Bruce Jacob University of Maryland Memory-Systems Research Keystone Professor and Director of Computer Engineering Department of Electrical & Computer Engineering University of Maryland at College Park College Park, MD 20742 E-mail: WWW: http://www.ece.umd.edu/~blj/ Photo: Axel Persaud (a former student and photographer-on-the-side)

Fall 2009: ENEE 350H, Computer Organization
Fall 2009: ENES 100, Introduction to Engineering Design
Office Hours: Open-door

Office: 1325 A.V. Williams
Phone: +1 301-405-0432
Fax: +1 301-314-9281

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Twitter feed: http://twitter.com/brucejacob

Curriculum Vitae in PDF format (a bit more thorough than this webpage, if a bit out of date)

Brief NSF/IEEE-style bio (for when you need such things)

Education

• A.B. (Mathematics, cum laude) Harvard University - Cambridge MA, 1988
• M.S. (Computer Science & Engineering) University of Michigan - Ann Arbor MI, 1995
• Ph.D. (Computer Science & Engineering) University of Michigan - Ann Arbor MI, 1997

Industry Experience

• Software Engineer, Boston Technology - Cambridge MA + Wakefield MA, 1989-1991
  (now part of Comverse Network Systems [who seem to have changed their name to Comverse Technology {and now just 'Comverse'}])
• Chief Engineer & System Architect, Priority Call Management - Wilmington MA, 1991-1992
  (now part of LHS Group [which is actually now part of Sema Group {which seems to be part of Schlumberger at this point ... I'm losing track}])
  (and, as of 2004, they're part of uReach Technologies ... I think I will give up on keeping this up-to-date)

Computational Artifacts

• DRAMsim, our public-domain DRAM-system simulator, at http://www.ece.umd.edu/dramsim
• BioBench, our set of bioinformatics workloads, at http://www.ece.umd.edu/biobench

Honors & Awards

• Clark School of Engineering Keystone Professor, 2006
• University of Maryland "Research Leader," 2006
• University of Maryland "Rainmaker," 2005
• IBM Shared University Research Award, 2005
• University of Maryland Award for Teaching Excellence, 2004
• Tenure Awarded, 2003
• University of Maryland "Rainmaker," 2001
• National Science Foundation CAREER Award, 2000
• ECE Department George Corcoran Award, 1999

Research Interests

• Memory systems (DRAM systems, virtual memory, cache design, etc.)
  
• Embedded systems (SimBed, low-power issues, real-time caches, hardware support for RTOSes, etc.)
• Circuit integrity (EMI issues and EMI-tolerant architectures, RF measurements, thermal issues, etc.)
• Computer architecture & microarchitecture
• Low-level operating systems design
• Verilog modeling (e.g. 16-bit out-of-order RiSC-16)
• Algorithmic composition (e.g. some composition software and MP3's of a 35-minute orchestral piece)

University of Maryland Memory-Systems Research

• Overview & FAQ
• Computational artifacts
• Workloads and their characterization
• The many, many studies

