Fast and accurate pre-routing timing prediction is essential in the chip design flow. However, existing machine learning (ML)assisted pre-routing timing methods often overlook the impact of power delivery networks (PDNs), which contribute to IR drop and routing congestion. This limitation can make these methods less practical for realworld circuit design flows. To address this, we propose two specialized encoders-an IR drop-aware encoder and a routing congestion-aware encoder-that effectively capture PDN effects through multimodal fusion of netlist, layout, and PDN data. To mitigate the challenges of imbalanced multimodal fusion, we further develop a Pareto optimization approach to ensure balanced utilization of all modalities, enhancing timing prediction accuracy. Comprehensive experiments on large-scale open-source designs using TSMC’s 16 nm technology node validate the superiority of our model over state-of-the-art pre-routing timing prediction methods.

Gate sizing plays an important role in timing optimization after physical design. Existing machine learning-based gate sizing works cannot optimize timing on multiple timing paths simultaneously and neglect the physical constraint on layouts. They cause suboptimal sizing solutions and low-efficiency issues when compared with commercial gate sizing tools. In this work, we propose a learning-driven physically aware gate sizing framework to optimize timing performance on large-scale circuits efficiently. In our gradient descent optimization-based work, for obtaining accurate gradients, a multimodal gate sizing-aware timing model is achieved via learning timing information on multiple timing paths and physical information on multiple-scaled layouts jointly. Then, gradient generation based on the sizing-oriented estimator and adaptive back-propagation are developed to update gate sizes. Our results demonstrate that our work achieves higher-timing performance improvements in a faster way compared with the commercial gate sizing tool.