Patent ID: 6389524
Filing Date: 2002-05-14
Classification: G06F,G11C

Abstract:
An associative memory device outputting data according to an input of retrieval data having a plurality of bits, comprising:a keyword comparison array retaining a plurality of tag data each having a plurality of bits and performing matching between said retrieval data input and each of said plurality of tag data, said keyword comparison array including a plurality of matching circuits provided corresponding to said plurality of tag data, each for comparing said retrieval data and corresponding one of said plurality of tag data, each of said plurality of matching circuits having n (n is an integer at least 0) first comparison memory units provided corresponding to n bits of said corresponding tag data, each retaining corresponding one of said n bits and performing a matching operation between the retaining bit and a corresponding bit of said retrieval data, and m (m is a natural number) second comparison memory units provided corresponding to a plurality of parts each including at least one bit of remaining bits of said corresponding tag data other than said n bits, each performing said matching operation between the at least one bit of corresponding one of said plurality of parts of the remaining bits and corresponding at least one bit of said retrieval data, a matching result of which being invalidated dependent on an externally set comparison condition signal, said keyword comparison array further including a plurality of matching detection signal lines provided corresponding to said plurality of matching circuits, each of said plurality of matching detection signal lines having a potential level determined according to the matching results of said n first comparison memory units and the matching results of (mâˆ’k) (k is an integer from 0 to m) out of said m second comparison units other than the k units having said comparison results invalidated, included in corresponding said matching circuit; and a data storage array responsive to the potential level of each of said plurality of matching detection signal lines for outputting data corresponding to one of said plurality of tag data that matches said retrieval data.