Computer 5 logic modules:
The input device - a keyboard;
operator - basic arithmetic and logic operations;
controller - generating a control signal, the control computer generated complex functions; More Important
output device - a printer, a projector apparatus or the like;
memory - Storage cache;
5 modules are connected by data link or physical module; arithmetic unit and controller are integrated in CPU-core.
1.1.1 Digital representation of information-binary information representation
1. The computer uses digital code-binary code to represent various information
1——0001 2——0010 3——0011…8——1111 -5——1 101 and so on;
2. In the physical mechanism, use digital signals-digital electrical signals to represent digital codes.
3. The advantages of digital representation of information:
① Physically easy to display and store information;
② Strong anti-interference ability and high reliability;
③ Large range of numerical values and high precision;
④ Wide range of information that can be represented;
⑤ Usable Digital logic technology for processing-0, 1 function representation.
1.1.2 The working method of stored program-von Neumann system
1. Compile the program-compile the high-level language to form an assembler (instruction program) send to computer to realize the function;
2. Store the program-in the hard disk;
3. Automatically and continuously execute the program;
4. Output the result.
1.1.3 Computer Classification
1. Analog computer-composed of analog computing devices, capable of processing continuous analog signals (voltage, current),
divided into-dedicated computer and general purpose computer.
2. Array computer-composed of digital logic devices, processing discrete digital signals (0, 1 information).
1.2 Von Neumann Computer-the father of computers
1.2.1 The Von Neumann system laid the foundation for a modern computer theory system
1. Use binary numbers to represent programs and data;
2. Use the working method of storing programs-store programs and data, let the computer automatically execute instructions to complete complex operations-the core idea;
3. New modern computer hardware composition;
memory ——Computer-controller-input device-output device (modern technology has not escaped the shackles of these 5 modules, none of them are indispensable).
1.2.2 Computer development history
The first generation-electronic tubes-low speed, large size, poor reliability, as long as they are used for scientific calculations;
second generation-transistors-reduced size and improved reliability, from scientific calculations to data processing;
third generation- Small and medium-sized integrated circuits-reduced size, improved reliability, diversified models, the emergence of small computers, rapid development of software and peripherals, and expanded application areas; the
fourth generation-large and very large scale integrated circuits-speeds as high as DIPS or even At the TIPS level, a microcomputer appears.
1.2.3 Future development trend
1. Towards mega-development-Tianhe, Shenwei, etc.;
2. Toward miniaturization;
3. Towards multimedia-to improve user experience;
4. Towards network;
5. Towards intelligence-lazy applications, mobile phones and many more.
1.3 Organization of the computer system
Hardware -tangible equipment such as entities and devices that constitute a computer system ; material basis -hard equipment;
software -various internal information expressed by hardware, including data and control programs. Intangible things -soft equipment.
1.3.1 Computer hardware system composition
1. The basic composition model of the hardware system is basically not used now
Main functions: 1.
CPU -mainly composed of arithmetic units, controllers and other components.
2. Calculator
(1). Function-complete arithmetic and logical operations.
(2). Composition characteristics
①It is mainly composed of ALU (arithmetic logic unit), which performs arithmetic, logical operations and shift cycles, and is the main execution part of the CPU function;
②ALU takes full adder as the core and has multiple computing functions ;
③ more bits of the operation, the higher the calculation accuracy (binary multiple), the more complex the device;
data width is generally operator ④: 8-bit, 16-bit, 32-bit or64;
3. Controller
function-generate control commands (micro commands) to control the operation of the whole machine. When the CPU executes a command, the controller cannot actively execute the command and requires some controllers to cooperate.
basic component:
4. Memory
Features-working speed is faster, storage capacity is smaller than external memory.
Function-store data and digitized program.
Attention: Whether it is data or program, the memory stores all 0 and 1 codes .
①Storage unit — storing n storage circuits of an n-bit binary number in the memory to form a storage unit;
②Address —the memory is composed of many storage units, and the number of each storage unit is called address;
③Storage capacity
——The total number of all storage units of the memory; the larger the storage capacity, the more information is stored. Commonly used units are-KB, MB, GB, TB, PB, etc.;
④ Internal memory -the main memory, which is a kind of Used to store the program and data memory that directly provide services for the CPU-composed of semiconductor chips;
⑤ External memory -that is, auxiliary storage, auxiliary storage with a large memory capacity for the computer.
