Subversion Repositories dvb_s2_ldpc_decoder

`include "Codeword.sv"

`timescale 1ns/10ps

module tb_ldpc();

localparam CLK_PERIOD = 5ns;

localparam HOLD       = 1ns;

localparam SYMS_PER_EBN0 = 10;

localparam EBN0_MIN      = 3.8;

localparam EBN0_MAX      = 4.0;

localparam EBN0_STEP     = 0.2;

localparam CODE_TYPE     = "1_2";

localparam LLRWIDTH = 6;

//////////

// Clocks

//////////

logic clk;

logic rst;

initial

begin

  clk <= 1'b0;

  forever

    #(CLK_PERIOD /2) clk <= ~clk;

end

initial

begin

  rst <= 1'b1;

  repeat(3) @(posedge clk);

  rst <= #HOLD 1'b0;

end

/////////////

// Generator

/////////////

int    packet_number;

int    debug_level;

int    log_level;

string logfilename;

string name;

/* VCS doesn't support parameterized mailboxes, just use one Codeword

   throughout the testbench and one big initial block instead.

Codeword datapath_orig;

Codeword checkpath_orig;

mailbox #(Codeword) data_source;

mailbox #(Codeword) check_source;

semaphore check;

*/

Codeword  check_word;

//////////////

// Transactors

//////////////

// Load data into LLR

// LLR I/O

logic      llr_access;

logic[7:0] llr_addr;

logic      llr_din_we;

logic[360*LLRWIDTH-1:0]      llr_din;

bit signed[360*LLRWIDTH-1:0] llr_dout;

// start command; completion indicator

logic      start;

logic[4:0] mode;

logic[5:0] iter_limit;

bit        done;

localparam READ_LATENCY = 5;

initial

begin

  packet_number = 0;

  debug_level   = 0;

  log_level     = 1;

  logfilename   = "test_testbench.txt";

  name          = "CodewordSpecial";

  check_word = new( CODE_TYPE, debug_level, log_level, logfilename, packet_number, name );

  llr_access  <= 0;

  llr_addr    <= 0;

  llr_din_we  <= 0;

  llr_din     <= 0;

  start       <= 0;

  mode        <= 0;

  iter_limit  <= 20;

  @( posedge rst );

  repeat( 5 ) @( posedge clk );

  for( real ebn0dB=EBN0_MIN; ebn0dB<EBN0_MAX; ebn0dB+=EBN0_STEP )

    for( int symnum=0; symnum<SYMS_PER_EBN0; symnum++ )

    begin

      // create word

      check_word.create_random_msg();

      check_word.encode();

      check_word.AddNoise( ebn0dB );

      check_word.QuantizeLlr( LLRWIDTH );

      // begin testing DUT

      @(posedge clk);

      // write normal data bits

      for( int i=0; i<check_word.GetK()/360; i++ )

      begin

        int wr_val;

        int abs_wr_val;

        llr_addr   <= i;

        llr_access <= 1;

        for( int j=0; j<360; j++ )

        begin

          wr_val = check_word.GetVal(360*i +j);

          //wr_val = 360*i +j;

          abs_wr_val = wr_val < 0 ? -1*wr_val : wr_val;

          llr_din[(j+1)*LLRWIDTH-1 -: LLRWIDTH]

            <= (wr_val<0) ? { 1'b1, abs_wr_val[LLRWIDTH-2:0] }

                          : { 1'b0, abs_wr_val[LLRWIDTH-2:0] };

        end

        llr_din_we <= 1;

        @( posedge clk );

      end

      // write parity bits

      for( int i=0; i<(check_word.GetN()-check_word.GetK())/360; i++ )

      begin

        int rotate_pos;

        int wr_val;

        int abs_wr_val;

        llr_addr <= check_word.GetK()/360 + i;

        for( int j=0; j<360; j++ )

        begin

          rotate_pos = check_word.GetK() + i + j*check_word.GetQ();

          wr_val     = check_word.GetVal(rotate_pos);

          //wr_val     = rotate_pos;

          abs_wr_val = wr_val < 0 ? -1*wr_val : wr_val;

          llr_din[j*LLRWIDTH+LLRWIDTH-1 -: LLRWIDTH]

