Formal description of the functional behavior of RSFQ logic circuits for design and optimization purposes

For being used in the design of Rapid Single Flux Quantum (RSFQ) circuits in a multipurpose manner, we developed a systematic and consistent approach for modeling the nominal circuit behavior using hardware description languages. We are presenting a method for establishing evaluation criteria for the circuit´s behavior which can directly be used in the input for circuit simulation and serve as a behavioral reference in yield-driven optimization cycles. Furthermore, this behavioral modeling technique allows for mixed-mode simulation with its advantages of both analysis speed-up and error localization. Finally, we demonstrate the application in high-level circuit synthesis which will be necessary to manage complex design problems.