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74-441: Unlike board-level designs composed of discrete parts, it is not practical to breadboard integrated circuits before manufacture. Further, the high costs of photolithographic masks and other manufacturing prerequisites make it essential to design the circuit to be as close to perfect as possible before the integrated circuit is first built. Simulating the circuit with SPICE is the industry-standard way to verify circuit operation at

148-428: A Printed Circuit Breadboard . Both examples refer to and describe other types of breadboards as prior art . In 1960, Orville Thompson of DeVry Technical Institute patented a solderless breadboard connecting rows of holes together with spring metal. In 1971, Ronald Portugal of E&L Instruments patented a similar concept with holes in 0.1 inches (2.54 mm) spacings, the same as DIP IC packages, which became

222-441: A compiler or an assembler . The resulting executable is machine code ready for the computer. Alternatively, source code can be executed without conversion via an interpreter . An interpreter loads the source code into memory. It simultaneously translates and executes each statement . A method that combines compilation and interpretation is to first produce bytecode . Bytecode is an intermediate representation of source code that

296-604: A perfboard or stripboard , breadboards do not require soldering or destruction of tracks and are hence reusable. For this reason, breadboards are also popular with students and in technological education. A variety of electronic systems may be prototyped by using breadboards, from small analog and digital circuits to complete central processing units (CPUs). Compared to more permanent circuit connection methods, modern breadboards have high parasitic capacitance , relatively high resistance, and less reliable connections, which are subject to jostle and physical degradation. Signaling

370-462: A source-code editor that can alert the programmer to common errors. Modification often includes code refactoring (improving the structure without changing functionality) and restructuring (improving structure and functionality at the same time). Nearly every change to code will introduce new bugs or unexpected ripple effects , which require another round of fixes. Code reviews by other developers are often used to scrutinize new code added to

444-430: A trade secret . Proprietary, secret source code and algorithms are widely used for sensitive government applications such as criminal justice , which results in black box behavior with a lack of transparency into the algorithm's methodology. The result is avoidance of public scrutiny of issues such as bias. Access to the source code (not just the object code) is essential to modifying it. Understanding existing code

518-790: A C++ re-write of the original spice3f5 code. Other open-source simulators not developed by academics are QUCS , QUCS-S, Xyce, and Qucsator. Berkeley SPICE inspired and served as a basis for many other circuit simulation programs, in academia, in industry, and in commercial products. The first commercial version of SPICE is ISPICE, an interactive version on a timeshare service, National CSS . The most prominent commercial versions of SPICE include HSPICE (originally commercialized by Ashawna and Kim Hailey of Meta Software, but now owned by Synopsys ) and PSPICE (now owned by Cadence Design Systems ). The integrated circuit industry adopted SPICE quickly, and until commercial versions became well developed many IC design houses had proprietary versions of SPICE. Today

592-529: A bottleneck. This led to the introduction of high-level programming languages such as Fortran in the mid-1950s. These languages abstracted away the details of the hardware, instead being designed to express algorithms that could be understood more easily by humans. As instructions distinct from the underlying computer hardware , software is therefore relatively recent, dating to these early high-level programming languages such as Fortran , Lisp , and Cobol . The invention of high-level programming languages

666-411: A breadboard. Modern circuit designs are generally developed using a schematic capture and simulation system, and tested in software simulation before the first prototype circuits are built on a printed circuit board . Integrated circuit designs are a more extreme version of the same process: since producing prototype silicon is costly, extensive software simulations are performed before fabricating

740-687: A bus strip are indicated by gaps in the color marking. Bus strips typically run down one or both sides of a terminal strip or between terminal strips. On large breadboards additional bus strips can often be found on the top and bottom of terminal strips. Some manufacturers provide separate bus and terminal strips. Others just provide breadboard blocks which contain both in one block. Jump wires (also called jumper wires) for solderless breadboarding can be obtained in ready-to-use jump wire sets or can be manually manufactured. The latter can become tedious work for larger circuits. Ready-to-use jump wires come in different qualities, some even with tiny plugs attached to

