pci_io_mux_ad_en_crit.v

这是用pci-wishbone核和16450串口核在xilinx的fpga上实现的串口程序

//////////////////////////////////////////////////////////////////////
////                                                              ////
////  File name "pci_io_mux_ad_en_crit.v"                         ////
////                                                              ////
////  This file is part of the "PCI bridge" project               ////
////  http://www.opencores.org/cores/pci/                         ////
////                                                              ////
////  Author(s):                                                  ////
////      - Miha Dolenc ([e-mail])                     ////
////                                                              ////
////  All additional information is avaliable in the README       ////
////  file.                                                       ////
////                                                              ////
////                                                              ////
//////////////////////////////////////////////////////////////////////
////                                                              ////
//// Copyright (C) 2001 Miha Dolenc, [e-mail]          ////
////                                                              ////
//// 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. ////
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//// 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.                                               ////
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//// This source is distributed in the hope that it will be       ////
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//// 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                     ////
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//////////////////////////////////////////////////////////////////////
//
// CVS Revision History
//
// $Log: pci_io_mux_ad_en_crit.v,v $
// Revision 1.2  2003/01/27 16:49:31  mihad
// Changed module and file names. Updated scripts accordingly. FIFO synchronizations changed.
//
// Revision 1.1  2002/02/01 14:43:31  mihad
// *** empty log message ***
//
//

// module provides equation for ad output enables, which uses critical pci bus inputs

// synopsys translate_off
`include "timescale.v"
// synopsys translate_on

// module is provided for ad bus output enable Flip-Flops values
module pci_io_mux_ad_en_crit
(
    ad_en_in,
    pci_frame_in,
    pci_trdy_in,
    pci_stop_in,
    ad_en_out
);
input  ad_en_in,
       pci_frame_in,
       pci_trdy_in,
       pci_stop_in ;
output ad_en_out ;

assign ad_en_out = ad_en_in && ( ~pci_frame_in || (pci_trdy_in && pci_stop_in) ) ;
endmodule