Execution of stored programs by a rapid single-flux-quantum random-access-memory-embedded bit-serial microprocessor using 50-GHz clock frequency.

The article focuses on the development and experimental demonstration of CORE e2h, a rapid single-flux-quantum (RSFQ) bit-serial 8-bit microprocessor with an embedded 128-bit instruction and data memory. CORE e2h employs a minimal reduced instruction set computer (RISC) architecture with 13 instructions and integrates key components such as an arithmetic logic unit, registers, and a program counter on a single chip fabricated using niobium-based Josephson junction technology. The microprocessor successfully executed several stored-program test applications, including integer division and the Euclidean algorithm, with stable operation at around 50 GHz and a measured power consumption of 2.5 mW at 4.2 K, achieving an estimated computing power of 500 million instructions per second (MIPS). These results demonstrate the potential of RSFQ-based microprocessors for high-performance, energy-efficient computing systems operating at cryogenic temperatures.