Q&A: Ayse Kivilcim Coskun (Engineer, BU)

Ayse Kivilcim Coskun’s research on 3-D stacked systems has gained notoriety in academia, and it could change the way electrical engineers and chip manufacturers think about energy efficiency for years to come. In a recent interview, the Boston University engineering professor briefed us on her work and explained how she came to focus on the topics of green computing and 3-D systems.

Boston University professor Ayse Kivilcim Coskun

The following is an excerpt from an interview that appears in Circuit Cellar 264 (July 2012), which is currently on newsstands.

NAN: When did you first become interested in computer engineering?

AYSE: I’ve been interested in electronics since high school and in science and physics since I was little. My undergraduate major was microelectronics engineering. I actually did not start studying computer engineering officially until graduate school at University of California, San Diego. However, during my undergraduate education, I started taking programming, operating systems, logic design, and computer architecture classes, which spiked my interest in the area.

NAN: Tell us about your teaching position at the Electrical and Computer Engineering Department at Boston University (BU).

AYSE: I have been an assistant professor at BU for almost three years. I teach Introduction to Software Engineering to undergraduates and Introduction to Embedded systems to graduate students. I enjoy that both courses develop computational thinking as well as hands-on implementation skills. It’s great to see the students learning to build systems and have fun while learning.

NAN: As an engineering professor, you have some insight into what excites future engineers. What “hot topics” currently interest your students?

AYSE: Programming and software design in general are certainly attracting a lot of interest. Our introductory software engineering class is attracting a growing number of students across the College of Engineering every year. DSP, image processing, and security are also hot topics among the students. Our engineering students are very keen on seeing a working system at the end of their class projects. Some project examples from my embedded systems class include embedded low-power gaming consoles, autonomous toy vehicles, and embedded systems focusing on healthcare or security applications …

NAN: How did you come to focus on energy efficiency and thermal challenges?

AYSE: Energy efficiency has been a hot topic for embedded systems for several decades, mainly due to battery-life restrictions. With the growth of computing sources at all levels—from embedded to large-scale computers, and following the move to data centers and the cloud—now energy efficiency is a major bottleneck for any computing system. The focus on energy efficiency and temperature management among the academic community was increasing when I started my PhD. I got especially interested in thermally induced problems as I also had some background on fault tolerance and reliability topics. I thought it would be interesting to leverage job scheduling to improve thermal behavior and my advisor liked the idea too. Temperature-aware job scheduling in multiprocessor systems was the first energy-efficiency related project I worked on.

NAN: In May 2011, you were awarded the A. Richard Newton Graduate Scholarship at the Design Automation Conference (DAC) for a joint project, “3-D Systems for Low-Power High-Performance Computing.” Tell us about the project and how you became involved.

AYSE: My vision is that 3-D stacked systems—where multiple dies are stacked together into a single chip—can provide significant benefits in energy efficiency. However, there are design, modeling, and management challenges that need to be addressed in order to simultaneously achieve energy efficiency and reliability. For example, stacking enables putting DRAM and processor cores together on a single 3-D chip. This means we can cut down the memory access latency, which is the main performance bottleneck for a lot of applications today. This gain in performance could be leveraged to run processors at a lower speed or use simpler cores, which would enable low-power, high-performance computing. Or we can use the reduction in memory latency to boost performance of single-chip multicore systems. Higher performance, however, means higher power and temperature. Thermal challenges are already pressing concerns for 3-D design, as cooling these systems is difficult. The project focuses on simultaneously analyzing performance, power, and temperature and using this analysis to design system management methods that maximize performance under power or thermal constraints.

I started researching 3-D systems during a summer internship at  the Swiss Federal Institute of Technology (EPFL) in the last year of my PhD. Now, the area is maturing and there are even some 3-D prototype systems being designed. I think it is an exciting time for 3-D research as we’ll start seeing a larger pool of commercial 3-D stacked chips in a few years. The A. Richard Newton scholarship enabled us to do the preliminary research and collect results. Following the scholarship, I also received a National Science Foundation (NSF) CAREER award for designing innovative strategies for modeling and management of 3-D stacked systems.

The entire interview appears in Circuit Cellar 264  (July 2012).

Electronics Engineering Crossword (Issue 264)

The answers to Circuit Cellar’s July Electronics Engineer crossword puzzle are now available.

