//////////////////////////////////////////////////////////////////////
//// ////
//// uart_top.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 top level. ////
//// ////
//// Known problems (limits): ////
//// Note that transmitter and receiver instances are inside ////
//// the uart_regs.v file. ////
//// ////
//// To Do: ////
//// Nothing so far. ////
//// ////
//// 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 1.18 2002/07/22 23:02:23 gorban
// Bug Fixes:
// * Possible loss of sync and bad reception of stop bit on slow baud rates fixed.
// Problem reported by Kenny.Tung.
// * Bad (or lack of ) loopback handling fixed. Reported by Cherry Withers.
//
// Improvements:
// * Made FIFO's as general inferrable memory where possible.
// So on FPGA they should be inferred as RAM (Distributed RAM on Xilinx).
// This saves about 1/3 of the Slice count and reduces P&R and synthesis times.
//
// * Added optional baudrate output (baud_o).
// This is identical to BAUDOUT* signal on 16550 chip.
// It outputs 16xbit_clock_rate - the divided clock.
// It's disabled by default. Define UART_HAS_BAUDRATE_OUTPUT to use.
//
// Revision 1.17 2001/12/19 08:40:03 mohor
// Warnings fixed (unused signals removed).
//
// Revision 1.16 2001/12/06 14:51:04 gorban
// Bug in LSR[0] is fixed.
// All WISHBONE signals are now sampled, so another wait-state is introduced on all transfers.
//
// Revision 1.15 2001/12/03 21:44:29 gorban
// Updated specification documentation.
// Added full 32-bit data bus interface, now as default.
// Address is 5-bit wide in 32-bit data bus mode.
// Added wb_sel_i input to the core. It's used in the 32-bit mode.
// Added debug interface with two 32-bit read-only registers in 32-bit mode.
// Bits 5 and 6 of LSR are now only cleared on TX FIFO write.
// My small test bench is modified to work with 32-bit mode.
//
// Revision 1.14 2001/11/07 17:51:52 gorban
// Heavily rewritten interrupt and LSR subsystems.
// Many bugs hopefully squashed.
//
// Revision 1.13 2001/10/20 09:58:40 gorban
// Small synopsis fixes
//
// Revision 1.12 2001/08/25 15:46:19 gorban
// Modified port names again
//
// Revision 1.11 2001/08/24 21:01:12 mohor
// Things connected to parity changed.
// Clock devider changed.
//
// Revision 1.10 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 19:12:02 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 21:27:12+02 jacob
// Initial revision
//
//
`include "uart_defines.v"
module uart_top (
wb_clk_i,
// Wishbone signals
wb_rst_i, wb_adr_i, wb_dat_i, wb_dat_o, wb_we_i, wb_stb_i, wb_cyc_i, wb_ack_o, wb_sel_i,
int_o, // interrupt request
// UART signals
// serial input/output
stx_pad_o, srx_pad_i,
// modem signals
rts_pad_o, cts_pad_i, dtr_pad_o, dsr_pad_i, ri_pad_i, dcd_pad_i
`ifdef UART_HAS_BAUDRATE_OUTPUT
, baud_o
`endif
);
parameter SIM = 0;
parameter debug = 0;
input wb_clk_i;
// WISHBONE interface
input wb_rst_i;
input [2:0] wb_adr_i;
input [7:0] wb_dat_i;
output [7:0] wb_dat_o;
input wb_we_i;
input wb_stb_i;
input wb_cyc_i;
input [3:0] wb_sel_i;
output wb_ack_o;
output int_o;
// UART signals
input srx_pad_i;
output stx_pad_o;
output rts_pad_o;
input cts_pad_i;
output dtr_pad_o;
input dsr_pad_i;
input ri_pad_i;
input dcd_pad_i;
// optional baudrate output
`ifdef UART_HAS_BAUDRATE_OUTPUT
output baud_o;
`endif
wire stx_pad_o;
wire rts_pad_o;
wire dtr_pad_o;
wire [2:0] wb_adr_i;
wire [7:0] wb_dat_i;
wire [7:0] wb_dat_o;
wire [7:0] wb_dat8_i; // 8-bit internal data input
wire [7:0] wb_dat8_o; // 8-bit internal data output
wire [31:0] wb_dat32_o; // debug interface 32-bit output
wire [3:0] wb_sel_i; // WISHBONE select signal
wire [2:0] wb_adr_int;
wire we_o; // Write enable for registers
wire re_o; // Read enable for registers
//
// MODULE INSTANCES
//
//// WISHBONE interface module
uart_wb wb_interface(
.clk( wb_clk_i ),
.wb_rst_i( wb_rst_i ),
.wb_dat_i(wb_dat_i),
.wb_dat_o(wb_dat_o),
.wb_dat8_i(wb_dat8_i),
.wb_dat8_o(wb_dat8_o),
.wb_dat32_o(32'b0),
.wb_sel_i(4'b0),
.wb_we_i( wb_we_i ),
.wb_stb_i( wb_stb_i ),
.wb_cyc_i( wb_cyc_i ),
.wb_ack_o( wb_ack_o ),
.wb_adr_i(wb_adr_i),
.wb_adr_int(wb_adr_int),
.we_o( we_o ),
.re_o(re_o)
);
// Registers
uart_regs #(.SIM (SIM)) regs(
.clk( wb_clk_i ),
.wb_rst_i( wb_rst_i ),
.wb_addr_i( wb_adr_int ),
.wb_dat_i( wb_dat8_i ),
.wb_dat_o( wb_dat8_o ),
.wb_we_i( we_o ),
.wb_re_i(re_o),
.modem_inputs( {cts_pad_i, dsr_pad_i,
ri_pad_i, dcd_pad_i} ),
.stx_pad_o( stx_pad_o ),
.srx_pad_i( srx_pad_i ),
.rts_pad_o( rts_pad_o ),
.dtr_pad_o( dtr_pad_o ),
.int_o( int_o )
`ifdef UART_HAS_BAUDRATE_OUTPUT
, .baud_o(baud_o)
`endif
);
initial
begin
if(debug) begin
`ifdef UART_HAS_BAUDRATE_OUTPUT
$display("(%m) UART INFO: Has baudrate output\n");
`else
$display("(%m) UART INFO: Doesn't have baudrate output\n");
`endif
end
end
endmodule