To make the Octobot move autonomously, the developers used a microfluidic logic circuit, which directs the flow of its chemical reaction of hydrogen peroxide that's converted into gas when it comes in contact with its platinum components.
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According to Nikkei Technology, Sony was able to create such high frame-rate capture by sandwiching a DRAM layer between "the image sensing part and the logic circuit part" to create a system that can temporarily store more images at once before compiling them into a slow motion video.
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Norimitsu Sako. "Patent US7171636: Pass-transistor logic circuit and a method of designing thereof". 'It is known in the art to employ a "pass- transistor logic circuit" to reduce a number of elements and power consumption, and to improve operating speed.' XOR has the worst-case Karnaugh map—if implemented from simple gates, it requires more transistors than any other function.
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Gray codes are also used in labelling the axes of Karnaugh maps as well as in Händler circle graphs, both graphical methods for logic circuit minimization.
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This is because the complexity of the input circuitry increases the input capacitance of the device. Using logic gates with higher fan-in will help reducing the depth of a logic circuit.
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Byte, pp. 145–150, March 1992. was first commercially available in July 1971. The 4004 was the first random logic circuit integrated in one chip using the MOS (metal–oxide–semiconductor) silicon gate technology (SGT).
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In digital electronics, synchronous circuit is a digital circuit in which the changes in the state of memory elements are synchronized by a clock signal. In a sequential digital logic circuit, data is stored in memory devices called flip-flops or latches. The output of a flip-flop is constant until a pulse is applied to its "clock" input, upon which the input of the flip-flop is latched into its output. In a synchronous logic circuit, an electronic oscillator called the clock generates a string of pulses, the "clock signal".
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Transient load decoupling as described above is needed when there is a large load that gets switched quickly. The parasitic inductance in every (decoupling) capacitor may limit the suitable capacity and influence appropriate type if switching occurs very fast. Logic circuits tend to do sudden switching (an ideal logic circuit would switch from low voltage to high voltage instantaneously, with no middle voltage ever observable). So logic circuit boards often have a decoupling capacitor close to each logic IC connected from each power supply connection to a nearby ground.
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These problems are typically too difficult to model in simulation, or too time-consuming to simulate and often cross multiple clock domains. Field-programmable gate arrays have become a common measurement point for logic analyzers and are also used to debug the logic circuit.
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Ronja Twister is an electronic interface for free space optical datalink based on counter and shift register chips. It is a part of the Ronja design. It is effectively an optical Ethernet transceiver without the optical drive part. The original design has been superseded with Twister2 but the logic circuit remained the same.
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BAE Systems has tested two fluidically controlled unmanned aircraft, one starting in 2010 named Demon, and another starting in 2017 named MAGMA, with the University of Manchester. Octobot, a proof of concept soft-bodied autonomous robot containing a microfluidic logic circuit, has been developed by researchers at Harvard University's Wyss Institute for Biologically Inspired Engineering.
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The second approach is to attempt to provide charge to the capacitive loads through paths that are not primarily resistive. This is the principle behind adiabatic circuits. The charge is supplied either from a variable-voltage inductive power supply, or by other elements in a reversible-logic circuit. In both cases, the charge transfer must be primarily regulated by the non-resistive load.
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VHDL is generally used to write text models that describe a logic circuit. Such a model is processed by a synthesis program, only if it is part of the logic design. A simulation program is used to test the logic design using simulation models to represent the logic circuits that interface to the design. This collection of simulation models is commonly called a testbench.
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The fast operation of CML circuits is mainly due to their lower output voltage swing compared to the static CMOS circuits as well as the very fast current switching taking place at the input differential pair transistors. One of the primary requirements of a current- mode logic circuit is that the current bias transistor must remain in the saturation region in order to maintain a constant current.
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The output ("out") is connected together in metal (illustrated in cyan coloring). Connections between metal and polysilicon or diffusion are made through contacts (illustrated as black squares). The physical layout example matches the NAND logic circuit given in the previous example. The N device is manufactured on a P-type substrate while the P device is manufactured in an N-type well (n-well).
