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[/] [System09/] [trunk/] [rtl/] [VHDL/] [keyboard.vhd] - Rev 74
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--------------------------------------------------------------------------------------- -- -- Author: John Kent -- Date : April 2, 2004 -- Interface to John Clayton's PS2 keyboard -- --------------------------------------------------------------------------------------- -- -- 7th Februaury 2007 - John Kent -- Added Generics for Keyboard Timing -- library ieee; use ieee.std_logic_1164.all; use IEEE.STD_LOGIC_ARITH.ALL; use IEEE.STD_LOGIC_UNSIGNED.ALL; use ieee.numeric_std.all; entity keyboard is generic ( KBD_Clock_Frequency : integer ); port( clk : in std_logic; rst : in std_logic; cs : in std_logic; rw : in std_logic; addr : in std_logic; data_in : in std_logic_vector(7 downto 0); data_out : out std_logic_vector(7 downto 0); irq : out std_logic; kbd_clk : inout std_logic; kbd_data : inout std_logic ); end keyboard; architecture rtl of keyboard is constant Clock_Frequency_MHz : integer := KBD_Clock_Frequency / 1000000; signal kbd_stat : std_logic_vector(7 downto 0); signal kbd_ctrl : std_logic_vector(7 downto 6); signal kbd_ascii_code : std_logic_vector(7 downto 0); signal kbd_tx_data : std_logic_vector(7 downto 0); signal kbd_read : std_logic; signal kbd_write : std_logic; signal kbd_write_ack : std_logic; component ps2_keyboard_interface generic ( Frequency_MHz : integer := Clock_Frequency_MHz ); port( clk : in std_logic; reset : in std_logic; ps2_clk : inout std_logic; ps2_data : inout std_logic; rx_extended : out std_logic; rx_released : out std_logic; rx_shift_key_on : out std_logic; -- rx_scan_code : out std_logic_vector(7 downto 0); rx_ascii : out std_logic_vector(7 downto 0); rx_data_ready : out std_logic; -- rx_read_o rx_read : in std_logic; -- rx_read_ack_i tx_data : in std_logic_vector(7 downto 0); tx_write : in std_logic; tx_write_ack : out std_logic; tx_error_no_keyboard_ack : out std_logic ); end component; begin my_ps2_keyboard_interface : ps2_keyboard_interface generic map ( Frequency_MHz => Clock_Frequency_MHz ) port map( clk => clk, reset => rst, ps2_clk => kbd_clk, ps2_data => kbd_data, rx_extended => kbd_stat(2), rx_released => kbd_stat(3), rx_shift_key_on => kbd_stat(4), rx_ascii => kbd_ascii_code, rx_data_ready => kbd_stat(0), rx_read => kbd_read, tx_data => kbd_tx_data, tx_write => kbd_write, tx_write_ack => kbd_write_ack, tx_error_no_keyboard_ack => kbd_stat(5) ); keyboard_strobe : process( clk, rst, cs, rw, kbd_stat ) begin if( rst = '1' ) then kbd_read <= '0'; elsif( clk'event and clk='0' ) then if( cs='1' and rw='1' and addr='1' ) then kbd_read <= '1'; elsif( kbd_stat(0)='1' ) then kbd_read <= '0'; else kbd_read <= kbd_read; end if; end if; end process; -- -- read keyboard registers -- keyboard_read : process( addr, kbd_ascii_code, kbd_stat ) begin if( addr = '1' ) then data_out <= kbd_ascii_code; else data_out <= kbd_stat; end if; end process; -- -- Write to keyboard register -- keyboard_write : process( clk, rst, cs, rw, addr, data_in, kbd_tx_data, kbd_write, kbd_write_ack ) begin if(rst = '1' ) then kbd_ctrl <= "00"; kbd_tx_data <= "00000000"; kbd_write <= '0'; elsif( clk'event and clk='0' ) then if( cs='1' and rw='0' ) then if( addr='1' ) then kbd_tx_data <= data_in; kbd_ctrl <= kbd_ctrl; kbd_write <= '1'; else kbd_tx_data <= kbd_tx_data; kbd_ctrl <= data_in(7 downto 6); kbd_write <= kbd_write; end if; elsif( kbd_write_ack='1' ) then kbd_write <= '0'; else kbd_write <= kbd_write; end if; kbd_stat(1) <= not kbd_write; end if; end process; keyboard_interrupt : process( kbd_ctrl, kbd_stat ) begin kbd_stat(6) <= kbd_ctrl(6); kbd_stat(7) <= kbd_ctrl(7) and kbd_stat(0); irq <= kbd_stat(7); end process; end rtl;
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