Browse Prior Art Database

Contents Addressable Memory

IP.com Disclosure Number: IPCOM000057086D
Original Publication Date: 1988-Mar-01
Included in the Prior Art Database: 2005-Feb-14

Publishing Venue

IBM

Related People

Authors:
Dahl, SS Hoover, RD Morse, RD Salamian, MA [+details]

Abstract

A Contents Addressable Memory (CAM) is a device which decreases the average access time for a memory access and in general, it is a small copy (16 bytes) of Main Store of the processor or computer. When given a real memory address, the CAM searches its Address Keys to determine if it contains that Main Store location. If it does (hit), it will gate out those bytes for the Main Store Processor (MSP) to operate on. If the CAM does not contain that Main Store location (miss), it will indicate this and force the MSP to initiate a Main Store access. On each Main Store access, four bytes will be brought out, with the MSP using only two of the four bytes. All four bytes will be put in the CAM, as well as the real address for future use. The data flow diagram for the CAM of MSP is shown in the figure.