Research Group: Grad Students, 2003 Grad Students, 2006

Selected Publications

2010	Technology Management	"Reward: How to foster a technology-innovation culture within a large organization (What you can learn from startup companies)." Bruce Jacob. Chapter 69 in The Handbook of Technology Management. H. Bidgoli, Editor. John Wiley & Sons: Hoboken NJ. 2010.
2009	ISCA	"The performance of PC Solid-State Disks (SSDs) as a function of bandwidth, concurrency, device architecture, and system organization." Cagdas Dirik and Bruce Jacob. Proc. 36th International Symposium on Computer Architecture (ISCA 2009), pp. 279-289. Austin TX, June 2009.
	Morgan Claypool book	The Memory System: You Can't Avoid It; You Can't Ignore It; You Can't Fake It. Bruce Jacob, with contributions by Sadagopan Srinivasan and David T. Wang. ISBN 978-1598295870. Morgan & Claypool Publishers, June 2009. Clicking the link above or the image of the cover should take you to the Morgan-Clypool website.
	MoBS	"CMP memory modeling: How much does accuracy matter?" S. Srinivasan, L. Zhao, B. Ganesh, B. Jacob, M. Espig, and R. Iyer. Proc. Fifth Annual Workshop on Modeling, Benchmarking and Simulation (MoBS), pp. 24-33. Austin TX, June 2009.
2008	TECS	"Accurate and fast system-level power modeling: An XScale-based case study." A. Varma, E. Debes, I. Kozintsev, P. Klein, and B. Jacob. ACM Transactions on Embedded Computing Systems, vol. 7, no. 4, pp. 25:1-20. April 2008.
	MoBS	"CMP$im: A Pin-based on-the-fly multi-core cache simulator." Aamer Jaleel, Robert S. Cohn, Chi-Keung Luk, and Bruce Jacob. Proc. Fourth Annual Workshop on Modeling, Benchmarking and Simulation (MoBS), pp. 28-36. Beijing China, June 2008.
2007	Open letter	"On supporting a high-tech cottage industry ... an open letter to the engineering-education community." Bruce Jacob. December 2007.
	Morgan Kaufmann book	Memory Systems: Cache, DRAM, Disk. Bruce Jacob, Spencer W. Ng, and David T. Wang, with contributions by Samuel Rodriguez. ISBN 978-0123797513. Morgan Kaufmann Publishers, September 2007. Approx. 1000 pages and half a million words according to Translator's Abacus. PDF for several parts of the book: the Overview chapter, "On Memory Systems and Their Design" the front matter, including reviewer quotes, table of contents, and the preface "It's the Memory, Stupid!" (alluding to Dick Sites' 1996 MPR article) References/bibliography/list of citations from the book Memory Systems: Cache, DRAM, Disk (included in case any of the various on-line citation databases are sophisticated enough to extract the info) Clicking the link above or the image of the cover should take you to the Morgan Kaufmann website, where you can get yourself one of these rare beauties. Alternatively: check it out on Amazon.com, or save a few bucks and get it on Alibris.
	HPCA	"Fully-Buffered DIMM memory architectures: Understanding mechanisms, overheads and scaling." Brinda Ganesh, Aamer Jaleel, David Wang, and Bruce Jacob. Proc. 13th International Symposium on High Performance Computer Architecture (HPCA 2007), pp. 109-120. Phoenix AZ, February 2007.
	TECS	"Accurate and fast system-level power modeling: An XScale-based case study." A. Varma, B. Jacob, E. Debes, I. Kozintsev, and P. Klein. ACM Transactions on Embedded Computing Systems, vol. 6, no. 4, pp. 26:1-20. September 2007. (TECS Special Issue on best papers from LCTES'05)
2006	CASES	"Modeling heterogeneous SoCs with SystemC: A digital/MEMS case study." A. Varma, Y. Afridi, A. Akturk, P. Klein, A. Hefner, and B. Jacob. Proc. International Conference on Compilers, Architectures, and Synthesis for Embedded Systems (CASES 2006), pp. 54-64. Seoul Korea, October 2006.
	ISLPED	"Energy/power breakdown of pipelined nanometer caches (90nm/65nm/45nm/32nm)." Samuel V. Rodriguez and Bruce Jacob. Proc. International Symposium on Low Power Electronics and Design (ISLPED 2006), pp. 25-30. Tegernsee Germany, October 2006.
	HPCA	"Last-level cache (LLC) performance of data-mining workloads on a CMP--A case study of parallel bioinformatics workloads." Aamer Jaleel, Matthew Mattina, and Bruce Jacob. Proc. 12th International Symposium on High Performance Computer Architecture (HPCA 2006), pp. 88-98. Austin TX, February 2006.
	E&M	"Electromagnetic interference and digital circuits: An initial study of clock networks." Hongxia Wang, Samuel V. Rodriguez, Cagdas Dirik, and Bruce Jacob. Electromagnetics, vol. 26, no. 1, pp. 73-86. January 2006. (Special Issue: RF effects on Digital Systems)
	IEEE-TC	"In-line interrupt handling and lock-up free translation lookaside buffers (TLBs)." Aamer Jaleel and Bruce Jacob. IEEE Transactions on Computers, vol. 55, no. 5, pp. 559-574. May 2006.
2005	HPCA	"Using Virtual Load/Store Queues (VLSQs) to reduce the negative effects of reordered memory instructions." Aamer Jaleel and Bruce Jacob. Proc. 11th International Symposium on High Performance Computer Architecture (HPCA 2005), pp. 191-200. San Francisco CA, February 2005.
	ISPASS	"BioBench: A benchmark suite of bioinformatics applications." K. Albayraktaroglu, A. Jaleel, X. Wu, M. Franklin, B. Jacob, C.-W. Tseng, and D. Yeung. Proc. 2005 IEEE International Symposium on Performance Analysis of Systems and Software (ISPASS 2005), pp. 2-9. Austin TX, March 2005.
	SIGARCH	"DRAMsim: A memory-system simulator." David Wang, Brinda Ganesh, Nuengwong Tuaycharoen, Katie Baynes, Aamer Jaleel, and Bruce Jacob. SIGARCH Computer Architecture News, vol. 33, no. 4, pp. 100-107. September 2005.
