Patent ID: 7287120
Filing Date: 2007-10-23
Classification: G11C,H04L

Abstract:
1. An associative memory comprising: a first memory incorporating m-pieces of words therein, each word storing a first storage data with n-bit length and a mask information data corresponding to each one or more first storage data, wherein m and n are natural numbers, the mask information data determining whether or not each bit string of the first storage data should be excluded as a retrieval data by setting mask state to be valid or invalid; the first memory comparing an input primary retrieval data with n-bit length with the first storage data for word by word, outputting a primary match signal when the input primary retrieval data and the first storage data are matched, and outputting logical operation results among the matched first storage data as an intermediate data; a compressive operation means for compressing a bit length of the intermediate data to be p-bit length, wherein p is a natural number, to output as a secondary retrieval data; a second memory for storing m-pieces of second storage data with p-bit length in a manner to correspond to each word of the first storage data, the second storage data being derived by compressing the first storage data for word by word; the second memory comparing the secondary retrieval data with the second storage data for word by word and outputting a secondary match signal when the secondary retrieval data and the second storage data are matched; and an invalidation means for altering the secondary match signal corresponding to the primary match signal to be in a mismatch state when a mismatch occurs between each primary match signal output from each word of the first memory.