Subversion Repositories pcie_sg_dma

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-- Company: 

-- Engineer: 

-- 

-- Design Name: 

-- Module Name:    usDMA_Transact - Behavioral 

-- Project Name: 

-- Target Devices: 

-- Tool versions: 

-- Description: 

--

-- Dependencies: 

--

-- Revision 1.20 - DMA engine shared out.   12.02.2007

--

-- Revision 1.10 - x4 timing constraints met.   02.02.2007

--

-- Revision 1.04 - Timing improved.     17.01.2007

--

-- Revision 1.02 - FIFO added.    20.12.2006

--

-- Revision 1.00 - first release. 14.12.2006

-- 

-- Additional Comments: 

--

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library IEEE;

use IEEE.STD_LOGIC_1164.ALL;

use IEEE.STD_LOGIC_ARITH.ALL;

use IEEE.STD_LOGIC_UNSIGNED.ALL;

library work;

use work.abb64Package.all;

-- Uncomment the following library declaration if instantiating

-- any Xilinx primitives in this code.

--library UNISIM;

--use UNISIM.VComponents.all;

entity usDMA_Transact is

    port (

      -- Around the Channel Buffer

      usTlp_Req          : OUT std_logic;

      usTlp_RE           : IN  std_logic;

      usTlp_Qout         : OUT std_logic_vector(C_CHANNEL_BUF_WIDTH-1 downto 0);

      us_FC_stop         : IN  std_logic;

      us_Last_sof        : IN  std_logic;

      us_Last_eof        : IN  std_logic;

      FIFO_Data_Count    : IN  std_logic_vector(C_FIFO_DC_WIDTH downto 0);

      FIFO_Reading       : IN  std_logic;

      -- Upstream reset from MWr channel

      usDMA_Channel_Rst  : IN  std_logic;

      -- Upstream Registers from MWr Channel

      DMA_us_PA          : IN  std_logic_vector(C_DBUS_WIDTH-1 downto 0);

      DMA_us_HA          : IN  std_logic_vector(C_DBUS_WIDTH-1 downto 0);

      DMA_us_BDA         : IN  std_logic_vector(C_DBUS_WIDTH-1 downto 0);

      DMA_us_Length      : IN  std_logic_vector(C_DBUS_WIDTH-1 downto 0);

      DMA_us_Control     : IN  std_logic_vector(C_DBUS_WIDTH-1 downto 0);

      usDMA_BDA_eq_Null  : IN  std_logic;

      us_MWr_Param_Vec   : IN  std_logic_vector(6-1   downto 0);

      -- Calculation in advance, for better timing

      usHA_is_64b        : IN  std_logic;

      usBDA_is_64b       : IN  std_logic;

      -- Calculation in advance, for better timing

      usLeng_Hi19b_True  : IN  std_logic;

      usLeng_Lo7b_True   : IN  std_logic;

      -- from Cpl/D channel

      usDMA_dex_Tag      : IN  std_logic_vector(C_TAG_WIDTH-1 downto 0);

      -- Upstream Control Signals from MWr Channel

      usDMA_Start        : IN  std_logic;   -- out of 1st dex

      usDMA_Stop         : IN  std_logic;   -- out of 1st dex

      -- Upstream Control Signals from CplD Channel

      usDMA_Start2       : IN  std_logic;   -- out of consecutive dex

      usDMA_Stop2        : IN  std_logic;   -- out of consecutive dex

      -- Upstream DMA Acknowledge to the start command

      DMA_Cmd_Ack        : OUT std_logic;

      -- To Interrupt module

      DMA_Done           : OUT std_logic;

      DMA_TimeOut        : OUT std_logic;

      DMA_Busy           : OUT std_logic;

      -- To Registers' Group

      DMA_us_Status      : OUT std_logic_vector(C_DBUS_WIDTH-1 downto 0);

      -- Additional

      cfg_dcommand       : IN  std_logic_vector(C_CFG_COMMAND_DWIDTH-1 downto 0);

       -- Common ports

      trn_clk            : IN  std_logic

    );

end entity usDMA_Transact;

architecture Behavioral of usDMA_Transact is

  -- Upstream DMA channel

  signal  Local_Reset_i        : std_logic;

  signal  DMA_Status_i         : std_logic_vector(C_DBUS_WIDTH-1 downto 0);

  signal  cfg_MPS              : std_logic_vector(C_CFG_MPS_BIT_TOP-C_CFG_MPS_BIT_BOT downto 0);

  signal  usDMA_MWr_Tag        : std_logic_vector(C_TAG_WIDTH-1 downto  0);

