Unit 1.1 system architecture

Unit 1.1 system architecture

1. Computer components

   • CPU
     • Stands for central processing unit
     • Processes data
     • Houses the ALU, CU, ROM and RAM
     • Power is measured in hertz
   • Motherboard
     • Connects all other components
     • The amount of ports for various things can differ
   • GPU
     • Stands for graphics processing unit
     • Renders graphics and videos
     • Power is measured in FLOPS
       • Floating Point Operations Per Second
   • Memory
     • RAM
       • Stores current program data
       • Power is measured in bytes
       • Stands for random access memory
       • Volatile
     • ROM
       • Stands for read only memory
       • Stores the BIOS
         • Stands for Basic input/output system
         • Has instructions such as how to turn on the computer
   • Secondary storage
     • Stores data permanantly
     • Non-volatile
   • Network card
     • Connects PC to a network

2. Embedded systems

   • Embedded systems are small computer chips that are used for a simple task
   • Examples
     • Toasters
       • Uses timer
     • Washing machine
       • Stores current button presses and carries them out

3. Von Neumann architecture

   • Arithmetic logic unit
     • Preforms arithmetic and logic operation

4. CPU and fetch, decode, execute

   • Fetch
     • 1.Sends data to the MAR
     • 2.reads it and sends the data back
     • 3.The CPU copies the data from the data bus into its MDR
     • 4.the CPU copies the data from the MDR to the instruction register for decoding
     • 5.the CPU is prepared for the next step in the cycle
   • Decode
     • The CPUs control unit decodes it and sends it to the appropriate registers
   • Execute
     • The function of the data is preformed