_value                                         floating-point value
 [ -g | port_list ]                                  Applies constraint
                                                     globally or to input
                                                     ports in a module or
                                                     instance/all inputs at
                                                     the current scope
