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diff --git a/lowlevel/generic/subtractor32_generic.v b/lowlevel/generic/subtractor32_generic.v
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+//------------------------------------------------------------------------------
+//
+// subtractor32_generic.v
+// -----------------------------------------------------------------------------
+// Generic 32-bit subtractor.
+//
+// Authors: Pavel Shatov
+//
+// Copyright (c) 2016, NORDUnet A/S
+//
+// 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 subtractor32_generic
+  (
+   input 	  clk,
+   input [31: 0]  a,
+   input [31: 0]  b,
+   output [31: 0] d,
+   input 	  b_in,
+   output 	  b_out
+   );
+
+   //
+   // Difference
+   //
+   reg [32: 0] 	  d_int;
+
+   always @(posedge clk)
+     d_int <= {1'b0, a} - {1'b0, b} - {{32{1'b0}}, b_in};
+
+   //
+   // Output
+   //
+   assign d = d_int[31:0];
+   assign b_out = d_int[32];
+
+endmodule
+
+//------------------------------------------------------------------------------
+// End-of-File
+//------------------------------------------------------------------------------