//======================================================================
//
// tb_sha512_core.v
// ----------------
// Testbench for the SHA-512 core.
//
//
// Author: Joachim Strombergson
// Copyright (c) 2014, NORDUnet A/S
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
// - Redistributions of source code must retain the above copyright notice,
//   this list of conditions and the following disclaimer.
//
// - Redistributions in binary form must reproduce the above copyright
//   notice, this list of conditions and the following disclaimer in the
//   documentation and/or other materials provided with the distribution.
//
// - Neither the name of the NORDUnet nor the names of its contributors may
//   be used to endorse or promote products derived from this software
//   without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
// IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
// TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
// PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
// TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
// PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
// LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
// NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
//======================================================================


//------------------------------------------------------------------
// Test module.
//------------------------------------------------------------------
module tb_sha512_core();

  //----------------------------------------------------------------
  // Internal constant and parameter definitions.
  //----------------------------------------------------------------
  parameter DEBUG = 0;

  parameter CLK_PERIOD      = 2;
  parameter CLK_HALF_PERIOD = CLK_PERIOD / 2;

  parameter MODE_SHA_512_224 = 0;
  parameter MODE_SHA_512_256 = 1;
  parameter MODE_SHA_384     = 2;
  parameter MODE_SHA_512     = 3;


  //----------------------------------------------------------------
  // Register and Wire declarations.
  //----------------------------------------------------------------
  reg [31 : 0] cycle_ctr;
  reg [31 : 0] error_ctr;
  reg [31 : 0] tc_ctr;

  reg            tb_clk;
  reg            tb_reset_n;
  reg            tb_init;
  reg            tb_next;
  reg    [1 : 0] tb_mode;
  reg [1023 : 0] tb_block;
  wire           tb_ready;
  wire [511 : 0] tb_digest;
  wire           tb_digest_valid;


  //----------------------------------------------------------------
  // Device Under Test.
  //----------------------------------------------------------------
  sha512_core dut(
                   .clk(tb_clk),
                   .reset_n(tb_reset_n),

                   .init(tb_init),
                   .next(tb_next),
                   .mode(tb_mode),

                   .work_factor(1'b0),
                   .work_factor_num(32'h0),

                   .block(tb_block),

                   .ready(tb_ready),

                   .state_wr_data(32'h0),
                   .state00_we(1'b0),
                   .state01_we(1'b0),
                   .state02_we(1'b0),
                   .state03_we(1'b0),
                   .state04_we(1'b0),
                   .state05_we(1'b0),
                   .state06_we(1'b0),
                   .state07_we(1'b0),
                   .state08_we(1'b0),
                   .state09_we(1'b0),
                   .state10_we(1'b0),
                   .state11_we(1'b0),
                   .state12_we(1'b0),
                   .state13_we(1'b0),
                   .state14_we(1'b0),
                   .state15_we(1'b0),

                   .digest(tb_digest),
                   .digest_valid(tb_digest_valid)
                 );


  //----------------------------------------------------------------
  // clk_gen
  //
  // Always running clock generator process.
  //----------------------------------------------------------------
  always
    begin : clk_gen
      #CLK_HALF_PERIOD;
      tb_clk = !tb_clk;
    end // clk_gen


  //----------------------------------------------------------------
  // sys_monitor()
  //
  // An always running process that creates a cycle counter and
  // conditionally displays information about the DUT.
  //----------------------------------------------------------------
  always
    begin : sys_monitor
      cycle_ctr = cycle_ctr + 1;
      #(CLK_PERIOD);
      if (DEBUG)
        begin
          dump_dut_state();
        end
    end


  //----------------------------------------------------------------
  // dump_dut_state()
  //
  // Dump the state of the dut.
  //----------------------------------------------------------------
  task dump_dut_state;
    begin
      $display("State of DUT");
      $display("------------");
      $display("Inputs and outputs:");
      $display("init   = 0x%01x, next  = 0x%01x. mode = 0x%01x",
               dut.init, dut.next, dut.mode);
      $display("block  = 0x%0128x", dut.block);

