LMM-IR: Large-Scale Netlist-Aware Multimodal Framework for Static IR-Drop Prediction
Kai Ma, Zhen Wang, Hongquan He, Qi Xu, Tinghuan Chen, Hao Geng
TL;DR
This work tackles the costly, chip-wide static IR drop analysis by proposing LMM-IR, a multimodal, end-to-end framework that fuses circuit-level data with large-scale netlist information. It introduces a 3D point-cloud netlist representation processed by a Large-scale Netlist Transformer (LNT) and pairs it with a circuit encoder, enabling effective cross-modal fusion and accurate IR drop prediction across designs with hundreds of thousands to millions of nodes. A two-stage training regime (reconstruction followed by IR drop prediction) further enhances generalization, yielding state-of-the-art F1 and MAE on ICCAD 2023 benchmarks while maintaining competitive inference times. The approach demonstrates the practical impact of integrating netlist topology and circuit context for robust, scalable PDN analysis, with potential extensions leveraging large language models for text-rich PDN data.
Abstract
Static IR drop analysis is a fundamental and critical task in the field of chip design. Nevertheless, this process can be quite time-consuming, potentially requiring several hours. Moreover, addressing IR drop violations frequently demands iterative analysis, thereby causing the computational burden. Therefore, fast and accurate IR drop prediction is vital for reducing the overall time invested in chip design. In this paper, we firstly propose a novel multimodal approach that efficiently processes SPICE files through large-scale netlist transformer (LNT). Our key innovation is representing and processing netlist topology as 3D point cloud representations, enabling efficient handling of netlist with up to hundreds of thousands to millions nodes. All types of data, including netlist files and image data, are encoded into latent space as features and fed into the model for static voltage drop prediction. This enables the integration of data from multiple modalities for complementary predictions. Experimental results demonstrate that our proposed algorithm can achieve the best F1 score and the lowest MAE among the winning teams of the ICCAD 2023 contest and the state-of-the-art algorithms.
