Hashing-Based Error Classification for Memory Reliability

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Solution Overview

Problem

Computer memory systems face challenges in efficiently detecting and distinguishing between random and repeat single-bit errors in DIMMs, which can lead to premature flagging of healthy modules and failure to identify serious errors, due to increasing bit error rates and tighter timing requirements.

Innovation Solution

A method and system that utilize error detection control logic to count random and repeat errors, with a hashing process to log errors at a block level, and generate alerts when thresholds are reached, allowing for predictive failure analysis and distinguishing between random and repeat errors to prevent unnecessary module flagging.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a single threshold is used for all single-bit errors, then the alert generation is simple, but healthy memory modules are prematurely flagged while serious errors are missed

Engineering Contradiction:
Improvememory system reliabilityVSAvoiderror detection system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent segments errors into two distinct categories: random errors and repeat errors. This segmentation allows the system to apply different thresholds and analysis methods to each error type, improving reliability by distinguishing between transient noise-induced errors and systematic failures, while managing complexity through structured classification rather than overwhelming complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements preliminary action by logging error locations and characteristics before final alert generation. The system maintains error logs, performs hashing operations, and pre-classifies errors as random or repeat before reaching the alert threshold. This preliminary processing enables more accurate reliability assessment without proportionally increasing complexity at the alert generation stage.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If all single-bit errors are treated equally, then the detection process is simple, but the system cannot distinguish between transient noise errors and systematic failures

Engineering Contradiction:
Improveerror classification precisionVSAvoiderror tracking system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent divides the error detection space into distinct segments: random errors (transient, noise-induced) and repeat errors (systematic, potential hardware failures). This segmentation achieves precise error classification by capturing the essential difference between error types, while managing complexity through a structured two-category system rather than attempting to identify every possible error cause.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system performs preliminary error logging and classification before final analysis. By maintaining error logs that record location, timestamp, and type information, and by pre-computing hash values for error locations, the system prepares data in advance for accurate classification. This preliminary action enables precise measurement of error characteristics without proportionally increasing complexity during the critical alert generation phase.

Inventive Principle:
Principle #10Preliminary action

3Productivity

If the system flags all errors above a threshold, then alert generation is straightforward, but unnecessary alerts are generated for random errors

Engineering Contradiction:
Improvealert generation efficiencyVSAvoidalert accuracy
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent segments the alert generation process into two parallel tracks: one for random errors with a higher threshold and one for repeat errors with a lower threshold. This segmentation improves alert accuracy by matching threshold sensitivity to error severity, while maintaining productivity through parallel processing of both error types rather than sequential analysis.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system performs preliminary classification of errors as random or repeat before applying threshold comparisons. By pre-processing error data to determine error type and maintaining separate counters for each category, the system prepares the groundwork for accurate threshold evaluation. This preliminary action enables efficient alert generation with high accuracy, as the classification work is done before the critical threshold comparison stage.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentUS8347154B2Use of hashing function to distinguish random and repeat errors in a memory system
Publication Date: 2013.01.01 LENOVO GLOBAL TECHNOLOGIES SWITZERLAND INTERNATIONAL GMBH
  • US8347154B2 patent drawing
  • US8347154B2 patent drawing
  • US8347154B2 patent drawing

AI summary

One embodiment provides an error detection method wherein single-bit errors in a memory module are detected and identified as being a random error or a repeat error. Each identified random error and each identified repeat error occurring in a time interval is counted. An alert is generated in response to a number of identified random errors reaching a random-error threshold or a number of identified repeat errors reaching a repeat-error threshold during the predefined interval. The repeat-error threshold is set lower than the random-error threshold. A hashing process may be applied to the memory address of each detected error to map the location of the error in the memory system to a corresponding location in an electronic table.