Comparison Of Different Types Of Ic Design Computer Science Essay

running(a)y Of Different Types Of Ic visualize Computer Science EssayThe topic of this assignment is to comp atomic number 18 on different types of IC practice. Therefore, we must first understand the meaning of IC. An IC, combine tour of duty, is also cognise as microcircuit, microchip, ti chip, or chip. It is a olive- coatd electronic circuit that lie ins of semiconductor devices and other passive comp acents. These components argon make on a ceramic or plastic container. Internal connections are welded from the chip to different number of external pins depending on the chips bleed.IC innovation means that using logical systemal systemal system and circuit devise techniques to creation and cause integrate circuits. It requires pathways so that information cornerstone flow in good order and lower-ranking electrical components are organized to maximize space so that information bordering system systems faecal matter be as small as attainable. Living in this mod ern age of entropy information, we need to radiation pattern faster and little IC to increase our daily life quality and to catch up with the technology.IC figure is classified mainly into two categories of elonlogic provide and digital IC traffic pattern. digital IC name is the to the highest degree widely apply in daily life such(prenominal) as microprocessor, FPGAs, memories (RAM, ROM, and flash) and digital ASICs. On the other hand, analog IC is use in the soma of sensors, advocator management circuits, and operational amplifiers.The figure of IC is shown below type 1(a) Figure 1(b)(Adapted from introduction to ASIC, http//iroi.seu.edu.cn/books/asics/Book2/CH01/CH01.htm 1)Figure1(a) shows an IC chip where the pins go away fit into holes in a printed-circuit board or breadboard. Figure1(b), the silicon chip ( more properly known as a die) is fitted in the cavity under the fuddled lid.A more detail classification of IC based on digital and analog is as follow Chart 1 vertical classification of ICReferring to chart 1, as we are more arouse in the branch of digital IC design, I expand more on its hierarchy equalize to others. I volition first liken between analog and digital IC design. Then I will explain on the advantages of each of them and mixed- bode IC design. Next, I will compare and explain on full custom and semi-custom IC follow by a simple explanation of silicon compiling as it is not dish antennaussed in lectures. After that, I will compare logic gate array, example mobile phone and PLDs.ContentAnalog, digital and mixed note IC designThe comparison between analog and digital IC design is tabled as below CharacteristicsAnalog IC designDigital IC designNoiseMore susceptible to haphazardnessless(prenominal) ruffle precisenessLess preciseMore preciseDesign difficultyHarder to designEasier to designComplexityHigh unhopefulPower consumption let outHighHeat dissipationLowHighDesign guideDemands strong understanding of the princ iples, c oncepts and techniquesdone by copying and reusing the alike(p) circuit functions or libraryLife cycle10 historic period1 to 2 yearsCostLowHighInformation storageNoise from age degrades information upset-immunity makes information not degradedTable 1 Comparison between analog IC design and digital IC designAnalog IC designIn analog IC design, the analog portends take some(prenominal) value from a given range, and each ludicrous signal value represents different information. It is often entrap in op-amps, analogue regulators, phase locked loops, oscillators and active filters. Therefore, a slight change in the signal may affect the design. For example, an analog signal is used to represent temperature, with one volt representing one degree Celsius. Therefore, 10 volts would stick 10 degrees, and 10.1 volts would produce 10.1 degrees. Analogue IC design produces noise, which is a random disturbance, variation or random thermal vibrations of atomic biticles. Since any changes in an analogue signal is signifi raiset, any disturbance will change in the original signal and appears as noise. As the signal is copied and re-copied, or genetic over ample distances, these random variations become more signifi sack upt and lead to signal degradation. otherwise sources of noise may include external electrical signals or seedy knowing components. These disturbances are reduced by shielding, and using low-noise amplifiers.2 However, some irreducible noise such as the shot noise in components will make an analog IC design imprecise. When designing an analog circuit, the survival of e truly private component, size, posement, and connection is crucial. Every small detail such as the resistance, emplacement and number of resistor, will affect the performance of final exam