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Diffstat (limited to 'src/tb')
| -rw-r--r-- | src/tb/tb_fpga_entropy_core.v | 208 |
1 files changed, 208 insertions, 0 deletions
diff --git a/src/tb/tb_fpga_entropy_core.v b/src/tb/tb_fpga_entropy_core.v new file mode 100644 index 0000000..31696b8 --- /dev/null +++ b/src/tb/tb_fpga_entropy_core.v @@ -0,0 +1,208 @@ +//====================================================================== +// +// 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 +//====================================================================== |