Subversion Repositories usb2uart

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

////                                                             ////

////  USB 1.1 PHY                                                ////

////                                                             ////

////                                                             ////

////  Author: Rudolf Usselmann                                   ////

////          rudi@asics.ws                                      ////

////                                                             ////

////                                                             ////

////  Downloaded from: http://www.opencores.org/cores/usb_phy/   ////

////                                                             ////

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

////                                                             ////

//// Copyright (C) 2000-2002 Rudolf Usselmann                    ////

////                         www.asics.ws                        ////

////                         rudi@asics.ws                       ////

////                                                             ////

//// 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 SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY     ////

//// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED   ////

//// TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS   ////

//// FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL THE AUTHOR      ////

//// OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,         ////

//// INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES    ////

//// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE   ////

//// GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR        ////

//// BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF  ////

//// LIABILITY, WHETHER IN  CONTRACT, STRICT LIABILITY, OR TORT  ////

//// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT  ////

//// OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE         ////

//// POSSIBILITY OF SUCH DAMAGE.                                 ////

////                                                             ////

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

//  CVS Log

//

//  $Id: usb_phy.v,v 1.4 2003-10-21 05:58:40 rudi Exp $

//

//  $Date: 2003-10-21 05:58:40 $

//  $Revision: 1.4 $

//  $Author: rudi $

//  $Locker:  $

//  $State: Exp $

//

// Change History:

//               $Log: not supported by cvs2svn $

//               Revision 1.3  2003/10/19 17:40:13  rudi

//               - Made core more robust against line noise

//               - Added Error Checking and Reporting

//               (See README.txt for more info)

//

//               Revision 1.2  2002/09/16 16:06:37  rudi

//               Changed top level name to be consistent ...

//

//               Revision 1.1.1.1  2002/09/16 14:26:59  rudi

//               Created Directory Structure

//

//

//

//

//

//

//

//

`include "timescale.v"

module usb_phy(clk, rst, phy_tx_mode, usb_rst,

                // Transciever Interface

                txdp, txdn, txoe,

                rxd, rxdp, rxdn,

                // UTMI Interface

                DataOut_i, TxValid_i, TxReady_o, RxValid_o,

                RxActive_o, RxError_o, DataIn_o, LineState_o

                );

/***************************************

*  Comman Signal

*  *************************************/

input           clk              ; // 48Mhz clock

input           rst              ; // Active low async reset

input           phy_tx_mode      ; // Used in Tx Path,

                                   // The PHY supports single ended and differential output to the

                                   // transceiver Depending on which device you are using, you have

                                   // to tie the phy_tx_mode high or low. 

output          usb_rst          ; // usb_rst is asserted whenever the host signals reset on the USB bus.

                                   // The USB core will internally reset itself automatically.

                                   // This output is provided for external logic that needs to be

                                   // reset when the USB bus is reset.

output          txdp, txdn, txoe;

input           rxd, rxdp, rxdn;

input   [7:0]    DataOut_i;

input           TxValid_i;

output          TxReady_o;

output  [7:0]    DataIn_o;

output          RxValid_o;

output          RxActive_o;

output          RxError_o;

output  [1:0]    LineState_o;

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

//

// Local Wires and Registers

//

reg     [4:0]    rst_cnt;

reg             usb_rst;

wire            fs_ce;

wire            rst;

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

//

// Misc Logic

//

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

//

// TX Phy

//

usb_tx_phy i_tx_phy(

        .clk(           clk             ),

        .rst(           rst             ),

        .fs_ce(         fs_ce           ),

        .phy_mode(      phy_tx_mode     ),

        // Transciever Interface

        .txdp(          txdp            ),

        .txdn(          txdn            ),

        .txoe(          txoe            ),

        // UTMI Interface

        .DataOut_i(     DataOut_i       ),

        .TxValid_i(     TxValid_i       ),

        .TxReady_o(     TxReady_o       )

        );

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

//

// RX Phy and DPLL

//

usb_rx_phy i_rx_phy(

        .clk(           clk             ),

        .rst(           rst             ),

        .fs_ce(         fs_ce           ),

        // Transciever Interface

        .rxd(           rxd             ),

        .rxdp(          rxdp            ),

        .rxdn(          rxdn            ),

        // UTMI Interface

        .DataIn_o(      DataIn_o        ),

        .RxValid_o(     RxValid_o       ),

        .RxActive_o(    RxActive_o      ),

        .RxError_o(     RxError_o       ),

        .RxEn_i(        txoe            ),

        .LineState(     LineState_o     )

        );

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

//

// Generate an USB Reset is we see SE0 for at least 2.5uS

//

`ifdef USB_ASYNC_REST

always @(posedge clk or negedge rst)

`else

always @(posedge clk)

`endif

        if(!rst)                        rst_cnt <= 5'h0;

        else

        if(LineState_o != 2'h0)         rst_cnt <= 5'h0;

        else

        if(!usb_rst && fs_ce)           rst_cnt <= rst_cnt + 5'h1;

always @(posedge clk)

        usb_rst <= (rst_cnt == 5'h1f);

endmodule