814-507: A circuit" remains synonymous with circuit simulation. SPICE source code was from the beginning distributed by UC Berkeley for a nominal charge (to cover the cost of magnetic tape). The license originally included distribution restrictions for countries not considered friendly to the US, but the source code is currently covered by the BSD license . The birth of SPICE was named an IEEE Milestone in 2011;

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888-470: A combined Ebers–Moll and Gummel–Poon bipolar model , a JFET model, and a model for a junction diode . In addition, it had many other elements: resistors, capacitors, inductors (including coupling ), independent voltage and current sources , ideal transmission lines , active components and voltage and current controlled sources. SPICE3 added more sophisticated MOSFET models, which were required due to advances in semiconductor technology. In particular,

962-530: A conference in 1973. SPICE1 is coded in FORTRAN and to construct the circuit equations uses nodal analysis , which has limitations in representing inductors, floating voltage sources and the various forms of controlled sources. SPICE1 has relatively few circuit elements available and uses a fixed-timestep transient analysis . The real popularity of SPICE started with SPICE2 in 1975. SPICE2, also coded in FORTRAN,

1036-684: A few IC manufacturers, typically the larger companies, have groups continuing to develop SPICE-based circuit simulation programs. Among these are ADICE and LTspice at Analog Devices , QSPICE at Qorvo , MCSPICE, followed by Mica at Freescale Semiconductor , now NXP Semiconductors , and TINA-TI at Texas Instruments . Both LTspice and TINA-TI come bundled with models from their respective company. Other companies maintain internal circuit simulators which are not directly based upon SPICE, among them PowerSpice at IBM , TITAN at Infineon Technologies , Lynx at Intel Corporation , and Pstar at NXP Semiconductors also. SPICE became popular because it contained

1110-452: A few wire colors are reserved for the supply voltages and ground (e.g., red, blue, black), some are reserved for main signals, and the rest are simply used where convenient. Some ready-to-use jump wire sets use the color to indicate the length of the wires, but these sets do not allow a meaningful color-coding schema. In a more robust variant, one or more breadboard strips are mounted on a sheet of metal. Typically, that backing sheet also holds

1184-641: A form factor barely larger than a large postage stamp, available in the American hobby market (and elsewhere) for a few dollars, allowing fairly sophisticated breadboard projects to be created at modest expense. Due to relatively large parasitic capacitance compared to a properly laid out PCB (approx 2 pF between adjacent contact columns ), high inductance of some connections and a relatively high and not very reproducible contact resistance , solderless breadboards are limited to operation at relatively low frequencies, usually less than 10  MHz , depending on

1258-430: A large breadboard. The main areas, to hold most of the electronic components, are called terminal strips . In the middle of a terminal strip of a breadboard, one typically finds a notch running in parallel to the long side. The notch is to mark the centerline of the terminal strip and provides limited airflow (cooling) to DIP ICs straddling the centerline . The clips on the right and left of the notch are each connected in

1332-421: A metal breadboard affords a desirable solderable ground plane, often an unetched piece of printed circuit board; integrated circuits are sometimes stuck upside down to the breadboard and soldered to directly, a technique sometimes called " dead bug " construction because of its appearance. Examples of dead bug with ground plane construction are illustrated in a Linear Technologies application note. A common use in

1406-527: A more reliable interconnection technology, to have a likelihood of working over a usable time period. Alternative methods to create prototypes are point-to-point construction (reminiscent of the original wooden breadboards), wire wrap , wiring pencil , and boards like the stripboard. Complicated systems, such as modern computers comprising millions of transistors , diodes , and resistors , do not lend themselves to prototyping using breadboards, as their complex designs can be difficult to lay out and debug on

1480-530: A number of binding posts . These posts provide a clean way to connect an external power supply. This type of breadboard may be slightly easier to handle. Some manufacturers provide high-end versions of solderless breadboards. These are typically high-quality breadboard modules mounted on a flat casing. The casing contains additional equipment for breadboarding, such as a power supply , one or more signal generators , serial interfaces , LED display or LCD modules, and logic probes . For high-frequency development,

