Computing

• The CPU, or central processing unit, is the primary component of a computer that performs most of the processing inside the computer.
• A computer is an information processing machine capable of acquiring, storing, transforming, and restoring information
• Von Neumann's model decomposed the computer into 4 distinct parts:

  • Arithmetic and logical unit (ALU) or Processing Unit: performs basic operations
  • Control unit: equivalent to fingers actuating a calculator
  • Memory: contains data and programs for the control unit
  • Input-output devices: communicate with the outside world
• A program is a sequence of basic instructions executed sequentially by the processor
• Main memory consists of numbered cells holding small amounts of information

  • RAM (Random Access Memory): stores intermediate data, lost when power is off
  • ROM (Read Only Memory): stores programs, retains data without power
• Only the processor can change the state of memory

  • Operations on memory: writing in a location and reading from a location
• The Central Processing Unit (CPU) is composed of the microprocessor responsible for interpreting and executing instructions, reading or saving results in memory, and communicating with exchange units
• Arithmetic and Logic Unit (ALU) performs elementary operations, logical operators, and comparison operations
• Registers are small, fast internal access memories used to temporarily store data, instructions, or addresses
• Control Unit facilitates communication between ALU, memory, and peripherals, sequences instruction flow, and performs memory instruction search
• The first step in designing a microprocessor is defining its instruction set, describing elementary operations it can perform
• Instructions types include data transfer, arithmetic operations, logical operations, and sequence control
• Instructions and operands are stored in main memory, coded on an integer number of bytes for processor decoding
• I/O Interfaces allow communication between the computer and external devices
• Processor-Memory links include address bus, data bus, and control bus for information exchange
• Memory is a semiconductor circuit for recording, storing, and retrieving information
• Memory is divided into bytes, each accessible independently with a unique address
• Memory characteristics include capacity, data format, access time, cycle time, rate, and volatility
• Memory hierarchy includes registers, cache memory, main memory, and buffer for data storage and access acceleration
• Registers are the fastest memory elements used to store operands and intermediate results
• Cache memory accelerates access to central memory by storing frequently used data
• Main memory contains programs and data, slower than registers and cache memory
• Buffer memory is a temporary holding place for data being sent to or received from external devices
• Mass memory, also called secondary or auxiliary memory, is designed to store large amounts of data
• Mass memory is also known as secondary memory or auxiliary memory, used for storing large amounts of information
• It is a high-capacity peripheral memory used for permanent storage or backup of information
• Common auxiliary memories include hard disks, optical discs (CDs and DVDs), USB sticks, and memory cards
• The system clock is used to synchronize the operations of a computer
• It schedules the processing of instructions by the microprocessor or the transmission of information on different buses
• Increasing the clock speed generates more heat by the processor, which can lead to damage
• There is a limit to the speed of the clock to prevent the processor from becoming unstable and generating errors
• A computer bus is a communication system between the components of a computer
• It includes the material constituting the communication medium and the software
• Buses can be parallel (e.g., printer, USB scanner) or serial (e.g., keyboard, mouse)
• Ports are hardware components that allow the system to communicate with external elements
• There are internal ports for connecting expansion cards or storage devices and external ports for connecting other devices
• Expansion cards are used to add features or increase the performance of a computer
• Common expansion cards include graphics cards, sound cards, network cards, and memory cards
• Peripheral devices are connected to a computer system to add functionality
• There are storage devices for mass storage and I/O devices for interaction with the user