Vocabulary:

1) Microprocessor - a realization of the central processing part of a computer on one or more LSI¹⁰ circuits. Characteristics of a microprocessor include small size and low cost.

2) Central processing unit (CPU)- центральный процессор, ЦП

3) Chip - a small piece of silicon on which an integrated circuit is fabricated. More commonly used to describe a complete encapsulated device.

4) Data - a collection of numeric, alphabetic or special characters denoting facts and information.

5) Microcomputer - a class of computers having all the major central processor functions contained on a single printed circuit board or single integrated circuit. A microcomputer contains a microprocessor plus additional circuitry needed to complete the system such as memory, input and output ports, and a clock generator.

6) Floppy disk - a low cost magnetic disk constructed of coated plastic.

7) Magnetic tape - a tape with a magnetic surface on which data can be stored by selective magnetization of portions of the surface.

8) Cassette - a container holding magnetic tape for insertion into tape transport equipment.

9) Memory - a general term which refers to any storage media for data. Basic memory functional types include read/write and read-only.

10) Large-scale integration (LSI)-большая интегральная схема, БИС

Text 3.5 What is a Microprocessor?

Pre-reading task:

1. Read the second part of the text ‘What is a Microprocessor’?

2. Study the definition of terms given below the text.

3. Discuss the following questions in group:

4. Find in the text the definition of a microprocessor. What kind of new information has been added to its content?

5. What is the history of the invention of this logic device?

6. What is the function of the microprocessor?

7. What does a typical microprocessor consist of?

8. What is the feature of bit-sliced chips made by the bipolar technology?

9. How are modern microprocessors differentiated?

Part II

A microprocessor is the central arithmetic and logic unit of a computer, together with its associated circuitry, scaled down so that it fits on a single silicon chip (sometimes several chips) holding tens of thousands of transistors, resistors and similar circuit elements. It is a member of the family of large-scale integrated circuits that reflect the present state of evolution of a miniaturization process that began with the development of the transistor in the late 1940's. A typical microprocessor chip measures half a centimeter on a side. By adding anywhere from 10 to 80 chips to provide timing, program memory, random-access memory¹, interfaces for input and output signals and other ancillary functions, one can assemble a complete computer system on a board whose area does not exceed the size of this page. Such an assembly is a microcomputer, in which the microprocessor serves as the master component. The number of applications for microprocessors is proliferating daily in industry, in banking, in power generation and distribution, in telecommunications and in scores of consumer products, ranging from automobiles to electronic games.

As in the central processing unit, or CPU, of a larger computer, the task of the microprocessor is to receive data in the form of strings of binary digits (O's and 1's), to store the data for later processing, to perform arithmetic and logic operations on the data in accordance with previously stored instructions and to deliver the results to the user through an output mechanism such as an electric typewriter, a cathode-ray-tube² display or a two-dimensional plotter. A typical microprocessor would consist of the following units: a decode and control unit³ (to interpret instructions from the stored program), the arithmetic and logic unit⁵, or ALL) (to perform arithmetic and logic operations), registers (to serve as an easily accessible memory for data frequently manipulated), an accumulator⁵ (a special register closely associated with the ALL)), address⁶ buffers (to supply the control memory with the address from which to fetch⁷ the next instruction) and input-output buffers (to read instructions or data into the microprocessor or to send them out).

Present microprocessors vary in their detailed architecture depending on their manufacture and in some cases on the particular semiconductor technology adopted. One of the major distinctions is whether all the elements of the microprocessor are divided among several identical modular chips that can be linked in parallel, the total number of chips depending on the length of the "word" the user wants to process: four bits (binary digits), eight bits, 16 bits or more. Such a multichip arrangement is known as a bit-sliced organization. A feature of bit-sliced chips made by the bipolar technology is that they are "microprogrammable": they allow the user to create specific sets of instructions, a definite advantage for many applications.