a2o/dev/verilog/trilib/tri_csa22.v

56 lines
2.0 KiB
Verilog

// © IBM Corp. 2020
// Licensed under the Apache License, Version 2.0 (the "License"), as modified by
// the terms below; you may not use the files in this repository except in
// compliance with the License as modified.
// You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
//
// Modified Terms:
//
// 1) For the purpose of the patent license granted to you in Section 3 of the
// License, the "Work" hereby includes implementations of the work of authorship
// in physical form.
//
// 2) Notwithstanding any terms to the contrary in the License, any licenses
// necessary for implementation of the Work that are available from OpenPOWER
// via the Power ISA End User License Agreement (EULA) are explicitly excluded
// hereunder, and may be obtained from OpenPOWER under the terms and conditions
// of the EULA.
//
// Unless required by applicable law or agreed to in writing, the reference design
// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License
// for the specific language governing permissions and limitations under the License.
//
// Additional rights, including the ability to physically implement a softcore that
// is compliant with the required sections of the Power ISA Specification, are
// available at no cost under the terms of the OpenPOWER Power ISA EULA, which can be
// obtained (along with the Power ISA) here: https://openpowerfoundation.org.
//*****************************************************************************
// Description: XU Population Count
//
//*****************************************************************************
`timescale 1 ns / 1 ns
module tri_csa22(
a,
b,
car,
sum
);
input a;
input b;
output car;
output sum;
wire car_b;
wire sum_b;
assign car_b = (~(a & b));
assign sum_b = (~(car_b & (a | b))); // this is equiv to an xnor
assign car = (~car_b);
assign sum = (~sum_b);
endmodule