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There are several reasons for testing a logic circuit. When the circuit is first developed, it is necessary to verify that the design circuit meets the required functional and timing specifications. When multiple copies of a correctly designed circuit are being manufactured, it is essential to test each copy to ensure that the manufacturing process has not introduced any flaws.Brown S & Vranesic Z. (2009).
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OFET-based flexible display Organic CMOS logic circuit. Total thickness is less than 3 μm. Scale bar: 25 mm An organic field-effect transistor (OFET) is a field-effect transistor using an organic semiconductor in its channel. OFETs can be prepared either by vacuum evaporation of small molecules, by solution- casting of polymers or small molecules, or by mechanical transfer of a peeled single-crystalline organic layer onto a substrate.
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On the middle left are two phase detectors: adding feedback and removing one NAND gate produces a time frequency detector. The delay line avoids a dead band. On the right is a charge pump with a filter at its output. A phase detector or phase comparator is a frequency mixer, analog multiplier or logic circuit that generates a voltage signal which represents the difference in phase between two signal inputs.
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A direct-conversion or flash ADC has a bank of comparators sampling the input signal in parallel, each firing for a specific voltage range. The comparator bank feeds a logic circuit that generates a code for each voltage range. ADCs of this type have a large die size and high power dissipation. They are often used for video, wideband communications, or other fast signals in optical and magnetic storage.
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In principle any method that leads to a gate that is functionally complete (for example, either a NOR or a NAND gate) can be used to make any kind of digital logic circuit. Note that the use of 3-state logic for bus systems is not needed, and can be replaced by digital multiplexers, which can be built using only simple logic gates (such as NAND gates, NOR gates, or AND and OR gates).
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A typical controller contains three bidirectional outputs (i.e., frequency-controlled three-phase output), which are controlled by a logic circuit. Simple controllers employ comparators to determine when the output phase should be advanced, while more advanced controllers employ a microcontroller to manage acceleration, control speed and fine-tune efficiency. Controllers that sense rotor position based on back-EMF have extra challenges in initiating motion because no back-EMF is produced when the rotor is stationary.
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Race condition in a logic circuit. Here, ∆t1 and ∆t2 represent the propagation delays of the logic elements. When the input value A changes from low to high, the circuit outputs a short spike of duration (∆t1 \+ ∆t2) − ∆t2 = ∆t1. A race condition or race hazard is the condition of an electronics, software, or other system where the system's substantive behavior is dependent on the sequence or timing of other uncontrollable events.
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Organic CMOS logic circuit. Total thickness is less than 3 μm. Scale bar: 25 mm Organic electronics is a field of materials science concerning the design, synthesis, characterization, and application of organic molecules or polymers that show desirable electronic properties such as conductivity. Unlike conventional inorganic conductors and semiconductors, organic electronic materials are constructed from organic (carbon-based) molecules or polymers using synthetic strategies developed in the context of organic chemistry and polymer chemistry.
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Until the 1980s, there were not many innovations. In 1985, Edward Sammsel proposed a machine that extracted the cards from the bottom of two deck holders and put them in a second compartment. Another extractor would eject the card that was taken by the dealer. The order in which the two cards were taken from the holders was driven by a logic circuit whose main parts were a counter and a decoder.
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Researchers have also constructed the CMOS inverter (logic circuit) by combining a phosphorene PMOS transistor with a MoS2 NMOS transistor, achieving high heterogeneous integration of semiconducting phosphorene crystals as a new channel material for potential electronic applications. In the inverter, the power supply voltage is set to be 1 V. The output voltage shows a clear transition from VDD to 0 within the input voltage range from −10 to −2 V. A maximum gain of ~1.4 is attained.
