Hewlett Packard Enterprise Development LP

David Ritter Thomas

Kit MacCarthy Morton

Jason Douglas Jung

Mauricio Madiedo

Daniel Alan Berkram

William Lee

James Donald Regan

Alexander David Wilson

Laurel Abeyta

Leah Rozewski

Jeffrey Zenning Chow

Michael Alex Schroeder

Examples described herein relate to a receiver training method. To configure a static gain for at least one static gain amplifier and a target amplitude for a dynamic gain amplifier, a dynamic gain adjustment is disabled and the dynamic gain amplifier is configured to apply a predetermined fixed gain to the static gain amplified signal to generate a test signal. Furthermore, an effective static gain magnitude for at least one static gain amplifier and an effective amplitude for the test signal are determined based on a link performance metric. The static gain is set to the effective static gain magnitude, and a target amplitude for the dynamic gain amplifier is set to the effective amplitude. Then, the dynamic gain adjustment may be enabled to maintain an amplitude of a dynamic gain amplified signal at an output of the dynamic gain amplifier at the target amplitude by varying the dynamic gain.

Gain and target amplitude tuning in a receiver

Examples described herein relate to a method and a system for removing the common-mode current. The receiver includes a photodetector, a common-mode adjustment circuit, an analog front-end, an eye scan circuit, and a control unit. The photodetector generates an input photocurrent responsive to a received optical signal. The common-mode adjustment circuit generates an adjusted input current based on the input photocurrent. The analog front-end generates a differential voltage based on the adjusted input current. Based on the differential voltage, the eye scan circuit generates an eye scan information defining a first outer eye and a second outer eye in an eye diagram. The control unit tunes the common-mode adjustment circuit based on a relative height metric of a first height of the first outer eye and a second height of the second outer eye to remove a portion of the common-mode current from the input photocurrent.

Common-mode current adjustment in a receiver

Examples relate to determining a sampling threshold of a receiver (e.g., SERDES receiver). In particular, the examples relate to determining an updated sampling threshold of the receiver based on a reference sampling threshold of the receiver. A controller may determine the reference sampling threshold based on the training sequence and determine an upper voltage level and a lower voltage level of a voltage range based on the reference sampling threshold of the receiver. The controller then narrows the voltage range based on upper voltage accumulated hit rate and a lower voltage accumulated hit rate to determine the updated sampling threshold of the receiver.

Determining sampling thresholds of SERDES receivers

According to an example, a transmitter transmits a plurality of optical signals of multiple wavelengths via an optical link to a receiver. An optical link tuner coupled to the optical link groups the plurality of optical signals into a first group of optical signals and a second group of optical signals, where the first group of optical signals has a first wavelength range and the second group of optical signals has a second wavelength range. The optical link tuner adjusts link tuning parameters associated with the first group of optical signals during a first phase, such that the second group of optical signals is propagated to the receiver without modifications to link tuning parameters associated with the second group, where during the first phase the receiver is to detect unplugging of the optical link based on the second group of optical signals.

Optical interconnects

Examples described herein relate to calibration of an optical communications link. Data signals received over the optical communications link are measured to obtain an eye scan. A height of an upper eye region and a height of a lower eye region are compared in the eye scan. A common mode calibration value is adjusted based on any difference in the heights. A common mode adjustment circuit is then controlled based on the common mode calibration value. The common mode adjustment circuit is configured to remove a direct current bias within a receiver for the optical communications link.

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Fort Collins, CO, United States of America

David Ritter Thomas