Library-Based Placement and Routing in FPGAs with Support of Partial Reconfiguration

Abstract

While traditional Field-Programmable Gate Array design flow usually employs fine-grained tile-based placement, modular placement is increasingly required to speed up the large-scale placement and save the synthesis time. Moreover, the commonly used modules can be pre-synthesized and stored in the library for design reuse to significantly save the design, verification time, and development cost. Previous work mainly focuses on modular floorplanning without module placement information. In this article, we propose a library-based placement and routing flow that best utilizes the pre-placed and routed modules from the library to significantly save the execution time while achieving the minimal area-delay product. The flow supports the static and reconfigurable modules at the same time. The modular information is represented in the B*-Tree structure, and the B*-Tree operations are amended together with Simulated Annealing to enable a fast search of the placement space. Different width-height ratios of the modules are exploited to achieve area-delay product optimization. Partial reconfiguration-aware routing using pin-to-wire abutment is proposed to connect the modules after placement. Our placer can reduce the compilation time by 65% on average with 17% area and 8.2% delay overhead compared with the fine-grained results of Versatile Place and Route through the reuse of module information in the library for the base architecture. For other architectures, the area increase ranges from 8.32% to 25.79%, the delay varies from − 13.66% to 19.79%, and the runtime improves by 43.31% to 77.2%.