//======================================================================
//
// tb_sha256.v
// -----------
// Testbench for the SHA-256 top level wrapper.
//
//
// Author: Joachim Strombergson
// Copyright (c) 2014, SUNET
// All rights reserved.
//
// 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;
parameter CLK_PERIOD = 2 * CLK_HALF_PERIOD;
// 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_we;
reg [7 : 0] tb_address;
reg [31 : 0] tb_write_data;
wire [31 : 0] tb_read_data;
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),
.we(tb_we),
.address(tb_address),
.write_data(tb_write_data),
.read_data(tb_read_data),
.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, we = 0x%01x",
dut.cs, dut.we);
$display("address = 0x%02x", dut.address);
$display("write_data = 0x%08x, read_data = 0x%08x",
dut.write_data, dut.read_data);
$display("tmp_read_data = 0x%08x", dut.tmp_read_data);
$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_we = 0;
tb_address = 6'h00;
tb_write_data = 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_write_data = word;
tb_cs = 1;
tb_we = 1;
#(CLK_PERIOD);
tb_cs = 0;
tb_we = 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_we = 0;
#(CLK_PERIOD);
read_data = tb_read_data;
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(input [511 : 0] block,
input [255 : 0] expected);
begin
$display("*** TC%01d - Single block test started.", tc_ctr);
write_block(block);
write_word(ADDR_CTRL, CTRL_INIT_VALUE);
#(CLK_PERIOD);
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(input [511 : 0] block0,
input [255 : 0] expected0,
input [511 : 0] block1,
input [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);
#(CLK_PERIOD);
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);
#(CLK_PERIOD);
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
//======================================================================
