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Working principle and hierarchy analysis of von Neumann structure computer

<1> Introduction to von Neumann

  • EDVAC(Electronic Discrete Variable Automatic Computer)
  • Father of the computer
  • One of the world’s foremost mathematicians
  • Member of the American Academy of Sciences (major contributions to modern computer and game theory)

<2> How the von Neumann computer works

  • Stored program
    • To store programs in the memory of a computer
    • Storage system building and fast access
  • Program control
    • Access the memory according to the instruction address and take out the instruction, and generate the control signal required by the instruction execution through decoding, so as to realize the control of the calculation and complete the function of the instruction
    • Instruction system, controller design, etc

<3> Composition of von Neumann computer (hardware + software)

1. Hardware system (general picture)

  • Host: CPU(arithmetic unit + controller) and memory
  • Peripherals: input device, output device, external memory
  • Bus: address line, data line, control line

(1) Hardware system – arithmetic unit

  • Arithmetic operations: addition, subtraction, multiplication, division, etc
  • Logical operations: and, or, not, shift, etc
  • The basic structure
    • ALU (Arithmetic Logical Unit) : Arithmetic Logical Unit
    • register
    • Connecting path

Focus on functional versus structural relationships – instructions, data types, performance requirements, and so on

(2) Hardware system – controller

  • Generate all the control signals required by the instruction execution process, and control relevant functional components to perform corresponding operations
  • Control signal form
    • Level signal
    • The pulse signal
  • The basis on which control signals are generated
    • instruction
    • state
    • The sequential
  • Controls how signals are generated
    • The micro program
    • Hard wiring

(3) Hardware system – memory

  • function
    • Store the original program, original data and intermediate results of operation
  • Way to work
    • Read/write
  • The working principle of
    • Access by address, read/write data

(4) Hardware system – input/output devices

  • Input devices
    • Enter data into a computer (keyboard, mouse, nic, scanner, etc.)
  • Output devices
    • Output processing results (display, sound card, network card, printer, etc.)

2. Software system

Understanding of software

  • Operational digitization of ideas and content

Ideas: algorithms, rules, methods – programs express content: graphics, images, data, sound, text and other objects to be processed

  • Presentation of software: programs and data (information in binary form)
  • The core of the software: algorithms
  • The system software
    • Such as operating systems, network systems and compiler systems
  • Support software
    • Development tools, interface tools
  • Application software
    • Word processing software: Office
    • Game software

3. The relationship between hardware and software systems

  • interdependence
    • Hardware is the foundation on which software runs
    • The normal operation of software is an important way for hardware to play its role
  • Logical equivalence
    • Some functions can be implemented by hardware as well as software
  • Collaborative development
    • Software develops with the rapid development of hardware technology
    • The constant development and improvement of software promotes the updating of hardware
    • Both closely interweave development, one is indispensable

<4> Hierarchy of computers

  • Different users are at different levels
  • Different levels have different attributes
  • Different layers use different tools

  • Code efficiency is different at different levels

1. Concept of transparency

  • Things or properties that exist, when viewed from a certain Angle, do not appear to exist
  • For example, the characteristics of the hardware are transparent to the C language programmer

2. The system concept

  • When hardware architecture changes, think about the possible impact on software
  • Different types of software have different requirements for hardware
  • Programming CPU hardware relevance, programming should refer to the corresponding CPU programming manual

3. Hardware and software boundaries

  • Where is the dividing line?
    • Instruction set architecture layer
  • The dividing line is the interface between hardware and software. It is the interface for instructions to operate hardware
  • Instruction format and instruction design are associated with hardware

The CPU hardware dependency, programming should refer to the corresponding CPU programming manual

3. Hardware and software boundaries

  • Where is the dividing line?
    • Instruction set architecture layer
  • The dividing line is the interface between hardware and software. It is the interface for instructions to operate hardware
  • Instruction format and instruction design are associated with hardware

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