Sequential engineering change order under retiming and resynthesis

Engineering change order (ECO) is pivotal in rectifying late design changes that occur commonly due to ever-increasing system complexity. Existing functional ECO methods focus on combinational equivalence assuming a known input correspondence between the old implementation and new specification. They are inadequate for rectifying circuits under sequential transformations. This inadequacy hinders the utilization of powerful and effective sequential optimization methods using retiming and resynthesis. As retiming and/or resynthesis gains increasing adoption in industry, incorporating sequential ECO techniques into the hardware design flow becomes essential. In this paper, we provide the first attempt to extend ECO to designs under retiming and resynthesis in an industrial flow by leveraging conventional combinational ECO engine. Experimental results over industrial ECO benchmarks justify the promising practicality of our methods.