Error control arrangement for associative information storage and retrieval

Claim 2

Apparatus for providing error control for associative information storage and retrieval comprising storage means for storing a plurality of data key words and a plurality of groups of data, each of said groups being associated with a data key word, each of said data key words being encoded in a burst error correcting code, means for comparing each data key word retrieved from said storage means with a master key word similarly encoded in said error correcting code, and means responsive to said comparing means for indicating, for each pair of words compared, whether the pattern of differing digits corresponds to an error pattern which is correctable by said error correcting code.

Claim 3

Apparatus as in claim 1 further comprising means responsive to an indication from said indicating means that a pattern of differing digits corresponds to an error pattern which is correctable by said error correcting code for enabling the retrieval from or replacement in said storage means of the group of data associated with the data key word of said each pair.

Claim 4

Apparatus as in claim 2 wherein said error correcting code is an m-bit-burst error correcting code and said indicating means includes means responsive to said comparing means for signalizing, for said each pair of words compared, whether m exceeds or is equal to the span length s of digit positions having differing digits.

Claim 5

Apparatus as in claim 3 wherein said enabling means includes means responsive to said signalizing means signalizing that m exceeds or is equal to s for enabling the retrieval from or replacement in said storage means of the group of data associated with the data key word of said each pair.

Claim 6

Apparatus as in claim 4 wherein said comparing means includes an EXCLUSIVE-OR gate for generating a logical ''''1'''' signal for each pair of differing bits applied thereto and for generating a logical ''''0'''' signal for each pair of like bits applied thereto.

Claim 7

Apparatus as in claim 5 wherein said signalizing means includes a counter responsive to the first logical ''''1'''' signal generated for a certain pair of words compared for counting each pair of bits of said certain pair thereafter applied to said EXCLUSIVE-OR gate up to a count of m-1, and means responsive to the logical ''''1'''' signal generated next following occurrence of said counter reaching a count of m-1 for indicating that s exceeds m.

Claim 8

An error control method for associative information storage and retrieval comprising storing a plurality of data key words and a plurality of groups of data in a storage device, each of said groups being associated with a data key word, each of said data key words being encoded in a burst error correcting code retrieving a data key word from said storage device comparing said retrieved key data word with a master key word similarly encoded in said error correcting code, and generating a signal if, for the words compared, the pattern of differing digits corresponds to an error pattern which is correctable by said error correcting code.

Claim 9

An error control method for associative information storage and retrieval comprising storing a plurality of data key words and a plurality of groups of data in a storage device, each of said groups being associated with a data key word, each of said data key words being encoded in a burst error correcting code retrieving a data key word from said storage device comparing said retrieved key data word with a master key word similarly encoded in said error correcting code, and generating a signal if, for the words compared, the pattern of differing digits corresponds to an error pattern which is correctable by said error correcting code.

Claim 10

A method as in claim 7 further comprising retrieving from or replacing in said storage device the group of data associated with the retrieved data key word in response to said signal.

Claim 11

Apparatus for facilitating a search of groups of data words in a sequential storage device on the basis of a key word, encoded in a burst error correcting code, in each group of data in which a mismatch between a master key word and the stored key word is determined by the time the key word is read out of the storage device comprising: a counter for counting bits read from a storage device; a controller for storing a master key word; a comparator for detecting a mismatch between a bit in the key word from the storage device and a bit in the master key word from said controller; counter control means for enabling said counter in response to said comparator detecting a bit mismatch; span logic means responsive to said counter reaching a predetermined count for generating a signal indicative thereof; mismatch logic means, responsive to said span logic means and said comparator, for generating a key word mismatch signal when a bit mismatch occurs after the predetermined count.

Claim 12

Apparatus for facilitating a search of groups of data words in a sequential storage device on the basis of a key word, encoded in a burst error correcting code, in each group of data in which a mismatch between a master key word and the stored key word is determined by the time the key word is read out of the storage device comprising: a counter for counting bits read from a storage device; a controller for storing a master key word; a comparator for detecting a mismatch between a bit in the key word from the storage device and a bit in the master key word from said controller; counter control means for enabling said counter in response to said comparator detecting a bit mismatch; span logic means responsive to said counter reaching a predetermined count for generating a signal indicative thereof; mismatch logic means, responsive to said span logic means and said comparator, for generating a key word mismatch signal when a bit mismatch occurs after the predetermined count.