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 /spl plusmn/45/spl deg/ directions. First, a simple O(l.d) time algorithm is proposed which routes any L-shaped channel with length l, density d and no cyclic vertical constraints, in w (d/spl les/w/spl les/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 the MD model is solved elegantly. These techniques, easily extendible to the 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.