In this paper, our objective is to design an efficient dedicated squaring architecture in reversible logic using reduced ancillary inputs and zero garbage outputs. The proposed design has a modular structure and has been built recursively. The quantum cost optimization has been achieved using NCV-|1 > and NCV-|v1> and double gate libraries. The performance parameters like ancillary inputs, garbage outputs and quantum cost have been formulated from the design and compared with a very recent work [1].
In this paper, our objective is to design an efficient dedicated squaring architecture in reversible logic using reduced ancillary inputs and zero garbage outputs. The proposed design has a modular structure and has been built recursively. The quantum cost optimization has been achieved using NCV-|1 > and NCV-|v1> and double gate libraries. The performance parameters like ancillary inputs, garbage outputs and quantum cost have been formulated from the design and compared with a very recent work [1].
Digital multipliers are indispensable in Digital signal processing and cryptography. In many mathematical computations, squaring and cubing are frequently used. Generally the multiplier is used in computing square. But the implementation of squaring has the advantage that we can avoid the generation of many partial products used in multipliers by eliminating the redundant bits, thus resulting the circuit to be simpler with less hardware, propagation delay and power consumption. Our work proposes two designs of dedicated squaring techniques in reversible circuits. We use the recursion to achieve our design. The design for n bits is recursively obtained by appending some extra circuitry with the design for (n-1) bits. Our techniques make optimum use of ancillary inputs, garbage outputs and quantum cost and compare favourably with the recent work [1] in this area. Both the designs are having modular structures and can be systemically designed.
Quantum computation is modeled by quantum circuits. All the quantum operations are reversible so the quantum circuits can be built using reversible logic gates. Reversible computing is the emerging technology, its major role is in the field of quantum computing, optical computing, and design of low power nanocircuits. The most frequently used computational unit for digital signal processing and multimedia applications is multiplier. To compute square of an operand, regular multipliers are used in general. This paper proposes a dedicated quantum circuit for computing square of an operand efficiently compared to the existing multipliers in the literature. The squaring unit is mathematically modeled and its metrics quantum cost, garbage outputs and ancilla input, gate count are calculated. We compared the proposed design with the existing multipliers to compute square and found that proposed square unit is efficient in terms of quantum cost, garbage outputs, ancilla inputs and gate count. The proposed reversible square circuit has 63% to 85% improvement of quantum cost, garbage outputs, ancilla inputs and gate count over existing reversible multiplier circuits.
Reversible computing is an emerging field of research and has made remarkable progress. Owing to the reduced energy dissipation in reversible circuits, a lot of research has been done on the design of reversible circuits. In reversible logic circuit designs, along with primary inputs, few constant inputs (Ancilla Inputs) are used to realize required reversible functions. In addition to this, few unused or extra output bits are generated; these bits are named as Garbage Output bits. A challenge in the reversible computation is to use minimum Ancilla Inputs and generate zero Garbage Outputs. In this work, we present designs for addition, subtraction, and addition or subtraction operations. The designs are primarily optimized to achieve zero Garbage Outputs and minimum Ancilla Inputs. In addition, these proposed arithmetic circuits are designed for best Gate Count and Quantum Cost values compared to the existing counterparts.
Background/Objectives: The objective is to reduce the Quantum Cost (QC), Garbage Output (GO) and Gate Counts in the design of the adder by incorporating the Novel Reversible Gates. Methods/Statistical Analysis: In recent day’s energy dissipation is the major complex problem in circuit designing in order to recede this problem the reversible logic is employed, where the input vectors can be derived from the output vectors and from the output vectors the input vectors can be procured. Using this technique the Quantum Cost, Garbage Outputs and Gate Counts of the design is reduced. Findings: Based on the technique of reversible logic a novel reversible Gates is proposed from that the novel reversible adders have been designed. The novel reversible gates satisfy the property of reversibility and universality which shows the uniqueness of the proposed gates. The comparative analysis have been made with the existing work, the proposed work shows a significant improvement in the design optimization parameters. Application/Improvements: The proposed structures can be employed in the ALU design and in Floating Point Multiplier design. The comparative analysis shows that Number of Gates, Garbage Outputs and Quantum Cost is minimum for the proposed gate based structure rather than conventional one Keywords: Garbage Outputs (GO), QCA, Quantum Cost (QC), Reversibility, Reversible Logic, Universality.
In modern Very-Large-Scale Integration (VLSI) technology, managing information loss is a critical challenge. Conventional logic gates, such as AND, OR, and NOT, are prone to data loss during operations, reducing their efficiency for sophisticated applications. Reversible logic gates, which have an equal number of inputs and outputs, offer a solution by preserving data integrity. This paper presents the design and FPGA implementation of an efficient and high-speed full adder circuit utilizing reversible logic gates, namely Feynman, Toffoli, and Peres gates. The design focuses on improving computational efficiency and thermal performance. An analysis of the circuit's quantum cost, garbage outputs, and ancillary inputs reveals its advantages over traditional designs. Proposed design has been realized using Verilog and Synthesize and simulations performed using Xilinx Vivado and Xilinx ISE tools, confirms the functionality and efficiency of the proposed full adder. FPGA implementation of the design has been done using NEXYS A7 (Artix 7 series). The results show that the circuit has a quantum cost of 10, with two garbage outputs and one ancillary input, underscoring its potential for use in low-power, high-performance computing systems and quantum computing applications.
Reversible logic is one of the emerging technologies having promising applications in quantum computing. In this work, we present new design of the reversible BCD adder that has been primarily optimized for the number of ancilla input bits and the number of garbage outputs. The number of ancilla input bits and the garbage outputs is primarily considered as an optimization criteria as it is extremely difficult to realize a quantum computer with many qubits. As the optimization of ancilla input bits and the garbage outputs may degrade the design in terms of the quantum cost and the delay, thus the quantum cost and the delay parameters are also considered for optimization with primary focus towards the optimization of the number of ancilla input bits and the garbage outputs. Firstly, we propose a new design of the reversible ripple carry adder having the input carry Co and is designed with no ancilla input bits. The proposed reversible ripple carry adder design with no ancilla input bits has less quantum cost and the logic depth (delay) compared to its existing counterparts. The existing reversible Peres gate and a new reversible gate called the TR gate is efficiently utilized to improve the quantum cost and the delay of the reversible ripple carry adder. The improved quantum design of the TR gate is also illustrated. Finally, the reversible design of the BCD adder is presented which is based on a 4 bit reversible binary adder to add the BCD number, and finally the conversion of the binary result to the BCD format using a reversible binary to BCD converter.