Advanced Micro Devices Corporation

Kris Martin Holt

Yi Cheng

Zhenhua Liu

A filter has a transfer function. The filter includes a signal input for receiving an input signal and a signal output operatively coupled to the signal input for providing an output signal. A ratio of the output signal to the input signal is equal to the filter's transfer function. The filter also includes a set of control inputs, wherein each control input in the set of control inputs is adapted for providing a digital signal. Each selectable transconductive load in a set of selectable transconductive loads has a transconductance and is operatively coupled to the signal output and a control input in the set of control inputs. The transfer function is set in response to a digital signal provided by at least one control signal in the set of control signals. Each selectable transconductive load is selected in response to at least one control signal in the set of control signals. Accordingly, the value for the transfer function is further dependent upon transconductances provided by selectable transconductive loads that are selected.

Digitally controlled transmission line equalizer

An improved decoder for recovering Non-Return-to-Zero Interface (NRZI) digital data from a multiple layer transition (MLT-3) encoded signal in a 100BASE-TX Ethernet (IEEE Standard 802.3u) uses multiple comparators to minimize jitter in the decoded signal. A CMOS-based biasing circuit receives the differential MLT-3 encoded input signals and control signals from a signal amplitude detection circuit. The biasing circuit adjusts for any DC offset, and also generates offset signals based on respective mid-peak voltage values of the respective differential input signals. Four comparators are then used to detect a prescribed edge transition (e.g., a positive edge) coinciding with the respective mid-peak voltage value in the respective signals. The detected edge transitions are then used by edge decoding logic to generate the NRZI bilevel signal.

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Pleasanton, CA, United States of America

Kris Martin Holt