Q$2.$

A sequential logic system is required to control a vending machine. The machine dispenses product when a total of $\backslash (0\mathrm{.}80\backslash )$ has been inputted but it can only accept $50$c and $20$c coins. When a $50$c enters the machine, the system creates a $1$ input signal while a $20$c coin creates a $0$ input signal. The machine does not dispense any change, it should simply activate the output once $\backslash (0\mathrm{.}80\backslash )$ or more has been inputted. In future operation, no excess from previous totals is considered.

Using D Flip$-$Flops, design a Moore machine to realise the system described, clearly showing the state map, transition table, excitation maps and circuit schematic.