109 research outputs found

    Network Interface Design for Network-on-Chip

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    In the culture of globalized integrated circuit (IC, a.k.a chip) production, the use of Intellectual Property (IP) cores, computer aided design tools (CAD) and testing services from un-trusted vendors are prevalent to reduce the time to market. Unfortunately, the globalized business model potentially creates opportunities for hardware tampering and modification from adversary, and this tampering is known as hardware Trojan (HT). Network-on-chip (NoC) has emerged as an efficient on-chip communication infrastructure. In this work, the security aspects of NoC network interface (NI), one of the most critical components in NoC will be investigated and presented. Particularly, the NI design, hardware attack models and countermeasures for NI in a NoC system are explored. An OCP compatible NI is implemented in an IBM0.18ìm CMOS technology. The synthesis results are presented and compared with existing literature. Second, comprehensive hardware attack models targeted for NI are presented from system level to circuit level. The impact of hardware Trojans on NoC functionality and performance are evaluated. Finally, a countermeasure method is proposed to address the hardware attacks in NIs

    Low-Power High-Performance Ternary Content Addressable Memory Circuits

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    Ternary content addressable memories (TCAMs) are hardware-based parallel lookup tables with bit-level masking capability. They are attractive for applications such as packet forwarding and classification in network routers. Despite the attractive features of TCAMs, high power consumption is one of the most critical challenges faced by TCAM designers. This work proposes circuit techniques for reducing TCAM power consumption. The main contribution of this work is divided in two parts: (i) reduction in match line (ML) sensing energy, and (ii) static-power reduction techniques. The ML sensing energy is reduced by employing (i) positive-feedback ML sense amplifiers (MLSAs), (ii) low-capacitance comparison logic, and (iii) low-power ML-segmentation techniques. The positive-feedback MLSAs include both resistive and active feedback to reduce the ML sensing energy. A body-bias technique can further improve the feedback action at the expense of additional area and ML capacitance. The measurement results of the active-feedback MLSA show 50-56% reduction in ML sensing energy. The measurement results of the proposed low-capacitance comparison logic show 25% and 42% reductions in ML sensing energy and time, respectively, which can further be improved by careful layout. The low-power ML-segmentation techniques include dual ML TCAM and charge-shared ML. Simulation results of the dual ML TCAM that connects two sides of the comparison logic to two ML segments for sequential sensing show 43% power savings for a small (4%) trade-off in the search speed. The charge-shared ML scheme achieves power savings by partial recycling of the charge stored in the first ML segment. Chip measurement results show that the charge-shared ML scheme results in 11% and 9% reductions in ML sensing time and energy, respectively, which can be improved to 19-25% by using a digitally controlled charge sharing time-window and a slightly modified MLSA. The static power reduction is achieved by a dual-VDD technique and low-leakage TCAM cells. The dual-VDD technique trades-off the excess noise margin of MLSA for smaller cell leakage by applying a smaller VDD to TCAM cells and a larger VDD to the peripheral circuits. The low-leakage TCAM cells trade off the speed of READ and WRITE operations for smaller cell area and leakage. Finally, design and testing of a complete TCAM chip are presented, and compared with other published designs

    Towards Oxide Electronics:a Roadmap

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    At the end of a rush lasting over half a century, in which CMOS technology has been experiencing a constant and breathtaking increase of device speed and density, Moore's law is approaching the insurmountable barrier given by the ultimate atomic nature of matter. A major challenge for 21st century scientists is finding novel strategies, concepts and materials for replacing silicon-based CMOS semiconductor technologies and guaranteeing a continued and steady technological progress in next decades. Among the materials classes candidate to contribute to this momentous challenge, oxide films and heterostructures are a particularly appealing hunting ground. The vastity, intended in pure chemical terms, of this class of compounds, the complexity of their correlated behaviour, and the wealth of functional properties they display, has already made these systems the subject of choice, worldwide, of a strongly networked, dynamic and interdisciplinary research community. Oxide science and technology has been the target of a wide four-year project, named Towards Oxide-Based Electronics (TO-BE), that has been recently running in Europe and has involved as participants several hundred scientists from 29 EU countries. In this review and perspective paper, published as a final deliverable of the TO-BE Action, the opportunities of oxides as future electronic materials for Information and Communication Technologies ICT and Energy are discussed. The paper is organized as a set of contributions, all selected and ordered as individual building blocks of a wider general scheme. After a brief preface by the editors and an introductory contribution, two sections follow. The first is mainly devoted to providing a perspective on the latest theoretical and experimental methods that are employed to investigate oxides and to produce oxide-based films, heterostructures and devices. In the second, all contributions are dedicated to different specific fields of applications of oxide thin films and heterostructures, in sectors as data storage and computing, optics and plasmonics, magnonics, energy conversion and harvesting, and power electronics

