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The adder topology used in this work are ripple carry adder, carry look ahead adder, carry skip adder, carry select adder, carry increment adder, carry save adder and carry The adder topology used in this work are ripple carry adder, carry look-ahead adder, carry skip adder, carry select adder, carry increment adder, carry save adder and carry bypass adder.

Carry save Adder Carry Save Adder

High speed modified carry save adder using a structure of multiplexers Abstract Adders are the heart of data path circuits for any processor in digital computer and signal processing systems. Growth in technology keeps supporting efficient design of binary adders for high speed applications. In this paper, a fast and area-efficient modified carry save adder (CSA) is presented. A multiplexer based design of full adder is proposed to implement the structure of the CSA. The proposed design of full adder is employed in designing all stages of traditional CSA. By modifying the design of full adder in CSA, the complexity and area of the design can be reduced, resulting in reduced delay time. The VHDL implementations of CSA adders including (the proposed version, traditional CSA, and modified CSAs presented in literature) are simulated using Quartus II synthesis software tool with the altera FPGA EP2C5T144C6 device (Cyclone II). Simulation results of 64-bit adder designs demonstrate the average improvement of 17.75%, 1.60%, and 8.81% respectively for the worst case time, thermal power dissipation and number of FPGA logic elements. Keywords binary adder; carry save adder; high speed; low power; multi operand addition

Full adder to carry save adder.

AbstractThe three-operand binary adder is an essential practical unit to carry out the modular mathematics in numerous cryptography algorithms. The Carry-save adder is mainly used to perform the three-operands addition; however, the propagation delay could be very excessive because of the ripple carry adder present in the carry-save adder. In Han-Carlson adder, the three-operand addition can be accomplished by adding the third operand to the result of the first two operands, but this requires extra hardware. So the area and delays both are simultaneously reduced by the proposed high-speed area-efficient three-operand binary adder. Both the parameters are optimized by replacing the Han-Carlson adder with the Ladner Fischer adder. The proposed architecture is synthesized and implemented with the Xilinx Vivado and Zynq-7000 FPGA family. The Virtual Input-Output (VIO) intellectual prototype concept is used to add three operands, each operand with 32-bit size. The proposed architecture is 1.66 times faster than the Han-Carlson adder with a reduced LUT count. Similar content being viewed by others ReferencesReji SE, Jacob DS (2022) Three—operand binary addition using parallel prefix adders. In: IEEE 19th India council international conference (INDICON). Kochi, India, 2022, pp 1–6. AK, Palisetty R, Ray KC (2020) High-speed area-efficient VLSI architecture of three-operand binary adder. IEEE Trans Circuits Syst I Regul Pap 67(11):3944–3953. MathSciNet Google Scholar Islam MM, Hossain MS, Hasan MK, Shahjalal M, Jang YM (2019) FPGA implementation of high-speed area-efficient processor for elliptic curve point multiplication over prime field. IEEE Access 7:178811–178826Article Google Scholar Liu Z, GroBschadl J, Hu Z, Jarvinen K, Wang H, Verbauwhede I (2017) Elliptic curve cryptography with efficiently computable endomorphisms and its hardware implementations for the Internet of Things. IEEE Trans Comput 66(5):773–785Article MathSciNet Google Scholar Liu Z, Liu D, Zou X (2017) An efficient and flexible hardware implementation of the dual-field elliptic curve cryptographic processor. IEEE Trans Ind Electron 64(3):2353–2362Article Google Scholar Parhami B (2000) Computer arithmetic: algorithms and hardware design. Oxford University Press, New York, NY, USA Google Scholar Download references Author informationAuthors and AffiliationsAnurag University, Hyderabad, Telangana, IndiaGopi Krishna Moodu, G. Srinivasaraju, Amrita Sajja & M. Kiran KumarAuthorsGopi Krishna MooduYou can also search for this author in PubMed Google ScholarG. SrinivasarajuYou can also search for this author in PubMed Google ScholarAmrita SajjaYou can also search for this author in PubMed Google ScholarM. Kiran KumarYou can also search for this author in PubMed Google ScholarCorresponding authorCorrespondence to M. Kiran Kumar . Editor informationEditors and AffiliationsNational Institute of Technology Patna, Patna, Bihar, IndiaPradip Kumar Jain Department of Electrical and Electronics Engineering, Indian Institute of Technology Kanpur, Kanpur, IndiaYatindra Nath Singh Department of Engineering & Technology, University of North Alabama, Florence, SC, USARavi Paul Gollapalli Department of Electronics and Communication Engineering, Mahatma Gandhi Institute of Technology, Gandipet,

