diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/rtl/vndecorrelator.v | 165 | ||||
| -rw-r--r-- | src/tb/tb_vndecorrelator.v | 273 |
2 files changed, 438 insertions, 0 deletions
diff --git a/src/rtl/vndecorrelator.v b/src/rtl/vndecorrelator.v new file mode 100644 index 0000000..57aabfb --- /dev/null +++ b/src/rtl/vndecorrelator.v @@ -0,0 +1,165 @@ +//====================================================================== +// +// vndecorrelator.v +// ---------------- +// von Neumann decorrelator for bits. The module consumes bits +// and for every two bits consume will either emit zero or one bits. +// +// +// Author: Joachim Strömbergson +// Copyright (c) 2019, 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. +// +//====================================================================== + +module vndecorrelator( + input wire clk, + input wire reset_n, + + input wire data_in, + input wire syn_in, + + output wire data_out, + output wire syn_out + ); + + + //---------------------------------------------------------------- + // Internal constant and parameter definitions. + //---------------------------------------------------------------- + parameter CTRL_IDLE = 1'b0; + parameter CTRL_BITS = 1'b1; + + + //---------------------------------------------------------------- + // Registers including update variables and write enable. + //---------------------------------------------------------------- + reg data_in_reg; + reg data_in_we; + + reg data_out_reg; + reg data_out_we; + + reg syn_out_reg; + reg syn_out_new; + + reg vndecorr_ctrl_reg; + reg vndecorr_ctrl_new; + reg vndecorr_ctrl_we; + + + //---------------------------------------------------------------- + // Concurrent connectivity for ports etc. + //---------------------------------------------------------------- + assign data_out = data_out_reg; + assign syn_out = syn_out_reg; + + + //---------------------------------------------------------------- + // reg_update + //---------------------------------------------------------------- + always @ (posedge clk or negedge reset_n) + begin + if (!reset_n) + begin + data_in_reg <= 1'b0; + data_out_reg <= 1'b0; + syn_out_reg <= 1'b0; + vndecorr_ctrl_reg <= CTRL_IDLE; + end + else + begin + syn_out_reg <= syn_out_new; + + if (data_in_we) + begin + data_in_reg <= data_in; + end + + if (data_out_we) + begin + data_out_reg <= data_in; + end + + if (vndecorr_ctrl_we) + begin + vndecorr_ctrl_reg <= vndecorr_ctrl_new; + end + end + end // reg_update + + + //---------------------------------------------------------------- + // vndecorr_logic + // + // The logic implementing the von Neumann decorrelator by waiting + // for subsequent bits and comparing them to determine if both + // bits should just be discarded or one of them also emitted. + //---------------------------------------------------------------- + always @* + begin : vndecorr_logic + data_in_we = 1'b0; + data_out_we = 1'b0; + syn_out_new = 1'b0; + vndecorr_ctrl_new = CTRL_IDLE; + vndecorr_ctrl_we = 1'b0; + + case (vndecorr_ctrl_reg) + CTRL_IDLE: + begin + if (syn_in) + begin + data_in_we = 1'b1; + vndecorr_ctrl_new = CTRL_BITS; + vndecorr_ctrl_we = 1'b1; + end + end + + CTRL_BITS: + begin + if (syn_in) + begin + if (data_in != data_in_reg) + begin + data_out_we = 1'b1; + syn_out_new = 1'b1; + end + + vndecorr_ctrl_new = CTRL_IDLE; + vndecorr_ctrl_we = 1'b1; + end + end + endcase // case (vndecorr_ctrl_reg) + end // vndecorr_logic + +endmodule // vndecorrelator + +//====================================================================== +// EOF vndecorrelator.v +//====================================================================== diff --git a/src/tb/tb_vndecorrelator.v b/src/tb/tb_vndecorrelator.v new file mode 100644 index 0000000..9afe843 --- /dev/null +++ b/src/tb/tb_vndecorrelator.v @@ -0,0 +1,273 @@ +//====================================================================== +// +// tb_vndecorrelator.v +// ------------------- +// Testbench for the von Neumann decorrelator. +// +// +// Author: Joachim Strömbergson +// Copyright (c) 2019, 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_vndecorrelator(); + + + //---------------------------------------------------------------- + // Internal constant and parameter definitions. + //---------------------------------------------------------------- + parameter DEBUG = 1; + + parameter CLK_HALF_PERIOD = 1; + parameter CLK_PERIOD = 2 * CLK_HALF_PERIOD; + + + //---------------------------------------------------------------- + // 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_data_in; + reg