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Octobot is a 3D printed soft-bodied autonomous robot that shaped like a small octopus, and its soft body is made of 3D printed silicone gel. It uses hydrogen peroxide as its main power source and also contains a microfluidic logic circuit. Octobot is said to be able to move on its own without any aid by a battery or an electrical power source. The hydrogen peroxide flows around a network of 3D printed hollows (or freckles) within the body of the robot.
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One difference between magnetic logic and conventional tube or transistor systems is that it is the current that defines the logic levels, not voltage.Scarrott Since the magnetic cores were open in the middle, any number of control lines could be threaded through them. This was particularly useful when implementing a best two-out-of-three, a common logic circuit used in binary adders. Another possibility is to use the same core as the switching element in several different portions of the machines logic.
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In automata theory, sequential logic is a type of logic circuit whose output depends not only on the present value of its input signals but on the sequence of past inputs, the input history as well. This is in contrast to combinational logic, whose output is a function of only the present input. That is, sequential logic has state (memory) while combinational logic does not. Sequential logic is used to construct finite state machines, a basic building block in all digital circuitry.
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The combinational ATPG method allows testing the individual nodes (or flip-flops) of the logic circuit without being concerned with the operation of the overall circuit. During test, a so-called scan-mode is enabled forcing all flip-flops (FFs) to be connected in a simplified fashion, effectively bypassing their interconnections as intended during normal operation. This allows using a relatively simple vector matrix to quickly test all the comprising FFs, as well as to trace failures to specific FFs.
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In digital electronics, an asynchronous circuit, or self-timed circuit, is a sequential digital logic circuit which is not governed by a clock circuit or global clock signal. Instead it often uses signals that indicate completion of instructions and operations, specified by simple data transfer protocols. This type of circuit is contrasted with synchronous circuits, in which changes to the signal values in the circuit are triggered by repetitive pulses called a clock signal. Most digital devices today use synchronous circuits.
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Applying the XOR gate's output to a low-pass filter results in an analog voltage that is proportional to the phase difference between the two signals. It requires inputs that are symmetrical square waves, or nearly so. The remainder of its characteristics are very similar to the analog mixer for capture range, lock time, reference spurious and low-pass filter requirements. Digital phase detectors can also be based on a sample and hold circuit, a charge pump, or a logic circuit consisting of flip-flops.
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Even a simple stuck-at fault requires a sequence of vectors for detection in a sequential circuit. Also, due to the presence of memory elements, the controllability and observability of the internal signals in a sequential circuit are in general much more difficult than those in a combinational logic circuit. These factors make the complexity of sequential ATPG much higher than that of combinational ATPG, where a scan-chain (i.e. switchable, for-test-only signal chain) is added to allow simple access to the individual nodes.
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When large currents are switched at high frequencies, e.g. in DC-to-DC converters or large electric motors, multiple transistors are sometimes provided in parallel, so as to provide sufficiently high switching currents and switching power. The switching signal for a transistor is usually generated by a logic circuit or a microcontroller, which provides an output signal that typically is limited to a few milliamperes of current. Consequently, a transistor which is directly driven by such a signal would switch very slowly, with correspondingly high power loss.
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The Tseytin transformation, alternatively written Tseitin transformation, takes as input an arbitrary combinatorial logic circuit and produces a boolean formula in conjunctive normal form (CNF), which can be solved by a CNF-SAT solver. The length of the formula is linear in the size of the circuit. Input vectors that make the circuit output "true" are in 1-to-1 correspondence with assignments that satisfy the formula. This reduces the problem of circuit satisfiability on any circuit (including any formula) to the satisfiability problem on 3-CNF formulas.
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Processes related to functional decomposition are prevalent throughout the fields of knowledge representation and machine learning. Hierarchical model induction techniques such as Logic circuit minimization, decision trees, grammatical inference, hierarchical clustering, and quadtree decomposition are all examples of function decomposition. A review of other applications and function decomposition can be found in , which also presents methods based on information theory and graph theory. Many statistical inference methods can be thought of as implementing a function decomposition process in the presence of noise; that is, where functional dependencies are only expected to hold approximately.
