The Central processing unit reference article from the English Wikipedia on 24-Jul-2004
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Central processing unit

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The central processing unit (CPU) is the part of a computer that interprets and carries out the instructions contained in the software. In most CPUs, this task is divided between a control unit that directs program flow and one or more execution units that perform operations on data. Almost always, a collection of registers is included to hold operands and intermediate results.

The term CPU is often used vaguely to include other centrally important parts of a computer such as caches and input/output controllers, especially in computers with modern microprocessor chips that include several of these functions in one physical integrated circuit.

A CPUEnlarge


Manufacturers and retailers of desktop computers often erroneously describe the system unit (computer case and its contents) as the CPU; rather, the CPU, as a functional unit, is that part of the computer which actually executes the instructions (add, subtract, shift, fetch, etc.).

A family of CPU designs is often referred to as a CPU architecture.

Table of contents
1 Notable CPU architectures include:
2 Emerging new CPU architectures include:
3 Historically important CPUs have been:
4 See also

Notable CPU architectures include:

Emerging new CPU architectures include:

Historically important CPUs have been:

The above processor architectures could also be characterized by their CPU design like register size. Today most desktop computers have 32-bit processors; 64-bit processors are being phased in. Smaller devices like mobile phones, PDAss, or portable video game devices may have 16 or 8-bit processors.

See also