PROBE2.0: A Systematic Framework for Routability Assessment From Technology to Design in Advanced Nodes

Abstract

In advanced nodes, scaling of critical dimension and pitch has not progressed at historical Moore’s Law rates. Thus, <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">scaling boosters</i> are explored to improve achievable power, performance, area, and cost (PPAC) in new technologies. However, scaling boosters increase complexity of standard-cell architectures, power delivery, design rules, and other aspects of the design enablement, and may not result in design-level benefits. Therefore, design-technology co-optimization (DTCO) methodologies are required to evaluate design-level benefits of scaling boosters. The key challenge for DTCO is that large engineering efforts and long timelines are needed to develop design enablements (e.g., cell libraries) and perform implementation studies in order to assess technology options. We describe a new framework that can systematically evaluate a measure of intrinsic routability, <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$K_{\mathrm{ th}}$ </tex-math></inline-formula> , across both technology and design choices. We focus on routability since it is a critical factor in the scaling of area and cost. Our framework includes realistic standard-cell libraries that are automatically generated using satisfiability modulo theory (SMT) methods, and a new pin shape selection method. Routability assessments are based on the PROBE approach and an improved construction of underlying netlist topologies. Our experimental studies demonstrate the assessment of routability impacts for advanced-node technology and design options. We demonstrate learning-based <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$K_{\mathrm{ th}}$ </tex-math></inline-formula> prediction to reduce runtime, disk space and commercial tool licenses needed to implement our framework. Our work enables faster and more comprehensive evaluation of technology options early in the technology development process.