	MSP	"Performance characteristics of MAUI: An intelligent memory system architecture." Justin Teller, Charles Silio, and Bruce Jacob. Proc. 2005 Workshop on Memory System Performance (MSP 2005), pp. 44-53. Chicago IL, June 2005.
2004	ISCA	"Extended Split-Issue: Enabling flexibility in the hardware implementation of NUAL VLIW DSPs." Bharath Iyer, Sadagopan Srinivasan, and Bruce Jacob. Proc. 31st International Symposium on Computer Architecture (ISCA 2004), pp. 364-375. Munchen Germany, June 2004.
	EMC	"Radio frequency effects on the clock networks of digital circuits." Hongxia Wang, Cagdas Dirik, Samuel V. Rodriguez, Amol V. Gole and Bruce Jacob. Proc. IEEE International Symposium on Electromagnetic Compatibility (EMC 2004), pp. 93-96. Santa Clara CA, August 2004.
	JSSE	"MEMS-based embedded sensor virtual components for system-on-a-chip (SoC)." M. Afridi, A. Hefner, D. Berning, C. Ellenwood, A. Varma, B. Jacob, S. Semancik. Journal of Solid-State Electronics, vol. 48, no. 10/11, pp. 1777-1781. October/November 2004.
2003	CASES	"A control-theoretic approach to dynamic voltage scheduling." A. Varma, B. Ganesh, M. Sen, S. R. Choudhary, L. Srinivasan, and B. Jacob. Proc. International Conference on Compilers, Architectures, and Synthesis for Embedded Systems (CASES 2003), pp. 255-266. San Jose CA, October 2003.
	CODES+ISSS	"Hardware support for real-time operating systems." Paul Kohout, Brinda Ganesh, and Bruce Jacob. Proc. First IEEE/ACM/IFIP International Conference on Hardware/Software Codesign and System Synthesis (CODES+ISSS 2003), pp. 45-51. Newport Beach CA, October 2003.
	IEEE-TC	"The performance and energy consumption of embedded real-time operating systems." K. Baynes, C. Collins, E. Fiterman, B. Ganesh, P. Kohout, C. Smit, T. Zhang, and B. Jacob. IEEE Transactions on Computers, vol. 52, no. 11, pp. 1454-1469. November 2003.
	IEEE Micro	"A case for studying DRAM issues at the system level." Bruce Jacob. IEEE Micro, vol. 23, no. 4, pp. 44-56. July/August 2003.
2001	ISCA	"Concurrency, latency, or system overhead: Which has the largest impact on uniprocessor DRAM-system performance?" Vinodh Cuppu and Bruce Jacob. Proc. 28th International Symposium on Computer Architecture (ISCA 2001), pp. 62-71. Goteborg Sweden, June 2001.
	CASES	"Transparent data-memory organizations for digital signal processors." Sadagopan Srinivasan, Vinodh Cuppu, and Bruce Jacob. Proc. International Conference on Compilers, Architecture, and Synthesis for Embedded Systems (CASES 2001), pp. 44-48. Atlanta GA, November 2001.
	CASES	"The performance and energy consumption of three embedded real-time operating systems." K. Baynes, C. Collins, E. Fiterman, B. Ganesh, P. Kohout, C. Smit, T. Zhang, and B. Jacob. Proc. International Conference on Compilers, Architecture, and Synthesis for Embedded Systems (CASES 2001), pp. 203-210. Atlanta GA, November 2001.
	IEEE-TC	"High performance DRAMs in workstation environments." Vinodh Cuppu, Bruce Jacob, Brian Davis, and Trevor Mudge. IEEE Transactions on Computers, vol. 50, no. 11, pp. 1133-1153. November 2001. (TC Special Issue on High-Performance Memory Systems)
	IEEE-TC	"Uniprocessor virtual memory without TLBs." Bruce Jacob and Trevor Mudge. IEEE Transactions on Computers, vol. 50, no. 5, pp. 482-499. May 2001.
1999	ISCA	"A performance comparison of contemporary DRAM architectures." Vinodh Cuppu, Bruce Jacob, Brian Davis, and Trevor Mudge. Proc. 26th International Symposium on Computer Architecture (ISCA 1999), pp. 222-233. Atlanta GA, May 1999.
	CASES	"Hardware/software architectures for real-time caching." Bruce Jacob. Proc. Second Workshop on Compiler and Architecture Support for Embedded Systems (CASES'99), pp. 135-138, Washington DC, October 1999. This paper gives a fully associative architecture for a software-managed cache design.
1998	ASPLOS	"A look at several memory management units, TLB-refill mechanisms, and page table organizations." Bruce Jacob and Trevor Mudge. Proc. Eighth International Conference on Architectural Support for Programming Languages and Operating Systems (ASPLOS 1998), pp. 295-306. San Jose CA, October 1998. The paper is also noteworthy for its coining of the term "software-managed cache."
	IEEE Micro	"Virtual memory in contemporary microprocessors." Bruce Jacob and Trevor Mudge. IEEE Micro, vol. 18, no. 4, pp. 60-75. July/August 1998.
	IEEE Computer	"Virtual memory: Issues of implementation." Bruce Jacob and Trevor Mudge. IEEE Computer, vol. 31, no. 6, pp. 33-43. June 1998.
	CASES	"Software-managed caches: Architectural support for real-time embedded systems." Bruce Jacob. CASES'98: Workshop on Compiler and Architecture Support for Embedded Systems. Washington DC, December 1998. The slides for the talk are available on-line in PDF format, and include details not found in the 2-page abstract.
1997	HPCA	"Software-managed address translation." Bruce Jacob and Trevor Mudge. Proc. Third International Symposium on High Performance Computer Architecture (HPCA'97), pp. 156-167, San Antonio TX, February 1997.
1996	Organised Sound	"Algorithmic composition as a model of creativity." Bruce Jacob. Organised Sound, vol. 1, no. 3, pp. 157-165. Cambridge University Press. December 1996.
	IEEE-TC	"An analytical model for designing memory hierarchies." Bruce Jacob, Peter Chen, Seth Silverman, and Trevor Mudge. IEEE Transactions on Computers, vol. 45, no. 10, pp. 1180-1194. October 1996.
1995	ICMC	"Composing with genetic algorithms." Bruce Jacob. Proc. International Computer Music Conference (ICMC '95), pp. 452-455. Banff Alberta, September 1995.

