Microprocessor

A microprocessor is a computer processor for which the data processing logic and control is included on a single integrated circuit (IC), or a small number of ICs. The microprocessor contains the arithmetic, logic, and control circuitry required to perform the functions of a computer's central processing unit (CPU). The IC is capable of interpreting and executing program instructions and performing arithmetic operations.^[1] The microprocessor is a multipurpose, clock-driven, register-based, digital integrated circuit that accepts binary data as input, processes it according to instructions stored in its memory, and provides results (also in binary form) as output. Microprocessors contain both combinational logic and sequential digital logic, and operate on numbers and symbols represented in the binary number system.

The integration of a whole CPU onto a single or a few integrated circuits using Very-Large-Scale Integration (VLSI) greatly reduced the cost of processing power. Integrated circuit processors are produced in large numbers by highly automated metal–oxide–semiconductor (MOS) fabrication processes, resulting in a relatively low unit price. Single-chip processors increase reliability because there are fewer electrical connections that can fail. As microprocessor designs improve, the cost of manufacturing a chip (with smaller components built on a semiconductor chip the same size) generally stays the same according to Rock's law.

Before microprocessors, small computers had been built using racks of circuit boards with many medium- and small-scale integrated circuits, typically of TTL type. Microprocessors combined this into one or a few large-scale ICs. While there is disagreement over who deserves credit for the invention of the microprocessor, the first commercially available microprocessor was the Intel 4004, designed by Federico Faggin and introduced in 1971.^[2]

Continued increases in microprocessor capacity have since rendered other forms of computers almost completely obsolete (see history of computing hardware), with one or more microprocessors used in everything from the smallest embedded systems and handheld devices to the largest mainframes and supercomputers.

A microprocessor is distinct from a microcontroller including a system on a chip.^[3]^[4] A microprocessor is related but distinct from a digital signal processor, a specialized microprocessor chip, with its architecture optimized for the operational needs of digital signal processing.^[5]^{: 104–107}^[6]

^ Orion, Veritas (23 August 2024). "What distinguishes a microprocessor from a microcontroller?". Ampheo Electronics. Orion Veritas.
^ "The Surprising Story of the First Microprocessors". 30 August 2016. Archived from the original on 4 October 2022. Retrieved 4 October 2022.
^ Warnes, Lionel (2003). "Microprocessors and microcontrollers". Electronic and Electrical Engineering. London: Macmillan Education UK. pp. 443–477. doi:10.1007/978-0-230-21633-4_23. ISBN 978-0-333-99040-7. microprocessor is not a stand-alone computer, since it lacks memory and input/output control. These are the missing parts that the microcontroller supplies, making it more nearly a complete computer on a chip.
^ Morris, Noel M. (1985). Microelectronic and Microprocessor-based Systems. London: Macmillan Education UK. p. 16. doi:10.1007/978-1-349-06978-1. ISBN 978-0-333-36190-0. A microprocessor itself is incapable of performing calculations and requires a support system in order to do so. The CPU support system includes a storage system in which not only the operating instructions but also the data (operands) are stored.
^ Dyer, Stephen A.; Harms, Brian K. (13 August 1993). "Digital Signal Processing". In Yovits, Marshall C. (ed.). Advances in Computers. Vol. 37. Academic Press. pp. 59–118. doi:10.1016/S0065-2458(08)60403-9. ISBN 978-0120121373. ISSN 0065-2458. LCCN 59015761. OCLC 858439915. OL 10070096M.
^ Liptak, B. G. (2006). Process Control and Optimization. Instrument Engineers' Handbook. Vol. 2 (4th ed.). CRC Press. pp. 11–12. ISBN 978-0849310812 – via Google Books.

[1] Orion, Veritas (23 August 2024). "What distinguishes a microprocessor from a microcontroller?". Ampheo Electronics. Orion Veritas.

[IEEE-2] "The Surprising Story of the First Microprocessors". 30 August 2016. Archived from the original on 4 October 2022. Retrieved 4 October 2022.

[Warnes_2003_pp._443–477-3] Warnes, Lionel (2003). "Microprocessors and microcontrollers". Electronic and Electrical Engineering. London: Macmillan Education UK. pp. 443–477. doi:10.1007/978-0-230-21633-4_23. ISBN 978-0-333-99040-7. microprocessor is not a stand-alone computer, since it lacks memory and input/output control. These are the missing parts that the microcontroller supplies, making it more nearly a complete computer on a chip.

[Morris_1985_p.-4] Morris, Noel M. (1985). Microelectronic and Microprocessor-based Systems. London: Macmillan Education UK. p. 16. doi:10.1007/978-1-349-06978-1. ISBN 978-0-333-36190-0. A microprocessor itself is incapable of performing calculations and requires a support system in order to do so. The CPU support system includes a storage system in which not only the operating instructions but also the data (operands) are stored.

[5] Dyer, Stephen A.; Harms, Brian K. (13 August 1993). "Digital Signal Processing". In Yovits, Marshall C. (ed.). Advances in Computers. Vol. 37. Academic Press. pp. 59–118. doi:10.1016/S0065-2458(08)60403-9. ISBN 978-0120121373. ISSN 0065-2458. LCCN 59015761. OCLC 858439915. OL 10070096M.

[Liptak-6] Liptak, B. G. (2006). Process Control and Optimization. Instrument Engineers' Handbook. Vol. 2 (4th ed.). CRC Press. pp. 11–12. ISBN 978-0849310812 – via Google Books.

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