Marvell International Limited

Oak Technology, Inc.

Timothy Hu

Lei Wu

Russell R Newcomb

A circuit including delay stages, gain stages, and a summer. The delay stages are configured to provide delayed versions of a first signal. The gain stages are configured to receive the delayed versions of the first signal. Each of the gain stages provides an amount of gain for a corresponding one of the delayed versions of the first signal. The delay stages and the gain stages are configured to provide pre-emphasis to the first signal. The summer is configured to output a second signal based on the delayed versions of the first signal. The second signal includes the pre-emphasis.

Apparatus and method for providing pre-emphasis to a signal

A device is provided and includes a multiplexer that receives signals and generates an output signal based on a selected one of the signals. The output signal includes frequencies and has a respective signal magnitude at each of the frequencies. A control circuit determines gain values. A transmitter provides pre-emphasis to the output signal to offset a characteristic of a channel, and transmits the output signal with the pre-emphasis on the channel. The transmitter, in providing the pre-emphasis: provides delayed versions of the output signal, where each of the delayed versions of the output signal has a different amount of delay than other delayed versions of the output signal; and amplifies each of the delayed versions of the output signal based on a respective one of the gain values such that certain ones of the signal magnitudes are amplified, and other ones of the signal magnitudes are attenuated.

Device with pre-emphasis based transmission

A transmitter including an analog front end configured to receive a serial signal; a control circuit configured to generate a first gain signal and a second gain signal based on a characteristic of a serial channel; a first amplifier is configured to amplify the serial signal to generate a first amplified signal based on the first gain signal; a first delay device configured to delay the serial signal to generate a first delayed signal; a second amplifier configured to amplify the first delayed signal to generate a second amplified signal based on the second gain signal; and at least one summer is configured to sum the first amplified signal and the second amplified signal to generate an output signal. The output signal is transmitted on the serial channel.

Programmable pre-emphasis circuit for serial ATA

A high-speed serial ATA physical layer includes a serial ATA control circuit. A serial ATA multiplexer outputs one of a plurality of serial ATA signals that is selected by the serial ATA control circuit. A serial ATA analog front end provides a first gain and pre-emphasis to the selected one of the plurality of serial ATA signals. The pre-emphasis alters a transmission characteristic of the selected one of the plurality of serial ATA signals.

A high-speed serial ATA physical layer transmits data over a communications medium using a serial ATA protocol. A serial ATA control circuit controls operation of the serial ATA physical layer. A serial ATA multiplexer outputs a serial ATA signal and has a plurality of input lines for receiving input data and a control input that communicates with the serial ATA control circuit. A serial ATA analog front end includes a first differential driver that communicates with the serial ATA multiplexer and provides a first gain to the serial ATA signal and a serial ATA pre-emphasis circuit that provides pre-emphasis to the serial ATA signal to alter a transmission characteristic of the serial ATA signal.

In a video system in which a video signal source transmits a video signal to a receiver over a transmission line, a method of maintaining a desired voltage level from the video signal source includes the steps of monitoring the level of voltage at the output of the video signal source, and adjusting an input to the video signal source as necessary in order to maintain a desired level of voltage. Thus, when the impedance of the transmission line and receiver change, the output voltage from the video signal source is maintained at a desired level without clipping of the signal when the video signal source is overdriven.

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Los Altos, CA, United States of America

Timothy Hu