Sep 23 (Fri) @2:00pm: "Scale up Your In-Memory Computing: A Heterogenous Paradigm," Yu Cao, Prof. EE, ASU

Date and Time
Harold Frank Hall (HFH), Rm 4164


Contemporary microprocessor design is facing tremendous challenges in memory bandwidth and power consumption. In-memory computing (IMC) helps relieve some issues, achieving massively parallel computing with high storage density. On the other hand, its scaling trend is still lagging behind the ever-increasing demand of AI algorithms and high-definition sensors. More disruptive innovations, such as heterogeneous integration, will be critical to scaling up the system and speeding up the computation.

In this talk, we will first review the fundamental limitations of current IMC system: device variations, peripheral circuits, and interconnection. They interact with each other, limiting the accuracy, scalability, and energy efficiency of the system. Then we will present heterogeneous solutions crossing device/circuit/architecture, based on statistical data from a fully integrated 65nm CMOS/RRAM test chip. At the circuit level, we design a hybrid RRAM/SRAM macro to fully recover the accuracy loss, employing sparse training on silicon; at the architecture level, we propose big-little IMC chiplets to maximize the utilization and minimize energy consumption.

To efficiently explore the design space, we further develop a new benchmark simulator, SIAM, for the heterogenous IMC system, which models device/circuit/architecture, network-on-chip (NoC), network-on-package (NoP) and DRAM access to address the challenges in 2.5D/3D integration. We will conclude this talk with brainstorming on the potential and research need of such a design paradigm shift.


Yu Cao received the B.S. degree in physics from Peking University in 1996. He received the M.A. degree in biophysics and the Ph.D. degree in electrical engineering from University of California, Berkeley, in 1999 and 2002, respectively.

He is now a Professor of Electrical Engineering at Arizona State University, Tempe, Arizona. He has published numerous articles and two books on nano-CMOS modeling and physical design. His research interests include neural-inspired computing, hardware design for on-chip learning, and reliable integration of nanoelectronics.

Dr. Cao is a Distinguished Lecturer of the IEEE Circuits and Systems Society. He was a recipient of the 2020 Intel Outstanding Researcher Award, the 2009 ACM SIGDA Outstanding New Faculty Award, the 2006 NSF CAREER Award, the 2006 and 2007 IBM Faculty Award, and five Best Paper Awards. He is a Fellow of the IEEE.

Hosted by: Prof. Zheng Zhang

Submitted by: Zheng Zhang <>