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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