Non-Volatile Memory Cache with Fixed Region for Power Interruption

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional storage apparatuses using non-volatile memory as a cache face challenges in efficiently managing fixed and non-fixed regions, protecting data against power interruptions, and extending the lifespan of non-volatile memory due to wear level issues, with existing solutions failing to address these concerns effectively.

Innovation Solution

A storage apparatus using non-volatile memory as a cache, where the memory is divided into fixed and non-fixed regions based on data permanence, with a block management unit allocating physical blocks using virtual addresses to manage wear levels and facilitate recovery from power interruptions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by stationary object

If non-volatile memory is used as cache to reduce power consumption by interrupting power supply to main storage medium, then power consumption is reduced, but data management complexity increases due to fixed and non-fixed regions

Engineering Contradiction:

Improvepower consumptionVSAvoiddata management complexity

Core Design Contradiction:

Use of energy by stationary objectVSDevice complexity

Solution Approach 1:

The non-volatile memory is divided into a fixed region for storing data that should be retained even when power is interrupted, and a non-fixed region for temporary caching. This segmentation allows the system to reduce power consumption by interrupting power to the main storage medium while maintaining data integrity through the fixed region, and managing cache operations through the non-fixed region.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A block management unit is introduced as an intermediary component that manages physical blocks allocated to the non-volatile memory using virtual addresses. This mediator handles the complexity of managing fixed and non-fixed regions, wear level distribution, and power interruption recovery, thereby reducing the apparent complexity for the host system.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Use of energy by stationary object

If non-volatile memory is used as cache to enable power interruption, then power consumption is reduced, but reliability decreases due to potential data loss from unexpected power interruption

Engineering Contradiction:

Improvepower consumptionVSAvoiddata protection reliability

Core Design Contradiction:

Use of energy by stationary objectVSReliability

Solution Approach 1:

The fixed region is prepared in advance to store data that must be protected against power interruptions. The block management unit maintains wear level information and block allocation status in the fixed region before power interruption occurs, enabling recovery of this information after power is restored without risking data loss.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system provides beforehand protection by maintaining a fixed region that preserves critical data and management information even when power is interrupted. This cushioning mechanism ensures that unexpected power interruptions do not result in data loss, as the fixed region retains data without requiring continuous power supply.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

3Productivity

If non-volatile memory blocks are frequently accessed for caching operations, then access efficiency is improved, but memory lifespan decreases due to wear level accumulation

Engineering Contradiction:

Improveaccess efficiencyVSAvoidmemory lifespan

Core Design Contradiction:

ProductivityVSDuration of action of stationary object

Solution Approach 1:

The block management unit tracks wear levels of physical blocks and dynamically changes the mapping between virtual addresses and physical blocks. When a block reaches a certain wear threshold, the system changes its parameter status by marking it as worn and reallocating virtual addresses to different physical blocks, thereby distributing wear evenly and extending memory lifespan while maintaining access efficiency.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The system discards worn-out blocks from active use and recovers them by reallocation after wear leveling. The block management unit identifies blocks with high wear levels, stops using them for new data, and redistributes data to less worn blocks. This process allows the memory system to extend its overall lifespan by continuously recovering capacity from worn blocks through redistribution.

Inventive Principle:

Principle #34Discarding and recovering

Data Source

PatentUS7774541B2Storage apparatus using non-volatile memory as cache and method of managing the same

Publication Date: 2010.08.10 SAMSUNG ELECTRONICS CO LTD

AI summary

A storage apparatus using a non-volatile memory, which retains data even after power interruption, as its cache and a method of managing the same are provided. The storage apparatus includes a main storage medium, a non-volatile memory used as a cache of the main storage medium, a region of the non-volatile memory being divided into a fixed region and a non-fixed region according to whether or not data is fixed, and a block management unit managing physical blocks by means of virtual addresses, the physical blocks being allocated to the non-volatile memory.