pci_io_mux.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.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. ////
////                                                              ////
//// 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_io_mux.v,v $
// Revision 1.5  2003/12/19 11:11:30  mihad
// Compact PCI Hot Swap support added.
// New testcases added.
// Specification updated.
// Test application changed to support WB B3 cycles.
//
// Revision 1.4  2003/01/27 16:49:31  mihad
// Changed module and file names. Updated scripts accordingly. FIFO synchronizations changed.
//
// Revision 1.3  2002/02/01 15:25:12  mihad
// Repaired a few bugs, updated specification, added test bench files and design document
//
// Revision 1.2  2001/10/05 08:14:29  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
//
//

// this module instantiates output flip flops for PCI interface and
// some fanout downsizing logic because of heavily constrained PCI signals

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

module pci_io_mux
(
    reset_in,
    clk_in,
    frame_in,
    frame_en_in,
    frame_load_in,
    irdy_in,
    irdy_en_in,
    devsel_in,
    devsel_en_in,
    trdy_in,
    trdy_en_in,
    stop_in,
    stop_en_in,
    master_load_in,
    master_load_on_transfer_in,
    target_load_in,
    target_load_on_transfer_in,
    cbe_in,
    cbe_en_in,
    mas_ad_in,
    tar_ad_in,

    par_in,
    par_en_in,
    perr_in,
    perr_en_in,
    serr_in,
    serr_en_in,

    req_in,

    mas_ad_en_in,
    tar_ad_en_in,
    tar_ad_en_reg_in,

    ad_en_out,
    frame_en_out,
    irdy_en_out,
    devsel_en_out,
    trdy_en_out,
    stop_en_out,
    cbe_en_out,

    frame_out,
    irdy_out,
    devsel_out,
    trdy_out,
    stop_out,
    cbe_out,
    ad_out,
    ad_load_out,
    ad_en_unregistered_out,

    par_out,
    par_en_out,
    perr_out,
    perr_en_out,
    serr_out,
    serr_en_out,

    req_out,
    req_en_out,
    pci_trdy_in,
    pci_irdy_in,
    pci_frame_in,
    pci_stop_in,

    init_complete_in
);

input reset_in, clk_in ;

input           frame_in ;
input           frame_en_in ;
input           frame_load_in ;
input           irdy_in ;
input           irdy_en_in ;
input           devsel_in ;
input           devsel_en_in ;
input           trdy_in ;
input           trdy_en_in ;
input           stop_in ;
input           stop_en_in ;
input           master_load_in ;
input           target_load_in ;

input [3:0]     cbe_in ;
input           cbe_en_in ;
input [31:0]    mas_ad_in ;
input [31:0]    tar_ad_in ;

input           mas_ad_en_in ;
input           tar_ad_en_in ;
input           tar_ad_en_reg_in ;

input par_in ;
input par_en_in ;
input perr_in ;
input perr_en_in ;
input serr_in ;
input serr_en_in ;

output          frame_en_out ;
output          irdy_en_out ;
output          devsel_en_out ;
output          trdy_en_out ;
output          stop_en_out ;
output [31:0]   ad_en_out ;
output [3:0]    cbe_en_out ;

output          frame_out ;
output          irdy_out ;
output          devsel_out ;
output          trdy_out ;
output          stop_out ;
output [3:0]    cbe_out ;
output [31:0]   ad_out ;
output          ad_load_out ;
output          ad_en_unregistered_out ;

output          par_out ;
output          par_en_out ;
output          perr_out ;
output          perr_en_out ;
output          serr_out ;
output          serr_en_out ;

input           req_in ;

output          req_out ;
output          req_en_out ;

input           pci_trdy_in,
                pci_irdy_in,
                pci_frame_in,
                pci_stop_in ;

input           master_load_on_transfer_in ;
input           target_load_on_transfer_in ;

input           init_complete_in    ;

wire   [31:0]   temp_ad = tar_ad_en_reg_in ? tar_ad_in : mas_ad_in ;

