Procedure

Circuit Diagram and Simulation of a Finite State Machine

Here we have design a state machine for a simple combinational lock where the passcode is 4 bit binary number 1001. The state diagram is as follows.

The corresponding circuit diagram and simulation has been shown below with the help of D Flip Flop and 4 bit AND gate.

• The D Flip Flop is designed as below:

  • Design Latch circuit and make a component say ‘Latch’.
  - Using the latch, design a D-FF and make a component as shown below.

• 4 input AND gate is designed as below.

  

Circuit and Simulation of the combinational lock is as below

186: Input, 192: Output

State 1: Data: 1111 State: Locked

State 2: Data: 0111 State: Locked

State 3: Data: 0011 State: Locked

State 4: Data: 1001 State: Un-Locked

Step 5: Data: 0100 State: Locked

Manual

• Refer the simulator manual on how to design the circuit
  • Manual --> Click Here