Technique to construct 32/33 and other RLL codes
US6456208B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 30, 2000 |
| Grant date | Sep 24, 2002 |
| Priority date | — |
| Expiry date | Sep 13, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M5/145
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
In this invention a thirty three bit word is encoded from a thirty two bit word to conform to RLL coding constraints. A parity bit is added to the coded word after coding is complete. With the parity bit inserted the code satisfies a minimum Hamming weight of nine and no more than eleven consecutive zeros and no more than eleven consecutive zeros in both the odd and even interleaves. A table of “bad” eight bit sequences is used to compare the odd and even interleaves of the right and left halves of the input word that is being encoded. If a “bad” sequence is found, its position in the table points to a second table containing a four bit replacement code that is inserted into the coded output word. Flag bits in the output coded word are set to indicate the violation of the coding constraints and provide a means by which a decoder can be used to reverse the process and obtain the original input word.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.