Descriptor Cache for Flash Memory Address Mapping
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In data storage devices, particularly those using flash memory, the inability to perform overwrite or in-place updates necessitates efficient address mapping techniques to maintain performance, as new address mapping information must be added and retrieved quickly to handle host device requests effectively.
Innovation Solution
A data storage device with a controller that includes an address translator generating map data with physical addresses and meta data, a descriptor cache manager for continuous storage of meta data, and a map cache manager for storing and searching map data using head and tail pointers to optimize address mapping and retrieval.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If address mapping information is stored in a traditional cache structure with scattered meta data, then retrieval speed may be maintained, but storage space is wasted due to empty spaces between meta data and device complexity increases
Solution Approach 1:
The patent combines multiple scattered meta data entries into a single continuous storage area called a descriptor cache. Instead of having meta data dispersed throughout the cache with empty spaces between them, all meta data are stored contiguously in one location, eliminating wasted space and simplifying the cache structure while maintaining fast retrieval through the continuous organization.
2Reliability
If meta data is stored in a scattered manner in the cache, then address mapping can be maintained, but storage efficiency decreases due to empty spaces between meta data
Solution Approach 1:
The patent merges all meta data into a single continuous storage region in the descriptor cache. This consolidation eliminates the empty spaces that would exist between scattered meta data entries, thereby maximizing storage space utilization while preserving complete and accurate address mapping information for all cache lines.
Solution Approach 2:
The patent introduces a new organizational dimension by creating a separate, dedicated descriptor cache region that is distinct from the main data cache. This dimensional separation allows meta data to be stored continuously in a specialized area, improving both storage efficiency and the reliability of address mapping without interfering with the main cache operations.
3Ease of manufacture
If traditional cache management is used without continuous meta data storage, then implementation is simpler, but performance is reduced due to inefficient address mapping operations
Solution Approach 1:
The patent segments the cache into two distinct functional parts: a descriptor cache for storing meta data and a data cache for storing actual data. This segmentation allows each part to be optimized for its specific purpose, with the descriptor cache providing efficient address mapping information and the data cache providing fast data access, thereby improving overall data processing speed while maintaining clear implementation boundaries.
Data Source
AI summary
A data storage device may include a storage; and a controller, wherein the controller comprises: an address translator configured to generate multiple map data, each including a physical address of the storage corresponding to a logical address and multiple meta data for the multiple map data respectively; a descriptor cache manager configured to add new meta data to a storage area of a descriptor cache, the storage area for the new meta data being physically continuous with a storage area in which last meta data, of the multiple meta data, is stored and assign a head pointer and a tail pointer to select positions in the descriptor cache; a map cache manager configured to store the multiple map data in a map cache; and a map search component configured to search the descriptor cache according to a search range determined by the head pointer and the tail pointer.