Subversion Repositories or1k_soc_on_altera_embedded_dev_kit

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

////                                                              ////

////  uart_TX_FIFO.v                                              ////

////                                                              ////

////                                                              ////

////  This file is part of the "UART 16550 compatible" project    ////

////  http://www.opencores.org/cores/uart16550/                   ////

////                                                              ////

////  Documentation related to this project:                      ////

////  - http://www.opencores.org/cores/uart16550/                 ////

////                                                              ////

////  Projects compatibility:                                     ////

////  - WISHBONE                                                  ////

////  RS232 Protocol                                              ////

////  16550D uart (mostly supported)                              ////

////                                                              ////

////  Overview (main Features):                                   ////

////  UART core WISHBONE interface.                               ////

////                                                              ////

////  Known problems (limits):                                    ////

////  Inserts one wait state on all transfers.                    ////

////  Note affected signals and the way they are affected.        ////

////                                                              ////

////  To Do:                                                      ////

////  Nothing.                                                    ////

////                                                              ////

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

////      - gorban@opencores.org                                  ////

////      - Jacob Gorban                                          ////

////                                                              ////

////  Created:        2001/05/12                                  ////

////  Last Updated:   2001/05/17                                  ////

////                  (See log for the revision history)          ////

////                                                              ////

////                                                              ////

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

////                                                              ////

//// Copyright (C) 2000 Jacob Gorban, gorban@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: uart_wb.v,v $

// Revision 1.4  2001/05/31 20:08:01  gorban

// FIFO changes and other corrections.

//

// Revision 1.3  2001/05/21 19:12:01  gorban

// Corrected some Linter messages.

//

// Revision 1.2  2001/05/17 18:34:18  gorban

// First 'stable' release. Should be sythesizable now. Also added new header.

//

// Revision 1.0  2001-05-17 21:27:13+02  jacob

// Initial revision

//

//

// UART core WISHBONE interface 

//

// Author: Jacob Gorban   (jacob.gorban@flextronicssemi.com)

// Company: Flextronics Semiconductor

//

`include "timescale.v"

module uart_wb (clk,

        wb_rst_i,

        wb_we_i, wb_stb_i, wb_cyc_i, wb_ack_o,

        we_o, re_o // Write and read enable output for the core

        );

input                           clk;

// WISHBONE interface   

input                           wb_rst_i;

input                           wb_we_i;

input                           wb_stb_i;

input                           wb_cyc_i;

output                          wb_ack_o;

output                          we_o;

output                          re_o;

wire                            we_o;

reg                             wb_ack_o;

always @(posedge clk or posedge wb_rst_i)

begin

        if (wb_rst_i)

        begin

                wb_ack_o <= #1 1'b0;

        end

        else

        begin

//              wb_ack_o <= #1 wb_stb_i & wb_cyc_i; // 1 clock wait state on all transfers

                wb_ack_o <= #1 wb_stb_i & wb_cyc_i & ~wb_ack_o; // 1 clock wait state on all transfers

        end

end

assign we_o =  wb_we_i & wb_cyc_i & wb_stb_i; //WE for registers        

assign re_o = ~wb_we_i & wb_cyc_i & wb_stb_i; //RE for registers        

endmodule