V. Kamakoti

Bio: V. Kamakoti is an academic researcher from Indian Institute of Technology Madras. The author has contributed to research in topics: Field-programmable gate array & Benchmark (computing). The author has an hindex of 17, co-authored 121 publications receiving 901 citations. Previous affiliations of V. Kamakoti include National Institute of Technology, Tiruchirappalli & Indian Institute of Science.

A universal random test generator for functional verification of microprocessors and system-on-chip

Abstract: This paper presents a universal random test generator template for the design verification of microprocessors and system-on-chips (SOCs). The tool enables verification of the product in one continuous, integrated environment, from C model to behavioral RTL and gate to system-level integration, all in one self-contained chassis. Due to complexity of large designs, it has been a common practice to rely on the power of randomization, to bless us with the humanly not-conceivable corner cases that can arise in reality. There are lots of common features shared by random tools used for testing products with diverse functionalities. This paper proposes a template which captures the commonalities among the different random testing tools and enables the user to quickly design a random test generator by adding product-specific details and using most of the methods available in the template. This leads to high degree of code reuse, less debugging of the random tool and huge reduction in design-cycle time. In addition the template provides enough flexibility and interfaces to enable the execution of the generated tests on targets which may be a C model, RTL or the final chip. By this, one may test a software component, say a bootup code for the system-on-chip or microprocessor at all stages of its design, namely, the software prototype, the RTL at the pre-silicon level and finally the chip, at a post-silicon level. This satisfies the expectations out of a verification platform for a hardware-software codesign environment. The random test generator template was employed for testing a x86-compatible microprocessor both at RTL and post-silicon stage and a software model of a 802.11 MAC. The results are presented in the paper.

PERI: A Configurable Posit Enabled RISC-V Core

Abstract: Owing to the failure of Dennard’s scaling, the past decade has seen a steep growth of prominent new paradigms leveraging opportunities in computer architecture. Two technologies of interest are Posit and RISC-V. Posit was introduced in mid-2017 as a viable alternative to IEEE-754, and RISC-V provides a commercial-grade open source Instruction Set Architecture (ISA). In this article, we bring these two technologies together and propose a Configurable Posit Enabled RISC-V Core called PERI. The article provides insights on how the Single-Precision Floating Point (“F”) extension of RISC-V can be leveraged to support posit arithmetic. We also present the implementation details of a parameterized and feature-complete posit Floating Point Unit (FPU). The configurability and the parameterization features of this unit generate optimal hardware, which caters to the accuracy and energy/area tradeoffs imposed by the applications, a feature not possible with IEEE-754 implementation. The posit FPU has been integrated with the RISC-V compliant SHAKTI C-class core as an execution unit. To further leverage the potential of posit, we enhance our posit FPU to support two different exponent sizes (with posit-size being 32-bits), thereby enabling multiple-precision at runtime. To enable the compilation and execution of C programs on PERI, we have made minimal modifications to the GNU C Compiler (GCC), targeting the “F” extension of the RISC-V. We compare posit with IEEE-754 in terms of hardware area, application accuracy, and runtime. We also present an alternate methodology of integrating the posit FPU with the RISC-V core as an accelerator using the custom opcode space of RISC-V.

A principal component neural network-based face recognition system and ASIC implementation

Abstract: Principal component analysis (PCA) finds wide usage in computer-aided vision applications and one such application is face recognition. The neural network that performs PCA is called a principal component neural network (PCNN). This paper presents a new PCNN-based face recognition system. The proposed recognition system can tolerate local variations in the face such as expression changes and directional lighting. An optimal digital hardware design is proposed for PCNN. An ASIC implementation of the proposed design yields a throughput of processing about 11,000 inputs per second during the training phase and about 19,000 inputs per second during the retrieval phase. The customized hardware-based recognition is about 10/sup 5/ times faster than a software-based recognition in a PC. Such results are valuable for high-speed applications.

