20.5.2. Instruction Flow

Try these first

1. 1.

   What is a microprogrammed control unit?

   Hint

   Think about how instructions impact signal production.

2. 2.

   What does the microprogram memory store?

   Hint

   Consider what relates to microinstructions.

3. 3.

   What is a microinstruction?

   • A high-level instruction
   • A low-level instruction
   • A control signal

   Hint

   Remember the differences in instruction levels.

4. 4.

   True or False: Hardwired control units are more flexible than microprogrammed control units.

   • True
   • False

   Hint

   Think about how each unit handles instructions.

5. 5.

   Design a microprogrammed control unit for a simple processor executing ADD, SUBTRACT, and JUMP operations. Outline the microinstructions and necessary control signals.

   Hint

   Think about how the flow of information should be structured and recorded.

6. 6.

   Explain how transitioning from a hardwired control unit to a microprogrammed control unit could impact performance and flexibility in CPU design.

   Hint

   Consider the trade-offs of flexibility versus speed.