Issue 264 crossword answers


3.     IONIZATION—Occurs when an atom or molecule gains either and positive or negative charge

4.     ANDROIDPHONE—In “Audio-Enhanced Touch Sensors” (Circuit Cellar, May 2012), Matt Oppenheim said one of the stumbling blocks of using this for data collection is that it will try to recharge itself whenever you connect it to a USB port. [two words]

6.     FOLTZER—Circuit Cellar interviewee who participated in Motorola’s IEEE-802 MAC subcommittee on token-passing access control methods. [two words]

13.   COORDINATEDUNIVERSALTIME—A method of keeping the world in sync [three words]

14.   CICCHINELLI—Circuit Cellar published his book about a commonly used computer programming language in 2010

17.   HACKSPACE—i.e, “a circuit cellar”

18.   CHIP—A basic component of an electronic device

19.   VOLTAGEREFERENCE—National Semiconductor’s LM385 series is an example of an adjustable one. [three words]


1.     DOPPLEREFFECT—A phenomenon that occurs when a vehicle sounding a siren approaches, passes, and recedes from an observer [two words]

2.     WAVEFORMGENERATOR—A device that produces electronic signals [two words]

5.     ANGSTROM—Equals 1/10,000,000,000 m

7.     ISOTHERMALPROCESS— ΔT = 0 [two words]

8.     COMPARATOR—A device that compares two voltages or currents and switches its output to indicate which is larger

9.     NSPE—Organization formed in 1934 by bridge engineer David Steinman

10.   EMI—Acronym; common cause of electronic data corruption and subject of Novacek’s December 2011 Circuit Cellar article [two words]

11.   PIEZOELECTRICITY—Occurs when crystals acquire a charge after being compressed, twisted, or distorted (e.g., quartz)

12.   WIDLAR—American electrical engineer (1937–1991); IC pioneer

15.   LEDDRIVER—Circuitry that regulates or provides powers to a light source [two words]

16.   JOULE—Symbolized by 10th letter of the alphabet

20.   RTOS—Hint: acronym. Unscramble the following: IETEORGSEPSMNYMRLTIAEAT

CC264: Plan, Construct, and Secure

Circuit Cellar July 2012 features innovative ideas for embedded design projects, handy design tips with real-world examples, and essential information on embedded design planning and security. A particularly interesting topic covered in this issue is the microcontroller-based home control systems (HCS). Interest in building and HCSes never wanes. In fact, articles about such projects have appeared in this magazine since 1988.

Circuit Cellar 264 (July 2012) is now available.

Turn to page 18 for the first HCS-related article. John Breitenbach details how he built an Internet-enabled, cloud-based attic monitoring system. Turn to page 36 for another HCS article. Tommy Tyler explains how to build a handy MCU-based digital thermometer. You can construct a similar system for your home, or you can apply what you learn to a variety of other temperature-sensing applications. Are you currently working on a home automation design or industrial control system? Check out Richard Wotiz’s “EtherCAT Orchestra” (p. 52). He describes an innovative industrial control network built around seven embedded controllers.

John Breitenbach's DIY leak-monitoring system

The wiring diagram for Tommy Tyler's MCU-based digital thermometer

The rest of the articles in the issue cover essential electrical engineering concepts and design techniques. Engineers of every skill level will find the information immediately applicable to the projects on their workbenches.

Tom Struzik’s article on USB is a good introduction to the technology, and it details how to effectively customize an I/O and data transfer solution (p. 28). On page 44, Patrick Schaumont introduces the topic of electronic signatures and then details how to use them to sign firmware updates. George Novacek provides a project development road map for professionals and novices alike (p. 58). Flip to page 62 for George Martin’s insight on switch debouncing and interfacing to a simple device. On page 68, Jeff Bachiochi tackles the concepts of wireless data delivery and time stamping.

Jeff Bachiochi's hand-wired modules

I encourage you to read the interview with Boston University professor Ayse Kivilcim Coskun on page 26. Her research on 3-D stacked systems has gained notoriety in academia, and it could change the way electrical engineers and chip manufacturers think about energy efficiency for years to come. If you’re an engineer fascinated by “green computing,” you’ll find Coskun’s work particularly intriguing.

Special note: The Circuit Cellar staff dedicates this issue to Richard Alan Wotiz who passed away on May 30, 2012. We appreciate having had the opportunity to publish articles about his inventive projects and innovative engineering ideas and solutions. We extend our condolences to his family and friends.

Circuit Cellar Issue 264 (July 2012) is now available on newsstands. Go to Circuit Cellar Digital and then select “Free Preview” to take a look at the first several pages.