[6] | 1 | ////////////////////////////////////////////////////////////////////// |
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| 2 | //// //// |
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| 3 | //// uart_top.v //// |
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| 4 | //// //// |
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| 5 | //// //// |
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| 6 | //// This file is part of the "UART 16550 compatible" project //// |
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| 7 | //// http://www.opencores.org/cores/uart16550/ //// |
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| 8 | //// //// |
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| 9 | //// Documentation related to this project: //// |
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| 10 | //// - http://www.opencores.org/cores/uart16550/ //// |
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| 11 | //// //// |
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| 12 | //// Projects compatibility: //// |
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| 13 | //// - WISHBONE //// |
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| 14 | //// RS232 Protocol //// |
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| 15 | //// 16550D uart (mostly supported) //// |
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| 16 | //// //// |
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| 17 | //// Overview (main Features): //// |
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| 18 | //// UART core top level. //// |
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| 19 | //// //// |
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| 20 | //// Known problems (limits): //// |
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| 21 | //// Note that transmitter and receiver instances are inside //// |
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| 22 | //// the uart_regs.v file. //// |
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| 23 | //// //// |
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| 24 | //// To Do: //// |
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| 25 | //// Nothing so far. //// |
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| 26 | //// //// |
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| 27 | //// Author(s): //// |
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| 28 | //// - gorban@opencores.org //// |
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| 29 | //// - Jacob Gorban //// |
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| 30 | //// - Igor Mohor (igorm@opencores.org) //// |
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| 31 | //// //// |
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| 32 | //// Created: 2001/05/12 //// |
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| 33 | //// Last Updated: 2001/05/17 //// |
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| 34 | //// (See log for the revision history) //// |
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| 35 | //// //// |
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| 36 | //// //// |
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| 37 | ////////////////////////////////////////////////////////////////////// |
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| 38 | //// //// |
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| 39 | //// Copyright (C) 2000, 2001 Authors //// |
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| 40 | //// //// |
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| 41 | //// This source file may be used and distributed without //// |
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| 42 | //// restriction provided that this copyright statement is not //// |
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| 43 | //// removed from the file and that any derivative work contains //// |
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| 44 | //// the original copyright notice and the associated disclaimer. //// |
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| 45 | //// //// |
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| 46 | //// This source file is free software; you can redistribute it //// |
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| 47 | //// and/or modify it under the terms of the GNU Lesser General //// |
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| 48 | //// Public License as published by the Free Software Foundation; //// |
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| 49 | //// either version 2.1 of the License, or (at your option) any //// |
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| 50 | //// later version. //// |
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| 51 | //// //// |
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| 52 | //// This source is distributed in the hope that it will be //// |
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| 53 | //// useful, but WITHOUT ANY WARRANTY; without even the implied //// |
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| 54 | //// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR //// |
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| 55 | //// PURPOSE. See the GNU Lesser General Public License for more //// |
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| 56 | //// details. //// |
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| 57 | //// //// |
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| 58 | //// You should have received a copy of the GNU Lesser General //// |
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| 59 | //// Public License along with this source; if not, download it //// |
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| 60 | //// from http://www.opencores.org/lgpl.shtml //// |
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| 61 | //// //// |
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| 62 | ////////////////////////////////////////////////////////////////////// |
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| 63 | // |
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| 64 | // CVS Revision History |
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| 65 | // |
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| 66 | // $Log: not supported by cvs2svn $ |
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| 67 | // Revision 1.18 2002/07/22 23:02:23 gorban |
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| 68 | // Bug Fixes: |
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| 69 | // * Possible loss of sync and bad reception of stop bit on slow baud rates fixed. |
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| 70 | // Problem reported by Kenny.Tung. |
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| 71 | // * Bad (or lack of ) loopback handling fixed. Reported by Cherry Withers. |
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| 72 | // |
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| 73 | // Improvements: |
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| 74 | // * Made FIFO's as general inferrable memory where possible. |
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| 75 | // So on FPGA they should be inferred as RAM (Distributed RAM on Xilinx). |
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| 76 | // This saves about 1/3 of the Slice count and reduces P&R and synthesis times. |