All Publications

Talks & Presentations

Students: Awards/Honors, Research Topics, and Theses

Student Honors:
Elizabeth Kenyon	Philip Merrill Presidential Scholar, October 2009.
Aamer Jaleel	Award for Best Paper Presentation, 11th International Symposium on High Performance Computer Architecture (HPCA 2005), February 2005.
Christine Smit	Chosen to be Student Speaker at University of Maryland Campus-Wide Commencement, May 20th, 2004.
Sandy Klemm	2002 Merit Fair First Place Winner for his undergraduate research on dynamic voltage scaling.
Current Students:
Elliott Cooper-Balis	DRAM architectures for low power. A novel technique is presented for significant power reduction in the DRAM system using existing protocols and minimal architectural modifications which are transparent to the memory controller, thereby appearing to be a standard part.
Joe Gross	DRAM systems, architectures, and protocols for supercomputer applications. Memory-system performance dominates overall processor and node performance in all modern computer systems. In particular, analysis of NNSA and Office of Science applications has demonstrated that typical codes pull in relatively large cache lines, use a small fraction of that line, then flush that line back to the memory system.
Paul Rosenfeld	Next-generation memory systems for multicore. Modern CPU trends such as multicore exacerbate the memory problem; yet just a handful of years ago, multicore was seen as a solution to the memory problem. This simply underscores the degree to which the ramifications of multicore designs and their interaction with the memory system are still largely misunderstood.
Hongxia Wang	Circuit integrity issues and electromagnetic interference. Due to reduced feature sizes, voltage levels, and switching delays, modern digital systems are becoming more susceptible to elecromagnetic emissions (noise), thermal effects, and voltage fluctuations. This work characterizes the EMI sources of circuit integrity issues: in particular, the exact nature of errors.
Ph.D. Theses:
Cagdas Dirik	Ph.D. 2009. Performance Analysis of NAND Flash Memory Solid-State Disks (SSDs) (SanDisk) NAND Flash Solid State Disks (SSDs) are becoming an increasingly attractive alternative to Hard Disk Drives (HDDs). It is important to understand the internals of solid state disk drives. This work provides an in-depth study of the relationship between SSD architectures, their management algorithms, and system-level performance, as well as proposing new optimization heuristics.
Sadagopan Srinivasan	Ph.D. 2007. Prefetching vs. the Memory System: Optimizations for Multi-core Server Platforms. (Intel) Investigates prefetching scheme for servers with respect to realistic memory systems. Real systems disable prefetching in server settings, suggesting that there is a fundamental disconnect between research and practice. This thesis shows that the disconnect is due to the use of simplistic memory models; experimental results suggest that using simplistic models can mis-predict the system performance by a factor of two.
Brinda Ganesh	Ph.D. 2007. Understanding and Optimizing High-Speed Serial Memory-System Protocols. (Intel) Next-generation memory systems such as the Fully-Buffered DIMM use a system topology more akin to a computer network than a traditional memory bus. Data movement in these systems is complicated by the bus organization, making it essential to understand the implications when designing schedulers for these systems.
Ankush Varma	Ph.D. 2007. High-Speed Performance, Power, and Thermal Co-Simulation for SoC Design. (Intel) Developing tools and methodologies for fast, accurate, high-level power and thermal modeling on SoCs. Exploring power/thermal modeling for MEMS, mixed-signal and digital SoC components, how these models can be built into high-level System Description Languages (such as SystemC), and how high-level power models can be made robust to low-level design decisions.
Nuengwong (Ohm) Tuaycharoen	Ph.D. 2006. Disk Design-Space Exploration in Terms of System-Level Performance, Power, and Energy Consumption. (Dhurakijpundit University) SYSim is a full-system simulator that integrates Bochs, Wattch, DRAMsim, and DiskSim, boots Linux, and enables complete memory hierarchy studies in both performance and power consumption domains. With it, we investigate the system-level impacts of disk- and DRAM-system technologies such as DRAM capacity, disk caching, disk speed, etc.
Samuel Rodriguez	Ph.D. 2006. myCACTI: A New Cache-Design Tool for Pipelined Nanometer Caches. (AMD) This dissertation shows that both CACTI and eCACTI still contain major limitations and even flaws in their design, making them unsuitable for use in very-deep submicron and nanometer caches, especially pipelined designs. These limitations and flaws are discussed in detail. This dissertation then introduces a new tool, called myCACTI, that addresses all these limitations and, in addition, introduces major enhancements to the simulation framework.
Aamer Jaleel	Ph.D. 2005. The Effects of Out-of-Order Execution on the Memory System. (Intel) Studies the deleterious effects of out-of-order execution. Common wisdom holds that bigger is better: to wit, the larger the instruction window, the better the performance. Numerous studies show this result, and, consequently, numerous other studies investigate low-cost ways to implement large instruction windows. This study shows that, once one includes a realistic model of the memory system, nearly all of those projected performance gains fail to materialize.
David Tawei Wang	Ph.D. 2005. Modern DRAM Memory Systems: Performance Analysis and a High Performance, Power-Constrained DRAM-Scheduling Algorithm. (MetaRAM) An in-depth treatment of modern, power-limited, DRAM systems. The timing parameters tFAW and tRRD, introduced at the DDR2 generation of DDRx SDRAM, have a deleterious effect on system-level performance, significantly limiting sustainable bandwidth. The work characterizes the problem and provides a scheduling algorithm that offers a solution. As of February 2008, MetaRAM is now radar-visible. Fred, Dave, and Co. are set to take over the world.
Brian Davis	Ph.D. 2001. Modern DRAM Architectures. (Michigan Tech) This thesis examines a variety of modern DRAM architectures in the context of current desktop workstations. The DRAM examined (EDO, Burst EDO, SDRAM, DDR, DDR2, Rambus, ESDRAM, FCRAM, VCM) include those which are available today, as well as a number of architectures which are expected to come to market in the near future. (co-advised by Trevor Mudge)
M.S. Theses:
Jeffrey Scott Smith	M.S. 2006. Distributed Two-Dimensional Fourier Transforms on DSPs with Applications for Phase Retrieval. (NASA)
Rami Nasr	M.S. 2005. FBsim and the Fully Buffered DIMM Memory System Architecture. (Lutron)
Amol Gole	M.S. 2003. TERPS: The Embedded Reliable Processing System. (General Dynamics Robotics Systems)
Bharath Iyer	M.S. 2003. Extended Split-Issue Mechanism in VLIW DSPs to Support SMT and Hardware-ISA Decoupling. (AMD)
Nuengwong (Ohm) Tuaycharoen	M.S. 2003. RTOS-Based Dynamic Voltage Scaling. (U. Maryland Ph.D. 2006)
Lei Zong	M.S. 2003. Nanoprocessors: Configurable Hardware Accelerators for Embedded Systems. (Army Research Lab)
Brinda Ganesh	M.S. 2002. Architectural Support for Embedded Operating Systems. (U. Maryland Ph.D. 2007)
Aamer Jaleel	M.S. 2002. In-Line Interrupt Handling and Lockup-Free TLBs. (U. Maryland Ph.D. 2005)
Paul Kohout	M.S. 2002. Hardware Support for Real-Time Operating Systems. (EVI Technology)
Tiebing Zhang	M.S. 2001. RTOS Performance and Energy Consumption Analysis Based on an Embedded System Testbed. (Aeptec Microsystems)
Christopher Collins	M.S. 2000. An Evaluation of Embedded System Behavior Using Full-System Software Emulation. (Intel)

