A sliced architecture using novel configurable logic modules in quantum dot cellular automata for application of field-programmable gate arrays

Quantum dot cellular automata (QCA) is an emerging transistor-less paradigm with high chip density, ultra-low power and high-speed computation capabilities. Due to programmable design approach, configurable architectures always draw the attention of researchers and manufacturers. Configurable structure has ability to change its functionality even after the product has been formed. This feature makes the circuit suitable for variety of applications. If the configurable circuit is high speed, power aware and nano-size, it drastically improves the performance of high-end complex circuits such as field-programmable gate array (FPGA). Configurable architectures are not much addressed in the QCA. This paper investigates the design and realization of a novel configurable logic module (CLM) in QCA framework. The proposed module is constructed using D flip flop, multiplexer and a programmable block (PB). This module is resilient owing to the efficient design of combinational as well as sequential circuits. The ability and flexibility of the proposed module are further showcased by implementing the high-level circuits such as 2 bit, 3 bit and 4-bit slice architectures for field-programmable gate array (FPGA). The proposed QCA-based 4-bit slice circuit has shown an improvement of 49.77% in cell count and 35.56% in area when compared with one of the equivalent existing circuits. The configurability of the proposed circuit is twofold. Firstly, FPGA itself is the programmable device, and secondly, the proposed module (CLM) which forms the base of FPGA is also programmable. Subsequently, the proposed configurable logic module can be effectively used for the future generation programmable logic devices.