The control unit is central to the operation of the CPU. Describe the control unit’s role in the execution of machine code statements.

The control unit of the CPU plays a crucial role in the execution of machine code statements. Here's a step-by-step description of its role:

1. Fetch: The control unit begins the process by fetching the machine code instruction from the computer's memory. This is done by sending a signal to the memory with the address of the instruction to be fetched.

2. Decode: Once the instruction is fetched, the control unit decodes it. This involves determining what operation the instruction is supposed to carry out. The control unit has a set of predefined operations that it can perform, and it uses the opcode (operation code) of the instruction to determine which operation to perform.

3. Execute: After the instruction is decoded, the control unit executes it. This involves sending signals to the appropriate parts of the CPU or other hardware components to carry out the operation. For example, if the instruction is to add two numbers, the control unit would send signals to the arithmetic logic unit (ALU) to perform the addition.

4. Store: Once the operation is complete, the control unit stores the result in the appropriate location. This could be a register within the CPU or a location in memory.

5. Repeat: The control unit then moves on to the next instruction in the sequence, repeating the fetch-decode-execute-store cycle.

In summary, the control unit acts as the "brain" of the CPU, coordinating and controlling the execution of machine code instructions.