Optimal die placement for interposer-based 3D ICs

Sergii Osmolovskyi, Johann Knechtel, Igor L. Markov, Jens Lienig

Abstract: Performance of modern multi-chip modules, increasingly implemented as interposer solutions, is limited by system-level interconnects. We propose an effective method for optimal wirelength-driven die placement of interposer-based 3D ICs. Our key ideas are to leverage the constraint-satisfaction problem (CSP) formalism in combination with a branch-and-bound (B&B) algorithm, and to develop several novel techniques for early identification and pruning of unpromising configurations. Such techniques are crucial for addressing the combinatorial explosion when solving the NP-hard placement problem. Experiments on ISPD08 (modified) and MCNC benchmarks demonstrate that our method outperforms prior art: we can optimally place up to eleven rotatable dies, whereas state-of-the-art tools are limited to six dies.