The CPU, or Central Processing Unit, is the brain of your computer. It handles all the instructions your computer receives, and carries out the necessary calculations to carry out those instructions. In short, Basic functions of CPU, your computer would be nothing more than a glorified paperweight.
When most people think of a computer, they think of the monitor, keyboard, and mouse. But the heart of a computer is actually the Central Processing Unit (CPU).
The CPU is responsible for performing all the calculations required to run your programs and applications. It also controls all communication between your computer’s hardware and software. In other words, the CPU is responsible for everything that happens on your computer!
Contents
The CPU is made up of two main parts: Basic functions of CPU the control unit and the arithmetic/logic unit. The control unit is responsible for fetching instructions from memory and executing them. The arithmetic/logic unit is responsible for performing all the mathematical calculations, as well as logical comparisons.
A Microprocessor
A microprocessor is a computer processor that incorporates the functions of a central processing unit on a single integrated circuit (IC), or at most a few integrated circuits.
The microprocessor is a multipurpose, programmable device that accepts binary data as input, processes it according to instructions stored in its memory, and provides results (also in binary form) as output. Microprocessors contain both combinational logic and sequential digital logic.
Memory or Storage Unit
The control unit (CU) is the brain of the computer. It controls all the other units in the system and tells them what to do.
The arithmetic logic unit (ALU) is responsible for all the calculations that are carried out by the computer. The registers are used to store data and instructions temporarily.
The Control Unit
The control unit (CU) is a component of a computer’s central processing unit (CPU) that directs the operation of the processor. It tells the computer’s memory, arithmetic, logic unit, and input and output devices how to respond to the instructions that have been stored in memory.
The control unit does not carry out these operations itself, but it contains the circuitry that tells the other units what to do.
Arithmetic Logic Unit
An arithmetic logic unit (ALU) is a digital circuit that performs arithmetic and logic operations. The ALU is a fundamental building block of the central processing unit (CPU) of a computer. A single CPU may contain multiple ALUs.
The operations performed by an ALU include addition, subtraction, multiplication, division, and logic operations such as AND, OR, NOT, and XOR.
In addition to functioning as the primary calculator of the CPU, the ALU is also responsible for fetching and decoding instructions from memory, as well as for managing the data flow between the various parts of the CPU.
This unit is divided into two subsections, namely, Sections of Arithmetic and Logic
The arithmetic logic unit (ALU) is a digital circuit within the CPU of a computer that performs arithmetic and logic operations on binary numbers. The ALU is a fundamental building block of the central processing unit (CPU). It is actually a complex arrangement of electronic circuitry that includes an arithmetic logic section and a control section.
Instruction Register and Pointer
The instruction register (IR) is a special purpose register that holds the instruction currently being executed. The instruction pointer (IP) is a register that contains the address of the next instruction to be executed.
Instructions are fetched from memory and stored in the IR. The IP is then incremented to point to the next instruction. This process is known as fetch-execute-cycle.
Cache
One of the most important components of the CPU is the cache. The cache is a small, fast memory that is used to store frequently accessed data.
The data in the cache is organized into small blocks, or lines, of data. When the CPU needs to access data in memory, it first checks to see if that data is in the cache. If it is, the CPU can access the data much more quickly than if it were in the main memory.
How to Test the Performance of the CPU?
There are a few ways to measure the performance of a CPU. One way is to measure the clock speed, which is the number of cycles per second that the CPU can perform.
The higher the clock speed, the faster the CPU. Another way to measure CPU performance is by measuring the amount of work that the CPU can do in a given time period. This is called throughput. The higher the throughput, the faster the CPU.
The Central Processing Unit and Its Internal Components
The central processing unit (CPU) is the brain of your computer. All of the other components, including the memory, storage, and input/output devices, work together to enable the CPU to do its job.
The CPU consists of two main components: the control unit and the arithmetic/logic unit. The control unit is responsible for fetching instructions from memory and decoding them so that they can be executed by the arithmetic/logic unit. The arithmetic/logic unit performs mathematical operations and makes logical decisions.
In addition to these two main components, the CPU also has a small amount of internal memory called a cache. The cache is used to store frequently accessed data so that it can be quickly retrieved by the CPU.
Types of Computers: Classification of Computers by Size
Computers can be classified by size and power as follows, though there is considerable overlap. The distinctions are not always clear-cut.
