// // 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 . // 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; always @(posedge clk) begin if (rst) begin out <= DEFAULT; shadow0 <= DEFAULT; shadow1 <= DEFAULT; end else if (shadow0 == shadow1) begin out <= shadow1; end shadow0 <= in; shadow1 <= shadow0; end endmodule //cross_clock_reader