Code conversion method

Abstract

A code conversion method that may be used for uniquely converting n-bit codes inclusive of those capable of being converted into first and second m-bit data, where n>m. With the present method, a conversion table may be reduced for reducing the size of the conversion circuit. At a step S1, a status bit specifying whether or not a n-bit code next following the n-bit code being converted is a first pre-set codestring. At a step S2, the n-bit codes are split into a first code made up of upper k bits, where 0<k<n, and a second code made up of lower n-k bits. At a step S3, the result of conversion is obtained from a conversion table outputting m-bit data associated with n-bit codes represented by the combination of the first and second codes, with account being taken of the status bit. Second m-bit data are allocated to the combinations of the first and second codes constituting the n-bit code capable of being converted into two m-bit data are allocated to those addresses of the conversion table which are associated with the combinations of the first and second codes excluded by the minimum run-length limitations for the n-bit codes.