  -- DMA calculation

  COMPONENT DMA_Calculate

    PORT(

      -- Downstream Registers from MWr Channel

      DMA_PA             : IN  std_logic_vector(C_DBUS_WIDTH-1 downto 0);  -- EP   (local)

      DMA_HA             : IN  std_logic_vector(C_DBUS_WIDTH-1 downto 0);  -- Host (remote)

      DMA_BDA            : IN  std_logic_vector(C_DBUS_WIDTH-1 downto 0);

      DMA_Length         : IN  std_logic_vector(C_DBUS_WIDTH-1 downto 0);

      DMA_Control        : IN  std_logic_vector(C_DBUS_WIDTH-1 downto 0);

      -- Calculation in advance, for better timing

      HA_is_64b          : IN  std_logic;

      BDA_is_64b         : IN  std_logic;

      -- Calculation in advance, for better timing

      Leng_Hi19b_True    : IN  std_logic;

      Leng_Lo7b_True     : IN  std_logic;

      -- Parameters fed to DMA_FSM

      DMA_PA_Loaded      : OUT std_logic_vector(C_DBUS_WIDTH-1 downto 0);

      DMA_PA_Var         : OUT std_logic_vector(C_DBUS_WIDTH-1 downto 0);

      DMA_HA_Var         : OUT std_logic_vector(C_DBUS_WIDTH-1 downto 0);

      DMA_BDA_fsm        : OUT std_logic_vector(C_DBUS_WIDTH-1 downto 0);

      BDA_is_64b_fsm     : OUT std_logic;

      -- Only for downstream channel

      DMA_PA_Snout       : OUT std_logic_vector(C_DBUS_WIDTH-1 downto 0);

      DMA_BAR_Number     : OUT std_logic_vector(C_TAGBAR_BIT_TOP-C_TAGBAR_BIT_BOT downto 0);

      -- 

      DMA_Snout_Length   : OUT std_logic_vector(C_MAXSIZE_FLD_BIT_TOP downto 0);

      DMA_Body_Length    : OUT std_logic_vector(C_MAXSIZE_FLD_BIT_TOP downto 0);

      DMA_Tail_Length    : OUT std_logic_vector(C_TLP_FLD_WIDTH_OF_LENG+1 downto 0);

      -- Engine control signals

      DMA_Start          : IN  std_logic;

      DMA_Start2         : IN  std_logic;   -- out of consecutive dex

      -- Control signals to FSM

      No_More_Bodies     : OUT std_logic;

      ThereIs_Snout      : OUT std_logic;

      ThereIs_Body       : OUT std_logic;

      ThereIs_Tail       : OUT std_logic;

      ThereIs_Dex        : OUT std_logic;

      HA64bit            : OUT std_logic;

      Addr_Inc           : OUT std_logic;

      -- FSM indicators

      State_Is_LoadParam : IN  std_logic;

      State_Is_Snout     : IN  std_logic;

      State_Is_Body      : IN  std_logic;

--      State_Is_Tail      : IN  std_logic;

      -- Additional

      Param_Max_Cfg      : IN  std_logic_vector(2 downto 0);

      -- Common ports

      dma_clk            : IN  std_logic;

      dma_reset          : IN  std_logic

      );

  END COMPONENT;

  signal  usDMA_PA_Loaded      : std_logic_vector(C_DBUS_WIDTH-1 downto 0);

  signal  usDMA_PA_Var         : std_logic_vector(C_DBUS_WIDTH-1 downto 0);

  signal  usDMA_HA_Var         : std_logic_vector(C_DBUS_WIDTH-1 downto 0);

  signal  usDMA_BDA_fsm        : std_logic_vector(C_DBUS_WIDTH-1 downto 0);

  signal  usBDA_is_64b_fsm     : std_logic;

  signal  usDMA_PA_snout       : std_logic_vector(C_DBUS_WIDTH-1 downto 0);

  signal  usDMA_BAR_Number     : std_logic_vector(C_TAGBAR_BIT_TOP-C_TAGBAR_BIT_BOT downto 0);

  signal  usDMA_Snout_Length   : std_logic_vector(C_MAXSIZE_FLD_BIT_TOP downto 0);

  signal  usDMA_Body_Length    : std_logic_vector(C_MAXSIZE_FLD_BIT_TOP downto 0);

  signal  usDMA_Tail_Length    : std_logic_vector(C_TLP_FLD_WIDTH_OF_LENG+1 downto 0);

  signal  usNo_More_Bodies     : std_logic;

  signal  usThereIs_Snout      : std_logic;

  signal  usThereIs_Body       : std_logic;

  signal  usThereIs_Tail       : std_logic;

  signal  usThereIs_Dex        : std_logic;

  signal  usHA64bit            : std_logic;

  signal  us_AInc              : std_logic;

