Machine Learning-Based Hard/Soft Logic Trade-offs in VTR

Ritwik Sinha, Seyed Alireza Damghani, Kenneth B. Kent

Abstract: Circuit optimization, in any application, is of high importance since it not only improves the efficiency of the intended purpose but also enhances the quality of the final product. It enables the circuit designer to cater to the specific needs of the customer. For circuit optimization to occur, we need to elaborate these circuits on a primary level and perform synthesis operations. Previous research shows that the investigation of improvements to different Hardware Description Language (HDL) elaboration phases, was completely closed source. Verilog To Routing (VTR) is an open-source Electronic Design Automation (EDA) tool. ODIN II is the VTR synthesizer that parses the input Verilog, elaborates its Abstract Syntax Tree (AST), performs the partial mapping according to the architecture file, and performs optimizations such as unused logic removal. To that end, the hard versus soft logic trade-off aims to optimize the performance of the circuit. This project focuses on using machine learning approaches to make synthesis tools intelligent enough to decide this ratio on their own, without the need for human intervention, and based on some predefined criteria. This paper discusses the criteria for having less latency or less critical path delay in the circuit. Also, it aims at providing this level of intelligence at an earlier stage in the VTR pipeline to make better use of this information.