Routing of L-shaped channels, switchboxes and staircases in Manhattan diagonal model

New techniques are presented for routing L-shaped channels, switchboxes and staircases in 2-layer Manhattan-diagonal (MD) model with tracks in horizontal, vertical and +/-45 degrees directions. First, a simple O(l.d) time algorithm is proposed which routes any L-shaped channel with length I, density d and no cyclic vertical constraints, in w (d less than or equal to w less than or equal to d + 1) tracks. Next, an O(l.w) time greedy method for routing an L-shaped channel with cyclic vertical constraints, is described. Then, the switchbox routing problem in MD model is solved elegantly. These techniques easily extendible to routing of staircase channels, yield efficient solutions to detailed routing in general floorplans. Experimental results show significantly low via-count and reduced wire length, thus establishing the superiority of MD-routing over classical strategies.