A power efficient carry save adder and modified carry save adder

Generator integrated circuits and these have to be connected with logic gates to execute addition operation.The IC for carry lookahead generator is IC 74182 where it accepts Po, P1, P2, and P3 as carry propagate bits inactive low condition and Go, G1, G2, and G3 as carry generate bits and Cn bit as active high input. The active high input pin generates high carriers (Cn+x, Cn+y, Cn+z) at all the stages of binary adders. The pin diagram of the IC is shown below:Pin Diagram of IC 74182 CLAAlso, there is another highly performing adder ICs that integrate carry lookahead adder with a set of full adders. One of these types of IC is 74LS83. It is a 4-bit parallel adder that has four interconnected full adders along with wit CLA circuitry.Ripple Carry Adder V/S Carry Lookahead AdderThere are many factors to be considered to know the difference between carry look ahead adder and ripple adder.Propagation DelayIn the ripple carry adder, the carry bit ripple through every stage in the adder circuit and the time required for the carry bit to propagate from first to last bit is termed as propagation delay. So, the adder requires more time in computing the sum as the carry has to propagate till the last stage.On basis of this, a carry lookahead adder was designed. Here, the sum of all bits that happened at a time without waiting for the previous stage additions.So, CLA has minimum propagation delay when compared with RCA so the performance speed of CLA exceeds RCA. This is because of the correspondingly lesser critical path of CLA than RCA.Dynamic Power DissipationWhen the temperature level is increased, both ripple carry and carry lookahead adders will have an increase in power dissipation at a linear exponential rate. On the other hand, the power dissipation also increased in RCA and CLA when Vdd is increased. From 0.6 V to 1.8 V, the power dissipation rate increases for both high-to-low and low-to-high scenarios.A carry lookahead adder has minimal power dissipation when Vdd lies between 0.6 V to 0.9 V. At the range of 1.8 Volts,. The adder topology used in this work are ripple carry adder, carry look ahead adder, carry skip adder, carry select adder, carry increment adder, carry save adder and carry

Carry Propagation Adder (CPA) and Carry Save Adder (CSA)

M, Mandal N (2018) A novel design of flip-flop circuits using quantum dot cellular automata (QCA). In: 2018 IEEE 8th annual computing and communication workshop and conference (CCWC). IEEE, p 408–414Chudasama A, Sasamal TN (2016) Implementation of 4 × 4 vedic multiplier using carry save adder in quantum-dot cellular automata. In: 2016 international conference on communication and signal processing (ICCSP). IEEE, p 1260–1264De D, Das JC (2017) Design of novel carry save adder using quantum dot-cellular automata. J Comput Sci 22:54–68Article Google Scholar Dysart TJ (2005) Defect properties and design tools for quantum dot cellular automata. MS thesis, Department of Computer Science and Engineering, University of Notre Dame, Notre Dame, INErniyazov S, Jeon J-C (2019) Carry save adder and carry look ahead adder using inverter chain based coplanar QCA full adder for low energy dissipation. Microelectron Eng 211:37–43Article Google Scholar Goswami M, Choudhury MR, Sen B (2019) A realistic configurable level triggered flip-flop in quantum-dot cellular automata. In: International symposium on VLSI design and test. Springer, p 455–467Hema D, Indhumathi B, Ishwarya M, Kumar GH, Balaji GN (2019) Low power and area efficient carry save adder based on static 125 nm CMOS technology. Int J Innov Res Sci Technol 5(8):27–31 Google Scholar Khan A, Mandal S (2019) Robust multiplexer design and analysis using quantum dot cellular automata. Int J Theor Phys 58(3):719–733Article MathSciNet Google Scholar Mosleh M (2019a) A novel design of multiplexer based on nano-scale quantum-dot cellular automata. Concurr Comput Pract Exp 31(13):e5070. Google Scholar Mosleh M (2019b) A novel full adder/subtractor in quantum-dot cellular automata. Int J Theor Phys 58(1):221–246Article Google Scholar Nejad MY, Mosleh M (2017) A review on QCA multiplexer designs. Majlesi J Electr Eng 11(2):69 Google Scholar Pathak N, Kumar S, Misra NK, Bhoi BK (2019) A modular approach for testable conservative reversible multiplexer circuit for nano-electronic confine application. Int Nano Lett 9(4):299–309Article Google Scholar Pudi V, Sridharan K (2011) Low complexity design of ripple carry and Brent–Kung adders in QCA. IEEE Trans Nanotechnol 11(1):105–119Article Google Scholar Rad SK, Heikalabad SR (2017) Reversible flip-flops in quantum-dot cellular automata. Int J Theor Phys 56(9):2990–3004Article Google Scholar

