公开(公告)号：JPH11185399A

公开(公告)日：1999-07-09

申请号：JP34643897

申请日：1997-12-16

Applicant: IBM

Inventor： DEMURA MASAYUKI ,  TAMURA TETSUYA ,  SASAKI AKIRA ,  ITAGAKI HIROSHI

IPC: G11B20/12 ,  G11B20/18 ,  H03M13/00 ,  H03M13/15 ,  H03M13/29

Abstract: PROBLEM TO BE SOLVED: To provide a method performing the coding of an ECC(error-correcting code) block efficiently in order to enhance a write performance to a storage device in which an ECC block having liner codes like a Reed-Solomon code is adopted. SOLUTION: At the time of calculating an ECC block F2 having a PO part q2 posterior to an updating by updating the data f1 of the data sector of one parts being in plural data sectors constituting an ECC block F1 having the PO part q1 generated with linear codes like the Reed-Solomon code with data f2 , and exclusive OR f1 +f2 between data f1 to be updated and updated f2 is calculated by operating ECC blocks F1 +F2 being an exclusive OR between source data parts the ECC block F1 prior to the updating and the ECC block F2 posterior to the updating. Exclusive ORs among data sectors which are not updated become zero. Next, when codings are performed as to the ECC blocks F1 +F2 being the exclusive OR, an OP part having the form of an exclusive OR q1 +q2 is obtained by the linear property of the Reed-Solomon code. Then, q2 can be calculated by the exclusive OR between q1 +q2 and q1 .