Sub-block Accessible PCM Cache for NAND Data Preservation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional computing systems face inefficiencies in data retrieval and storage due to the volatility of cache memory, leading to data loss during power down and slower access times, especially when using NAND-based devices.
Innovation Solution
Implementing a non-volatile phase-change memory (PCM) as a cache for NAND devices, which allows frequently used NAND pages to be duplicated and stored in PCM, enabling faster access and preserving data during power cycles, with sub-block accessible addressing for finer control and improved memory utilization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If volatile cache memory is used to store frequently accessed data, then data retrieval speed is improved, but data loss occurs during power down
Solution Approach 1:
The memory system is segmented into two distinct parts: a volatile cache memory portion for fast data retrieval and a nonvolatile memory portion for data preservation. This segmentation allows each part to fulfill its specific function optimally while working together as an integrated system, resolving the contradiction between speed and reliability.
Solution Approach 2:
The volatile cache memory acts as an intermediary between the processor and the nonvolatile memory. Frequently accessed data is cached in the volatile portion for rapid access, while the nonvolatile portion ensures data persistence. This intermediary structure enables the system to achieve both fast retrieval speeds and data preservation during power cycles.
2Quantity of substance
If NAND-based memory devices are used for storage, then data capacity is improved, but access times increase
Solution Approach 1:
The memory system segments storage capacity and access function into separate components. The nonvolatile NAND-based portion provides large data capacity, while the volatile cache portion provides fast access times for frequently used data. This segmentation resolves the trade-off between capacity and access speed.
Solution Approach 2:
Different portions of the memory system have different local qualities optimized for specific functions. The volatile cache portion is optimized for speed with small capacity, while the nonvolatile portion is optimized for capacity with slower access. This local quality differentiation allows the overall system to achieve both large capacity and fast access times.
3Device complexity
If block-based memory access is used, then memory structure simplicity is improved, but access flexibility deteriorates
Solution Approach 1:
The memory system segments access operations into block-based access for the nonvolatile portion and byte-wise access for the volatile cache portion. This segmentation allows the system to maintain simple block-based structures where needed while providing flexible byte-level access where required, resolving the contradiction between structural simplicity and access flexibility.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution enhances data retrieval speed, reduces data loss during power cycles, and optimizes memory usage by allowing non-sequential access and efficient caching of frequently accessed data, improving overall system performance.
Implementation Method 1
non-volatile phase-change memory (PCM)
Data Source
AI summary
Subject matter disclosed herein relates to sub-block accessible cache memory.