Microprocessor – Concept, history and characteristics

We explain what a microprocessor is, the history and characteristics of this integrated circuit. Also, what it is for and its functions.

A microprocessor can operate with one or more CPUs.

What is a microprocessor?

It’s called a microprocessor or just a processor to the central integrated circuit of a computer system, where the logical and arithmetic operations (calculations) are carried out to allow the execution of the programs, from the Operating System to the application Software.

A microprocessor can operate with one or more CPUs (Central Processing Units), each made up of registers, a control unit, an arithmetic-logical unit and a floating point calculation unit (or mathematical coprocessor).

Likewise, it has generally been connected by means of a socket to the motherboard or motherboard, together with a heat sink system made up of certain thermal dissipation materials and a fan cooler (internal fan).

While the same microprocessor can have one or more physical or logical cores, in which all the calculation work is carried out, the same computer system can have several processors working in parallel.

The performance of these processors is not easy to measure, but the clock frequency (measured in Hertz) is often used to distinguish between the power of one and the other.

History of the microprocessor

Microprocessors emerged as a product of the technological evolution of two specific branches: computing and semiconductors. Both had their beginnings in the middle of the 20th century, in the context of World War II, with the invention of the transistor, with which vacuum tubes were replaced.

Since then, silicon was used to generate simple electronic circuits, leading later (the beginning of the 1960s) to the creation of the first digital circuits: Transistor-Resistor Logic (RTL), Transistor Diode Logic (DTL) , Transistor-Transistor Logic (TTL) and Emitter Complemented Logic (ECL).

The next step towards microprocessors would be the invention of integrated circuits (SSI and MSI), thus allowing the beginning of the aggregation and miniaturization of components. The first calculators to use this technology, however, required between 75 and 100 integrated circuits, which was impractical. And so the next step in downsizing the computational architecture was the development of the first microprocessors.

The first processor was the Intel 4004 manufactured in 1971. It contained 2300 transistors and with its only 4 bits of capacity it could carry out 60,000 logic operations per second, at a clock frequency of 700 Hz. From then on, the technological race invested in the development of better and more powerful microchips: 8 bits , 16 bits, 32 bits and 64 bits, currently reaching frequencies above 3 GHz.

Microprocessor Features

Caching prevents RAM from being used unnecessarily.

The microprocessors resemble a small miniature digital computer, so it presents its own architecture and performs operations under a control program. This architecture is composed of:

  • Encapsulated. A ceramic coating that covers the silicon and protects it from the elements (such as oxygen in the air).
  • Cache. A type of ultra-fast memory available for the processor, so that it uses RAM only when necessary, since data in use is saved in the various levels of the cache for immediate recovery.
  • Math coprocessor. Called the floating point unit, it is the portion of the processor that handles logical and formal operations.
  • Records. A short working memory in the processor, designed to keep track of its own operation and conditions.
  • Ports. The conduits that allow the processor to communicate information with the rest of the system components.

What is a microprocessor for?

Microprocessors are the “brain” of the computer: its logical center of arithmetic and logical operations, where all the system programs will run, both those of the Operating System, as well as the applications executed by the user. The system binary logics and memory accesses are also given there. That is to say: the processor is the informational engine of the computer.

Microprocessor function

The fetch is the sending of the specific instruction to the decoder.

A microprocessor operates on the basis of a series of elementary instructions that are pre-programmed and stored in the form of binary code. These instructions will be organized into the main memory, and are given according to several phases, which are:

  • Prefetch. Or pre-reading of the instruction from the main memory of the system.
  • Fetch. Sending the specific instruction to the decoder.
  • Decoding. Translation of the instruction into a series of operations to be carried out, and reading of the necessary operands to do so.
  • Execution. Completion of training by the components of the system.
  • Writing. Recording of the results back in main memory, or in the registers.

These phases are carried out in several CPU cycles, and their duration depends on the frequency at which the microprocessor works.