Past, Present, and Future Classes

Spring 2009:	ENEE 459j, Consumer Electronics (Start-Up 101) ENEE 159b, Electric Guitar Design (Start-Up 101) ENES 100, Introduction to Engineering Design
Fall 2008:	ENEE 646, Digital Computer Design ENES 100, Introduction to Engineering Design
Spring 2008:	ENEE 359a, Digital VLSI Circuits ENEE 159b, Electric Guitar Design (Start-Up 101) ENES 100, Introduction to Engineering Design
Fall 2007:	ENEE 759h, High-Speed Memory Systems ENES 100, Introduction to Engineering Design
Spring 2007:	ENEE 359a, Digital VLSI Circuits ENES 100, Introduction to Engineering Design
Fall 2006:	ENEE 646, Digital Computer Design ENES 100, Introduction to Engineering Design
Spring 2006:	ENEE 446, Digital Computer Design
Fall 2005:	ENEE 302H, Digital Electronics
Spring 2005:	HONR 218V, Digital Sound and Fury on Mac OSX: Desktop Publishing, Music, Photography, and Video ENEE 759h, High-Speed Memory Systems
Fall 2004:	ENEE 302H, Digital Electronics
Spring 2004:	On sabbatical
Fall 2003:	On sabbatical
Spring 2003:	ENES 100, Introduction to Engineering Design ENEE 759h, High-Speed Memory Systems
Fall 2002:	ENEE 646, Digital Computer Design
Spring 2002:	ENEE 759m, Advanced Topics in Microarchitecture
Fall 2001:	ENEE 646, Digital Computer Design
Spring 2001:	ENEE 350, Computer Organization
Fall 2000:	ENEE 446, Digital Computer Design
Spring 2000:	ENEE 759m, Advanced Topics in Microarchitecture
Fall 1999:	ENEE 350, Computer Organization
Spring 1999:	ENEE 647, Distributed Computer Systems
Fall 1998:	ENEE 350H, Computer Organization ENEE 698b, Graduate Seminar in Computer Engineering
Spring 1998:	ENEE 759m, Advanced Topics in Microarchitecture
Fall 1997:	ENEE 350H, Computer Organization

