mirror of https://github.com/YosysHQ/yosys.git
81 lines
3.1 KiB
Coq
81 lines
3.1 KiB
Coq
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//----------------------------------------------------------------------------
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// Copyright (C) 2009 , Olivier Girard
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//
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// Redistribution and use in source and binary forms, with or without
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// modification, are permitted provided that the following conditions
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// are met:
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// * Redistributions of source code must retain the above copyright
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// notice, this list of conditions and the following disclaimer.
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// * Redistributions in binary form must reproduce the above copyright
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// notice, this list of conditions and the following disclaimer in the
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// documentation and/or other materials provided with the distribution.
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// * Neither the name of the authors nor the names of its contributors
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// may be used to endorse or promote products derived from this software
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// without specific prior written permission.
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//
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// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
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// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
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// OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
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// THE POSSIBILITY OF SUCH DAMAGE
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//
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//----------------------------------------------------------------------------
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//
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// *File Name: omsp_sync_cell.v
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//
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// *Module Description:
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// Generic synchronizer for the openMSP430
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//
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// *Author(s):
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// - Olivier Girard, olgirard@gmail.com
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//
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//----------------------------------------------------------------------------
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// $Rev: 103 $
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// $LastChangedBy: olivier.girard $
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// $LastChangedDate: 2011-03-05 15:44:48 +0100 (Sat, 05 Mar 2011) $
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//----------------------------------------------------------------------------
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module omsp_sync_cell (
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// OUTPUTs
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data_out, // Synchronized data output
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// INPUTs
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clk, // Receiving clock
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data_in, // Asynchronous data input
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rst // Receiving reset (active high)
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);
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// OUTPUTs
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//=========
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output data_out; // Synchronized data output
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// INPUTs
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//=========
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input clk; // Receiving clock
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input data_in; // Asynchronous data input
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input rst; // Receiving reset (active high)
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//=============================================================================
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// 1) SYNCHRONIZER
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//=============================================================================
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reg [1:0] data_sync;
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always @(posedge clk or posedge rst)
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if (rst) data_sync <= 2'b00;
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else data_sync <= {data_sync[0], data_in};
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assign data_out = data_sync[1];
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endmodule // omsp_sync_cell
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