#1 - Contemporary Processors

1. Which of these statements about the ALU is not true?

• A. ALU stands for Arithmetic Logic Unit
• B. It carries out logical evaluation, such as evaluating 'False OR True' to the result 'True'
• C. Instructions are decoded here
• D. Arithmetic operations carried out in the ALU include division and multiplication

2. What does the Control Unit inside the CPU do?

• A. Carries out arithmetic calculations and logical AND/OR/NOT operations
• B. Holds the intermediate results of computations carried out by the ALU
• C. Stores the address of the next instruction that is to be fetched from memory
• D. Sends control signals along the control bus to coordinate other CPU components

3. At what stage in the fetch-decode-execute cycle is the instruction in the CIR sent to the control unit to be separated into its operator and operand(s)?

• A. Fetch
• B. Decode
• C. Execute
• D. Neither fetch, decode nor execute

4. State the role of the Program Counter (PC) during the fetch phase of the fetch-execute cycle.

• A. It holds the memory address at which the next instruction can be found
• B. It stores data that has been fetched from memory
• C. It stores an instruction that has been fetched from memory
• D. It coordinates all of the other components of the CPU to keep them synchronised

5. Name the register that holds the results of the ALU's computations.

• A. Memory Data/Buffer Register
• B. Accumulator
• C. Program Counter
• D. Current Instruction Register

6. During the fetch phase, where do the Program Counter's contents get copied to?

• A. Memory Address Register
• B. Memory Data Register
• C. Current Instruction Register
• D. Accumulator

7. Which of these statements about the CIR is not true?

• A. CIR stands for Current Instruction Register
• B. The CIR sends out signals that coordinate the other CPU registers
• C. Instructions are copied from the CIR to the Control Unit to be decoded and executed
• D. An instruction enters the CIR via the MDR during the fetch phase of the fetch-execute cycle

8. Which of these accurately describes how the MAR is used?

• A. It stores memory addresses, data values and instructions
• B. It stores data or instructions
• C. It stores only data values
• D. It stores only memory addresses

9. Which of these is a stage of the decode phase?

• A. The instruction that is held in a specific memory location is brought from the memory unit into the CPU along the data bus
• B. The ALU is used to manipulate the bits
• C. The instruction is separated into an opcode/operator/operation and its associated operand(s)
• D. The contents of the PC are copied into the MAR

10. Which of these is a characteristic of the control bus?

• A. It carries control signals that affect the operation of other components of the CPU including the ALU
• B. It is used within the control unit only
• C. It allows signals to pass between the address bus and data bus
• D. It carries data from the secondary storage to the main memory unit