1554-486: A pneumatic FET. SPICE has been applied to model the interface between biological and electronic systems , e.g. as a design tools for synthetic biology and for the virtual prototyping of biosensors and lab-on-chip. SPICE has been applied in operations research to evaluate perturbed supply chains . Breadboard A breadboard , solderless breadboard , or protoboard is a construction base used to build semi-permanent prototypes of electronic circuits . Unlike

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1628-444: A project. The purpose of this phase is often to verify that the code meets style and maintainability standards and that it is a correct implementation of the software design . According to some estimates, code review dramatically reduce the number of bugs persisting after software testing is complete. Along with software testing that works by executing the code, static program analysis uses automated tools to detect problems with

1702-567: A public-domain circuit simulator containing the modern analyses and features needed to become a successor in popularity to SPICE has not yet emerged. It is very important to use appropriate analyses with carefully chosen parameters. For example, application of linear analysis to nonlinear circuits should be justified separately. Also, application of transient analysis with default simulation parameters can lead to qualitatively wrong conclusions on circuit dynamics. SPICE2 includes many semiconductor device compact models : three levels of MOSFET model,

1776-420: A radial way; typically five clips (i.e., beneath five holes) in a row on each side of the notch are electrically connected. The five columns on the left of the notch are often marked as A, B, C, D, and E, while the ones on the right are marked F, G, H, I and J. When a "skinny" dual in-line pin package (DIP) integrated circuit (such as a typical DIP-14 or DIP-16, which have a 0.3-inch (7.6 mm) separation between

1850-563: A single simulation run. SPICE may very well simulate the electronics part of a motor drive. However it will equally well describe the electro-mechanical model of the motor. Again this is achieved by mapping mechanical onto the electrical elements (torque → voltage, angular velocity → current, coefficient of viscous friction → resistance, moment of inertia → inductance). So again the final model consists of only SPICE compatible lumped circuit elements, but one gains mechanical together with electrical data during simulation. Electromagnetic modeling

1924-420: A socket on the adapter, while smaller components (e.g., SMD resistors) are usually soldered directly onto the adapter. The adapter is then plugged into the breadboard via the 0.1 in (2.54 mm) connectors. However, the need to solder the components onto the adapter negates some of the advantage of using a solderless breadboard. Very complex circuits can become unmanageable on a solderless breadboard due to

1998-406: A specific platform, source code can be ported to a different machine and recompiled there. For the same source code, object code can vary significantly—not only based on the machine for which it is compiled, but also based on performance optimization from the compiler. Most programs do not contain all the resources needed to run them and rely on external libraries . Part of the compiler's function

2072-445: A typical 784 to 910 tie point solderless breadboard. Most breadboards are designed to accommodate 17, 30 or 64 rows in the mini, half, and full configurations respectively. To provide power to the electronic components, bus strips are used. A bus strip usually contains two columns: one for ground and one for a supply voltage. However, some breadboards only provide a single-column power distribution bus strip on each long side. Typically

2146-405: Is a plain text computer program written in a programming language . A programmer writes the human readable source code to control the behavior of a computer . Since a computer, at base, only understands machine code , source code must be translated before a computer can execute it. The translation process can be implemented three ways. Source code can be converted into machine code by

2220-466: Is a much-improved program with more circuit elements, variable timestep transient analysis using either the trapezoidal (second order Adams-Moulton method ) or the Gear integration method (also known as BDF ), equation formulation via modified nodal analysis (avoiding the limitations of nodal analysis), and an innovative FORTRAN-based memory allocation system. Ellis Cohen led development from version 2B to

