-------------------------------------------------
-- EE552 ASL and Handheld keyboard developement Code
-- This code Translates ASCII coded data to data to be used on seven segment display
-- hex_display.vhd
-- The Hex display recieves data from the 4 to eight bit decorder and 
-- displays them on the seven segment LED in Hex
-- This code outputs active high Data but the data can be modified to give out
-- Active Low data used on the FPGA inputs


library ieee;
use ieee.std_logic_1164.all;


-- The decoder has five inputs from the glove information
-- The output is decorded into eight bit data. The data is eight bit
-- hex data
entity hex_display is
    PORT ( 
--interface in is valid data recieved from the glove
      	led_data	: IN std_logic_vector(7 downto 0);
	  	enable	: IN std_logic;
		led_a : OUT  std_logic_vector(7 downto 0);
      	led_b : OUT  std_logic_vector(7 downto 0)); 
end entity hex_display;
--we use the LSB of the LED the seven segment LED outputs 
--a and b for the decimal point. => a0 & b0 = point
		
 

architecture behavioral of hex_display is
--constant datawidth : positive := 8;
signal a : std_logic_vector(7 downto 0);
signal b : std_logic_vector(7 downto 0);

begin
	  

display: process(enable,led_data) is
begin

--this basically asigns ASCII CODE to a seven segment LED display

		case led_data is 
--display 41 hex equvalent of A in Ascii

--Example of ASCII 41 = 01000001
	when 	"01000001" =>
--seven segment led assignment
a <= "01100110";
b <= "01100000";
	
	when 	"01000010" =>
a <= "01100110";
b <= "11011010";

	when	"01000011" =>
a <= "01100110";
b <= "11110010";

	when	"01000100" =>
a <= "01100110";
b <= "01100110";

	when	"01000101" =>
a <= "01100110";
b <= "10110110";

	when	"01000110" =>
a <= "01100110";
b <= "10111110";
			
	when	"01000111" =>
a <= "01100110";
b <= "11100000";
			
	when	"01001000" =>
a <= "01100110";
b <= "11111110";
			
	when	"01001001" =>
a <= "01100110";
b <= "11110110";
			
	when 	"01001010" =>
a <= "01100110";
b <= "11101110";
			
	when 	"01001011" =>
a <= "01100110";
b <= "00111110";
	
	when 	"01001100" =>
a <= "01100110";
b <= "10011100";
			
	when	"01001101" =>
a <= "01100110";
b <= "01111010";
			
	when	"01001110" =>
a <= "01100110";
b <= "10011110";
			
	when	"01001111" =>
a <= "01100110";
b <= "10001110";
	
	when	"01010000" =>
a <= "01101101";
b <= "11111100";
	
	when	"01010001" =>
a <= "01101101";
b <= "01100000";
			
	when	"01010010" =>
a <= "01101101";
b <= "11011010";
	
	when	"01010011" =>
a <= "01101101";
b <= "11110010";
			
	when	"01010100" =>
a <= "01101101";
b <= "01100110";

	when	"01010101" =>
a <= "01101101";
b <= "10110110";

	when	"01010110" =>
a <= "01101101";
b <= "10111110";

	when	"01010111" =>
a <= "01101101";
b <= "11100000";

	when	"01011000" =>
a <= "01101101";
b <= "11111110";
			
	when	"01011001" =>
a <= "01101101";
b <= "11110110";
			
	when	"01011010" =>
a <= "01101101";
b <= "11101110";

	when	"00100000" =>
a <="00000001";
b <= "00000001";

	when	"00001000" =>
a <="00000000";
b <= "00000000";

	when	"00101110" =>
a <="00000001";
b <= "00000000";

	when	"00101101" =>
a <="00000000";
b <= "00000000";

	when	"00001101" =>
a <="00000000";
b <= "00000000";

		when others =>
a <="00000000";
b <= "00000001";

			end case;
--inevert ouputs to active low

	
			end process display;
	led_a <=  not a;
	led_b <=  not b;
end behavioral;