Patent · US Expired

Method and apparatus for indicating a duplication of entries in a content addressable storage device

US5220526A · kind A · utility

11Cited by
7References
24Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMar 1, 1991
Grant dateJun 15, 1993
Priority date
Expiry dateMar 1, 2011

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG11C15/00
  • WIPO fieldComputer technology
  • WIPO sectorElectrical engineering

Abstract

An apparatus (10) indicates a duplication of information stored in a content addressable memory (CAM 12) system at the time the information is written to the system. In the CAM system, Match line signals (Match 0-Match (N-1) are asserted when information being written to a predetermined row is identical to information previously stored in the system. However, the Match line signal associated with the predetermined row is disabled by a predetermined transistor (14, 16, 18, 20) when the row is written. Because information is simultaneously presented in parallel to other rows in the CAM system, a Match line signal is asserted if the information currently written to the predetermined row is identical to information previously written to another row in the CAM system. Any asserted Match line signal which was not disabled indicates to the user of the CAM system that two or more entries are identical in the CAM array.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.