🤖 AI Summary
This work addresses the limitations of existing approaches for simulating oscillator-based Ising/Potts machines—namely, low coupling precision, process sensitivity, poor scalability in analog designs, and high energy consumption with irregular memory access in digital platforms—by proposing a co-designed algorithm-hardware architecture implemented as a custom ASIC. Leveraging a fixed-point Kuramoto model, the architecture efficiently emulates Ising/Potts dynamics through a directly connected array of processing units interconnected via a king’s graph topology, thereby eliminating shared-memory bottlenecks and circumventing the memory wall while retaining programmability. A 20×20 prototype chip achieves solution accuracies of 97%–100% on Max-Cut and graph coloring benchmarks, significantly outperforming general-purpose platforms in both energy efficiency and solution speed.
📝 Abstract
Oscillator-based Ising/Potts machines (OIMs/OPMs) are promising hardware accelerators for NP-hard combinatorial optimization problems using coupled oscillator synchronization dynamics. Analog OIMs/OPMs offer speed advantages but have limited coupling resolution, process variation susceptibility, and scalability issues, while digital GPU/CPU emulations provide flexibility but suffer from irregular memory access patterns and energy inefficiency. This work presents a custom ASIC architecture that digitally emulates OIM/OPM dynamics using simplified fixedpoint Kuramoto model equations. The scalable design features processing elements with direct interconnections, eliminating shared memory bottleneck while maintaining digital programmability and precision. A 20x20 processing element array with king's graph connectivity is prototyped and evaluated via post-layout simulations on unweighted/weighted max-cut and graph coloring problems, achieving 97-100% maximum accuracy with significant speed and energy improvements over general-purpose platforms, demonstrating the viability of algorithmically codesigned ASICs.