Computer Systems - Von Neumann Architecture

Question 1

What is the Von Neumann architecture?

Answer 1

A system where the CPU runs programs stored in memory - the programs consist of instructions and data which are stored in memory addresses

Question 2

What do arrows in the Von Neumann architecture represent?

Answer 2

The flow of data through buses

Question 3

Describe a simplified version of the Von Neumann architecture

Answer 3

CPU in the middle (as a rectangle) - Control Unit (top left), ALU (top right), registers (below) each connected by buses flow to and from each other (2 arrows connected each one)
Input device (below the CPU) - data from buses only goes to the CPU (1 arrow)
Memory (on the left of the CPU) - data from buses flows both ways (2 arrows)
Output device above the CPU - data from buses only flows from the CPU (1 arrow)

IS SUBJECT TO CHANGE A BIT

Question 4

What do the Control Unit (CU) do in the Von Neumann architecture?

Answer 4

1. Controls the flow of data
2. Keeps track of the memory address of the instruction for each cycle

Question 5

What does memory do in the Von Neumann architecture?

Answer 5

Holds the program instructions and the program data

Question 6

What do registers do in the Von Neumann architecture?

Answer 6

Hold any data, instructions and memory addresses that are about to be used by the CPU.

Question 7

Why are there specific registers in the Von Neumann architecture?

Answer 7

Specific registers are for different tasks - e.g one that holds data about to be used by the CPU

Question 8

What does the ALU do in the Von Neumann architecture?

Answer 8

1. Gets data from the Control Unit and registers
2. Performs an operation on that data
3. Sends the output to the registers

Question 9

What are one of the main features of the Von Neumann architecture?

Answer 9

It only uses 1 memory for both data and the instructions