Fast Random and Sequential Access to Dynamic Memories of Any Size

Aho and Ullman have proposed an access mechanism for dynamic memories by which each item of a block after the first two can be accessed in a single step. Recently, this organization has been enhanced by Stone, whose memory scheme allows, on the average, random access in 1.5 log2 n steps; whereas, in the case of a sequential access, a single step is required for each item after the first. However, both methods can only be used for memories of size n = 2k - 1. We generalize Stone's technique in order to eliminate this severe restriction. The very large number of solutions that can be obtained for each memory size implies that an optimization procedure is valuable if the cost constraints of a particular implementation are known.