公开(公告)号：US11909565B2

公开(公告)日：2024-02-20

申请号：US17879611

申请日：2022-08-02

Applicant: Cadence Design Systems, Inc.

Inventor： Anirudha Shelke ,  Ashwin S. Madhavakaimal ,  Kiran Baby

IPC: H04L25/03

CPC classification number: H04L25/03057

Abstract: Decision feedback equalization (DFE) is used to help reduce inter-symbol interference (ISI) from a data signal received via a band-limited (or otherwise non-ideal) channel. In embodiment, a single-ended receiver trains DFE coefficients and the slicer reference voltage to improve the received eye height. The process for training avoids many whole range sweeps thereby shortening training time. A custom data pattern that includes low-frequency (DC with respect to DFE) and high-frequency (AC with respect to DFE) worst cases is used for training in a closed loop manner. Negative DFE is used to measure the AC height of the data. Positive DFE is used to find the DC height of the data pattern.

公开(公告)号：US11810633B2

公开(公告)日：2023-11-07

申请号：US17460701

申请日：2021-08-30

Applicant: Cadence Design Systems, Inc.

Inventor： Ashwin S. M. ,  Anirudha Shelke ,  Navin Kumar Mishra ,  Phalguni Bala ,  Younus Syed ,  Kiran Baby ,  Sudhir Kumar Katla Shetty

IPC: G11C7/10 ,  G11C29/36 ,  G11C7/22 ,  G11C29/50

CPC classification number: G11C29/36 ,  G11C7/22 ,  G11C29/50004 ,  G11C2207/2254

Abstract: In a receiver having at least a first equalizer and a sampler, a calibration module jointly calibrates a reference voltage and one or more equalizer coefficients. For each of a set of test reference voltages, an equalizer coefficient for the first equalizer may be learned that maximizes a right eye boundary of an eye diagram of a sampler input signal to a sampler of the receiver following the equalization stage. Then, from the possible pairs of reference voltages and corresponding optimal equalizer coefficients, a pair is identified that maximizes an eye width of the eye diagram. After setting the reference voltage, the first equalizer coefficient may then be adjusted together with learning a second equalizer coefficient for the second equalizer using a similar technique.