Layout parameter analysis in Shannon expansion theorem based on 32 bit adder circuit

In this paper, a hybrid 1-bit adder and 1-bit Subtractor designs are implemented. The hybrid adder circuit is constructed using CMOS (complementary metal oxide semiconductor) logic along with pass transistor logic. The design can be extended 16 and 32 bits lately. The proposed full adder circuit is compared with the existing conventional adders in terms of power, delay and area in order to obtain a better circuit that serves the present day needs of people. The existing 1-bit hybrid adder uses EXNOR logic combined with the transmission gate logic. For a supply voltage of 1.8V the average power consumption (4.1563 µW) which is extremely low with moderately low delay (224 ps) resulting because of the deliberate incorporation of very weak CMOS inverters coupled with strong transmission gates. At 1.2V supply the power and delay were recorded to be 1.17664 µW and 91.3 ps. The design was implemented using 1-bit which can also be extended into a 32-bit design later. The designed implementation offers a better performance in terms of power and speed compared to the existing full adder design styles. The circuits were implemented in DSCH2 and Microwind tools respectively. The parameters such as power, delay, layout area and speed of the proposed circuit design is compared with pass transistor logic, adiabatic logic, transmission gate adder and so on. The circuit is also designed with a decrease in transistors in order to get the better results. Full Subtractor, a combinational digital circuit which performs 1-bit subtraction with borrow in is designed as a part of this project. The main aim behind this part of the project is to design a 1-bit full Subtractor using CMOS technology with reduced number of transistors and hence the efficiency in terms of area, power and speed have been calculated is designed using 8,10,15and 16 transistors. The parameters were calculated in each case and the results have been tabulated.

ABSTRACTThis paper proposed a rail to rail swing, mixed logic style 28-transistor 1-bit full adder circuit which is designed and fabricated using silicon-on-insulator (SOI) substrate with 90 nm gate length technology. The main goal of our design is space application where circuits may be damaged by outer space radiation; so the irradiation-hardened technique such as SOI structure should be used. The circuit’s delay, power and power–delay product (PDP) of our proposed gate diffusion input (GDI)-based adder are HSPICE simulated and compared with other reported high-performance 1-bit adder. The GDI-based 1-bit adder has 21.61% improvement in delay and 18.85% improvement in PDP, over the reported 1-bit adder. However, its power dissipation is larger than that reported with 3.56% increased but is still comparable. The worst case performance of proposed 1-bit adder circuit is also seen to be less sensitive to variations in power supply voltage (VDD) and capacitance load (CL), over a wide range from 0.6 to 1.8 V and 0 to 200 fF, respectively. The proposed and reported 1-bit full adders are all layout designed and wafer fabricated with other circuits/systems together on one chip. The chip measurement and analysis has been done at VDD = 1.2 V, CL = 20 fF, and 200 MHz maximum input signal frequency with temperature of 300 K.

In this paper, comparison of various full adder circuits is analysed. Pull Adder circuits are extensively used in digital design. Here different types of full adder such as Conventional CMOS, based on Ex-OR/Ex-NOR, Pass Transistor Logic(PTL) and Gate Diffusion Input (GDI)technique are done. Prom this, GDI technique takes less number of transistors and therefore consumes less power. In GDI-14T, 12T which is based on MUX and a proposed 10T is implemented. The power consumption is less for 12T whereas better output is obtained for 10T. Simulation results are obtained in 180nm technology using Mentor Graphics Tool.

Addition is an indispensable operation for any high speed digital system, digital signal processing or control system. Therefore, careful optimization of the adder is of the greatest importance. This optimization can be attained in two levels; it can be circuit or logic optimization. In circuit optimization the size of transistors are manipulated, where as in logic optimization the Boolean equations are rearranged (or manipulated) to optimize speed, area and power consumption. In this work technology independent logic optimization is used to design 1-bit full adder with 20 different Boolean expressions and its performance is analyzed in terms of transistor count, delay and power dissipation using Tanner EDA with TSMC MOSIS 250nm technology. All the Boolean expressions are realized in terms of CMOS logic. From the analysis the optimized equation is chosen to construct a full adder circuit in terms of multiplexer. This logic optimized multiplexer based adders are incorporated in selected existing adders like ripple carry adder, carry look-ahead adder, carry skip adder, carry select adder, carry increment adder and carry save adder and its performance is analyzed in terms of area (slices used) and maximum combinational path delay as a function of size. The target FPGA device chosen for the implementation of these adders was Xilinx ISE 12.1 Spartan3E XC3S500-5FG320. Each adder type was implemented with bit sizes of: 8, 16, 32, 64 bits. This variety of sizes will provide with more insight about the performance of each adder in terms of area and delay as a function of size.

