cvw/pipelined/src/generic/lzc.sv
2023-01-14 18:56:46 -08:00

39 lines
1.4 KiB
Systemverilog

///////////////////////////////////////////
//
// Written: me@KatherineParry.com
// Modified: 7/5/2022
//
// Purpose: Leading Zero Counter
//
// A component of the CORE-V-WALLY configurable RISC-V project.
//
// Copyright (C) 2021-23 Harvey Mudd College & Oklahoma State University
//
// SPDX-License-Identifier: Apache-2.0 WITH SHL-2.1
//
// Licensed under the Solderpad Hardware License v 2.1 (the “License”); you may not use this file
// except in compliance with the License, or, at your option, the Apache License version 2.0. You
// may obtain a copy of the License at
//
// https://solderpad.org/licenses/SHL-2.1/
//
// Unless required by applicable law or agreed to in writing, any work 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.
////////////////////////////////////////////////////////////////////////////////////////////////
module lzc #(parameter WIDTH = 1) (
input logic [WIDTH-1:0] num, // number to count the leading zeroes of
output logic [$clog2(WIDTH+1)-1:0] ZeroCnt // the number of leading zeroes
);
integer i;
always_comb begin
i = 0;
while (~num[WIDTH-1-i] & (i < WIDTH)) i = i+1; // search for leading one
ZeroCnt = i[$clog2(WIDTH)-1:0];
end
endmodule