            <= (wr_val<0) ? { 1'b1, abs_wr_val[LLRWIDTH-2:0] }

                          : { 1'b0, abs_wr_val[LLRWIDTH-2:0] };

        end

        llr_din_we <= 1;

        @( posedge clk );

      end

      llr_din_we <= 0;

      llr_access <= 0;

      @( posedge clk );

      //controls

      start <= 1;

      case( CODE_TYPE )

        "1_4":    mode <= 0;

        "1_3":    mode <= 1;

        "2_5":    mode <= 2;

        "1_2":    mode <= 3;

        "3_5":    mode <= 4;

        "2_3":    mode <= 5;

        "3_4":    mode <= 6;

        "4_5":    mode <= 7;

        "5_6":    mode <= 8;

        "8_9":    mode <= 9;

        "9_10":   mode <= 10;

        "1_5s":   mode <= 11;

        "1_3s":   mode <= 12;

        "2_5s":   mode <= 13;

        "4_9s":   mode <= 14;

        "3_5s":   mode <= 15;

        "2_3s":   mode <= 16;

        "11_15s": mode <= 17;

        "7_9s":   mode <= 18;

        "37_45s": mode <= 19;

        "8_9s":   mode <= 20;

        default: $stop( "Illegal code type!" );

      endcase

      @( posedge clk );

      start <= 0;

      @( posedge clk );

      // read data out

      @(posedge done);

      @(posedge clk);

      llr_access <= 1;

      llr_addr   <= 0;

      @(posedge clk);

      // read normal data bits

      for( int i=0; i<(check_word.GetK()/360)+READ_LATENCY; i++ )

      begin

        int result;

        llr_addr <= i;

        llr_din  <= { LLRWIDTH{1'bX} };

        @( posedge clk );

        if( i>=READ_LATENCY )

          for( int j=0; j<360; j++ )

          begin

            result = llr_dout[j*LLRWIDTH+LLRWIDTH-1]

              ? -1 * { 1'b0, llr_dout[j*LLRWIDTH+LLRWIDTH-2 -: LLRWIDTH-1] }

              : { 1'b0, llr_dout[j*LLRWIDTH+LLRWIDTH-2 -: LLRWIDTH-1] };

            check_word.SetDecoded( 360*(i-READ_LATENCY) +j, result );

          end

      end

      // read parity bits

      for( int i=0; i<((check_word.GetN()-check_word.GetK())/360)+READ_LATENCY; i++ )

      begin

        int result;

        int rotate_pos;

        llr_addr <= check_word.GetK()/360 + i;

        @(posedge clk);

        if( i>=READ_LATENCY )

          for( int j=0; j<360; j++ )

          begin

            rotate_pos = check_word.GetK() + i-READ_LATENCY + j*check_word.GetQ();

            result = llr_dout[j*LLRWIDTH+LLRWIDTH-1]

              ? -1 * { 1'b0, llr_dout[j*LLRWIDTH+LLRWIDTH-2 -: LLRWIDTH-1] }

              : { 1'b0, llr_dout[j*LLRWIDTH+LLRWIDTH-2 -: LLRWIDTH-1] };

            check_word.SetDecoded( rotate_pos, result );

          end

      end

      llr_access <= 0;

      @( posedge clk );

      $display( "EbN0 = %0fdB", ebn0dB );

      $display( "Orig had    %0d errors", check_word.CountOrigErrs() );

      $display( "Decoded had %0d errors", check_word.CountDecodedErrs() );

      check_word.inc(); // increment packet number

    end

  check_word.delete();

  $stop();

end

///////////

// Checker

///////////

////////////

// Instance

////////////

ldp_top #(

  .FOLDFACTOR  (1),

  .NUMINSTANCES(360),

  .LLRWIDTH    (LLRWIDTH)

) ldp_top_i(

  .clk(clk),

  .rst(rst),

  .llr_access (llr_access),

  .llr_addr   (llr_addr),

  .llr_din_we (llr_din_we),

  .llr_din    (llr_din),

  .llr_dout   (llr_dout),

  .start     (start),

  .mode      (mode),

  .iter_limit(iter_limit),

  .done      (done)

);

endmodule