Abstract: A multi-port LAN switch is provided that enables attached network devices to both communicate directly and to insert into a token-ring network through an attached concentrator. Each port of the multi-port LAN switch has a first transformer, a second transformer, and a switching system. The first transformer has a first winding connected to a first connection of the port. The second transformer has a first winding connected to a second connection of the port. The switching system switches to a port mode or an adapter mode as a function of a mode signal transmitted to the port In the adapter mode, the switching system connects a second winding of the first transformer to a transmitter circuit in the port, and its connects a second winding of the second transformer to a receiver circuit in the port.

Abstract: A modem having an interactive clearing circuit that provides the facility for the modem to mix interleaved and non-interleaved writes to a FIFO without timing problems or data transfer problems associated with the prior art. The circuit includes a self-clearing error bit circuit that clears the error bits of an interleaved write from the LSR after each FIFO write. In one embodiment, the clearing circuit provides dummy bits to the LSR upon each controller write to the FIFO. This prevents error bits associated with previous interleaved writes from becoming associated with subsequent non-interleaved writes.