19.4.2. Design Objective for Controllers

Try these first

1. 1.

   What does FSM stand for?

   Hint

   Think of a machine that has several states.

2. 2.

   What role does the Program Counter play?

   Hint

   Where does the CPU look for the next command?

3. 3.

   What does the MFC signal indicate?

   • Memory function pending
   • Memory function complete
   • Memory function failed

   Hint

   Consider when the CPU can proceed.

4. 4.

   True or False: Control signals are only internal to the CPU.

   • True
   • False

   Hint

   Think about where signals come from.

5. 5.

   Design an FSM for a simple arithmetic instruction. Outline state transitions and control signals.

   Hint

   Use examples from our discussion about `ADD` instructions.

6. 6.

   Evaluate the trade-offs between dedicated FSMs for each instruction versus a merged FSM architecture.

   Hint

   Consider performance versus complexity.