----------------------------------------------------------------------------------
-- Company: Univserisy of Connecticut
-- Engineer: Igor Senderovich
-- 
-- Create Date:    03:08:15 10/09/2007 
-- Module Name:    reqFromAddr - Behavioral 
-- Description:    Request from Transc.->EthCtrl data from specified address
----------------------------------------------------------------------------------
library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
use IEEE.STD_LOGIC_ARITH.ALL;
use IEEE.STD_LOGIC_UNSIGNED.ALL;

---- Uncomment the following library declaration if instantiating
---- any Xilinx primitives in this code.
--library UNISIM;
--use UNISIM.VComponents.all;

entity reqFromAddr is
    Port ( Clk : in  STD_LOGIC;
	   Go : in STD_LOGIC;
	   A : in STD_LOGIC_VECTOR (7 downto 0);
           TxRx_Go : out STD_LOGIC := 'Z';
           TxRx_Aout : out STD_LOGIC_VECTOR (7 downto 0) := "ZZZZZZZZ";
           TxRx_RiW : out STD_LOGIC := 'Z'
	 );
end reqFromAddr;

architecture Behavioral of reqFromAddr is

	component c_delay is
	    Port ( Clk : in  STD_LOGIC;
           	   D : in  STD_LOGIC;
           	   Q : out  STD_LOGIC
		 );
	end component;

	----------------------------------------------------------------------------
	-- Note: The version of the code commented out below 
	--			guarantees data at TxRx_Go. Simplified current version expects
	--			latching on falling Clk edge in the middle of TxRx_Go pulse.
	----------------------------------------------------------------------------

	--signal Go_late : STD_LOGIC;
	--signal En : STD_LOGIC := 'Z';
	--signal Addr : STD_LOGIC_VECTOR (7 downto 0);

begin

	--u1: c_delay port map (Clk, Go, Go_late);
	
	--TxRx_Go <= '1' when Go_late='1' else 'Z';
	TxRx_Go <= '1' when Go='1' else 'Z';
	
	--TxRx_Aout <= Addr when En='1' else "ZZZZZZZZ";
	TxRx_Aout <= A when Go='1' else "ZZZZZZZZ";
	
	TxRx_RiW <= '1' when Go='1' else 'Z';
	
--	Enable : process (Go, Go_late)
--	begin
--		
--		if (Go='1') then
--			En <= '1';
--			--Addr <= A;
--		else
--			if (falling_edge(Go_late)) then
--				En <= '0';
--			else
--				En <= En;
--			end if;
--			--Addr <= Addr;
--		end if;
--		
--	end process Enable;

end Behavioral;