Abstract: A dynamic memory is disclosed, in which data is rearranged among its internal memory locations in accordance with either of two different shuffle operations. The shuffle operations, an In Shuffle and an Out Shuffle, rearrange the data in a manner similar to the manner in which cards of a deck are rearranged when shuffled. Using only the two shuffle operations, a method of random accessing data in the theoretical minimum time is disclosed, for all odd-sized memories and all memories of size 2.sup.r. Once a desired datum has been accessed, successive data can be sequentially accessed in unit time. Processes for sequential accessing of data are shown to be related to the existence of sequences of In and Out Shuffles which move each datum through the read/write window of the memory, which sequences are defined as tours. A method for determining the existence of and for constructing tours for certain sized memories is also disclosed.
Type:
Grant
Filed:
November 8, 1977
Date of Patent:
July 10, 1979
Assignee:
United States of America, Director National Security Agency
Inventors:
S. Brent Morris, Arthur Valliere, III, Richard A. Wisniewski