An algorithm for improving optimal placement for river-routing

Describes a linear-time, terminal-position assignment algorithm that can be used in conjunction with the optimal-placement-for-river-routing algorithm to eliminate, or greatly reduce, the routing area between cells within a module. The terminal-position algorithm that is described, may be used to optimize the positions of the interconnections between the interior rows and columns of cells within a module for custom module generation. The method uses river routing within the cells to virtually eliminate routing channels between the cell rows and columns while producing little or no increase in cell area. Use of this pin assignment algorithm for optimizing the interconnections between custom-synthesized cells provides a significant improvement in area usage