  -- DMA state machine

  COMPONENT DMA_FSM

    PORT(

      -- Fixed information for 1st header of TLP: MRd/MWr

      TLP_Has_Payload    : IN  std_logic;

      TLP_Hdr_is_4DW     : IN  std_logic;

      DMA_Addr_Inc       : IN  std_logic;

      DMA_BAR_Number     : IN  std_logic_vector(C_TAGBAR_BIT_TOP-C_TAGBAR_BIT_BOT downto 0);

      -- FSM control signals

      DMA_Start          : IN  std_logic;

      DMA_Start2         : IN  std_logic;

      DMA_Stop           : IN  std_logic;

      DMA_Stop2          : IN  std_logic;

      No_More_Bodies     : IN  std_logic;

      ThereIs_Snout      : IN  std_logic;

      ThereIs_Body       : IN  std_logic;

      ThereIs_Tail       : IN  std_logic;

      ThereIs_Dex        : IN  std_logic;

      -- Parameters to be written into ChBuf

      DMA_PA_Loaded      : IN  std_logic_vector(C_DBUS_WIDTH-1 downto 0);

      DMA_PA_Var         : IN  std_logic_vector(C_DBUS_WIDTH-1 downto 0);

      DMA_HA_Var         : IN  std_logic_vector(C_DBUS_WIDTH-1 downto 0);

      DMA_BDA_fsm        : IN  std_logic_vector(C_DBUS_WIDTH-1 downto 0);

      BDA_is_64b_fsm     : IN  std_logic;

      DMA_Snout_Length   : IN  std_logic_vector(C_MAXSIZE_FLD_BIT_TOP downto 0);

      DMA_Body_Length    : IN  std_logic_vector(C_MAXSIZE_FLD_BIT_TOP downto 0);

      DMA_Tail_Length    : IN  std_logic_vector(C_TLP_FLD_WIDTH_OF_LENG+1 downto 0);

      -- Busy/Done conditions

      Done_Condition_1   : IN  std_logic;

      Done_Condition_2   : IN  std_logic;

      Done_Condition_3   : IN  std_logic;

      Done_Condition_4   : IN  std_logic;

      Done_Condition_5   : IN  std_logic;

      -- Channel buffer write

      us_MWr_Param_Vec   : IN  std_logic_vector(6-1   downto 0);

      ChBuf_aFull        : IN  std_logic;

      ChBuf_WrEn         : OUT std_logic;

      ChBuf_WrDin        : OUT std_logic_vector(C_CHANNEL_BUF_WIDTH-1 downto 0);

      -- FSM indicators

      State_Is_LoadParam : OUT std_logic;

      State_Is_Snout     : OUT std_logic;

      State_Is_Body      : OUT std_logic;

      State_Is_Tail      : OUT std_logic;

      DMA_Cmd_Ack        : OUT std_logic;

      -- To Tx Port

      ChBuf_ValidRd      : IN  std_logic;

      BDA_nAligned       : OUT std_logic;

      DMA_TimeOut        : OUT std_logic;

      DMA_Busy           : OUT std_logic;

      DMA_Done           : OUT std_logic;

--      DMA_Done_Rise      : OUT std_logic;

      -- Tags

      Pkt_Tag            : IN  std_logic_vector(C_TAG_WIDTH-1 downto 0);

      Dex_Tag            : IN  std_logic_vector(C_TAG_WIDTH-1 downto 0);

      -- Common ports

      dma_clk            : IN  std_logic;

      dma_reset          : IN  std_logic

    );

  END COMPONENT;

  -- FSM state indicators

  signal  usState_Is_LoadParam : std_logic;

  signal  usState_Is_Snout     : std_logic;

  signal  usState_Is_Body      : std_logic;

  signal  usState_Is_Tail      : std_logic;

  signal  usChBuf_ValidRd      : std_logic;

  signal  usBDA_nAligned       : std_logic;

  signal  usDMA_TimeOut_i      : std_logic;

  signal  usDMA_Busy_i         : std_logic;

  signal  usDMA_Done_i         : std_logic;

