Content Addressable Parallel Processor
Encyclopedia
A Content Addressable Parallel Processor (CAPP) is a type of parallel processor
which uses content-addressing memory
(CAM) principles. CAPPs are intended for bulk computation. The syntactic structure of their computing algorithm
are simple, whereas the number of concurrent processes may be very large, only limited by the number of locations in the CAM. The best-known CAPP may be STARAN
, completed in 1972; several similar systems were later built in other countries.
A CAPP is distinctly different from an Von Neumann architecture
or classical computer that stores data in cells addressed individually by numeric address. The CAPP executes a stream of instructions that address memory based on the content (stored values) of the memory cells. As a parallel processor, it acts on all of the cells containing that content at once. The content of all matching cells can be changed simultaneously.
A typical CAPP might consist of an array of content-addressable memory of fixed word length, an sequential instruction store, and a general purpose computer of the Von Neumann architecture that is used to interface peripherals.
Parallel computing
Parallel computing is a form of computation in which many calculations are carried out simultaneously, operating on the principle that large problems can often be divided into smaller ones, which are then solved concurrently . There are several different forms of parallel computing: bit-level,...
which uses content-addressing memory
Content-addressable memory
Content-addressable memory is a special type of computer memory used in certain very high speed searching applications. It is also known as associative memory, associative storage, or associative array, although the last term is more often used for a programming data structure...
(CAM) principles. CAPPs are intended for bulk computation. The syntactic structure of their computing algorithm
Algorithm
In mathematics and computer science, an algorithm is an effective method expressed as a finite list of well-defined instructions for calculating a function. Algorithms are used for calculation, data processing, and automated reasoning...
are simple, whereas the number of concurrent processes may be very large, only limited by the number of locations in the CAM. The best-known CAPP may be STARAN
STARAN
STARAN might be the first commercially available computer designed around an associative memory. The STARAN computer was designed and built by Goodyear Aerospace Corporation. It is a Content Addressable Parallel Processor, a type of parallel processor which uses content addressable memory...
, completed in 1972; several similar systems were later built in other countries.
A CAPP is distinctly different from an Von Neumann architecture
Von Neumann architecture
The term Von Neumann architecture, aka the Von Neumann model, derives from a computer architecture proposal by the mathematician and early computer scientist John von Neumann and others, dated June 30, 1945, entitled First Draft of a Report on the EDVAC...
or classical computer that stores data in cells addressed individually by numeric address. The CAPP executes a stream of instructions that address memory based on the content (stored values) of the memory cells. As a parallel processor, it acts on all of the cells containing that content at once. The content of all matching cells can be changed simultaneously.
A typical CAPP might consist of an array of content-addressable memory of fixed word length, an sequential instruction store, and a general purpose computer of the Von Neumann architecture that is used to interface peripherals.