--- /dev/null
+//////////////////////////////////////////////////////////////////////
+//// ////
+//// File name "perr_en_crit.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) 2000 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: pci_perr_en_crit.v,v $
+// Revision 1.1 2007-03-20 17:50:56 sithglan
+// add shit
+//
+// Revision 1.2 2003/02/13 18:26:33 mihad
+// Cleaned up the code. No functional changes.
+//
+// Revision 1.1 2003/01/27 16:49:31 mihad
+// Changed module and file names. Updated scripts accordingly. FIFO synchronizations changed.
+//
+// Revision 1.3 2002/02/01 15:25:13 mihad
+// Repaired a few bugs, updated specification, added test bench files and design document
+//
+// Revision 1.2 2001/10/05 08:14:30 mihad
+// Updated all files with inclusion of timescale file for simulation purposes.
+//
+// Revision 1.1.1.1 2001/10/02 15:33:47 mihad
+// New project directory structure
+//
+//
+
+// module is used to separate logic which uses criticaly constrained inputs from slower logic.
+// It is used to synthesize critical timing logic separately with faster cells or without optimization
+
+// This one is used in parity generator/checker for parity error (PERR#) output enable driving
+
+// synopsys translate_off
+`include "timescale.v"
+// synopsys translate_on
+
+module pci_perr_en_crit
+(
+ reset_in,
+ clk_in,
+ perr_en_out,
+ perr_en_reg_out,
+ non_critical_par_in,
+ pci_par_in,
+ perr_generate_in,
+ par_err_response_in
+) ;
+output perr_en_out,
+ perr_en_reg_out ;
+
+input reset_in,
+ clk_in,
+ non_critical_par_in,
+ pci_par_in,
+ perr_generate_in,
+ par_err_response_in ;
+
+wire perr = par_err_response_in && perr_generate_in && ( non_critical_par_in ^ pci_par_in ) ;
+
+// PERR# is enabled for two clocks after parity error is detected - one cycle active, another inactive
+reg perr_en_reg_out ;
+always@(posedge reset_in or posedge clk_in)
+begin
+ if ( reset_in )
+ perr_en_reg_out <= #1 1'b0 ;
+ else
+ perr_en_reg_out <= #1 perr ;
+end
+
+assign perr_en_out = perr || perr_en_reg_out ;
+
+endmodule