CD-ROM subcode R-W channel de-interleaving and de-scrambling method and apparatus
US5502696A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 23, 1994 |
| Grant date | Mar 26, 1996 |
| Priority date | — |
| Expiry date | Sep 23, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2220/2545
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A subcode R-W channel data de-interleaving and de-scrambling method and apparatus includes the ability to de-interleave and de-scramble the encoded subchannel data without the necessity of storage elements, by dynamically calculating the final location of each byte of data within a packet as it is read from the CD-Rom. A pack counter monitors the pack number of the current byte of data. An index counter monitors the location of the current data within a pack. A subtractor uses the values from the pack counter and the index counter to obtain an input value, a first portion of which is supplied to a first offset generator. A second portion of the subtractor output is used to select a base address. The first offset generator determines the pack number of the current byte of data after the de-interleave process. A second offset generator receives a value from the index counter and generates a corresponding value. The results from the first offset generator and the second offset generator are both input into a first adder. The output of the first adder is added to the selected base address by a second adder in order to calculate the final address. The final address is transmitted with t…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.