Automated Passive-Transmission-Line Routing Tool for Single-Flux-Quantum Circuits Based on A* Algorithm

We demonstrated an automated passive-transmission-line routing tool for single-flux-quantum (SFQ) circuits The tool is based on the A* algorithm. which is widely used in CMOS LSI design and tuned or microstrip/strip lines formed in the SRL 4-Nb layer structure In large-scale SFQ circuits with 10000-20000 Josephson Junctions, such as microprocessors 80-90% of the wires can be automatically routed in about ten minutes We verified correct operation above 40 GHz. for an automatically routed 4 x 4 switch circuit from on-chip high-speed tests The resulting cretin size and operating. frequency were comparable to those of a manually designed result We believe that the tool is useful for large-scale SFQ circuit design using conventional fabrication processes