Read Lookahead L2P Caching for Sequential Memory Access
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Memory systems in automotive applications face inefficiencies due to limited memory capacity and low queue depth, leading to idle dies and increased latency during sequential read workflows.
Innovation Solution
Implementing a read lookahead mode that pre-loads L2P mapping information for sequential LBAs into a cache buffer, ensuring multiple dies are kept busy and reducing latency through improved parallel performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If read commands are processed sequentially without pre-loading, then memory access follows standard procedure, but dies become idle and latency increases during sequential read workflows
Solution Approach 1:
The patent implements read lookahead mode that pre-loads L2P mapping information for sequential LBAs into the cache buffer before actual read commands are executed. This preliminary action ensures that when sequential read commands arrive, the mapping information is already available in the cache, keeping dies busy and reducing access latency.
Solution Approach 2:
The patent maintains die utilization by continuously pre-loading mapping information for sequential LBAs. The counter tracks sequential read patterns and activates read lookahead mode to ensure dies remain occupied with useful work, eliminating idle periods and maintaining continuous productive operation.
2Quantity of substance
If memory capacity is limited, then device size is reduced, but queue depth becomes shallow and dies go idle
Solution Approach 1:
The patent pre-loads L2P mapping information into the cache buffer before it is needed, using available memory capacity efficiently. This allows the system to maintain shallow queue depth while still keeping dies busy, as the pre-loaded information is ready for immediate use without requiring additional memory capacity.
Solution Approach 2:
The patent introduces a cache buffer as an intermediary between the limited memory capacity and the dies. The cache buffer stores pre-loaded L2P mapping information, acting as a mediator that allows dies to remain occupied even when overall memory capacity and queue depth are limited.
3Speed
If read lookahead mode is activated, then parallel performance improves and latency reduces, but additional processing overhead is introduced
Solution Approach 1:
The patent activates read lookahead mode that performs preliminary loading of L2P mapping information for sequential LBAs. This pre-loading action improves memory access speed by having information ready in advance, while the counter-based activation mechanism keeps the additional processing complexity manageable by only enabling the feature when beneficial.
Data Source
AI summary
Methods, systems, and devices for read lookahead activation in a memory system are described. A memory system may activate a read lookahead mode, which may enable the memory system to pre-load, to a cache buffer, logical to physical (L2P) mapping information for logical block addresses (LBAs) of a read command that are sequential to an LBA indicated by previous a read command. In some examples, activation of the read lookahead mode may be in response to identification of a sequential read workload. For example, the memory system may increment a counter to determine that a quantity of read commands received are for sequential LBAs, thereby determining that the command sequence is sequential in nature. The memory system may utilize the pre-loaded L2P mapping information to perform commands received from a host system in accordance with a sequential read pattern.