unused inputs.

[Faitie]

hi all,

its my first post on this forum so if this is posted in the wrong section plz let me know. Now to ask my question.
I created this piece of code that is supposed to be a digital dice. I can make it work with 1 7-seg but not with 2.
I think i have found the correct way to program it, when i try and build he dousnt add 2 inputs(S1 and S2). I get a warning that they are unused. I'll post the code below so u guys could help me out a bit.

library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
use IEEE.STD_LOGIC_ARITH.ALL;
use IEEE.STD_LOGIC_UNSIGNED.ALL;

---- Uncomment the following library declaration if instantiating
---- any Xilinx primitives in this code.
--library UNISIM;
--use UNISIM.VComponents.all;

entity dobbelsteen is
port(	clock	:	in std_logic;
		S1		:	in std_logic;
		S2		:  in std_logic;
		aan 	:  in std_logic;
		enable:	out std_logic_vector(3 downto 0);
		leds 	:	out std_logic_vector(1 to 7)
	 );
end dobbelsteen;

architecture Behavioral of dobbelsteen is

signal teller : std_logic_vector(3 downto 0):="0001";
signal clk : std_logic;
signal dummy : std_logic_vector(22 downto 0);
signal aan2 : std_logic;

begin
process(clk)
begin
if clock'event and clock ='1' then
	dummy <= dummy+1;
end if;
end process;
	clk <= dummy(22);
	
process (clk)
begin
if clk'event and clk = '1' then
	if aan = '1' and aan2 = '1' then
		teller <= teller+1;				-- zorgt ervoor dat er een 0 staat wanneer 
		if teller > "0110" then			-- de dobbelsteen aan het draaien is.
			teller <= "0001";
			end if;
			end if;
if S1 = '1' then
			aan2 <= '1';
			enable(0) <= '0';
			enable(1) <= '1';
			enable(2) <= '1';
			enable(3) <= '1';
if S1 = '0' then
			aan2 <= '0';
if S2 = '1' then
		aan2 <= '1';
		enable(0) <= '1';
		enable(1) <= '0';
		enable(2) <= '1';
		enable(3) <= '1';
if S2 = '0' then
		aan2 <= '0';

end if;
end if;
end if;
end if ;
end if;
end process;


process (teller)	
	begin 
		case teller is      --        abcdefg
			WHEN  "0001"  => leds <=   "1001111"; --"0110000"
			WHEN  "0010"  => leds <=   "0010010"; --"1101101"
			WHEN  "0011"  => leds <=   "0000110"; --"1111001"
			WHEN  "0100"  => leds <=   "1001100"; --"0110011"
			WHEN  "0101"  => leds <=   "0100100"; --"1011011"
			WHEN  "0110"  => leds <=   "0100000"; --"1011111"
			WHEN OTHERs   => leds <=   "1111111"; --"0000000"
		end case;
	end process;
end Behavioral;

 

[BertVhdl]

Hi Faitie,

The problem lies in you IF statement.

It's important to use the right TAB settings in you editor, then you would see the error easily. I'll show you:

...
      if S1 = '1' then
        aan2 <= '1';
        enable(0) <= '0';
        enable(1) <= '1';
        enable(2) <= '1';
        enable(3) <= '1';
        if S1 = '0' then
          aan2 <= '0';
          if S2 = '1' then
            aan2 <= '1';
            enable(0) <= '1';
            enable(1) <= '0';
            enable(2) <= '1';
            enable(3) <= '1';
            if S2 = '0' then
              aan2 <= '0';
            
            end if;
          end if;
        end if;
      end if ;
...

No you can easily see that some parts of your code will never be reached. S1 can't be '0' and '1' at the same time!

I think you mean something like this:

...
      if S1 = '1' then
        aan2 <= '1';
        enable(0) <= '0';
        enable(1) <= '1';
        enable(2) <= '1';
        enable(3) <= '1';
      else
        
        if S2 = '1' then
          aan2 <= '1';
          enable(0) <= '1';
          enable(1) <= '0';
          enable(2) <= '1';
          enable(3) <= '1';
        else
          aan2 <= '0';  
        end if;
        
      end if ;
...

You can rewrite the code to:

...
      
      if S1 = '1' then
        enable(0) <= '0';
        enable(1) <= '1';
        enable(2) <= '1';
        enable(3) <= '1';
      elsif S2 = '1' then
        enable(0) <= '1';
        enable(1) <= '0';
        enable(2) <= '1';
        enable(3) <= '1';
      else
        -- Always describe signals in the else statement
        enable(0) <= ?
        enable(1) <= ?
        enable(2) <= ?
        enable(3) <= ?
      end if ;
      
      aan2 <= ( S1 OR S2 );
...

It's also important to describe the else statement too. In this case, you need to assign the enable signal in the else case.

Hope this helps, good luck!