7.3.2. Execution Phases of Instructions

Try these first

1. 1.

   What are the four phases of the instruction cycle?

   Hint

   Think of the acronym FDES.

2. 2.

   Define a macro instruction.

   Hint

   Consider how it compares to micro instructions.

3. 3.

   What is the purpose of the program counter?

   • To load data into registers
   • To point to the next instruction
   • To execute operations

   Hint

   Think about how instructions are fetched.

4. 4.

   True or False: Micro instructions execute in multiple clock cycles.

   • True
   • False

   Hint

   Remember how micro instructions operate.

5. 5.

   Consider the instruction 'LOAD A, 3030'. Break down this macro instruction into its micro instructions, detailing the fetch, decode, execute, and store phases.

   Hint

   Map each phase to specific micro instructions.

6. 6.

   Discuss a real-world scenario where clock grouping could be applied in processor design. What benefits would this bring?

   Hint

   Consider how parallel execution benefits overall throughput.