      $display("ready  = 0x%01x, valid = 0x%01x",
               dut.ready, dut.digest_valid);
      $display("digest = 0x%064x", dut.digest);
      $display("H0_reg = 0x%08x, H1_reg = 0x%08x, H2_reg = 0x%08x, H3_reg = 0x%08x",
               dut.H0_reg, dut.H1_reg, dut.H2_reg, dut.H3_reg);
      $display("H4_reg = 0x%08x, H5_reg = 0x%08x, H6_reg = 0x%08x, H7_reg = 0x%08x",
               dut.H4_reg, dut.H5_reg, dut.H6_reg, dut.H7_reg);
      $display("");

      $display("Control signals and counter:");
      $display("sha512_ctrl_reg = 0x%02x", dut.sha512_ctrl_reg);
      $display("digest_init     = 0x%01x, digest_update = 0x%01x",
               dut.digest_init, dut.digest_update);
      $display("state_init      = 0x%01x, state_update  = 0x%01x",
               dut.state_init, dut.state_update);
      $display("first_block     = 0x%01x, ready_flag    = 0x%01x, w_init    = 0x%01x",
               dut.first_block, dut.ready_flag, dut.w_init);
      $display("round_ctr_inc       = 0x%01x, round_ctr_rst     = 0x%01x, round_ctr_reg = 0x%02x",
               dut.round_ctr_inc, dut.round_ctr_rst, dut.round_ctr_reg);
      $display("");

      $display("State registers:");
      $display("a_reg = 0x%08x, b_reg = 0x%08x, c_reg = 0x%08x, d_reg = 0x%08x",
               dut.a_reg, dut.b_reg, dut.c_reg, dut.d_reg);
      $display("e_reg = 0x%08x, f_reg = 0x%08x, g_reg = 0x%08x, h_reg = 0x%08x",
               dut.e_reg, dut.f_reg, dut.g_reg, dut.h_reg);
      $display("");
      $display("a_new = 0x%08x, b_new = 0x%08x, c_new = 0x%08x, d_new = 0x%08x",
               dut.a_new, dut.b_new, dut.c_new, dut.d_new);
      $display("e_new = 0x%08x, f_new = 0x%08x, g_new = 0x%08x, h_new = 0x%08x",
               dut.e_new, dut.f_new, dut.g_new, dut.h_new);
      $display("");

      $display("State update values:");
      $display("w  = 0x%08x, k  = 0x%08x", dut.w_data, dut.k_data);
      $display("t1 = 0x%08x, t2 = 0x%08x", dut.t1, dut.t2);
      $display("");
    end
  endtask // dump_dut_state


  //----------------------------------------------------------------
  // dump_dut_wmem()
  //
  // Dump the state of the dut wmem.
  //----------------------------------------------------------------
  task dump_dut_wmem;
    begin
      $display("State of DUT WMEM");
      $display("-----------------");
      $display("W[00] = 0x%016x, W[01] = 0x%016x, W[02] = 0x%016x, W[03] = 0x%016x",
               dut.w_mem_inst.w_mem[00], dut.w_mem_inst.w_mem[01],
               dut.w_mem_inst.w_mem[02], dut.w_mem_inst.w_mem[03]);
      $display("W[04] = 0x%016x, W[05] = 0x%016x, W[06] = 0x%016x, W[07] = 0x%016x",
               dut.w_mem_inst.w_mem[04], dut.w_mem_inst.w_mem[05],
               dut.w_mem_inst.w_mem[06], dut.w_mem_inst.w_mem[07]);
      $display("W[08] = 0x%016x, W[09] = 0x%016x, W[10] = 0x%016x, W[11] = 0x%016x",
               dut.w_mem_inst.w_mem[08], dut.w_mem_inst.w_mem[09],
               dut.w_mem_inst.w_mem[10], dut.w_mem_inst.w_mem[11]);
      $display("W[12] = 0x%016x, W[13] = 0x%016x, W[14] = 0x%016x, W[15] = 0x%016x",
               dut.w_mem_inst.w_mem[12], dut.w_mem_inst.w_mem[13],
               dut.w_mem_inst.w_mem[14], dut.w_mem_inst.w_mem[15]);
      $display("");
    end
  endtask // dump_dut_wmem


