////////////////////////////////////////////////////////////////////// //// //// //// uart_wb.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 //// //// - Igor Mohor (igorm@opencores.org) //// //// //// //// Created: 2001/05/12 //// //// Last Updated: 2001/05/17 //// //// (See log for the revision history) //// //// //// //// //// ////////////////////////////////////////////////////////////////////// //// //// //// Copyright (C) 2000, 2001 Authors //// //// //// //// 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: not supported by cvs2svn $ // Revision 1.8 2001/08/24 21:01:12 mohor // Things connected to parity changed. // Clock devider changed. // // Revision 1.7 2001/08/23 16:05:05 mohor // Stop bit bug fixed. // Parity bug fixed. // WISHBONE read cycle bug fixed, // OE indicator (Overrun Error) bug fixed. // PE indicator (Parity Error) bug fixed. // Register read bug fixed. // // 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 // // synopsys translate_off `include "timescale.v" // synopsys translate_on 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