# US 5,703,883 A · Expandable repeater controller > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,703,883 A - Document ID: US5703883A - Status: Granted - Kind: A - Application number: 08/536,935 - Filed: 1995-09-29 - Granted: 1997-12-30 - Earliest claimed: 1995-09-29 - Assignees: United Microelectronics Corp. - Inventors: Jone-Jane Chen - Web page: https://patentgrep.com/patent/US5703883A ## CPC - H04L 12/44: Star or tree networks - H04B 3/36: Repeater circuits (H04B3/58 takes precedence) - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - H04B: TRANSMISSION ## Abstract An expandable repeater controller for a local area network. The expandable repeater controller has with three expansion ports. An interface signal is transmitted through an EXPOUT port when the expandable repeater controller is going to transmit data through a DAT port. The interface signal is received through an EXPIN port if the expandable repeater controller is required to receive data through DAT port. The operational status of the expandable repeater controller is determined by logic levels of ports EXPOUT and EXPIN. The repeater controller of the invention is provided with an expansion port circuit which includes means for generating synchronous clock signals, means for dealing with data collision conditions and means for transmitting and receiving data as well as the interface signals. The repeater controller further includes an arbiter if more than two repeater controllers are connected for expansion. Two repeater controllers of the present invention are expanded by connecting the EXPOUT port of one controller to the EXPIN port of the other controller and connecting their DAT ports together. Three or more repeater controllers of the present invention are expanded by connecting their EXPOUT and EXPIN ports to the arbiter and connecting their DAT ports together. ## Claims ### Claim 1 An expandable repeater controller for connecting workstations, comprising: a plurality of transceivers for data communication with said workstations; a decoder for decoding data received from said transceivers; an encoder for encoding data sent to said transceivers; a state machine for controlling operations of said transceivers; and an expansion port circuit, controlled by said state machine, for receiving decoded data from said decoder and sending data to said encoder, said expansion port circuit including means for transmitting over a first expansion port an outgoing interface signal when said expandable repeater controller is going to transmit data, means for receiving an incoming interface signal over a second expansion port when said expandable repeater controller is requested to receive data and means for transmitting and receiving data over a third expansion port. ### Claim 2 (depends on 1) The expandable repeater controller of claim 1, further comprising means to broadcast a jam signal to said transceivers when said first expansion port transmits said outgoing interface signal and said second expansion port receives said incoming interface signal at the same time. ### Claim 3 A dual expandable repeater controller system for connecting workstations, said system comprising a pair of controllers, each one of said pair including: a plurality of transceivers for data communication with said workstations, a decoder for decoding data received from said transceivers; an encoder for encoding data sent to said transceivers; a state machine for controlling operations of said transceivers; and an expansion port circuit, controlled by said state machine, for receiving decoded data from said decoder and sending data to said encoder, said expansion port circuit including means for transmitting over a first expansion port an outgoing interface signal when said expandable repeater controller is going to transmit data, means for receiving an incoming interface signal over a second expansion port when said expandable repeater controller is requested to receive data and means for transmitting and receiving data over a third expansion port; wherein said first expansion port of a first controller of said pair is connected to said second expansion port of a second controller of said pair, wherein said second expansion port of said first controller is connected to said first expansion port of said second controller, and wherein said third expansion port of said first controller is connected to said third expansion port of said second controller. ### Claim 4 A triple expandable repeater controller system for connecting workstations, said system comprising: three controllers, each one of said controllers including: a plurality of transceivers for data communication with said workstations; a decoder for decoding data received from said transceivers; an encoder for encoding data sent to said transceivers; a state machine for controlling operations of said transceivers; and an expansion port circuit, controlled by said state machine, for receiving decoded data from said decoder and sending data to said encoder; said expansion port circuit including: means for transmitting over a first expansion port an outgoing interface signal when said expandable repeater controller is going to transmit data; means for receiving an incoming interface signal over a second expansion port when said expandable repeater controller is requested to receive data; and means for transmitting and receiving data over a third expansion port; and an arbiter coupled to each of said controllers, said arbiter having three input terminals and three output terminals, said input terminals and said output terminals of said arbiter being represented as I1, I2, I3, O1, O2, and O3, respectively, wherein each first expansion port of said controllers is coupled to a respective input terminal, each second expansion port is coupled to a respective output terminal, and each third expansion port is coupled together, said arbiter including means for satisfying: O1=I2+I3, O2=I1+I3 and O3=I1+I2. ### Claim 5 A multiple expandable repeater controller system for connecting workstations, said system comprising: a plurality of controllers, each one of said plurality of controllers including: a plurality of transceivers for data communication with said workstations, a decoder for decoding data received from said transceivers, an encoder for encoding data sent to said transceivers, a state machine for controlling operations of said transceivers, and an expansion port circuit, controlled by said state machine, for receiving decoded data from said decoder and sending data to said encoder, said expansion port circuit including: means for transmitting over a first expansion port an outgoing interface signal when said expandable repeater controller is going to transmit data; means for receiving an incoming interface signal over a second expansion port when said expandable repeater controller is requested to receive data; and means for transmitting and receiving data over a third expansion port; and an arbiter coupled to each of said controllers, said arbiter having a plurality of input terminals and a plurality of output terminals, said input terminals and said output terminals of said arbiter being represented as I1, I2, I3, . . . , I(N-1), IN, O1, O2, O3, . . . , O(N-1) and ON, respectively, wherein each first expansion port of said controllers is coupled to a respective input terminal, each second expansion port is coupled to a respective output terminal, and each third expansion port is coupled together, said arbiter including means for satisfying: ______________________________________ O1 = I2 + I3 + I4 + . . . + I (N - 1) + IN, O2 = I1 + I3 + I4 + . . . + I (N - 1) + IN, O3 = I1 + I2 + I4 + . . . + I (N - 1) + IN, . . O (N - 1) = I1 + I2 + I3 + . . . + IN, and ON = I1 + I2 + I3 + . . . + I (N - 1). ______________________________________ ### Claim 6 (depends on 1) The expandable repeater controller of claim 1, wherein said interface signal is a signal of high logic level.