3.1 Computer Structure

Question 1

What is the role of the CPU in a computer?

Answer 1

The CPU processes instructions and data that are input into the computer so the result can be output.

Question 2

What is a microprocessor?

Answer 2

A microprocessor is a type of integrated circuit on a single chip.

Question 3

What are the components of a CPU in a Von Neumann architecture?

Answer 3

• Arithmetic and Logic Unit (ALU)
• Control Unit (CU)
• Registers
• System Clock
• System Buses
• Memory

Question 4

What is the function of the Arithmetic and Logic Unit (ALU)?

Answer 4

• The ALU allows arithmetic operations (e.g., +, −) and logic operations (e.g., AND, OR) to be carried out.
• It also performs multiplication and division using shifting operators.

Question 5

What is the function of the Control Unit (CU)?

Answer 5

• Reads instructions from memory.
• Generates signals during the Fetch-Decode-Execute cycle to control computer components.
• Synchronizes data flow and program instructions.

Question 6

What are registers, and what do they store?

Answer 6

Registers are high-speed areas of memory within the CPU used to store:

• Small amounts of data.
• The address of the next instruction.
• The current instruction is being decoded.

Question 7

Name the types of registers in a CPU.

Answer 7

• Current Instruction Register (CIR)
• Accumulator (ACC)
• Memory Address Register (MAR)
• Memory Data/Buffer Register (MDR)
• Program Counter (PC)

Question 8

What is the purpose of the System Clock in a CPU?

Answer 8

• The system clock produces timing signals to synchronize functions.
• Changing the clock speed can improve performance but risks overclocking, which may cause overheating and crash the computer.

Question 9

What are system buses, and how do they function?

Answer 9

System buses transfer data and control signals in the computer.

Types:

• Address bus (unidirectional) - Carries addresses
• Data bus (bidirectional) - Transfers data
• Control bus (bidirectional) - Carries control signals

Question 10

What determines the word size and performance of a computer?

Answer 10

The width of the data bus and address bus.

Question 11

What is the function of RAM and ROM in primary memory?

Answer 11

• RAM holds data, programs, and the operating system in use.
• ROM contains start-up routines and cannot be altered.

Question 12

Describe the process of the Fetch-Decode-Execute cycle.

Answer 12

• PC contains the address of the next instruction.
• The address is copied to the MAR via the address bus.
• Instruction is copied to the MDR.
• Instruction in the MDR is moved to the CIR.
• PC is incremented by 1.
• Instruction is decoded and executed.

Question 13

How does the clock affect CPU performance?

Answer 13

A faster clock speed increases processing speed but may risk overheating due to overclocking.

Question 14

How do caches improve CPU performance?

Answer 14

• Caches store frequently used instructions and data, speeding up processing.
• Larger cache memory improves performance.

Question 15

What is a core, and how does it improve CPU performance?

Answer 15

• A core contains an ALU, CU, and registers.
• Multiple cores (e.g., quad-core) allow parallel processing, improving CPU performance.

Question 16

What is an instruction set in a CPU?

Answer 16

A list of all commands a CPU can process, written in machine code.

Question 17

What is an embedded system, and where is it used?

Answer 17

• An embedded system performs a dedicated function (e.g., in domestic appliances, cars, vending machines).
• It differs from general-purpose computers (e.g., Personal computers (PCs), and laptops).