You are to design the control for an automatic candy vending machine. The candy bars inside the machine cost 25 cents, and the machine accepts nickels, dimes, and quarters only. The inputs to the control are a set of three signals that indicate what kind of coin has been deposited, as well as a reset signal. The control should generate an output signal that causes the candy to be delivered whenever the amount of money received is 25 cents or more no change is given . Once the candy has been delivered, some external circuitry will generate a reset signal to put the control back into its initial state. Required:
a. Identify your inputs and outputs, and draw the ASM chart that implements this finite state machine.
b. Assuming no change given, draw a state diagram that implements the finite state machine.
c. Implement the finite state machine using D, T and JK flip-flops. You may use gray code state assignment.
d. Verify the D flip-flop implementation in (b).
e. Write Verilog HDL models for the machine based on the state diagram in (a) and the D flip-flop sequential circuit that you implement in (b).
f. Modify your control design such that the vending machine may give change if more than 25 cents is deposited. You do not have to implement your design. State diagram is sufficient.