Modeling QCA for area minimization in logic synthesis

Abstract

Concerned by the wall that Moore's Law is expected to hit in the next decade, the integrated circuit community is turning to emerging nanotechnologies for continued device improvements. While significant advancements in nanotechnology devices have been achieved, much work is required to integrate these technologies into the existing design methodologies. Given that the physical design paradigm of each nanotechnology will be significantly different than that of traditional silicon circuits, the underlying cost functions used in optimization algorithms throughout the design abstraction hierarchy must be altered. Because nanotechnologies are not as well developed and understood as silicon devices, abstraction will initially result in less accurate models. However, if models are developed and augmented as nanotechnologies continue to evolve, the transition from CMOS-based design to nano-based design will be relatively seamless. This paper details the logic-level abstraction process for area minimization for one promising nanotechnology -quantum cellular automata (QCA). The model abstracts relative area costs, including interconnect area, for QCA devices, and it is integrated within existing multi-level logic synthesis techniques. Results validate the proposed approach of designing nano-based circuits with the traditional abstraction-based design methodology.

A fault-tolerant design for a digital comparator based on nano-scale quantum-dotcellular automata

“…The inverter can be designed to be inverted by the repulsive Coulomb force when a QCA cell is diagonally organized, as shown in Figure 1(e). In this design, at the diagonal segment of the cell, the repulsive Coulomb force of a cell is inversed (Gergel et al, 2003;Huo et al, 2006;Zhang et al, 2005).…”

Genetic algorithm based logic optimization for multi- output majority gate-based nano-electronic circuits

“…QCA Basic A QCA cell ( Fig. 1) contains four quantum-dots positioned at the corners of a square and two electrons that can move to any quantum-dot within the cell through electron tunneling [1]. Due to Coulombic interactions, as shown in Fig.…”

“…Quantum-dot Cellular Automata (QCA) circuits [1][2][3][4][5][6] are being investigated as a promising nanotechnology that attempts to create general computational functionality by controlling the position of single-electrons. The building blocks of the QCA circuit are the majority-gate and the inverter-gate.…”

Partitioning and placement for buildable QCA circuits

“…A wealth of experiments have been conducted with metal-dot QCA, with individual devices [Amlani et al 1998], logic gates [Snider et al 1999;Amlani et al 1999], wires [Snider et al 1999], latches [Kummamuru et al 2002], and clocked devices [Kummamuru et al 2002]. These advancements have been followed by various recent efforts in developing CAD tools for QCA-based circuits and systems [Gergel et al 2003;Bernstein 2003;Walus et al 2004; J. Huang and Lombardi 2004].…”