Von Neumann architecture

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Knowledge point

1. Von Neumann architecture is right Hardware components and software execution methods Two parts make provisions .
2. Five hardware of computer （ Von Neumann ）： Arithmetic unit 、 controller 、 Memory 、 input device 、 Output devices .
3. Arithmetic units and controllers are collectively referred to as Central processing unit CPU The core of the computer 、 The brain .
4. Program = data + Method , The procedure is made by CPU Executive .

Arithmetic unit

You can only add .

controller

Assign the work of the arithmetic unit .

Memory

1. The memory should conform to the following two points
   • Can store data .
   • The program in the storage space can be called directly by the arithmetic unit .
2. Hard disk 、U Disk does not belong to memory , Does not meet the second point , It belongs to external memory , It also belongs to input and output devices .
3. Memory is memory , Memory refers to memory .

Memory

1. Memory includes ： Memory module 、 Cache (cache)、BIOS chip
2. BIOS： Basic I / O device , There are separate BIOS Chip storage BIOS Program .
3. ROM： read-only memory , Power failure without losing data .
4. RAM： Ram , Loss of data due to power failure , Volatility .
5. ROM and RAM All the programs in will be executed .
6. BIOS The chip belongs to ROM, Memory modules and caches belong to RAM.

Input / Output devices （I/O）

1. input device ： keyboard 、 mouse 、 Scanner, etc .
2. Output devices ： Monitor 、 The printer 、 Projector, etc .
3. Input / The output device consists of CPU management , But not with CPU Direct link , Need to pass through I/O Interface .
4. Input / The output device contains I/O Interface and peripherals are two parts .

Program operation process

1. download / The installer is to install the program in the local hard disk , Any program cannot run when it is in the hard disk , Follow the following steps when starting the program
2. Read and write the program in the hard disk to the memory , Load memory .
3. CPU The arithmetic unit in executes the program in memory , Show the working area of the program on the desktop .
4. When you exit the program , The program will not disappear from memory .

Mobile phone structure

1. The mobile phone also adopts von Neumann structure , Mobile phones are embedded products .
2. Mobile phone memory is divided into ： Running memory and body memory .
3. Run a memory ：RAM
4. Body memory ：ROM
5. The program in the body memory can be directly CPU call , The program is in Data generated at run time Is stored in Run a memory Medium .

General purpose devices and embedded devices

1. General equipment ：CPU from RAM Read instructions in , At the same time RAM Read data from .
2. Embedded device ：CPU from ROM Read instructions in , from RAM Read data from .

Memory structure

1. Harvard structure ： Instructions and data are stored separately . Most embedded devices are Harvard architecture .
2. Von Neumann structure ： Instructions and data are stored uniformly , All put in RAM in . Most general-purpose devices are von Neumann structures .
3. Memory structures are divided into the above two , But there is only one computer structure , That is the von Neumann architecture .

Way of execution

The binary program is used to store the execution method

The transistor

1. Transistors are divided into two-stage transistors and three-stage transistors .
2. Its main function is to act as a switch .