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Research Statement: Embedded Systems, Memory Systems, and Embedded Memory Systems

Dr. Jacob's research interests are in the areas of embedded systems, memory-system design, circuit integrity, and memory management. The objective of his research is to build hardware/software systems that improve the performance, cost, reliability, real-time behavior (e.g. predictability), and/or power consumption of computer systems relative to existing designs. The techniques he uses include system modeling and simulation, in which one builds a computer program that emulates the behavior of the system under observation, and physical prototyping as well (his group has become quite adept at building experimental chips).

The memory systems projects include the analysis of DRAM architectures for improved memory-system performance, which is one of the first in-depth comparisons of different DRAM technologies. This research looks at both the DRAM architecture level (i.e. DRAM interfaces and protocols) and the DRAM system level (i.e. bus organizations and scheduling of transactions) and aims to reduce the gap between processor and memory performance.

The circuit-integrity projects include studying the effects of electromagnetic interference (EMI) on digital systems, developing EMI-mitigation technologies, studying thermal effects on digital systems, and looking at system-on-chip issues. These studies include the design and fabrication of real chips and PCBs to observe and measure phenomena and experimentally test models and proposed theories of behavior.

The embedded systems projects include the development of real-time mechanisms at the microarchitecture level and the re-design of a real-time operating system to take advantage of the novel mechanisms. In this work, real-time operating systems are run on top of simulated hardware to find low-power and high-resolution mechanisms in both hardware and software. This work also encompasses dynamic mechanisms for managing memory with real time guarantees and novel interrupt mechanisms that better suit the behavior of out-of-order processors. This work in architectures for real-time processing should speed up real-time systems significantly and allow systems with even moderate processing power to make tight deadline requirements.

External Support

• Department of Defense. Next-Generation DRAM-System Architectures and Optimizations. 11/2008-present. PI.

• Sandia National Laboratories. High Performance Memory-Systems Design and Optimization. 6/2008-12/2009. PI.

• National Institute of Standards and Technology. Integration Methodologies and Full System Verification for Heterogeneous Systems on Chip. 1/2007-1/2008. PI.

• Office of the Secretary of Defense. Focused Logistics Transformation and Sense & Respond Support. 9/2005-12/2007. Associated Researcher.

• National Science Foundation. MRI: Development of Energy-Efficient Embedded Systems for Wireless Sensor Networks. 8/2005-7/2008. Co-PI, with Ephremides (PI), Abshire, Barua, Petrov, Qu, Ulukus, and Vishkin.

• IBM Corporation. SUR Award: DRAM Device Configuration and Performance Scalability. 2/2005. PI.

• Cray Computer, Inc. High-Bandwidth Controller and System Design. 9/2004-11/2005. PI.

• Cray Computer, Inc. DDR3 Memory-System Configuration Sensitivity. 4/2004-9/2004. PI.

• National Institute of Standards and Technology. Embedded Sensor System-on-Chip Microcontroller Core and System Architecture Design. 8/2003-1/2008. PI.

• Department of Defense. Joint Program for Advanced Electronic Materials. 6/2003-5/2006. Co-PI, with C.H. Lee (PI), N. Goldsman, and C.H. Yang.

• National Science Foundation. ITR: Parallel Random-Access Model (PRAM)-On-Chip. 9/2003-9/2008. Co-PI, with U. Vishkin (PI), R. Barua, M. Franklin, and G. Qu.

• Air Force Office of Scientific Research, Multidisciplinary Research Program. Basic Studies of the Effect of Microwave Pulses on Electronics. 5/2001-4/2006. Co-PI, with Granatstein (PI), Anlage, Antonsen, Baker, Carmel, Goldsman, Iliadis, Melngailis, O'Shea, Ott, Ramahi, and Rodgers.

• National Science Foundation. Hardware-Software Co-Design of Real-Time Operating Systems and Embedded Microprocessors. 3/2001-3/2005. PI, with D. Stewart (Co-PI).

• National Science Foundation, CAREER Award. Architecture Issues in DRAM Devices and Systems. 1/2000-1/2004. PI.

• Compaq Computer Corporation. Evaluation of EV6 with Contemporary DRAM Architectures. 1999-2004. PI.

• IBM Corporation. The Study of Design Parameters for DDR DRAM and DDRII DRAM. 1999-2003. PI.

• National Science Foundation. Hardware-Software Co-Design of an Experimental Real-Time Operating System and a Microcontroller Architecture. 9/1998-9/2000. Co-PI, with D. Stewart (PI).

