Abstract: A general rate N/(N+1) (0, G), code construction, e.g., for a magnetic recording system, allows for encoding or decoding of a dataword having N elements, N preferably being an integer multiple of eight. The dataword is divided into N/8 bytes of binary data that are encoded as a run-length limited (RLL) codeword in accordance with the general rate N/(N+1) (0, G) code construction. The general rate N/(N+1) (0, G) code construction is characterized by the constraints (d=0, G=(N/4)+1, l=N/8, r=N/8). the N/(N+1) (0 (N/4)+1, N/8, N/8) RLL codeword is constructed from the dataword in accordance with 1) pivot bits identifying code violations related to the constraints, 2) correction bits set to correct code violations, and 3) preserved elements having values not included in the code violations.

Abstract: A system and method employing a rate 24/25 (0,9) code constructed in accordance with a data byte interleaved with a rate 16/17 (0,5) codeword formed from two data bytes limits the number of consecutive zeros seen by a channel to nine. The 16/17 (0,5) codeword is formed from the two data bytes in accordance with a set of pivot bits and a set of corrections for predefined code violations. The additional data byte is interleaved into the 16/17 (0,5) codeword by splitting the byte into a pair of portions and inserting the portions into the 16/17 (0,5) codeword at locations adjacent to predefined ones of the pivot bits. The rate 24/25 (0,9) code is suitable for magnetic or similar recording media and may be employed in partial response maximum likelihood read channels. A feature of the constructed code is a high transition density which allows for more frequent timing and gain control updates, which results in lower required channel input signal to noise ratio for a given channel performance.

Abstract: A system and method employing a rate 16/17 (0,5) code constructed in accordance with a set of pivot bits and a set of corrections for predefined code violations limits the number of consecutive zeros seen by a channel to five. The rate 16/17 (0,5) code is suitable for magnetic or similar recording media and may be employed in partial response maximum likelihood read channels. A feature of the constructed code is a high transition density which allows for more frequent timing and gain control updates, which results in lower required channel input signal to noise ratio for a given channel performance. Each constructed codeword is block encodable and block decodable, and the code construction allows for efficient circuit implementation in both an encoder and a decoder.