Deliverables You are to design TWO finite-state synchronous machines, one being a Moore design and the other being a Mealy design.

Deliverables

You are to design TWO finite-state synchronous machines, one being a Moore design and the

other being a Mealy design. Depending on the application you have to decide whether you

have to synchronize the outputs of the Mealy machine or not. You can use either D flip flops

or J-K flip flops for your designs. Mixing different types of flip flops with different trigger

edge sensitivity is possible but not recommended. Note that two designs which differ by only

the type of flip flop (e.g., J-K vs. D) or number of states (i.e., changing the type of FF or

inserting more unnecessary states) is not considered conceptually different.

First, you will need to implement BOTH designs using Logisim and include these simulations

into your lab report template. Second, you will need to build ONE design using the TTL parts

you used in earlier lab work and report your findings on the lab report template. You can use

any part that you have available, J-K or D flip flops. The 4-bit D Register (74LS175 with clock

and reset already wired together for the four D flip flops) that you have not used before might

come in handy for the design project, in case you have it

Dishwasher Controller

The Clean Dish Company (CDC) is interested in reducing the risk of personal injury to their users,

especially the kids, while operating their Dishwasher at their homes. When a user opens the

machine's door while in operation, the machine should stop. Otherwise, the user might get

injured. Hence, in addition to the on/off power switch that controls the machine, there is another

sensor (door sensor) that is activated when the door is opened to stop the machine.

They have asked you to design a controller that does the following: If the user powers on the

machine, the controller should start operating the machine. If the user needs to open the door for

some reason, then they need to power the machine off first. If the user opens the door (i.e. if the

door sensor is activated) while the machine is on, then the controller should stop the machine

until the door is closed back again (door sensor goes back off). Opening the door while the

machine is on is considered a "violation". Since the company needs to account for kids at home

who might repeat this violation, your controller should shut off permanently if this violation was

repeated for the second time, even if these two violations are NOT in a row. At that point, even if

the user closes the door, the machine should not turn on again unless the parent resets the

machine through a reset switch that they hid from their kids.

Note that there are two inputs to your controller: the on/off power switch S (S=1 means the

user is requesting to turn the machine on) and the door sensor D (D=1 indicates that the door

is open). Your controller has one output P that controls the power feeding the washing

machine's motor (P=1 indicates that the power is connected and the machine is operating).

All information to complete this design may not be specified. Write down and

report any assumptions that you make in your design.

Assumptions

1. The benefit of the assumptions task is for you to tell the grader: "These are

the limitations of the machine that I am going to build".

2. Assumptions list is like a "Users' Manual" of how to operate the machine that you

built. It should be given to the user to let them know the DO's and DONT's.

3. Mention anything you want such that it does not make the problem trivial.

For example do not say: "I'm assuming that the user will power off the

machine before opening the door". This means that there will be no

"violations". This over simplifies the problem which is not accepted.

4. A good designing engineer should take all possible input combinations into

consideration rather than assuming some of them will not happen. Do not assume

that an input combination (for example the input 01) will not happen at any state. All

input combinations need to be taken into consideration while writing your state

diagram. However, if there is some input combination that is meaningless at a

particular state, then mention this in your assumptions and justify it.

5. While filling in the assumptions section, always remember that it is up to

you to assume what you want as long as it will make common sense.

6. We don't want a large list of assumptions. 2-3 assumptions are enough.

7. You don't have to list the assumptions before finishing your design. You might need to

modify it while designing your machine. That is the nature of any design process.

8. Your assumptions for Design 2 could be the same as those for Design 1, but don't have to.

9. Answers to (some) the following questions might be good

candidates to be your assumptions:

2

1. Does your machine need/use an asynchronous reset?

2. What should the state of the system be before the user starts the

machine? If the previous use of the dishwasher (that happened a

couple of days ago) experienced a single violation only, does the user

need to do anything before starting new washing cycle?

3. What if the preceding use has put the machine in the "permanent shut

down" state? What should the user do before using it for a new cycle?

Check List

1. First step is to define the inputs and outputs of your design, as well as the

values that each input and output might take.

2. Make sure you have included your assumptions for your project.

3. Make sure your state diagram is complete: no missing arrows/states/inputs/outputs.

4. Make sure your state diagram is readable: Which value mentioned on the

arrow corresponds to which input.

5. Make sure to use a synchronization flip flop at the output of the Mealy machine.

We will not penalize if you don't have it, but if you test your circuit without it, you

need to know how to verify your circuit is working. It needs some experience.

6. In task 4-5, the clocks of the flip flops need to be connected to a "Logic

Switch". Some students connect them to a manual switch. If you have a

manual switch, don't use it to feed the clock.

1. If you are using a trainer board, they Logic switch are clearly labeled on

them to be distinguished from the Data Switches (aka manual switches).

2. If you are using an Analog Discovery Kit (ADK), then any DIO is

considered a Logic Switch.

7. If your system has more than one input, which one is what (on your state diagram)? (Also

don't forget to name your input switches in your Logisim files. Graders might consider your

Logisim files not working if you did not label your input switches: CLOCK, Reset....etc.).

8. When filling in the column of the output in the Moore transition table, you need to look at

the present state not at the next state because in a Moore state transition table, the output

depends on the present state and not the next state. This is a fact that applies to the Moore

design and not to the Mealy design. Thus, if you found your output changes with the change

in the input when you simulate your Moore circuit, then you have missed this fact.

9. Any state diagram should be complete: Each state has to have 2n arrows

coming out of it where n is the number of inputs to the system. This is the

case for both the Mealy and the Moore machine.

10.Don't forget to connect the PRE' and the CLR' of your chips to the Vcc while

you build your hardware portion of this lab.

11. Do not build the FFs from scratch when simulating your design on

Logisim. Use the FFs built-in already in Logisim. They are found under the

"Memory" folder in the Logisim software.