a. The Soda module:

A FSM processis used to update the present state to the next state when a clocked coin is entered, this process is used to show the description of the transitions of state machines from state to state using the Case statement.

Study the 35-cent soda vending machine VHDL description for this module below then complete part a VHDL programmed to dispense a product in the following manner:

The machine requires the equivalent of 7 nickels made of a combination of Quarters, Dimes and provides possible change.There are 7-coin states labeled sevenN(7 nickels needed), sixN (six more nickels needed), fiveN(five more nickels needed) etc... plus two dispense states, one with change, dispense_C and one without change, dispense_NC. All these states are declared as enumerated TYPE.

The coins can be accepted one at a time by pushing the KEY button.Initially, a green light, ready is on.The first state is labeled seven requiring the equivalent of seven nickels (7 x 5=35) made of a combination of quarters, dimes and nickels.

If a Quarter is entered, two more nickels are needed, so the next state will be twoN(two more nickels needed).

If a Dime is entered, five more nickels are needed, so the next state will be fiveN.

If a Nickel is entered, six more nickels are needed, so the next state will be sixN.

Also, the add_coin output is activated when more change is required into the machine.

If no coin is entered, the next state will be the present state sevenN.The process repeats for all the other states.

Procedure:a. Soda module

This module uses FSM design where one process will be used to update the present state to the next state when a clocked coin is entered, it is used to show the description of the transitions of state machines from state to state using the case statement. See more description above under discussion.Copy and paste the code below then complete it using the discussion above. (note: there are 2 copies for dispense, dispens0 and dispense1)

library IEEE;

use IEEE.STD_LOGIC_1164.ALL;

use IEEE.STD_LOGIC_ARITH.ALL;

use IEEE.STD_LOGIC_UNSIGNED.ALL;

entity soda is port (___,___,____,___,____: ___ ____; --reset,clock,Quarter Q, Dime D, Nickel N

___,___,____,___,____: ___ ____); -- ready, add_coin, change, dispense0,

dispense1

end soda;

architecture behavioral of soda is

Type states is (oneN, twoN, threeN, fourN, fiveN, sixN, sevenN, dispense_NC, dispense_C);

Signal next_state: states; beginprocess (____,_____,____,____,____) --sensitivity list begin

ready <= '0'; --describe default state

dispense0<= '0';

dispense1<= '0';

more_coin<= '0';

change<= '0';

if reset ='0' then next_state <=_______; --on reset always go to sevenN

elsif ____________(clk) then --on rising edge of clock

case next_state is

when sevenN => -- seven Nickels needed

--describe this state below

ready <= '__'; --activate ready

dispense0<= '__'; --no dispense yet

dispense1<= __';

add_coin<= '__'; --no coin detected yet

change<= '__'; --no change yet

--Check for incoming coins

if Q='1' then--check if quarter

next_state<= ____;

elsif D='1' then--check if Dime

next_state<= _____;

elsif N='1' then --check if Nickel

next_state<= ____;

else next_state<= ______; --stay

end if;

when sixN => -- six Nickels needed

--describe this state below

ready <= '__'; --deactivate ready

dispense0<= '__'; --no dispense yet

dispense1<= __';

add_coin<= '__'; --ask for more coins

change<= '__'; --no change yet

--Check for incoming coins

if Q='1' then

--check if quarter

next_state<= ____;

elsif D='1' then--check if Dime

next_state<= _____;

elsif N='1' then --check if Nickel

next_state<= ____;

else next_state<= _____; --stay

end if;

when fiveN => -- five Nickels needed

--describe this state below

ready <= '__'; --deactivate ready

dispense0<= '__'; --no dispense yet

dispense1<= __';add_coin<= '__'; --ask for more coins

change<= '__'; --no change yet

--Check for incoming coins

if Q='1' then--check if quarter

next_state<= ____;

elsif D='1' then--check if Dime

next_state<= _____;

elsif N='1' then --check if Nickel

next_state<= ____;

else next_state<= _____; --stay

end if;

when fourN => --four Nickels needed

--describe this state below

ready <= '__'; --deactivate ready

dispense0<= '__'; --no dispense yet

dispense1<= __';

add_coin<= '__'; --ask for more coins

change<= '__'; --no change yet--Check for incoming coins

if Q='1' then--check if quarter

next_state<= ____;

elsif D='1' then--check if Dime

next_state<= _____;

elsif N='1' then --check if Nickel

next_state<= ____;

else next_state<= ___;--stay

end if;

when threeN => -- three Nickels needed

--describe this state belowready <= '__'; --deactivate

ready dispense0<= '__'; --no dispense yet

dispense1<= __';

add_coin<= '__'; --ask for more coins

change<= '__'; --no change yet--Check for incoming coins

if Q='1' then--check if quarter

next_state<= ____;

elsif D='1' then--check if Dime

next_state<= _____;

elsif N='1' then --check if Nickel

next_state<= ____;

else next_state<= ______; --stay

end if;

when twoN => -- two Nickels needed

--describe this state below

ready <= '__'; --deactivate ready

dispense0<= '__'; --no dispense yet

dispense1<= __';

add_coin<= '__'; --ask for more coins

change<= '__'; --no change yet

--Check for incoming coins

if Q='1' then --check if quarter

next_state<= ____;

elsif D='1' then--check if Dime

next_state<= _____;

elsif N='1' then --check if Nickel

next_state<= ____;

else next_state<= _______;--stay

end if;

when oneN => -- one Nickel needed

--describe this state below

ready <= '__'; --deactivate ready

dispense0<= '__'; --no dispense yet

dispense1<= __';add_coin<= '__'; --ask for more coins

change<= '__'; --no change yet

--Check for incoming coins

if Q='1' then --check if quarter

next_state<= ____;

elsif D='1' then--check if Dime

next_state<= _____;

elsif N='1' then --check if Nickel

next_state<= ____;

else next_state<= ________; --stay

end if;

when dispense_C => --dispense with change

ready<='__';

add_coin<= '__';

change<= '___'; --activate change

dispense0<= '__'; --activate dispense

dispense1<= '__';

next_state<= next_state;

when dispense_NC => --dispense without change

ready<='__';

add_coin<= '__';

change<= '___'; --no change

dispense0<= '__'; --activate dispense

dispense1<= '__';

next_state<= next_state;

end case;

end if;

end process;

end behavioral;