wire ad_en_ctrl_low ;

wire ad_en_ctrl_mlow ;

wire ad_en_ctrl_mhigh ;

wire ad_en_ctrl_high ;

wire ad_enable_internal = mas_ad_en_in || tar_ad_en_in ;

pci_io_mux_ad_en_crit ad_en_low_gen
(
    .ad_en_in       (ad_enable_internal),
    .pci_frame_in   (pci_frame_in),
    .pci_trdy_in    (pci_trdy_in),
    .pci_stop_in    (pci_stop_in),
    .ad_en_out      (ad_en_ctrl_low)
);

pci_io_mux_ad_en_crit ad_en_mlow_gen
(
    .ad_en_in       (ad_enable_internal),
    .pci_frame_in   (pci_frame_in),
    .pci_trdy_in    (pci_trdy_in),
    .pci_stop_in    (pci_stop_in),
    .ad_en_out      (ad_en_ctrl_mlow)
);

pci_io_mux_ad_en_crit ad_en_mhigh_gen
(
    .ad_en_in       (ad_enable_internal),
    .pci_frame_in   (pci_frame_in),
    .pci_trdy_in    (pci_trdy_in),
    .pci_stop_in    (pci_stop_in),
    .ad_en_out      (ad_en_ctrl_mhigh)
);

pci_io_mux_ad_en_crit ad_en_high_gen
(
    .ad_en_in       (ad_enable_internal),
    .pci_frame_in   (pci_frame_in),
    .pci_trdy_in    (pci_trdy_in),
    .pci_stop_in    (pci_stop_in),
    .ad_en_out      (ad_en_ctrl_high)
);

assign ad_en_unregistered_out = ad_en_ctrl_high ;

wire load = master_load_in || target_load_in ;
wire load_on_transfer = master_load_on_transfer_in || target_load_on_transfer_in ;

wire   ad_load_ctrl_low ;
wire   ad_load_ctrl_mlow ;
wire   ad_load_ctrl_mhigh ;
wire   ad_load_ctrl_high ;

assign ad_load_out = ad_load_ctrl_high ;

pci_io_mux_ad_load_crit ad_load_low_gen
(
    .load_in(load),
    .load_on_transfer_in(load_on_transfer),
    .pci_irdy_in(pci_irdy_in),
    .pci_trdy_in(pci_trdy_in),
    .load_out(ad_load_ctrl_low)
);

pci_io_mux_ad_load_crit ad_load_mlow_gen
(
    .load_in(load),
    .load_on_transfer_in(load_on_transfer),
    .pci_irdy_in(pci_irdy_in),
    .pci_trdy_in(pci_trdy_in),
    .load_out(ad_load_ctrl_mlow)
);

pci_io_mux_ad_load_crit ad_load_mhigh_gen
(
    .load_in(load),
    .load_on_transfer_in(load_on_transfer),
    .pci_irdy_in(pci_irdy_in),
    .pci_trdy_in(pci_trdy_in),
    .load_out(ad_load_ctrl_mhigh)
);

pci_io_mux_ad_load_crit ad_load_high_gen
(
    .load_in(load),
    .load_on_transfer_in(load_on_transfer),
    .pci_irdy_in(pci_irdy_in),
    .pci_trdy_in(pci_trdy_in),
    .load_out(ad_load_ctrl_high)
);

pci_out_reg ad_iob0
(
    .reset_in     ( reset_in ),
    .clk_in       ( clk_in) ,
    .dat_en_in    ( ad_load_ctrl_low ),
    .en_en_in     ( 1'b1 ),
    .dat_in       ( temp_ad[0] ) ,
    .en_in        ( ad_en_ctrl_low ) ,
    .en_out       ( ad_en_out[0] ),
    .dat_out      ( ad_out[0] )
);

