Combining Technology Mapping with Layout

Due to the significant contribution of interconnect to the area and speed of today’s circuits and the technological trend toward smaller and faster gates which will make the effects of interconnect even more substantial, interconnect optimization must be performed during all phases of the design. The premise of this paper is that by increasing the interaction between logic synthesis and physical design, circuits with smaller area and interconnection length, and improved performance and routability can be obtained compared to when the two processes are done separately. In particular, this paper describes an integrated approach to technology mapping and physical design which finds solutions in both domains of design representation simultaneously and interactively. The two processes are performed in lockstep: technology mapping takes advantage of detailed information about the interconnect delays and the layout cost of various optimization alternatives; placement itself is guided by the evolving logic structure and accurate path-based delay traces. Using these techniques, circuits with smaller area and higher performance have been synthesized.