公开(公告)号：FR2823035A1

公开(公告)日：2002-10-04

申请号：FR0104508

申请日：2001-04-03

Applicant: ST MICROELECTRONICS SA

Inventor： MURILLO LAURENT ,  RICODEAU FRANCOIS

IPC: H03M13/19 ,  H03M13/00 ,  G06F11/10

Abstract: The method for determining r error-detection bits which can be associated with a word of m bits for encoding, comprises a step of producing a vector of m components representative of the word of m bits and a parity-control matrix (M) of dimension rxm. The parity-control matrix (M) is such that each column of the matrix comprises an odd number of digit 1, where the number is greater than or equal to three. The last r-3 elements of each column of the matrix make part of a submatrix (Bi) of rank i, and the binary representation of the elements indicates the rank i of the sub-matrix. The sub-matrix (Bi) comprises sub-matrices of dimensions (r-3)x1 and sub-matrices of dimension (r-3)x3. The first three rows of the parity-control matrix comprise sub-matrices (Ai), which comprise sub-matrices of dimension 3x1 and sub-matrices of dimension 3x3; the former sub-matrices contain only digit 0 or digit 1, and the latter sub-matrices are either an identity matrix or its inverse. The sub-matrix (A0) is a sub-matrix of dimension 3x1 which contains only digit 1, and wherein other sub-matrices of dimension 3x1 contain only digit 0. The sub-matrix (Ai) of rank i has a number of columns equal to the number of columns of the sub-matrix (Bi) of the same rank. Two or more rows and/or columns of the parity-control matrix are permitted. The number r of error-detection bits is equal to n+2, where n is such that the number of bits of the word for encoding can be represented by n bits. The method for determining a syndrome representative of the errors eventually occurring in the course of processing is obtained at a step consisting of multiplying a particular matrix (M) of dimension rx(m+r) by a vector having m+r components representative of the rod of m+r bits, where the matrix comprises for m first columns a block of dimension rxm corresponding to the parity-control matrix utilized in coding, and for r last columns a block of dimension rxr in the form of a diagonal matrix, which contains digit 1 on the principal diagonal and digit 0 for other elements.

公开(公告)号：FR2823035B1

公开(公告)日：2003-07-11

申请号：FR0104508

申请日：2001-04-03

Applicant: ST MICROELECTRONICS SA

Inventor： MURILLO LAURENT ,  RICODEAU FRANCOIS

IPC: H03M13/19 ,  H03M13/00 ,  G06F11/10

Abstract: A method for determining r error detection bits that can be associated with a word of m bits to be coded, including the step of calculating the product of a vector with m components representative of the word of m bits to be coded and of a parity control matrix of dimension rxm. The parity control matrix is such that each column of matrix includes an odd number of " 1 s" greater than or equal to three. The present invention also relates to a method for determining a syndrome.