Hash Cam having a reduced size memory array and its application
US6438674B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Dec 21, 1999 |
| Grant date | Aug 20, 2002 |
| Priority date | — |
| Expiry date | Dec 21, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C15/00
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A hash CAM is provided with a hashing unit and a memory array. The hashing unit is designed to generate an n-bit index in response to an m-bit input, where n and m are positive integers, and n is smaller than m. The memory array is designed to store a number of truncated comparands of size r (in units of bits), and to output a selected one of the stored truncated comparands in accordance with the n-bit index, for comparison with a subset of r selected bits of the m-bit input, where r is also a positive integer, and m−r is less than or equal to n. In each of a number of applications, a look-up engine is provided with the hash CAM. In one particular application, a forwarding section of a networking device is provided with such look-up engine.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.