Level One Communications, Inc.

Joseph E Heideman

Haim Shafir

Stefan M Wurster

David T Chan

Ralph E Andersson

David S Wong

Cecil Aswell

Daniel L Ray

Cheng-chung Shih

An inter-repeater backplane that allows seamless integration of multiple repeaters into a single hub and wherein each repeater may be swapped out without causing the backplane to crash, hang-up or pass error messages. The mixed signal state machines operate in conjunction with the dual analog, digital collision signaling scheme so that repeaters can be removed from the hub without causing the remaining repeaters in the hub to malfunction. Additional drivers or external glue logic are not needed for arbitration because PORTN and PORTM information is embedded within the backplane signals. Thus, the backplane scheme according to the present invention is completely seamless. The present invention provides a bus of electrically conductive signal lines coupled between repeaters for communicating electrical signals therebetween, collision signaling scheme that uses both analog and digital signals to convey state machine information to adjacent repeaters over the bus, collision force scheme for indicating transmit collision over the bus, monitor scheme for determining when transmit collision and PORTM conditions occur and mixed signal state machines for implementing the functions of the repeaters and controlling the transitions on the backplane. Thus, the unique analog digital backplane combination in conjunction with the repeater/IRB state machine makes bus arbitration unnecessary.

Inter-repeater backplane for allowing hot-swapping of individual

An inter-repeater backplane employs both analog and digital circuitry to convey state machine information to adjacent repeaters thereby allowing seamless integration of multiple repeaters into a single hub without requiring additional drivers or external glue logic. A data path allows the passage of data between multiple repeaters on the inter-repeater backplane and an inter-repeater backplane enable allows individual repeaters to take control of the inter-repeater backplane data bus. An inter-repeater backplane driver enables external bus drivers which may be required in synchronous systems with large backplanes. An inter-repeater backplane clock is used to synchronize multiple repeaters on the inter-repeater backplane. Only two leads (IRCOL and IRCFS) are used to provide transmit and receive collision information. These two leads in conjunction with IRENA also indicate which repeater is receiving data. The transmit and receive collision information is presented on the backplane in a manner that is both analog and digital in nature.

Inter-repeater backplane with mixed signal state machine interconnect

An inter-repeater backplane that may operate in either a synchronous or asynchronous mode for data transmission. The inter-repeater backplane includes a bus of electrical signal conductors coupled between repeaters for communicating electrical signals and data transmission mode detector for determining whether to transmit data synchronously or asynchronously. Data is recovered from a received data packet and is reframed for transmission across the inter-repeater backplane. According to which mode of data transmission is selected, the data is then retimed and transmitted across the backplane. In the synchronous mode of data transmission, the data is synchronized with the system clock. When the asynchronous mode of data transmission is selected, the data is transmitted asynchronously with respect to the system clock. In the asynchronous mode, the recovered data is timed with a clock signal associated with the transmitting repeater.

Inter-repeater backplane with synchronous/asynchronous dual mode

A data communication system employing predetermined equalized waveforms for transmit equalization is disclosed. Serial NRZ data is received from a network controller and utilized to select from memory its equivalent as predistorted and filtered Manchester encoded data. Predetermined waveforms in memory are representative of the analog waveform produced when predistorted digital Manchester encoded data is passed through a high order transmit filter. Data from memory drives a digital to analog converter (DAC) to reconstruct the waveforms into analog form. A line driver having an integrated single pole low pass filter impresses the equalized waveform on to the transmission line.

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Orangevale, CA, United States of America

Joseph E Heideman