2294-569: Is accessible to a SPICE simulator via the PEEC (partial element equivalent circuit) method. Maxwell's equations have been mapped, RLC, Skin effect, dielectric or magnetic materials and incident or radiated fields have been modelled. However, as of 2019, SPICE cannot be used to "simulate photonics and electronics together in a photonic circuit simulator ", and thus it is not yet considered as a test simulator for photonic integrated circuits. Micro-fluidic circuits have been modelled with SPICE by creating

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2368-442: Is an overarching term that can refer to a code's correct and efficient behavior, its reusability and portability , or the ease of modification. It is usually more cost-effective to build quality into the product from the beginning rather than try to add it later in the development process. Higher quality code will reduce lifetime cost to both suppliers and customers as it is more reliable and easier to maintain . Maintainability

2442-635: Is done by automatically updating semiconductor model parameters for temperature, allowing the circuit to be simulated at temperature extremes. Other circuit simulators have since added many analyses beyond those in SPICE2 to address changing industry requirements. Parametric sweeps were added to analyze circuit performance with changing manufacturing tolerances or operating conditions. Loop gain and stability calculations were added for analog circuits. Harmonic balance or time-domain steady state analyses were added for RF and switched-capacitor circuit design. However,

2516-452: Is frequently cited as a contributing factor to the maturation of their programming skills. Some people consider source code an expressive artistic medium . Source code often contains comments —blocks of text marked for the compiler to ignore. This content is not part of the program logic, but is instead intended to help readers understand the program. Companies often keep the source code confidential in order to hide algorithms considered

2590-444: Is limited to about 10 MHz, and not everything works properly even well below that frequency. In the early days of radio, amateurs nailed bare copper wires or terminal strips to a wooden board (often literally a bread cutting board ) and soldered electronic components to them. Sometimes a paper schematic diagram was first glued to the board as a guide to placing terminals, then components and wires were installed over their symbols on

2664-496: Is necessary to understand how it works and before modifying it. The rate of understanding depends both on the code base as well as the skill of the programmer. Experienced programmers have an easier time understanding what the code does at a high level. Software visualization is sometimes used to speed up this process. Many software programmers use an integrated development environment (IDE) to improve their productivity. IDEs typically have several features built in, including

2738-470: Is quickly interpreted. The first programmable computers, which appeared at the end of the 1940s, were programmed in machine language (simple instructions that could be directly executed by the processor). Machine language was difficult to debug and was not portable between different computer systems. Initially, hardware resources were scarce and expensive, while human resources were cheaper. As programs grew more complex, programmer productivity became

2812-631: Is that many software engineering courses do not emphasize it. Development engineers who know that they will not be responsible for maintaining the software do not have an incentive to build in maintainability. The situation varies worldwide, but in the United States before 1974, software and its source code was not copyrightable and therefore always public domain software . In 1974, the US Commission on New Technological Uses of Copyrighted Works (CONTU) decided that "computer programs, to

2886-477: Is the quality of software enabling it to be easily modified without breaking existing functionality. Following coding conventions such as using clear function and variable names that correspond to their purpose makes maintenance easier. Use of conditional loop statements only if the code could execute more than once, and eliminating code that will never execute can also increase understandability. Many software development organizations neglect maintainability during

2960-530: Is then developed for the MCU to test, debug, and interact with the circuit prototype. High frequency operation is then largely confined to the SoC's PCB. In the case of high speed interconnects such as SPI and I²C, these can be debugged at a lower speed and later rewired using a different circuit assembly methodology to exploit full-speed operation. A single small SoC often provides most of these electrical interface options in

3034-418: Is to link these files in such a way that the program can be executed by the hardware. Software developers often use configuration management to track changes to source code files ( version control ). The configuration management system also keeps track of which object code file corresponds to which version of the source code file. The number of lines of source code is often used as a metric when evaluating

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3108-558: The BSIM family of models were added, which were also developed at UC Berkeley. Commercial and industrial SPICE simulators have added many other device models as technology advanced and earlier models became inadequate. To attempt standardization of these models so that a set of model parameters may be used in different simulators, an industry working group was formed, the Compact Model Council , to choose, maintain and promote

