Reversible logic is one of the stepping stones in low power circuit design. Due to low power consumption and minimum bit loss features, future quantum computing devices are estimated to be reversible. Compared to addition, multiplication is a step further in the ladder of abstraction. It is the manifestation of a pattern generation system capable of representing 3-D patterns and transforming them by rotation, projection, reflection etc. The use of reversible logic in this field can reduce the wastage of energy, power and improve many factors. In this paper, an efficient multiplication algorithm has been proposed which is a modification of conventional shift-and-add multiplication method. Implementing proposed algorithm two reversible multiplier circuit has been proposed. For producing partial product, Peres gate has been used for the first design and Toffoli gate for the second design. Both of the circuits use Peres gate as Half-Adder and HNG gate as Full-Adder for addition of partial products. The first design is improved radically in terms of quantum cost, delay and the second design is notably improved in terms of transistor count and hardware complexity compared to the existing best known multipliers.
Reversible logic is one of the stepping stones in low power circuit design. Due to low power consumption and minimum bit loss features, future quantum computing devices are estimated to be reversible. Compared to addition, multiplication is a step further in the ladder of abstraction. It is the manifestation of a pattern generation system capable of representing 3-D patterns and transforming them by rotation, projection, reflection etc. The use of reversible logic in this field can reduce the wastage of energy, power and improve many factors. In this paper, an efficient multiplication algorithm has been proposed which is a modification of conventional shift-and-add multiplication method. Implementing proposed algorithm two reversible multiplier circuit has been proposed. For producing partial product, Peres gate has been used for the first design and Toffoli gate for the second design. Both of the circuits use Peres gate as Half-Adder and HNG gate as Full-Adder for addition of partial products. The first design is improved radically in terms of quantum cost, delay and the second design is notably improved in terms of transistor count and hardware complexity compared to the existing best known multipliers.
Reversible logic has emerged as a promising computing paradigm having applications in quantum computing, optical computing, dissipation less computing and low power computing etc. In reversible logic there exists a one to one mapping between the input and output vectors. Reversible circuits require constant ancilla inputs for reconfiguration of gate functions and garbage outputs that help in keeping reversibility. Quantum circuits of many qubits are extremely difficult to realize thus reduction in the number of ancilla inputs and the garbage outputs is the primary goal of optimization. In existing literature researchers have proposed several designs of reversible quantum multipliers based on reversible full adders and reversible half adders. The use of reversible full adders and the half adders for the addition of partial products increases the overhead in terms of number of ancilla inputs and number of garbage outputs. This paper presents a binary tree based design methodology for a NxN reversible quantum multiplier. The proposed binary tree based design methodology for NxN reversible quantum multiplier performs the addition of partial products in parallel using the reversible ripple quantum adders with no garbage output and ancilla bit, thereby minimizing the number of ancilla and garbage bits used in the design. The proposed design methodology shows the improvement of 17.86% to 60.34% in terms of ancilla inputs; and 21.43% to 52.17% in terms of garbage outputs compared to all the existing reversible quantum multiplier designs.
Reversible ternary circuit design is now being taken into consideration for its application within the quantum computer and other technologies associated with the nanotechnology domain, in addition to the advantages of the ternary logic application as opposed to binary logic. Multiplier circuit is one of the most important computing circuit in the ALU. Therefore, the circuit optimization for the multiplication will lead to efficient processor. In this paper, the reversible circuit for multiplication of two unsigned two-digit ternary numbers has been proposed. To construct reversible ternary multiplier, a new component termed TPPG with the quantum cost of 13 for partial product generation was proposed. In addition, we have introduced four new blocks of reversible ternary adder with the quantum cost of 11, 10, 7, 5 and one constant input, which can be used in the proposed multiplier circuit. We attempted to optimize the design of the circuits in terms of quantum cost, a number of primitive gates, constant inputs, and garbage outputs as far as possible. To realize all proposed circuits, one-qutrit shift gates and two-qutrit Muthukrishnan-Stroud gates were used.
