Technology Legalization and Optimization for Adiabatic Quantum-Flux Parametron
Published in IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems, 2024
Adiabatic quantum-flux parametron (AQFP) is an energy-efficient superconducting technology. Before physical design can be performed, AQFP technology mapping involves not only mapping logic into supported gate types but also legalizing the circuit to fulfill the technology-imposed constraints on path balancing and fanout branching by inserting buffer and splitter cells. In this paper, we (a) identify that the AQFP legalization problem is a scheduling problem; (b) propose linear-time depth-optimal scheduling and irredundant buffer insertion algorithms; (c) present heuristic optimization algorithms to further reduce buffer count; and (d) suggest an unsupervised design space exploration approach for AQFP technology mapping.