3182-486: The United States Department of Defense that required the capability to evaluate the radiation hardness of a circuit. When Nagel's original advisor, Prof. Rohrer, left Berkeley, Prof. Pederson became his advisor. Pederson insisted that CANCER, a proprietary program, be rewritten enough that restrictions could be removed and the program could be put in the public domain . SPICE1 was first presented at

3256-439: The dual in-line layout—it is impossible to provide the correct electrical connectivity. Sometimes small PCB adapters called "breakout adapters" can be used to fit the component to the board. Such adapters carry one or more components and have 0.1 inches (2.54 mm) spaced male connector pins in a single in-line or dual in-line layout, for insertion into a solderless breadboard. Larger components are usually plugged into

3330-579: The system on a chip (SoC) era is to obtain an microcontroller (MCU) on a pre-assembled printed circuit board (PCB) which exposes an array of input/output (IO) pins in a header suitable to plug into a breadboard, and then to prototype a circuit which exploits one or more of the MCU's peripherals, such as general-purpose input/output (GPIO), UART / USART serial transceivers, analog-to-digital converter (ADC), digital-to-analog converter (DAC), pulse-width modulation (PWM; used in motor control ), Serial Peripheral Interface (SPI), or I²C . Firmware

3404-479: The analyses and models needed to design integrated circuits of the time, and was robust enough and fast enough to be practical to use. Precursors to SPICE often had a single purpose: The BIAS program, for example, did simulation of bipolar transistor circuit operating points; the SLIC program did only small-signal analyses. SPICE combined operating point solutions, transient analysis, and various small-signal analyses with

3478-429: The basis of the modern solderless breadboard that is commonly used today. A modern solderless breadboard socket consists of a perforated block of plastic with numerous tin plated phosphor bronze or nickel silver alloy spring clips under the perforations. The clips are often called tie points or contact points . The number of tie points is often given in the specification of the breadboard. The spacing between

3552-498: The circuit elements and device models needed to successfully simulate many circuits. SPICE2 includes these analyses: Since SPICE is generally used to model circuits with nonlinear elements , the small signal analyses are necessarily preceded by a quiescent point calculation at which the circuit is linearized. SPICE2 also contains code for other small-signal analyses: sensitivity analysis , pole-zero analysis , and small-signal distortion analysis. Analysis at various temperatures

3626-444: The clips (lead pitch) is typically 0.1 inches (2.54 mm). Integrated circuits (ICs) in dual in-line packages (DIPs) can be inserted to straddle the centerline of the block. Interconnecting wires and the leads of discrete components (such as capacitors , resistors , and inductors ) can be inserted into the remaining free holes to complete the circuit. Where ICs are not used, discrete components and connecting wires may use any of

3700-426: The development phase, even though it will increase long-term costs. Technical debt is incurred when programmers, often out of laziness or urgency to meet a deadline, choose quick and dirty solutions rather than build maintainability into their code. A common cause is underestimates in software development effort estimation , leading to insufficient resources allocated to development. A challenge with maintainability

3774-618: The effect of component variations on performance, a task which is impractical using calculations by hand for a circuit of any appreciable complexity. Circuit simulation programs, of which SPICE and derivatives are the most prominent, take a text netlist describing the circuit elements ( transistors , resistors , capacitors , etc.) and their connections, and translate this description into equations to be solved. The general equations produced are nonlinear differential algebraic equations which are solved using implicit integration methods , Newton's method and sparse matrix techniques. SPICE

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3848-565: The electronic SPICE elements (heat capacity → capacitance, thermal conductance/resistance → conductance/resistance, temperature → voltage, heat flow or heat generated → current ). As thermal and electronic systems are closely linked by power dissipation and cooling systems, electro-thermal simulation today is supported by semiconductor device manufacturers offering (transistor) models with both electrical and thermal nodes. So one may obtain electrical power dissipation, resulting in self-heating causing parameter variations, and cooling system efficiency in

