12.2.7. Execution of Instructions

Try these first

1. 1.

   What is the primary purpose of control signals?

   Hint

   Think about how data flows in a processor.

2. 2.

   List the three main phases of instruction execution.

   Hint

   Consider what happens step-by-step when a program runs.

3. 3.

   What is the first step in the instruction execution process?

   • Decode
   • Fetch
   • Execute

   Hint

   Think about the order in which instructions are processed.

4. 4.

   True or False: The ALU is primarily involved during the fetch phase.

   • True
   • False

   Hint

   Recall the role of the ALU in the instruction cycle.

5. 5.

   Consider a specific instruction, LOAD R1, M. Describe in detail the sequence of control signals generated during each phase of the instruction execution.

   Hint

   Break down each phase into distinct actions performed by the registers and ALU.

6. 6.

   How do control signals differ between an arithmetic instruction and a memory instruction during execution?

   Hint

   Think about how the instructions determine where data comes from and where it goes!