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| 77 | // |
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| 78 | // * Added optional baudrate output (baud_o). |
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| 79 | // This is identical to BAUDOUT* signal on 16550 chip. |
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| 80 | // It outputs 16xbit_clock_rate - the divided clock. |
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| 81 | // It's disabled by default. Define UART_HAS_BAUDRATE_OUTPUT to use. |
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| 82 | // |
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| 83 | // Revision 1.17 2001/12/19 08:40:03 mohor |
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| 84 | // Warnings fixed (unused signals removed). |
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| 85 | // |
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| 86 | // Revision 1.16 2001/12/06 14:51:04 gorban |
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| 87 | // Bug in LSR[0] is fixed. |
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| 88 | // All WISHBONE signals are now sampled, so another wait-state is introduced on all transfers. |
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| 89 | // |
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| 90 | // Revision 1.15 2001/12/03 21:44:29 gorban |
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| 91 | // Updated specification documentation. |
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| 92 | // Added full 32-bit data bus interface, now as default. |
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| 93 | // Address is 5-bit wide in 32-bit data bus mode. |
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| 94 | // Added wb_sel_i input to the core. It's used in the 32-bit mode. |
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| 95 | // Added debug interface with two 32-bit read-only registers in 32-bit mode. |
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| 96 | // Bits 5 and 6 of LSR are now only cleared on TX FIFO write. |
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| 97 | // My small test bench is modified to work with 32-bit mode. |
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| 98 | // |
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| 99 | // Revision 1.14 2001/11/07 17:51:52 gorban |
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| 100 | // Heavily rewritten interrupt and LSR subsystems. |
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| 101 | // Many bugs hopefully squashed. |
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| 102 | // |
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| 103 | // Revision 1.13 2001/10/20 09:58:40 gorban |
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| 104 | // Small synopsis fixes |
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| 105 | // |
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| 106 | // Revision 1.12 2001/08/25 15:46:19 gorban |
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| 107 | // Modified port names again |
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| 108 | // |
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| 109 | // Revision 1.11 2001/08/24 21:01:12 mohor |
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| 110 | // Things connected to parity changed. |
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| 111 | // Clock devider changed. |
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| 112 | // |
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| 113 | // Revision 1.10 2001/08/23 16:05:05 mohor |
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| 114 | // Stop bit bug fixed. |
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| 115 | // Parity bug fixed. |
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| 116 | // WISHBONE read cycle bug fixed, |
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| 117 | // OE indicator (Overrun Error) bug fixed. |
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| 118 | // PE indicator (Parity Error) bug fixed. |
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| 119 | // Register read bug fixed. |
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| 120 | // |
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| 121 | // Revision 1.4 2001/05/31 20:08:01 gorban |
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| 122 | // FIFO changes and other corrections. |
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| 123 | // |
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| 124 | // Revision 1.3 2001/05/21 19:12:02 gorban |
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| 125 | // Corrected some Linter messages. |
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| 126 | // |
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| 127 | // Revision 1.2 2001/05/17 18:34:18 gorban |
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| 128 | // First 'stable' release. Should be sythesizable now. Also added new header. |
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| 129 | // |
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| 130 | // Revision 1.0 2001-05-17 21:27:12+02 jacob |
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| 131 | // Initial revision |
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| 132 | // |
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| 133 | // |
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| 134 | // synopsys translate_off |
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| 135 | `include "timescale.v" |
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| 136 | // synopsys translate_on |
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| 137 | |
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| 138 | `include "uart_defines.v" |
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| 139 | |
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| 140 | module uart_top ( |
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| 141 | wb_clk_i, |
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| 142 | |
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| 143 | // Wishbone signals |
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| 144 | 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, |
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| 145 | int_o, // interrupt request |
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| 146 | |
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| 147 | // UART signals |
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| 148 | // serial input/output |
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| 149 | stx_pad_o, srx_pad_i, |
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| 150 | |
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| 151 | // modem signals |
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| 152 | rts_pad_o, cts_pad_i, dtr_pad_o, dsr_pad_i, ri_pad_i, dcd_pad_i |
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| 153 | `ifdef UART_HAS_BAUDRATE_OUTPUT |
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| 154 | , baud_o |
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| 155 | `endif |
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| 156 | ); |
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| 157 | |
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| 158 | parameter uart_data_width = `UART_DATA_WIDTH; |
