Central processing unit

"CPU" redirects here. For other uses, see CPU (disambiguation).
Inside a central processing unit: The integrated circuit of Intel's Xeon 3060, first manufactured in 2006

A central processing unit (CPU), also called a central processor, main processor, or just processor, is the most important processor in a given computer.[1][2] Its electronic circuitry executes instructions of a computer program, such as arithmetic, logic, controlling, and input/output (I/O) operations.[3][4][5] This role contrasts with that of external components, such as main memory and I/O circuitry,[6] and specialized coprocessors such as graphics processing units (GPUs).

The form, design, and implementation of CPUs have changed over time, but their fundamental operation remains almost unchanged.[7] Principal components of a CPU include the arithmetic–logic unit (ALU) that performs arithmetic and logic operations, processor registers that supply operands to the ALU and store the results of ALU operations, and a control unit that orchestrates the fetching (from memory), decoding and execution (of instructions) by directing the coordinated operations of the ALU, registers, and other components. Modern CPUs devote a lot of semiconductor area to caches and instruction-level parallelism to increase performance and to CPU modes to support operating systems and virtualization.

Most modern CPUs are implemented on integrated circuit (IC) microprocessors, with one or more CPUs on a single IC chip. Microprocessor chips with multiple CPUs are called multi-core processors.[8] The individual physical CPUs, called processor cores, can also be multithreaded to support CPU-level multithreading.[9]

An IC that contains a CPU may also contain memory, peripheral interfaces, and other components of a computer;[10] such integrated devices are variously called microcontrollers or systems on a chip (SoC).

  1. ^ Team, YCT Expert. Engineering Drawing & Basic Science. Youth Competition Times. p. 425.
  2. ^ Nagpal, D. P. (2008). Computer Fundamentals. S. Chand Publishing. p. 33. ISBN 978-81-219-2388-0.
  3. ^ "What is processor (CPU)? A definition from WhatIs.com". WhatIs. Retrieved 2024-03-15.
  4. ^ Chesalov, Alexander (2023-04-12). The fourth industrial revolution glossarium: over 1500 of the hottest terms you will use to create the future. Litres. ISBN 978-5-04-541163-9.
  5. ^ Jagare, Ulrika (2022-04-19). Operating AI: Bridging the Gap Between Technology and Business. John Wiley & Sons. ISBN 978-1-119-83321-5.
  6. ^ Kuck, David (1978). Computers and Computations, Vol 1. John Wiley & Sons, Inc. p. 12. ISBN 978-0471027164.
  7. ^ Prabhat, Team (2023-04-13). Ultimate Guide to SSC CGL Combined Graduate Level Tier-I & Tier II Prelims & Mains (with Latest Solved Question Papers) Guide Book English: Bestseller Book by Team Prabhat: Ultimate Guide to SSC CGL Combined Graduate Level Tier-I & Tier II Prelims & Mains (with Latest Solved Question Papers) Guide Book English. Prabhat Prakashan. p. 95. ISBN 978-93-5488-527-3.
  8. ^ "What is a multicore processor and how does it work?". Data Center. Retrieved 2024-03-15.
  9. ^ Cite error: The named reference intel-pcm was invoked but never defined (see the help page).
  10. ^ Herres, David (2020-10-06). Oscilloscopes: A Manual for Students, Engineers, and Scientists. Springer Nature. p. 130. ISBN 978-3-030-53885-9.