The design automation community has been actively exploring machine learning (ML) for very-large-scale-integrated (VLSI) computer-aided design (CAD). Many studies have explored learning-based techniques for cross-stage prediction tasks in the design flow. Although building ML models usually requires a large amount of data, most studies can only generate small internal datasets for validation due to the lack of large public datasets. Such a situation challenges the research in this field and raises potential issues like difficulty in benchmarking and reproducing results, limited research scope on small internal datasets, and high bar for new researchers. Therefore, in this article, we present an open-source dataset called “CircuitNet” for ML tasks in VLSI CAD. The dataset consists of more than 10K samples extracted from versatile runs of commercial design tools based on six open-source RISC-V designs which support typical cross-stage prediction tasks, such as routability and IR drop prediction, with extensive benchmarking on recent models. With the dataset prepared, we identify two practical challenges, data imbalance and model transferability, for ML application in CAD. To overcome data imbalance, we propose a loss function, biased loss, to give more weight to the minority, leading to 2% congestion reduction in routability-driven placement. We test the model transferability from RISC-V designs to ISPD 2015 contest designs in congestion prediction with several transfer learning methods and further proposed a knowledge distillation-based transfer learning framework with up to 20% accuracy improvement. We believe this dataset can open up new opportunities for ML in CAD research and beyond.

Accurate and efficient power analysis at early VLSI design stages is critical for effective power optimization. It is a promising yet challenging task to model the circuit power at early design stages, especially during placement with the clock tree and final signal routing unavailable. Additionally, optimization-induced circuit transformations like circuit restructuring and gate sizing can invalidate fine-grained power supervision. Addressing these difficulties, we introduce the first circuit-transformation-aware power prediction model at placement stage with robust generalization capabilities. Our technology includes a dedicated clock tree model and an innovative train-and-calibrate scheme that effectively integrates topological and layout features. Compared to the cutting-edge commercial IC engine Innovus, we have significantly reduced the cross-stage power analysis error between placement and detailed routing.

IR drop on the power delivery network (PDN) is closely related to PDN’s configuration and cell current consumption. As the integrated circuit (IC) design is growing larger, dynamic IR drop simulation becomes computationally unaffordable and machine learning based IR drop prediction has been explored as a promising solution. Although CNN-based methods have been adapted to IR drop prediction task in several works, the shortcomings of overlooking PDN configuration is non-negligible. In this paper, we consider not only how to properly represent cell-PDN relation, but also how to model IR drop following its physical nature in the feature aggregation procedure. Thus, we propose a novel graph structure, PDNGraph, to unify the representations of the PDN structure and the fine-grained cell-PDN relation. We further propose a dual-branch heterogeneous network, PDNNet, incorporating two parallel GNN-CNN branches to favorably capture the above features during the learning process. Several key designs are presented to make the dynamic IR drop prediction highly effective and interpretable. We are the first work to apply graph structure to deep-learning based dynamic IR drop prediction method. Experiments show that PDNNet outperforms the state-of-the-art CNN-based methods and achieves 545× speedup compared to the commercial tool, which demonstrates the superiority of our method.

As semiconductor technology continues to scale, power consumption has become a primary focus of researchers and engineers. In particular, cross-PVT (Process, Voltage, and Temperature) full-chip leakage power estimation is urgently necessary, as it provides crucial guidance for power delivery network design and low-power design strategies and ensures efficient chip design. To address this challenge, we propose a Artificial Neural Network (ANN) model that efficiently integrates data from multiple PVT and provides accurate estimation, given the limited data available for training. This approach enables full-chip leakage power estimation using only one critical cell at one operating state. Our method has been validated using data from a 14 nm industrial FinFET technology node. Compared to the traditional simulation-based method, our method can achieve around 1.76% relative error on average and largely reduced turnaround time, considering all cell types and states. In this case, our method outperforms previous leakage power estimation techniques which fail to provide accurate estimation in low temperature range. When focusing solely on one type of critical cell, the method delivers further acceleration, while maintaining 8.5% maximum relative error.