Every computer has two big blocks-hardware and software.
The so-called hardware refers to the visible and tangible machine parts. The computer we see has some cabinets or cases filled with all kinds of electronic equipment, plus keyboards, mice, monitors and printers, all of which are hardware.
The so-called software is the general name of programs and related documents. A program consists of a series of instructions, and each instruction can generally stimulate the machine to perform the corresponding operation. Computer experts compare the execution of programs in machines to the cooking of chefs, and menus are programs. The cook followed the recipe step by step until the dish was ready. The result of menu execution is a dish, the result of program execution is an output with a certain format, and the document is an auxiliary text material related to the program.
The central processing unit (CPU) is one of the core components of an electronic computer, and it is the component that completes the reading, interpretation and execution of instructions in the computer. In the hardware system of the computer, there are two key components besides the input and output devices and the memory, namely the arithmetic unit and the controller. The performance of these two components often determines the performance of the whole computer system, and they are most closely related, so they are often combined. The arithmetic unit and the controller are called the central processing unit, which is the Chinese translation of the English control processor. We usually take the first letters of three English words to synthesize CPU. In modern microcomputers, CPU is often combined on one chip, which is the most critical part of the computer and is made of integrated circuit technology.
Experts collectively refer to CPU and memory as the host, which is equivalent to the human brain. It is used to remember events, analyze and judge operations, control the coordination of various parts, and accurately complete specific tasks.
Input and output devices are called external devices, or simply peripherals. They are just bridges between communication and the host, such as the sensory organs that receive information and the bodies that send out actions.
The importance of CPU in computer is incalculable, and people call it "the heart of computer" vividly. CPU is also commonly called microprocessor, which includes arithmetic unit, register, accumulator, arithmetic logic unit, control unit, clock generator, internal bus and so on.
Arithmetic unit is the heart of the heart, and it is a processing factory where computers process information to form new information. Its main function is to complete arithmetic operation, logical operation and logical judgment on data, so it is also called arithmetic logic unit.
There are several registers in the arithmetic unit that can store data. During the operation, under the unified command of the computer controller, the memory or register provides the required information for the operator to perform addition and subtraction arithmetic operations or other operations. Depending on the situation, the operation results are either temporarily stored in internal registers or sent back to memory.
The arithmetic unit is mainly composed of an adder, several registers and some control circuits.
The controller is the nerve center of the computer and directs the whole machine subsystem to work automatically and harmoniously. Specifically, it first fetches an instruction from the memory, then analyzes the instruction, points out what kind of operation the instruction needs to complete, and indicates the address of the operand. Finally, according to the address of the operand, the operand is taken out to complete some operation. That is to say, the process from obtaining the instruction to completing the task given by the instruction generally goes through three stages: fetching data, analyzing and executing, and each stage contains more small tasks, which are arranged at different times and completed in a shorter time interval.
The main components of the controller are: instruction register, which is responsible for registering instructions; A decoder for translating the operation code in the instruction into a corresponding control signal; The timing beat generator generates certain timing pulses and beat potentials to make the computer work rhythmically and orderly; The operation control part combines the pulse, potential and control signal of the decoder to timely and orderly control all parts to do corresponding operations; Instruction calculator, pointing out the next instruction.
The 486 and 586 computers we usually talk about are all relative to the function of CPU; Advanced computers such as biological computers in the future often refer to the improvement of CPU processing. In this sense, the progress of CPU represents the progress of computer.