DFT Assisted Techniques for Peak Launch-to-Capture Power Reduction during Launch-On-Shift At-Speed Testing

Abstract: Scan-based testing is crucial to ensuring correct functioning of chips. In this scheme, the scan and capture phases are interleaved. It is well known that for large designs, excessive switching activity during the launch-to-capture window leads to high voltage droop on the power grid, ultimately resulting in false delay failures during at-speed test. This article proposes a new design-for-testability (DFT) scheme for launch-on-shift (LOS) testing, which ensures that the combinational logic remains undisturbed between the interleaved capture phases, providing computer-aided-design (CAD) tools with extra search space for minimizing launch-to-capture switching activity through test pattern ordering (TPO). We further propose a new TPO algorithm that keeps track of the don't cares during the ordering process, so that the don't care filling step after the ordering process yields a better reduction in launch-to-capture switching activity compared to any other technique in the literature. The proposed DFT-assisted technique, when applied to circuits in ITC99 benchmark suite, produces an average reduction of 17.68p in peak launch-to-capture switching activity (CSA) compared to the best known lowpower TPO technique. Even for circuits whose test cubes are not rich in don't care bits, the proposed technique produces an average reduction of 15p in peak CSA, while for the circuits with test cubes rich in don't care bits (≥75p), the average reduction is 24p. The proposed technique also reduces the average power dissipation (considering both scan cells and combinational logic) during the scan phase by about 43.5p on an average, compared to the adjacent filling technique.

I and i

Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

A Survey of Face Recognition Techniques

Abstract: Face recognition presents a challenging problem in the field of image analysis and computer vision, and as such has received a great deal of attention over the last few years because of its many applications in various domains. Face recognition techniques can be broadly divided into three categories based on the face data acquisition methodology: methods that operate on intensity images; those that deal with video sequences; and those that require other sensory data such as 3D information or infra-red imagery. In this paper, an overview of some of the well-known methods in each of these categories is provided and some of the benefits and drawbacks of the schemes mentioned therein are examined. Furthermore, a discussion outlining the incentive for using face recognition, the applications of this technology, and some of the difficulties plaguing current systems with regard to this task has also been provided. This paper also mentions some of the most recent algorithms developed for this purpose and attempts to give an idea of the state of the art of face recognition technology.

Parallel CAD: Algorithm Design and Programming Special Section Call for Papers TODAES: ACM Transactions on Design Automation of Electronic Systems

Abstract: High-performance parallel computer architecture and systems have been improved at a phenomenal rate. In the meantime, VLSI computer-aided design (CAD) software for multibillion-transistor IC design has become increasingly complex and requires prohibitively high computational resources. Recent studies have shown that, numerous CAD problems, with their high computational complexity, can greatly benefit from the fast-increasing parallel computation capabilities. However, parallel programming imposes big challenges for CAD applications. Fully exploiting the computational power of emerging general-purpose and domain-specific multicore/many-core processor systems, calls for fundamental research and engineering practice across every stage of parallel CAD design, from algorithm exploration, programming models, design-time and run-time environment, to CAD applications, such as verification, optimization, and simulation. This journal special section will cover recent progress on parallel CAD research, including algorithm foundations, programming models, parallel architectural-specific optimization, and verification. More specifically, papers with in-depth and extensive coverage of the following topics will be considered, as well as other topics relevant to the design of parallel CAD algorithms and software tools. 1. Parallel algorithm design and specification for CAD applications 2. Parallel programming models and languages of particular use in CAD 3. Runtime support and performance optimization for CAD applications 4. Parallel architecture-specific design and optimization for CAD applications 5. Parallel program debugging and verification techniques particularly relevant for CAD The papers should be submitted via the Manuscript Central website and should adhere to standard ACM TODAES formatting requirements (http://todaes.acm.org/). The page count limit is 25.

On-Chip Communication Architectures: System on Chip Interconnect

Abstract: Over the past decade, system-on-chip (SoC) designs have evolved to address the ever increasing complexity of applications, fueled by the era of digital convergence. Improvements in process technology have effectively shrunk board-level components so they can be integrated on a single chip. New on-chip communication architectures have been designed to support all inter-component communication in a SoC design. These communication architecture fabrics have a critical impact on the power consumption, performance, cost and design cycle time of modern SoC designs. As application complexity strains the communication backbone of SoC designs, academic and industrial R&D efforts and dollars are increasingly focused on communication architecture design. This book is a comprehensive reference on concepts, research and trends in on-chip communication architecture design. It will provide readers with a comprehensive survey, not available elsewhere, of all current standards for on-chip communication architectures. KEY FEATURES * A definitive guide to on-chip communication architectures, explaining key concepts, surveying research efforts and predicting future trends * Detailed analysis of all popular standards for on-chip communication architectures * Comprehensive survey of all research on communication architectures, covering a wide range of topics relevant to this area, spanning the past several years, and up to date with the most current research efforts * Future trends that with have a significant impact on research and design of communication architectures over the next several years