1.1 sys architecture

1.1 sys architecture

1. components

   • alu
     • Performs logical operations (AND, OR, NOT), Shift operations and Arithmetic operations (+,-, *, / )
   • cache
     • Sits between the CPU and RAM. Usually built into the CPU. Very fast. Holds frequently used data so that the processor doesn’t have to keep going back and forth to the RAM.
   • control unit
     • Controls activities in the CPU (Such as flow of data between CPU and other parts). Makes FDE cycle happen in correct order

2. purpose of the cpu

   • Central processing Unit – This processes all of the data and instructions that make a computer system work

3. fde cycles

   • fetch
   • decode
   • execute
   • Fetches instructions and data from memory and brings them back to the CPU to be decoded and executed (run)

4. registers

   • accumilator
     • Stores the results of the calculations done by the ALU
   • pc
     • Holds the memory address of the instruction for each cycle. It has the easiest job because it points to the first instruction for each cycle.
   • mdr
     • Holds data or instructions that have been fetched from memory. Remember - MAR stores Address, MDR stores Data.
   • mar
     • Holds memory address about to be used by the CPU. Remember - MAR stores Address, MDR stores Data.