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Tokyo University of Science Parametron is a logic circuit element invented by Eiichi Goto in 1954.Information Processing Society of Japan - Parametron The parametron is essentially a resonant circuit with a nonlinear reactive element which oscillates at half the driving frequency. The oscillation can be made to represent a binary digit by the choice between two stationary phases π radians (180 degrees) apart.U.S. Patent and Trademark Office - Class 307, Electrical Transmission or Interconnection Systems - Subclass 402, Parametrons Parametrons were used in early Japanese computers from 1954 through the early 1960s.
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A typical Manhattan wiring scheme (logic circuit is omitted) Manhattan wiring (also known as right-angle wiring) is a technique for laying out circuits in computer engineering. Inputs to a circuit (specifically, the interconnects from the inputs) are aligned into a grid, and the circuit "taps" (connects to) them perpendicularly. This may be done either virtually or physically. That is, it may be shown this way only in the documentation and the actual circuit may look nothing like that; or it may be laid out that way on the physical chip.
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Voltage changes on the 5 outputs of the binary counter counting from 00000, left to 11111 (or 31), right (vertically). In digital logic and computing, a counter is a device which stores (and sometimes displays) the number of times a particular event or process has occurred, often in relationship to a clock. The most common type is a sequential digital logic circuit with an input line called the clock and multiple output lines. The values on the output lines represent a number in the binary or BCD number system.
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In 1974, David Erickson and Richard Kronmal proposed a shuffler based upon a logic circuit with binary gates. The deck was placed in a holder and cards were extracted one by one, sent into a downward slope channel containing some flaps that would be activated or deactivated, depending upon which stack should be fed. The flap forwarded the card into the proper container and was moved by a coil controlled by the pseudo-random generator. Synchronization was important and several methods were used to ensure that the card would follow the correct path.
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The Capricorn CPU was implemented as a silicon- gate NMOS logic circuit (4.93×4.01 mm) in a 28-pin dual in-line package, with an 8-bit, multiplexed external bus. The CPU chip consumed 330 mW at 625 kHz. CPU timing is controlled by four non-overlapping clock phases with 200 nanosecond width and 200 nanosecond spacing, for an overall clock cycle of 1.6 microseconds, equivalent to 625 kHz clock frequency. The complete system included support chips co-designed with the CPU, such as a dynamic memory controller, keyboard controller with timers, printer controller and CRT controller.
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The ACR-1000 design currently calls for a variety of safety systems, most of which are evolutionary derivatives of the systems utilized on the CANDU 6 reactor design. Each ACR requires both SDS1 & SDS2 to be online and fully operational before they will operate at any power level.CANDU 6 – Safety Systems – Special Safety Systems Safety Shutdown System 1 (SDS1): SDS1 is designed to rapidly and automatically terminate reactor operation. Neutron-absorbing rods (control rods that shut down the nuclear chain reaction) are stored inside isolated channels located directly above the reactor vessel (calandria) and are controlled via a triple- channel logic circuit.
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Each nozzle has an electronically controlled valve, all of which are controlled via a triple-channel logic circuit. When any 2 of the 3 circuit paths are activated (due to sensing the need for emergency reactor trip), each of these valves are opened and Gd(NO3)3 solution is injected through the nozzles to mix with the heavy-water moderator liquid in the reactor vessel (calandria). The result is that the reactor heat output is reduced by 90% within 2 seconds. Reserve water system (RWS): The RWS consists of a water tank located at a high elevation within the reactor building.
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In digital logic, a hazard in a system is an undesirable effect caused by either a deficiency in the system or external influences. Logic hazards are manifestations of a problem in which changes in the input variables do not change the output correctly due to some form of delay caused by logic elements (NOT, AND, OR gates, etc.) This results in the logic not performing its function properly. The three different most common kinds of hazards are usually referred to as static, dynamic and function hazards. Hazards are a temporary problem, as the logic circuit will eventually settle to the desired function.