Reversible Ripple Carry Adder b) CARRY SAVE ADDER

To propagate is less.Why is carry look-ahead adder faster?As because of complex hardware in the circuit, the propagation delays get reduced in the circuit. Here, the device calculates either one/more carries in before the addition, where this minimizes the wait time required to calculate the output of higher bits in the adder.What is a 4 bit look ahead carry adder?A 4-bit carry lookahead adder operates by using 4 full adder circuits. Here, the carry bit is not dependent on any of the carry bits at any stage in the circuit. Only the output is based on the bits that are summed up in the preceding stages and on the carry input bit which is provided at the first stage.So, the circuit at any of the stages has no requirement to wait for the carry-bit generation from the past stages and the carry signal can be known at any timestamp.What is the maximum delay in a 64-bit hierarchical carry look-ahead adder?A 64-bit hierarchical carry-lookahead adder will have a delay of 264 = 128 units of time.What is the critical path delay in a 4-bit CLA?In a CLA, the carry bits are known from carry propagate and carry generate where the whole carry bits are present at the time ‘3’. It also takes one more gate delay to know the sum value. So, all the carry and sum bits are present at time ‘4’. With this, the critical path delay for a 4-bit CLA is 4.What bit of CLA’s can be designed?One can design a carry-lookahead adder with 2-bit, 4-bit, 8-bit, 16-bit and others. It is easy to design2-bit carry-lookahead adder truth table and 2-bit carry-lookahead adder circuit diagram4 bit carry-lookahead adder truth table and 4 bit carry-lookahead adder circuit diagram8 bit carry-lookahead adder truth table and 8 bit carry-lookahead adder circuit diagramHow does a 16-bit CLA is constructed?A 16-bit carry lookahead adder can be designed by using 4 4-bit carry lookahead adders. For this, an additional combinational logic circuit is also needed where it generates carry input for every carry-lookahead adder.How many gates are present in a 16-bit CLA?A 16-bit CLA

Carry Skip Adder Using Carry Save Adder Logic

You are here: Home / Digital Electronics / What is Carry Lookahead Adder : Block Diagram & Its WorkingWe all know that in the current day technology everything becomes digitized and digital systems are designed based on fundamental configurations like AND, OR, and NOT gate. These configurations are employed in multiple network designs. Apart from performing logical functionalities, systems should also store up binary numbers and for storage purposes, Flip Flop’s are invented. So, for some functionalities, the combination of Flip Flop’s and logic gates are used, and IC’s (Integrated Circuits) are developed. These integrated circuits are the functional blocks of digital systems and one of the ICs today we are going to discuss is the carry-lookahead adder. This article explains on carry-lookahead adder circuit, its truth table, architecture, used, and benefits.This is a kind of electronics adder that is mainly employed in digital logic. A carry-lookahead adder is also called a fast adder that augments the speed required for determining carry bits. We know that a computer performs its activities through arithmetic operations such as division, addition, multiplication, and subtraction. So, a division is repeated subtraction, and multiplication is repeated addition correspondingly.In order to perform these repeated functions, adder circuits are required and those are half adder, full adder, carry lookahead adder.A carry lookahead adder definition is it is the faster circuit in performing binary addition by using the concepts of Carry Generate and Carry Propagate. A CLA is termed as the successor of a ripple carry adder. A CLA circuit minimizes the propagation delay time through the implementation of complex circuitry.The operation of carry lookahead is based on two scenarios:Calculate every digit position to know whether that position is propagating a carry bit that comes from its right position.Then combine the calculated values to produce the output for every set of digits where the group generates a propagation bit that comes from the right position.Block DiagramCarry lookahead adders operate by generating two bits called Carry Propagate and Carry Generate which are represented by Cp and Cg. The Cp bit gets propagated to the next stage and the Cg

