diff options
author | Joachim Strömbergson <joachim@secworks.se> | 2015-06-23 16:58:45 +0200 |
---|---|---|
committer | Joachim Strömbergson <joachim@secworks.se> | 2015-06-23 16:58:45 +0200 |
commit | feeb054a16bbb3ed6111ac2a165c6266b20750cb (patch) | |
tree | 7fcf40e1c6b397520fa64fc5cc03ccbe6c375004 /src/rtl/adder.v | |
parent | 435b905a9e1ca2d5cc1b6e5d25689773d19dcde4 (diff) |
Changed name of files to reflect that the adder and the shifters are now not specifically working on 32-bit operands. HEADSUP: This breaks builds that use the old file names.
Diffstat (limited to 'src/rtl/adder.v')
-rw-r--r-- | src/rtl/adder.v | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/src/rtl/adder.v b/src/rtl/adder.v new file mode 100644 index 0000000..fa8ed8c --- /dev/null +++ b/src/rtl/adder.v @@ -0,0 +1,64 @@ +//====================================================================== +// +// adder.v +// ------- +// Adder with separate carry in and carry out. Used in the montprod +// amd residue modules of the modexp core. +// +// +// Author: Peter Magnusson, Joachim Strömbergson +// 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 adder #(parameter OPW = 32) + ( + input [(OPW - 1) : 0] a, + input [(OPW - 1) : 0] b, + input carry_in, + + output wire [(OPW - 1) : 0] sum, + output wire carry_out + ); + + reg [(OPW) : 0] adder_result; + + assign sum = adder_result[(OPW - 1) : 0]; + assign carry_out = adder_result[(OPW)]; + + always @* + begin + adder_result = {1'b0, a} + {1'b0, b} + {{OPW{1'b0}}, carry_in}; + end + +endmodule // adder + +//====================================================================== +// EOF adder.v +//====================================================================== |