Memory Systems Research

DRAM Systems Research

Embedded Systems Research

Circuit Integrity Research

Research in Memory Management and Virtual Memory

Verilog code for a 16-bit out-of-order core (the RiSC-16)

Attention Students

Microarchitecture Information

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Other Important Stuff

• Microsoft is at it again. Ignore the bribe aspect; the main point is that they are vocal and proud about creating intentional incompatibilities within the web ecosphere. Here's a funny cartoon:

  

  ... and a nice discussion of the current problem/situation. Basically, they're doing the same thing that got them in trouble with the DOJ years ago: trying to screw with open standards.

  With my dad (a lawyer), I wrote a relatively lengthy article about Microsoft and the Browser Wars a while back. Never got around to publishing it -- the main idea was to influence the EU & DOJ in the remedy stage, which kind of worked ... the EU followed much of our advice, the DOJ guys talked to us at length and rewrote their initial remedies to mirror our suggestions. But then Bush got elected and a new DOJ effectively tossed the case out. US Politics FTW!

• The World According to Monsanto - A documentary that Americans won't ever see (1 hr 49 min)
  Description: On March 11 2008 a new documentary was aired on French television (ARTE - French-German cultural TV channel) by French journalist and film maker Marie-Monique Robin, The World According to Monsanto - A documentary that Americans won't ever see. The gigantic biotech corporation Monsanto is threatening to destroy the agricultural biodiversity which has served mankind for thousands of years.

• Evidently someone at Vanity Fair saw that documentary, because the magazine published an article May 2008 called "Monsanto's Harvest of Fear" which overlaps the film to a large degree.

• Scary quote: "We paid $3 Billion for these television stations. We will decide what the news is. The news is what we tell you it is."
  --David Boylan, station manager of Fox WTVT Channel 13 in Tampa Florida, to reporters Steve Wilson and Jane Akre, after they refused to broadcast an edited version of their news story about bovine growth hormone and the Monsanto Company. Wilson and Akre felt that the edited version was misleading and false. After several months of dispute over the story, Wilson and Akre were fired, without the story being broadcast.

  We've known for some time that Fox News is not. (News, that is) This quote is just a great one-sentence underscoring of that fact.

• Nutrition & Health

  Since so many people have asked, here is some of the nutrition information that I have gathered over the years.

  • http://www.thechinastudy.com -- The China Study, a multi-decade research study run by a handful of really smart guys. It is a statistical sampling of an enormous population (over 600,000 individuals) with widely ranging diets and disease rates. Among the findings: animal proteins (e.g., various proteins in meat & eggs and casein found in milk) are shown clearly to enable cancerous growth, while plant proteins disable it. Amazing book. What I want to know is whether the casein in yogurt (i.e., fermented milk) acts the same way as casein in fresh milk ...

  • http://www.newtrendspublishing.com -- A publisher that focuses on health & nutrition ... I have the following books, and I highly recommend them:

    _The_Cholesterol_Myths_ by Uffe Ravnskov -- Your body manufactures way more cholesterol than you can eat in a day. Nobody has managed to show a causative link between eating it and getting heart disease, nor have they shown a causative link between having "high" serum cholesterol and getting heart disease. They are certainly related, but high serum cholesterol is actually an indicator of other causative behaviors (most likely a bad diet, see _The_China_Study_). More importantly, taking cholesterol-reducing medicine is actually way more likely to do you harm than any good.
    -- Note: no longer in print or available on their site ... new edition to appear RSN, via some other publisher

    _Nourishing_Traditions_ by Sally Fallon and Mary Enig -- Fallon seems to be a hippie/revolutionary-wannabe; Enig is a scientist (got her PhD in the study of lipids [dietary fat] at Maryland and is currently one of the world's leading authorities on dietary fat). The parts written by Enig are brilliant; the parts written by Fallon tend toward mud-slinging at the medical establishment (e.g., try to overlook her frequent use of the self-coined term "diet dictocrats"). Whether the medical establishment deserves criticism is not the point; her semi-paranoiac rants threaten to undermine the book's scientific credibility and authority. Oh well. Still an extremely good book -- it is a cookbook, but a very unusual one: the first 70-80 pages present an in-depth treatment of virtually every food out there and how it interacts with your body chemistry and physiology ... instead of saying "X is good, Y is bad" they show you why X is good and Y is bad. Brilliant.

    _The_Untold_Story_of_Milk_ by Ron Schmid, ND -- Interesting, controversial, eye-opening. As far as I can tell, the only real argument for pasteurization of milk is that it allows distributors to take slightly longer to ship it to you (and, of course, then after two weeks it becomes inedible ... instead of souring and becoming arguably more healthy for you).

