Storage Controller Mode Switching for Long-Term Data Retention

Solution Overview

Problem

Non-volatile memory cells experience threshold voltage changes due to deterioration, leading to read errors in stored data, especially for long-term storage.

Innovation Solution

A storage device with a storage controller that switches between operation modes based on data retention times, programming data in memory regions with longer retention times for long-term storage to prevent read errors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If data is programmed in memory cells with shorter data retention time (second memory region), then programming speed and capacity are improved, but read errors occur after long-term storage due to threshold voltage changes

Engineering Contradiction:

Improveprogramming speedVSAvoiddata retention

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The non-volatile memory is divided into two distinct memory regions: a first memory region with long data retention time and a second memory region with short data retention time. This segmentation allows the system to selectively program data into appropriate regions based on required retention duration, resolving the contradiction between fast programming and long-term reliability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The storage controller dynamically selects the target memory region based on the data retention requirement. When long-term storage is needed, data is programmed into the first memory region; when short-term storage suffices, the second memory region is used. This dynamic adaptation optimizes both programming efficiency and data retention reliability.

Inventive Principle:

Principle #15Dynamics

2Reliability

If data is programmed in memory cells with longer data retention time (first memory region), then data integrity over time is improved, but programming speed and capacity are reduced

Engineering Contradiction:

Improvedata retentionVSAvoidprogramming speed

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The non-volatile memory is divided into two distinct memory regions: a first memory region with long data retention time and a second memory region with short data retention time. This segmentation allows the system to selectively program data into appropriate regions based on required retention duration, resolving the contradiction between fast programming and long-term reliability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The storage controller dynamically selects the target memory region based on the data retention requirement. When long-term storage is needed, data is programmed into the first memory region; when short-term storage suffices, the second memory region is used. This dynamic adaptation optimizes both programming efficiency and data retention reliability.

Inventive Principle:

Principle #15Dynamics

3Reliability

If the storage device always uses memory cells with longer retention time, then read errors are prevented, but memory capacity and programming efficiency are reduced

Engineering Contradiction:

Improveread error preventionVSAvoidmemory capacity

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The non-volatile memory is divided into two distinct memory regions: a first memory region with long data retention time and a second memory region with short data retention time. This segmentation allows the system to selectively program data into appropriate regions based on required retention duration, resolving the contradiction between fast programming and long-term reliability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The system changes the operational parameter (data retention time) by selecting different memory regions based on the specific data storage requirements. This parameter adaptation allows optimal use of memory capacity while maintaining sufficient reliability for each use case.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS12585410B2Storage device and operating method thereof

Publication Date: 2026.03.24 SAMSUNG ELECTRONICS CO LTD

AI summary

A storage device includes a storage controller and a non-volatile memory including a first memory region including first memory cells having a first data retention time and a second memory region including second memory cells having a second data retention time that is shorter than the first data retention time. Based on an erase request being received from a host in a first operation mode, the storage controller determines whether to switch from the first operation mode to a second operation mode. The storage controller programs program data in a memory region selected from the first memory region and the second memory region in the first operation mode, and the storage controller programs the program data in only the first memory region in the second operation mode.