Carry Propagation Adder (CPA) and Carry Save Adder (CSA

W_Cg[1] = i_sum1[1] & i_sum2[1];assign w_Cg[2] = i_sum1[2] & i_sum2[2];assign w_Cg[3] = i_sum1[3] & i_sum2[3];// Creation of carry propogate termsassign w_Cp[0] = i_sum1[0] | i_sum2[0];assign w_Cp[1] = i_sum1[1] | i_sum2[1];assign w_Cp[2] = i_sum1[2] | i_sum2[2];assign w_Cp[3] = i_sum1[3] | i_sum2[3];// Creation of carry termsassign w_C[0] = 1’b0 // no carry input at first stageassign w_C[1] = w_Cg[0] |(w_Cp[0] & w_C[0]);assign w_C[2] = w_Cg[1] |(w_Cp[1] & w_C[1]);assign w_C[3] = w_Cg[2] |(w_Cp[2] & w_C[2]);assign w_C[4] = w_Cg[3] |(w_Cp[3] & w_C[3]);assign result_output = { w_C[4], w_ADD};endmoduleCarry Lookahead Adder Advantages and DisadvantagesThe advantages of CLA are:Carry lookahead adder is considered as the fastest adder when compared with other adder systems.Here, the propagation delay is minimum because the output carry bit is only based on the first carry bit which is applied at the input stage.Using the equations of carry propagate, carry generate and carry bits, CLA devices generate carry-in for every adder in a simultaneous manner.The disadvantages of CLA are:When the number of variables gets increased, the design of carry-lookahead adder becomes more complex.So, when the variables get increased and when CLA is integrated with IC, the area is required to increase.As the hardware is more, the circuitry cost becomes expensive when compared with the ripple carry adder.Please refer to this link to know more about Carry Lookahead Adder MCQsApplicationsThe carry lookahead adder applications are:Carry lookahead adders operating with high speed are employed as integrated circuits so that it is simple to integrate adder in many circuits. Also, the increase in the count of gates is even moderate when implemented for higher bits.When CLA’s are used for high-bit calculations, the device offers more speed whereas the circuit complexity also increases. Usually, these are used for 4-bit modules so that they are integrated together for high-bit computations.On a regular basis, carry-lookahead adders are used in boolean computations.What is the use of carry look-ahead adder?A CLA is a kind of adder that is mainly implemented in digital systems for performing mathematical calculations. A carry lookahead adder enhances the speed of the circuit by lowering the propagation delay which means that the time needed for carry bit. The adder topology used in this work are ripple carry adder, carry look ahead adder, carry skip adder, carry select adder, carry increment adder, carry save adder and carry

Carry save addition - adder - Carry-Save Addition

Bit is used for generating the output carry bit and this is independent of the input carry bit. The below picture shows the 4-bit carry lookahead adder architecture.4-bit Carry Lookahead Adder ArchitectureThe total number of gate levels in the circuit for carry propagation can be known from the full adder circuit. From input Cin to output Cout, two gates are required which are AND and OR gates. As w are considering a 4-bit circuit, the total number of gate levels will be 8. In the same way, for an n-bit parallel adder circuit, there is a 2n number of gate levels.For the construction of carry lookahead adder, we need two Boolean expressions which are for carry lookahead adder formula for carry propagate Cp and carry generate Cg.Cpi = Xi ꚛ YiCgi = Xi . YiWith the above expressions, the sum and carry at the output can be given as:Sumi = Cpi ꚛ CiCi+1 = Cgi + (Cpi . Ci)With the above fundamental equations, the boolean expression for carry output at every stage can be known. SoC1 = Cg0 + (Cp0 . C0)C2 = Cg1 + (Cp1 . C1) = Cg1 + (Cp1 . [Cg0 + (Cp0 . C0)])Cg1 + Cp1 . Cg0 + Cp1 . Cp0 . C0C3 = Cg2 + (Cp2 . C2)Cg2 + (Cp2 . [Cg1 + Cp1 . Cg0 + Cp1 . Cp0 . C0])C4 = Cg3 + (Cp3 . C3)Cg3 + (Cp3 . Cg2 + (Cp2 . [Cg1 + Cp1 . Cg0 + Cp1 . Cp0 . C0])As per the above equations, the carry bit of any stage is based on:Bits those are added in preceding stage and the carry bit that was provided in the initial stage.Based on the C0, C1, C2, and C3 equations, the carry lookahead adder truth table is represented as follows:XYCiCi+1Condition0000Carry generate will not be there001001000111Carry propagate will not be there100010111101Carry generate1111Also, the equations are applied using AND and OR gates which gives the carry lookahead adder circuit diagram.Carry Lookahead Adder Circuit DiagramCarry Lookahead Adder ICsThe CLA’s are combined with many ICs in multiple bit configurations. There exist various individual carry

