公开(公告)号：US09184906B1

公开(公告)日：2015-11-10

申请号：US14492420

申请日：2014-09-22

Applicant: ORACLE INTERNATIONAL CORPORATION

Inventor： Jihong Min ,  Dawei Huang ,  Jianghui Su ,  Hongtao Zhang

IPC: H04L7/00

CPC classification number: H04L7/0334 ,  H04L7/0016 ,  H04L7/0062 ,  H04L7/0087

Abstract: Embodiments include systems and methods for using generalized pulse amplitude modulation (PAM-X) signaling with an at-rate not-return-to-zero (NRZ) clock data recovery (CDR) system. Some implementations include dual-mode signaling for an at-rate CDR (e.g., using standard NRZ signaling at lower operating frequencies and pseudo-NRZ signaling derived from PAM-X signaling at higher operating frequencies. Embodiments derive an apparent direction of signal transition from PAM-X signaling. The direction can be used to calculate pseudo-NRZ values. For example, when the PAM-X signal transitions in an upward direction, a pseudo-current NRZ value and a pseudo-previous NRZ value of ‘−1’ and ‘+1’ can be generated, respectively. An at-rate NRZ CDR can use the pseudo-NRZ values and a derived error value to make an offset determination. The offset determination can then be used to offset a generated clock signal in the CDR system.

Abstract translation: 实施例包括用于使用通率不归零（NRZ）时钟数据恢复（CDR）系统的广义脉冲幅度调制（PAM-X）信令的系统和方法。 一些实现方案包括用于速率CDR的双模式信令（例如，在较低工作频率下使用标准NRZ信令和在较高工作频率下从PAM-X信令导出的伪NRZ信令。实施例导出来自PAM的信号转换的明显方向 -X信号，该方向可用于计算伪NRZ值，例如，当PAM-X信号向上转换时，伪电流NRZ值和伪前NRZ值为“-1”， 可以分别产生'+1'，高速NRZ CDR可以使用伪NRZ值和派生误差值进行偏移确定，然后可以使用偏移确定来补偿CDR中产生的时钟信号 系统。