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Digital theory, logic, and two-state control
Published in Raymond F. Gardner, Introduction to Plant Automation and Controls, 2020
Whereas combinational logic uses discrete condition-based input signals, sequential logic follows a series of events, and to function, it requires memory of its previous output. Sequential logic can be event driven, clock driven, or pulse driven. Figure 4.9shows a general functional block diagram of sequential logic. Event-driven sequential logic uses an external signal, such as a hand- or pressure-actuated switch, to change the output logic state when toggled, and is called asynchronous since it is independent of a clock.Clock-driven sequential logic is synchronized to a clock, which obtains its triggering function from a timer circuit.Pulse-driven sequential logic uses both event- and clock-driven triggering inputs. The toggling that would normally happen with an input-signal switch must occur simultaneously with a clock-driven signal obtained from a timer circuit. When both the input signal and clock signal occur, the output logic state can be triggered to a new state.
Introduction
Published in Vlad P. Shmerko, Svetlana N. Yanushkevich, Sergey Edward Lyshevski, Computer Arithmetics for Nanoelectronics, 2018
Vlad P. Shmerko, Svetlana N. Yanushkevich, Sergey Edward Lyshevski
Latches and flip-flops are the basic building blocks of sequential logic networks. Latches provide a mechanism for the simplest control of the storage of one bit: 1bit memory⏟Physical phenomenonDesign⏟Latch1bit memory control⏟Len
CMOS Circuits
Published in Vojin G. Oklobdzija, Digital Design and Fabrication, 2017
Eugene John, Shunzo Yamashita, Dejan Marković, Yuichi Kado
Complementary metal oxide semiconductor (CMOS) VLSI logic circuits can be mainly classified into two main categories: static logic circuits and dynamic logic circuits. Static logic circuits are circuits in which the output of the logic gate is always a logical function of the inputs and always available on the outputs of the gate regardless of time. A static logic circuit holds its output indefinitely. On the contrary, a dynamic logic circuit produces its output by storing charge in a capacitor. The output thus decays with time unless it is refreshed periodically. Dynamic or clocked logic gates are used to decrease complexity, increase speed, and lower power dissipation. The basic idea behind the dynamic logic is to use the capacitive input of the transistors to store a charge and thus remember a logic level for use later. Logic circuits may also be classified into combinational and sequential logic circuits. Combinational circuits produce outputs which are dependent on inputs only. There is no memory or feedback in the circuit. Circuits with feedback whose outputs depend on the inputs as well as the state of the circuit are called sequential circuits.
Web-Crawling Architecture in Accounting and Finance Research
Published in Journal of Computer Information Systems, 2022
Junru Zhang, Yuan George Shan, Fei Peng
A growing body of research in accounting and finance is adopting an automated process in data collection to examine textual information in corporate annual reports,1–4 earnings restatements,2 social media platforms5 and news releases.6 Wang and Yu and Zhang4 describe their automation processes with the use of Perl’s ‘HTML: Treebuilder’ module. However, the underlying architecture for web-crawling design is absent in the extant literature. While the mainstream accounting and finance research is undertaken in empirical settings, data collection is critical before any study can reach a conclusion. Much literature does not publish the logic of coding when collecting data, which may lower the replicability of studies using web-crawled data. As such, a discussion on crawling design remains imperative because the coding structure and logic may cause inconsistency in data collection, which affects the comparability, reliability and validity of the data across research.7 To respond to this concern in the extant literature, we raise the following research question: does web-crawling architecture logic influence data automation in accounting and finance research? In this study, we introduce web-crawling architecture through two logics: combinational logic (CL) and sequential logic (SL).
Implementation guidelines for mass customization: current characteristics and suggestions for improvement
Published in Production Planning & Control, 2018
Nikola Suzić, Cipriano Forza, Alessio Trentin, Zoran Anišić
Related to the issue above is the issue of the universal perspective that informs the sequential model we derived from the available MC-IGs (Figure 2)9. The literature seems to assume implicitly that the implementation of GT should always precede that of PP and the latter should always precede the implementation of PC. However, we argue that this sequential logic is not always appropriate. For example, consider a company that is at the beginning of MC implementation, but needs to quickly introduce a product configurator to react to the move of a competitor that has just introduced a product configurator in a market where tendering speed and pre-sale support to the customer are very important to win orders. By using this configurator, the competitor both sped the tendering process and improved its support to customers choosing among product alternatives. In this case, the company risks loss of customers in favour of the competitor and does not have time to follow a prescribed sequence of MC enabler implementation, which would delay its response to the competitor, but will instead implement the needed product configurator immediately. Most likely, this company will not introduce all functionalities of a product configurator because its limited, if any, adoption of S, M and PP would make the full implementation of a product configurator too demanding and time consuming. This example shows that the sequential logic of MC-IGs should be challenged, at least in certain contexts, and future MC-IGs should offer more flexible MC-IGs regarding a sequence of MC enabler implementation.
A rhodamine hydrazide–4-nitroindole-3-carboxaldehyde based turn on Hg2+ chemosensor: cytoplasmic live cell imaging, logic gate and memory device applications and computational studies
Published in Journal of Coordination Chemistry, 2018
Rahul Bhowmick, Abu Saleh Musha Islam, Mihir Sasmal, Atul Katarkar, Mahammad Ali
By sequential logic circuits a memory device can be constructed to store information. These circuits perform as a “Memory element” which is memorized due to one of the output signals acting as the input. We have delineated a sequential logic circuit exhibiting “Write − Read − Erase − Read” property with the help of binary logic function. In the present work, high emission output at 562 nm represent ON state (1) whereas weak emission output represents OFF state (0) at the same wavelength. Now two inputs Hg2+ and I− for the SET and RESET processes, respectively selected to construct the said memory device. This device memorizes binary number 1 for high emission value, that is, input A (Hg2+). But the reset input B (I−) memorizes the binary number 0 which erases the data (Figure 8). Thus, this molecular sequential logic function based circuit shows similar type of behavior like the traditional semiconductor based logic devices and it can be an essential tool for the development of a molecular microprocessor of integrated circuits in the near future. These write-erase-write cycles repeated many times with the same concentration of the system without any significant change in emission intensity is important.