24.4.2. ALU Operation Handling

Try these first

1. 1.

   What is a macro instruction?

   Hint

   Think about what type of instruction gives direction to the CPU.

2. 2.

   Define microinstruction.

   Hint

   What level of command is directly executed by the control unit?

3. 3.

   What is the key difference between macro instructions and microinstructions?

   • Macro instructions are lower-level
   • Microinstructions are higher-level
   • Macro instructions often consist of multiple microinstructions

   Hint

   Think about the sizes of the instruction types.

4. 4.

   Branching in microprogramming is used for conditional executions.

   • True
   • False

   Hint

   Relate this to how execution can change depending on the situation.

5. 5.

   Design a microprogram for a simple ALU operation involving addition or subtraction. Optimize the program by sharing common microinstructions.

   Hint

   Identify what steps both operations share and where they differ.

6. 6.

   Given a set of macro instructions, determine the necessary branching paths needed for their execution. Create a flowchart to visualize these paths.

   Hint

   Map out the decision points based on instruction types.