COMP SCI

• CPU


  Central processing unit

  - the brain of the computer

  -controls the other elements of the computer
• CU


  Control Unit

  - manages instructions

  - FDE cycle

  - sends control signals controlling hardware

  - moves data around
• ALU


  Arithmetic Logic Unit

  - performs arithmetic/logical operations (calculations and decisions made)

  - gateway between primary/2ndary storage
• RAM


  -Random Access Memory

  -VOLATILE (lost when computer turned off)

  -constantly being written to/read from
• ROM


  -Read Only Memory

  -NON-VOLATILE (keeps data)

  -contains bootstrap programs
• Cache


  - small amount of high-speed RAM

  - temporarily stores instructions/data that processor is likely to reuse

  - allows faster processing as processor doesn't need to fetch instructions from actual RAM
• Registers


  - small amounts of high-speed memory in CPU

  - stores data needed in processing (eg. Next instruction addresses, current instructions, rest of calculations)

  - Different processors have different numbers of registers
• LEVEL 1 CACHE


  Fast rates but small in size

  Processor uses L1 to store most used instructions/data
• LEVEL 2 CACHE


  Bigger than L1 Cache but slower

  Holds instructions/data used less frequently
• The five types of registers (in Von Neumann architecture)?


  Program counter (PC)

  Memory Address Register (MAR)

  Memory Data Register (MDR)

  Current Instruction Register (CIR)

  Accumulator (ACC)