"Exploration of Register and Cache-Level Nonvolatile Processor Design for Energy Harvesting Sensing System"

Yongpan Liu, Associate Professor, EE, Tsinghua University

April 23rd (Thursday), 11:00am
Harold Frank Hall (HFH), Room 4164

Energy harvesting has been widely investigated as a promising method of providing power for ultra-low-power applications. Such energy sources include solar energy, radio- frequency (RF) radiation, piezoelectricity, thermal gradients, etc. However, the power supplied by these sources is highly unreliable and dependent upon ambient environment factors. Hence, it is necessary to develop specialized systems that are tolerant to this power variation, and also capable of making forward progress on the computation tasks.

With the emerging memory technologies, nonvolatile processors are manufactured with nonvolatile registers and can work reliably under the environments with frequency power interrupts, such as energy harvesting and wireless powered applications. What’s more, it also has the following advantages: I) zero-standby power; II) instant on and off; III) high resilience to power failures; IV) fine-grained power management support.

This talk will first present a fabricated nonvolatile processor based on the ferroelectric flip-flops to demonstrate the conceptual design. Measured results show that it can operate continuously even under power failures occurring at 20KHz with 3us restore time, which achieves 2-4 magnitudes improvement on the wakeup time and energy compared with the state-of-the-art processors. Furthermore, different architectures of nonvolatile processors are explored under different power traces and power management strategies for maximizing forward progress. Third, a nonvolatile sensing platform is developed and several interesting applications based on the unique nonvolatile processor are discussed. Finally, some research opportunities and challenges associated with the nonvolatile processors will be given out for collaborations.

About Yongpan Liu:

photo of y.liu” width= Dr. Yongpan Liu received his B.S., M.S. and Ph.D. degrees from Electronic Engineering Department, Tsinghua University in 1999, 2002 and 2007. He has been a visiting scholar at Penn State University during summer 2014. He is a key member of Tsinghua-Rohm Research Center and Research Center of Future ICs. He is now an associate professor in Dept. of Electronic Engineering Tsinghua University. His main research interests include nonvolatile computation, low power VLSI design, emerging circuits and systems and design automation. His research is supported by NSFC, 863, 973 Program and Industry Companies such as Huawei, Rohm, Intel and so on. He has published over 60 peer-reviewed conference and journal papers and led over 6 chip design projects for sensing applications, including the first nonvolatile processor (THU1010N) and has received Design Contest Awards from (ISLPED2012, ISLPED2013) and best paper award HPCA2015. He is an IEEE(ACM,IEICE) member and served on several conference technical program committees (DAC, ASP-DAC, ISLPED, A-SSCC, ICCD, VLSI-D, etc).

Hosted by: Yuan Xie