Adding a testbench for the SHA256 top level wrapper.

1 files changed, 554 insertions, 0 deletions

diff --git a/src/tb/tb_sha256.v b/src/tb/tb_sha256.v
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+//======================================================================
+//
+// tb_sha256.v
+// -----------
+// Testbench for the SHA-256 top level wrapper.
+//
+//
+// Author: Joachim Strombergson
+// Copyright (c) 2014, SUNET
+// 
+// Redistribution and use in source and binary forms, with or 
+// without modification, are permitted provided that the following 
+// conditions are met: 
+// 
+// 1. Redistributions of source code must retain the above copyright 
+//    notice, this list of conditions and the following disclaimer. 
+// 
+// 2. 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. 
+// 
+// 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 OWNER 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.
+//
+//======================================================================
+
+//------------------------------------------------------------------
+// Simulator directives.
+//------------------------------------------------------------------
+`timescale 1ns/10ps
+
+
+//------------------------------------------------------------------
+// Test module.
+//------------------------------------------------------------------
+module tb_sha256();
+  
+  //----------------------------------------------------------------
+  // Internal constant and parameter definitions.
+  //----------------------------------------------------------------
+  parameter DEBUG = 0;
+
+  parameter CLK_HALF_PERIOD = 2;
+
+  // The address map.
+  parameter ADDR_NAME0       = 8'h00;
+  parameter ADDR_NAME1       = 8'h01;
+  parameter ADDR_VERSION     = 8'h02;
+
+  parameter ADDR_CTRL        = 8'h08;
+  parameter CTRL_INIT_VALUE  = 8'h01;
+  parameter CTRL_NEXT_VALUE  = 8'h02;
+
+  parameter ADDR_STATUS      = 8'h09;
+  parameter STATUS_READY_BIT = 0;
+  parameter STATUS_VALID_BIT = 1;
+                             
+  parameter ADDR_BLOCK0    = 8'h10;
+  parameter ADDR_BLOCK1    = 8'h11;
+  parameter ADDR_BLOCK2    = 8'h12;
+  parameter ADDR_BLOCK3    = 8'h13;
+  parameter ADDR_BLOCK4    = 8'h14;
+  parameter ADDR_BLOCK5    = 8'h15;
+  parameter ADDR_BLOCK6    = 8'h16;
+  parameter ADDR_BLOCK7    = 8'h17;
+  parameter ADDR_BLOCK8    = 8'h18;
+  parameter ADDR_BLOCK9    = 8'h19;
+  parameter ADDR_BLOCK10   = 8'h1a;
+  parameter ADDR_BLOCK11   = 8'h1b;
+  parameter ADDR_BLOCK12   = 8'h1c;
+  parameter ADDR_BLOCK13   = 8'h1d;
+  parameter ADDR_BLOCK14   = 8'h1e;
+  parameter ADDR_BLOCK15   = 8'h1f;
+                             
+  parameter ADDR_DIGEST0   = 8'h20;
+  parameter ADDR_DIGEST1   = 8'h21;
+  parameter ADDR_DIGEST2   = 8'h22;
+  parameter ADDR_DIGEST3   = 8'h23;
+  parameter ADDR_DIGEST4   = 8'h24;
+  parameter ADDR_DIGEST5   = 8'h25;
+  parameter ADDR_DIGEST6   = 8'h26;
+  parameter ADDR_DIGEST7   = 8'h27;
+
+  
+  //----------------------------------------------------------------
+  // 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_cs;
+  reg           tb_write_read;
+  reg [7 : 0]   tb_address;
+  reg [31 : 0]  tb_data_in;
+  wire [31 : 0] tb_data_out;
+  wire          tb_error;
+
+  reg [31 : 0]  read_data;
+  reg [255 : 0] digest_data;
+  
+  
+  //----------------------------------------------------------------
+  // Device Under Test.
+  //----------------------------------------------------------------
+  sha256 dut(
+             .clk(tb_clk),
+             .reset_n(tb_reset_n),
+             
+             .cs(tb_cs),
+             .write_read(tb_write_read),
+             
+             
+             .address(tb_address),
+             .data_in(tb_data_in),
+             .data_out(tb_data_out),
+             .error(tb_error)
+            );
+  
+
+  //----------------------------------------------------------------
+  // clk_gen
+  //
+  // Clock generator process. 
+  //----------------------------------------------------------------
+  always 
+    begin : clk_gen
+      #CLK_HALF_PERIOD tb_clk = !tb_clk;
+    end // clk_gen
+    
+
+  //----------------------------------------------------------------
+  // sys_monitor
+  //
+  // Generates a cycle counter and displays information about
+  // the dut as needed.
