3.1 - Computer Architecture

Question 1

What is the role of a CPU in a computer? [2]

Answer 1

• it executes or processes instructions and
  data in a computer application

Question 2

What is meant by a microprocessor? [1]

Answer 2

• a type of integrated circuit on a single chip

Question 3

What is a processor? [2]

Answer 3

• a component/ unit that processes instructions and data that are input into the computer
• so that the results can be output

Question 4

What are fixed program computers? [2]

Answer 4

• very specific function
• they can’t be reprogrammed

Question 5

What are stored program computers? [2]

Answer 5

• these can be programmed to carry out many different tasks
• applications are stored on them

Question 6

What are the characteristics of Von Neumann Architecture? [5]

Answer 6

• must have a processor
• processor must talk directly to the RAM
• RAM contains stored program
• stored program comprises of instructions and data
• each instruction is executed line by line

Question 7

What are the 3 main components of a CPU? [3]

Answer 7

• control unit
• memory unit
• arithmetic and logical unit

Question 8

What is the control unit? [2]

Answer 8

• directs flow between CPU and other devices
• sends control signals to synchronize the execution of instruction and movement of data

Question 9

What is the Arithmetic and Logical Unit (ALU)? [2]

Answer 9

• carries out arithmetic functions like +-/x
• carries out logical operations like AND/OR/XOR of binary numbers

Question 10

What is the memory unit? [2]

Answer 10

• consists of registers that are small memory units
• used for storing intermediate results

Question 11

What are the different registers that are in a CPU? [5]

Answer 11

• program counter
• accumulator
• memory address register
• memory data register
• current instruction register

Question 12

How is the movement of instructions and data done? [1]

Answer 12

by using system buses

Question 13

What is the Address Bus and its direction? [2]

Answer 13

• carries memory address from CPU to RAM
• unidirectional

Question 13

What is the Data Bus and its direction? [2]

Answer 13

• carries data/instructions from RAM to CPU and CPU to RAM
• bidirectional

Question 14

What is the Control Bus and its direction? [3]

Answer 14

• sends control and timing signals to other components
• also receives signal from them
• bidirectional

Question 15

What does the CIR do? [1]

Answer 15

• stores the current instruction being decoded and executed

Question 16

What does the MAR do? [1]

Answer 16

• stores the address of the memory location currently being read to or written to

Question 17

What does the ACC do? [1]

Answer 17

• stores the data of the calculations of the ALU temporarily

Question 18

What does the MDR do? [1]

Answer 18

• stores data that is being transferred to or from the memory

Question 19

What does the PC do? [1]

Answer 19

• stores the address of where the next instruction can be found

Question 20

What is Fetch? [1]

Answer 20

loading from the RAM

Question 21

What is Decode? [1]

Answer 21

converting into CPU language

Question 22

What is Execute? [1]

Answer 22

running the instruction

Question 23

What are factors that affect the performance of the CPU? [4]

Answer 23

• clock cycle
• width of the buses
• cache memory
• CPU cores

Question 24

What is an embedded system? [2]

Answer 24

comination of hardware and software which is designed to carry out a specific set of functions.

Question 25

What are advantages of embedded systems? [2]

Answer 25

- small in size, so easy to fit into devices - consumes very little power

Question 26

What are disadvantages of embedded systems? [2]

Answer 26

- any device that can be accessed over the internet is open to hackers - troubleshooting faults in the device become a specialist task

Question 27

Where are embedded systems used? [3]

Answer 27

- vending machines - security systems - cars