fetch execute cycle

Question 1

What are the 4 main components of a cpu

Answer 1

arithmetic logic unit (alu), control unit (cu), clock and bus

Question 2

What does a control unit do?

Answer 2

• controls the execution of instructions in the correct sequence
• it decodes instructions
• it regulates and controls processor timing using regular pulses from the system clock
• it sends and receives control signals to and from other devices within the computer

Question 3

What does the clock do in the CPU

Answer 3

The system clock controls processor timing, switching between zero and one at rates exceeding several million times per second. It synchronizes all CPU operations.

The clock frequency is the number of clock cycles which occur each second

Question 4

What are the 3 main things that the ALU does?

Answer 4

• logic operations (e.g AND, OR , NOT)
• shift operations
• arithmetic operations (addition, subtraction)

Question 5

What are the 3 buses

Answer 5

address bus ,control bus , data bus

Question 6

What happens in the fetch part of the fetch execute decode cycle?

Answer 6

-The address of the instruction (that is going to be executed) is fetched from the register

Question 7

What happens in the decode part of the fetch execute decode cycle?

Answer 7

The control unit decodes the instruction to see what has to be done next.

Question 8

What happens in the execute part of the fetch execute decode cycle?

Answer 8

The processor checks the program counter to see which instruction to run next.

The program counter gives an address value in the memory of where the next instruction is.

The processor fetches the instruction value from this memory location.

Question 9

What factors can affect a cpu’s performance

Answer 9

clock speed , amount of cache and amount of processor cores

Question 10

What is the fetch decode execute cycle also known as

Answer 10

The instruction cycle