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-rw-r--r--src/tb/tb_fpga_entropy_core.v208
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diff --git a/src/tb/tb_fpga_entropy_core.v b/src/tb/tb_fpga_entropy_core.v
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+//======================================================================
+//
+// tb_fpga_entropy.v
+// -----------------
+// Testbench for the FPGA Entropy generator core.
+//
+//
+// Author: Joachim Strombergson
+// Copyright (c) 2014, Secworks Sweden AB
+// 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
+
+
+module tb_fpga_entropy();
+
+ //----------------------------------------------------------------
+ // Internal constant and parameter definitions.
+ //----------------------------------------------------------------
+ parameter DEBUG = 1;
+ parameter VERBOSE = 0;
+
+ parameter CLK_HALF_PERIOD = 1;
+ parameter CLK_PERIOD = CLK_HALF_PERIOD * 2;
+
+
+ //----------------------------------------------------------------
+ // 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_update;
+ reg tb_seed;
+ wire [31 : 0] tb_rnd;
+
+
+ //----------------------------------------------------------------
+ // Device Under Test.
+ //----------------------------------------------------------------
+ fpga_entropy_core dut(
+ // Clock and reset.
+ .clk(),
+ .reset_n(),
+
+ .init(tb_init),
+ .update(tb_update),
+ .seed(tb_seed),
+
+ .rnd(tb_rnd)
+ );
+
+
+ //----------------------------------------------------------------
+ // clk_gen
+ //
+ // Clock generator process.
+ //----------------------------------------------------------------
+ always
+ begin : clk_gen
+ #CLK_HALF_PERIOD tb_clk = !tb_clk;
+ end // clk_gen
+
+
+ //----------------------------------------------------------------
+ // sys_monitor
+ //
+ // System monitor. Can display status about the dut and TB
+ // every cycle.
+ //----------------------------------------------------------------
+ always
+ begin : sys_monitor
+ #(CLK_PERIOD);
+ if (DEBUG)
+ begin
+ dump_dut_state();
+ $display("");
+ end
+
+ if (VERBOSE)
+ begin
+ $display("cycle: 0x%016x", cycle_ctr);
+ end
+ cycle_ctr = cycle_ctr + 1;
+ end
+
+
+ //----------------------------------------------------------------
+ // dump_dut_state()
+ //
+ // Dump the state of the dut when needed.
+ //----------------------------------------------------------------
+ task dump_dut_state();
+ begin
+ $display("State of DUT");
+ $display("------------");
+ $display("Inputs and outputs:");
+ $display("init = 0x%01x, update = 0x%01x, seed = 0x%01x",
+ tb_init, tb_update, tb_seed);
+ $display("rnd= 0x%08x", tb_rnd);
+ $display("");
+
+ $display("Internal values:");
+ $display("shift_reg = 0x%08x, rnd_reg = 0x%08x, bit_ctr_reg = 0x%02x",
+ dut.shift_reg, dut.rnd_reg, dut.bit_ctr_reg);
+
+ $display("l5d = 0x%01x, l7d = 0x%01x, l13d = 0x%01x, l41d = 0x01x, l43d = 0x%01x",
+ dut.l5d, dut.l7d, dut.l13d, dut.l41d, dut.l43d);
+ $display("");
+ end
+ endtask // dump_dut_state
+
+
+ //----------------------------------------------------------------
+ // reset_dut()
+ //----------------------------------------------------------------
+ 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 = 1;
+ tb_seed = 1;
+ tb_update = 0;
+ end
+ endtask // init_sim
+
+
+ //----------------------------------------------------------------
+ // fpga_entropy_test
+ //
+ // The main test functionality.
+ //----------------------------------------------------------------
+ initial
+ begin : fpga_entropy_test
+ $display(" -- Testbench for fpga entropy core started --");
+
+ init_sim();
+ dump_dut_state();
+ reset_dut();
+ dump_dut_state();
+
+ tb_update = 1;
+ #(64 * CLK_PERIOD);
+ tb_init = 0;
+ #(1000 * CLK_PERIOD);
+
+ $display("*** Simulation done. ***");
+ $finish;
+ end // fpga_entropy_test
+endmodule // tb_fpga_entropy
+
+//======================================================================
+// EOF tb_fpga_entropy.v
+//======================================================================