3922-720: The entry mentions that SPICE "evolved to become the worldwide standard integrated circuit simulator". Nagel was awarded the 2019 IEEE Donald O. Pederson Award in Solid-State Circuits for the development of SPICE. No newer versions of Berkeley SPICE have been released after version 3f5 in 1993. Since then, the open-source or academic continuations of SPICE include: XSPICE, developed at Georgia Tech , which added mixed analog/digital "code models" for behavioral simulation; CIDER (previously CODECS), developed by UC Berkeley and Oregon State University, which added semiconductor device simulation ; Ngspice , based on SPICE 3f5; WRspice,

3996-406: The extent that they embody an author's original creation, are proper subject matter of copyright". Proprietary software is rarely distributed as source code. Although the term open-source software literally refers to public access to the source code , open-source software has additional requirements: free redistribution, permission to modify the source code and release derivative works under

4070-420: The final printed wiring board, such as parasitic resistances and capacitances , whose effects can often be estimated more accurately using simulation. Also, designers may want more information about the circuit than is available from a single mock-up. For instance, circuit performance is affected by component manufacturing tolerances. In these cases it is common to use SPICE to perform Monte Carlo simulations of

4144-515: The first prototypes. However, prototyping techniques are still used for some applications such as RF circuits, or where software models of components are inexact or incomplete. It is also possible to use a square grid of pairs of holes where one hole per pair connects to its row and the other connects to its column. This same shape can be in a circle with rows and columns each spiraling opposite clockwise/counterclockwise. Source code In computing , source code , or simply code or source ,

4218-482: The holes. Typically the spring clips are rated for 1 ampere at 5 volts and 0.333 amperes at 15 volts (5 watts ). Solderless breadboards connect pin to pin by metal strips inside the breadboard. The layout of a typical solderless breadboard is made up from two types of areas, called strips. Strips consist of interconnected electrical terminals. Often breadboard strips or blocks of one brand have male and female dovetail notches so boards can be clipped together to form

4292-408: The industry standard SPICE 2G6, the last FORTRAN version, released in 1983. SPICE3 was developed by Thomas Quarles (with A. Richard Newton as advisor) in 1989. It is written in C , uses the same netlist syntax, and added X Window System plotting. As an early public domain software program with source code available, SPICE was widely distributed and used. Its ubiquity became such that "to SPICE

4366-475: The instructions can be carried out. After being compiled, the program can be saved as an object file and the loader (part of the operating system) can take this saved file and execute it as a process on the computer hardware. Some programming languages use an interpreter instead of a compiler. An interpreter converts the program into machine code at run time , which makes them 10 to 100 times slower than compiled programming languages. Software quality

4440-461: The large amount of wiring required. The very convenience of easy plugging and unplugging of connections also makes it too easy to accidentally disturb a connection, and the system becomes unreliable. It is possible to prototype systems with thousands of connecting points, but great care must be taken in careful assembly, and such a system becomes unreliable as contact resistance develops over time. At some point, very complex systems must be implemented in

4514-489: The nature of the circuit. The relatively high contact resistance can already be a problem for some DC and very low frequency circuits. Solderless breadboards are further limited by their voltage and current ratings. Solderless breadboards usually cannot accommodate surface-mount technology devices (SMD) or components with grid spacing other than 0.1 inches (2.54 mm). Further, they cannot accommodate components with multiple rows of connectors if these connectors do not match

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4588-529: The netlist for circuit description, but allows analyses to be controlled from a command-line interface similar to the C shell . SPICE3 also added basic X plotting, as UNIX and engineering workstations became common. Vendors and various free software projects have added schematic capture frontends to SPICE, allowing a schematic diagram of the circuit to be drawn and the netlist to be automatically generated and transferred to various SPICE backends. Also, graphical user interfaces were added for selecting

4662-420: The pin rows) is plugged into a breadboard, the pins of one side of the chip are supposed to go into column E while the pins of the other side go into column F on the other side of the notch. The rows are identified by numbers from 1 to as many the breadboard design goes. A full-size terminal breadboard strip typically consists of around 56 to 65 rows of connectors. Together with bus strips on each side this makes up

