1,188 research outputs found
Temperature Regulation in Multicore Processors Using Adjustable-Gain Integral Controllers
This paper considers the problem of temperature regulation in multicore
processors by dynamic voltage-frequency scaling. We propose a feedback law that
is based on an integral controller with adjustable gain, designed for fast
tracking convergence in the face of model uncertainties, time-varying plants,
and tight computing-timing constraints. Moreover, unlike prior works we
consider a nonlinear, time-varying plant model that trades off precision for
simple and efficient on-line computations. Cycle-level, full system simulator
implementation and evaluation illustrates fast and accurate tracking of given
temperature reference values, and compares favorably with fixed-gain
controllers.Comment: 8 pages, 6 figures, IEEE Conference on Control Applications 2015,
Accepted Versio
A Survey of Techniques For Improving Energy Efficiency in Embedded Computing Systems
Recent technological advances have greatly improved the performance and
features of embedded systems. With the number of just mobile devices now
reaching nearly equal to the population of earth, embedded systems have truly
become ubiquitous. These trends, however, have also made the task of managing
their power consumption extremely challenging. In recent years, several
techniques have been proposed to address this issue. In this paper, we survey
the techniques for managing power consumption of embedded systems. We discuss
the need of power management and provide a classification of the techniques on
several important parameters to highlight their similarities and differences.
This paper is intended to help the researchers and application-developers in
gaining insights into the working of power management techniques and designing
even more efficient high-performance embedded systems of tomorrow
Performance Regulation and Tracking via Lookahead Simulation: Preliminary Results and Validation
This paper presents an approach to target tracking that is based on a
variable-gain integrator and the Newton-Raphson method for finding zeros of a
function. Its underscoring idea is the determination of the feedback law by
measurements of the system's output and estimation of its future state via
lookahead simulation. The resulting feedback law is generally nonlinear. We
first apply the proposed approach to tracking a constant reference by the
output of nonlinear memoryless plants. Then we extend it in a number of
directions, including the tracking of time-varying reference signals by
dynamic, possibly unstable systems. The approach is new hence its analysis is
preliminary, and theoretical results are derived for nonlinear memoryless
plants and linear dynamic plants. However, the setting for the controller does
not require the plant-system to be either linear or stable, and this is
verified by simulation of an inverted pendulum tracking a time-varying signal.
We also demonstrate results of laboratory experiments of controlling a platoon
of mobile robots.Comment: A modified version will appear in Proc. 56th IEEE Conf. on Decision
and Control, 201
Per-Core DVFS with Switched-Capacitor Converters for Energy Efficiency in Manycore Processors
Integrating multiple power converters on-chip improves energy efficiency of manycore architectures. Switched-capacitor (SC) dc-dc converters are compatible with conventional CMOS processes, but traditional implementations suffer from limited conversion efficiency. We propose a dynamic voltage and frequency scaling scheme with SC converters that achieves high converter efficiency by allowing the output voltage to ripple and having the processor core frequency track the ripple. Minimum core energy is achieved by hopping between different converter modes and tuning body-bias voltages. A multicore processor model based on a 28-nm technology shows conversion efficiencies of 90% along with over 25% improvement in the overall chip energy efficiency
A survey of techniques for reducing interference in real-time applications on multicore platforms
This survey reviews the scientific literature on techniques for reducing interference in real-time multicore systems, focusing on the approaches proposed between 2015 and 2020. It also presents proposals that use interference reduction techniques without considering the predictability issue. The survey highlights interference sources and categorizes proposals from the perspective of the shared resource. It covers techniques for reducing contentions in main memory, cache memory, a memory bus, and the integration of interference effects into schedulability analysis. Every section contains an overview of each proposal and an assessment of its advantages and disadvantages.This work was supported in part by the Comunidad de Madrid Government "Nuevas Técnicas de Desarrollo de Software de Tiempo Real Embarcado Para Plataformas. MPSoC de Próxima Generación" under Grant IND2019/TIC-17261
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