Disk storage, optical disk storage, etc., are mainly characterized by large storage capacity, reasonable price, and slow working speed.
5. Input and output equipment
function-to perform the conversion of input\output information.
When inputting : original information -> binary code, sent to the host;
when outputting : processing result (binary code) -> the form (characters, images, sound) that the user can directly perceive, and transmit to the user.
4. Bus -a group of information transmission channels that can be time-shared by multiple components.
There are three types of buses-data bus, address bus, and control bus.
5. Interface
Each interface is attached with the destination address and source address of the IP datagram. The connection between the two routers shares the same interface address.
Typical architecture of computer hardware
1. Microcomputer: South-North Bridge Architecture
2. Small computer: multi-processor architecture-understand
HP HP ProLiant DL30 series
3. Supercomputer (supercomputing): cluster architecture-Tianhe-2, Shenwei
Multi-processor system structure:
Features-It is composed of multi-processor CPU;
according to the degree of tightness of the connection of the processor, it can be divided into:
tightly coupled multi-machine system and loosely coupled multi-machine system
tightly coupled multi-machine system:
Features-Multiple (CPU+LM) groups, which form a multi-machine system through the system bus, and share the global main memory.
Loosely coupled multi-machine system:
Features-Multiple computing nodes, a multi-computer system connected by a communication system, without a global main memory.
1.3.2 Software System
Software category—system program and application program:
①System program—responsible for system electroplating management, providing operation and development environment, various services to ensure that the system runs well;
②Application program—program compiled by using a computer to solve application problems , Such as engineering design program, data processing program, automatic control program, enterprise management program, information retrieval program, scientific calculation program, etc.
1.3.3 Software and hardware system hierarchy
The computer system is composed of a multi-level software + hardware system, the basic structure is as follows:
1.3.4 The logical equivalence of software and hardware
① Features of software-easy to implement various logic and calculation functions, but often restricted by speed indicators and software capacity;
② Features of hardware-can realize logic and calculation functions at high speed, but it is difficult to implement complex functions or calculations and is controlled Constraints of complexity indicators.
The software in the computer can theoretically be "cured" or "hardened" into hardware to increase the execution speed, resulting in complex and increased hardware structure and cost.
1.4 Performance indicators of computer systems
1. Basic word length
①The basic digits of a data operation;
②It will affect the accuracy of calculation and the function of the instruction.
2.
External frequency External frequency or base frequency, also called system clock frequency.
3. Commonly used CPU performance indicators
①CPU main frequency = FSB** multiplication factor*;
②IPS, the number of instructions executed per second;
③CPI, the number of clock cycles used to execute an instruction, the larger the CPI, the instruction cycle the program needs to execute The more the number is;
④FLOPS, the number of floating point operations performed per second. The larger the FLOPS, the more floating-point operations performed by the CPU per unit time, and the better the CPU performance;
⑤CPU power consumption.
Static power consumption- CPU semiconductor composition, loss of current and voltage, and its own loss;
dynamic power consumption-power consumed by the CPU to perform arithmetic operations;
P = C × U^2 × f C-load capacitance U- —Working voltage f——Working frequency
4. Data transmission rate-bandwidth
bandwidth = (bit width × operating frequency)/8 (B/S)
Physical meaning -how much data is transferred per unit time.
Attention: When calculating the bandwidth of the PCI-E bus, the encoding method, but the duplex mode and the number of channels are generally considered.
5. Memory capacity
①Memory/main storage capacity = number of addressable storage units (depending on the number of digits of the address code) * bit width of the storage unit (indicating the addressing unit;
② external storage/auxiliary storage capacity—— The maximum amount of data that the memory can store (external memory-U disk or the like);
often expressed as-Byte, KB, MB, GB, TB. The
amount of external memory has nothing to do with the number of bits of the bus address code, so the external memory can Unlimited
Persist in learning, relatively hard, but absolutely excellent.