hex2led.vhd

a simple implementation of a frequency meter with the BCD-counter and the 7-segment LED display

library IEEE;
use IEEE.std_logic_1164.all;

entity HEX2LED is
    port (
        HEX: in STD_LOGIC_VECTOR (3 downto 0);
        LED: out STD_LOGIC_VECTOR (6 downto 0)
    );
end HEX2LED;

architecture behav of HEX2LED is
-- segment encoding
--      0
--     ---  
--  5 |   | 1
--     ---   <- 6
--  4 |   | 2
--     ---
--      3
begin
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 behav;