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linguist/samples/Verilog/mux.v
2012-07-23 15:52:49 -05:00

46 lines
1.2 KiB
Verilog
Executable File

`timescale 1ns / 1ps
// Copyright (C) 2008 Schuyler Eldridge, Boston University
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
module mux(opA,opB,sum,dsp_sel,out);
input [3:0] opA,opB;
input [4:0] sum;
input [1:0] dsp_sel;
output [3:0] out;
reg cout;
always @ (sum)
begin
if (sum[4] == 1)
cout <= 4'b0001;
else
cout <= 4'b0000;
end
reg out;
always @(dsp_sel,sum,cout,opB,opA)
begin
if (dsp_sel == 2'b00)
out <= sum[3:0];
else if (dsp_sel == 2'b01)
out <= cout;
else if (dsp_sel == 2'b10)
out <= opB;
else if (dsp_sel == 2'b11)
out <= opA;
end
endmodule