Microcomputers
A microcomputer is a small, relatively inexpensive computer that has its CPU on a single integrated circuit (IC). Microcomputers became popular in the 1970s and 1980s with the introduction of increasingly powerful microprocessors.
The term “microcomputer” is often used to refer to systems based on microprocessors. It is sometimes abbreviated as micro PC.
Minicomputers
A minicomputer, or midsize computer, is a class of multi-user computers that falls in size between mainframe computers and microcomputers.
Minis have confined most special-purpose industrial control applications to mainframes, but they took over many process control applications in the 1980s when advances in IC technology produced boards crammed with digital electronics that could perform control functions at a cost that was lower than for custom hardware designs.
A minicomputer is sometimes called a midrange computer or midsize computer. Abbreviated as mini, the term is not capitalized when used as part of a name for a particular system, as in DEC’s VAX mini computers or IBM’s AS/400 series mini computers. In general usage, both terms are usually lowercase.
Mainframe Computers
A mainframe computer is a large and expensive multi-user computer capable of supporting thousands of users simultaneously. Mainframes are designed for continuous operation and handle some of the largest databases in the world.
Mainframes typically use complex operating systems such as OS/390 from IBM and MVS from Honeywell Bull.
How CPU (Central Processing Unit) Works?
The CPU is often referred to as the brain of the computer, and for good reason. It is responsible for carrying out all of the instructions of a computer program. All of the data that a program need is stored in memory.
The CPU retrieves that data from memory and then carries out the instructions one by one. The interactions between the CPU and memory are managed by the computer’s bus.
1. Fetching
The first task that the CPU has is to fetch instructions from memory.
Basically, the CPU looks at the memory address that the program is currently trying to execute and grabs whatever is stored there.
2. Decoding
A central processing unit (CPU) is the hardware within a computer that carries out the instructions of a computer program by performing the basic arithmetic, logic, controlling, and input/output (I/O) operations specified by the instructions.
3. Executing
The control unit (CU) is responsible for directing the sequenced fetching and execution of instructions by controlling the other units and registers in the CPU. The CU decodes a program instruction, sets up control signals for other units, and initiates a sequence of actions that carry out the instruction.
4. Storing
4.1 Registers
The data processing unit of the CPU contains a number of storage locations called registers. A register may hold an instruction, a piece of data or the address of either. The remainder of this chapter is concerned with the data storage capabilities of the CPU.
The number, size and type of registers included in the CPU design vary between machine types. However, all CPUs contain at least one register that is used to store the address of the next instruction to be executed – this is called the program counter (PC).
Some CPUs have special purpose registers, such as:
- An instruction register (IR) that stores the current instruction being executed;
- An accumulator (ACC) for arithmetic operations;
- And index registers (X and/or Y) for use with memory operations.
5. Multi-Core Processor
A multi-core processor is a single computing component with two or more independent actual processing units (called “cores”), which are the units that read and execute program instructions.
The instructions are ordinary CPU instructions such as add, move data, and branch, but the multiple cores can run multiple instructions at the same time, increasing the overall speed for programs amenable to parallel computing.
Manufacturers typically integrate the cores onto a single integrated circuit die (known as a chip multiprocessor or CMP), or onto multiple dies in a single chip package.
A multi-core processor implements multiprocessing in a single physical package. Chips with multiple cores contain multiple processors and enable parallel execution of software threads.
Common CPU Terms
| Term | What It Means or Does |
| CPU | Central Processing Unit, or the heart and brains of the computer |
| Binary Code | A sequence of ones and zeros, or the language into which your CPU translates all data |
| ALU | Arithmetical Logical Unit, responsible for all mathematical and logical operations |
| Program Counter | Tracks which instructions the CPU should execute next when processing data |
| One hertz | The speed at which one operation is performed per second |
| Multi-core processor | A CPU with two or more independent cores, so it can do more than one thing at once |
Conclusion
A CPU, or central processing unit, is the hardware within a computer that carries out the instructions of a computer program. The CPU is responsible for all basic arithmetic, logic, controlling and input/output operations specified by the instructions.
In this article, you have learned about the different functions of a CPU and how it works. You should now have a better understanding of what goes into making your computer run.
Thanks for reading!
Leave a Reply