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//////////////////////////////////////////////////////////////////////
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//// Copyright (C) 2015 Authors and OPENCORES.ORG                 ////
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//////////////////////////////////////////////////////////////////////

module
  riffa_chn_rx
  #(
    N //  data bus width in bytes
  )
  (
    riffa_chnl_if chnl_bus,
    input rx_ready,
    output rx_done,
    output reg [30:0] rx_index,
    output reg rx_last,
    output reg [31:0] rx_len,
    output reg [30:0] rx_off,
    // output rx_data_ren, // shouldn't be here??
    output rd_empty,
    output [(8*N)-1:0] rd_data,
    input rd_en,

    input clk,
    input reset
  );

  // --------------------------------------------------------------------
  //
  riffa_chnl_rx_fsm
    riffa_chnl_rx_fsm_i
    (
      .rx(chnl_bus.rx),
      .rx_data_valid(chnl_bus.rx_data_valid),
      .rx_ack(chnl_bus.rx_ack),
      .*
    );


  // --------------------------------------------------------------------
  //
  always_ff @(posedge clk)
    if(chnl_bus.rx & chnl_bus.rx_ack)
    begin
      rx_last <= chnl_bus.rx_last;
      rx_len <= chnl_bus.rx_len;
      rx_off <= chnl_bus.rx_off;
    end


  // --------------------------------------------------------------------
  //
  wire [(8*N)-1:0] wr_data = chnl_bus.rx_data;
  wire wr_full;
  wire wr_en = chnl_bus.rx_data_ren & chnl_bus.rx_data_valid;

  tiny_sync_fifo #(.W((8*N)))
    tiny_sync_fifo_i(.*);


  // --------------------------------------------------------------------
  //
  always_ff @(posedge clk)
    if(reset | rx_done)
      rx_index = 0;
    else if(rd_en)
      rx_index <= rx_index + (N/4); // increment by 32 bit words


  // --------------------------------------------------------------------
  //
  // assign rx_data_ren = ~wr_full; // shouldn't be here??
  assign chnl_bus.rx_data_ren = ~wr_full;


// --------------------------------------------------------------------
//
endmodule