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JST Press Release

Feb. 13, 2014
Japan Science and Technology Agency (JST)
5-3, Yonbancho, Chiyoda-ku, Tokyo 102-8666
URL http://www.jst.go.jp/EN/index.html

“Hybrid Storage of ReRAM/TLC NAND Flash with RAID-5/6 for Cloud Data Centers with Improved Reliability of 69℅ in ReRAM and 98℅ in NAND” and “An Electromagnetic Clip Connector for In-Vehicle LAN to Reduce Wire Harness Weight by 30℅”

A hybrid storage architecture of ReRAM and TLC (3bit/cell) NAND Flash with RAID-5/6 is developed to meet the cloud data center’s requirements of reliability, speed and capacity. The proposed storage controller enhances reliability and performance by 5 techniques, with minimal area overhead. The first 3 approaches, (i) Flexible RRef (FR), (ii) Adaptive Asymmetric Coding (AAC), and (iii) Verify Trials Reduction (VTR), are applied to 50nm ReRAM to improve the bit-error rate (BER) by 69℅ and performance by 97℅. Techniques (iv) Balanced RAID-5/6 and (v) Bits/Cell Optimization (BCO) are applied to 2Xnm TLC NAND to reduce the failure rate by 98℅ and extend the lifetime (write/erase (W/E) cycles) by >22×, respectively.

A bi-directional transmission line coupler (BD-TLC) based electromagnetic clip connector (EM-Clip) is proposed that can be used to make LAN connections like clips. This connector can reduce wire harness weight by 30℅. Forward error correction (FEC) is performed by oversampling Manchester encoding on the transmitter side and majority voting on the receiver side. High noise immunity is achieved through synchronous receiving by extraction of the clock signal from the received Manchester encoded data. For that purpose, a digital clock recovery circuit is developed that is robust against manufacturing variation and noise. Communication tests were conducted at 280Mbps with 10 transceivers fabricated in 65nm CMOS technology connected by a 10m unshielded twisted pair cable. Evaluation of the bit error rate (BER) and radiation spectrum confirmed that the ISO specifications concerning electromagnetic susceptibility (EMS) and the CISPR ones concerning electromagnetic interference (EMI) are satisfied.

Researcher Information

JST CREST
Research Area:“Fundamental technologies for dependable VLSI system”
Research Theme: “Dependable Wireless Solid-State Drive (SSD) ”

Conference Information

Shuhei Tanakamaru, Hiroki Yamazawa, Tsukasa Tokutomi, Sheyang Ning and Ken Takeuchi,
Hybrid Storage of ReRAM/TLC NAND Flash with RAID-5/6 for Cloud Data Centers,”
IEEE International Solid-State Circuits Conference (ISSCC), February 2014.
doi: 10.1109/ISSCC.2014.6757459

Atsutake Kosuge, Shu Ishizuka, Lechang Liu, Akira Okada,Masao Taguchi, Hiroki Ishikuro and Tadahiro Kuroda, “An Electromagnetic Clip Connector for In-Vehicle LAN to Reduce Wire Harness Weight by 30℅,”
IEEE International Solid-State Circuits Conference (ISSCC), February 2014.
doi: 10.1109/ISSCC.2014.6757528
Link to the conference: http://isscc.org/

Contact

[About Research]

Ken Takeuchi, Ph.D.
Professor, Chuo University, Department of Electrical, Electronic and Communication Engineering
E-mail:
URL: http://www.takeuchi-lab.org

Tadahiro Kuroda, Ph.D.
Professor, Keio University, Department of Electronics and Electrical Engineering
E-mail:
URL: http://www.kuroda.elec.keio.ac.jp

Hiroki Ishikuro, Ph.D.
Associate Professor, Keio University, Department of Electronics and Electrical Engineering
E-mail:
URL: http://www.iskr.elec.keio.ac.jp/

[About Program]

Koji Matsuo
ICT Group, Department of Innovation Research, JST
E-mail:

Japanese


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