| 摘要 |
A method for correcting errors in up to three tracks or channels in a multi-track data system is provided. Message data is formed into a codeword by adding three check bytes thereto which are dependent on each other and are generated from the information bytes. After the data has undergone some form of transposition, at which time it is desirable to check for errors and correct any errors within the capability of the code, the transposed data is decoded so as to generate three syndromes. At the time of data transposition, error pointers may be provided. When the provided pointers indicate that either two or three tracks contain errors, error patterns are generated and added to the information already within the tracks in error, to correct the errors. If only one pointer is provided, a check is made to see whether or not another track is in error even though a pointer was not provided, and, if an additional track is in error, its pointer is generated. Thereafter these two tracks are corrected. Similarly, if no pointer is provided, a check is made to determine whether or not there was at least one track in error. If so, the pointer is generated and the error is corrected. An uncorrectable error indication is provided when errors are encountered that lie outside of the correction capability of the code. |
