COMPUTER ARCHITECTURE ISSUES IN SUPERCONDUCTIVE MICROPROCESSORS

The prospect of picosecond gate delays, combined with the peculiarities of superconductive digital circuits, pushes system architecture design for superconductive microprocessors onto new ground. Several groups have proposed possible architectures, including systems for the quantum flux parametron, for modified variable threshold circuits, and for rapid single flux quantum devices. These architectures are representative of systems that are, respectively, synchronous on the gate level, synchronous with ripple logic capability, and asynchronous, and thus span a large range of possible solutions. This paper reviews these architectures and discusses some important issues in choosing an architecture compatible with superconductive digital circuit technology.