Computer Architecture

Question 1

What is the Stored Program Concept?

Answer 1

Machine code instructions stored in main memory are fetched and executed serially by a processor that performs arithmetic and logical operations

Question 2

What’s the function of the ALU and what does it stand for

Answer 2

The Arithmetic Logic Unit performs arithmetic and logical operations.

Question 3

What are examples of functions the ALU performs?

Answer 3

Performs functions such as:

• Fixed and floating point arithmetic
• Logical operations (AND, OR, XOR)
• Shift operations
• ADD, DIVIDE, SUBTRACT, MULTIPLY

Question 4

Where are the inputs from and the outputs of the ALU ?

Answer 4

Inputs are from the accumulator

Outputs are routed to one of the registers.

Question 5

What is the function of the Control Unit?

Answer 5

• Directs data flow between the cpu and other devices

- fetches program instructions from memory, to decode them and to execute them serially.

Question 6

What is the function of the system Clock?

Answer 6

The clock synchronises all computer operations by sending a signal to each of the computer components on a regular basis.

Question 7

What is a register?

Answer 7

A register is fast temporary storage that exists in the processor or I/O controller.

Question 8

What are the two types of registers?

Answer 8

General purpose and dedicated registers

Question 9

What are General Purpose registers used for?

Answer 9

• Usually named R0-R15
• They are used to hold instructions and data temporarily.
• All arithmetic/logical/shift operations takes place in the general purpose registers

Question 10

What are special purpose/dedicated registers used for, name the 6 main ones?

Answer 10

They are used by the processor to carry out a specific role.

• PC, Program Counter
• ACC, Accumulator
• MAR, Memory Address Register
• MBR, Memory Buffer Register
• CIR, Current register
• SR, Status Register

Question 11

What is Von Neumann Architecture?

Answer 11

Is when both instructions and data are stored in the same memory and share the same buses

Question 12

What is Harvard Architecture?

Answer 12

is when data and instructions are stored in seperate memories and are accessed using different buses

Question 13

When is Von Neumann Architecture mostly used?

Answer 13

• Used for general use computers

- helpful for running a variety of programs simultaneously

Question 14

When is Harvard Architecture mostly used?

Answer 14

Used in embedded systems and situations where the speed of an operation is important

Question 15

Name the internal components of a computer system?

Answer 15

• Processor
• Main memory
• address bus, control bus, data bus
• I/O controllers

Question 16

What is the role of the processor?

Answer 16

To execute program instructions in order to run applications

Question 17

What does the processor contain?

Answer 17

The control unit, the ALU and registers

Question 18

What is a bus?

Answer 18

A set of parallel wires connecting two or more components of a computer

Question 19

What is an i/o controller?

Answer 19

• A device which receives input/output requests from the processor and sends device specific control signals to the device they control
• They manage data flow to and from the device

Question 20

What are the 3 parts that make up a i/o controller

Answer 20

• An interface connecting the controller to the system bus
• A set of data/command/status registers
• An interface connecting the controller to the cable connecting the device to the computer

Question 21

Give an example of an interface

Answer 21

A USB

Question 22

What is an advantage of using Harvard architecture

Answer 22

Can be faster as data and instructions can be fetched in parallel instead of having to compete for the same bus

Question 23

How many general purpose registers does a computer typically have?

Answer 23

16

Question 24

What is the accumulator?

Answer 24

A general purpose register