Hewlett-packard Company

Pericom Semiconductor Corporation

Daniel J Dove

Alan R Albrecht

Michael P Spratt

Joseph A Curcio

Steven H Goody

Bruce W Melvin

Simon Edwin Crouch

Yao Tung Yen

Jonathan Jedwab

Alex Chi-Ming Hui

En-Ling Feng

An electronic communications network technology, referred to as 100BASE-TD, offers full duplex operation and robust performance on marginal CAT5 wiring. It highly leverages 100BASE-TX functional blocks and is very complementary to 100BASE-TX, for example with regard to such 100BASE-TX features as auto-negotiation. In particular, the invention provides a carrierless IDLE that requires very low power during ambient operation.

High speed physical layer for CSMA/CD systems

Apparatus is disclosed for automatically configuring network media connections of end node interfaces as well as node interfaces that operate as a hub, a switch or a repeater in a Local Area Network. The apparatus utilizes a pseudo-random sequencer to prevent lock step operation whereby the connections cannot be properly configured.

Apparatus for automatically configuring media connectors of a node interface device

A network node is connectable to a network. The node includes a physical media access sublayer. The physical media access sublayer includes a link monitor state machine. The link monitor state machine includes an evaluate link state, an evaluate carrier state, an increment criteria state and a link down state. In the evaluate link state, an idle timer is started. The evaluate carrier state is entered from the evaluate link state when a carrier event is detected before expiration of the idle timer. In the evaluate carrier state, a valid carrier timer is started. The increment criteria state is entered from the evaluate carrier state if a status error is detected or if the carrier event completes before expiration of the valid carrier timer. In the increment criteria state, a false carrier count is incremented. The link down state is entered from the increment criteria state if the false carrier count, after being incremented, is equal to a false carrier count limit.

Link monitor state machine

Apparatus for automatically configuring network media connections

A micro-relay replaces electromechanical and solid-state opto-isolated relays in a computer network. The micro relay is an integrated circuit containing several bus switches in parallel. Each bus switch can make or break a connection. The bus switch is an n-channel MOS transistor with the source and drain connected to different network busses. A bus enable input causes the connection to be made or broken. The bus enable input is separately buffered for each gate of each MOS transistor to prevent crosstalk between bus switches. Since the MOS transistor stops conducting when the source is at a voltage level of the power-supply voltage minus the threshold voltage, a boosted voltage is applied to the gate of the MOS transistor to allow conduction even when the source is at the power-supply voltage level. The boosted voltage is generated by a charge pump. A substrate bias is applied to the transistors to prevent crosstalk from undershoots. Buffers for the gates of the bus switches are inverters that are connected to the boosted voltage rather than the power supply, and to the substrate voltage rather than ground. Thus the gates are driven to the boosted voltage or to the substrate voltage. For reduced crosstalk when the connection is broken, two transistors in series are used for each bus switch, with the intermediate node being pulled to ground when the bus switch is disabled, shielding the two transistors and the two network busses on opposite sides of the bus switch. An external capacitor is used to reduce noise from the charge pump.

Parallel micro-relay bus switch for computer network communication with

A method for transmitting data packets, grouped as data octets, over a LAN having a central hub linked to each of a plurality of network nodes via a physical medium consisting of four pairs of unshielded twisted pair (UTP) cable. The transmission method sequentially divides the data into data quintets. The quintets are then arranged into blocks of data quintets and sequentially distributed into four individual serial code streams. The four serial code streams are sequentially scrambled to produce four streams of randomized quintets. The randomized data streams are sequentially block encoded into 6-bit symbol data which are then transmitted using NRZ modulation across the network by transmitting each data stream over one of said pairs of cable.

High speed data transfer over twisted pair cabling

A method provides for a first network node in a plurality of network nodes to transmit a data packet to a hub. The hub and the network nodes are interconnected within a local network system. Control signals are exchanged between the first network node and the hub. The exchange of control signals is done in a first signal frequency range. A data packet is sent from the first network node to the hub. The data packet is sent using data signals within a second signal frequency range. The first signal frequency range and the second signal frequency range do not overlap.

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Applegate, CA, United States of America

Daniel J Dove