Subversion Repositories pci

//////////////////////////////////////////////////////////////////////

////                                                              ////

////  File name "out_reg.v"                                       ////

////                                                              ////

////  This file is part of the "PCI bridge" project               ////

////  http://www.opencores.org/cores/pci/                         ////

////                                                              ////

////  Author(s):                                                  ////

////      - Miha Dolenc (mihad@opencores.org)                     ////

////                                                              ////

////  All additional information is avaliable in the README       ////

////  file.                                                       ////

////                                                              ////

////                                                              ////

//////////////////////////////////////////////////////////////////////

////                                                              ////

//// Copyright (C) 2001 Miha Dolenc, mihad@opencores.org          ////

////                                                              ////

//// This source file may be used and distributed without         ////

//// restriction provided that this copyright statement is not    ////

//// removed from the file and that any derivative work contains  ////

//// the original copyright notice and the associated disclaimer. ////

////                                                              ////

//// This source file is free software; you can redistribute it   ////

//// and/or modify it under the terms of the GNU Lesser General   ////

//// Public License as published by the Free Software Foundation; ////

//// either version 2.1 of the License, or (at your option) any   ////

//// later version.                                               ////

////                                                              ////

//// This source 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 Lesser General Public License for more ////

//// details.                                                     ////

////                                                              ////

//// You should have received a copy of the GNU Lesser General    ////

//// Public License along with this source; if not, download it   ////

//// from http://www.opencores.org/lgpl.shtml                     ////

////                                                              ////

//////////////////////////////////////////////////////////////////////

//

// CVS Revision History

//

// $Log: not supported by cvs2svn $

// Revision 1.2  2001/10/05 08:14:28  mihad

// Updated all files with inclusion of timescale file for simulation purposes.

//

// Revision 1.1.1.1  2001/10/02 15:33:46  mihad

// New project directory structure

//

//

`include "pci_constants.v"

// synopsys translate_off

`include "timescale.v"

// synopsys translate_on

// module inferes a single IOB output block as known in FPGA architectures

// It provides data flip flop with clock enable and output enable flip flop with clock enable

// This is tested in Xilinx FPGA - active low output enable

// Check polarity of output enable flip flop for specific architecure.

module OUT_REG

(

    reset_in,

    clk_in,

    dat_en_in,

    en_en_in,

    dat_in,

    en_in,

    en_out,

    dat_out

);

input   reset_in,

        clk_in,

        dat_en_in,

        en_en_in,

        dat_in,

        en_in ;

output dat_out ;

output en_out ;

reg dat_out,

    en_out ;

`ifdef ACTIVE_LOW_OE

wire en = ~en_in ;

`else

`ifdef ACTIVE_HIGH_OE

wire en = en_in ;

`endif

`endif

always@(posedge reset_in or posedge clk_in)

begin

    if ( reset_in )

        dat_out <= #`FF_DELAY 1'b0 ;

    else if ( dat_en_in )

        dat_out <= #`FF_DELAY dat_in ;

end

always@(posedge reset_in or posedge clk_in)

begin

    if ( reset_in )

        `ifdef ACTIVE_LOW_OE

        en_out <= #`FF_DELAY 1'b1 ;

        `else

        `ifdef ACTIVE_HIGH_OE

        en_out <= #`FF_DELAY 1'b0 ;

        `endif

        `endif

    else if ( en_en_in )

        en_out <= #`FF_DELAY en ;

end

endmodule