1.1 Systems Architecture

1.1 Systems Architecture

1. Cache

   • Stored in the CPU
   • Faster then RAM but slower than the registers (MAR and MDR)
   • Stores data that the CPU needs to access quickly (regularly used data)
   • Cache is the first place checked for data, because it's closest. If not, it goes to the RAM, then eventually the hard drive
   • Low capacity and very expensive
   • Cache comes in 3 different levels. L1 is fastest but has the lowest storage. L3 is slowest but has the most storage

2. Control Unit

   • Has overall control over the CPU
   • executes the instructions taken from the Fetch-Decode-Exectute cycle.
   • Controls the data flows inside the CPU

3. Arithmetic Logic Unit (ALU)

   • Does all of the calculations
   • Does basic addition and subtraction and does multiplication and division via repeating the adding and subtracting
   • Also carries out the logic based functions: AND, OR and NOT, as well as various binary shifts
   • Also houses the accumulator

4. CPU

   • The brain of the computer system
   • Acts as the main processor, taking in every bit of data and/or instruction to allow the system to function