31.3.1. Control Unit Summary

Try these first

1. 1.

   What does the MAR stand for?

   Hint

   Think about what register holds the address information.

2. 2.

   What does the MDR do?

   Hint

   Remember its role when discussing memory operations.

3. 3.

   What does the MAR hold?

   • Memory Address
   • Data Value
   • Control Signal

   Hint

   Think about the role of the address in accessing memory.

4. 4.

   True or False: The MDR is used to store control signals.

   • True
   • False

   Hint

   Remember what tasks the MDR is assigned.

5. 5.

   Design a CPU model that effectively uses both MAR and MDR and illustrate how an instruction is executed step-by-step in both a single and three-bus architecture.

   Hint

   Focus on how the instruction moves through the system.

6. 6.

   Analyze the efficiency of using control signals in a three-bus architecture compared to a single-bus architecture when executing a large instruction set.

   Hint

   More signals mean greater complexity; contrast with speed of execution.