  • http://www.amazon.com/Pottengers-Cats-Francis-Marion-Pottenger/dp/0916764060 -- The Pottenger's Cats study, showing a link (in cats) between an improper diet and a host of maladies including infertility, physical deformity (e.g. crooked teeth, pinched face), and psychological problems. I have the book and cannot recommend it highly enough. Additionally, here are good articles/essays on the study:

    http://www.ppnf.org/catalog/ppnf/Articles/PottsCats.htm
    http://en.wikipedia.org/wiki/Francis_Pottenger

  • http://www.amazon.com/Nutrition-Physical-Degeneration-Weston-Andrew/dp/0879838167 -- Weston Price's book "Nutrition and Physical Degeneration" ... it is easy to read the Pottenger's Cats study and not be shocked, because your brain does an unconscious buffering of the information to protect you, along the lines of "no worries -- just a study of cats, not humans, no big deal, doesn't apply to me or my kids." The book by Price is a study (observational) of humans, so your brain can't abstract it away. I can only read a few chapters at a time before I have to put it down ... makes a deep impression. Price finds in humans exactly the same issues that Pottenger finds in cats: an undeniable link between diet, specifically the consumption of sugars and processed foods, and a host of maladies including infertility, physical deformity (e.g. crooked teeth, pinched face), and suggested psychological problems.

  • http://www.diabetes-normalsugars.com -- A really interesting and well-written book by a guy who was diagnosed with diabetes in the 1940s and realized that the American medical community was advising him to eat a diet made up primarily of sugar (what bonehead would tell a diabetic to eat tons of something his body can't process?). In particular, read Chapter 9 ... most enlightening: the guy is an engineer as well as a medical doctor and gives a pretty credible argument (backed up with chemical & physiological explanations) that the "four food groups" and "food pyramid" perspectives are both flawed -- that there are actually three main "food groups": carbohydrates, proteins, and fats. Oh, and alcohol.

    http://www.diabetes-normalsugars.com/articles/articles.shtml -- Within that site, a list of related articles ... ones I've read and recommend highly:

    - http://www.diabetes-normalsugars.com/articles/fatlie.shtml -- "What if It's All Been a Big Fat Lie?" by Gary Taubes. New York Times, July 7, 2002
    - http://www.diabetes-normalsugars.com/articles/ssdf.shtml -- "The Soft Science of Dietary Fat," by Gary Taubes. Science, March 3, 2001
    - http://www.diabetes-normalsugars.com/articles/truth_about_fats.shtml -- "The Truth About Fats," by Mary Enig, PhD, and Sally Fallon

    ... that last article is EXTREMELY interesting and a little scary.

  • Information on naturally leavened bread:

    - http://ranprieur.com/readings/natleavbread.html
    - http://www.kensartisan.com/leavenbread.html

    Everyone knows you can't make real beer without fermentation ... well, guess what -- for the same reason, you can't make real pickles using vinegar, and you can't make real bread using commercial yeast.

  • http://www.celticseasalt.com/Celtic_Seasalt_C3.cfm -- The best salt I've ever cooked with ... luckily, my local grocery store carries the stuff. Kept the link around because this is where the first bread article above used to be homed (just realized the link was dead & searched around for another copy of the article). But enough people who eat at our house ask about the salt, figured I'd put the info up.

  Let me know if you find any of the links to be dead ... I already discovered two good sites of nutrition articles and research gone. Such is life.

  Personal observations, in no particular order:

  • Eat lots of good bacteria (present on raw fruits & vegetables ... also present in pickled foods if made right, and in bread if made right).
  • Eat lots of fermented food (has good bacteria, as above, but also makes more of the nutrients available for digestion), including real pickled vegetables (sauerkraut tastes awesome if made right), naturally leavened bread, beer, yogurt, raw cheese, etc. ... though now that I've read The China Study, I have to wonder about yogurt & cheese. Bummer.
  • Eat tons of fruits & vegetables.
  • Stay away from processed foods (refined sugars & grains, etc. ... basically, anything in a box or bag or can these days). And, yes, this includes both breakfast cereal and soft drinks (staples of the student diet).
  • Get good sea salt (no fake iodine).
  • Personally, I'm a fan of real butter on my toast, heavy cream in my coffee, good organic free-range eggs and meats ... but again, I'm re-thinking now that I've read The China Study. Major bummer.

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Best Electric Guitars on the Planet

... not that I'm biased or anything ... :)

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Photo: Marcus Yam, Washington Post
The Chuck Berry of the Engineering World, Susan Kinzie, Washington Post, July 7, 2009. Front page of the Metro section.

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The Gig-Saver: 15 Tones, One Guitar, Interview with Robert Siegel on "All Things Considered," National Public Radio (NPR), July 10, 2009.
Awesome quote from Siegel: "In these hard times, why go buy five new electric guitars when you can buy one?"
You can listen to the audio of the radio segment here:

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"Putting More Sexy In Your Guitar," Bruce Leshan, WUSA TV9, July 8, 2009.

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UMD professor says he's built a better guitar, Maria Zilberman, The Daily Record, July 8, 2009.

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Teaching Tech Transfer Through Music, Erica R. Hendry, The Chronicle of Higher Education, July 27, 2009.

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