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-------------------------------------------------------------------------------
-- Project    : Virtex-6 Integrated Block for PCI Express
-- File       : pcie_pipe_misc_v6.vhd
-- Version    : 2.3
---- Description: Misc PIPE module for Virtex6 PCIe Block
----
----
----
----------------------------------------------------------------------------------

library ieee;
   use ieee.std_logic_1164.all;

entity pcie_pipe_misc_v6 is
   generic (
      PIPE_PIPELINE_STAGES                         : integer := 0		-- 0 - 0 stages, 1 - 1 stage, 2 - 2 stages
      
   );
   port (
      pipe_tx_rcvr_det_i                           : in std_logic;
      pipe_tx_reset_i                              : in std_logic;
      pipe_tx_rate_i                               : in std_logic;
      pipe_tx_deemph_i                             : in std_logic;
      pipe_tx_margin_i                             : in std_logic_vector(2 downto 0);
      pipe_tx_swing_i                              : in std_logic;
      pipe_tx_rcvr_det_o                           : out std_logic;
      pipe_tx_reset_o                              : out std_logic;
      pipe_tx_rate_o                               : out std_logic;
      pipe_tx_deemph_o                             : out std_logic;
      pipe_tx_margin_o                             : out std_logic_vector(2 downto 0);
      pipe_tx_swing_o                              : out std_logic;
      pipe_clk                                     : in std_logic;
      rst_n                                        : in std_logic
   );
end pcie_pipe_misc_v6;

architecture v6_pcie of pcie_pipe_misc_v6 is
   
   --******************************************************************//
   -- Reality check.                                                   //
   --******************************************************************//
      
   constant TCQ                                    : integer := 1;		-- clock to out delay model

   signal pipe_tx_rcvr_det_q                       : std_logic;
   signal pipe_tx_reset_q                          : std_logic;
   signal pipe_tx_rate_q                           : std_logic;
   signal pipe_tx_deemph_q                         : std_logic;
   signal pipe_tx_margin_q                         : std_logic_vector(2 downto 0);
   signal pipe_tx_swing_q                          : std_logic;
   
   signal pipe_tx_rcvr_det_qq                      : std_logic;
   signal pipe_tx_reset_qq                         : std_logic;
   signal pipe_tx_rate_qq                          : std_logic;
   signal pipe_tx_deemph_qq                        : std_logic;
   signal pipe_tx_margin_qq                        : std_logic_vector(2 downto 0);
   signal pipe_tx_swing_qq                         : std_logic;
begin
   
   v6pcie0 : if (PIPE_PIPELINE_STAGES = 0) generate
      
      pipe_tx_rcvr_det_o <= pipe_tx_rcvr_det_i;
      pipe_tx_reset_o <= pipe_tx_reset_i;
      pipe_tx_rate_o <= pipe_tx_rate_i;
      pipe_tx_deemph_o <= pipe_tx_deemph_i;
      pipe_tx_margin_o <= pipe_tx_margin_i;
      pipe_tx_swing_o <= pipe_tx_swing_i;
      
   end generate;
   v6pcie1 : if (PIPE_PIPELINE_STAGES = 1) generate
         
      process (pipe_clk)
      begin
         if (pipe_clk'event and pipe_clk = '1') then
            
            if (rst_n = '1') then
               
               pipe_tx_rcvr_det_q <= '0' after (TCQ)*1 ps;
               pipe_tx_reset_q <= '1' after (TCQ)*1 ps;
               pipe_tx_rate_q <= '0' after (TCQ)*1 ps;
               pipe_tx_deemph_q <= '1' after (TCQ)*1 ps;
               pipe_tx_margin_q <= "000" after (TCQ)*1 ps;
               pipe_tx_swing_q <= '0' after (TCQ)*1 ps;
            else
               
