head 1.1; access; symbols; locks; strict; comment @# @; 1.1 date 2008.08.02.14.36.32; author lekernel; state Exp; branches; next ; commitid 1740489470e74567; desc @@ 1.1 log @Added missing files @ text @/* * Yet Another Dynamic Memory Controller * Copyright (C) 2008 Sebastien Bourdeauducq - http://lekernel.net * This file is part of Milkymist. * * Milkymist is free software; you can redistribute it and/or modify it * under the terms of the GNU Library General Public License as published * by the Free Software Foundation; either version 2, 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 * Library General Public License for more details. * * You should have received a copy of the GNU Library General Public * License along with this program; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, * USA. */ /* Flag synchronizer from clock domain 0 to 1 * See http://www.fpga4fun.com/CrossClockDomain.html */ module yadmc_sync( input clk0, input flagi, input clk1, output flago ); /* Turn the flag into a level change */ reg toggle; initial toggle = 1'b0; always @@(posedge clk0) if(flagi) toggle <= ~toggle; /* Synchronize the level change to clk1. * We add a third flip-flop to be able to detect level changes. */ reg [2:0] sync; initial sync = 3'b000; always @@(posedge clk1) sync <= {sync[1:0], toggle}; /* Recreate the flag from the level change into the clk1 domain */ assign flago = sync[2] ^ sync[1]; endmodule @