Speaker: Mengying Zhao, City University of Hong Kong

Time: 9:00- 10:00 am, Jan. 29, 2015

Venue: Room 202, Second Floor, Office Building, Software Campus

Host：Baoquan Chen

Title: Qualifying PCM-based Main Memory for Embedded Systems

Abstract: Since the fabrication size is continuously shrinking, DRAM-based memory is hitting both the scaling and power walls. Emerging non-volatile memory brings new storage concepts and becomes long-term alternative of traditional memory in future embedded systems. Among emerging non-volatile memories, phase change memory (PCM) is proposed to serve as main memory due to its high scalability, near-zero leakage power and non-volatility. The disadvantages of PCM are the high access cost and lower endurance, which need to be taken care of to widen the utilization of PCM in next-generation embedded systems.

This talk first introduces the endurance problem of PCM, and then discusses approaches aiming at endurance enhancement. Two schemes are presented: one is a bit-level wear leveling design which balances the number of writes across multiple bits; the other is a mode transformation scheme between multiple level cell and single level cells. On the basis of effective optimizations in endurance, PCM is believed to be a promising memory candidate in future embedded systems.

Bio: Mengying Zhao received bachelor degree in Computer Science and Technology from Shandong University in China in 2011. She is now a PhD candidate in the Department of Computer Science, City University of Hong Kong. Her research interests include embedded and real-time systems, non-volatile memory and architectural optimizations.