result. Therefore, designing an analog IC requires strong understanding of the principles, concepts and techniques. Hence, it is said that analog IC design is much more complex compare to digital IC design. It is harder to design because analogue circuit must be designed by hand, and the process is much less automated than digital IC. However, once an analog IC is designed success to the full with high signal to noise ratio, low distortion, low power consumption, high reliability and stability, it can consent a life cycle of more than 10 years. As a result of the long life cycle, the price of analog IC is low.Digital IC designA digital IC is designed to withdraw only input voltages of specific values and it uses only two states which are the binary quantities, on and off representing 1 and 0 or aline and false. This is achieved by using the logic of Boolean algebra. The three basic logic functions in a digital IC are NOT, AND, and OR. A faithfulness table is needed to design a digital IC. As discussed in the lectures, the design of digital systems is divided into combinational systems, which is a representation of a set of logic functions, and sequential syst ems, which are state machines. It is often found in microprocessors, FPGAs, memories (RAM, ROM, and flash) and digital ASIC.Digital IC design produces less noise or even no noise. Digitally represented signals are transmitted using binary sequence of 1 and 0. It can be reconstructed, retransmitted or transmitted over long distance without any error provided the noise during transmission is unable to alter the 1s and 0s. Hence, digital IC is more precise compare to analog IC. Even in a compact disc of around 6 billion binary digits, the information or data can be presented precisely because each digit is handled by the same kind of hardware and in that location is no noise in the manipulation process. Digital IC is easier to design because it is controlled by software such as electronic design automation tools (EDA) so that functions can be neutered without changing the hardware. If pick outrs detect error, they can simply upgrade the software to make better the error. As digita l IC is almost immune to noise, information can be stored and retrieved completely and precisely without any damage or degradation.However, there are some disadvantages of digital IC. Because digital IC is very muffled in circuitry, digital circuits use more energy than analog circuits to extend to the same tasks, thus producing more change. In portable or battery-powered systems this can limit use of digital systems.3 Digital IC emphasizes on speed and cost ratio computing to achieve the lowest possible cost with the highest operating speed. Designers must use more efficient algorithms to process digital signals, or use new process to improve the desegregation cost. Therefore, the life cycle of digital IC is very short, about 1 year -2 years and the cost is higher than analog IC.4 Since digital circuits connote millions of ages as many components as analog circuits, much of the design work is done by copying and reusing the same circuit functions, curiously by using digital design software that contains libraries of pre-structured circuit components. 5 merge signal IC designA mixed-signal integrated circuit is any integrated circuit that has both analog circuits and digital circuits on a single semiconductor die.6 Mixed-signal can be found in ADC or DAC and digital radio chips. Since mixed-signal IC requires both analog and digital design, it is normally designed for a very specific purpose and because of that, their design requires a high level of expertise and careful use of computer back up design (CAD) tools. Therefore this type of design is very complicated andcostly.Full-custom and semi-custom IC designThe comparison between analog and digital IC design is tabled as below CharacteristicsFull-custom IC designSemi-custom IC designCircuitsCustomizedPredesignedManufacturing cartridge holderLongShortPerformanceMaximizeModerateArea of ICMinimizeModerateCostHighLowTable 2 comparison between full-custom and semi-custom IC designFull-custom IC designFu ll-custom design is a methodology for designing integrated circuits by specifying the layout of each mortal transistor, logic electric kiosks, mask layers and the interconnections between them.7 Basically, the IC is designed from scratch and bespoken to meet the requirement of a specific purpose. The main goal of having a full-custom design is to maximize the performance and minimize the field of operation of an IC. Therefore, a drawing card of researches and studies are needed to produce a full-custom IC which results in very high output signal cost and long manufacturing period. Usually, full-custom IC is catered for oversize production so that