A Level Computer Science OCR Practice Exam

What role does the Control Unit play in the functioning of a CPU?

1. It performs arithmetic and logical operations

2. It fetches, decodes, and executes instructions while sending control signals

3. It stores temporary data and control information

4. It contains the memory address of the current instruction

The correct answer is: It fetches, decodes, and executes instructions while sending control signals

The Control Unit is a critical component of the CPU that manages and coordinates all the activities within the processor. The primary function of the Control Unit is to fetch instructions from memory, decode them to understand what actions are required, and then execute those instructions while sending appropriate control signals to other parts of the CPU and computer system. During the fetch-decode-execute cycle, the Control Unit directs the flow of data between the CPU and memory, ensuring that instructions are processed in the correct order and that resources are allocated efficiently for the execution of tasks. By issuing control signals, the Control Unit tells other components, such as the Arithmetic Logic Unit (ALU), when to perform operations, which data to use, and how to manage results. Therefore, the correct understanding of the Control Unit's role reinforces its importance in executing instructions and overall CPU functionality, confirming that it is responsible for both control signals and the orchestrated operation of the processor's tasks.