1.1 System Architecture

1.1 System Architecture

1. Embedded systems

   • A computer system with a dedicated function with a larger mechanical or electrical system.
   • Microwave- To countdown the time when heating.
   • PS4 controller- To connect to the PlayStation to allow the controller to sense vibrations from gameplay.

2. Computer Components

   • CPU- Processes and conducts instructions given by a computer programme running on the computer.
   • Motherboard- Holds and allows communication between components of the system.
   • GPU- An expansion card which generates a feed of output images to a display.
   • Memory- A distinction from storage that provides slow-to-access information but offers higher capacities.
   • Secondary storage- Non volatile memory that is not directly accessible by the CPU because it is access by the Input/Output channels.
   • Network Card- Hardware component that connects a computer to a computer network.
   • Cache Memory- Inside the processor chip which makes it much faster to use compared to other memory (RAM). Acts as the first point of contact when looking to find data stored in the memory.

3. CPU & Fetch, Decode and Execute

   • CPU- Processes and conducts instructions given by a computer programme running on the computer.
   • 1. The processor checks the program counter to see which instruction to run next.
   • 2. The programme counter gives an address value in the memory of where the next instruction is.
   • 3. The processor fetches the instruction value from this memory location.
   • 4. Once the instruction has been fetched, it needs to be decoded and executed. This could involve taking one value, putting it into the ALU, then taking a different value and adding the two together.
   • Once this is complete, the processor goes back to the programme counter to find the next instruiction.
     • A programme counter is a register in a computer processor that contains the address (Location) of the instruction being executed at the current time. As each instruction gets fetched, the programme counter increases its stored value by 1

4. Von Neumann Architecture

   • MAR- Memory Address Register
   • MDR- Memory Data Register
   • The CU is responsible for controlling how the other sections of the CPU will work and how they respond to instructions.
   • The CU is also responsible for maintaning the MDR and MAR.
   • The ALU is the part of the CPU that performs the calculations that are required for instructions.
   • Calculations are in two groups.
     • Arithmetic calculations (Addition, subtraction, division, multiplication)
     • Logic calculations ( is 5>3? , does 2=4?, is 11<9?)
   • The Accumulator is a small amount of memory to remember the answers from previous calculations if they need to be used in the future.