    Cellular Automata

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    Modelling and simulation are disciplines of major importance for science and engineering. There is no science without models, and simulation has nowadays become a very useful tool, sometimes unavoidable, for development of both science and engineering. The main attractive feature of cellular automata is that, in spite of their conceptual simplicity which allows an easiness of implementation for computer simulation, as a detailed and complete mathematical analysis in principle, they are able to exhibit a wide variety of amazingly complex behaviour. This feature of cellular automata has attracted the researchers' attention from a wide variety of divergent fields of the exact disciplines of science and engineering, but also of the social sciences, and sometimes beyond. The collective complex behaviour of numerous systems, which emerge from the interaction of a multitude of simple individuals, is being conveniently modelled and simulated with cellular automata for very different purposes. In this book, a number of innovative applications of cellular automata models in the fields of Quantum Computing, Materials Science, Cryptography and Coding, and Robotics and Image Processing are presented

    Miniaturized Transistors, Volume II

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    In this book, we aim to address the ever-advancing progress in microelectronic device scaling. Complementary Metal-Oxide-Semiconductor (CMOS) devices continue to endure miniaturization, irrespective of the seeming physical limitations, helped by advancing fabrication techniques. We observe that miniaturization does not always refer to the latest technology node for digital transistors. Rather, by applying novel materials and device geometries, a significant reduction in the size of microelectronic devices for a broad set of applications can be achieved. The achievements made in the scaling of devices for applications beyond digital logic (e.g., high power, optoelectronics, and sensors) are taking the forefront in microelectronic miniaturization. Furthermore, all these achievements are assisted by improvements in the simulation and modeling of the involved materials and device structures. In particular, process and device technology computer-aided design (TCAD) has become indispensable in the design cycle of novel devices and technologies. It is our sincere hope that the results provided in this Special Issue prove useful to scientists and engineers who find themselves at the forefront of this rapidly evolving and broadening field. Now, more than ever, it is essential to look for solutions to find the next disrupting technologies which will allow for transistor miniaturization well beyond silicon’s physical limits and the current state-of-the-art. This requires a broad attack, including studies of novel and innovative designs as well as emerging materials which are becoming more application-specific than ever before

    Additive Manufacturing of Conducting Polymers: Recent Advances, Challenges and Opportunities

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    Unformatted postprintConducting polymers (CPs) have been attracting great attention in the development of (bio)electronic devices. Most of current devices are rigid 2D systems and possess uncontrollable geometries and architectures that lead to poor mechanical properties presenting ion/electronic diffusion limitations. The goal of the article is to provide an overview about the additive manufacturing (AM) of conducting polymers, which is of paramount importance for the design of future wearable 3D (bio)electronic devices. Among different 3D printing AM techniques, inkjet, extrusion, electrohydrodynamic and light-based printing have been mainly used. This review article collects examples of 3D printing of conducting polymers such as poly(3,4-ethylene-dioxythiophene) (PEDOT), polypyrrole (PPy) and polyaniline (PANi). It also shows examples of AM of these polymers combined with other polymers and/or conducting fillers such as carbon nanotubes, graphene and silver nanowires. Afterwards, the foremost application of CPs processed by 3D printing techniques in the biomedical and energy fields, i.e., wearable electronics, sensors, soft robotics for human motion, or health monitoring devices, among others, will be discussed.This work was supported by Marie Sklodowska-Curie Research and Innovation Staff Exchanges (RISE) under the grant agreement No 823989 “IONBIKE”. N.A. has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement no. 753293, acronym NanoBEAT

