Dictionary Machines for Different Models of VLSI

Dictionary machines.are taken as an example to demonstrate the implications the choice of the VLSI hardware model has on the design and analysis of algorithms and special purpose architectures. A systolic search tree and a two-dimensional systolic array are used to implement the dictionary machine. If the wire lengths only affect the area, the systolic search tree suggests itself as an efficient realization of a dictionary machine having constant period, linear areS, and logarithmic execution time for the operations SEARCH, INSERT, DELETE, and XMIN. But as soon as the wire delay is assumed to grow linearly with the wire length, the systolic search tree performs worse than thetuwqdimensional systolic array having constant period, linear area, and execution time proportional to the square root of the capacity of the dictionary machine. Index Terms -Algorithms for VLSI, dictionary machine, systolic array, systolic search tree,, VLSI complexity, VLSI hardware models.