Csc 2

• CPU

  The brain of the computer where all the arithmetic calculations and logical operations take place
• Topics Covered in Session 1

  • Input Unit
  • Memory Unit
  • Output Unit
  • Control Unit
  • ALU
  • Registers
  • Computer System Block Diagram
• CPU or Processor


  • The brain of the computer system
  • It provides the processing power to the computer
  • It controls the hardware and executes computer programs

  
• CPU or Processor


  • Intel
  • AMD

  
• How the CPU works

  1. Fetch data and instructions from RAM

  2. Decode the instructions

  3. Execute the instructions (perform calculations)

  4. Store data in memory
• CPU Functions

  • Controls all the activities of the computer system
  • Executes programs
  • Fetch data and instructions from RAM
  • Decode the instructions
  • Execute the instructions (perform calculations)
  • Store data in memory
  • Controls the working of Hardware (receive data from keyboard, send signals to HardDisk, send instructions to RAM, send data over network, Solve errors, etc)

  
• Control Unit (CU)


  Directs all the operations of the processor<|>Directs ALU, input/output devices, and the memory<|>Decode programs instructions and generates the necessary signals for ALU
• Arithmetic Logical Unit (ALU)


  Performs arithmetic calculations and logical operations<|>ALU performs the desired operation on data (as per the operation code OP generated by CU)
• Memory Unit


  CPU needs high speed memory area to store the frequently used data during the program execution<|>Registers: used to perform operations on data (ex: to store numbers before using them in ALU)<|>Cache Memory L1: used to store frequently used data and instructions
• How the CPU executes a program

  1. Fetch program instructions one by one from the main memory (RAM)

  2. Decode the instructions

  3. Load 7 and 4 to registers

  4. Send an order to ALU to add them
• The CPU controls the working of RAM