diff options
| -rw-r--r-- | src/rtl/rosc_entropy.v | 2 | ||||
| -rw-r--r-- | src/rtl/rosc_entropy_core.v | 57 | ||||
| -rw-r--r-- | toolruns/Makefile | 68 |
3 files changed, 115 insertions, 12 deletions
diff --git a/src/rtl/rosc_entropy.v b/src/rtl/rosc_entropy.v index 0a7e60b..77af1f5 100644 --- a/src/rtl/rosc_entropy.v +++ b/src/rtl/rosc_entropy.v @@ -141,7 +141,7 @@ module rosc_entropy( .clk(clk), .reset_n(reset_n), - .en(enable_reg), + .enable(enable_reg), .opa(op_a_reg), .opb(op_b_reg), diff --git a/src/rtl/rosc_entropy_core.v b/src/rtl/rosc_entropy_core.v index cd70f8a..4a43eb9 100644 --- a/src/rtl/rosc_entropy_core.v +++ b/src/rtl/rosc_entropy_core.v @@ -40,7 +40,7 @@ module rosc_entropy_core( input wire clk, input wire reset_n, - input wire en, + input wire enable, input wire [31 : 0] opa, input wire [31 : 0] opb, @@ -60,6 +60,8 @@ module rosc_entropy_core( //---------------------------------------------------------------- // Parameters. //---------------------------------------------------------------- + // 100000 cycles warmup delay. + localparam WARMUP_CYCLES = 24'h0186a0; localparam ADDER_WIDTH = 1; localparam DEBUG_DELAY = 32'h002c4b40; localparam NUM_SHIFT_BITS = 8'h20; @@ -69,6 +71,11 @@ module rosc_entropy_core( //---------------------------------------------------------------- // Registers including update variables and write enable. //---------------------------------------------------------------- + reg [23 : 0] warmup_cycle_ctr_reg; + reg [23 : 0] warmup_cycle_ctr_new; + reg warmup_cycle_ctr_we; + reg warmup_done; + reg [31 : 0] ent_shift_reg; reg [31 : 0] ent_shift_new; reg ent_shift_we; @@ -117,7 +124,7 @@ module rosc_entropy_core( assign rosc_outputs = rosc_dout; assign raw_entropy = ent_shift_reg; assign entropy_data = entropy_reg; - assign entropy_valid = entropy_valid_reg; + assign entropy_valid = entropy_valid_reg & warmup_done; assign debug = debug_reg; @@ -155,20 +162,24 @@ module rosc_entropy_core( begin if (!reset_n) begin - ent_shift_reg <= 32'h00000000; - entropy_reg <= 32'h00000000; - entropy_valid_reg <= 0; - bit_ctr_reg <= 8'h00; - sample_ctr_reg <= 8'h00; - debug_delay_ctr_reg <= 32'h00000000; - debug_reg <= 8'h00; - debug_update_reg <= 0; + ent_shift_reg <= 32'h00000000; + entropy_reg <= 32'h00000000; + entropy_valid_reg <= 0; + bit_ctr_reg <= 8'h00; + sample_ctr_reg <= 8'h00; + debug_delay_ctr_reg <= 32'h00000000; + warmup_cycle_ctr_reg <= WARMUP_CYCLES; + debug_reg <= 8'h00; + debug_update_reg <= 0; end else begin sample_ctr_reg <= sample_ctr_new; debug_update_reg <= debug_update; + if (warmup_cycle_ctr_we) + warmup_cycle_ctr_reg <= warmup_cycle_ctr_new; + if (ent_shift_we) begin ent_shift_reg <= ent_shift_new; @@ -229,6 +240,30 @@ module rosc_entropy_core( //---------------------------------------------------------------- + // warmup_ctr + // + // Logic for the warmup counter. This counter starts + // decreasing when reset lifts and decreases until reaching zero. + // At zero the counter stops and asserts warmup_done. + //---------------------------------------------------------------- + always @* + begin : warmup_ctr + if (warmup_cycle_ctr_reg == 0) + begin + warmup_cycle_ctr_new = 24'h000000; + warmup_cycle_ctr_we = 0; + warmup_done = 1; + end + else + begin + warmup_cycle_ctr_new = warmup_cycle_ctr_reg - 1'b1; + warmup_cycle_ctr_we = 1; + warmup_done = 0; + end + end + + + //---------------------------------------------------------------- // entropy_out // // Logic that implements the random output control. If we have @@ -289,7 +324,7 @@ module rosc_entropy_core( sample_ctr_new = sample_ctr_reg + 1'b1; - if (en && (sample_ctr_reg == SAMPLE_CLK_CYCLES)) + if (enable && warmup_done && (sample_ctr_reg == SAMPLE_CLK_CYCLES)) begin sample_ctr_new = 8'h00; bit_ctr_inc = 1; diff --git a/toolruns/Makefile b/toolruns/Makefile new file mode 100644 index 0000000..7b613ee --- /dev/null +++ b/toolruns/Makefile @@ -0,0 +1,68 @@ +#=================================================================== +# +# Makefile +# -------- +# Makefile for compiling the building the rosc entropy +# core and and top level simulations. +# +# +# Author: Joachim Strombergson +# Copyright (c) 2015, 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. +# +#=================================================================== + +CORE_SRC=../src/rtl/rosc_entropy_core.v ../src/rtl/rosc.v +TOP_SRC=../src/rtl/rosc_entropy.v + +CC=iverilog +LINT=verilator --lint-only + +all: rosc.sim + + +rosc.sim: $(TOP_SRC) $(CORE_SRC) + $(CC) -o rosc.sim $(TOP_SRC) $(CORE_SRC) + +lint: $(TOP_SRC) $(CORE_SRC) + $(LINT) --top-module rosc_entropy $(TOP_SRC) $(CORE_SRC) + +clean: + rm -f rosc.sim + + +help: + @echo "Build system for simulation of rosc entropy core." + @echo "" + @echo "Supported targets:" + @echo "------------------" + @echo "clean: Delete all built files." + +#=================================================================== +# EOF Makefile +#=================================================================== |