GCSE Knowledge Check CPU Components

What is the primary function of the CPU?

• Store data in memory

• Execute input/output operations

• Process instructions

• Control peripheral devices

Answer explanation

The primary function of the CPU is to process instructions. It interprets and executes commands from programs, making it the central component in computing tasks.

Which component of the CPU is responsible for performing arithmetic and logical operations?

• Control Unit

• Memory Address Register

• Arithmetic Logic Unit (ALU)

• Program Counter

Answer explanation

The Arithmetic Logic Unit (ALU) is the component of the CPU that performs all arithmetic and logical operations, making it essential for executing calculations and decision-making processes in computing.

What is the main idea behind the stored program concept?

• Programs are stored on punched tape

• Instructions and data are stored in the same memory

• Programs are stored in external hard drives

• Programs must be input manually for each execution

Answer explanation

The stored program concept allows both instructions and data to reside in the same memory, enabling programs to be executed directly from memory without manual input for each run, unlike the other options.

Which of the following is NOT a function of the Control Unit (CU)?

• Decode instructions

• Manage the execution of instructions

• Carry out arithmetic and logical operations

• Send signals to memory

Answer explanation

The Control Unit (CU) is responsible for decoding instructions, managing their execution, and sending signals to memory. It does not perform arithmetic and logical operations, which are handled by the Arithmetic Logic Unit (ALU).

In the Von Neumann architecture, what is stored in the same memory?

• Only data

• Only programs

• Both data and instructions

• Only instructions

Answer explanation

In the Von Neumann architecture, both data and instructions are stored in the same memory. This design allows the CPU to fetch instructions and data from the same memory space, enabling efficient processing.

The Memory Address Register (MAR) holds:

• The current instruction being executed

• The address of the instruction to be fetched

• The results of arithmetic operations

• The data to be processed

Answer explanation

The Memory Address Register (MAR) specifically holds the address of the instruction to be fetched from memory, making it crucial for the instruction cycle in a CPU.

The System Bus in a CPU includes all of the following except:

• Address Bus

• Data Bus

• Arithmetic Bus

• Control Bus

Answer explanation

The System Bus in a CPU consists of the Address Bus, Data Bus, and Control Bus. There is no Arithmetic Bus; arithmetic operations are handled by the CPU's ALU, not a separate bus.

Which bus is responsible for transmitting commands from the CPU to other components?

• Address Bus

• Data Bus

• Control Bus

• Memory Bus

Answer explanation

The Control Bus is responsible for transmitting commands from the CPU to other components, coordinating the operations of the computer. It carries control signals that manage the activities of the system.

In the CPU, which bus is bi-directional and responsible for carrying instructions and data?

• Address Bus

• Control Bus

• Data Bus

• Memory Bus

Answer explanation

The Data Bus is bi-directional, allowing it to carry both instructions and data between the CPU and other components. In contrast, the Address Bus is unidirectional, and the Control Bus carries control signals.

What is the role of the Program Counter (PC) in a CPU?

• Store the results of operations

• Hold the address of the next instruction to be executed

• Manage data flow between CPU and memory

• Control the speed of the CPU

Answer explanation

The Program Counter (PC) holds the address of the next instruction to be executed in the CPU. This allows the CPU to fetch and execute instructions in the correct sequence, making it essential for program execution.