RF Wireless World

library ieee;
use ieee.std_logic_1164.all;
use ieee.std_logic_arith.all;
use ieee.std_logic_unsigned.all;
entity key is
Port ( col: inout std_logic_vector(3 downto 0):="0001";
row : in std_logic_vector(3 downto 0);
clk : in std_logic;
disp_sel: out std_logic_vector(3 downto 0);
ss : out std_logic_vector(6 downto 0));
end key;
architecture Behavioral of key is
begin
process(clk) is
begin
if (rising_edge(clk)) then
col<=col(2 downto 0)& col(3);
end if;
end process;
disp_sel<="1110";
process(col,row)
begin
case (col) is
when "0001" => case row is
when "0001" => ss<= "1111110";
when "0010" => ss <= "0110011";
when "0100" => ss <= "1111111";
when "1000" => ss <= "1001110";
when others=> ss <= "0000000";
end case;

when "0010" => case (row) is
when "0001" => ss <= "0110000";
when "0010" => ss <= "1011011";
when "0100" => ss <= "1111011";
when "1000" => ss <= "0111101";
when others=> ss <= "0000000";
end case;

when "0100" => case (row )is
when "0001" => ss <= "1101101";
when "0010" => ss <= "1011111";
when "0100" => ss <= "1110111";
when "1000" => ss <= "1001111";
when others=> ss <= "0000000";
end case;

when "1000" => case (row)is
when "0001" => ss <= "1111001";
when "0010" => ss <= "1110000";
when "0100" => ss <= "0011111";
when "1000" => ss <= "1000111";
when others=> ss <= "0000000";
end case;

when others=> null;
end case;
end process;
end Behavioral;