AND gate

About: AND gate is a research topic. Over the lifetime, 11860 publications have been published within this topic receiving 109726 citations.

The TFT A New Thin-Film Transistor

Abstract: A thin-film transistor, TFT, fabricated by evaporation of all components on to an insulating substrate has been developed. Operation is based upon the control of injected majority carriers in a wide-band-gap semiconductor by means of an insulated control gate. Experimental units using microcrystalline layers of cadmium sulfide have yielded voltage amplification factors greater than 100, transconductances greater than 10,000 , ?mho, input impedances greater than 106 ? shunted by 50 pf and gain-bandwidth products greater than 10 Mc. Switching speeds of less than 0.1 ?sec have been observed. Simple evaporated thin-film circuits incorporating the TFT have been built. Direct coupling between stages is permitted since the insulated gate electrode can be biased positively as well as negatively without drawing appreciable gate current. Modified forms of the TFT have been built for use as a flip-flop, an AND gate and a NOR gate in computer applications.

HotLeakage: A Temperature-Aware Model of Subthreshold and Gate Leakage for Architects

Abstract: This report introduces HotLeakage, an architectural model for subthreshold and gate leakage that we have developed here at the University of Virginia. The most important features of HotLeakage are the explicit inclusion of temperature, voltage, gate leakage, and parameter variations, and the ability to recalculate leakage currents dynamically as temperature and voltage change due to operating conditions, DVS techniques, etc. HotLeakage provides default settings for 180nm through 70nm technologies for modeling cache and register files, and provides a simple interface for selecting alternate parameter values and for modeling alternative microarchitecture structures. It also provides models for several extant cache leakage control techniques, with an interface for adding further techniques. HotLeakage is currently a semi-independent module for use with SimpleScalar, but is sufficiently modular that it should be fairly easy to port to other simulators. Because sub-threshold leakage currents are exponentially dependent on temperature and voltage, because gate leakage is growing so rapidly, and because parameter variations can have a profound effect on simulation accuracy, we hope that HotLeakage will serve as a useful tool for microarchitects to more accurately evaluate issues related leakage power. HotLeakage is available for download athttp://lava.cs.virginia.edu/HotLeakage

Easily Testable Realizations ror Logic Functions

Abstract: Desirable properties of "easily testable networks" are given. A realization for arbitrary logic function, using AND and EXCLUSIVE-OR gates, based on Reed-Muller canonic expansion is given that has many of these desirable properties. If only permanent stuck-at-0 (s-a-0) or stuck-at-1 (s-a-1) faults occur in a single AND gate or only a single EXCLUSIVE-OR gate is faulty, the following results are derived on fault detecting test sets for the proposed networks: 1) only (n/4) tests, independent of the function being realized, are required if the primary inputs are fault-free; 2) only 2n, additional inputs (which depend on the function realized) are required if the primary inputs can be faulty, where n, is the number of variables appearing in even number of product terms in the Reed-Muller canonical expansion of the function; and 3) the additional 2ne inputs are not required if the network is provided with an observable point at the output of an extra AND gate.

All-photonic multifunctional molecular logic device.

Abstract: Photochromes are photoswitchable, bistable chromophores which, like transistors, can implement binary logic operations. When several photochromes are combined in one molecule, interactions between them such as energy and electron transfer allow design of simple Boolean logic gates and more complex logic devices with all-photonic inputs and outputs. Selective isomerization of individual photochromes can be achieved using light of different wavelengths, and logic outputs can employ absorption and emission properties at different wavelengths, thus allowing a single molecular species to perform several different functions, even simultaneously. Here, we report a molecule consisting of three linked photochromes that can be configured as AND, XOR, INH, half-adder, half-subtractor, multiplexer, demultiplexer, encoder, decoder, keypad lock, and logically reversible transfer gate logic devices, all with a common initial state. The system demonstrates the advantages of light-responsive molecules as multifunctional, reconfigurable nanoscale logic devices that represent an approach to true molecular information processing units.

The interpretation and application of Rent's rule

Abstract: This paper provides a review of both Rent's rule and the placement models derived from it. It is proposed that the power-law form of Rent's rule, which predicts the number of terminals required by a group of gates for communication with the rest of the circuit, is a consequence of a statistically homogeneous circuit topology and gate placement. The term "homogeneous" is used to imply that quantities such as the average wire length per gate and the average number of terminals per gate are independent of the position within the circuit. Rent's rule is used to derive a variety of net length distribution models and the approach adopted in this paper is to factor the distribution function into the product of an occupancy probability distribution and a function which represents the number of valid net placement sites. This approach places diverse placement models under a common framework and allows the errors introduced by the modeling process to be isolated and evaluated. Models for both planar and hierarchical gate placement are presented.