Realization of the conventional Von Neumann architecture faces increasing challenges due to growing process variations, device reliability and power consumption. As an appealing architectural solution, brain-inspired neuromorphic computing has drawn a great deal of research interest due to its potential improved scalability and power efficiency, and better suitability in processing complex tasks. Moreover, inherit error resilience in neuromorphic computing allows remarkable power and energy savings by exploiting approximate computing. This dissertation focuses on a scalable and energy efficient neurocomputing architecture which leverages emerging memristor nanodevices and a novel approximate arithmetic for cognitive computing. First, brain-inspired digital neuromorphic processor (DNP) architecture with memristive synaptic crossbar is presented for large scale spiking neural networks. We leverage memristor nanodevices to build an N x N crossbar array to store not only multibit synaptic weight values but also the network configuration data with significantly reduced area cost. Additionally, the crossbar array is accessible both column- and row-wise to significantly expedite the synaptic weight update process for on-chip learning. The proposed digital pulse width modulator (PWM) readily creates a binary pulse with various durations to read and write the multilevel memristors with low cost. Our design integrates N digital leaky integrate-and-fire (LIF) silicon neurons to mimic their biological counterparts and the respective on-chip learning circuits for implementing spike timing dependent plasticity (STDP) learning rules. The proposed column based analog-to-digital conversion (ADC) scheme accumulates the pre-synaptic weights of a neuron efficiently and reduces silicon area by using only one shared arithmetic unit for processing LIF operations of all N neurons. With 256 silicon neurons, the learning circuits and 64K synapses, the power dissipation and area of our design are evaluated as 6.45 mW and 1.86 mm2, respectively, in a 90 nm CMOS technology. Furthermore, arithmetic computations contribute significantly to the overall processing time and power of the proposed architecture. In particular, addition and comparison operations represent 88.5% and 42.9% of processing time and power for digital LIF computation, respectively. Hence, by exploiting the built-in resilience of the presented neuromorphic architecture, we propose novel approximate adder and comparator designs to significantly reduce energy consumption with a very low error rate. The significantly improved error rate and critical path delay stem from a novel carry prediction technique that leverages the information from less significant input bits in a parallel manner. An error magnitude reduction scheme is proposed to further reduce amount of error once detected with low cost in the proposed adder design. Implemented in a commercial 90 nm CMOS process, it is shown that the proposed adder is up to 2.4x faster and 43% more energy efficient over traditional adders while having an error rate of only 0.18%. Additionally, the proposed comparator achieves an error rate of less than 0.1% and an energy reduction of up to 4.9x compared to the conventional ones. The proposed arithmetic has been adopted in a VLSI-based neuromorphic character recognition chip using unsupervised learning. The approximation errors of the proposed arithmetic units have been shown to have negligible impacts on the training process. Moreover, the energy saving of up to 66.5% over traditional arithmetic units is achieved for the neuromorphic chip with scaled supply levels. The electronic version of this dissertation is accessible from http://hdl.handle.net/1969.1/151721

This book gathers selected high-quality research papers presented at International Conference on Paradigms of Communication, Computing and Data Sciences (PCCDS 2022), held at Malaviya National Institute of Technology Jaipur, India, during 05 – 07 July 2022. It discusses high-quality and cutting-edge research in the areas of advanced computing, communications and data science techniques. The book is a collection of latest research articles in computation algorithm, communication and data sciences, intertwined with each other for efficiency.

This book provides readers with a comprehensive, state-of-the-art overview of approximate computing, enabling the design trade-off of accuracy for achieving better power/performance efficiencies, through the simplification of underlying computing resources. The authors describe in detail various efforts to generate approximate hardware systems, while still providing an overview of support techniques at other computing layers. The book is organized by techniques for various hardware components, from basic building blocks to general circuits and systems.

This book provides readers with an up-to-date account of the use of machine learning frameworks, methodologies, algorithms and techniques in the context of computer-aided design (CAD) for very-large-scale integrated circuits (VLSI). Coverage includes the various machine learning methods used in lithography, physical design, yield prediction, post-silicon performance analysis, reliability and failure analysis, power and thermal analysis, analog design, logic synthesis, verification, and neuromorphic design. Provides up-to-date information on machine learning in VLSI CAD for device modeling, layout verifications, yield prediction, post-silicon validation, and reliability; Discusses the use of machine learning techniques in the context of analog and digital synthesis; Demonstrates how to formulate VLSI CAD objectives as machine learning problems and provides a comprehensive treatment of their efficient solutions; Discusses the tradeoff between the cost of collecting data and prediction accuracy and provides a methodology for using prior data to reduce cost of data collection in the design, testing and validation of both analog and digital VLSI designs. From the Foreword As the semiconductor industry embraces the rising swell of cognitive systems and edge intelligence, this book could serve as a harbinger and example of the osmosis that will exist between our cognitive structures and methods, on the one hand, and the hardware architectures and technologies that will support them, on the other....As we transition from the computing era to the cognitive one, it behooves us to remember the success story of VLSI CAD and to earnestly seek the help of the invisible hand so that our future cognitive systems are used to design more powerful cognitive systems. This book is very much aligned with this on-going transition from computing to cognition, and it is with deep pleasure that I recommend it to all those who are actively engaged in this exciting transformation. Dr. Ruchir Puri, IBM Fellow, IBM Watson CTO & Chief Architect, IBM T. J. Watson Research Center

This book serves as a single-source reference to the latest advances in Approximate Computing (AxC), a promising technique for increasing performance or reducing the cost and power consumption of a computing system. The authors discuss the different AxC design and validation techniques, and their integration. They also describe real AxC applications, spanning from mobile to high performance computing and also safety-critical applications.

This book explores the technological developments at various levels of abstraction, of the new paradigm of approximate computing. The authors describe in a single-source the state-of-the-art, covering the entire spectrum of research activities in approximate computing, bridging device, circuit, architecture, and system levels. Content includes tutorials, reviews and surveys of current theoretical/experimental results, design methodologies and applications developed in approximate computing for a wide scope of readership and specialists. Serves as a single-source reference to state-of-the-art of approximate computing; Covers broad range of topics, from circuits to applications; Includes contributions by leading researchers, from academia and industry.

This book comprises select papers from the international conference on Research in Intelligent and Computing in Engineering (RICE 2019) held at Hanoi University of Industry, Hanoi, Vietnam. The volume focuses on current research on various computing models such as centralized, distributed, cluster, grid and cloud. The contents cover recent advances in wireless sensor networks, mobile ad hoc networks, internet of things, machine learning, grid and cloud computing, and their various applications. The book will help researchers as well as professionals to gain insight into the rapidly evolving fields of internet computing and data mining.