    Solid State Circuits Technologies

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    The evolution of solid-state circuit technology has a long history within a relatively short period of time. This technology has lead to the modern information society that connects us and tools, a large market, and many types of products and applications. The solid-state circuit technology continuously evolves via breakthroughs and improvements every year. This book is devoted to review and present novel approaches for some of the main issues involved in this exciting and vigorous technology. The book is composed of 22 chapters, written by authors coming from 30 different institutions located in 12 different countries throughout the Americas, Asia and Europe. Thus, reflecting the wide international contribution to the book. The broad range of subjects presented in the book offers a general overview of the main issues in modern solid-state circuit technology. Furthermore, the book offers an in depth analysis on specific subjects for specialists. We believe the book is of great scientific and educational value for many readers. I am profoundly indebted to the support provided by all of those involved in the work. First and foremost I would like to acknowledge and thank the authors who worked hard and generously agreed to share their results and knowledge. Second I would like to express my gratitude to the Intech team that invited me to edit the book and give me their full support and a fruitful experience while working together to combine this book

    Development of Electrocatalysts for Oxygen Electrodes in Alkaline Electrochemical Systems

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    In recent years as a larger proportion of our energy needs are being met by renewable energy sources, research and development in energy storage is becoming more significant. Oxygen electrodes, found in electrical energy storage applications such as fuel cells, water electrolysers and metal-air secondary batteries, face the demand for improved performance. In view of this, the research in this thesis focuses on the synthesis and development of oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) catalysts to overcome the slow kinetics of the oxygen electrochemical reactions in alkaline media, followed by the investigation of their combined performance in a tri-electrode zinc-air secondary cell. The ORR performance of various transition metal oxides and carbonaceous materials was initially compared against benchmark catalyst Pt/C using rotating disc electrode measurements. Amorphous MnOx combined with Vulcan XC-72R was found to demonstrate high ORR activity and good stability over the range of cathodic current densities tested. The influence of the synthesis parameters of amorphous MnOx on its ORR activity was subsequently investigated and it was found that optimal amorphous MnOx catalyst can be synthesised with a molar ratio of MnO4-/ Mn2+ of 2.67, by adding KMnO4 to Mn(CH3COO)2 in a basic solution of pH 12 at 295 K. Similarly, the OER performance of transition metal oxides and hydroxides coated on metal mesh was compared and electrodeposited Ni-Fe hydroxide was reported to display high activity and durability when held at anodic potentials. Based on this, various compositions of Ni-based binary and Ni-Fe based ternary metal hydroxides were screened with a unique microelectrode set-up at high current densities up to 1 A cm-2. Ni-Fe-Co hydroxide showed most improved OER performance. The effect of electrodeposition parameters on the electrocatalytic performance of Ni-Fe-Co hydroxide were examined and used to further optimise the catalyst. Ni-Fe-Co hydroxide cathodically deposited at 300 mA cm-2 for 240 s at 22 ºC, pH 3.9 was found to demonstrate best OER performance, giving an overpotential of 235 mV at 0.1 A cm-2. The electrodes with optimised catalysts were tested in an in-house built zinc-air cycling set-up, demonstrating energy efficiencies of 58-61% up to 40 h at 20 mA cm-2 in 4 M NaOH + 0.3 M ZnO at 333 K

    Science and technology roadmap for graphene, related two-dimensional crystals, and hybrid systems

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    We present the science and technology roadmap for graphene, related two-dimensional crystals, and hybrid systems, targeting an evolution in technology, that might lead to impacts and benefits reaching into most areas of society. This roadmap was developed within the framework of the European Graphene Flagship and outlines the main targets and research areas as best understood at the start of this ambitious project. We provide an overview of the key aspects of graphene and related materials (GRMs), ranging from fundamental research challenges to a variety of applications in a large number of sectors, highlighting the steps necessary to take GRMs from a state of raw potential to a point where they might revolutionize multiple industries. We also define an extensive list of acronyms in an effort to standardize the nomenclature in this emerging field.Peer ReviewedPostprint (published version

    Low Power Memory/Memristor Devices and Systems

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    This reprint focusses on achieving low-power computation using memristive devices. The topic was designed as a convenient reference point: it contains a mix of techniques starting from the fundamental manufacturing of memristive devices all the way to applications such as physically unclonable functions, and also covers perspectives on, e.g., in-memory computing, which is inextricably linked with emerging memory devices such as memristors. Finally, the reprint contains a few articles representing how other communities (from typical CMOS design to photonics) are fighting on their own fronts in the quest towards low-power computation, as a comparison with the memristor literature. We hope that readers will enjoy discovering the articles within
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