diff options
Diffstat (limited to 'src/scancodefilter.vhd')
| -rw-r--r-- | src/scancodefilter.vhd | 64 |
1 files changed, 61 insertions, 3 deletions
diff --git a/src/scancodefilter.vhd b/src/scancodefilter.vhd index 518c3aa..dbdf7b7 100644 --- a/src/scancodefilter.vhd +++ b/src/scancodefilter.vhd @@ -1,6 +1,6 @@ library ieee; use ieee.std_logic_1164.all; ---use ieee.numeric_std.all; +use ieee.numeric_std.all; entity scancodefilter is port( CLK: in std_logic; -- system clock @@ -12,7 +12,65 @@ end scancodefilter; architecture Behavioral of scancodefilter is -begin - +-- init as empty key +--signal lastKey: std_logic_vector(3 downto 0) := x"a"; +signal lastNEW_DAT: std_logic := '0'; +signal DAT_OLD: std_logic_vector(7 downto 0); -- scancode preveouse input +begin + process(CLK) + begin + if (rising_edge (clk)) then + -- always set data on output + BCD <= x"a"; + SHIFT <= '0'; + lastNEW_DAT <= NEW_DAT; + DAT_OLD <= DAT_OLD; + + -- when NEW_DAT does go high + if ((lastNEW_DAT = '0') and (NEW_DAT = '1')) then + -- set DAT_OLD + DAT_OLD <= DAT; + + -- only is pervioause data is not release of key scancode and currend data + if (DAT_OLD /= x"F0" and DAT /= x"F0") then + case DAT is + when x"45" => + BCD <= std_logic_vector(to_unsigned(0, BCD'length)); + SHIFT <= '1'; + when x"16" => + BCD <= std_logic_vector(to_unsigned(1, BCD'length)); + SHIFT <= '1'; + when x"1E" => + BCD <= std_logic_vector(to_unsigned(2, BCD'length)); + SHIFT <= '1'; + when x"26" => + BCD <= std_logic_vector(to_unsigned(3, BCD'length)); + SHIFT <= '1'; + when x"25" => + BCD <= std_logic_vector(to_unsigned(4, BCD'length)); + SHIFT <= '1'; + when x"2E" => + BCD <= std_logic_vector(to_unsigned(5, BCD'length)); + SHIFT <= '1'; + when x"36" => + BCD <= std_logic_vector(to_unsigned(6, BCD'length)); + SHIFT <= '1'; + when x"3D" => + BCD <= std_logic_vector(to_unsigned(7, BCD'length)); + SHIFT <= '1'; + when x"3E" => + BCD <= std_logic_vector(to_unsigned(8, BCD'length)); + SHIFT <= '1'; + when x"46" => + BCD <= std_logic_vector(to_unsigned(9, BCD'length)); + SHIFT <= '1'; + when others => + BCD <= x"b"; + SHIFT <= '1'; + end case; + end if; + end if; + end if; + end process; end Behavioral; |