Error correcting scheme
First Claim
1. A method for generating error position indications for use with an error detection and correction scheme in which error syndromes are produced, characterized by hashing each error syndrome by a plurality of hashing functions, using the respective hash outputs to address a plurality of lookup tables, and logically combining the table outputs to generate an error pointer.
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Accused Products
Abstract
A method and an apparatus are disclosed for converting error syndromes of an error-correcting code to pointers which identify the positions of the erroneous bits. Each syndrome is converted by a plurality of hashing functions into a plurality of hash words, which in turn are used to address a plurality of read-only stores. The outputs of the read-only stores are logically combined to obtain the respective error pointer. A preferred embodiment uses three hashing functions (41, 43, 45) and three read-only stores (53, 55, 57) and combines their outputs by an Exclusive-Or function (59). The storage capacity and the processing time required for syndrome-to-error pointer conversion are reduced by the disclosed scheme.
32 Citations
13 Claims
- 1. A method for generating error position indications for use with an error detection and correction scheme in which error syndromes are produced, characterized by hashing each error syndrome by a plurality of hashing functions, using the respective hash outputs to address a plurality of lookup tables, and logically combining the table outputs to generate an error pointer.
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9. Double error correcting apparatus including means for generating an error syndrome, characterized in that it comprises
multiple hashing means connected to the syndrome generator for converting each syndrome to n different hash words, read-only storage means connected to the output of said multiple hashing means to provide n auxiliary words in response to n hash words, and EXCLUSIVE-OR means for logically combining said n auxiliary words into one error pointer.
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13. A method of converting names Ni of a given list of names into associated values Vi of a given list of values, characterized by
converting a selected name by H different hashing functions into H different hash words, converting each of said H hash words by table lookup into an associated auxiliary value, and combining the resulting H auxiliary values by a given logical operation into the single value associated to said selected name.
Specification