4M：一种基于非易失性存储器的新型混合存储体系
4M: A Hybrid Storage System Based on Nonvolatile Memory
摘要
NAND闪存以其耐冲击性、非易失性和低能耗等优越性，被越来越广泛的应用于嵌入式设备中。同传统的SLC NAND闪存相比，新型TLC NAND闪存具有更高的密度和更低的成本；然而TLC闪存读取/写入延迟高、使用耐久性低，成为其使用瓶颈。另一方面，传统基于闪存的嵌入式系统中，闪存信息映射保存在内存中，每当系统断电重启后都需要遍历闪存文件系统然后重建映射表，随着闪存容量迅速增大，闪存映射表占用内存空间也急剧增大且并且重建十分耗时。与DRAM相比，新型非易失性存储器PCM（Phase Change Memory，相变存储器）在非易失性和功耗方面具有明显的优势，并且性能与DRAM相近。为此，本文提出了一个基于非易失性存储器的混合存储体系架构设计，名为4M（DRAM，PCM，SLC NAND flash memory，TLC NAND flash memory）：系统内存使用DRAM/PCM混合内存，外存使用TLC/SLC混合闪存；闪存信息表保存在PCM中；数据依据访问频率分别保存在SLC闪存和TLC闪存中。实验结果表明本文提出的4M架构可以有效提高系统性能。
Abstract
With shock resisting, nonvolatile and low power consuming characteristics, NAND flash memories are used widely as storage devices for various embedded systems. In particular, tripe-level cell (TLC) flash memory provides much higher density and lower cost than single-level cell (SLC) and multilevel cell (MLC) flash memory. However, TLC flash memory also suffers from longer read/write latency and much lower endurance compared to its counterpart. As the mapping table is usually cached in dynamic random access memory (DRAM), its volatile nature requires the recovery routine rebuild the mapping table. A full scan of the flash memory chip is usually needed when the system restarts, which is time consuming. Recent advances in phase change memory (PCM) provide new opportunities to replace DRAM in memory systems due to its superior scalability, non-volatility, lower leakage power and close-to-DRAM performance. With these features, it is promising to overcome the problems of DRAM by storing the FTL mapping table in PCM. Therefore, we propose a hybrid storage system architecture based on a nonvolatile memory, called 4M (DRAM, PCM, SLC NAND flash memory, TLC NAND flash memory).In 4M, system memory adopts DRAM + PCM hybrid memory, and external memory adopts TLC/SLC hybrid flash memory; besides, FTLtable is stored in the PCM;in terms of access frequency, data are stored in SLC or TLC flash memory. We conduct trace-driven experiments, and the resuts show our proposed design can effecitvely improve system performance.关键词
PCM/NAND闪存/TLC/SLCKey words
PCM/NAND flash memory/TLC/SLC引用本文复制引用
姚雷,刘铎.4M：一种基于非易失性存储器的新型混合存储体系[EB/OL].(2017-05-16)[2026-04-02].http://www.paper.edu.cn/releasepaper/content/201705-1018.学科分类
微电子学、集成电路/电子元件、电子组件/计算技术、计算机技术
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