Content-addressable memory | EPFL Graph Search

Are you an EPFL student looking for a semester project?

Work with us on data science and visualisation projects, and deploy your project as an app on top of GraphSearch.

Content-addressable memory (CAM) is a special type of computer memory used in certain very-high-speed searching applications. It is also known as associative memory or associative storage and compares input search data against a table of stored data, and returns the address of matching data. CAM is frequently used in networking devices where it speeds up forwarding information base and routing table operations. This kind of associative memory is also used in cache memory. In associative cache memory, both address and content is stored side by side. When the address matches, the corresponding content is fetched from cache memory. Dudley Allen Buck invented the concept of content-addressable memory in 1955. Buck is credited with the idea of recognition unit. Unlike standard computer memory, random-access memory (RAM), in which the user supplies a memory address and the RAM returns the data word stored at that address, a CAM is designed such that the user supplies a data word and the CAM searches its entire memory to see if that data word is stored anywhere in it. If the data word is found, the CAM returns a list of one or more storage addresses where the word was found. Thus, a CAM is the hardware embodiment of what in software terms would be called an associative array. A similar concept can be found in the data word recognition unit, as proposed by Dudley Allen Buck in 1955. A major interface definition for CAMs and other network search engines was specified in an interoperability agreement called the Look-Aside Interface (LA-1 and LA-1B) developed by the Network Processing Forum. Numerous devices conforming to the interoperability agreement have been produced by Integrated Device Technology, Cypress Semiconductor, IBM, Broadcom and others. On December 11, 2007, the OIF published the serial lookaside (SLA) interface agreement. CAM is much faster than RAM in data search applications. There are cost disadvantages to CAM however.

About this result

This page is automatically generated and may contain information that is not correct, complete, up-to-date, or relevant to your search query. The same applies to every other page on this website. Please make sure to verify the information with EPFL's official sources.

Related concepts (7)

Related courses (4)

Related lectures (19)

MICRO-435: Quantum and nanocomputing

The course teaches non von-Neumann architectures. The first part of the course deals with quantum computing, sensing, and communications. The second focuses on field-coupled and conduction-based nanoc

CS-208: Computer architecture I

The course introduces the students to the basic notions of computer architecture and, in particular, to the choices of the Instruction Set Architecture and to the memory hierarchy of modern systems.

CS-307: Introduction to multiprocessor architecture

Multiprocessors are a core component in all types of computing infrastructure, from phones to datacenters. This course will build on the prerequisites of processor design and concurrency to introduce

Cache Memory

Explores cache memory design, hits, misses, and eviction policies in computer systems, emphasizing spatial and temporal locality.

Magnetic Tunnel Junctions: Memory Applications

Explores the evolution and challenges of MRAM technology for memory applications and its potential for future computing paradigms.

Performance: Hardware and Software Optimization

Explores hardware and software optimization for system performance, emphasizing the importance of reducing delay per gate and improving architecture.

A CPU cache is a hardware cache used by the central processing unit (CPU) of a computer to reduce the average cost (time or energy) to access data from the main memory. A cache is a smaller, faster memory, located closer to a processor core, which stores copies of the data from frequently used main memory locations. Most CPUs have a hierarchy of multiple cache levels (L1, L2, often L3, and rarely even L4), with different instruction-specific and data-specific caches at level 1.

Random-access memory (RAM; ræm) is a form of computer memory that can be read and changed in any order, typically used to store working data and machine code. A random-access memory device allows data items to be read or written in almost the same amount of time irrespective of the physical location of data inside the memory, in contrast with other direct-access data storage media (such as hard disks, CD-RWs, DVD-RWs and the older magnetic tapes and drum memory), where the time required to read and write data items varies significantly depending on their physical locations on the recording medium, due to mechanical limitations such as media rotation speeds and arm movement.