Integrated circuit has been widely used in different applications. The design and development of CMOS transistor provides various advantages such as low power dissipation, cost efficient solutions, enhanced processor performance and size reduction. The main aim of the proposed research work is to increase the performance of the processor and reduce the area by increasing the performance of the adder circuits. The adder circuits enable its availability in many processors. In the processor, ALU is considered as the main functional block for performing any arithmetic operations. A novel high performance adders circuits were designed with the 0.18μm technology in TSMC Spice Simulator. Pass transistor logic has been used to reduce the transistors count in the circuit and hence the performance has increased by 10% when compared with the existing CMOS structure.

The adder is the maximum usually used mathematics block in programs inclusive of <span lang="EN-US">central processing unit (CPU) and virtual sign processing. As a result, it is important to expand a space-saving, low-strength, high-overall performance adder circuit. The hassle is diagnosed to layout mathematics sub structures with minimized strength dissipation, low area, and minimal time postpone of common-sense circuits. In conventional <a name="_Hlk95894088"></a>carry select adder (CSA), the time required to generate the sum output is less than other basic adder circuits but the principal difficulty is the location because the variety of transistors used to put in force the CSA circuit is fairly more. So, the area increases because of which the overall power consumption of the circuit will be more. If it's far viable to lessen the variety of transistors used withinside the structure of CSA adder, then, the strength intake of the circuit may be decreased or even the reaction time will improve. By lowering the area of the adder circuit, the suggested solution intends to reduce power consumption and latency.</span>

Performance optimization of the nano-scale carry-skip adder based on quantum dots and its application in the upcoming Internet of Things

Most modern computers use the 2's complement system to represent negative numbers and to perform subtraction by using adder circuit. Several criteria such as speed, power consumption and propagation delay must be taken into account in the design of arithmetic circuits. This study proposed a technique to build an improved 2's complement adder circuit using the combination of existing XOR and new full adder structure. The design is implemented in CEDEC 0.18 µm CMOS process at 3.3v supply voltage. The results showed that the circuit is required only 0.83nW with maximum delay of 50.08 ns for 1-bit adder. Delay and power dissipation of different adder circuits for various numbers of inputs are also simulated and analyzed. Comparison study showed that the design is given a better critical delay and low power dissipation compared to other research studies. Moreover, because of using less number of transistors, the design occupied small die area. The compact size of the circuit with low power and low propagation delay is highly required in arithmetic circuits.

Power consumption plays a major role in high performance, portable devices which are greatly in demand currently. Full adders are the basic building blocks of the arithmetic unit and VLSI applications such as digital signal processing, microprocessor, which are commonly used in these portable devices. Therefore, reducing the power consumption in fuller adder circuits, results in overall power savings of the full circuit. This paper presents a full adder circuit based on multiplexers, which are implemented using different techniques such as pass transistor, transmission gate and Gate Diffusion Input (GDI). The adder circuits implemented, simulated and comparison results are presented. Cadence tool set using 180nm technology is used to obtain the results.

Multiplication is one of the most basic processes, in digital signal processing applications. To process the instructions, most processors require multiplication. Because multipliers are employed in almost all arithmetic operations, they consume the majority of time and power. As a nutshell, the multiplier's efficiency is critical in terms of enhancing processor performance. The array multiplier is one of the most efficient multipliers since it is both quick and simple. However, power consumption is high. The basic components of an array multiplier are adders. The multiplier's efficiency will improve if the adders are much more efficient. The prior study used Complementary Metal Oxide Semiconductor (CMOS) to construct a Quaternary Carry-Lookahead Adder (CLA) that substitutes the adder circuit in the array multiplier. Quaternary number system circuits are quicker than binary number system circuits and can execute arithmetic operations without carry. However, Quaternary circuits take up more space. As a solution, the Quaternary Carry Increment Adder (CIA) is proposed. The proposed adder consumes less power and occupies less area than the existing Quaternary CLA. In the array multiplier, the Quaternary CIA substitutes the Quaternary CLA. This helps to lower the multiplier's power and area consumption. Tanner EDA tool is used to designing the circuits and were simulated with 180 nm technology. Various parameters such as delay, power and power-delay product of the existing and the proposed are measured and compared.

Adders are digital circuits that perform addition operation. There are various types of adder structures such as Ripple carry adder (RCA), carry look ahead adder (CLA) , carry select adder (CSLA) , carry save adder(CSA), carry skip adder, carry increment adder and so on. Again CSLA is of two types that is linear carry select adder (LCSLA) & square root carry select adder (SQRT CSLA). To design an efficient adder circuit in terms of area, power and speed is one of the challenging task in modern VLSI design field. In this paper performance analysis of different adder structures like RCA, CLA, LCSLA and SQRT CSLA has been carried out and then a Heterogeneous adder structure is proposed, which compose of four different sub homogeneous adders (RCA, CLA, LCSLA and SQRT CSLA). The heterogeneous adder structure is used to demonstrate the tradeoffs between the speed and area. In this paper, all adder structures i.e., RCA, CLA, LCSLA and SQRT CSLA are to be designed and are to be compared with each other in terms of delay and area. Then by using the homogeneous adder structures different heterogeneous adder structures of 16-bit size are to be designed. Different heterogeneous adder architectures are compared with each other in terms of delay (ns) and area (number of LUTs). All the adder structures are designed using VHDL with the help of ISE Xilinx design suite 14.2 and functionally simulated using ISIM simulator. All the designs are to be synthesized using Xilinx XST synthesizer.

