Memory Controller L2P Mapping for O(1) SSD Data Search
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing data search algorithms in SSDs with volatile memory, such as DRAM, suffer from high time complexity, particularly for frequently accessed 'hot data, which can become a performance bottleneck when data quantity is large.
Innovation Solution
Implementing an expanded L2P mapping table that maps logical addresses to both volatile and non-volatile memory, reducing search complexity to O(1) by using dedicated circuits for parallel data search across both memory types.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If traditional data search algorithms are used in SSDs with volatile memory, then the system can handle large amounts of data, but the time complexity becomes high especially for frequently accessed hot data
Solution Approach 1:
The L2P mapping table is segmented into multiple segments, each stored in a separate volatile memory bank. This segmentation allows parallel search operations across multiple memory banks simultaneously, reducing the overall search time complexity from O(n) to O(1) for hot data while maintaining the ability to handle large data quantities.
Solution Approach 2:
The patent introduces a new dimension to the L2P mapping structure by organizing it as a multi-dimensional array with segment dimensions. This allows the search operation to access mapping information through multiple indexing dimensions (segment index, offset index), enabling constant-time access to mapping tables regardless of the total data quantity stored in the SSD.
2Loss of time
If an expanded L2P mapping table is implemented to map logical addresses to both volatile and non-volatile memory, then search complexity is reduced to O(1), but the device complexity increases
Solution Approach 1:
The L2P mapping table is divided into multiple segments stored in different volatile memory banks, with each segment containing a portion of the mapping information. This segmentation reduces the complexity of individual memory access operations while enabling parallel processing, achieving O(1) search complexity through structured division rather than monolithic table management.
Solution Approach 2:
The patent introduces segment index registers and offset index registers as intermediary structures between the logical address input and the volatile memory banks. These intermediaries simplify the complex mapping lookup process by breaking it into manageable steps: first determining the segment, then finding the specific entry within that segment, reducing the overall device complexity through structured intermediate processing.
Data Source
Figure 1
Figure 2A~2B
Figure 3
AI summary
In certain aspects, a memory system includes a volatile memory device and a memory controller operatively coupled to the volatile memory device. The volatile memory device is configured to store a logical-to-physical (L2P) mapping table. The memory controller is configured to maintain the L2P mapping table stored in the volatile memory device, such that the L2P mapping table maps a first set of logical addresses to identifiers (IDs) of memory blocks of a cache, respectively.