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--
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--
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-- Author: John Kent
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-- Author: John Kent
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-- Date : April 2, 2004
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-- Date : April 2, 2004
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-- Interface to John Clayton's PS2 keyboard
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-- Interface to John Clayton's PS2 keyboard
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--
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--
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---------------------------------------------------------------------------------------
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---------------------------------------------------------------------------------------
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--
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--
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-- 7th Februaury 2007 - John Kent
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-- 7th Februaury 2007 - John Kent
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-- Added Generics for Keyboard Timing
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-- Added Generics for Keyboard Timing
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--
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--
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library ieee;
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library ieee;
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use ieee.std_logic_1164.all;
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use ieee.std_logic_1164.all;
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use IEEE.STD_LOGIC_ARITH.ALL;
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use IEEE.STD_LOGIC_ARITH.ALL;
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use IEEE.STD_LOGIC_UNSIGNED.ALL;
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use IEEE.STD_LOGIC_UNSIGNED.ALL;
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use ieee.numeric_std.all;
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use ieee.numeric_std.all;
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entity keyboard is
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entity keyboard is
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generic (
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generic (
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KBD_Clock_Frequency : integer
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KBD_Clock_Frequency : integer
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);
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);
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port(
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port(
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clk : in std_logic;
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clk : in std_logic;
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rst : in std_logic;
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rst : in std_logic;
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cs : in std_logic;
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cs : in std_logic;
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rw : in std_logic;
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rw : in std_logic;
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addr : in std_logic;
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addr : in std_logic;
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data_in : in std_logic_vector(7 downto 0);
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data_in : in std_logic_vector(7 downto 0);
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data_out : out std_logic_vector(7 downto 0);
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data_out : out std_logic_vector(7 downto 0);
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irq : out std_logic;
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irq : out std_logic;
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kbd_clk : inout std_logic;
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kbd_clk : inout std_logic;
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kbd_data : inout std_logic
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kbd_data : inout std_logic
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);
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);
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end keyboard;
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end keyboard;
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architecture rtl of keyboard is
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architecture rtl of keyboard is
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constant Clock_Frequency_MHz : integer := KBD_Clock_Frequency / 1000000;
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constant Clock_Frequency_MHz : integer := KBD_Clock_Frequency / 1000000;
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signal kbd_stat : std_logic_vector(7 downto 0);
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signal kbd_stat : std_logic_vector(7 downto 0);
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signal kbd_ctrl : std_logic_vector(7 downto 6);
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signal kbd_ctrl : std_logic_vector(7 downto 6);
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signal kbd_ascii_code : std_logic_vector(7 downto 0);
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signal kbd_ascii_code : std_logic_vector(7 downto 0);
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signal kbd_tx_data : std_logic_vector(7 downto 0);
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signal kbd_tx_data : std_logic_vector(7 downto 0);
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signal kbd_read : std_logic;
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signal kbd_read : std_logic;
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signal kbd_write : std_logic;
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signal kbd_write : std_logic;
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signal kbd_write_ack : std_logic;
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signal kbd_write_ack : std_logic;
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component ps2_keyboard_interface
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component ps2_keyboard_interface
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generic (
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generic (
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Frequency_MHz : integer := Clock_Frequency_MHz
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Frequency_MHz : integer := Clock_Frequency_MHz
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);
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);
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port(
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port(
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clk : in std_logic;
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clk : in std_logic;
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reset : in std_logic;
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reset : in std_logic;
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ps2_clk : inout std_logic;
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ps2_clk : inout std_logic;
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ps2_data : inout std_logic;
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ps2_data : inout std_logic;
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rx_extended : out std_logic;
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rx_extended : out std_logic;
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rx_released : out std_logic;
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rx_released : out std_logic;
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rx_shift_key_on : out std_logic;
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rx_shift_key_on : out std_logic;
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-- rx_scan_code : out std_logic_vector(7 downto 0);
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-- rx_scan_code : out std_logic_vector(7 downto 0);
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rx_ascii : out std_logic_vector(7 downto 0);
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rx_ascii : out std_logic_vector(7 downto 0);
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rx_data_ready : out std_logic; -- rx_read_o
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rx_data_ready : out std_logic; -- rx_read_o
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rx_read : in std_logic; -- rx_read_ack_i
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rx_read : in std_logic; -- rx_read_ack_i
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tx_data : in std_logic_vector(7 downto 0);
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tx_data : in std_logic_vector(7 downto 0);
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tx_write : in std_logic;
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tx_write : in std_logic;
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tx_write_ack : out std_logic;
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tx_write_ack : out std_logic;
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tx_error_no_keyboard_ack : out std_logic
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tx_error_no_keyboard_ack : out std_logic
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);
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);
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end component;
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end component;
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begin
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begin
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my_ps2_keyboard_interface : ps2_keyboard_interface
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my_ps2_keyboard_interface : ps2_keyboard_interface
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generic map (
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generic map (
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Frequency_MHz => Clock_Frequency_MHz
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Frequency_MHz => Clock_Frequency_MHz
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)
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)
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port map(
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port map(
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clk => clk,
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clk => clk,
