decod.vhd

simple thermometr in vhdl

-- Progetto Elettronica 2 FPGA (2007) - Marco Mucchino & Giovanni Schiavon
-- Decoder per circuito con 4 led a 7 segmenti

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


entity decod is
    Port ( clock : in std_logic;
	        reset : in std_logic;
	        segno : in  std_logic;
			  seq3 : in  STD_LOGIC_VECTOR (3 downto 0);
			  seq2 : in  STD_LOGIC_VECTOR (3 downto 0);
			  seq1 : in  STD_LOGIC_VECTOR (3 downto 0);
			  seqdec : in  std_logic;
	        led1 : out  STD_LOGIC_VECTOR (7 downto 0);
           led2 : out  STD_LOGIC_VECTOR (7 downto 0);
           led3 : out  STD_LOGIC_VECTOR (7 downto 0);
           leddec : out  STD_LOGIC_VECTOR (7 downto 0));
end decod;

architecture Behavioral of decod is

begin
process (clock,reset)
begin
  if ( clock'event and clock ='1') then
    if ( reset = '1') then
     led1 <= "11111111";
	  led2 <= "11111111";
	  led3 <= "11111111";
	  leddec <= "11111111";
    else

      if (segno = '1') then  led1 <= "11110111";--meno
		elsif (seq1 = "0001") then led1 <= "11101101";--1
		else led1 <= "11111111";--spento
		end if;
			
		if (seq1 = "0000" ) and (seq2 = "0000") then led2 <= "11111111";--spento
		else
					case seq2 is
						when "0000" => led2 <= "10001000";--0
						when "0001" => led2 <= "11101101";--1
						when "0010" => led2 <= "10100010";--2
						when "0011" => led2 <= "10100100";--3
						when "0100" => led2 <= "11000101";--4
						when "0101" => led2 <= "10010100";--5
						when "0110" => led2 <= "10010000";--6
						when "0111" => led2 <= "10101101";--7
						when "1000" => led2 <= "10000000";--8
						when "1001" => led2 <= "10000100";--9
						when others => led2 <= "11111111";--spento
					end case;
      end if;
			
		case seq3 is
            when "0000" => led3 <= "00001000";--0
            when "0001" => led3 <= "01101101";--1
            when "0010" => led3 <= "00100010";--2
            when "0011" => led3 <= "00100100";--3
            when "0100" => led3 <= "01000101";--4
            when "0101" => led3 <= "00010100";--5
            when "0110" => led3 <= "00010000";--6
            when "0111" => led3 <= "00101101";--7
		      when "1000" => led3 <= "00000000";--8
		      when "1001" => led3 <= "00000100";--9
            when others => led3 <= "11111111";--spento
      end case;
			
		case seqdec is
            when '0' => leddec <= "10001000";--.0
            when '1' => leddec <= "10010100";--.5
            when others => leddec <= "11111111";--spento
      end case;
    end if;
  end if;
end process;
 
end Behavioral;