Constraint-Based Placement and Routing for FPGAs Using Self-Organizing Maps

Field-programmable gate arrays (FPGAs) are becoming increasingly popular due to low design times, easy testing and implementation procedures and low costs. FPGAs placement and routing are NP-complete problems dealt well with modern tools using heuristic algorithms. As modern FPGAs increase in size and also new capabilities, such as run-time reconfiguration (RTR), are introduced, the complexity of these problems is greatly increased. In this paper we approach both problems using a modified version of Kohonen self-organizing map. The algorithm, consisting of four phases, takes into consideration constraints that may apply to the FPGA design (such as I/O pins, resource constraints like global clock etc). The modified algorithm yields a good topological map of the design to be placed, minimizing the average distance between connecting logic blocks.