IOP16 PS/2 Keyboard

PS/2 Keyboard

• Wrapper for PS/2 keyboard interfaces
• PS/2 to ASCII conversion

Software Interface

Address i_RegSel - Register Select = 0 - Status register

• Value = 0x00, No data present
• Value = 0x01, Data present

Address i_RegSel - Register Select = 0 - Data register

• ASCII Data

VHDL Entity

ENTITY Wrap_Keyboard IS
port (
  i_CLOCK_50 : IN  STD_LOGIC; -- input clock
  i_n_reset  : IN  STD_LOGIC; -- 
  i_kbCS     : IN  STD_LOGIC; -- 
  i_RegSel   : IN  STD_LOGIC; -- address
  i_rd_Kbd   : IN  STD_LOGIC; --
  i_ps2_clk  : IN  STD_LOGIC; --
  i_ps2_data : IN  STD_LOGIC; --
  o_kbdDat   : OUT STD_LOGIC_vector(7 downto 0));
end Wrap_Keyboard;

Hook-up

-- Strobes/Selects
  w_kbcs <= '1' when (w_periphAdr(7 downto 1) = "0000110")	and (w_periphRd = '1')) else '0';

-- Peripheral bus read mux
  w_periphIn <= ...
    w_KbdData  when w_periphAdr(7 downto 1) = "0000110)	else
  ...

Signals

-- Decodes/Strobes
...
 signal w_kbcs : std_logic;

-- Interfaces
...
  signal w_KbdData				:	std_logic_vector(7 downto 0);