+  //----------------------------------------------------------------
+  always
+    begin : sys_monitor
+      #(2 * CLK_HALF_PERIOD);
+      cycle_ctr = cycle_ctr + 1;
+    end
+
+  
+  //----------------------------------------------------------------
+  // dump_dut_state()
+  //
+  // Dump the state of the dump when needed.
+  //----------------------------------------------------------------
+  task dump_dut_state();
+    begin
+      $display("State of DUT");
+      $display("------------");
+      $display("Inputs and outputs:");
+      $display("cs = 0x%01x, write_read = 0x%01x", 
+               dut.cs, dut.write_read);
+      $display("address = 0x%02x", dut.address);
+      $display("data_in = 0x%08x, data_out = 0x%08x", 
+               dut.data_in, dut.data_out);
+      $display("tmp_data_out = 0x%08x", dut.tmp_data_out);
+      $display("");
+
+      $display("Control and status:");
+      $display("ctrl = 0x%02x, status = 0x%02x", 
+               {dut.next_reg, dut.init_reg}, 
+               {dut.digest_valid_reg, dut.ready_reg});
+      $display("");
+      
+      $display("Message block:");
+      $display("block0  = 0x%08x, block1  = 0x%08x, block2  = 0x%08x,  block3  = 0x%08x",
+               dut.block0_reg, dut.block1_reg, dut.block2_reg, dut.block3_reg);
+      $display("block4  = 0x%08x, block5  = 0x%08x, block6  = 0x%08x,  block7  = 0x%08x",
+               dut.block4_reg, dut.block5_reg, dut.block6_reg, dut.block7_reg);
+
+      $display("block8  = 0x%08x, block9  = 0x%08x, block10 = 0x%08x,  block11 = 0x%08x",
+               dut.block8_reg, dut.block9_reg, dut.block10_reg, dut.block11_reg);
+     $display("block12 = 0x%08x, block13 = 0x%08x, block14 = 0x%08x,  block15 = 0x%08x",
+               dut.block12_reg, dut.block13_reg, dut.block14_reg, dut.block15_reg);
+      $display("");
+      
+      $display("Digest:");
+      $display("digest = 0x%064x", dut.digest_reg);
+      $display("");
+      
+    end
+  endtask // dump_dut_state
+  
+  
+  //----------------------------------------------------------------
+  // reset_dut()
+  //
+  // Toggles reset to force the DUT into a well defined state.
+  //----------------------------------------------------------------
+  task reset_dut();
+    begin
+      $display("*** Toggle reset.");
+      tb_reset_n = 0;
+      #(4 * CLK_HALF_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 = 32'h00000000;
+      error_ctr = 32'h00000000;
+      tc_ctr = 32'h00000000;
+      
+      tb_clk = 0;
+      tb_reset_n = 0;
+      tb_cs = 0;
+      tb_write_read = 0;
+      tb_address = 6'h00;
+      tb_data_in = 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 completed.", tc_ctr);
+          $display("*** %02d errors detected during testing.", error_ctr);
+        end
+    end
+  endtask // display_test_result
+  
+  
+  //----------------------------------------------------------------
+  // wait_ready()
+  //
+  // Wait for the ready flag in the dut to be set.
+  // (Actually we wait for either ready or valid 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
+      read_data = 0;
+      
+      while (read_data == 0)
+        begin
+          read_word(ADDR_STATUS);
+        end
+    end
+  endtask // wait_ready
+  
+
+  //----------------------------------------------------------------
+  // write_word()
+  //
+  // Write the given word to the DUT using the DUT interface.
+  //----------------------------------------------------------------
+  task write_word(input [7 : 0]  address,
+                  input [31 : 0] word);
+    begin
+      if (DEBUG)
+        begin
+          $display("*** Writing 0x%08x to 0x%02x.", word, address);
+          $display("");
+        end
+         
+      tb_address = address;
+      tb_data_in = word;
+      tb_cs = 1;
+      tb_write_read = 1;
+      #(2 * CLK_HALF_PERIOD);
+      tb_cs = 0;
+      tb_write_read = 0;
+    end
+  endtask // write_word
+
+
+  //----------------------------------------------------------------
+  // write_block()
+  //
+  // Write the given block to the dut.
