1. A best match content addressable memory, comprising: a search file memory for storing M file words, each of N-bits in length; a file word register coupled to said search file memory for storing one of said M file words; a match word register coupled to said search file memory for storing a selected one of said M file words as a match word; a search word register for storing a search word of N-bits in length; first means responsively coupled to said file word register and to said search word register for generating a first Hamming distance representation of the file word and the search word; second means responsively coupled to said match word register and to said search word register for generating a second Hamming distance representation of the match word and the search word; comparator means responsively coupled to said first and second means, comparing said first and second Hamming distance representations for transferring said file word into said match word register only if said first Hamming distance is less than said second Hamming distance.