Patent · US Expired

Method and apparatus for cascading content addressable memory devices

US6148364A · kind A · utility

140Cited by
55References
31Claims
0Family size

Assignee

Inventors

Key dates

Filing dateDec 30, 1997
Grant dateNov 14, 2000
Priority date
Expiry dateDec 30, 2017

Classification

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

Abstract

A method and apparatus for cascading content addressable memory (CAM) devices is disclosed. The method and apparatus may be particularly useful when depth cascading CAM devices that operate in a flow-through mode. In the flow-through mode, a compare instruction may be simultaneously provided to each CAM device in the cascade, and the match address, data stored at the matched location, or other status information may then be output to a common output data bus by the highest priority matching CAM device in the same cycle that the instruction is provided to the CAM devices. Each CAM device may have a cascade input and a cascade output to perform the cascade function. The cascade output of a higher priority CAM device may be connected to the cascade input of the next lower priority CAM device. The higher priority CAM device may assert a cascade signal on its cascade output at a predetermined time after receiving an input signal (e.g., a clock signal). Asserting the cascade signal may indicate that the higher priority CAM device has completed the compare instruction. When the lower priority CAM device detects that the cascade signal has been asserted on its cascade input, the lower prio…

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