The performance bottleneck of NAND flash-based storage devices (NFSDs) is mainly due to the slow NAND flash memories (NFMs). One of the well-known techniques for overcoming the bottleneck is an interleaving technique. This technique aims to maximize the utilization of high-speed channels by allowing slow NFMs to operate in parallel. Typically, NFSDs hierarchically apply the multilevel interleaving technique-channel, way, and die-level. While channel/way-level interleaving has already matured, die-level interleaving faces practical difficulties. The most critical issue is that it is not easy to identify individual die status because multiple dies in a package share a status pin, because of the form factor and cost issues of NFSDs. For this reason, NFSD has to issue a read status (RS) command to check the die status, which requires nonmarginal performance overhead. Moreover, the RS overhead attenuates the advantages of channel sneaking (CS) introduced in this brief to accelerate interleaving. To tackle this issue, we propose interrupt-based CS (ICS) that maximizes the impact of die-level interleaving while paying marginal overhead for identifying the die status. ICS performs on-demand die-status monitoring with minor modification of the NFM interface. We prove its effectiveness by conducting experiments in which ICS improves the performance by 19.8% over the typical scheme.
|Number of pages||5|
|Journal||IEEE Transactions on Very Large Scale Integration (VLSI) Systems|
|Publication status||Published - 2018 Sep|
Bibliographical noteFunding Information:
Manuscript received September 26, 2017; revised December 31, 2017 and February 24, 2018; accepted March 28, 2018. Date of publication April 20, 2018; date of current version August 23, 2018. This work was sup- ported in part by the National Research Foundation of Korea under Grant 2016R1A2B4011799, in part by the ICT Research and Development program of MSIP/IITP under Grant 2016(R7177-16-0233), and in part by Samsung Electronics Company, Ltd., Suwon, South Korea. (Corresponding author: Eui-Young Chung.) The authors are with the Department of Electrical and Electronic Engineer- ing, Yonsei University, Seoul, South Korea (e-mail: email@example.com). 2The page size of NFM has increased from 2 to 16 KB.
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All Science Journal Classification (ASJC) codes
- Hardware and Architecture
- Electrical and Electronic Engineering