QCA-Based PIPO and SIPO Shift Registers Using Cost-Optimized and Energy-Efficient D Flip Flop

Abstract

With the growing use of quantum-dot cellular automata (QCA) nanotechnology, digital circuits designed at the Nanoscale have a number of advantages over CMOS devices, including the lower utilization of power, increased processing speed of the circuit, and higher density. There are several flip flop designs proposed in the literature with their realization in the QCA technology. However, the majority of these designs suffer from large cell counts, large area utilization, and latency, which leads to the high cost of the circuits. To address this, this work performed a literature survey of the D flip flop (DFF) designs and complex sequential circuits that can be designed from it. A new design of D flip flop was proposed in this work and to assess the performance of the proposed QCA design, an in-depth comparison with existing designs was performed. Further, sequential circuits such as parallel-in-parallel-out (PIPO) and serial-in-parallel-out (SIPO) shift registers were designed using the flip flop design that was put forward. A comprehensive evaluation of the energy dissipation of all presented fundamental flip-flop circuits and other sequential circuits was also performed using the QCAPro tool, and their energy dissipation maps were also obtained. The suggested designs showed lower power dissipation and were cost-efficient, making them suitable for designing higher-power circuits.

Innovation of a Novel Low-Power Modified-GDI QCA-Based Logic Circuit

“…Since QCA cells are linear, they exert a two-phase influence on neighboring cells; a small change in the polarity of one cell leads to a larger change in an adjacent non-polar cell, causing simultaneous reinforcement of both desired and undesired signals. The existing positive feedback leads to stronger polarity and signal injection [28]. However, as also mentioned in [13], this effect is more pronounced in multi-layer circuits and, in general, is neglected in previous works due to the lack of an appropriate noise model in QCA and the suitability of the transmitted signal shape.…”

Design of Cost-Efficient SRAM Cell in Quantum Dot Cellular Automata Technology

“…It provides high operational speed/frequency (in the range of THz) [3,4], high device density [5], and low power dissipation [6]. Therefore, QCA is attracting researchers to design various digital circuits, such as adders, multipliers, multiplexers, encoders, decoders, flip flops, shift registers, content addressable memory, etc., in QCA technology to overcome the issues faced by CMOS [7][8][9][10][11][12][13][14].…”

“…There are four quantum dots in a QCA cell. This is one of the key components of QCA circuits [1,7,8]. Located at the corners of the cell, these quantum dots measure 18 nm by 18 nm.…”

“…A QCA cell has four clock levels to ensure that the signal power is dissipated in the right direction. These are Switch, Hold, Release, and Relax [7,8]. This QCA clocking is depicted in Figure 2.…”

A New Energy-Aware Method for Gas Lift Allocation in IoT-Based Industries Using a Chemical Reaction-Based Optimization Algorithm

“…Oil and gas field planning and development is a complicated process that includes many disciplines and a vast amount of choices, which sometimes overshadows field performance and project economics [13]. A small improvement in quality and productivity can lead to energy savings, waste reduction, time-lost reduction and efficiency increment, which can be achieved using the IoT, IIoT and wireless networks [14][15][16][17].…”