Programmable reversible logic is emerging as a prospective logic design style for implementation in modern nanotechnology and quantum computing with minimal impact on circuit heat generation. Recent advances in reversible logic using and quantum computer algorithms allow for improved computer architecture and arithmetic logic unit designs. In this paper, a 2*2 Swap gate which is a reduced implementation in terms of quantum cost and delay to the previous Swap gate is presented. Next, a novel 3*3 programmable UPG gate capable of calculating the fundamental logic calculations is presented and verified, and its advantages over the Toffoli and Peres gates are discussed. The UPG is then implemented in a reduced design for calculating n-bit AND, nbit OR and n-bit ZERO calculations. Then, two 3*3 RMUX gates capable of multiplexing two input values with reduced quantum cost and delay compared to the previously existing Fredkin gate is presented and verified. Next, 4*4 reversible gate is presented and verified which is capable of producing the calculations necessary for two-bit comparisons. The UPG and RC are implemented in the design of novel sequential and tree-based comparators. Then, two novel 4*4 reversible logic gates (MRG and PAOG) are proposed with minimal delay, and may be configured to produce a variety of logical calculations on fixed output lines based on programmable select input lines. A 5*5 structure (MG) is proposed that extends the capabilities of both the MRG and PAOG. The comparator designs are verified and its advantages to previous designs are discussed. Then, reversible implementations of ripple-carry, carry-select and Kogge-Stone carry look-ahead adders are analyzed and compared. Next, implementations of the Kogge-Stone adder with sparsity-4, 8 and 16 were designed, verified and compared. The enhanced sparsity-4 Kogge-Stone adder with ripple-carry adders was selected as the best design, and its implemented in the design of a 32-bit arithmetic logic unit is demonstrated. The proposed ALU design is verified and its advantages over the only existing ALU design are quantitatively analyzed.
Abstract Reversible gates have been one of the emerging research areas in these days. The reversible gates have several applications in the fields of low power CMOS, DNA computing, optical, nanotechnology etc. Quantum computing is one of the fastest and upcoming nanotechnologies that can implement the digital logical circuits using reversible logic gates. In this paper, CNOT, TOFFOLI, FREDKIN and PERES reversible logic gates have been implemented on IBM quantum computer. An efficient one-bit full adder is going to be proposed using the reversible gates like CNOT and TOFFOLI. Later, a 4x4 multiplier will be developed using the proposed one-bit full adder. The proposed multiplier is proved to perform faster calculations compared to the earlier multipliers. The simulation of the presented modules will be done on IBM Quantum computer and the respective probabilities can be observed for different inputs.
The power consumption in classical computers has grown to be a critical issue. Thus, quantum computers have become a promising alternative to classical computers for more processing power and lower energy consumption. Reversible gates are important for building the quantum computers. Reversible circuits have various applications, such as digital signal processing, optical computing, quantum computing, etc. The design and synthesis of reversible gates and circuits have grown in popularity and attracted the attention of many researchers. The adder and subtractor are important computation blocks for the structure of the Arithmetic Logic Unit (ALU). In this paper, a design of reversible binary half and full adders and subtractors using reversible logic gates is proposed. The TR (Thapliyal Ranganathan) and Peres gates are used to construct the reversible half adder and subtractor circuit. Meanwhile, the Double Peres Gate (DPG), Fredkin, and NOT gates are used to build the reversible 1-bit full adder and subtractor circuit. The designs are optimized in terms of number of gates, constant inputs, garbage outputs, and quantum cost. The truth table representation and the Binary Decision Diagram (BDD) synthesis method are used to represent and synthesize the circuits, respectively. The circuits are synthesized and simulated using the Verilog Hardware Description Language code and Xilinx ISE 14.7. The results show that the proposed designs achieve the lowest quantum cost in both half adder/subtractor and full adder/subtractor. As the half adder/subtractor has six quantum cost and the full adder/subtractor has nine quantum cost.
Reversible logic is very essential for the construction of low power, low loss computational structures which are very essential for the construction of arithmetic circuits used in quantum computation, nano technology and other low power digital circuits. In this paper two designs of an optimized parallel multiplier circuit using reversible logic gates is presented. Multipliers are very essential for the construction of various computational units of a quantum computer. Duplication of operand bits are achieved using two gates namely BVF gate and CFO gate. The multiplier circuit uses DPG gates and a new 4 X 4 reversible logic gate called PPG gate. The proposed work is best compared to the other existing circuits. Keywords: Reversible logic circuits, Partial products, multiplier, quantum computing, Nanotechnology.