Dynamic Garbage Collection Threshold for Memory Storage Devices

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Rewritable non-volatile memory devices frequently perform garbage collection operations due to a fixed threshold value, leading to decreased operation performance even when there is sufficient storage space, as the number of physical programming units increases without a corresponding increase in valid data.

Innovation Solution

A memory management method that dynamically adjusts a threshold value based on the valid data amount and the number of physical erasing units programmed in single-page mode, delaying the start of garbage collection and allowing for adaptive programming mode changes between single-page and multi-page modes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Extent of automation

If a fixed threshold value is used to determine when to perform garbage collection, then the memory storage device can automatically trigger garbage collection, but the frequency of garbage collection increases unnecessarily leading to reduced operation performance

Engineering Contradiction:

Improveautomatic garbage collection triggerVSAvoidoperation performance

Core Design Contradiction:

Extent of automationVSProductivity

Solution Approach 1:

The patent applies dynamics by changing the threshold value from fixed to dynamic. The threshold is now determined based on the valid data amount stored in physical erasing units, allowing the garbage collection trigger point to adapt to actual data usage conditions. This resolves the contradiction by enabling automatic garbage collection while preventing unnecessary frequent triggers that would reduce operation performance.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter used for garbage collection determination from a fixed threshold to a dynamic threshold based on valid data amount. By adjusting this parameter according to actual storage conditions, the system achieves both automation and optimal performance, avoiding the pitfall of excessive garbage collection frequency.

Inventive Principle:

Principle #35Parameter changes

2Quantity of substance

If the number of physical programming units increases due to continuous write operations, then more data can be stored, but the number of physical erasing units increases without corresponding valid data increase, causing frequent garbage collection

Engineering Contradiction:

Improvestorage capacity utilizationVSAvoidoperation performance

Core Design Contradiction:

Quantity of substanceVSProductivity

Solution Approach 1:

The patent implements feedback by continuously monitoring the valid data amount stored in physical erasing units and using this information to determine the threshold for garbage collection. This feedback mechanism allows the system to distinguish between actual storage needs and artificial inflation of physical programming unit counts, thereby maintaining high productivity while utilizing storage capacity effectively.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent replaces the mechanical counting of physical programming units with a more intelligent system that measures valid data amount. This substitution allows the system to ignore the quantity of physical units and focus on actual useful data stored, preventing false triggers of garbage collection and maintaining optimal operation performance.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If garbage collection is performed frequently to manage physical erasing units, then data validity is maintained, but the overall operation performance is influenced due to excessive collection frequency

Engineering Contradiction:

Improvedata validityVSAvoidoperation performance

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent changes the parameter for garbage collection determination from fixed to dynamic based on valid data amount. This ensures that garbage collection is performed only when actually needed to maintain data validity, rather than following a rigid schedule that would reduce operation performance. The dynamic threshold adapts to real storage conditions, balancing reliability and productivity.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent applies dynamics by making the garbage collection threshold adaptive rather than static. The threshold dynamically adjusts according to the valid data amount, allowing the system to maintain data validity through intelligent timing of garbage collection while avoiding excessive frequency that would harm operation performance.

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS10310739B2Memory management method, memory control circuit unit and memory storage device

Publication Date: 2019.06.04 PHISON ELECTRONICS

AI summary

A memory management method is provided according to an exemplary embodiment of the disclosure. The method includes: obtaining a valid data parameter based on a valid data amount of valid data stored in a plurality of physical erasing units, and obtaining a first threshold value based on the valid data parameter. The method also includes: obtaining a first determination parameter based on a number of a plurality of first physical erasing units, and the first physical erasing units are physical erasing units being programmed for storing data by using a single-page programming mode. The method further includes: performing a garbage collection operation if the first determination parameter is greater than the first threshold value.