Process variations and device aging impose profound challenges for circuit designers. Without a precise understanding of the impact of variations on the delay of circuit paths, guardbands, which keep timing violations at bay, cannot be correctly estimated. This problem is exacerbated for advanced technology nodes, where transistor dimensions reach atomic levels and established margins are severely constrained. Hence, traditional worst-case analysis becomes impractical, resulting in intolerable performance overheads. Contrarily, process-variation/aging-aware static timing analysis (STA) equips designers with accurate statistical delay distributions. Timing guardbands that are small, yet sufficient, can then be effectively estimated. However, such analysis is costly as it requires intensive Monte-Carlo simulations. Further, it necessitates access to confidential physics-based aging models to generate the standard-cell libraries required for STA. In this work, we employ graph neural networks (GNNs) to accurately estimate the impact of process variations and device aging on the delay of any path within a circuit. Our proposed GNN4REL framework empowers designers to perform rapid and accurate reliability estimations without accessing transistor models, standard-cell libraries, or even STA; these components are all incorporated into the GNN model via training by the foundry. Specifically, GNN4REL is trained on a FinFET technology model that is calibrated against industrial 14nm measurement data. Through our extensive experiments on EPFL and ITC-99 benchmarks, as well as RISC-V processors, we successfully estimate delay degradations of all paths -- notably within seconds -- with a mean absolute error down to 0.01 percentage points.
翻译:工艺变异和装置老化给电路设计师带来了深刻的挑战。 如果不能准确理解变异对路路路延迟的影响, 就无法准确估计安全带(这种变异使时间偏差处于偏差状态)的影响。 这个问题对于先进技术节点(晶体管尺寸达到原子水平,固定边距严重受限)来说更加严重。 因此,传统的最坏情况分析变得不切实际,导致无法容忍的性能间接费用。 相反, 流程变换/对静态时间分析(STA)让设计师掌握准确的统计延迟分布。 然后,可以有效地估计出小型但足够且足够多的警戒带。 然而,这种分析成本高昂,因为它需要强化蒙特-卡洛模拟。 此外,为了建立基于晶体的保密物理成形模型,需要为STA建立必要的标准细胞图书馆。 在这项工作中,我们使用图形神经网络(GNNN)来准确估计流程变异的影响,并设置任何电路路程的延迟。 我们提议的所有GNNNN4REL框架都授权设计师进行快速和准确的准确的估算,而无需通过流算模型进行快速的测算。