An RTL-to-GDSII Flow for Single Flux Quantum Circuits Based on an Industrial EDA Toolchain

Josephson Junction-based superconducting circuits are promising candidates for high-speed digital electronics with dramatically lower power consumption than CMOS, as well as a potential enabler towards the implementation of large-scale quantum computing. In this paper, we will describe an automated flow for the creation of microcontrollers and other digital systems in the single flux quantum (SFQ) technology. Starting with a register-transfer level (RTL) description of the circuit, the flow integrates logic synthesis, technology mapping, timing and logic verification, library cell placement and routing, and completes with a candidate physical design for fabrication. The flow makes use of the same tools employed in leading-edge CMOS. We will examine the challenges specific to the SFQ technology at the different stages in this flow. We will also report on metrics to qualify the resulting physical layout, such as circuit density and timing results.