Systems Architecture

Systems Architecture

1. Von Nuemann

   • Uses a single processor
   • Uses 1 memory for both instructions and data
   • Executes programs following the fetch, decode, execute cycle
   • Based off the stored- program computer concept, where instructions data and program data are stored in the same memory
   • This concept is still used today

2. Control Unit (CU)

   • It lets the computers logic unit, memory, as well as both input and output devices Know how to respond to instructions.
   • Coordinates the CPU

3. Arithmetic Logic Unit (ALU)

   • Works out all the calculations
   • Modern CPUs contain very powerful ALUs

4. Registers

   • Current Instruction Register (CIR)
     • Holds the instruction the has just been fetched
   • Memory Address Register (MAR)
     • Holds the address of data that needs to be accessed
   • Memory Data Register (MDR)
     • Holds the data for the next instruction to be decoded
   • Accumalater (ACC)
     • Holds all the ALU data