7.3. Micro Instructions and Instruction Execution

Try these first

1. 1.

   What is a macro instruction?

   Hint

   Think about complexity and clock cycles.

2. 2.

   Can you name the four phases of instruction execution?

   Hint

   Remember the sequence FDES.

3. 3.

   What are micro instructions?

   • A. Complex instructions
   • B. Simple instructions executed in one clock cycle
   • C. Instructions requiring multiple cycles

   Hint

   Consider what 'micro' implies about complexity.

4. 4.

   True or False: All macro instructions can be executed in a single clock cycle.

   • True
   • False

   Hint

   Reflect on the definition of macro instructions.

5. 5.

   Given a macro instruction that involves several arithmetic and logical operations, break down the instruction into its respective micro instructions and identify how many clock cycles would be required to execute each part.

   Hint

   Consider how many steps are involved in each part of your macro instruction.

6. 6.

   Design a simple instruction set and for a specific instruction, identify potential micro instructions. Discuss how clock grouping could optimize the instruction's execution.

   Hint

   Look at the operations involved and see which ones can run in parallel.