Subversion Repositories qaz_libs

//

//

//

`timescale 10ps/1ps

module

  cx_encoder

  #(

    parameter CLK_PERIOD      = 320

  )

  (

    output data_out

  );

  // --------------------------------------------------------------------

  //

  wire tx_clock;

  tb_clk #( .CLK_PERIOD(CLK_PERIOD) ) i_tx_clock  ( tx_clock );

  // --------------------------------------------------------------------

  //

  wire tx_clock_10x;

  wire clock_good;

  clock_mult

    #( .MULT(10) )

    tx_clock_10x_i

    (

      .clock_in(tx_clock),

      .clock_out(tx_clock_10x),

      .clock_good(clock_good),

      .reset(1'b0)

    );

  // --------------------------------------------------------------------

  //

  reg [9:0] word_10b[3:0];

  reg       word_10b_out;

  integer   word_10b_index = 0;

  integer   bit_index;

  initial

    begin

      repeat(3)

        @(posedge tx_clock);

      forever

        for( word_10b_index = 0; word_10b_index < 4; word_10b_index = word_10b_index + 1)

          for( bit_index = 0; bit_index < 10; bit_index = bit_index + 1)

            @(negedge tx_clock_10x)

              word_10b_out <= word_10b[word_10b_index][bit_index];

    end

  // --------------------------------------------------------------------

  //

  function automatic [8:0] encode_8b_word;

  input [7:0] word_k;

  input [4:0] word_5b;

  input [2:0] word_3b;

    if( (word_k == "k") | (word_k == "K") )

      encode_8b_word = { 1'b1, word_3b, word_5b };

    else

      encode_8b_word = { 1'b0, word_3b, word_5b };

  endfunction

  localparam K27_7 = encode_8b_word( "K", 27, 7 );  //  K27.7 Start of data packet indication

  localparam K28_0 = encode_8b_word( "K", 28, 0 );  //  K28.0 GPIO indication

  localparam K28_1 = encode_8b_word( "K", 28, 1 );  //  K28.1 Used for alignment

  localparam K28_2 = encode_8b_word( "K", 28, 2 );  //  K28.2 Rising trigger indication

  localparam K28_3 = encode_8b_word( "K", 28, 3 );  //  K28.3 Stream marker – see section 7.2

  localparam K28_4 = encode_8b_word( "K", 28, 4 );  //  K28.4 Falling trigger indication

  localparam K28_5 = encode_8b_word( "K", 28, 5 );  //  K28.5 Used for alignment

  localparam K28_6 = encode_8b_word( "K", 28, 6 );  //  K28.6 I/O acknowledgement

  localparam K28_7 = encode_8b_word( "K", 28, 7 );  //  K29.7 End of data packet indication

  localparam D21_5 = encode_8b_word( "D", 21, 5 );

  // --------------------------------------------------------------------

  //

  reg   [8:0] encode_8b10b_datain_mux   = 0;

  reg         encode_8b10b_dispin       = 0;  // 0 = neg disp; 1 = pos disp

  wire  [9:0] encode_8b10b_dataout_mux;

  wire        encode_8b10b_dispout;

  encode_8b10b

    i_encode_8b10b

    (

      .datain(encode_8b10b_datain_mux),

      .dispin(encode_8b10b_dispin),

      .dataout(encode_8b10b_dataout_mux),

      .dispout(encode_8b10b_dispout)

    );

  // --------------------------------------------------------------------

  //

  reg   [8:0] word_8b[3:0];

  reg         word_8b_we = 0;

  initial

    begin

      word_8b[0] = K28_5;

      word_8b[1] = K28_1;

      word_8b[2] = K28_1;

      word_8b[3] = D21_5;

    end

  always @(posedge tx_clock)

    begin

      encode_8b10b_datain_mux   = word_8b[word_10b_index];

      #1;

      word_8b_we = 1;

      encode_8b10b_dispin       = encode_8b10b_dispout;

      word_10b[word_10b_index]  = encode_8b10b_dataout_mux;

      #1;

      word_8b_we = 0;

    end

  // --------------------------------------------------------------------

  //  debug

`ifdef DEBUG_COAXPRESS

  wire [8:0]  dbg_8b_word =     {

                                  i_encode_8b10b.ai,

                                  i_encode_8b10b.bi,

                                  i_encode_8b10b.ci,

                                  i_encode_8b10b.di,

                                  i_encode_8b10b.ei,

                                  i_encode_8b10b.fi,

                                  i_encode_8b10b.gi,

                                  i_encode_8b10b.hi,

                                  i_encode_8b10b.ki

                                };

  wire [5:0]  dbg_5b_6b_word =  {

                                  i_encode_8b10b.ao,

                                  i_encode_8b10b.bo,

                                  i_encode_8b10b.co,

                                  i_encode_8b10b.do,

                                  i_encode_8b10b.eo,

                                  i_encode_8b10b.io

                                };

  wire [3:0]  dbg_3b_4b_word =  {

                                  i_encode_8b10b.fo,

                                  i_encode_8b10b.go,

                                  i_encode_8b10b.ho,

                                  i_encode_8b10b.jo

                                };

  reg [9:0] dbg_serial_ls;

  reg [9:0] dbg_serial_rs;

  always @(posedge tx_clock_10x)

    begin

      dbg_serial_ls = { dbg_serial_ls[8:0], data_out };

      dbg_serial_rs = { data_out, dbg_serial_rs[9:1] };

    end

  localparam K27_7_10b = 10'b110110_1000;  //  K27.7 Start of data packet indication

  localparam K28_0_10b = 10'b001111_0100;  //  K28.0 GPIO indication

  localparam K28_6_10b = 10'b001111_0110;  //  K28.6 I/O acknowledgement

  localparam K28_1_10b = 10'b001111_1001;  //  K28.1 Used for alignment

  localparam K28_2_10b = 10'b001111_0101;  //  K28.2 Rising trigger indication

  localparam K28_3_10b = 10'b001111_0011;  //  K28.3 Stream marker – see section 7.2

  localparam K28_4_10b = 10'b001111_0010;  //  K28.4 Falling trigger indication

  localparam K28_5_10b = 10'b001111_1010;  //  K28.5 Used for alignment

  localparam K28_7_10b = 10'b001111_1000;  //  K29.7 End of data packet indication

  localparam D21_5_10b = 10'b101010_1010;

  wire dbg_K28_5_10b_is_ls = (dbg_serial_ls == K28_5_10b) | (dbg_serial_ls == ~K28_5_10b);

  wire dbg_K28_1_10b_is_ls = (dbg_serial_ls == K28_1_10b) | (dbg_serial_ls == ~K28_1_10b);

  wire dbg_D21_5_10b_is_ls = (dbg_serial_ls == D21_5_10b) | (dbg_serial_ls == ~D21_5_10b);

  wire dbg_K28_5_10b_is_rs = (dbg_serial_rs == K28_5_10b) | (dbg_serial_rs == ~K28_5_10b);

  wire dbg_K28_1_10b_is_rs = (dbg_serial_rs == K28_1_10b) | (dbg_serial_rs == ~K28_1_10b);

  wire dbg_D21_5_10b_is_rs = (dbg_serial_rs == D21_5_10b) | (dbg_serial_rs == ~D21_5_10b);

`endif

  // --------------------------------------------------------------------

  //

  assign data_out = word_10b_out;

endmodule