1.1 Systems Architecture

1.1 Systems Architecture

1. CPU

   • What is the purpose & function of the CPU?
     • To fetch, decode & execute instructions.
       • Fetch, Decode & Execute Cycle
     • To process data.
   • What is it made up of?
     • CU - Control Unit
       • What is the CU?
         • It controls the flow of data through the system
         • It controls & moniters communications between the hardware.
         • It controls the input & output of data.
     • Immediate Access Store
       • What is it?
         • It holds all the data & programs that it is currently using.
         • It can also be referred to as registers.
           • What is a register?
             • A component for holding short term memory.
             • Used to store addresses or data that is currently being used.
               • What is an example of a register?
                 • MAR - Memory Address Register
                 • Used to store the address of the next instruction.
     • ALU - Arithmetic & Logic Unit
       • What is the ALU?
         • It performs the arithmetic & logic calculations.
         • Every task that your computer carries out is copleted here.
         • What parts do the ALU's operations fall into?
           • The Arithmetic Part - deals with calculations (eg. 1 + 2 = 3) (eg. + - x)
           • The Logic Part - deals with any logical comparisons (eg. 2 > 1) (eg. > < )
     • There is also cache.
       • A tiny block of memory in the processor.
   • CPU - Central Processing Unit
   • AKA. Processor

2. What affects the preformance of the CPU?

   • Clock Speed
     • What are the effects of having a faster clock speed?
       • More instructions are carried out per second.
       • Allows more programs to be run at the same time.
   • Cores
     • What are the effects of using more cores?
       • More instructions are carried out simultaneously.
       • Allows more instructions to be processed at the same time.
       • Allows more programs to be run at the same time.
   • Cache Size
     • What are the effects of having more cache?
       • More space for frequently used instructions.
       • More storage so you can access items faster.
       • And so instructions a fetched faster.

3. Embedded Systems

   • What is an embedded system?
     • A computer system that is built into another device.
   • What is the purpose of embedded system?
     • To provide specific functions which is cheaper than providing a personal computer system.
   • What are some examples of embedded systems?
     • Sat Nav
     • MP3 Player
     • Washing Machine