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| 159 | parameter uart_addr_width = `UART_ADDR_WIDTH; |
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| 160 | |
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| 161 | input wb_clk_i; |
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| 162 | |
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| 163 | // WISHBONE interface |
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| 164 | input wb_rst_i; |
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| 165 | input [uart_addr_width-1:0] wb_adr_i; |
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| 166 | input [uart_data_width-1:0] wb_dat_i; |
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| 167 | output [uart_data_width-1:0] wb_dat_o; |
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| 168 | input wb_we_i; |
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| 169 | input wb_stb_i; |
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| 170 | input wb_cyc_i; |
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| 171 | input [3:0] wb_sel_i; |
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| 172 | output wb_ack_o; |
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| 173 | output int_o; |
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| 174 | |
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| 175 | // UART signals |
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| 176 | input srx_pad_i; |
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| 177 | output stx_pad_o; |
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| 178 | output rts_pad_o; |
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| 179 | input cts_pad_i; |
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| 180 | output dtr_pad_o; |
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| 181 | input dsr_pad_i; |
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| 182 | input ri_pad_i; |
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| 183 | input dcd_pad_i; |
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| 184 | |
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| 185 | // optional baudrate output |
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| 186 | `ifdef UART_HAS_BAUDRATE_OUTPUT |
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| 187 | output baud_o; |
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| 188 | `endif |
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| 189 | |
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| 190 | |
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| 191 | wire stx_pad_o; |
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| 192 | wire rts_pad_o; |
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| 193 | wire dtr_pad_o; |
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| 194 | |
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| 195 | wire [uart_addr_width-1:0] wb_adr_i; |
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| 196 | wire [uart_data_width-1:0] wb_dat_i; |
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| 197 | wire [uart_data_width-1:0] wb_dat_o; |
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| 198 | |
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| 199 | wire [7:0] wb_dat8_i; // 8-bit internal data input |
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| 200 | wire [7:0] wb_dat8_o; // 8-bit internal data output |
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| 201 | wire [31:0] wb_dat32_o; // debug interface 32-bit output |
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| 202 | wire [3:0] wb_sel_i; // WISHBONE select signal |
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| 203 | wire [uart_addr_width-1:0] wb_adr_int; |
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| 204 | wire we_o; // Write enable for registers |
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| 205 | wire re_o; // Read enable for registers |
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| 206 | // |
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| 207 | // MODULE INSTANCES |
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| 208 | // |
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| 209 | |
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| 210 | `ifdef DATA_BUS_WIDTH_8 |
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| 211 | `else |
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| 212 | // debug interface wires |
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| 213 | wire [3:0] ier; |
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| 214 | wire [3:0] iir; |
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| 215 | wire [1:0] fcr; |
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| 216 | wire [4:0] mcr; |
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| 217 | wire [7:0] lcr; |
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| 218 | wire [7:0] msr; |
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| 219 | wire [7:0] lsr; |
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| 220 | wire [`UART_FIFO_COUNTER_W-1:0] rf_count; |
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| 221 | wire [`UART_FIFO_COUNTER_W-1:0] tf_count; |
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| 222 | wire [2:0] tstate; |
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| 223 | wire [3:0] rstate; |
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| 224 | `endif |
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| 225 | |
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| 226 | `ifdef DATA_BUS_WIDTH_8 |
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| 227 | //// WISHBONE interface module |
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| 228 | uart_wb wb_interface( |
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| 229 | .clk( wb_clk_i ), |
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| 230 | .wb_rst_i( wb_rst_i ), |
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| 231 | .wb_dat_i(wb_dat_i), |
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| 232 | .wb_dat_o(wb_dat_o), |
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| 233 | .wb_dat8_i(wb_dat8_i), |
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| 234 | .wb_dat8_o(wb_dat8_o), |
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| 235 | .wb_dat32_o(32'b0), |
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| 236 | .wb_sel_i(4'b0), |
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| 237 | .wb_we_i( wb_we_i ), |
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| 238 | .wb_stb_i( wb_stb_i ), |
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| 239 | .wb_cyc_i( wb_cyc_i ), |
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| 240 | .wb_ack_o( wb_ack_o ), |
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| 241 | .wb_adr_i(wb_adr_i), |
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| 242 | .wb_adr_int(wb_adr_int), |
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| 243 | .we_o( we_o ), |
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| 244 | .re_o(re_o) |
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| 245 | ); |
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| 246 | `else |
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| 247 | uart_wb wb_interface( |
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| 248 | .clk( wb_clk_i ), |
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| 249 | .wb_rst_i( wb_rst_i ), |