  -- Built-in single-port fifo as downstream DMA channel buffer

  --   128-bit wide, for 64-bit address

  component v6_sfifo_15x128

    port (

          clk                  : IN  std_logic;

          rst                  : IN  std_logic;

          prog_full            : OUT std_logic;

--          wr_clk             : IN  std_logic;

          wr_en                : IN  std_logic;

          din                  : IN  std_logic_VECTOR(C_CHANNEL_BUF_WIDTH-1 downto 0);

          full                 : OUT std_logic;

--          rd_clk             : IN  std_logic;

          rd_en                : IN  std_logic;

          dout                 : OUT std_logic_VECTOR(C_CHANNEL_BUF_WIDTH-1 downto 0);

          prog_empty           : OUT std_logic;

          empty                : OUT std_logic

    );

  end component;

  -- Signal with DMA_upstream channel abstract buffer

  signal  usTlp_din            : std_logic_vector(C_CHANNEL_BUF_WIDTH-1 downto 0);

  signal  usTlp_Qout_wire      : std_logic_vector(C_CHANNEL_BUF_WIDTH-1 downto 0);

  signal  usTlp_Qout_reg       : std_logic_vector(C_CHANNEL_BUF_WIDTH-1 downto 0);

  signal  usTlp_Qout_i         : std_logic_vector(C_CHANNEL_BUF_WIDTH-1 downto 0);

  signal  usTlp_RE_i           : std_logic;

  signal  usTlp_RE_i_r1        : std_logic;

  signal  usTlp_we             : std_logic;

  signal  usTlp_empty_i        : std_logic;

  signal  usTlp_full           : std_logic;

  signal  usTlp_prog_Full      : std_logic;

  signal  usTlp_pempty         : std_logic;

  signal  usTlp_Npempty_r1     : std_logic;

  signal  usTlp_Nempty_r1      : std_logic;

  signal  usTlp_empty_r1       : std_logic;

  signal  usTlp_empty_r2       : std_logic;

  signal  usTlp_empty_r3       : std_logic;

  signal  usTlp_empty_r4       : std_logic;

  signal  usTlp_prog_Full_r1   : std_logic;

  -- Request for output arbitration

  signal  usTlp_Req_i          : std_logic;

  signal  usTlp_nReq_r1        : std_logic;

  signal  FIFO_Reading_r1      : std_logic;

  signal  FIFO_Reading_r2      : std_logic;

  signal  FIFO_Reading_r3p     : std_logic;

  signal  usTlp_MWr_Leng       : std_logic_vector(C_TLP_FLD_WIDTH_OF_LENG-1 downto 0);

  -- Busy/Done state bits generation

  type FSM_Request is         (

                                 REQST_Idle

                               , REQST_1Read

                               , REQST_Decision

                               , REQST_nFIFO_Req

                               , REQST_Quantity

                               , REQST_FIFO_Req

                               );

  signal FSM_REQ_us           : FSM_Request;

begin

   -- DMA done signal

   DMA_Done           <= usDMA_Done_i;

   DMA_TimeOut        <= usDMA_TimeOut_i;

   DMA_Busy           <= usDMA_Busy_i;

   -- connecting FIFO's signals

   usTlp_Qout         <= usTlp_Qout_i;

   usTlp_Req          <= usTlp_Req_i and not FIFO_Reading_r3p;

   -- positive local reset

   Local_Reset_i      <= usDMA_Channel_Rst;

   -- Max Payload Size bits

   cfg_MPS            <= cfg_dcommand(C_CFG_MPS_BIT_TOP downto C_CFG_MPS_BIT_BOT);

   -- Kernel Engine

   us_DMA_Calculation:

