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Editor to share with you what is the working principle of CPU, I believe that most people do not know much about it, so share this article for your reference, I hope you can learn a lot after reading this article, let's go to understand it!

Every time cpu executes an "instruction", it completes a basic operation or judgment. In CPU, the operation of an instruction includes three steps: fetch, analyze and execute, so executing an instruction will complete a basic operation or judgment.

Cpu performs basic operations by executing "instructions". Every time the CPU of a computer executes an "instruction", it completes a basic operation or judgment. In CPU, the operation of an instruction includes three steps: fetch, analyze and execute, so executing an instruction will complete a basic operation or judgment.

Central processing unit (CPU) is one of the main equipment of electronic computer and the core accessory of computer. Its main function is to interpret computer instructions and process data in computer software. CPU is the core component in the computer which is responsible for reading instructions, decoding instructions and executing instructions. The CPU mainly consists of two parts, namely, the controller and the arithmetic unit, including the cache memory and the data and control bus to realize the relationship between them. The three core components of electronic computer are CPU, internal memory and input / output equipment. The main functions of the CPU are processing instructions, performing operations, controlling time, and processing data.

In the computer architecture, CPU is the core hardware unit that controls and allocates all the hardware resources of the computer (such as memory, input and output units) and performs general operations. CPU is the core of computer operation and control. The operations of all software layers in a computer system will eventually be mapped to CPU operations through instruction sets.

How CPU works

Von Neumann architecture is the foundation of modern computers. Under this architecture, programs and data are stored uniformly, instructions and data need to be accessed from the same storage space, transmitted through the same bus, and can not be executed overlapping. According to the von Neumann architecture, the work of CPU is divided into the following five stages: instruction fetch phase, instruction decoding phase, instruction execution phase, access number and result write back.

IF,instruction fetch, the process of fetching an instruction from the main memory to the instruction register. A value in a program counter that indicates the location of the current instruction in main memory. When an instruction is fetched, the value in PC is automatically incremented according to the length of the instruction word.

In the instruction decoding phase (ID,instruction decode), after fetching the instruction, the instruction decoder splits and interprets the retrieved instruction according to the predetermined instruction format, and identifies different instruction classes and various methods to obtain operands.

The execution instruction phase (EX,execute), which realizes the function of the instruction. Different parts of the CPU are connected to perform the required operations.

The access number stage (MEM,memory) accesses the main memory and reads the operands according to the instruction. CPU gets the address of the operands in the main memory and reads the operands from the main memory for operation. If some instructions do not need to access main memory, you can skip this stage.

The result writeback phase (WB,write back), as the last phase, "writes back" the run result data of the execution instruction phase to some storage form. The resulting data is generally written to the internal register of CPU so that it can be quickly accessed by subsequent instructions; many instructions also change the state of the flag bits in the program status word register, which identify different operation results and can be used to influence the action of the program.

After the instruction is executed and the result data is written back, if no unexpected event (such as result overflow, etc.) occurs, the computer obtains the address of the next instruction from the program counter and starts a new cycle. The next instruction cycle will sequentially fetch the next instruction.

These are all the contents of the article "how does CPU work?" Thank you for reading! I believe we all have a certain understanding, hope to share the content to help you, if you want to learn more knowledge, welcome to follow the industry information channel!

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