pci_out_reg ad_iob1
(
    .reset_in     ( reset_in ),
    .clk_in       ( clk_in) ,
    .dat_en_in    ( ad_load_ctrl_low ),
    .en_en_in     ( 1'b1 ),
    .dat_in       ( temp_ad[1] ) ,
    .en_in        ( ad_en_ctrl_low ) ,
    .en_out       ( ad_en_out[1] ),
    .dat_out      ( ad_out[1] )
);

pci_out_reg ad_iob2
(
    .reset_in     ( reset_in ),
    .clk_in       ( clk_in) ,
    .dat_en_in    ( ad_load_ctrl_low ),
    .en_en_in     ( 1'b1 ),
    .dat_in       ( temp_ad[2] ) ,
    .en_in        ( ad_en_ctrl_low ) ,
    .en_out       ( ad_en_out[2] ),
    .dat_out      ( ad_out[2] )
);

pci_out_reg ad_iob3
(
    .reset_in     ( reset_in ),
    .clk_in       ( clk_in) ,
    .dat_en_in    ( ad_load_ctrl_low ),
    .en_en_in     ( 1'b1 ),
    .dat_in       ( temp_ad[3] ) ,
    .en_in        ( ad_en_ctrl_low ) ,
    .en_out       ( ad_en_out[3] ),
    .dat_out      ( ad_out[3] )
);

pci_out_reg ad_iob4
(
    .reset_in     ( reset_in ),
    .clk_in       ( clk_in) ,
    .dat_en_in    ( ad_load_ctrl_low ),
    .en_en_in     ( 1'b1 ),
    .dat_in       ( temp_ad[4] ) ,
    .en_in        ( ad_en_ctrl_low ) ,
    .en_out       ( ad_en_out[4] ),
    .dat_out      ( ad_out[4] )
);

pci_out_reg ad_iob5
(
    .reset_in     ( reset_in ),
    .clk_in       ( clk_in) ,
    .dat_en_in    ( ad_load_ctrl_low ),
    .en_en_in     ( 1'b1 ),
    .dat_in       ( temp_ad[5] ) ,
    .en_in        ( ad_en_ctrl_low ) ,
    .en_out       ( ad_en_out[5] ),
    .dat_out      ( ad_out[5] )
);

pci_out_reg ad_iob6
(
    .reset_in     ( reset_in ),
    .clk_in       ( clk_in) ,
    .dat_en_in    ( ad_load_ctrl_low ),
    .en_en_in     ( 1'b1 ),
    .dat_in       ( temp_ad[6] ) ,
    .en_in        ( ad_en_ctrl_low ) ,
    .en_out       ( ad_en_out[6] ),
    .dat_out      ( ad_out[6] )
);

pci_out_reg ad_iob7
(
    .reset_in     ( reset_in ),
    .clk_in       ( clk_in) ,
    .dat_en_in    ( ad_load_ctrl_low ),
    .en_en_in     ( 1'b1 ),
    .dat_in       ( temp_ad[7] ) ,
    .en_in        ( ad_en_ctrl_low ) ,
    .en_out       ( ad_en_out[7] ),
    .dat_out      ( ad_out[7] )
);

pci_out_reg ad_iob8
(
    .reset_in     ( reset_in ),
    .clk_in       ( clk_in) ,
    .dat_en_in    ( ad_load_ctrl_mlow ),
    .en_en_in     ( 1'b1 ),
    .dat_in       ( temp_ad[8] ) ,
    .en_in        ( ad_en_ctrl_mlow ) ,
    .en_out       ( ad_en_out[8] ),
    .dat_out      ( ad_out[8] )
);

pci_out_reg ad_iob9
(
    .reset_in     ( reset_in ),
    .clk_in       ( clk_in) ,
    .dat_en_in    ( ad_load_ctrl_mlow ),
    .en_en_in     ( 1'b1 ),
    .dat_in       ( temp_ad[9] ) ,
    .en_in        ( ad_en_ctrl_mlow ) ,
    .en_out       ( ad_en_out[9] ),