hex2led.vhd

在Xilinx环境下编写的vhdl程序

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

entity hex2led is  
    Port ( hex : in std_logic_vector(3 downto 0);  
	        led : out std_logic_vector(6 downto 0));  
end hex2led;

architecture Behavioral of hex2led is

begin
 
--HEX-to-seven-segment decoder
--   HEX:   in    STD_LOGIC_VECTOR (3 downto 0);
--   LED:   out   STD_LOGIC_VECTOR (6 downto 0);
-- 
-- segment encoding
--      0
--     ---  
--  5 |   | 1
--     ---   <- 6
--  4 |   | 2
--     ---
--      3
   	
   	with HEX SELect
   	LED<= "1111001" when "0001",   --1
        	"0100100" when "0010",   --2
         	"0110000" when "0011",   --3
         	"0011001" when "0100",   --4
         	"0010010" when "0101",   --5
         	"0000010" when "0110",   --6
         	"1111000" when "0111",   --7
         	"0000000" when "1000",   --8
         	"0010000" when "1001",   --9
         	"0001000" when "1010",   --A
         	"0000011" when "1011",   --b
         	"1000110" when "1100",   --C
         	"0100001" when "1101",   --d
         	"0000110" when "1110",   --E
         	"0001110" when "1111",   --F
         	"1000000" when others;   --0
 
 end Behavioral;