The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.

The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.

Date of Patent:
Apr. 30, 2024

Filed:

Nov. 28, 2022
Applicant:

International Business Machines Corporation, Armonk, NY (US);

Inventors:

Michael B. Spear, Round Rock, TX (US);

Daniel Mark Dreps, Georgetown, TX (US);

Erik English, Salt Point, NY (US);

Jieming Qi, Austin, TX (US);

Michael Sperling, Poughkeepsie, NY (US);

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H04L 27/00 (2006.01); H04L 27/36 (2006.01);
U.S. Cl.
CPC ...
H04L 27/364 (2013.01); H04L 27/0014 (2013.01); H04L 2027/0018 (2013.01);
Abstract

An enhanced quadrature receive serial interface circuit and methods are provided for calibrating the quadrature receive serial interface circuit. A quadrature receive serial interface circuit comprises a first phase rotator and a second phase rotator generating quadrature clocks of identical frequency. Calibration of the quadrature receive serial interface circuit uses a pseudo random bit sequence (PRBS) received by the quadrature receive serial interface circuit. For calibration, one-half of the received PRBS bits are sampled and the phase rotator generating in-phase 0° and 180° clock signals is adjusted to center the data eye for the sampled half of the PRBS bits. Then all data bits (even and odd data bits) of the received PRBS bits are sampled and the phase rotator generating quadrature phase 90° and 270° clock signals is adjusted to center the data eye of all data bits of the PRBS bits to complete calibration.


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