+  //----------------------------------------------------------------
+  task write_block(input [511 : 0] block);
+    begin
+      write_word(ADDR_BLOCK0,  block[511 : 480]);
+      write_word(ADDR_BLOCK1,  block[479 : 448]);
+      write_word(ADDR_BLOCK2,  block[447 : 416]);
+      write_word(ADDR_BLOCK3,  block[415 : 384]);
+      write_word(ADDR_BLOCK4,  block[383 : 352]);
+      write_word(ADDR_BLOCK5,  block[351 : 320]);
+      write_word(ADDR_BLOCK6,  block[319 : 288]);
+      write_word(ADDR_BLOCK7,  block[287 : 256]);
+      write_word(ADDR_BLOCK8,  block[255 : 224]);
+      write_word(ADDR_BLOCK9,  block[223 : 192]);
+      write_word(ADDR_BLOCK10, block[191 : 160]);
+      write_word(ADDR_BLOCK11, block[159 : 128]);
+      write_word(ADDR_BLOCK12, block[127 :  96]);
+      write_word(ADDR_BLOCK13, block[95  :  64]);
+      write_word(ADDR_BLOCK14, block[63  :  32]);
+      write_word(ADDR_BLOCK15, block[31  :   0]);
+    end
+  endtask // write_block
+  
+
+  //----------------------------------------------------------------
+  // read_word()
+  //
+  // Read a data word from the given address in the DUT.
+  // the word read will be available in the global variable
+  // read_data.
+  //----------------------------------------------------------------
+  task read_word(input [7 : 0]  address);
+    begin
+      tb_address = address;
+      tb_cs = 1;
+      tb_write_read = 0;
+      #(2 * CLK_HALF_PERIOD);
+      read_data = tb_data_out;
+      tb_cs = 0;
+
+      if (DEBUG)
+        begin
+          $display("*** Reading 0x%08x from 0x%02x.", read_data, address);
+          $display("");
+        end
+    end
+  endtask // read_word
+
+  
+  //----------------------------------------------------------------
+  // check_name_version()
+  //
+  // Read the name and version from the DUT.
+  //----------------------------------------------------------------
+  task check_name_version();
+    reg [31 : 0] name0;
+    reg [31 : 0] name1;
+    reg [31 : 0] version;
+    begin
+
+      read_word(ADDR_NAME0);
+      name0 = read_data;
+      read_word(ADDR_NAME1);
+      name1 = read_data;
+      read_word(ADDR_VERSION);
+      version = read_data;
+
+      $display("DUT name: %c%c%c%c%c%c%c%c",
+               name0[31 : 24], name0[23 : 16], name0[15 : 8], name0[7 : 0],
+               name1[31 : 24], name1[23 : 16], name1[15 : 8], name1[7 : 0]);
+      $display("DUT version: %c%c%c%c",
+               version[31 : 24], version[23 : 16], version[15 : 8], version[7 : 0]);
+    end
+  endtask // check_name_version
+  
+
+  //----------------------------------------------------------------
+  // read_digest()
+  //
+  // Read the digest in the dut. The resulting digest will be
+  // available in the global variable digest_data.
+  //----------------------------------------------------------------
+  task read_digest();
+    begin
+      read_word(ADDR_DIGEST0);
+      digest_data[255 : 224] = read_data;
+      read_word(ADDR_DIGEST1);
+      digest_data[223 : 192] = read_data;
+      read_word(ADDR_DIGEST2);
+      digest_data[191 : 160] = read_data;
+      read_word(ADDR_DIGEST3);
+      digest_data[159 : 128] = read_data;
+      read_word(ADDR_DIGEST4);
+      digest_data[127 :  96] = read_data;
+      read_word(ADDR_DIGEST5);
+      digest_data[95  :  64] = read_data;
+      read_word(ADDR_DIGEST6);
+      digest_data[63  :  32] = read_data;
+      read_word(ADDR_DIGEST7);
+      digest_data[31  :   0] = read_data;
+    end
+  endtask // read_digest
+    
+  
+  //----------------------------------------------------------------
+  // single_block_test()
+  //
+  //
+  // Perform test of a single block digest.
