Memory Error Correction Using Syndrome Computation for LDPC Decoding

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Solution Overview

Problem

Current error correction methods in memory subsystems, particularly those using low-density parity check (LDPC) codes and staircase codes, are vulnerable to high reliability errors (HREs) and suffer from performance degradation due to the need to retrieve additional data for decoding, which is impractical for moderate to high error rates.

Innovation Solution

The implementation of syndrome-based decoders in memory devices that transmit encoded data along with syndromes to an error corrector, allowing for robust error correction without the need for additional data transfer, thereby improving performance and reducing data transmission while maintaining high correction capabilities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If syndrome-based decoders are implemented to improve error correction robustness, then error correction capability is improved, but device complexity increases

Engineering Contradiction:
Improveerror correction capabilityVSAvoiddecoder complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The error correction system is segmented into distinct functional components: syndrome computation unit that calculates syndromes from received data, syndrome storage unit that stores computed syndromes, and syndrome-based decoder that uses stored syndromes for error correction. This segmentation allows each component to be optimized independently while working together to achieve robust error correction.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Syndromes are computed and stored in advance before actual error correction is needed. The syndrome computation unit calculates syndromes from received encoded data and stores them in the syndrome storage unit, so that when error correction is required, the decoder can immediately access pre-computed syndromes without waiting for additional data retrieval or computation.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If additional data is retrieved for decoding to maintain error correction capability, then error correction robustness is improved, but data transmission volume increases

Engineering Contradiction:
Improveerror correction robustnessVSAvoiddata transmission volume
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The essential error correction information (syndromes) is extracted from the encoded data and transmitted separately. Instead of retrieving additional encoded data blocks for decoding, the system extracts and transmits only the syndrome values, which contain all necessary information for error correction. This extraction principle significantly reduces the amount of data that must be transmitted and stored.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The system changes the parameter representation of error correction information from transmitting full encoded data blocks to transmitting compressed syndrome values. Syndromes are mathematical parameters that encapsulate the essential error-detection and correction information in a compact form, reducing transmission volume while maintaining correction capability.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If traditional LDPC or staircase codes are used to maintain error correction capability, then correction robustness is improved, but performance degrades due to additional data retrieval requirements

Engineering Contradiction:
Improveerror correction capabilityVSAvoiddecoding performance
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

Syndromes serve as an intermediary between received encoded data and the error correction process. Instead of directly processing large volumes of encoded data or retrieving additional data blocks, the syndrome computation unit transforms the received data into compact syndrome parameters that mediate the error correction process, improving decoding performance by reducing computational complexity and data access requirements.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentUS12032444B2Error correction with syndrome computation in a memory device
Publication Date: 2024.07.09 MICRON TECHNOLOGY INC
  • US12032444B2 patent drawing
  • US12032444B2 patent drawing
  • US12032444B2 patent drawing

AI summary

Methods, systems, and apparatus for error correction with syndrome computation in a memory device are described. A first syndrome for first encoded data is generated in a memory device. The first syndrome and the first encoded data are transmitted to a controller that is coupled with the memory device. A second syndrome for first and second encoded data is generated. The first encoded data and the second encoded data are interrelated according to an error correction code. The second syndrome is transmitted to the controller without the second encoded data and the controller is to decode the first encoded data based on at least one of the first syndrome, the second syndrome, or a combination thereof.