Computer users very often confuse such two concepts as the system unit and the processor, calling the first - the second. This is fundamentally wrong. The processor itself is a device designed to control the operation of a computer by a predetermined sequence of commands called a program, and to perform information processing operations.
In addition, there are other devices with a similar name. For example, a word processor is designed to create documents and format them. This type of program includes Microsoft Word.
What it is?
And the device itself, which is the brain of the computer, is also called a microprocessor. What is the processor in the computer for? This is such an integrated circuit that controls the operation of a personal computer. Such a scheme is created on one or several crystals made of a semiconductor using a very complex technology related to the field of microelectronics.
Everything that a computer with information can do is determined by the command system of the processor itself. They are included in the instructions for managing the computer. One single command is one operation performed by a computer. For example, performing arithmetic operations, logical operations, determining a sequence of commands to execute, transferring information from the memory of one device to the memory of another.
This is the short answer to the question of what the processor is intended for.
Device
Since the processor is a device designed to process data, it consists of the following elements:
- arithmetic-logical device;
- control device;
- memory registers.
The control device, as its name implies, in a given program controls all the nodes of the computer. It extracts each subsequent command from the register, learns from it which operation needs to be performed, and in what sequence. This is a kind of conductor, managing the whole orchestra. And the program serves as the musical composition.
Components
Arithmetic logic device is a tool for calculations, which, following programs, performs operations related to arithmetic and logic.
Registers are the internal memory of the central processor. One register can be compared with a draft, with which the device performs calculations and stores their results. Each of the registers has its own purpose.
Suppose a processor has to add up some two numbers. To perform this operation, first of all, he needs to take the first term from memory, then the second, add up these two values, and transfer the amount again to the computer’s RAM.
It is clear that both terms and the result must be stored somewhere by the processor. For this purpose, a cell is designed that goes directly into the processor itself, called a battery or adder. Since the processor is designed for data and its processing, it must understand from which memory cell the next command should be taken. This he learns from his other inner cell, which is called a counter. The command, which is extracted from the RAM, is located in another cell - the command register. From it, the result of the executed command can already be transferred to RAM.
Types of Registers
Registers come in several forms. They differ from each other in the type of operations that they perform. The most important registers have their own names:
- A command counter is a register containing the address of the next command to be executed. It serves to automatically select a program from a set of related memory cells.
- Adder - takes part in all operations.
- Register of commands. It stores the command for the period of time that is needed to execute.
Data bus
The computer processor is designed to work with information. All his devices are constantly exchanging it with each other. And they do it with the help of an element called the internal data bus. There are other parts to modern central processing units, but the set of devices described above is a necessary minimum.
Machine cycle and its scheme
This process usually consists of the following steps:
- A command is selected from the cell whose address is stored in the counter register. Its contents are increased by the length of this command.
- Then it is sent to the control device, falling into its command register.
- The address field belonging to the command is decrypted by the control device.
- The latter gives a signal, and the data is read from the RAM, getting into the arithmetic-logical device.
- The control unit decrypts the code of the operation to be performed and a signal is sent to the arithmetic-logic device to perform this action on the data, which in this case is called operands.
- The result of the operation can be stored in the central processor itself or transferred to the memory, in the case when there is an address at which the result should be.
- All of the above steps are performed until a stop signal is given.
Characteristics
So, for what the processor is intended, it is clear: to execute commands from a given program. To do this, he has the following characteristics:
- Clock frequency. The central processor is closely connected with a clock frequency generator , which produces pulses. They synchronize among themselves the work of all elements of the computer. This characteristic is equal to the number of measures in one second. One cycle is a period of time between the first pulse and the second. The clock frequency in megahertz is measured.
- Bit depth. This is the maximum value that is responsible for the number of bits of the binary code generated and transmitted by the processor at the same time. This characteristic is determined by the length of its registers.
- Address space It refers to the range of addresses that the processor accesses using the address code.
Thanks to the above, you can clearly determine what the processor is intended for. This is the brain of the computer, without which it is completely unsuitable for anything. Unless to decorate the interior.