               pipe_tx_rcvr_det_q <= pipe_tx_rcvr_det_i after (TCQ)*1 ps;
               pipe_tx_reset_q <= pipe_tx_reset_i after (TCQ)*1 ps;
               pipe_tx_rate_q <= pipe_tx_rate_i after (TCQ)*1 ps;
               pipe_tx_deemph_q <= pipe_tx_deemph_i after (TCQ)*1 ps;
               pipe_tx_margin_q <= pipe_tx_margin_i after (TCQ)*1 ps;
               pipe_tx_swing_q <= pipe_tx_swing_i after (TCQ)*1 ps;
            end if;
         end if;
      end process;

      pipe_tx_rcvr_det_o <= pipe_tx_rcvr_det_q;
      pipe_tx_reset_o <= pipe_tx_reset_q;
      pipe_tx_rate_o <= pipe_tx_rate_q;
      pipe_tx_deemph_o <= pipe_tx_deemph_q;
      pipe_tx_margin_o <= pipe_tx_margin_q;
      pipe_tx_swing_o <= pipe_tx_swing_q;
      
   end generate;
   v6pcie2 : if (PIPE_PIPELINE_STAGES = 2) generate
            
      process (pipe_clk)
      begin
         if (pipe_clk'event and pipe_clk = '1') then
            
            if (rst_n = '1') then
               
               pipe_tx_rcvr_det_q <= '0' after (TCQ)*1 ps;
               pipe_tx_reset_q <= '1' after (TCQ)*1 ps;
               pipe_tx_rate_q <= '0' after (TCQ)*1 ps;
               pipe_tx_deemph_q <= '1' after (TCQ)*1 ps;
               pipe_tx_margin_q <= "000" after (TCQ)*1 ps;
               pipe_tx_swing_q <= '0' after (TCQ)*1 ps;

               pipe_tx_rcvr_det_qq <= '0' after (TCQ)*1 ps;
               pipe_tx_reset_qq <= '1' after (TCQ)*1 ps;
               pipe_tx_rate_qq <= '0' after (TCQ)*1 ps;
               pipe_tx_deemph_qq <= '1' after (TCQ)*1 ps;
               pipe_tx_margin_qq <= "000" after (TCQ)*1 ps;
               pipe_tx_swing_qq <= '0' after (TCQ)*1 ps;
            else
               
               pipe_tx_rcvr_det_q <= pipe_tx_rcvr_det_i after (TCQ)*1 ps;
               pipe_tx_reset_q <= pipe_tx_reset_i after (TCQ)*1 ps;
               pipe_tx_rate_q <= pipe_tx_rate_i after (TCQ)*1 ps;
               pipe_tx_deemph_q <= pipe_tx_deemph_i after (TCQ)*1 ps;
               pipe_tx_margin_q <= pipe_tx_margin_i after (TCQ)*1 ps;
               pipe_tx_swing_q <= pipe_tx_swing_i after (TCQ)*1 ps;

               pipe_tx_rcvr_det_qq <= pipe_tx_rcvr_det_q after (TCQ)*1 ps;
               pipe_tx_reset_qq <= pipe_tx_reset_q after (TCQ)*1 ps;
               pipe_tx_rate_qq <= pipe_tx_rate_q after (TCQ)*1 ps;
               pipe_tx_deemph_qq <= pipe_tx_deemph_q after (TCQ)*1 ps;
               pipe_tx_margin_qq <= pipe_tx_margin_q after (TCQ)*1 ps;
               pipe_tx_swing_qq <= pipe_tx_swing_q after (TCQ)*1 ps;
            end if;
         end if;
      end process;
            
            
      pipe_tx_rcvr_det_o <= pipe_tx_rcvr_det_qq;
      pipe_tx_reset_o <= pipe_tx_reset_qq;
      pipe_tx_rate_o <= pipe_tx_rate_qq;
      pipe_tx_deemph_o <= pipe_tx_deemph_qq;
      pipe_tx_margin_o <= pipe_tx_margin_qq;
      pipe_tx_swing_o <= pipe_tx_swing_qq;
      
   end generate;

end v6_pcie;


