06 - Von Neumann Architecture

 1. Early computers were used for code breaking. If there was then a need for them to be used for something else, it would take a complete ______________ by hand (a long process). There was no such thing as a quick update!





 2. It was the famous scientist John Von Neumann that came up with an idea that made computers far easier to update and change. (this is a simple definition) This is called the:

  Neumann Excellento

  Turing Complete Architecture

  Von Neumann Architecture

  Von Dam Computer

 3. Von Neumann's _____________ _____________ _______________ was an amazing discovery. It meant that the data to be used as well as the software (instructions) could both be stored in the computer's memory (RAM).
Further Notes: 

Von Neumann architecture was first published by John von Neumann in 1945.

His computer architecture design consists of a Control Unit, Arithmetic and Logic 
Unit (ALU), Memory Unit, Registers and Inputs/Outputs.

Von Neumann architecture is based on the ____________________________, 
where instruction data and program data are stored in the same memory.  
This design is still used in most computers produced today.

  stored program computer or stored program concept

  stored procedural computation

  stoppable computable procedure

  string program CPU

 4. What is one obvious advantage to having a stored program computer as opposed to the older computers that did not incorporate this concept?
The task a computer is working on can be changed by simply loading a different program
into memory

The memory of a computer can be changed by simply loading data into it

The computer can be updated easily by re-wiring the entire system by hand. 

  #1 and #2

  #2 and 3



 5. The ________________ was the first fully electronic computer to run a stored program. It ran a factoring program for 52 minutes on June 21, 1948, after running a simple division program and a program to show that two numbers were relatively prime

  Samsung Laptop with a i7 CPU

  Windows PC version 8.9

  Apple iphone 8

  Manchester Baby

 6. Read the excerpt below that outlines the main features of the Von Neumann Architecture. Fill in the blanks for point #2.
Three things you need to know about the Von Neumann Archicture

*Remember it is not a computer itself, just an idea/concept

#1 Uses a single processor.

#2 Uses one memory for ______________________________________

(note: A von Neumann computer cannot distinguish between data and instructions in a memory location!
It ‘knows’ only because of the location of a particular bit pattern in RAM.)

#3 Executes programs by doing one instruction after the next in a serial manner using a 
fetch-decode-execute cycle.

  instructions alone

  both instructions and data

  data alone

  all calculations

 7. We also know that the Von Neumann computer has an IAS, or Immediate Access Store, where it puts both programs and data. We often commonly refer to this memory as _______





 8. With the success of the Von Neumann Architecture why would anything else be needed? There was however a rival architecture called the "Harvard Architecture". This idea involved:

  keeping data and instructions in seperate memory

  keeping both data and instructions in the ROM

  keeping the data in the ALU and the instructions in the heat sink

  keeping data and instructions in the same memory like the von neumann architecture

 9. Read the following excerpt that explains the need for building in input and output of data into the architecture of a CPU and fill in the blanks.
#1 A computer needs peripherals for the INPUT and OUTPUT of data. 

#2 A computer reads data in and sends data out through 
its I/O ports. 

#3 A port is simply a gateway, like a port used for shipping. 

#4 Every I/O port, a little like how a part would need a shipping controller, needs to 
be managed. 

#5 An I/O controller is the term used to describe the I/O port along with 
the circuits that manage data into and out of the port. It allows you to connect up 
any I/O device to the PC and transfer data in to or out of the computer. 

#6 You wouldn’t want to connect an I/O device directly to a CPU because you would have to 
redesign the CPU every time a new type of device came along. Besides, a new type of 
device might need different voltages and control signals from the CPU, again 
necessitating a CPU redesign. 

The The I/O controller therefore, acts as an _____________________________________


  a second CPU that speeds up performance

  blockage to cause more problems

  interface to overcome these problems.

  input device to allow input in at a greater speed

 10. The von Neumann bottleneck was described by John Backus in his 1977 ACM Turing Award lecture. What causes it?
The shared bus between the program memory and data memory leads to the von Neumann bottleneck

The underlying criticism is that the programming model relies on data being constantly 
transferred back and forth between memory and the processing unit

No matter how fast a given processor can work, in effect it is limited to the 
rate of transfer allowed by the bottleneck. 

  Just #1

  None of the above

  All of the above

  Just #2

 11. One way of addressing the issue of the bottleneck (von neumann architecture) is to:

  Provide a cache between the CPU and the main memory

  Provide the CPU with more electricity to power it

  Provide a thinner bus

  Provide a greater amount of data

 12. Von Neumann architecture refers to the use of two processors.



 13. The number of bits that can be fetched in one go from the IAS (Immediate access store) is known as the

  bit size

  word size

  mit size

  letter size

 14. All the instructions that any particular CPU can use are known as the INSTRUCTION SET



 15. The accumulator is a type of:





 16. Von Neumann processors have separate areas of memory for data and the programs that use them.



 17. Whilst in use the data and instructions in a von neumann architecture computer are stored in RAM (Main Memory) In order for the CPU to fetch an instruction from main memory (RAM), the instruction is temporarily stored in:

  a special bit of cache called the Memory Cache

  a special register called the MDR (Memory Data Register)

  a small portion of ROM on the Hard drive

  the ALU (Arithmetic Logic Unit)

 18. The address of the data or instruction being accessed is temporarily stored in the Memory Address Register.(MAR)



 19. The program counter within the CPU is:

  a register that records or holds the current instruction being executed. It can be incremented

  a program that counts from 1 to a million and repeats this several times

  a counter that keeps record of the clock ticks

  a program that contains instructions

 20. The design of a von Neumann architecture machine is simpler than that of a Harvard architecture machine, which is also a stored-program system but has ...

  the same bus for reading data and instruction fetching

  one dedicated set of address and data buses for reading data from and writing data to memory, and another set of address and data buses for instruction fetching.

  4 billion buses

  multiple processors with several ALUs (Arithmetic Logic Units)