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A dynamic hazard is the possibility of an output changing more than once as a result of a single input change. Dynamic hazards often occur in larger logic circuits where there are different routes to the output (from the input). If each route has a different delay, then it quickly becomes clear that there is the potential for changing output values that differ from the required / expected output. E.g. A logic circuit is meant to change output state from 1 to 0, but instead changes from 1 to 0 then 1 and finally rests at the correct value 0.
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Consider now a dynamic logic implementation of the same logic function: 200px The dynamic logic circuit requires two phases. The first phase, when Clock is low, is called the setup phase or the precharge phase and the second phase, when Clock is high, is called the evaluation phase. In the setup phase, the output is driven high unconditionally (no matter the values of the inputs A and B). The capacitor, which represents the load capacitance of this gate, becomes charged. Because the transistor at the bottom is turned off, it is impossible for the output to be driven low during this phase.
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The Orion was a mid-range mainframe computer introduced by Ferranti in 1959 and installed for the first time in 1961. Ferranti positioned Orion to be their primary offering during the early 1960s, complementing their high-end Atlas and smaller systems like the Sirius and Argus. The Orion was based on a new type of logic circuit known as "Neuron" and included built-in multitasking support, one of the earliest commercial machines to do so (the KDF9 being a contemporary). Performance of the system was much less than expected and the Orion was a business disaster, selling only about eleven machines.
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Electronic calculator prototype, made by Thomas E. Osborne for Hewlett-Packard, 1964, in the National Museum of American History The unit was descended from a prototype produced by engineer Thomas "Tom" E. Osborne, who joined the company when HP decided to adopt the project."How the Model 9100A Was Developed", Bernard M. Oliver, September 1968, Hewlett-Packard Journal]1994 letter from Tom Osborne to Barney Oliver, hp9825.com An engineering triumph at the time, the logic circuit was produced without any integrated circuits, the assembly of the CPU having been entirely executed in discrete components. With CRT readout, magnetic card storage, and printer, the price was around $5,000 ($ today).
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BASIC programs and some machine-language software commonly did this for performance reasons. PETs with 12-inch displays (all 8000s and later 4000s) used a video controller based on the Motorola 6845 CRTC chip (unlike the TTL logic circuit in 2001/3000s/early 4000s) that eliminated the snow problem, but also placed a CRT control register in place of where the VBLANK flag had been on the 2001/3000. Hence software that tried to disable it would end up throwing the monitor out of sync and destroying the flyback transformer. BASIC programs intended for the 2001/3000 thus had to be modified in order to run safely on 12-inch PETs.
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During switching, the gate capacitor of the transistor may draw current so quickly that it causes a current overdraw in the logic circuit or microcontroller, causing overheating which leads to permanent damage or even complete destruction of the chip. To prevent this from happening, a gate driver is provided between the microcontroller output signal and the power transistor. Charge pumps are often used in H-Bridges in high side drivers for gate driving the high side n-channel power MOSFETs and IGBTs. These devices are used because of their good performance, but require a gate drive voltage a few volts above the power rail.
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Each basic operation is represented by a particular combination of bits, known as the machine language opcode; while executing instructions in a machine language program, the CPU decides which operation to perform by "decoding" the opcode. A complete machine language instruction consists of an opcode and, in many cases, additional bits that specify arguments for the operation (for example, the numbers to be summed in the case of an addition operation). Going up the complexity scale, a machine language program is a collection of machine language instructions that the CPU executes. The actual mathematical operation for each instruction is performed by a combinational logic circuit within the CPU's processor known as the arithmetic logic unit or ALU.
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Levy and Turnbull pressed for development of a production system, while Porter was suggested they move to a transistorized version of the computer. Porter had made the same proposal to the Navy in order to cure the size and reliability problems they were having the tube-based DATAR, and had signed a contract for a transistorized DATAR in early 1955. Since the Navy was paying for much of the development of the circuitry, the new machine would be inexpensive to develop. Porter offered a $65,000 contract for the new computer, known as the Route Reference Computer, which Turnbull signed in August 1955. Ferranti had based both proposals on Philco's SB-100 transistor and their Transac logic circuit design.
