1.1 System Architecture

1.1 System Architecture

1. FDE Cycle

   • Decode: Instruction is decoded
   • Fetch: Instruction is fetched from RAM
   • Execute: Instruction is sent to CPU and is executed
   • This cycle is repeated x times a second, measure in Hertz (Hz). Computers can run at around 1 GHz, or 1,000,000,000 cycles a second.

2. Components & CPU

   • Control Unit (CU): controls the flow of data from x to y
   • Cache: accesses frequently accessed instructions quickly
   • ALU: performs calculations
   • MAR: holds the address of the current instruction
   • MDR: Holds the data of the current instruction
   • PC: Holds the address of the next instruction
   • ACC: Holds the results of calculations from ALU

3. Factors That Affect The CPU

   • Clock Speed: no. of instructions performed a second
   • Number of Cores: no. of simultaneous instructions performed
   • Cache Size: the memory that is fast access

4. Embedded Systems

   • Examples of Embedded Systems include: microwaves, traffic lights, washing machines
   • An embedded system is a computer built into a larger system
   • An embedded system has a micro processer, and specifically does one task