Schematic of Carry Save Adder

Sadeghi M, Navi K, Dolatshahi M (2019) Novel efficient full adder and full subtractor designs in quantum cellular automata. J Supercomput 76:1–15 Google Scholar Safavi A, Mosleh M (2013) An overview of full adders in QCA technology. Int J Comput Sci Netw Solut 1(4):12–35 Google Scholar Safavi A, Mosleh M (2016) Presenting a new efficient QCA full adder based on suggested MV32 gate. Int J Nanosci Nanotechnol 12(1):55–69 Google Scholar Sandhu A, Gupta S (2019) Performance evaluation of an efficient five-input majority gate design in QCA nanotechnology. Iran J Sci Technol Trans Electr Eng. Google Scholar Seyedi S, Navimipour NJ (2018a) An optimized design of full adder based on nanoscale quantum-dot cellular automata. Optik 158:243–256Article Google Scholar Seyedi S, Navimipour NJ (2018b) Design and evaluation of a new structure for fault-tolerance full-adder based on quantum-dot cellular automata. Nano Commun Netw 16:1–9Article Google Scholar Walus K, Schulhof G (2002) QCADesigner homepage. K, Dysart TJ, Jullien GA, Budiman RA (2004) QCADesigner: A rapid design and simulation tool for quantum-dot cellular automata. IEEE Trans Nanotechnol 3(1):26–31Article Google Scholar Zahmatkesh M, Tabrizchi S, Mohammadyan S, Navi K, Bagherzadeh N (2019) Robust coplanar full adder based on novel inverter in quantum cellular automata. Int J Theor Phys 58(2):639–655Article Google Scholar Download referencesAuthor informationAuthors and AffiliationsDepartment of Computer Engineering, Science and Research Branch, Islamic Azad University, Tehran, IranBehrooz HasaniFuture Technology Research Center, National Yunlin University of Science and Technology, 123 University Road, Section 3, Douliou, Yunlin, 64002, Taiwan, ROCNima Jafari NavimipourAuthorsBehrooz HasaniYou can also search for this author in PubMed Google ScholarNima Jafari NavimipourYou can also search for this author in PubMed Google ScholarCorresponding authorCorrespondence to Nima Jafari Navimipour.Rights and permissionsAbout this articleCite this articleHasani, B., Navimipour, N.J. A New Design of a Carry-Save Adder Based on Quantum-Dot Cellular Automata. Iran J Sci Technol Trans Electr Eng 45, 993–999 (2021). citationReceived: 28 March 2020Accepted: 26 November 2020Published: 05 January 2021Issue Date: September 2021DOI:. The adder topology used in this work are ripple carry adder, carry look ahead adder, carry skip adder, carry select adder, carry increment adder, carry save adder and carry

4-bit Reversible Carry Save Adder with Ripple Carry Adder

AbstractQuantum-dot cellular automata (QCA) technology has been known as an appropriate paradigm for implementing low power consumption digital circuits and different high-performance computations at nanoscale. Considering its nature, this technology has shallow energy losses. Besides, an adder is one of the main parts in the digital circuit designs. Moreover, full adder circuits are the basic units in the digital logic and arithmetic circuits. An emerging three-layer four-bit QCA-based carry-save adder (CSA) circuit is presented in this article. The proposed design offers good performance regarding the delay, area size, and cell number compared to existing ones. The suggested four-bit QCA-based CSA circuit has been depending on a new dedicated QCA full adder circuit. The proposed architectures are simulated with the utilization of the QCADesigner tool version 2.0.3. The outcomes of the simulation have proven that the improved circuit provides a significant development for cell number and area possession compared to previous single-layer and multilayer circuits, and the design leads to around 33.9% improvement in cell number in comparison with the best-presented QCA-based CSA design. Moreover, the proposed CSA architecture utilizes 347 QCA cells. Access this article Log in via an institution Subscribe and save Get 10 units per month Download Article/Chapter or eBook 1 Unit = 1 Article or 1 Chapter Cancel anytime Subscribe now Buy Now Price excludes VAT (USA) Tax calculation will be finalised during checkout. Instant access to the full article PDF. Similar content being viewed by others ReferencesAbbasizadeh A, Mosleh M (2020) Ultradense 2-to-4 decoder in quantum-dot cellular automata technology based on MV32 gate. ETRI J. Google Scholar Abutaleb M (2018) A novel true random number generator based on QCA nanocomputing. Nano Commun Netw 17:14–20Article Google Scholar Ahmad F, Bhat GM, Khademolhosseini H, Azimi S, Angizi S, Navi K (2016) Towards single layer quantum-dot cellular automata adders based on explicit interaction of cells. J Comput Sci 16:8–15Article MathSciNet Google Scholar Bahar AN, Uddin MS, Abdullah-Al-Shafi M, Bhuiyan MMR, Ahmed K (2018) Designing efficient QCA even parity generator circuits with power dissipation analysis. Alex Eng J 57(4):2475–2484Article Google Scholar Chakrabarty R, Mahato DK, Banerjee A, Choudhuri S, Dey