Multi-stage lookup for translating between signals of different bit lengths
US6420982B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Dec 18, 2001 |
| Grant date | Jul 16, 2002 |
| Priority date | — |
| Expiry date | Dec 18, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L49/354
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A method and apparatus is provided for translating an L-bit put signal to a W-bit output signal such as a virtual network identification signal to an internal virtual network signal. The translation is performed using a multi-stage lookup. The input signal is portioned into a plurality of subsets of bits. A first index to a first stage is provided by combining a portion of bits and a first delta subset of bits. A second index to a second stage is provided by combining data stored at the first index in the first stage and the a second delta subset of bits. The corresponding output signal is stored at the last index in the last stage. The use of the multi-stage lookup instead of a single-stage lookup reduces the memory required to perform the translation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.