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What's inside a microcomputer
The nerve centre of a microcomputer is the central processing unit or CPU. This unit is built into a single microprocessor chip - an integrated circuit - which executes program instructions and supervises the computer's overall operation. The unit consists of three main parts:
the control unit, which examines the instructions in the user's program, interprets each instruction and causes the circuits and the rest of the components - disk drives, monitor, etc. - to be activated to execute the functions specified;
the arithmetic logic unit (ALU), which performs mathematical calculations (+, -, etc.) and logical operations (and, or, etc.);
the registers, which are high-speed units of memory used to store and control information. One of these registers is the program counter (PC) which keeps track of the next instruction to be performed in the main memory. Another is the instruction register (IR) which holds the instruction that is currently being executed (see Fig. 1.)
One area where microprocessors differ is in the amount of data - the number of bits – they can work with at a time. There are 8, 16, 32 and 64- bit processors. The computer's internal architecture is evolving so quickly that the new 30 64-bit processors are able to address 4 billion times more information than a 32-bit system (see Fig. 2).
The programs and data which pass through the central processor must be loaded into the 35 main memory (also called the internal memory) in order to be processed. Thus, when the user runs an application, the microprocessor looks for it on secondary storage devices (disks) and transfers a copy of 40 the application into the RAM area. RAM (random access memory) is temporary, i.e. its information is lost when the computer is turned off. However, the ROM section (read only memory) is permanent and contains 45 instructions needed by the processor.
Most of today's computers have internal expansion slots that allow users to install adapters or expansion boards. Popular adapters include high-resolution graphics boards, memory expansion boards, and 50 internal modems.
The power and performance of a computer is partly determined by the speed of its microprocessor. A clock provides pulses at fixed intervals to measure and synchronize 55 circuits and units. The clock speed is measured in MHz (megahertz) and refers to the frequency at which pulses are emitted. For example, a CPU running at 500 MHz (500 million cycles per second) is likely to provide a very fast 60 processing rate and will enable the computer to handle the most demanding applications.
2) Відповіді на питання по тексту:
1) What is the nerve centre of a microcomputer?
2) What is an integrated circuit?
3) What parts does the CPU consist of?
4) What is the function of the control unit?
5) Decode the abbreviation: ALU.
6) What does ALU do?
7) What are the registers used for?
8) What registers are mentioned in the text?
3) Читання студентами другої частини тексту і виконання вправ:
A) Знайти в тексті еквіваленти наступних слів:
1) Одночасно; 2) внутрішня конфігурація (структура); 3) плати розширення пам’яті; 4) вимірювати; 5) лічильник програм; 6) пам’ять; 7) розвиватися, еволюціонувати; 8) додаток, програма; 9) пристрої збереження інформації; 10) вимкнути ком’ютер; 11) частота.
В) Декодування скорочень( закріплення та подальше осмислення прочитаного):
1) CPU; 2) ALU; 3) ROM; 4) RAM; 5) PC (двома способами); 6) RISC; 7) IR; 8) MHz; 9) CAD.
5 Домашнє завдання: повторити слова(нову лексику), перекласти уривок тексту (33-51рядки), узагальнити прочитане( усно).