Systems Architecture

• Hardware


  The parts of the computer you can touch
• Software


  The programs that control the computer
• The CPU (Central Processing Unit) is responsible for processing instructions
• A "stored-program" system is a computer that stores program instructions in electronic memory
• The CPU executes programs, manages messages sent to hardware and dictates where in the memory data is stored
• The arithmetic/logic unit (ALU) performs calculations and processes logic operations
• The control unit (CU) controls data movements and the timing of processes
• Cache

  The memory unit is responsible for storing data and instructions
• Cache is a small section of very fast memory on the CPU
• Data is held in the cache to speed up the execution, so it does not have far to travel from the main memory to the processor
• Clock speed is measured in hertz (Hz) and describes the cycles per second
• A core is an independent processing unit within a CPU
• Purpose of embedded systems

  Embedded systems are computerised circuits that have been created for one specific purpose. The circuits are created to perform specific tasks and cannot be re-programmed to perform something else.
• Advantages of embedded systems

  • Easy to make for mass production
  • Highly reliable as it can be thoroughly tested to perform a few specific tasks
  • Tend to be smaller in size
  • Less expensive to manufacture as they are less complicated to make
  • Often faster than standard computer systems
  • Uses less electricity
• Disadvantage of embedded systems

  It is not possible for it to be improved later and a new embedded system must be created if there are updates