  //----------------------------------------------------------------
  // reset_dut()
  //
  // Toggle reset to put the DUT into a well known state.
  //----------------------------------------------------------------
  task reset_dut;
    begin
      $display("*** Toggle reset.");
      tb_reset_n = 0;
      #(2 * CLK_PERIOD);
      tb_reset_n = 1;
    end
  endtask // reset_dut


  //----------------------------------------------------------------
  // init_sim()
  //
  // Initialize all counters and testbed functionality as well
  // as setting the DUT inputs to defined values.
  //----------------------------------------------------------------
  task init_sim;
    begin
      cycle_ctr = 0;
      error_ctr = 0;
      tc_ctr = 0;

      tb_clk = 0;
      tb_reset_n = 1;

      tb_init = 0;
      tb_next = 0;
      tb_next = 2'b00;
      tb_mode = 2'b00;
      tb_block = {32{32'h00000000}};
    end
  endtask // init_dut


  //----------------------------------------------------------------
  // display_test_result()
  //
  // Display the accumulated test results.
  //----------------------------------------------------------------
  task display_test_result;
    begin
      if (error_ctr == 0)
        begin
          $display("*** All %02d test cases completed successfully", tc_ctr);
        end
      else
        begin
          $display("*** %02d test cases did not complete successfully.", error_ctr);
        end
    end
  endtask // display_test_result


  //----------------------------------------------------------------
  // wait_ready()
  //
  // Wait for the ready flag in the dut to be set.
  //
  // Note: It is the callers responsibility to call the function
  // when the dut is actively processing and will in fact at some
  // point set the flag.
  //----------------------------------------------------------------
  task wait_ready;
    begin
      while (!tb_ready)
        begin
          #(2 * CLK_PERIOD);
        end
    end
  endtask // wait_ready


  //----------------------------------------------------------------
  // single_block_test()
  //
  // Run a test case spanning a single data block.
  //----------------------------------------------------------------
  task single_block_test(input [7 : 0]    tc_number,
                         input [1 : 0]    mode,
                         input [1023 : 0] block,
                         input [511 : 0]  expected);
    reg [511 : 0] mask;

   begin
     $display("*** TC %0d single block test case started.", tc_number);
     tc_ctr = tc_ctr + 1;

     tb_block = block;
     tb_mode  = mode;
     tb_init = 1;
     #(2 * CLK_PERIOD);
     tb_init = 0;

     wait_ready();

     case (mode)
       MODE_SHA_512_224:
         begin
           mask = {{7{32'hffffffff}}, {9{32'h00000000}}};
         end

       MODE_SHA_512_256:
         begin
           mask = {{8{32'hffffffff}}, {8{32'h00000000}}};
         end

       MODE_SHA_384:
         begin
           mask = {{12{32'hffffffff}}, {4{32'h00000000}}};
         end

       MODE_SHA_512:
         begin
           mask = {16{32'hffffffff}};
         end
     endcase // case (mode)

     if ((tb_digest & mask) == expected)
       begin
         $display("*** TC %0d successful.", tc_number);
         $display("");
       end
     else
       begin
         $display("*** ERROR: TC %0d NOT successful.", tc_number);
         $display("Expected: 0x%064x", expected);
         $display("Got:      0x%064x", tb_digest);
         $display("");

         error_ctr = error_ctr + 1;
       end
   end
  endtask // single_block_test


  //----------------------------------------------------------------
  // double_block_test()
  //
  // Run a test case spanning two data blocks. We check both
  // intermediate and final digest.
  //----------------------------------------------------------------
  task double_block_test(input [7 : 0]    tc_number,
                         input [1 : 0]    mode,
                         input [1023 : 0] block1,
                         input [1023 : 0] block2,
                         input [511 : 0]  expected1,
                         input [511 : 0]  expected2);

    reg [511 : 0] mask;
    reg [511 : 0] db_digest1;
    reg           db_error;
   begin
     $display("*** TC %0d double block test case started.", tc_number);
     db_error = 0;
     tc_ctr = tc_ctr + 1;