+  //----------------------------------------------------------------
+  task single_block_test([511 : 0] block,
+                         [255 : 0] expected);
+    begin
+      $display("*** TC%01d - Single block test started.", tc_ctr); 
+     
+      write_block(block);
+      write_word(ADDR_CTRL, CTRL_INIT_VALUE);
+      write_word(ADDR_CTRL, 8'h00);
+      wait_ready();
+      read_digest();
+
+      if (digest_data == expected)
+        begin
+          $display("TC%01d: OK.", tc_ctr);
+        end
+      else
+        begin
+          $display("TC%01d: ERROR.", tc_ctr);
+          $display("TC%01d: Expected: 0x%064x", tc_ctr, expected);
+          $display("TC%01d: Got:      0x%064x", tc_ctr, digest_data);
+          error_ctr = error_ctr + 1;
+        end
+      $display("*** TC%01d - Single block test done.", tc_ctr); 
+      tc_ctr = tc_ctr + 1;
+    end
+  endtask // single_block_test
+    
+  
+  //----------------------------------------------------------------
+  // double_block_test()
+  //
+  //
+  // Perform test of a double block digest. Note that we check
+  // the digests for both the first and final block.
+  //----------------------------------------------------------------
+  task double_block_test([511 : 0] block0,
+                         [255 : 0] expected0,
+                         [511 : 0] block1,
+                         [255 : 0] expected1
+                        );
+    begin
+      $display("*** TC%01d - Double block test started.", tc_ctr); 
+
+      // First block
+      write_block(block0);
+      write_word(ADDR_CTRL, CTRL_INIT_VALUE);
+      write_word(ADDR_CTRL, 8'h00);
+      wait_ready();
+      read_digest();
+
+      if (digest_data == expected0)
+        begin
+          $display("TC%01d first block: OK.", tc_ctr);
+        end
+      else
+        begin
+          $display("TC%01d: ERROR in first digest", tc_ctr);
+          $display("TC%01d: Expected: 0x%064x", tc_ctr, expected0);
+          $display("TC%01d: Got:      0x%064x", tc_ctr, digest_data);
+          error_ctr = error_ctr + 1;
+        end
+
+      // Final block
+      write_block(block1);
+      write_word(ADDR_CTRL, CTRL_NEXT_VALUE);
+      write_word(ADDR_CTRL, 8'h00);
+      wait_ready();
+      read_digest();
+      
+      if (digest_data == expected1)
+        begin
+          $display("TC%01d final block: OK.", tc_ctr);
+        end
+      else
+        begin
+          $display("TC%01d: ERROR in final digest", tc_ctr);
+          $display("TC%01d: Expected: 0x%064x", tc_ctr, expected1);
+          $display("TC%01d: Got:      0x%064x", tc_ctr, digest_data);
+          error_ctr = error_ctr + 1;
+        end
+
+      $display("*** TC%01d - Double block test done.", tc_ctr); 
+      tc_ctr = tc_ctr + 1;
+    end
+  endtask // double_block_test
+
+    
+  //----------------------------------------------------------------
+  // sha256_test
+  // The main test functionality. 
+  //
+  // Test cases taken from:
+  // http://csrc.nist.gov/groups/ST/toolkit/documents/Examples/SHA256.pdf
+  //----------------------------------------------------------------
+  initial
+    begin : sha256_test
+      reg [511 : 0] tc0;
+      reg [255 : 0] res0;
+
+      reg [511 : 0] tc1_0;
+      reg [255 : 0] res1_0;
+      reg [511 : 0] tc1_1;
+      reg [255 : 0] res1_1;
+      
+      $display("   -- Testbench for sha256 started --");
+
+      init_sim();
+      reset_dut();
+      check_name_version();
+
+      // dump_dut_state();
+      // write_word(ADDR_BLOCK0, 32'hdeadbeef);
+      // dump_dut_state();
+      // read_word(ADDR_BLOCK0);
+      // dump_dut_state();
+
+      tc0 = 512'h61626380000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000018;
+      res0 = 256'hBA7816BF8F01CFEA414140DE5DAE2223B00361A396177A9CB410FF61F20015AD;
+      single_block_test(tc0, res0);
+
+      tc1_0 = 512'h6162636462636465636465666465666765666768666768696768696A68696A6B696A6B6C6A6B6C6D6B6C6D6E6C6D6E6F6D6E6F706E6F70718000000000000000;
+      res1_0 = 256'h85E655D6417A17953363376A624CDE5C76E09589CAC5F811CC4B32C1F20E533A;
+      tc1_1 = 512'h000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000001C0;
+      res1_1 = 256'h248D6A61D20638B8E5C026930C3E6039A33CE45964FF2167F6ECEDD419DB06C1;
+      double_block_test(tc1_0, res1_0, tc1_1, res1_1);
+      
+      display_test_result();
+      
+      $display("   -- Testbench for sha256 done. --");
+      $finish;
+    end // sha256_test
+endmodule // tb_sha256
+
+//======================================================================
+// EOF tb_sha256.v
+//======================================================================