Continuous Mapping Table for Flash Memory Access

Solution Overview

Problem

Existing memory storage devices using rewritable non-volatile memory modules face challenges in maintaining efficient data access speed due to the invalidation of continuous mapping tables when data is overwritten, leading to reduced performance in flash memory storage systems.

Innovation Solution

A method and device that establish a continuous mapping table to record the start logical address, length, and bitmap information for written data, allowing for quick and effective data access by marking virtual block bits as valid or invalid, enabling the selection of either a continuous mapping table or logical-physical address mapping table for reading data.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If a continuous mapping table is used to record mapping information for continuously written data, then data access speed is improved, but the mapping table becomes invalid when data is overwritten

Engineering Contradiction:

Improvedata access speedVSAvoidmapping table validity

Core Design Contradiction:

SpeedVSReliability

Solution Approach 1:

The patent segments the mapping information storage by dividing it into two types: continuous mapping tables for sequentially written data and logical-physical mapping tables for random access data. This segmentation allows each mapping table to be optimized for its specific use case, with continuous mapping tables providing fast access for sequential data while logical-physical mapping tables handle overwrites and random access scenarios.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent implements a dynamic mapping mechanism where the system automatically selects between continuous mapping tables and logical-physical mapping tables based on the access pattern. When data is accessed sequentially, the continuous mapping table is used for high-speed access; when data is overwritten or accessed randomly, the system dynamically switches to the logical-physical mapping table to maintain validity and accuracy.

Inventive Principle:

Principle #15Dynamics

2Reliability

If a logical-physical address mapping table is used to record all mapping relationships, then data access reliability is maintained, but access speed decreases due to larger table size and more data to process

Engineering Contradiction:

Improvemapping relationship accuracyVSAvoiddata access speed

Core Design Contradiction:

ReliabilityVSSpeed

Solution Approach 1:

The patent segments the mapping information storage by dividing it into two types: continuous mapping tables for sequentially written data and logical-physical mapping tables for random access data. This segmentation allows each mapping table to be optimized for its specific use case, with continuous mapping tables providing fast access for sequential data while logical-physical mapping tables handle overwrites and random access scenarios.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Instead of maintaining a complete logical-physical mapping table for all data, the patent uses partial mapping information stored in continuous mapping tables for sequentially written data. This partial action approach provides sufficient mapping information for fast access without the overhead of maintaining a complete mapping table, achieving speed improvement while maintaining reliability through selective use of mapping tables.

Inventive Principle:

Principle #16Partial or excessive action

3Quantity of substance

If mapping information is recorded with less amount of data, then random access memory space is saved, but the ability to handle data overwrites is reduced

Engineering Contradiction:

Improvememory space usageVSAvoidhandling data overwrites

Core Design Contradiction:

Quantity of substanceVSAdaptability or versatility

Solution Approach 1:

The patent segments the mapping information storage by dividing it into two types: continuous mapping tables for sequentially written data and logical-physical mapping tables for random access data. This segmentation allows each mapping table to be optimized for its specific use case, with continuous mapping tables providing fast access for sequential data while logical-physical mapping tables handle overwrites and random access scenarios.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent creates a universal mapping system that can handle both sequential access and random access scenarios, as well as data overwrites. The system uses continuous mapping tables for sequential data with compact storage, and logical-physical mapping tables for random access and overwrite scenarios, providing multi-functionality across different access patterns while optimizing memory space usage for each case.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS11748026B2Mapping information recording method, memory control circuit unit, and memory storage device

Publication Date: 2023.09.05 HEFEI CORE STORAGE ELECTRONICS LTD

AI summary

A mapping information recording method for a rewritable non-volatile memory module is provided. The rewritable non-volatile memory module includes multiple physical erasing units, and each of the physical erasing unit includes multiple physical programming units. The mapping information recording method includes: receiving first continuous data from a host system, wherein the host system instructs to store the first continuous data to a first continuous logical address; establishing a continuous mapping table to record a start logical address of the first continuous logical address, a length of the first continuous logical address, and a bitmap; writing the first continuous data into first physical programming units; and marking bits of virtual blocks corresponding to the first continuous logical address in the bitmap as a valid state, numbering the virtual blocks, and recording the numbers into the continuous mapping table.