Configurable multiple value encoders using semi floating-gate

This thesis presents a new multiple-valued encoder with re-configurable radix. The proposed circuits utilize serial cyclic D/A conversion and semi floatinggate (SFG) inverters for compact design and a high functional capacity per device. A re-configurable radix is not supported by existing SFG inverter based multiple-valued encoders which make use of parallel binary weight D/A conversion. The study covers least significant bit-first (LSB), least significant bit-first with alternate bit inversion (LSB ABI) and most significant bit-first (MSB) digital input codes. The serial cyclic D/A converters with LSB and LSB ABI input codes are implemented in a double-poly 0.35um AMS process. Measured results are provided and analyzed using standard static D/A converter performance measures. Circuits are tested using the practical radices 4, 8 and 16. Experimental results demonstrate that serial cyclic D/A converters using SFG inverters are feasible. Compared to related work on cyclic D/A conversion, the proposed circuits feature both a reduced number of devices and a reduction in the required die area. Several new techniques are identified for extending the resolution beyond radix 4, 8 and 16 MVL applications. This includes an error correction algorithm called least significant bit-first with alternate bit inversion (LSB ABI), a sample and hold clock scheme and a Dual Data-Rate (DDR) mode of D/A converter operation. The techniques are implemented on a chip and measured results are provided. The thesis also includes simulation work on several new SFG based circuits. A ternary serial D/A converter, a MSB-first serial D/A converter and a multiple-valued frequency divider which features re-configurable modulus

An Optimal Gate Design for the Synthesis of Ternary Logic Circuits

Department of Electrical EngineeringOver the last few decades, CMOS-based digital circuits have been steadily developed. However, because of the power density limits, device scaling may soon come to an end, and new approaches for circuit designs are required. Multi-valued logic (MVL) is one of the new approaches, which increases the radix for computation to lower the complexity of the circuit. For the MVL implementation, ternary logic circuit designs have been proposed previously, though they could not show advantages over binary logic, because of unoptimized synthesis techniques. In this thesis, we propose a methodology to design ternary gates by modeling pull-up and pull-down operations of the gates. Our proposed methodology makes it possible to synthesize ternary gates with a minimum number of transistors. From HSPICE simulation results, our ternary designs show significant power-delay product reductions; 49 % in the ternary full adder and 62 % in the ternary multiplier compared to the existing methodology. We have also compared the number of transistors in CMOS-based binary logic circuits and ternary device-based logic circuits We propose a methodology for using ternary values effectively in sequential logic. Proposed ternary D flip-flop is designed to normally operate in four-edges of a ternary clock signal. A quad-edge-triggered ternary D flip-flop (QETDFF) is designed with static gates using CNTFET. From HSPICE simulation results, we have confirmed that power-delay-product (PDP) of QETDFF is reduced by 82.31 % compared to state of the art ternary D flip-flop. We synthesize a ternary serial adder using QETDFF. PDP of the proposed ternary serial adder is reduced by 98.23 % compared to state of the art design.ope

Miniaturized Transistors, Volume II

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

A study of multiplex data bus techniques for the space shuttle

A comprehensive technology base for the design of a multiplexed data bus subsystem is provided. Extensive analyses, both analytical and empirical, were performed. Subjects covered are classified under the following headings: requirements identification and analysis; transmission media studies; signal design and detection studies; synchronization, timing, and control studies; user-subsystem interface studies; operational reliability analyses; design of candidate data bus configurations; and evaluation of candidate data bus designs

NASA Tech Briefs, Spring 1977

Topics: NASA TU Services: Technology Utilization services that can assist you in learning about and applying NASA technology; New Product Ideas: A summary of sel~ted innovations of value to manufacturers for the development of new products; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Life Sciences; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences

Cumulative index to NASA Tech Briefs, 1970-1975

Tech briefs of technology derived from the research and development activities of the National Aeronautics and Space Administration are presented. Abstracts and indexes of subject, personal author, originating center, and tech brief number for the 1970-1975 tech briefs are presented

Maritime expressions:a corpus based exploration of maritime metaphors

This study uses a purpose-built corpus to explore the linguistic legacy of Britain’s maritime history found in the form of hundreds of specialised ‘Maritime Expressions’ (MEs), such as TAKEN ABACK, ANCHOR and ALOOF, that permeate modern English. Selecting just those expressions commencing with ’A’, it analyses 61 MEs in detail and describes the processes by which these technical expressions, from a highly specialised occupational discourse community, have made their way into modern English. The Maritime Text Corpus (MTC) comprises 8.8 million words, encompassing a range of text types and registers, selected to provide a cross-section of ‘maritime’ writing. It is analysed using WordSmith analytical software (Scott, 2010), with the 100 million-word British National Corpus (BNC) as a reference corpus. Using the MTC, a list of keywords of specific salience within the maritime discourse has been compiled and, using frequency data, concordances and collocations, these MEs are described in detail and their use and form in the MTC and the BNC is compared. The study examines the transformation from ME to figurative use in the general discourse, in terms of form and metaphoricity. MEs are classified according to their metaphorical strength and their transference from maritime usage into new registers and domains such as those of business, politics, sports and reportage etc. A revised model of metaphoricity is developed and a new category of figurative expression, the ‘resonator’, is proposed. Additionally, developing the work of Lakov and Johnson, Kovesces and others on Conceptual Metaphor Theory (CMT), a number of Maritime Conceptual Metaphors are identified and their cultural significance is discussed