A line-based parallel memory for QCA implementation

Quantum-dot cellular automata (QCA) has been widely advocated as a new device architecture for nanotechnology. Using QCA, the innovative design of digital systems can be achieved by exploiting the so-called capability of processing-in-wire, i.e., signal manipulation proceeds at the same time as propagation. QCA systems require low power together with the potential for high density and regularity. These features make QCA an attractive technology for manufacturing memories in which the in-wire paradigm can be exploited for storage purposes. This paper proposes a novel parallel memory architecture for QCA implementation. This architecture is based on storing information on a QCA line by changing the direction of signal flow among three clocking zones. Timing of these zones requires two additional clocks to implement a four-step process for reading/writing data to the memory. Its operation has been verified by simulation. It is shown that the requirements for clocking, number of zones, as well as the underlying CMOS circuitry are significantly reduced compared with previous QCA parallel architectures.