David Roberts

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In this paper, we present a dynamic voltage scaling (DVS) technique called Razor which incorporates an in situ error detection and correction mechanism to recover from timing errors. We also present the implementation details and silicon measurements results of a 64-bit processor fabricated in 0.18-/spl mu/m technology that uses Razor for supply voltage(More)
Flash is a widely used storage device that provides high density and low power, appealing properties for general purpose computing. Today, its usual application is in portable special purpose devices such as MP3 players. In this paper we examine its use in the server domain—a more general purpose environment. Aggressive process scaling and the use of(More)
Die-stacked DRAM is a technology that will soon be integrated in high-performance systems. Recent studies have focused on hardware caching techniques to make use of the stacked memory, but these approaches require complex changes to the processor and also cannot leverage the stacked memory to increase the system's overall memory capacity. In this work, we(More)
One of today's most successful embedded devices, the mobile phone, embodies a set of challenging design requirements: long battery life, small size, high performance and low cost. The single parameter that complicates the simultaneous fulfilment of all of these design goals is energy efficiency of the system, since batteries only hold a finite amount of(More)
In this article, we discuss experiences and lessons learned from deploying four mobile sensing applications on off-the-shelf mobile phones within a recreational framework called MobSens that contains elements of health, social, and environmental sensing at both individual and community levels. We describe the main components of our applications, which(More)
In this study, we investigate different cache fault tolerance techniques to determine which will be most effective when on-chip memory cell defect probabilities exceed those of current technologies, which is highly anticipated in processor on-chip caches manufactured with future nanometer scale technologies. Our most significant finding from this study is(More)
Recent breakthroughs in circuit and process technology have enabled new usage models for non-volatile memory technologies such as Flash and phase change RAM (PCRAM) in the general purpose computing environment. These technologies display high density and low power consumption as well as persistency that are appealing properties in a memory device. This(More)
DRAM technology faces density and power challenges to increase capacity because of limitations of physical cell design. To overcome these limitations, system designers are exploring alternative solutions that combine DRAM and emerging NVRAM technologies. Previous work on heterogeneous memories focuses, mainly, on two system designs: PCache, a hierarchical,(More)
The emergence of die-stacking technology with mixed logic and memory processes has brought about a renaissance in “processing in memory” (PIM) concepts, first envisioned decades ago. For some, the PIM concept conjures an image of a complete processing unit (e.g., CPU, GPU) integrated directly with memory, perhaps on a logic chip 3D-stacked under one or more(More)
By comparing two-dimensional (2D) chemical animations designed for computer’s desktop with three-dimensional (3D) chemical animations designed for the full immersive virtual reality environment CAVE we studied how virtual reality environments could raise student’s interest and motivation for learning. By using the 3ds max, we can visualize the chemical(More)