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Use of these alternative symbols can make logic circuit diagrams much clearer and help to show accidental connection of an active high output to an active low input or vice versa. Any connection that has logic negations at both ends can be replaced by a negationless connection and a suitable change of gate or vice versa. Any connection that has a negation at one end and no negation at the other can be made easier to interpret by instead using the De Morgan equivalent symbol at either of the two ends. When negation or polarity indicators on both ends of a connection match, there is no logic negation in that path (effectively, bubbles "cancel"), making it easier to follow logic states from one symbol to the next.
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The simple and manageable architecture of the system, extensive documentation of the manufacturer and not least the free usage of the system software enable miniaturized replica of the Z 1013 with today's technical means, with a manageable effort. Such modern realization was the first time in 2013 - as well as other home computer systems - as an implementation of a programmable logic circuit (FPGA) in addition to embedded systems. The simulation using FPGA technology was initially intended only as a technical feasibility study, but in retrospect also their practical utility to the test. Due to the miniaturization and the possibility of battery operation, it is an easily stowable, reliably operating and portable alternative to the original schonenswerten technique Volker Urban: Retrocomputing auf FPGA.
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For example, the time delay along a path from the output of a D-Flip Flop, through combinatorial logic gates, then into the next D-Flip Flop input must satisfy (be less than) the time period between synchronizing clock pulses to the two flip flops. When the delay through the elements is greater than the clock cycle time, the elements are said to be on the critical path. The circuit will not function when the path delay exceeds the clock cycle delay so modifying the circuit to remove the timing failure (and eliminate the critical path) is an important part of the logic design engineer's task. Many times logic circuit changes are handled by user's EDA tools based on timing constraint directives prepared by a designer.
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The combinational logic circuitry of the 74181 integrated circuit, which is a simple four-bit ALU An ALU is a combinational logic circuit, meaning that its outputs will change asynchronously in response to input changes. In normal operation, stable signals are applied to all of the ALU inputs and, when enough time (known as the "propagation delay") has passed for the signals to propagate through the ALU circuitry, the result of the ALU operation appears at the ALU outputs. The external circuitry connected to the ALU is responsible for ensuring the stability of ALU input signals throughout the operation, and for allowing sufficient time for the signals to propagate through the ALU before sampling the ALU result. In general, external circuitry controls an ALU by applying signals to its inputs.
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The designer of a reliable diode logic circuit is usually limited to what the diode specification provides which is often less than the equation suggests. Typically the specification will primarily provide a maximum forward voltage drop at one or more forward currents and a reverse leakage current. It will also provide a maximum reverse voltage limited by zener or avalanche breakdown. Typical worst case specifications are shown below for both germanium and silicon PN diodes. Germanium diode: :Max forward voltage at 10 mA = 1 volt @ 0 to 85 °C :Max reverse leakage current at 15 volts = 100 microamps @ 85 °C Silicon diode: :Max forward voltage at 10 mA = 1 volt @ 0 to 125 °C :Max reverse leakage current at 15 volts = 1 microamps @ 85 °C Effects of component manufacturing variations and temperature are usually included in these specifications.
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Notable innovations of computer science faculty and alumni include the first method for representing surface textures in graphical images, the Gouraud shading model, magnetic ink printing technology, the Johnson counter logic circuit, the oldest algebraic mathematics package still in use (REDUCE), the Phong reflection model, the Phong shading method, and the rendering equation. Through the movement of Utah graduates and faculty, research at the University spread outward to laboratories like Xerox Parc, JPL, and the New York Institute of Technology. Present graphics research is focused on biomedical applications for visualization, scientific computing, and image analysis at the Scientific Computing and Imaging Institute. ; Dentistry In March 2012, the university received unanimous approval from the board of trustees to create a new academic college, the School of Dentistry, which is the university's first new college in sixty years.
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