Silicon Graphics, Incorporated

Other

Frank Nolan Cornett

Philip Nord Jenkins

John F DeRyckere

Gregory Michael Thorson

Joseph Martin Placek

Terrance L Bowman

Rodney A Ruesch

Nan Ma

Brian T Hillert

Nicholas G Demas

Michael R Arneson

James G Demas

John G Demas

Leonidas G Demas

A system and method of reducing skew between a plurality of signals transmitted with a transmit clock is described. Skew is detected between the received transmit clock and each of received data signals. Delay is added to the clock or to one or more of the plurality of data signals to compensate for the detected skew. The delay added to each of the plurality of delayed signals is updated to adapt to changes in detected skew.

System and method for adaptively deskewing parallel data signals relative to a clock

The present invention is directed toward a communications channel comprising a link level protocol, a driver, a receiver, and a canceller/equalizer. The link level protocol provides logic for DC-free signal encoding and recovery as well as supporting many features including CRC error detection and message resend to accommodate infrequent bit errors across the medium. The canceller/equalizer provides equalization for destabilized data signals and also provides simultaneous bi-directional data transfer. The receiver provides bit deskewing by removing synchronization error, or skewing, between data signals. The driver provides impedance controlling by monitoring the characteristics of the communications medium, like voltage or temperature, and providing a matching output impedance in the signal driver so that fewer distortions occur while the data travels across the communications medium.

Method and apparatus for communicating computer data from one point to another over a communications medium

A system and method of reducing skew between a plurality of signals transmitted with a transmit clock is described. Skew is detected between the received transmit clock and each of received data signals. Delay is added to the clock or to one or more of the plurality of data signals to compensate for the detected skew. Each of the plurality of delayed signals is compared to a reference signal to detect changes in the skew. The delay added to each of the plurality of delayed signals is updated to adapt to changes in the detected skew.

A variable communication systems comprising a plurality of transceivers and a control circuit connected to the transceivers to configure the transceivers to operate in a bi-directional mode and a uni-directional mode at different times using different transfer methods to transfer data.

Variable mode bi-directional and uni-directional computer communication system

Circuitry that provides additional delay to early arriving signals such that all data signals arrive at a receiving latch with same path delay. The delay of a forwarded clock reference is also controlled such that the capturing clock edge will be optimally positioned near quadrature (depending on latch setup/hold requirements). The circuitry continuously adapts to data and clock path delay changes and digital filtering of phase measurements reduce errors brought on by jittering data edges. The circuitry utilizes only the minimum amount of delay necessary to achieve objective thereby limiting any unintended jitter. Particularly, this programmable differential delay circuit with fine delay adjustment is designed to allow the skew between ASICS to be minimized. This includes skew between data bits, between data bits and clocks as well as minimizing the overall skew in a channel between ASICS.

Programmable differential delay circuit with fine delay adjustment

A distance measuring system includes a base unit and a remote unit. The remote unit transmits a first radio frequency signal to the base unit. The base unit transmits a second radio frequency signal upon receipt of the first radio frequency signal from the remote unit. The remote unit measures the time between transmission of the first radio frequency signal and receipt of the second radio frequency signal, thereby enabling the distance between the base unit and the remote unit to be ascertained. The accuracy of the measured distance may be improved by averaging additional measurement cycles.

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Chippewa Falls, WI, United States of America

Frank Nolan Cornett