     $display("*** TC %0d first block started.", tc_number);
     tb_mode  = mode;
     tb_block = block1;
     tb_init = 1;
     #(2 * CLK_PERIOD);
     tb_init = 0;
     wait_ready();
     db_digest1 = tb_digest;
     $display("*** TC %0d first block done.", tc_number);

     $display("*** TC %0d second block started.", tc_number);
     tb_block = block2;
     tb_next = 1;
     #(2 * CLK_PERIOD);
     tb_next = 0;
     wait_ready();
     $display("*** TC %0d second block done.", tc_number);

     if (db_digest1 == expected1)
       begin
         $display("*** TC %0d first block successful", tc_number);
         $display("");
       end
     else
       begin
         $display("*** ERROR: TC %0d first block NOT successful", tc_number);
         $display("Expected: 0x%064x", expected1);
         $display("Got:      0x%064x", db_digest1);
         $display("");
         db_error = 1;
       end

     case (mode)
       MODE_SHA_512_224:
         begin
           mask = {{7{32'hffffffff}}, {9{32'h00000000}}};
         end

       MODE_SHA_512_256:
         begin
           mask = {{8{32'hffffffff}}, {8{32'h00000000}}};
         end

       MODE_SHA_384:
         begin
           mask = {{12{32'hffffffff}}, {4{32'h00000000}}};
         end

       MODE_SHA_512:
         begin
           mask = {16{32'hffffffff}};
         end
     endcase // case (mode)

     if ((tb_digest & mask) == expected2)
       begin
         $display("*** TC %0d second block successful", tc_number);
         $display("");
       end
     else
       begin
         $display("*** ERROR: TC %0d second block NOT successful", tc_number);
         $display("Expected: 0x%064x", expected2);
         $display("Got:      0x%064x", tb_digest);
         $display("");
         db_error = 1;
       end

     if (db_error)
       begin
         error_ctr = error_ctr + 1;
       end
   end
  endtask // double_block_test


  //----------------------------------------------------------------
  // sha512_core_test
  // The main test functionality.
  //
  // Test cases taken from:
  // http://csrc.nist.gov/groups/ST/toolkit/documents/Examples/SHA_All.pdf
  //----------------------------------------------------------------
  initial
    begin : sha512_core_test
      reg [1024 : 0] single_block;
      reg [511 : 0]  tc1_expected;
      reg [511 : 0]  tc2_expected;
      reg [511 : 0]  tc3_expected;
      reg [511 : 0]  tc4_expected;

      reg [1024 : 0] double_block_one;
      reg [1024 : 0] double_block_two;
      reg [511 : 0]  tc5_expected;
      reg [511 : 0]  tc6_expected;
      reg [511 : 0]  tc7_expected;
      reg [511 : 0]  tc8_expected;
      reg [511 : 0]  tc9_expected;
      reg [511 : 0]  tc10_expected;
      reg [511 : 0]  tc11_expected;
      reg [511 : 0]  tc12_expected;

      $display("   -- Testbench for sha512 core started --");

      init_sim();
      dump_dut_state();
      reset_dut();
      dump_dut_state();

      // Single block test mesage.
      single_block = 1024'h6162638000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000018;

      // SHA-512 single block digest and test.
      tc1_expected = 512'hDDAF35A193617ABACC417349AE20413112E6FA4E89A97EA20A9EEEE64B55D39A2192992A274FC1A836BA3C23A3FEEBBD454D4423643CE80E2A9AC94FA54CA49F;
      single_block_test(8'h01, MODE_SHA_512, single_block, tc1_expected);

