When the frame filter is selected with no management interface, only a subset of its functionality is available. Because there is no user access to internal registers it is not possible to update the configurable frame filters, these are therefore not generated as part of the core. However, the basic Destination Address filtering is still available and enables the MAC to identify/filter the Broadcast address, a User supplied Pause/Unicast Address and the Special Pause Multicast Address. In this configuration, it is assumed that the user-supplied Pause address is the same as the MAC Unicast address. A packet matching this filter is only treated as a pause frame if it meets all other criteria to identify a pause frame.