Today, the homes of the vast majority of residents of developed countries have several computers, as well as tablets and other mobile devices. The “heart” of any of them is the processor (CPU or CPU). It has a complex structure. To understand how a PC works, you should find out what is included in the processor.
Purpose and functions
Before you study the devices that make up the processor, you should find out what it is for. So, the processor is the central device of the PC. Its purpose is:
- manage the operation of the computer, following a given program;
- perform information processing operations.
Devices that are part of the processor
At the moment, the CPU is a special integrated circuit.
The devices that make up the processor are:
- register;
- cache memory;
- data and address buses;
- ALU (arithmetic logic device);
- mathematical coprocessor.
Register
This is a block of memory cells that form ultrafast RAM memory inside the CPU. It is used by him and is not available to programmers. The amount of memory is only a few hundred bytes.
CPU registers are divided into 2 types: general purpose and special.
Registers of the 1st type are used when operations of logical and arithmetic type or operations of such additional sets of instructions as SSE, MMX, etc. are performed.
The registers of the second type contain the system data required for the processor. These include control registers, system addresses, debugging, etc. Access to them is strictly regulated.
In addition, such a device includes a command counter containing the address of the command that the CPU will begin to execute at the next clock cycle.
Cache memory
The devices that make up the processor are quite diverse. These include cache. It is a superoperative memory. The purpose of its use is to speed up the PC. To do this, when the CPU accesses memory, it first checks whether the requested data is stored in the cache. For this purpose, the address of the received request is compared with the values of all cache tags where this data can be stored. A cache line match with a tag is called a hit (cache hit). In the opposite case, a cache miss is recorded. Cache hit allows the processor to immediately read or write data in a line with a matching tag. A measure of cache efficiency for a selected algorithm (program) is the ratio of the number of successful hits to the cache to the total number of processor requests for memory, called the hit rating.
Alu
Although some devices that are part of the processor have their own memory, ALU is a special combinational circuit without elements of its own memory. Its purpose is to implement the most important operations of the data processing process:
- accepts 2 operands to 2 inputs (contents of 2 registers, etc.);
- forms and outputs the result of the operation.
It consists in performing a set of simple arithmetic operations (AO), divided into 3 main categories: logical, arithmetic, and bit operations. AOs are data processing procedures (subtraction, addition, multiplication or division), the arguments and the result of which are numbers. They differ from logical operations. They are understood as procedures that carry out the construction of complex statements (AND, NOT, OR).
The arithmetic-logical device consists of registers, a control element and an adder with logic circuits. It operates in accordance with the codes of operations performed on variables that are placed in registers.
Data and Address Buses
These devices, which are part of the processor, are a set of conductors. The first of them is designed to transmit the address of the memory cell to which data is sent. For each of them 1 bit is transmitted. It corresponds to 1 digit in the address. An increase in the number of conductors used to form the address makes it possible to mark a larger number of cells. The bus width determines the maximum amount of memory that can be addressed by the processor.
If we compare the data bus with the freeway and consider its width with the number of lanes, then the address bus is associated with the numbering of streets or houses. The number of its lines is equal to the number of digits (signs) in the house number. Thus, if on a particular street house numbers consist of more than 2 decimal digits, then the number of houses located on it cannot exceed 100 (i.e., 102). With 3-digit numbers, the number of possible addresses increases to 103.
The address and data buses are independent, and the chip designers themselves choose their bit capacity at their discretion. At the same time, the more bits there are in the data bus, the more there are in the address bus. Their capacity is an indicator of the capabilities of a particular processor. In particular, in the data bus it determines the ability of the processor in the matter of information exchange, and the width of the address bus indicates the amount of memory with which it has the ability to work.
Math coprocessor
Continuing to consider what is included in the computer processor, a few words can be said about this device. It is designed to expand the capabilities of the CPU and ensure its functionality through the module of the so-called floating point operations, for processors that do not have an integrated module.
The mathematical coprocessor is not one of the essential elements of a PC, and you can refuse it. Previously, many manufacturers did just that for reasons of economy.
However, when solving problems requiring a lot of mathematical calculations (in scientific or engineering calculations), I had to solve the problem of improving PC performance.
If earlier the mathematical coprocessor module was installed on the motherboard as a separate chip, then in modern personal computers the use of this device in this format is not required, since it was originally built into the central processor.
Other PC devices
A personal computer is a complex and well-functioning system.
It is impossible to list all possible devices that are part of the computer in a nutshell.
In addition to the processor, the PC also includes:
- a motherboard with a CPU connector;
- hard disk drives and flexible magnetic disks ;
- Power Supply;
- random access memory;
- CD and DVD drives
- connectors (ports) for additional devices, etc.
In addition, various peripheral devices are used, such as:
- computer mouse;
- keyboard;
- microphone;
- speakers, etc.
Now you know that all the possible devices that make up a computer are parts of a complex processor-controlled system. It is difficult to overestimate its role, since PC operation depends on its normal functioning. At the moment, experts predict that in the coming decades the material part of the processors will undergo significant changes. This is due to the fact that the technological process is outdated, quantum, biological, etc. computers will replace the usual PCs.