Adaptive Read Retry Flow for Solid State Memory

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Solid-state storage systems face performance issues due to read retries necessitated by errors in data retrieval from memory cells, which can lead to increased latency and error rates, particularly as the number of errors increases, making successful data reconstruction by ECC algorithms impossible.

Innovation Solution

The implementation of adaptive decoding parameters, including different read thresholds and decoding algorithms, for repeated read operations to improve data retrieval success, with specific parameters optimized based on retention time, P/E cycle value, and page number to minimize bit error rates.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If read retry operations are performed with default decoding parameters, then data retrieval can be attempted multiple times, but the error rate increases and read performance deteriorates due to repeated failed attempts

Engineering Contradiction:

Improvedata retrieval success rateVSAvoidread performance

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent implements dynamic adjustment of decoding parameters (such as read thresholds and voltage levels) based on the retry count. Each retry operation uses different parameters than the previous attempt, allowing the system to adapt to varying error conditions and improve success rate without permanently degrading read performance

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system changes physical parameters (voltage thresholds, decoding algorithm settings) between retry attempts. By modifying these parameters systematically based on retry history, the system can overcome errors that prevented successful reads with default parameters, thereby improving reliability while controlling performance impact

Inventive Principle:

Principle #35Parameter changes

2Productivity

If adaptive decoding parameters are used for retry operations, then data retrieval efficiency improves, but system complexity increases due to parameter management requirements

Engineering Contradiction:

Improvedata retrieval efficiencyVSAvoidparameter management complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent pre-establishes multiple sets of decoding parameters and their corresponding usage conditions before actual read operations begin. This preliminary preparation allows the system to quickly select appropriate parameters during retry operations without complex real-time calculations, reducing operational complexity while maintaining improved retrieval efficiency

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system automatically selects and applies appropriate decoding parameters based on retry count and error patterns without requiring external intervention or complex manual configuration. The parameter management system serves itself by using performance data to automatically optimize parameter selection, reducing the burden on system operators

Inventive Principle:

Principle #25Self-service

Data Source

PatentUS10236054B1Method and system for systematic read retry flow in solid state memory using a retry table

Publication Date: 2019.03.19 EMC IP HLDG CO LLC

AI summary

In general, embodiments of the technology relate to improving read performance of solid-state storage by using decoding parameters deemed particularly suitable for the read operation that is currently being performed. More specifically, embodiments of the technology relate to using different decoding parameters when a read operation needs to be repeated because the initial read operation has failed.