Abstract: Embodiments herein describe an interface between PL fabric and a hardened block that includes a programmable pipeline. This pipeline includes at least a sequential element and a bypass path. For time critical nets in a netlist, the programmable IC routes a net through the sequential element. Doing so mitigates or eliminates the uncertainty associated with routing the net from the hardened block through PL fabric. Also, the sequential element can increase the available time for capturing the data. For less time critical nets, the net can route through the bypass path. This means the route from the hardened block to the PL fabric is determined on the fly by a routing algorithm rather than being fixed.

Abstract: A netlist of a circuit design includes an interface portion and a main portion. The interface portion is decomposed into multiple levels. Each level specifies connections between a respective first set of circuit elements and a respective second set of circuit elements. The second set of circuit elements in each level, except a last level, includes the first set of circuit elements in a next level. The first set of circuit elements identified in a first level of the multiple levels have fixed locations. The second set of circuit elements in the multiple levels is placed-and-routed. The placing-and-routing of the second set of circuit elements in one level is completed before commencing placing-and-routing of the second set of circuit elements in the next level. The main portion is placed-and-routed after placing-and-routing the second set of circuit elements in the multiple levels.