System and method for providing slicer level adaption

• US 7,248,640 B2
• Filed: 08/16/2002
• Issued: 07/24/2007
• Est. Priority Date: 08/17/2001
• Status: Active Grant

• Current Assignee: Synopsys Incorporated
• Original Assignee: Synopsys Incorporated
• Inventors: Gorecki, James, Yang, Yaohua, Martin, David A.
• Primary Examiner(s): Lugo; David B.
• Application Number:
  US10/222,073
• Publication Number:
  US 20030035497A1
• Time in Patent Office: 1,803 Days
• Field of Search: 375/286, 375/287, 375/317
• US Class Current: 375/287
• CPC Class Codes: H04L 25/4917 using multilevel codes
• CPC Class Codes: H04L 27/08 Amplitude regulation arrangements

Abstract

The present invention relates in general to a method, apparatus, and article of manufacture for providing high-speed digital communications through a communications channel. In one aspect, the present invention employs an automatic slicer level adaption to enhance the performance of a high speed communications system.

Claims

1. A reference generator circuit for a receiver module coupled to a digital communications channel, the reference generator circuit comprising:

a reference level generation module that generates an adjustable reference level within the receiver module;

an error measurement module, coupled to the reference level generation module, to determine an error statistic based upon a comparison between a received signal and a desired signal, wherein the error statistic is collected using a sign of a recovered datum and a sign of an error; and

wherein the reference level generation module uses the error statistic to control the magnitude of the adjustable reference level.

2. The reference generator circuit according to claim 1, wherein a range of signal values is determined as corresponding to the received signal using a maximum reference level and minimum reference level;

and

the maximum reference level and minimum reference level are adjusted using the error statistic collected by the error measurement module.

3. The reference generator circuit according to claim 2, wherein adaption of the maximum reference level and minimum reference level can be performed without training data during an initialization process.

4. The reference generator circuit according to claim 2, wherein the maximum reference level and minimum reference level magnitude are externally set to a predetermined value.

5. A reference generator circuit according to claim 2, wherein spacing between reference levels is non-uniform.

6. The reference generator circuit according to claim 5, wherein a performance criteria for setting non-uniformity between ranges of signal values is a measure of a bit-error rate (BER) for the receiver module.

7. The reference generator circuit according to claim 1, wherein a summation is determined that includes a product of the sign of the recovered datum and the sign of the error.

8. The reference generator circuit according to claim 1, wherein

the reference level generation module generates a plurality of adjustable reference levels and

spacing between reference levels is non-uniform.

9. The reference generator according to claim 8, wherein the non-uniformity is asymmetric.

10. A method for a reference generator circuit for a receiver module coupled to a digital communications channel, comprising:

generating an adjustable reference level, within the receiver module, using a reference level generation module;

determining an error statistic, within an error measurement module coupled to the reference level generation module, based upon a comparison between a received signal and a desired signal, wherein the error statistic is collected using a sign of a recovered datum and a sign of an error; and

adjusting the magnitude of the adjustable reference level in response to the error statistic.

11. The method of claim 10, further comprising:

determining a range of signal values as corresponding to the received signal using a maximum reference level and minimum reference level; and

adjusting the maximum reference level and minimum reference level using the error statistic collected by the error measurement module.