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//
// Copyright 2011-2012 Ettus Research LLC
//
// 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, or
// (at your option) any later version.
//
// 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 cross_clock_reader
#(
parameter WIDTH = 1,
parameter DEFAULT = 0
)
(
input clk, input rst,
input [WIDTH-1:0] in,
output reg [WIDTH-1:0] out
);
reg [WIDTH-1:0] shadow0, shadow1;
reg [2:0] count;
always @(posedge clk) begin
if (rst) begin
out <= DEFAULT;
shadow0 <= DEFAULT;
shadow1 <= DEFAULT;
count <= 0;
end
else if (shadow0 == shadow1) count <= count + 1;
else count <= 0;
shadow0 <= in;
shadow1 <= shadow0;
if (count == 3'b111) out <= shadow1;
end
endmodule //cross_clock_reader
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