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reset => rst,
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reset => rst,
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ps2_clk => kbd_clk,
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ps2_clk => kbd_clk,
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ps2_data => kbd_data,
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ps2_data => kbd_data,
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rx_extended => kbd_stat(2),
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rx_extended => kbd_stat(2),
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rx_released => kbd_stat(3),
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rx_released => kbd_stat(3),
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rx_shift_key_on => kbd_stat(4),
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rx_shift_key_on => kbd_stat(4),
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rx_ascii => kbd_ascii_code,
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rx_ascii => kbd_ascii_code,
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rx_data_ready => kbd_stat(0),
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rx_data_ready => kbd_stat(0),
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rx_read => kbd_read,
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rx_read => kbd_read,
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tx_data => kbd_tx_data,
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tx_data => kbd_tx_data,
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tx_write => kbd_write,
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tx_write => kbd_write,
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tx_write_ack => kbd_write_ack,
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tx_write_ack => kbd_write_ack,
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tx_error_no_keyboard_ack => kbd_stat(5)
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tx_error_no_keyboard_ack => kbd_stat(5)
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);
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);
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keyboard_strobe : process( clk, rst, cs, rw, kbd_stat )
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keyboard_strobe : process( clk, rst, cs, rw, kbd_stat )
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begin
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begin
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if( rst = '1' ) then
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if( rst = '1' ) then
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kbd_read <= '0';
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kbd_read <= '0';
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elsif( clk'event and clk='0' ) then
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elsif( clk'event and clk='0' ) then
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if( cs='1' and rw='1' and addr='1' ) then
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if( cs='1' and rw='1' and addr='1' ) then
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kbd_read <= '1';
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kbd_read <= '1';
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elsif( kbd_stat(0)='1' ) then
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elsif( kbd_stat(0)='1' ) then
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kbd_read <= '0';
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kbd_read <= '0';
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else
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else
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kbd_read <= kbd_read;
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kbd_read <= kbd_read;
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end if;
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end if;
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end if;
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end if;
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end process;
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end process;
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--
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--
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-- read keyboard registers
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-- read keyboard registers
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--
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--
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keyboard_read : process( addr, kbd_ascii_code, kbd_stat )
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keyboard_read : process( addr, kbd_ascii_code, kbd_stat )
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begin
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begin
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if( addr = '1' ) then
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if( addr = '1' ) then
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data_out <= kbd_ascii_code;
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data_out <= kbd_ascii_code;
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else
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else
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data_out <= kbd_stat;
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data_out <= kbd_stat;
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end if;
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end if;
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end process;
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end process;
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--
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--
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-- Write to keyboard register
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-- Write to keyboard register
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--
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--
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keyboard_write : process( clk, rst, cs, rw, addr, data_in, kbd_tx_data,
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keyboard_write : process( clk, rst, cs, rw, addr, data_in, kbd_tx_data,
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kbd_write, kbd_write_ack )
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kbd_write, kbd_write_ack )
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begin
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begin
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if(rst = '1' ) then
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if(rst = '1' ) then
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kbd_ctrl <= "00";
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kbd_ctrl <= "00";
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kbd_tx_data <= "00000000";
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kbd_tx_data <= "00000000";
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kbd_write <= '0';
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kbd_write <= '0';
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elsif( clk'event and clk='0' ) then
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elsif( clk'event and clk='0' ) then
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if( cs='1' and rw='0' ) then
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if( cs='1' and rw='0' ) then
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if( addr='1' ) then
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if( addr='1' ) then
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kbd_tx_data <= data_in;
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kbd_tx_data <= data_in;
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kbd_ctrl <= kbd_ctrl;
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kbd_ctrl <= kbd_ctrl;
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kbd_write <= '1';
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kbd_write <= '1';
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else
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else
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kbd_tx_data <= kbd_tx_data;
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kbd_tx_data <= kbd_tx_data;
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kbd_ctrl <= data_in(7 downto 6);
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kbd_ctrl <= data_in(7 downto 6);
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kbd_write <= kbd_write;
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kbd_write <= kbd_write;
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end if;
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end if;
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elsif( kbd_write_ack='1' ) then
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elsif( kbd_write_ack='1' ) then
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kbd_write <= '0';
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kbd_write <= '0';
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else
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else
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kbd_write <= kbd_write;
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kbd_write <= kbd_write;
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end if;
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end if;
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kbd_stat(1) <= not kbd_write;
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kbd_stat(1) <= not kbd_write;
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end if;
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end if;
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end process;
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end process;
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keyboard_interrupt : process( kbd_ctrl, kbd_stat )
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keyboard_interrupt : process( kbd_ctrl, kbd_stat )
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begin
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begin
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kbd_stat(6) <= kbd_ctrl(6);
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kbd_stat(6) <= kbd_ctrl(6);
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kbd_stat(7) <= kbd_ctrl(7) and kbd_stat(0);
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kbd_stat(7) <= kbd_ctrl(7) and kbd_stat(0);
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irq <= kbd_stat(7);
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irq <= kbd_stat(7);
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end process;
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end process;
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end rtl;
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end rtl;
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