1. A two-dimensional layout of hierarchical routing network comprising a total of a×b blocks with one side of said layout having the size of a blocks and the other side of said layout having the size of b blocks where a≧1 and b≧1, and Said routing network comprising a total of N 1 inlet links and a total of N 2 outlet links and y hierarchical stages wherein either N 2 =N 1 ×d 2 , N 1 =(a×b)×d, and said each block comprising d inlet links and d×d 2 outlet links; or N 1 =N 2 ×d 1 , N 2 =(a×b)×d, and said each block comprising d outlet links and d×d 1 inlet links, and Said each stage comprising a switch of size d×d, where d≧2 and each said switch of size d×d having d incoming links and d outgoing links; and Said incoming links and outgoing links in each switch in said each stage of said each block comprising a plurality of forward connecting links connecting from switches in lower stage to switches in the immediate succeeding higher stage, and also comprising a plurality of backward connecting links connecting from switches in higher stage to switches in the immediate preceding lower stage; and Said forward connecting links comprising a plurality of straight links connecting from a switch in a stage in a block to a switch in another stage in the same block and also comprising a plurality of cross links connecting from a switch in a stage in a block to a switch in another stage in a different block, and Said backward connecting links comprising a plurality of straight links connecting from a switch in a stage in a block to a switch in another stage in the same block and also comprising a plurality of cross links connecting from a switch in a stage in a block to a switch in another stage in a different block.