Thermal-Aware Fixed-Outline Floorplanning Using Analytical Models With Thermal-Force Modulation

Abstract

High temperature or temperature nonuniformity has become a serious threat to performance and reliability of high-performance integrated circuits (ICs), which makes the thermal effect turn into a nonignorable issue in the circuit design or the physical design. In order to estimate temperature accurately, the locations of modules have to be determined in advance, which makes an efficient and effective thermal-aware floorplanning play a more important role. Hence, this article proposes a differentiable nonlinear placement model that can optimize temperature and minimize wirelength at the same time without needing to construct a congestion map. In addition, to avoid inducing longer wirelength while optimizing temperature, we propose some techniques, such as thermal-aware clustering, shrink of hot modules, or thermal-force modulation in the multilevel framework. The experimental results demonstrate that temperature and wirelength are greatly improved by our method compared to Corblivar. More importantly, our runtime is quite fast and the fixed-outline constraint can also be satisfied.