4736-465: The productivity of computer programmers, the economic value of a code base, effort estimation for projects in development, and the ongoing cost of software maintenance after release. Source code is also used to communicate algorithms between people – e.g., code snippets online or in books. Computer programmers may find it helpful to review existing source code to learn about programming techniques. The sharing of source code between developers

4810-403: The row intended for a supply voltage is marked in red, while the row for ground is marked in blue or black. Some manufacturers connect all terminals in a column. Others just connect groups of, for example, 25 consecutive terminals in a column. The latter design provides a circuit designer with some more control over crosstalk (inductively coupled noise) on the power supply bus. Often the groups in

4884-435: The schematic. Using thumbtacks or small nails as mounting posts was also common. Breadboards have evolved over time with the term now being used for all kinds of prototype electronic devices. For example, US Patent 3,145,483, was filed in 1961 and describes a wooden plate breadboard with mounted springs and other facilities. US Patent 3,496,419, was filed in 1967 and refers to a particular printed circuit board layout as

4958-518: The simulations to be done and manipulating the voltage and current output vectors. In addition, very capable graphing utilities have been added to see waveforms and graphs of parametric dependencies. Several free versions of these extended programs are available. As SPICE generally solves non-linear differential algebraic equations, it may be applied to simulating beyond the electrical realm. Most prominent are thermal simulations , as thermal systems may be described by lumped circuit elements mapping onto

5032-414: The source code. Many IDEs support code analysis tools, which might provide metrics on the clarity and maintainability of the code. Debuggers are tools that often enable programmers to step through execution while keeping track of which source code corresponds to each change of state. Source code files in a high-level programming language must go through a stage of preprocessing into machine code before

5106-417: The springs). Longer stripped wires increase the likelihood of short-circuits on the board. Needle-nose pliers and tweezers are helpful when inserting or removing wires, particularly on crowded boards. Differently colored wires and color-coding discipline are often adhered to for consistency. However, the number of available colors is typically far fewer than the number of signal types or paths. Typically,

5180-454: The transistor level before committing to manufacturing an integrated circuit. The SPICE simulators help to predict the behavior of the IC under different operating conditions, such as different voltage and current levels, temperature variations, and noise. Board-level circuit designs can often be breadboarded for testing. Even with a breadboard, some circuit properties may not be accurate compared to

5254-479: The use of standard models. The standard models today include BSIM3 , BSIM4 , BSIMSOI , PSP , HICUM , and MEXTRAM . Spice can use device models from foundry PDKs . SPICE2 takes a text netlist as input and produces line-printer listings as output, which fits with the computing environment in 1975. These listings are either columns of numbers corresponding to calculated outputs (typically voltages or currents), or line-printer character "plots" . SPICE3 retains

5328-414: The wire ends. Jump wire material for ready-made or homemade wires should usually be 22  AWG (0.33 mm ) solid copper, tin-plated wire - assuming no tiny plugs are to be attached to the wire ends. The wire ends should be stripped 3 ⁄ 16 to 5 ⁄ 16  in (4.8 to 7.9 mm). Shorter stripped wires might result in bad contact with the board's spring clips (insulation being caught in

5402-650: Was developed at the Electronics Research Laboratory of the University of California, Berkeley by Laurence Nagel with direction from his research advisor, Prof. Donald Pederson . SPICE1 is largely a derivative of the CANCER program, which Nagel had worked on under Prof. Ronald Rohrer. CANCER is an acronym for "Computer Analysis of Nonlinear Circuits, Excluding Radiation". At these times many circuit simulators were developed under contracts with

5476-480: Was simultaneous with the compilers needed to translate the source code automatically into machine code that can be directly executed on the computer hardware . Source code is the form of code that is modified directly by humans, typically in a high-level programming language. Object code can be directly executed by the machine and is generated automatically from the source code, often via an intermediate step, assembly language . While object code will only work on

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