diff options
Diffstat (limited to 'rtl/lowlevel/generic/subtractor32_generic.v')
-rw-r--r-- | rtl/lowlevel/generic/subtractor32_generic.v | 134 |
1 files changed, 67 insertions, 67 deletions
diff --git a/rtl/lowlevel/generic/subtractor32_generic.v b/rtl/lowlevel/generic/subtractor32_generic.v index 46aefe8..5137ace 100644 --- a/rtl/lowlevel/generic/subtractor32_generic.v +++ b/rtl/lowlevel/generic/subtractor32_generic.v @@ -1,67 +1,67 @@ -//------------------------------------------------------------------------------
-//
-// 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
-//------------------------------------------------------------------------------
+//------------------------------------------------------------------------------ +// +// 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 +//------------------------------------------------------------------------------ |