Abstract
Timing prediction and optimization are challenging in design stages prior to detailed routing (DR) due to the unavailability of routing information. Inaccurate timing prediction wastes design effort, hurts circuit performance, and may lead to design failure. This work focuses on timing prediction after clock tree synthesis and placement legalization, which is the earliest opportunity to time and optimize a "complete"netlist. The paper first documents that having "oracle knowledge"of the final post-DR parasitics enables post-global routing (GR) optimization to produce improved final timing outcomes. Machine learning (ML)-based models are proposed to bridge the gap between GR-based parasitic and timing estimation and post-DR results during post-GR optimization. These models show higher accuracy than GR-based timing estimation and, when used during post-GR optimization, show demonstrable improvements in post-DR circuit performance. Results on open 45nm and 130nm enablements using OpenROAD show efficient improvements in post-DR WNS and TNS metrics without increasing congestion.
Original language | English (US) |
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Title of host publication | MLCAD 2022 - Proceedings of the 2022 ACM/IEEE Workshop on Machine Learning for CAD |
Publisher | Association for Computing Machinery, Inc |
Pages | 7-14 |
Number of pages | 8 |
ISBN (Electronic) | 9781450394864 |
DOIs | |
State | Published - Sep 12 2022 |
Event | 4th ACM/IEEE Workshop on Machine Learning for CAD, MLCAD 2022 - Snowbird, United States Duration: Sep 12 2022 → Sep 13 2022 |
Publication series
Name | MLCAD 2022 - Proceedings of the 2022 ACM/IEEE Workshop on Machine Learning for CAD |
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Conference
Conference | 4th ACM/IEEE Workshop on Machine Learning for CAD, MLCAD 2022 |
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Country/Territory | United States |
City | Snowbird |
Period | 9/12/22 → 9/13/22 |
Bibliographical note
Funding Information:This work was supported in part by DARPA HR0011-18-2-0032 (The OpenROAD Project). The work of ABK is also supported in part by NSF CCF-2122665.
Publisher Copyright:
© 2022 ACM.
Keywords
- machine learning
- static timing analysis
- timing optimization