Designing of QCA Schemes by Boundary Functions

A novel universal QCA gate is introduced and called a boundary comparator. This gate implements a Boolean function in its boundary form, as a superposition of elementary boundary functions or as threshold functions having weights equal to integer powers of 2. An array of the boundary comparators is called Comparator based Programmable Array (CPA) and forms a homogeneous regular structure programmable for implementing any logic function. The paper describes a) presenting a Boolean function in its boundary form; b) structure of the boundary comparator, and c) structure of the CPA. The proposed CPA is testable, reparable and debuggable.