Memory Controller Sudden Power-Off Recovery
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Sudden power-off events in memory devices can lead to incomplete program operations, resulting in incorrect data and increased memory block usage, which shortens the lifespan of memory devices due to frequent allocation of new blocks for recovery.
Innovation Solution
A memory controller with a dummy program controller, parity data controller, and valid data controller manages sudden power-off recovery by performing dummy programming operations, resetting and generating parity data, and moving valid data to maintain chipkill group units, thereby reducing memory block consumption and extending device lifespan.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a program operation is interrupted by sudden power-off, then data integrity is compromised, but allocating new memory blocks for recovery increases device wear and shortens lifespan
Solution Approach 1:
The patent performs preliminary actions by identifying and marking pages affected by sudden power-off before actual recovery operations. The dummy program controller proactively prepares the memory structure by determining which pages need dummy programming to maintain chipkill group integrity, preventing cascading failures and enabling efficient recovery without allocating new blocks.
Solution Approach 2:
The patent recovers discarded or corrupted data by performing dummy program operations on selected pages and moving valid data to new locations within existing blocks. The valid data controller identifies pages with valid data and relocates them to maintain logical continuity, effectively recovering usable space without requiring new block allocation.
2Productivity
If dummy program operations are performed to maintain chipkill group units, then recovery efficiency improves, but additional programming cycles increase memory block wear
Solution Approach 1:
The patent applies local quality by selectively performing dummy program operations only on specific pages that are part of chipkill groups affected by sudden power-off, rather than entire blocks. The dummy program controller precisely identifies which pages need intervention to maintain chipkill group integrity, minimizing unnecessary programming cycles and associated wear on unaffected memory regions.
Solution Approach 2:
The patent segments the memory recovery process into distinct operational phases: identifying affected pages, determining dummy program targets, executing dummy operations, and moving valid data. This segmentation allows the system to apply recovery operations at the page level within chipkill groups, reducing the scope of wear-inducing operations compared to block-level recovery.
3Ease of operation
If valid data is moved to maintain chipkill group units, then data accessibility is improved, but additional write operations increase energy consumption and wear
Solution Approach 1:
The valid data controller performs preliminary identification of pages containing valid data before initiating move operations. By pre-assessing which pages need relocation to maintain chipkill group integrity, the system avoids unnecessary data movement and associated energy consumption, executing transfers only when required for data accessibility.
Solution Approach 2:
The patent changes the physical location parameter of valid data within the memory structure, moving data between pages while maintaining logical accessibility. This parameter change enables the system to preserve data integrity and accessibility without requiring full block rewrites, reducing energy consumption compared to more extensive data relocation strategies.
Data Source
AI summary
A memory controller and a method of operating the same may provide recovery from a Sudden Power-Off (SPO). The memory controller may control a memory device including a plurality of memory blocks, each memory block having a plurality of pages. The memory controller may include a dummy program controller configured to, after an SPO has occurred while a program operation was being performed on a page of the memory device, control a dummy program operation for recovering from the SPO; a parity data controller configured to control resetting and generation of parity data for chipkill decoding based on pages on which the dummy program operation is determined to be performed; and a valid data controller configured to control movement of valid data based on a number of pages on which the dummy program operation is to be performed.