   DMA_Calculate

   PORT MAP(

            DMA_PA             => DMA_us_PA        ,

            DMA_HA             => DMA_us_HA        ,

            DMA_BDA            => DMA_us_BDA       ,

            DMA_Length         => DMA_us_Length    ,

            DMA_Control        => DMA_us_Control   ,

            HA_is_64b          => usHA_is_64b        ,

            BDA_is_64b         => usBDA_is_64b       ,

            Leng_Hi19b_True    => usLeng_Hi19b_True  ,

            Leng_Lo7b_True     => usLeng_Lo7b_True   ,

            DMA_PA_Loaded      => usDMA_PA_Loaded  ,

            DMA_PA_Var         => usDMA_PA_Var     ,

            DMA_HA_Var         => usDMA_HA_Var     ,

            DMA_BDA_fsm        => usDMA_BDA_fsm    ,

            BDA_is_64b_fsm     => usBDA_is_64b_fsm ,

            -- Only for downstream channel

            DMA_PA_Snout       => usDMA_PA_snout   ,

            DMA_BAR_Number     => usDMA_BAR_Number ,

            -- Lengths

            DMA_Snout_Length   => usDMA_Snout_Length ,

            DMA_Body_Length    => usDMA_Body_Length  ,

            DMA_Tail_Length    => usDMA_Tail_Length  ,

            -- Control signals to FSM

            No_More_Bodies     => usNo_More_Bodies   ,

            ThereIs_Snout      => usThereIs_Snout    ,

            ThereIs_Body       => usThereIs_Body     ,

            ThereIs_Tail       => usThereIs_Tail     ,

            ThereIs_Dex        => usThereIs_Dex      ,

            HA64bit            => usHA64bit          ,

            Addr_Inc           => us_AInc            ,

            DMA_Start          => usDMA_Start       ,

            DMA_Start2         => usDMA_Start2      ,

            State_Is_LoadParam => usState_Is_LoadParam ,

            State_Is_Snout     => usState_Is_Snout     ,

            State_Is_Body      => usState_Is_Body      ,

--            State_Is_Tail      => usState_Is_Tail      ,

            Param_Max_Cfg      => cfg_MPS       ,

            dma_clk            => trn_clk       ,

            dma_reset          => Local_Reset_i

   );

   -- Kernel FSM

   us_DMA_StateMachine:

   DMA_FSM

   PORT MAP(

            TLP_Has_Payload    => '1'               ,

            TLP_Hdr_is_4DW     => usHA64bit         ,

            DMA_Addr_Inc       => us_AInc           ,

            DMA_BAR_Number     => usDMA_BAR_Number  ,

            DMA_Start          => usDMA_Start       ,

            DMA_Start2         => usDMA_Start2      ,

            DMA_Stop           => usDMA_Stop        ,

            DMA_Stop2          => usDMA_Stop2       ,

            -- Control signals to FSM

            No_More_Bodies     => usNo_More_Bodies   ,

            ThereIs_Snout      => usThereIs_Snout    ,

            ThereIs_Body       => usThereIs_Body     ,

            ThereIs_Tail       => usThereIs_Tail     ,

            ThereIs_Dex        => usThereIs_Dex      ,

            DMA_PA_Loaded      => usDMA_PA_Loaded  ,

            DMA_PA_Var         => usDMA_PA_Var     ,

            DMA_HA_Var         => usDMA_HA_Var     ,

            DMA_BDA_fsm        => usDMA_BDA_fsm    ,

            BDA_is_64b_fsm     => usBDA_is_64b_fsm ,

            DMA_Snout_Length   => usDMA_Snout_Length ,

            DMA_Body_Length    => usDMA_Body_Length  ,

            DMA_Tail_Length    => usDMA_Tail_Length  ,

            ChBuf_ValidRd      => usChBuf_ValidRd    ,

            BDA_nAligned       => usBDA_nAligned     ,

            DMA_TimeOut        => usDMA_TimeOut_i    ,

            DMA_Busy           => usDMA_Busy_i       ,

            DMA_Done           => usDMA_Done_i       ,

--            DMA_Done_Rise      => open             ,

            Pkt_Tag            => usDMA_MWr_Tag      ,

            Dex_Tag            => usDMA_dex_Tag      ,

            Done_Condition_1   => '1'                ,

            Done_Condition_2   => usTlp_empty_r3     ,

            Done_Condition_3   => usTlp_nReq_r1      ,

            Done_Condition_4   => us_Last_sof        ,

            Done_Condition_5   => us_Last_eof        ,

            us_MWr_Param_Vec   => us_MWr_Param_Vec   ,

            ChBuf_aFull        => usTlp_Npempty_r1   ,  -- usTlp_prog_Full_r1 ,

            ChBuf_WrEn         => usTlp_we           ,

            ChBuf_WrDin        => usTlp_din          ,

            State_Is_LoadParam => usState_Is_LoadParam ,

            State_Is_Snout     => usState_Is_Snout     ,

            State_Is_Body      => usState_Is_Body      ,

            State_Is_Tail      => usState_Is_Tail      ,

            DMA_Cmd_Ack        => DMA_Cmd_Ack     ,

            dma_clk            => trn_clk         ,

            dma_reset          => Local_Reset_i

   );

   usChBuf_ValidRd     <= usTlp_RE;  -- usTlp_RE_i and not usTlp_empty_i;