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| 250 | .wb_dat_i(wb_dat_i), |
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| 251 | .wb_dat_o(wb_dat_o), |
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| 252 | .wb_dat8_i(wb_dat8_i), |
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| 253 | .wb_dat8_o(wb_dat8_o), |
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| 254 | .wb_sel_i(wb_sel_i), |
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| 255 | .wb_dat32_o(wb_dat32_o), |
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| 256 | .wb_we_i( wb_we_i ), |
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| 257 | .wb_stb_i( wb_stb_i ), |
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| 258 | .wb_cyc_i( wb_cyc_i ), |
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| 259 | .wb_ack_o( wb_ack_o ), |
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| 260 | .wb_adr_i(wb_adr_i), |
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| 261 | .wb_adr_int(wb_adr_int), |
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| 262 | .we_o( we_o ), |
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| 263 | .re_o(re_o) |
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| 264 | ); |
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| 265 | `endif |
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| 266 | |
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| 267 | // Registers |
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| 268 | uart_regs regs( |
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| 269 | .clk( wb_clk_i ), |
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| 270 | .wb_rst_i( wb_rst_i ), |
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| 271 | .wb_addr_i( wb_adr_int ), |
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| 272 | .wb_dat_i( wb_dat8_i ), |
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| 273 | .wb_dat_o( wb_dat8_o ), |
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| 274 | .wb_we_i( we_o ), |
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| 275 | .wb_re_i(re_o), |
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| 276 | .modem_inputs( {cts_pad_i, dsr_pad_i, |
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| 277 | ri_pad_i, dcd_pad_i} ), |
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| 278 | .stx_pad_o( stx_pad_o ), |
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| 279 | .srx_pad_i( srx_pad_i ), |
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| 280 | `ifdef DATA_BUS_WIDTH_8 |
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| 281 | `else |
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| 282 | // debug interface signals enabled |
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| 283 | .ier(ier), |
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| 284 | .iir(iir), |
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| 285 | .fcr(fcr), |
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| 286 | .mcr(mcr), |
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| 287 | .lcr(lcr), |
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| 288 | .msr(msr), |
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| 289 | .lsr(lsr), |
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| 290 | .rf_count(rf_count), |
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| 291 | .tf_count(tf_count), |
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| 292 | .tstate(tstate), |
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| 293 | .rstate(rstate), |
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| 294 | `endif |
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| 295 | .rts_pad_o( rts_pad_o ), |
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| 296 | .dtr_pad_o( dtr_pad_o ), |
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| 297 | .int_o( int_o ) |
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| 298 | `ifdef UART_HAS_BAUDRATE_OUTPUT |
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| 299 | , .baud_o(baud_o) |
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| 300 | `endif |
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| 301 | |
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| 302 | ); |
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| 303 | |
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| 304 | `ifdef DATA_BUS_WIDTH_8 |
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| 305 | `else |
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| 306 | uart_debug_if dbg(/*AUTOINST*/ |
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| 307 | // Outputs |
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| 308 | .wb_dat32_o (wb_dat32_o[31:0]), |
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| 309 | // Inputs |
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| 310 | .wb_adr_i (wb_adr_int[`UART_ADDR_WIDTH-1:0]), |
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| 311 | .ier (ier[3:0]), |
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| 312 | .iir (iir[3:0]), |
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| 313 | .fcr (fcr[1:0]), |
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| 314 | .mcr (mcr[4:0]), |
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| 315 | .lcr (lcr[7:0]), |
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| 316 | .msr (msr[7:0]), |
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| 317 | .lsr (lsr[7:0]), |
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| 318 | .rf_count (rf_count[`UART_FIFO_COUNTER_W-1:0]), |
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| 319 | .tf_count (tf_count[`UART_FIFO_COUNTER_W-1:0]), |
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| 320 | .tstate (tstate[2:0]), |
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| 321 | .rstate (rstate[3:0])); |
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| 322 | `endif |
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| 323 | |
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| 324 | initial |
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| 325 | begin |
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| 326 | `ifdef DATA_BUS_WIDTH_8 |
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| 327 | $display("(%m) UART INFO: Data bus width is 8. No Debug interface.\n"); |
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| 328 | `else |
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| 329 | $display("(%m) UART INFO: Data bus width is 32. Debug Interface present.\n"); |
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| 330 | `endif |
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| 331 | `ifdef UART_HAS_BAUDRATE_OUTPUT |
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| 332 | $display("(%m) UART INFO: Has baudrate output\n"); |
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| 333 | `else |
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| 334 | $display("(%m) UART INFO: Doesn't have baudrate output\n"); |
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| 335 | `endif |
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| 336 | end |
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| 337 | |
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| 338 | endmodule |
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| 339 | |
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| 340 | |
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