      // SHA-512_224 single block digest and test.
      tc2_expected = {224'h4634270F707B6A54DAAE7530460842E20E37ED265CEEE9A43E8924AA, {9{32'h00000000}}};
      single_block_test(8'h02, MODE_SHA_512_224, single_block, tc2_expected);

      // SHA-512_256 single block digest and test.
      tc3_expected = {256'h53048E2681941EF99B2E29B76B4C7DABE4C2D0C634FC6D46E0E2F13107E7AF23, {8{32'h00000000}}};
      single_block_test(8'h03, MODE_SHA_512_256, single_block, tc3_expected);

      // SHA-384 single block digest and test.
      tc4_expected = {384'hCB00753F45A35E8BB5A03D699AC65007272C32AB0EDED1631A8B605A43FF5BED8086072BA1E7CC2358BAECA134C825A7, {4{32'h00000000}}};
      single_block_test(8'h04, MODE_SHA_384, single_block, tc4_expected);


      // Two block test message.
      double_block_one = 1024'h61626364656667686263646566676869636465666768696A6465666768696A6B65666768696A6B6C666768696A6B6C6D6768696A6B6C6D6E68696A6B6C6D6E6F696A6B6C6D6E6F706A6B6C6D6E6F70716B6C6D6E6F7071726C6D6E6F707172736D6E6F70717273746E6F70717273747580000000000000000000000000000000;
      double_block_two = 1024'h0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000380;

      // SHA-512 two block digests and test.
      tc5_expected = 512'h4319017A2B706E69CD4B05938BAE5E890186BF199F30AA956EF8B71D2F810585D787D6764B20BDA2A26014470973692000EC057F37D14B8E06ADD5B50E671C72;
      tc6_expected = 512'h8E959B75DAE313DA8CF4F72814FC143F8F7779C6EB9F7FA17299AEADB6889018501D289E4900F7E4331B99DEC4B5433AC7D329EEB6DD26545E96E55B874BE909;
      double_block_test(8'h05, MODE_SHA_512, double_block_one, double_block_two, tc5_expected, tc6_expected);

      // SHA-512_224 two block digests and test.
      tc7_expected = 512'h9606CB2DB7823CE75FE35E2674A8F9EF1417ED9E89C412BB54EA29664586108625852563EED495096DEBAAE2F4737FD75319224B135486F8E6C0F55E700C35B3;
      tc8_expected = {224'h23FEC5BB94D60B23308192640B0C453335D664734FE40E7268674AF9, {9{32'h00000000}}};
      double_block_test(8'h06, MODE_SHA_512_224, double_block_one, double_block_two, tc7_expected, tc8_expected);

      // SHA-512_256 two block digests and test.
      tc9_expected = 512'h8DD99EB081311F8BCBBBC42CC7AFB288E8E9408730419D1E953FF7A2B194048DAE24175483C44C7C809B348E8E88E3ECBF2EA614CEED9C5B51807937F11867E1;
      tc10_expected = {256'h3928E184FB8690F840DA3988121D31BE65CB9D3EF83EE6146FEAC861E19B563A, {8{32'h00000000}}};
      double_block_test(8'h07, MODE_SHA_512_256, double_block_one, double_block_two, tc9_expected, tc10_expected);

      // SHA-384 two block digests and test.
      tc11_expected = 512'h2A7F1D895FD58E0BEAAE96D1A673C741015A2173796C1A88F6352CA156ACAFF7C662113E9EBB4D6417B61A85E2CCF0A937EB9A6660FEB5198F2EBE9A81E6A2C5;
      tc12_expected = {384'h09330C33F71147E83D192FC782CD1B4753111B173B3B05D22FA08086E3B0F712FCC7C71A557E2DB966C3E9FA91746039, {4{32'h00000000}}};
      double_block_test(8'h08, MODE_SHA_384, double_block_one, double_block_two, tc11_expected, tc12_expected);


      display_test_result();
      $display("*** Simulation done.");
      $finish;
    end // sha512_core_test
endmodule // tb_sha512_core

//======================================================================
// EOF tb_sha512_core.v
//======================================================================