tb_syn_in; + wire tb_data_out; + wire tb_syn_out; + + + //---------------------------------------------------------------- + // Device Under Test. + //---------------------------------------------------------------- + vndecorrelator dut( + .clk(tb_clk), + .reset_n(tb_reset_n), + + .data_in(tb_data_in), + .syn_in(tb_syn_in), + + .data_out(tb_data_out), + .syn_out(tb_syn_out) + ); + + + //---------------------------------------------------------------- + // clk_gen + // + // Always running clock generator process. + //---------------------------------------------------------------- + always + begin : clk_gen + #CLK_HALF_PERIOD; + tb_clk = !tb_clk; + end // clk_gen + + + //-------------------------------------------------------------------- + // dut_monitor + // + // Monitor displaying information every cycle. + // Includes the cycle counter. + //-------------------------------------------------------------------- + always @ (posedge tb_clk) + begin : dut_monitor + cycle_ctr = cycle_ctr + 1; + + if (DEBUG) + begin + $display("cycle = %016x:", cycle_ctr); + $display("reset_n = 0x%01x", dut.reset_n); + $display("data_in = 0x%01x, syn_in = 0x%01x", dut.data_in, dut.syn_in); + $display("data_out = 0x%01x, syn_out = 0x%01x", dut.data_out, dut.syn_out); + $display("ctrl = 0x%01x", dut.vndecorr_ctrl_reg); + $display(""); + end + end // dut_monitor + + + //---------------------------------------------------------------- + // 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_data_in = 0; + tb_syn_in = 0; + end + endtask // init_sim + + + //---------------------------------------------------------------- + // decorrelation_test + // + // The main test functionality. + //---------------------------------------------------------------- + initial + begin : decorrelation_test + $display(" -= Testbench for the vpn Neumann decorrelator =-"); + $display(" ==============================================="); + $display(""); + + init_sim(); + reset_dut(); + + // TC1: 1, 0 directly after eachother. Should emit 0. + #(10 *CLK_PERIOD); + $display("TC1: 1 directly followed by 0. Should emit 0."); + tb_data_in = 1; + tb_syn_in = 1; + #(CLK_PERIOD); + tb_data_in = 0; + tb_syn_in = 1; + #(CLK_PERIOD); + tb_syn_in = 0; + + // TC2: 0, 1 directly after eachother. Should generate 1. + #(10 *CLK_PERIOD); + $display("TC2: 0 directly followed by 1. Should emit 1."); + tb_data_in = 0; + tb_syn_in = 1; + #(CLK_PERIOD); + tb_data_in = 1; + tb_syn_in = 1; + #(CLK_PERIOD); + tb_syn_in = 0; + + // TC3: 0, 0 directly after eachother. Should emit nothing. + #(10 *CLK_PERIOD); + $display("TC3: 0 directly followed by 0. Should emit nothing."); + tb_data_in = 0; + tb_syn_in = 1; + #(CLK_PERIOD); + tb_data_in = 0; + tb_syn_in = 1; + #(CLK_PERIOD); + tb_syn_in = 0; + + // TC4: 1, 1 directly after eachother. Should enmit nothing. + #(10 *CLK_PERIOD); + $display("TC4: 1 directly followed by 1. Should emit nothing."); + tb_data_in = 1; + tb_syn_in = 1; + #(CLK_PERIOD); + tb_data_in = 1; + tb_syn_in = 1; + #(CLK_PERIOD); + tb_syn_in = 0; + + // TC5: 1, 0 with 10 cycles in between. Should emit 0. + #(10 *CLK_PERIOD); + $display("TC5: 1 and later 0. Should emit 0."); + tb_data_in = 1; + tb_syn_in = 1; + #(CLK_PERIOD); + tb_syn_in = 0; + #(10 *CLK_PERIOD); + tb_data_in = 0; + tb_syn_in = 1; + #(CLK_PERIOD); + tb_syn_in = 0; + + // TC6: 0, 1 with 10 cycles in between. Should emit 1. + #(10 *CLK_PERIOD); + $display("TC6: 0 and later 1. Should emit 1."); + tb_data_in = 0; + tb_syn_in = 1; + #(CLK_PERIOD); + tb_syn_in = 0; + #(10 *CLK_PERIOD); + tb_data_in = 1; + tb_syn_in = 1; + #(CLK_PERIOD); + tb_syn_in = 0; + + // TC7: 0, 0 with 10 cycles in between. Should emit nothing. + #(10 *CLK_PERIOD); + $display("TC7: 0 and later 0. Should emit nothing."); + tb_data_in = 0; + tb_syn_in = 1; + #(CLK_PERIOD); + tb_syn_in = 0; + #(10 *CLK_PERIOD); + tb_data_in = 0; + tb_syn_in = 1; + #(CLK_PERIOD); + tb_syn_in = 0; + + // TC8: 1, 1 with 10 cycles in between. Should emit nothing. + #(10 *CLK_PERIOD); + $display("TC8: 1 and later 1. Should emit nothing."); + tb_data_in = 1; + tb_syn_in = 1; + #(CLK_PERIOD); + tb_syn_in = 0; + #(10 *CLK_PERIOD); + tb_data_in = 1; + tb_syn_in = 1; + #(CLK_PERIOD); + tb_syn_in = 0; + + $display(""); + $display("*** von Neumann decorrelation simulation done. ***"); + $finish; + end // decorrelation_test +endmodule // tb_vndecorrelator + +//====================================================================== +// EOF tb_vndecorrelator.v +//====================================================================== |