125 lines
4.6 KiB
Verilog
125 lines
4.6 KiB
Verilog
//////////////////////////////////////////////////////////////////////
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//// ////
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//// File name "out_reg.v" ////
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//// ////
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//// This file is part of the "PCI bridge" project ////
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//// http://www.opencores.org/cores/pci/ ////
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//// ////
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//// Author(s): ////
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//// - Miha Dolenc (mihad@opencores.org) ////
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//// ////
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//// All additional information is avaliable in the README ////
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//// file. ////
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//// ////
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//// ////
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//////////////////////////////////////////////////////////////////////
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//// ////
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//// Copyright (C) 2001 Miha Dolenc, mihad@opencores.org ////
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//// ////
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//// This source file may be used and distributed without ////
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//// restriction provided that this copyright statement is not ////
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//// removed from the file and that any derivative work contains ////
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//// the original copyright notice and the associated disclaimer. ////
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//// ////
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//// This source file is free software; you can redistribute it ////
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//// and/or modify it under the terms of the GNU Lesser General ////
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//// Public License as published by the Free Software Foundation; ////
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//// either version 2.1 of the License, or (at your option) any ////
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//// later version. ////
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//// ////
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//// This source is distributed in the hope that it will be ////
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//// useful, but WITHOUT ANY WARRANTY; without even the implied ////
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//// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR ////
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//// PURPOSE. See the GNU Lesser General Public License for more ////
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//// details. ////
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//// ////
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//// You should have received a copy of the GNU Lesser General ////
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//// Public License along with this source; if not, download it ////
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//// from http://www.opencores.org/lgpl.shtml ////
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//// ////
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//////////////////////////////////////////////////////////////////////
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//
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// CVS Revision History
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//
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// $Log: pci_out_reg.v,v $
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// Revision 1.1 2003/01/27 16:49:31 mihad
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// Changed module and file names. Updated scripts accordingly. FIFO synchronizations changed.
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//
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// Revision 1.3 2002/02/01 15:25:12 mihad
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// Repaired a few bugs, updated specification, added test bench files and design document
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//
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// Revision 1.2 2001/10/05 08:14:28 mihad
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// Updated all files with inclusion of timescale file for simulation purposes.
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//
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// Revision 1.1.1.1 2001/10/02 15:33:46 mihad
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// New project directory structure
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//
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//
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`include "pci_constants.v"
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// synopsys translate_off
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`include "timescale.v"
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// synopsys translate_on
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// module inferes a single IOB output block as known in FPGA architectures
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// It provides data flip flop with clock enable and output enable flip flop with clock enable
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// This is tested in Xilinx FPGA - active low output enable
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// Check polarity of output enable flip flop for specific architecure.
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module pci_out_reg
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(
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reset_in,
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clk_in,
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dat_en_in,
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en_en_in,
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dat_in,
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en_in,
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en_out,
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dat_out
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);
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input reset_in,
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clk_in,
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dat_en_in,
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en_en_in,
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dat_in,
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en_in ;
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output dat_out ;
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output en_out ;
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reg dat_out,
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en_out ;
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`ifdef ACTIVE_LOW_OE
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wire en = ~en_in ;
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`else
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`ifdef ACTIVE_HIGH_OE
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wire en = en_in ;
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`endif
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`endif
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always@(posedge reset_in or posedge clk_in)
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begin
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if ( reset_in )
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dat_out <= #`FF_DELAY 1'b0 ;
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else if ( dat_en_in )
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dat_out <= #`FF_DELAY dat_in ;
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end
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always@(posedge reset_in or posedge clk_in)
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begin
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if ( reset_in )
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`ifdef ACTIVE_LOW_OE
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en_out <= #`FF_DELAY 1'b1 ;
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`else
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`ifdef ACTIVE_HIGH_OE
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en_out <= #`FF_DELAY 1'b0 ;
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`endif
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`endif
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else if ( en_en_in )
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en_out <= #`FF_DELAY en ;
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end
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endmodule
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