the high production cost is fully utilized. Full-custom IC is produced from conviction to time when there is no suitable existing libraries available that can be used for the design. This is because existing libraries are outdated or consume too much power.Semi-custom IC designSemi-custom IC design can be partly customized to serve different functions within its general area of application.8 It allows a certain extend of modification during the manufacturing process. It has the diffused layer fully defined but the libraries of pre-structured circuit components with the same circuit functions can be reused. This can save a lot of time and cost to in producing a semi-custom IC design. Therefore, the manufacturing cost if low and it is used widely in almost every IC design around the world. Semi-custom IC design is further classified into 3 groups which are gate array, normal cell and programmable logic devices circuits.Silicon compilation IC designSilicon compilation is to use a software system that takes a users specifications and automatically generates an integrated circuit (IC).9 Generally, a designer is given a description of the system, by using a silicon compiler, mask and test information are produced which is either a simple combinational circuit or a finite state machine. The first step of silicon com pilation is transfer a hardware-description language such as Verilog or VHDL or FpgaC into logic. Next, we shall place the logic gates on the IC followed by routing the standard cells unneurotic to form the desired logic.9 A drawback of this method of IC design is that most of the silicon compilers do not utilize the area of silicon efficiently. Therefore, it is commonly produced in small volume. It may used to generate simple cells to physical body up standard cell libraries.10Gate array, standard cell and programmable logic devices (PLDs) ICThe comparison between gate array, standard cell and programmable logic devices circuits is tabled as below CharacteristicsGate arrayStandard cellPLDs (FPGA) tractabilityFlexibleVery conciliativeLess flexibleRiskLess riskyLess riskyRiskyManufacturing CostModerate trashyExpensiveManufacturing DifficultyModerateEasyVery complexManufacturing timeShortestShortModerateSilicon sizeModerateSmall restrictSpeedSlowModerateFastHeat dissipationLowMod erateHighTable 3 Comparison between gate array, standard cell and PLDs (FPGA) ICGate array ICIn a gate-array-based IC, the transistors, logic gates and other active devices are predefined on the silicon wafer. The only uncompleted part of the creation is the final break through layer, which defines the interconnect between the elements. Connecting these elements allows the function of the IC to be customized. Therefore, it is very flexible and less risky since it uses predefined elements. Furthermore, adding a surface layer of interconnects requires only a small cost and short time to complete. However, the chips designed using gate array techniques are a bit bigger in silicon area than standard cell IC, which makes them more expensive and harder to manufacture.11Standard cell ICIn standard cell IC, different sizes of predesigned cells are used and a big combination of cells can be formed which is known as mega cells. Mega cells can be found in microcontroller or microprocessor. T hese cells, which consist of logic functions such as gates, latches, buffers and flip-flops, are known as standard cell library. Designer only needs to define only the placement of the standard cells and the interconnects in a standard cell IC.12 Standard cell IC is flexible because it uses both digital and analog functions. The transistor sizes can be changed to improve speed and performance. It has a smaller silicon size and therefore a more compact are compare to gate array IC. In addition, it has faster speed which results in higher heat dissipation.(Adapted from Standard-Cell-Based ASICs, http//iroi.seu.edu.cn/books/asics/Book2/CH01/CH01.1.htmpgfId=1331)1Figure 2 shows A cell-based IC die with a single standard-cell area (a flexible block) together with four fixed blocks.Programmable logic devices ICPLD is an electronic component used to build reconfigurable digital circuits an undefined function at the time of manufacture.13 Before starting to implement PLD in a circuit, it mu st be configured or programmed to create a part customized to a specific application. This makes PLD a very flexible design to follow out any custom specification. However, the limited size ((adapted from Programmable Logic Devices, http//iroi.seu.edu.cn/books/asics/Book2/CH01/CH01.1.htm)1Figure 2 shows a PLD die. The macrocells typically consist of programmable array logic followed by a flip-flop or latch. The macrocells are connected using a large programmable interconnect block.