Objective: The Ultimate aim of the VLSI Design is to improve the efficiency, Reduction of Delay and Power Consumption and to minimize the area. In our proposed approach we had implemented the analysis had been done on the field of Speed, Power consumption, Area and Power delay product (PDP) for a carry skip adder with other adders listed as the parallel prefix adders and others. Methods/Statistical Analysis: The Carry-Skip Adder planned here reduces the time required to propagate the carry by skipping over teams of consecutive adder stages, is understood to be comparable in speed to the carry look-ahead technique whereas it uses less logic space and fewer power. Findings: The adders are basic building blocks of the digital circuits for the Signal processing, Integrating and other process of operation. There are various types of adders are proposed in Literature which are commonly used in VLSI Design. The Simulation results also shows that the proposed adder Architecture is Faster and Area efficient compared to other existing adder architecture. Application/ Improvements: They estimate the performance of proposed design will be better in terms of Logic and route delay by experimental results. Keywords: Adders, Carry Bypass Adder (CBA), Carry Increment Adder (CIA), Carry Look-Ahead Adder (CLA), Carry Skip Adder (CSkA), Han Carlson Adder (HCA), Ripple Carry Adder (RCA)

Quantum-dot cellular automata (QCA) is a novel nanotechnology that promises smaller size, lower power consumption, with faster speed and is considered as a solution to the scaling problems in complementary metal oxide semiconductor technology. We propose a novel QCA F-shaped XOR gate. The proposed gate is simple in structure and powerful in terms of implementing digital circuits. We implement novel adder circuits like half adders and half subtractors by introducing the proposed XOR gate. The proposed adder circuits are simple in design and occupy a fraction of area, as compared to previous designs. These circuits are suitable for optimizing the complex structures. Simulation results demonstrate that the new structures have achieved significant improvements in terms of circuit complexity. The functionality of proposed structures have been checked by QCADesigner tool.

Modular arithmetic computations are used widely in various data security and reliability techniques. Information security systems certainly benefit from the design of energy-efficient modular exponentiation architectures. The use of low-power logic adders to realize modular exponentiation operations is very essential in prospective cryptography contexts. In this paper, various full adder circuit designs are presented which are used in developing an energy efficient modular exponentiation architecture. Here, the full adder is designed using Register Transfer Level (RTL), Standard Logic Cell (SLC), Reversible Logic Gate (RLG), and Artificial Neural Network (ANN) logic methods. All full adder designs are imposed on modular exponentiation circuit to analyze performance metrics in terms of dynamic power dissipation, Figure of Merit, and Energy Delay Product. The Modular Exponentiation architecture is designed based on the above full adders and is simulated and synthesized using Xilinx Vivado Zynq-7000 family configurable device. From the synthesis results, the dynamic power dissipation, Figure of Merit (FOM), and Energy Delay Product (EDP) of the ANN Modular Exponentiation circuit shows an improvement compared to other designs. The total power consumption, dynamic power dissipation, FOM, and EDP of ANN Full Adder and Modular Exponentiation circuit can achieve (8%, 16%), (23.5%, 20.7%), (14.7%, 14%), and (28.5%, 16%) compared to RLG Full adder and Modular Exponentiation circuit.KeywordsFeynman gateMLPerceptronSwitching activityPDPModular multiplierToffoli gate

Pass Transistor Logic (PTL) has attracted more and more interest during recent years, since it has proved to be an attractive alternative to static CMOS designs with respect to area, performance and power consumption. Existing automatic PTL synthesis tools use a direct mapping of (decomposed) BDDs to pass transistors. Thereby, structural properties of BDDs like the ordering restriction and the fact that the select signals of the multiplexers (corresponding to BDD nodes) directly depend on input variables, are imposed on PTL circuits although they are not necessary for PTL synthesis. General multiplexer circuits can be used instead and should provide a much higher potential for optimization compared to a pure BDD approach. Nevertheless-to the best of our knowledge-an optimization of general Multiplexer Circuits (MCs) for PTL synthesis has not been tried so far due to a lack of suitable optimization approaches. In this paper we present such an algorithm which is based on efficient BDD optimization techniques. Our experiments prove that there is indeed a high optimization potential by the use of general MCs-both concerning area and depth of the resulting PTL networks.