| Obstacle-avoiding rectilinear Steiner minimal tree (OARSMT) construction is becoming one of the most sought after problems in modern design flow. In this thesis we present an algorithm to route a multi-terminal net in the presence of obstacles. Ours is a top down approach which includes partitioning the initial solution into subproblems and using obstacle aware version of Fast Lookup Table based Wirelength Estimation (OA-FLUTE) at a lower level to generate an OAST followed by recombining them with some backend refinement. To construct an initial connectivity graph we use a novel obstacle-avoiding spanning graph (OASG) algorithm which is a generalization of Zhou's spanning graph algorithm without obstacle [18]. The runtime complexity of our algorithm is O(n log n). Our experimental results indicate that it outperforms Lin et al. [9] by 2.3% in wirelength. It also has 20% faster run time as compared with Long et al. [11], which is the fastest solution till date. |
