Memory Read Error Correction With Adaptive BCH Bit Flipping

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Solution Overview

Problem

Memory systems face complexity and performance deterioration issues due to repetitive error correction operations, which affect the efficiency and stability of data processing in portable electronic devices.

Innovation Solution

A memory system and operating method that perform bit flipping operations during repetitive error correction using the BCH decoding scheme, varying the number of flip bits for constituent codes, and gradually increasing the number of flip bits in the least reliable code until successful correction, while holding or adjusting flip bits in other codes based on error correction outcomes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If repetitive error correction operations are performed using traditional decoding schemes, then error correction capability is improved, but decoding latency increases and performance deteriorates

Engineering Contradiction:
Improveerror correction capabilityVSAvoiddecoding latency
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent applies dynamics by making the bit flipping operation adaptive rather than static. The controller dynamically adjusts the number of bit flipping operations based on the reliability status of each constituent code, performing more flips on less reliable codes and fewer or no flips on more reliable codes. This dynamic adaptation resolves the contradiction by optimizing error correction effort where needed while avoiding unnecessary operations elsewhere, thereby reducing overall decoding latency while maintaining error correction capability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of bit flipping count from a fixed value to a variable that depends on code reliability. By monitoring the reliability status of each constituent code and adjusting the number of bit flipping operations accordingly, the system achieves better error correction performance on unreliable codes while minimizing operations on reliable codes. This parameter change resolves the contradiction between thorough error correction and reduced decoding latency.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If traditional error correction methods are used, then error handling is improved, but system complexity increases

Engineering Contradiction:
Improveerror handling capabilityVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies local quality by treating different constituent codes differently based on their individual reliability characteristics. Rather than applying a uniform error correction approach to all codes, the system identifies least reliable constituent codes and applies bit flipping operations selectively to those specific codes. This localized approach improves error handling where needed while avoiding unnecessary complexity in processing reliable codes, thus resolving the contradiction between error handling capability and system complexity.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent segments the error correction process by dividing constituent codes into different reliability groups. The controller identifies and separates least reliable constituent codes from more reliable ones, applying different bit flipping strategies to each segment. This segmentation allows the system to focus computational resources on problematic areas while simplifying processing for reliable segments, thereby reducing overall system complexity while maintaining robust error handling.

Inventive Principle:
Principle #1Segmentation

3Ease of operation

If fixed number of bit flipping operations is performed in each loop, then processing simplicity is improved, but error correction effectiveness deteriorates

Engineering Contradiction:
Improveprocessing simplicityVSAvoiderror correction effectiveness
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent transforms the static bit flipping count into a dynamic parameter that adapts to code reliability. Instead of performing a fixed number of bit flipping operations on all codes, the system adjusts the flipping count based on each code's reliability status. This dynamic approach maintains processing simplicity through automated reliability assessment while dramatically improving error correction effectiveness by concentrating flips where they are most needed.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements feedback by using reliability status information from decoding results to guide subsequent bit flipping operations. The controller monitors the performance of each constituent code and uses this feedback to adjust the number of bit flipping operations in subsequent loops. This feedback mechanism ensures that error correction effectiveness is improved without significantly complicating the processing, as the adjustments are based on clear reliability metrics.

Inventive Principle:
Principle #23Feedback

Data Source

PatentUS10496476B2Memory system and operating method thereof
Publication Date: 2019.12.03 SK HYNIX INC
  • US10496476B2 patent drawing
  • US10496476B2 patent drawing
  • US10496476B2 patent drawing

AI summary

A memory system may include: a memory device including a plurality of pages for storing data and a plurality of memory blocks including the pages; and a controller configured to read data, which corresponds to a read command received from a host, from the pages, perform bit flipping with respect to a plurality of constituent codes for the read data, and perform an error correction operation, the bit flipping is updated corresponding to a number of error correction bits in the constituent codes.