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Diffstat (limited to 'src')
| -rw-r--r-- | src/test/single_rosc.v | 122 |
1 files changed, 122 insertions, 0 deletions
diff --git a/src/test/single_rosc.v b/src/test/single_rosc.v new file mode 100644 index 0000000..62ca198 --- /dev/null +++ b/src/test/single_rosc.v @@ -0,0 +1,122 @@ +//====================================================================== +// +// single_rosc.v +// ------------- +// Top level module for testing the digital ring oscillator. This +// module basically instantiates an oscillator with registered inputs +// and outputs to allow synthesis tools to do good placement and +// timing of the oscillator parts. +// +// The module is used to test how the oscillator is mapped to +// resources in different FPGAs, and what happens when the size +// of the oscillator increases. +// idea of using carry chain in adders as inverter by Bernd Paysan. +// +// +// +// 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. +// +//====================================================================== + +module single_rosc + ( + input wire clk, + input wire reset_n, + + input wire we, + + input wire [(WIDTH - 1) : 0] opa, + input wire [(WIDTH - 1) : 0] opb, + + output wire dout + ); + + parameter WIDTH = 3; + + //---------------------------------------------------------------- + // Registers. + //---------------------------------------------------------------- + reg [(WIDTH - 1) : 0] opa_reg; + reg [(WIDTH - 1) : 0] opb_reg; + + reg we_reg; + + reg dout_reg; + + // Ugly in-line Xilinx attribute to preserve the registers. + (* equivalent_register_removal = "no" *) + wire dout_new; + + + //---------------------------------------------------------------- + // Concurrent assignment. + //---------------------------------------------------------------- + assign dout = dout_reg; + + + //---------------------------------------------------------------- + // oscillator instance. + //---------------------------------------------------------------- + rosc #(.WIDTH(WIDTH)) osc( + .clk(clk), + .we(we_reg), + .reset_n(reset_n), + .opa(opa_reg), + .opb(opb_reg), + .dout(dout_new) + ); + + + //---------------------------------------------------------------- + // reg_update + //---------------------------------------------------------------- + always @ (posedge clk or negedge reset_n) + begin + if (!reset_n) + begin + opa_reg <= {WIDTH{1'b0}}; + opb_reg <= {WIDTH{1'b0}}; + we_reg <= 1'b0; + dout_reg <= 1'b0; + end + else + begin + we_reg <= we; + opa_reg <= opa; + opb_reg <= opb; + dout_reg <= dout_new; + end + end + +endmodule // single_rosc + +//====================================================================== +// EOF single_rosc.v +//====================================================================== |