-- -------------------------------------------------

-- 

   DMA_us_Status       <= DMA_Status_i;

-- 

-- Synchronous output: DMA_Status_i

-- 

   US_DMA_Status_Concat:

   process ( trn_clk, Local_Reset_i)

   begin

      if Local_Reset_i = '1' then

         DMA_Status_i <= (OTHERS =>'0');

      elsif trn_clk'event and trn_clk = '1' then

         DMA_Status_i <= (

                          CINT_BIT_DMA_STAT_NALIGN  => usBDA_nAligned,

                          CINT_BIT_DMA_STAT_TIMEOUT => usDMA_TimeOut_i,

                          CINT_BIT_DMA_STAT_BDANULL => usDMA_BDA_eq_Null,

                          CINT_BIT_DMA_STAT_BUSY    => usDMA_Busy_i,

                          CINT_BIT_DMA_STAT_DONE    => usDMA_Done_i,

                          Others                    => '0'

                         );

      end if;

   end process;

-- -----------------------------------

-- Synchronous Register: usDMA_MWr_Tag

   FSM_usDMA_usDMA_MWr_Tag:

   process ( trn_clk, Local_Reset_i)

   begin

      if Local_Reset_i = '1' then

         usDMA_MWr_Tag     <= C_TAG0_DMA_US_MWR;

      elsif trn_clk'event and trn_clk = '1' then

         if    usState_Is_Snout='1'

            or usState_Is_Body='1'

            or usState_Is_Tail='1'

            then

                -- Only 4 lower bits increment, higher 4 stay

            usDMA_MWr_Tag(C_TAG_WIDTH-C_TAG_DECODE_BITS-1 downto 0)

         <= usDMA_MWr_Tag(C_TAG_WIDTH-C_TAG_DECODE_BITS-1 downto 0)

          + CONV_STD_LOGIC_VECTOR(1, C_TAG_WIDTH-C_TAG_DECODE_BITS);

         else

            usDMA_MWr_Tag <= usDMA_MWr_Tag;

         end if;

      end if;

   end process;

   -- -------------------------------------------------

   -- us MWr/MRd TLP Buffer

   -- -------------------------------------------------

   US_TLP_Buffer:

   v6_sfifo_15x128

      port map (

         clk           => trn_clk,

         rst           => Local_Reset_i,

         prog_full     => usTlp_prog_Full ,

--         wr_clk        => trn_clk,

         wr_en         => usTlp_we,

         din           => usTlp_din,

         full          => usTlp_full,

--         rd_clk        => trn_clk,

         rd_en         => usTlp_RE_i,

         dout          => usTlp_Qout_wire,

         prog_empty    => usTlp_pempty,

         empty         => usTlp_empty_i

       );

-- ---------------------------------------------

--  Synchronous delay

-- 

   Synch_Delay_ren_Qout:

   process (Local_Reset_i, trn_clk )

   begin

      if Local_Reset_i = '1' then

         FIFO_Reading_r1 <= '0';

         FIFO_Reading_r2 <= '0';

         FIFO_Reading_r3p<= '0';

         usTlp_RE_i_r1   <= '0';

         usTlp_nReq_r1   <= '0';

         usTlp_Qout_reg  <= (OTHERS=>'0');

         usTlp_MWr_Leng  <= (OTHERS=>'0');

      elsif trn_clk'event and trn_clk = '1' then

         FIFO_Reading_r1 <= FIFO_Reading;

         FIFO_Reading_r2 <= FIFO_Reading_r1;

         FIFO_Reading_r3p<= FIFO_Reading_r1 or FIFO_Reading_r2;

         usTlp_RE_i_r1  <= usTlp_RE_i;

         usTlp_nReq_r1  <= not usTlp_Req_i;

         if usTlp_RE_i_r1='1' then

            usTlp_Qout_reg <= usTlp_Qout_wire;

            usTlp_MWr_Leng <= usTlp_Qout_wire(C_CHBUF_LENG_BIT_TOP downto C_CHBUF_LENG_BIT_BOT);

         else

            usTlp_Qout_reg <= usTlp_Qout_reg;

            usTlp_MWr_Leng <= usTlp_MWr_Leng;

         end if;

      end if;

   end process;

