Unit 1.1 Systems Architecture

Unit 1.1 Systems Architecture

1. Computer Components

   • CPU
     • Central Processing Unit - Processes instructions
   • Memory RAM & ROM
   • Network Card
     • Connects the computer to a network - Ethernet, Co-Axial or Wi-Fi
   • Graphics Card
     • Renders images and graphics to display
   • Motherboard
     • Connects all of the components together.
   • Secondary Storage
     • Long term storage

2. CPU & Fetch Decode and Execute Cycle

   • The way that the CPU processes its instructions.
   • It is the process by which a computer retrieves a program instruction from its memory, determines what actions the instruction describes, and then carries out those actions

3. Von Neumann Architecture

   • Control Unit
     • Tells other parts of the CPU what to do
   • Memory - RAM
     • Random Access Memory - stores instructions and data that will be used by the CPU
   • MAR
     • Memory Address Register
       • Small register that holds the address of the instructions and will start by using the RAM
   • MDR
     • Memory Data Register
       • Holds current data/instructions that are being decoded
   • ALU
     • Arithmetic & Logic Unit
       • Arithmetic is simple maths
       • Logic is comparing things and asking questions
       • Does all of the maths and calculations
   • Buses
   • Accumulator
     • Small amount of memory to remember answers from previous calculations

4. Embedded Systems

   • An embedded system ins small device often found within a larger devices which has a CPU that only does one basic task
   • Can often be found as a timer on house hold appliances such as a microwave and a washing machine