HARDWARE DESIGN PROBLEM:

Design a MEALY machine control circuit of a MICROWAVE OVEN with the following rules:

• The microwave has a door, a light, a power-tube, a cook button, a timer, a beeper and a display.
• When the oven is not in use and the door is closed, the light and the power-tube are turned off and the display is blank.
• When the door is open, the light stays on.
• If the button is pushed when the door is closed and the oven is not operating, then the oven is activated for one minute. When the oven is activated, the light and the power-tube are turned on.
• If the button is pushed when the oven is operating, one minute is added to the timer.
• When the oven is operating, the display shows the number of seconds of cooking time remaining.
• If the door is opened when the oven is operating, the power-tube is turned off.
• When the cooking time is completed, the power-tube and light are turned off, and the beeper goes on (alarm sound) for 5 seconds.
• Pushing the cook button when the door is open has no effect.
• Cooking is only permitted when the door is closed and the button is pressed. Minimum cooking time is 1 minute per 1 press of the button.

Q4: Draw the state transition diagram (finite state machine diagram, no flow chart) showing all states and transitions based on inputs. Write the name of the input when it is true only.

Q5: Provide the truth table showing Present State variables, inputs, NS variables and outputs

Q6: Extract the Boolean expressions for all the state variables and outputs?

Q7: Use a ROM chip to implement the control circuit: What appropriate ROM memory can be used to for the implementation of this controller? Indicate the size of the ROM, the number of address lines and the number of data lines. Draw the ROM memory and label inputs and output signals as needed. Make sure to include all state variables and any required external logic.