@article{63b91bce5f3e49f788d13898014928b7,
title = "Write energy reduction for PCM via pumping efficiency improvement",
abstract = "The emerging Phase Change Memory (PCM) is considered to be a promising candidate to replace DRAM as the next generation main memory due to its higher scalability and lower leakage power. However, the high write power consumption has become a major challenge in adopting PCM as main memory. In addition to the fact that writing to PCM cells requires high write current and voltage, current loss in the charge pumps also contributes a large percentage of high power consumption. The pumping eficiency of a PCM chip is a concave function of the write current. Leveraging the characteristics of the concave function, the overall pumping eficiency can be improved if the write current is uniform. In this article, we propose a peak-to-average (PTA) write scheme, which smooths the write current fluctuation by regrouping write units. In particular, we calculate the current requirements for each write unit by their values when they are evicted from the last level cache (LLC). When the write units are waiting in the memory controller, we regroup the write units by LLC-assisted PTA to reach the current-uniform goal. Experimental results show that LLC-assisted PTA achieved 13.4% of overall energy saving compared to the baseline.",
keywords = "Charge pump, Phase change memory (PCM), Pumping eficiency, Write regrouping",
author = "Huizhang Luo and Qing Liu and Jingtong Hu and Qiao Li and Liang Shi and Qingfeng Zhuge and Sha, {Edwin H.M.}",
note = "Funding Information: A preliminary vision of this work appears in the proceedings of 21th Asia and South Pacific Design Automation Conference (ASP-DAC 2016) (Luo et al. 2016). This work is partially supported by NSFC 61472052, NSFC (61772092), US NSF under Grant No. CCF-1812861, and NJIT Research Startup Funds. Authors{\textquoteright} addresses: H. Luo and Q. Liu, 323 Dr Martin Luther King Jr Blvd, Newark, NJ 07102; emails: {huizhang.luo, qing.liu}@njit.edu; J. Hu, 4200 Fifth Ave, Pittsburgh, PA 15260; email: jthu@pitt.edu; Q. Li, Tat Chee Ave, Kowloon Tong, Hong Kong; email: qiaoli045@gmail.com; L. Shi, Q. Zhuge, and E. H.-M. Sha, 3663 North Zhongshan Road, Shanghai 200062, P.R. China; emails: {qfzhuge, shi.liang.hk, edwinsha}@gmail.com. Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page. Copyrights for components of this work owned by others than ACM must be honored. Abstracting with credit is permitted. To copy otherwise, or republish, to post on servers or to redistribute to lists, requires prior specific permission and/or a fee. Request permissions from permissions@acm.org. {\textcopyright} 2018 Association for Computing Machinery. 1553-3077/2018/11-ART27 $15.00 https://doi.org/10.1145/3200139 Funding Information: This work is partially supported by NSFC 61472052, NSFC (61772092), US NSF under Grant No. CCF-1812861, and NJIT Research Startup Funds. Publisher Copyright: {\textcopyright} 2018 Association for Computing Machinery.",
year = "2018",
month = nov,
doi = "10.1145/3200139",
language = "English (US)",
volume = "14",
journal = "ACM Transactions on Storage",
issn = "1553-3077",
publisher = "Association for Computing Machinery (ACM)",
number = "3",
}