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Author Chen, Yiran ♦ Wong, Weng-Fai ♦ Li, Hai ♦ Koh, Cheng-Kok ♦ Zhang, Yaojun ♦ Wen, Wujie
Source ACM Digital Library
Content type Text
Publisher Association for Computing Machinery (ACM)
File Format PDF
Copyright Year ©2013
Language English
Subject Domain (in DDC) Computer science, information & general works ♦ Data processing & computer science
Subject Keyword MLC ♦ STT-RAM ♦ Spintronic ♦ Cache ♦ Memories
Abstract It has been predicted that a processor's caches could occupy as much as 90% of chip area a few technology nodes from the current ones. In this article, we investigate the use of multilevel spin-transfer torque RAM (STT-RAM) cells in the design of processor caches. We start with examining the access (read and write) scheme for multilevel cell (MLC) STT-RAM from a circuit design perspective, detailing the read and write circuits. Compared to traditional SRAM caches, a multilevel cell (MLC) STT-RAM cache design is denser, fast, and requires less energy. However, a number of critical architecture-level issues remain to be solved before MLC STT-RAM technology can be deployed in processor caches. We shall offer solutions to the issue of bit encoding as well as tackle the write endurance problem. In particular, the latter has been neglected in previous works on STT-RAM caches. We propose a set remapping scheme that can potentially prolong the lifetime of a MLC STT-RAM cache by 80× on average. Furthermore, a method for recovering the performance that may be lost in some applications due to set remapping is proposed. The impacts of process variations of the MLC STT-RAM cell on the robustness of the memory hierarchy is also discussed, together with various enhancement techniques, namely, ECC and design redundancy.
ISSN 15504832
Age Range 18 to 22 years ♦ above 22 year
Educational Use Research
Education Level UG and PG
Learning Resource Type Article
Publisher Date 2013-05-01
Publisher Place New York
e-ISSN 15504840
Journal ACM Journal on Emerging Technologies in Computing Systems (JETC)
Volume Number 9
Issue Number 2
Page Count 22
Starting Page 1
Ending Page 22


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Source: ACM Digital Library