-- ---------------------------------------------

--  Request for arbitration

-- 

   Synch_Req_Proc:

   process (Local_Reset_i, trn_clk )

   begin

      if Local_Reset_i = '1' then

         usTlp_RE_i     <= '0';

         usTlp_Req_i    <= '0';

         FSM_REQ_us     <= REQST_IDLE;

      elsif trn_clk'event and trn_clk = '1' then

         case FSM_REQ_us  is

           when REQST_IDLE  =>

             if usTlp_empty_i = '0' then

               usTlp_RE_i   <= '1';

               usTlp_Req_i  <= '0';

               FSM_REQ_us   <= REQST_1Read;

             else

               usTlp_RE_i   <= '0';

               usTlp_Req_i  <= '0';

               FSM_REQ_us   <= REQST_IDLE;

             end if;

           when REQST_1Read  =>

             usTlp_RE_i   <= '0';

             usTlp_Req_i  <= '0';

             FSM_REQ_us   <= REQST_Decision;

           when REQST_Decision  =>

             if usTlp_Qout_wire(C_CHBUF_FMT_BIT_TOP) = '1'  -- Has Payload

               and usTlp_Qout_wire(C_CHBUF_DMA_BAR_BIT_TOP downto C_CHBUF_DMA_BAR_BIT_BOT)

                   =CONV_STD_LOGIC_VECTOR(CINT_FIFO_SPACE_BAR, C_ENCODE_BAR_NUMBER)

               then

               usTlp_RE_i  <= '0';

               usTlp_Req_i <= '0';

               FSM_REQ_us  <= REQST_Quantity;

             else

               usTlp_RE_i  <= '0';

               usTlp_Req_i <=  not usDMA_Stop

                           and not usDMA_Stop2

                           and not us_FC_stop;

               FSM_REQ_us  <= REQST_nFIFO_Req;

             end if;

           when REQST_nFIFO_Req  =>

             if usTlp_RE = '1' then

               usTlp_RE_i   <= '0';

               usTlp_Req_i  <= '0';

               FSM_REQ_us   <= REQST_IDLE;

             else

               usTlp_RE_i   <= '0';

               usTlp_Req_i  <=  not usDMA_Stop

                            and not usDMA_Stop2

                            and not us_FC_stop;

               FSM_REQ_us   <= REQST_nFIFO_Req;

             end if;

           when REQST_Quantity  =>

             if usTlp_RE = '1' then

               usTlp_RE_i   <= '1';

               usTlp_Req_i  <= '0';

               FSM_REQ_us   <= REQST_Quantity;

             elsif FIFO_Data_Count(C_FIFO_DC_WIDTH downto C_TLP_FLD_WIDTH_OF_LENG)=C_ALL_ZEROS(C_FIFO_DC_WIDTH downto C_TLP_FLD_WIDTH_OF_LENG)

               and FIFO_Data_Count(C_TLP_FLD_WIDTH_OF_LENG-1 downto 0) < usTlp_MWr_Leng(C_TLP_FLD_WIDTH_OF_LENG-1 downto 0)

               then

               usTlp_RE_i   <= '0';

               usTlp_Req_i  <= '0';

               FSM_REQ_us   <= REQST_Quantity;

             else

               usTlp_RE_i   <= '0';

               usTlp_Req_i  <=  not usDMA_Stop

                            and not usDMA_Stop2

                            and not us_FC_stop;

               FSM_REQ_us   <= REQST_FIFO_Req;

             end if;

           when REQST_FIFO_Req  =>

             if FIFO_Data_Count(C_FIFO_DC_WIDTH downto C_TLP_FLD_WIDTH_OF_LENG)=C_ALL_ZEROS(C_FIFO_DC_WIDTH downto C_TLP_FLD_WIDTH_OF_LENG)

               and FIFO_Data_Count(C_TLP_FLD_WIDTH_OF_LENG-1 downto 0) < usTlp_MWr_Leng(C_TLP_FLD_WIDTH_OF_LENG-1 downto 0)

               then

               usTlp_RE_i   <= '0';

               usTlp_Req_i  <= '0';

               FSM_REQ_us   <= REQST_Quantity;