VLSI Design and Technology Projects

Draw state diagram, write VHDL code, write test bench code and implement using Spartan-III kit.

1.    VCR Controller: 

Implement a VCR controller as a Moore FSM.

The user controls the motion as follows:

            Pressing the Play button causes the tape to play.
            Pressing the FF button causes the tape to advance:
                        Without playing, if stopped.
                        Scanning, if in play mode.
            Pressing the Stop button causes the tape to stop.
            Pressing the Rew button causes the tape to rewind:
                        Without playing, if stopped.
                        Scanning, if in play mode.

            Note: I haven’t specified all transitions possible...

Outputs: Forward, Reverse, Fast, HeadReading

2.    Combinational Lock 1:

A 3-bit serial combination lock is used to allow entry into a locked room.  The lock has  RESET button, an ENTER button, and a two-position switch to represent the key being entered.  When the signal UNLOCK is asserted, an electromechanical relay is released, allowing the door to open.  The unlock process begins when the operator presses RESET.  He or she then sets the input switch, followed by pressing the ENTER button.  This is repeated for the second and third key digits.  An ERROR light should be illuminated if, after entering the three binary digits, the operator has not matched the key.  The process can be started again by hitting reset again.  

3.    Air Lock Controller

Implement an airlock controller as a Moore FSM.

The airlock has two doors – insideDoor and outsideDoor. These are controlled by the signals insideDoorOpen and outsideDoorOpen.

There are two buttons – insideRequest and outsideRequest.

The airlock pressure is controlled by a single signal – pressurize. The pressurize/depressurize process takes 10 seconds.

A ten second timer is available. It has input StartTimer and output TimeUp.

The reset state is:

Both doors closed. Airlock pressurized.

When a request button is pressed, the following must happen:

1. The chamber is either pressurized or depressurized depending on which button was pressed.
2. The appropriate door is opened for ten seconds and then closed.
3. The chamber’s pressure is inverted.
4. The opposite door is opened for ten seconds and then closed.

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          4. Combinational Lock 2:

Design another combo lock controller as a Mealy FSM...

The combination is A-A-B-A-B-A.  If this is entered, output “open”.

From any state, three B’s in a row will reset the lock to it’s beginning state.

Whenever an out-of-sequence A occurs, an output “bell” is asserted to raise an alarm.

Once the lock is open, pressing either A or B will reset it to the beginning state.

      5 Washing Machine Controller:

Design a washing machine controller as a Moore FSM...

Operation: When start is pressed, goes through wash, spin, rinse, spin cycles. If “double rinse” is selected, an extra rinse and spin cycle is added.

Details: Must fill the tub with water before washing or rinsing – output the signal “filltub” to do this. A timer is provided that gives the appropriate amount of time for a wash, rinse, or spin cycle.

Outputs:

Filltub – turns on water to tub.
Agitate – turns on agitator for wash and rinse
Spin – turns on spinner
StartTimer – starts the wash/rinse/spin timer – the timer’s start input is rising-edge triggered

Inputs:
Start – starts a wash
Tubfull – true when tub is full of water
Double – true if user wants a double rinse
TimeUp – true when time for wash/rinse/spin is done

6.    

       6. Tennis Scorer:

Design a Moore finite state machine that keeps track of score in a tennis game.  Tennis is scored as follows:

•         There are two players, A and B. 

•         Scoring starts at zero, which is known in tennis lingo as love.

•         As a player wins games, his/her score advances as follows:

Love à 15 à 30 à 40 à Game

•         The first one to achieve “Game” wins.

•         The score 40-40 is known as deuce.  If the score is deuce, then the first player to win two points in a row wins the game.

Your finite state machine will have synchronous inputs A, which is true whenever A wins a point, and B, which is true whenever B wins a point, and a reset input.   

The outputs should be “A wins” and “B wins”, asserted at the appropriate times.  Each state should be labeled with the current score of player A and player B (i.e. 15-Love or 40-15).

7.    

       7. Traffic Light Controller:

n  A busy highway is intersected by a little used farmroad

n  Detectors C sense the presence of cars waiting on the farmroad

q  with no car on farmroad, light remain green in highway direction

q  if vehicle on farmroad, highway lights go from Green to Yellow to Red, allowing the farmroad lights to become green

q  these stay green only as long as a farmroad car is detected but never longer than a set interval

q  when these are met, farm lights transition from Green to Yellow to Red, allowing highway to return to green

q  even if farmroad vehicles are waiting, highway gets at least a set interval as green

n  Assume you have an interval timer that generates:

q  a short time pulse (TS) and

q  a long time pulse (TL),

q  in response to a set (ST) signal.

q  TS is to be used for timing yellow lights and TL for green lights

Prof. Dr. Sunita P. Ugale