Redundant FTL Table Architecture for Corruption-Tolerant Memory

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Solution Overview

Problem

Corruption of a single flash translation layer (FTL) table in memory sub-systems leads to errors and reduces the usability of the memory sub-system, often requiring it to be placed in a write-protect mode, which limits its functionality.

Innovation Solution

Implementing multiple FTL tables within the memory sub-system, allowing for redundancy by using a secondary FTL table if the primary one becomes corrupted, ensuring continued read-write access and improving reliability without the need for additional storage components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a single FTL table is used for address translation, then the device complexity is reduced and cost is lowered, but the reliability deteriorates because corruption of the single table causes errors and write-protect mode

Engineering Contradiction:

ImproveFTL table reliabilityVSAvoidFTL table structure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements multiple FTL tables (first FTL table and second FTL table) as copies of each other, storing the same logical-to-physical address mapping data. This allows the system to use a secondary copy if the primary table becomes corrupted, thereby improving reliability without significantly increasing complexity since the tables are redundant copies rather than independent structures

Inventive Principle:

Principle #26Copying

Solution Approach 2:

The patent prepares a second FTL table in advance as a backup before the first table becomes corrupted. This beforehand cushioning ensures that when corruption occurs, the system can immediately switch to the pre-prepared second table without entering write-protect mode, thus maintaining reliability while keeping the overall structure relatively simple

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

2Reliability

If multiple FTL tables are implemented for redundancy, then the reliability is improved by enabling continued operation after corruption, but the device complexity and cost increase

Engineering Contradiction:

Improvememory sub-system reliabilityVSAvoidFTL table management complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the functionality of multiple FTL tables into a unified address translation system where both tables work together under a single management framework. The controller manages both tables and can switch between them, combining their protective functions while maintaining a relatively simple overall structure that doesn't require separate management systems for each table

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent implements a second FTL table that stores the same data as the first table, which could be considered excessive redundancy. However, this partial redundancy (having just one backup table rather than multiple) provides sufficient reliability improvement while limiting the increase in complexity, achieving a balance between reliability and structural simplicity

Inventive Principle:

Principle #16Partial or excessive action

3Loss of information

If a single FTL table is used, then the storage capacity for data is maximized, but the loss of information increases when corruption occurs

Engineering Contradiction:

Improveaddress mapping information lossVSAvoidmemory capacity for data storage

Core Design Contradiction:

Loss of informationVSQuantity of substance

Solution Approach 1:

By creating a copy of the FTL table data in a second table, the patent ensures that address mapping information is preserved even if the first table becomes corrupted. This copying approach minimizes information loss while using existing memory components rather than requiring additional storage capacity

Inventive Principle:

Principle #26Copying

4Reliability

If additional storage components are added for redundant FTL data, then the reliability is improved, but the device complexity and cost increase

Engineering Contradiction:

ImproveFTL table redundancy reliabilityVSAvoidstorage component complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent makes the existing memory components universal by using them for both data storage and FTL table storage. The same memory array serves dual purposes: storing user data and storing redundant FTL table copies, thereby improving reliability through redundancy without adding separate storage components or increasing device complexity

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS12572469B2Independent flash translation layer tables for memory

Publication Date: 2026.03.10 MICRON TECHNOLOGY INC

AI summary

A memory sub-system with multiple flash translation layer (FTL) tables is disclosed. A host system can utilize a memory sub-system that includes one or more memory components. The host system can provide data to be stored at the memory sub-system and can request data to be retrieved from the memory sub-system. The FTL provides several services, including translating logical addresses used by the host to physical addresses used to access physical memory. If one FTL table is corrupted, the logical-to-physical mapping of another FTL table may be used, allowing the device to continue to provide read-write access to at least a portion of the memory sub-system. Thus, by use of a secondary FTL table, the reliability of the memory sub-system is improved.