新型非易失性存储器架构的缓存优化方法综述

Cache Optimization Approaches of Emerging Non-Volatile Memory Architecture:A Survey

随着半导体工艺的发展,处理器集成的片上缓存越来越大,传统存储器件的漏电功耗问题日益严峻,如何设计高能效的片上存储架构已成为重要挑战.为解决这些问题,国内外研究者讨论了大量的新型非易失性存储技术,它们具有非易失性、低功耗和高存储密度等优良特性.为探索spintransfer torque RAM(STT-RAM),phase change memory(PCM),resistive RAM(RRAM)和domainwall memory(DWM)四种新型非易失性存储器(non-volatile memory,NVM)架构缓存的方法,对比了其与传统存储器件的物理特性,讨论了其架构缓存的优缺点和适用性,重点分类并总结了其架构缓存的优化方法和策略,分析了其中针对新型非易失性存储器写功耗高、写寿命有限和写延迟长等缺点所作出的关键优化技术,最后探讨了新型非易失性存储器件在未来缓存优化中可能的研究方向.

With the development of semiconductor technology and CMOS scaling, the size of on-chip cache memory is gradually increasing in modern processor design. The density of traditional static RAM （SRAM） has been close to the limit. Moreover, SRAM consumes a large amount of leakage power which severely affects system performance. Therefore, how to design efficient on-chip storage architecture has become more and more challenging. To address these issues, researchers have discussed a large number of emerging non-volatile memory （NVM） technologies which have shown attractive features, such as non-volatile, low leakage power and high density. In order to explore cache optimization approaches based on emerging non-volatile memory including spin-transfer torque RAM （STT-RAM）, phase change memory （PCM）, resistive RAM （RRAM） and domain-wall memory （DWM）, this paper surveys the property of non-volatile memory compared with traditional memory devices. Then, the advantages, disadvantages and feasibility of architecting caches are discussed. To highlight their differences and similarities, a detailed analysis is then conducted to classify and summarize the cache optimization approaches and polieies. These key technologies are trying to solve the high write power, limited write endurance and long write latency of emerging non- volatile memory. Finally, the potential research prospect of emerging non-volatile memory in future storage architecture is discussed. Zhang Jun, born in 1978. PhD candidate and associate professor. Member of China Computer Federation.