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-- 
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library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
use IEEE.STD_LOGIC_UNSIGNED.ALL;
use IEEE.NUMERIC_STD.ALL;

entity VendingMachine is
    Port ( clk : in  STD_LOGIC;
           LED1 : out  STD_LOGIC;
           LED2 : out  STD_LOGIC;
           Coin : in  STD_LOGIC;
           Cancel : in  STD_LOGIC;
           Prod1 : in  STD_LOGIC);
end VendingMachine;

architecture Behavioral of VendingMachine is
  signal cntr: integer;
  signal CLK1sn: STD_LOGIC;
  type state is (Idle,A,B,C,E);
  signal prev_state: state :=Idle;
  signal next_state: state :=Idle;
  signal LED1x: STD_LOGIC :='0';
  signal LED2x: STD_LOGIC :='0';
begin
  CLKDIV:process(clk,cntr,CLK1sn) is begin
    if(rising_edge(clk)) then
      if(cntr=25000000) then cntr <= 0; CLK1sn<=not(CLK1sn);
      else cntr<=cntr+1; end if;
    end if;
  end process;
  
  process(prev_state,Coin,Prod1,Cancel,LED1x,LED2x) is begin
    case prev_state is
      when Idle =>
           if(Coin='1') then next_state <= A; LED1x <='1'; LED2x<='0'; 
           else next_state <= prev_state; LED1x <='0'; LED2x<='0'; end if;
      when A => 
           if(Cancel='1') then next_state <= C; LED1x <='0'; LED2x<='0';
           elsif(Prod1='1') then next_state <= B; LED1x <='0'; LED2x<='1';
           else next_state <= A; LED1x <='1'; LED2x<='0'; end if;
      when B => next_state <= E; LED1x <='1'; LED2x<='0';
      when E => next_state <= Idle; LED1x <='0'; LED2x<='0';
      when C => next_state <= Idle; LED1x <='0'; LED2x<='0';
      when others => next_state <= prev_state; LED1x <= '0'; LED2x <= '0';
     end case;
  end process;

  process(CLK1sn,next_state,LED1x,LED2x) is begin
    if(RISING_EDGE(CLK1sn)) then
      prev_state <= next_state;
      LED1 <= LED1x;
      LED2 <= LED2x;
    end if;
  end process;
end Behavioral;