Patent ID: 7478311
Filing Date: 2009-01-13
Classification: G11B,H03M

Abstract:
1. An error detection apparatus having a syndrome operator for performing syndrome operation to target code strings, each target code string comprising plural sectors and each sector comprising matrix data, and performing an error correction processing by an error correction circuit to the target code strings, and simultaneously, performing error detection to the target code strings in sector units, said apparatus comprising: an error detection code operation circuit for calculating error detection codes in the target code strings; an error detection code skip operation circuit for, when the target code strings are inputted in a discontinuous arrangement, performing a skip operation for correcting the inter-data continuity by skipping the data so as to make the arrangement of the code strings continuous; a first error detection control circuit for controlling a first error detection code operation performed by the error detection code operation circuit and the error detection code skip operation circuit, which is carried out simultaneously with the syndrome operation; a second error detection control circuit for controlling, after the error correction processing, a second error detection code operation only for data indicated by error data position on the basis of the error data positions and error data numeral values that are obtained by the error correction processing, and controlling an updation processing for updating the operation result of the first error detection code operation on the basis of the operation result of the second error detection code operation; and a memory for holding the operation results by the error detection code operation circuit, and the error detection code skip operation circuit; wherein said error detection code skip operation circuit receives error detection codes of the target code strings which have been inputted by the last time, and performs a skip operation for skipping a predetermined number of bytes in non-final rows in the sector among the target code strings, and performs an individual skip operation for skipping a number of bytes according to column positions where data exist, in a final row in the sector; and said individual skip operation is performed by utilizing, plural times, the operation result of the skip operation which are executed in a specific column position among the column positions where data exist.