QFP wiring problem-introduction and analytical considerations

A novel Josephson device with many desirable properties-fast switching speed, high operation frequency, and low power dissipation-has been researched these several years: the Quantum Flux Parametron (QFP). This paper discusses the interconnection problem of QFP circuits, where wire inductance matching and high clock rate restrict the lengths of interconnection wires. A layout model of QFP interconnection wires is clarified, and the effects of wire inductance matching on interconnection area and wire length are analyzed. The limitation comes from the bound of the number of squares of wires, therefore similar effects will exist where wire resistance is bounded. This paper discusses a simple wiring and buffering algorithm for QFP circuits, in which wire inductance is adjusted and the maximum wire length is controlled, to prove that any logic is realizable as a QFP circuit