The XScale Experience: Combining High Performance with Low Power on 0.18um through 90 nm Technologies

The StrongARM raised the bar for embedded microprocessor performance and power dissipation. This talk traces our efforts to follow and expand upon that legacy through designs on three process generations in what came to be named the XScale series of microprocessors. After reviewing the StrongARM, the discussion will focus on efforts to make an ARM compatible microprocessor having improved performance and power/performance on a 0.18 .m technology generation. The development of leakage suppressing .Drowsy. modes and inclusion of active power saving features such as hierarchical clock gating and pulse-clocked latches, as well as other features will be discussed. Efforts on 130 nm will be briefly described. The talk will then move on to the development effort for the 90 nm versions, which had to support two different processes. Emphasis will be on the tradeoffs between manpower, technical risk, and time to market vs. what is required to really beat the competition. Discussion will also cover technologies for leakage mitigation in sub 100 nm processes as well as active performance and power tradeoffs, primarily in memories and other full-custom circuits.
Lawrence T. Clark was born in Detroit, Michigan. He graduated with a B.S. in computer science from Northern Arizona University and received his M.S. and Ph.D. in electrical engineering from Arizona State University. Dr. Clark has over 15 years of industry experience at VLSI Technology Inc. and Intel Corp. in various capacities including chipset and microprocessor design, CMOS imager research, and compact device modeling. While at Intel, he contributed to the Pentium, Itanium, and XScale microprocessor designs. Most recently, he was a principal engineer and circuit design manager for Intel XScale microprocessors. He is presently an associate professor of electrical engineering at Arizona State University. For the 2003-2004 academic year he was an associate professor of electrical and computer engineering at the University of New Mexico. Dr. Clark has been awarded about 50 patents on VLSI circuits and architectures and has approximately 15 pending.