1 | -- |
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2 | -- Project: Aurora Module Generator version 2.4 |
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3 | -- |
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4 | -- Date: $Date: 2005/11/07 21:30:56 $ |
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5 | -- Tag: $Name: i+IP+98818 $ |
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6 | -- File: $RCSfile: tx_ll_datapath_vhd.ejava,v $ |
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7 | -- Rev: $Revision: 1.1.2.4 $ |
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8 | -- |
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9 | -- Company: Xilinx |
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10 | -- Contributors: R. K. Awalt, B. L. Woodard, N. Gulstone |
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11 | -- |
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12 | -- Disclaimer: XILINX IS PROVIDING THIS DESIGN, CODE, OR |
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13 | -- INFORMATION "AS IS" SOLELY FOR USE IN DEVELOPING |
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14 | -- PROGRAMS AND SOLUTIONS FOR XILINX DEVICES. BY |
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15 | -- PROVIDING THIS DESIGN, CODE, OR INFORMATION AS |
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16 | -- ONE POSSIBLE IMPLEMENTATION OF THIS FEATURE, |
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17 | -- APPLICATION OR STANDARD, XILINX IS MAKING NO |
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18 | -- REPRESENTATION THAT THIS IMPLEMENTATION IS FREE |
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19 | -- FROM ANY CLAIMS OF INFRINGEMENT, AND YOU ARE |
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20 | -- RESPONSIBLE FOR OBTAINING ANY RIGHTS YOU MAY |
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21 | -- REQUIRE FOR YOUR IMPLEMENTATION. XILINX |
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22 | -- EXPRESSLY DISCLAIMS ANY WARRANTY WHATSOEVER WITH |
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23 | -- RESPECT TO THE ADEQUACY OF THE IMPLEMENTATION, |
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24 | -- INCLUDING BUT NOT LIMITED TO ANY WARRANTIES OR |
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25 | -- REPRESENTATIONS THAT THIS IMPLEMENTATION IS FREE |
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26 | -- FROM CLAIMS OF INFRINGEMENT, IMPLIED WARRANTIES |
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27 | -- OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
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28 | -- PURPOSE. |
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29 | -- |
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30 | -- (c) Copyright 2004 Xilinx, Inc. |
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31 | -- All rights reserved. |
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32 | -- |
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33 | |
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34 | -- |
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35 | -- TX_LL_DATAPATH |
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36 | -- |
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37 | -- Author: Nigel Gulstone |
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38 | -- Xilinx - Embedded Networking System Engineering Group |
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39 | -- |
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40 | -- Description: This module pipelines the data path while handling the PAD |
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41 | -- character placement and valid data flags. |
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42 | -- |
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43 | -- This module supports 1 2-byte lane designs |
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44 | -- |
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45 | |
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46 | library IEEE; |
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47 | use IEEE.STD_LOGIC_1164.all; |
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48 | |
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49 | entity TX_LL_DATAPATH is |
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50 | |
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51 | port ( |
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52 | |
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53 | -- LocalLink PDU Interface |
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54 | |
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55 | TX_D : in std_logic_vector(0 to 15); |
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56 | TX_REM : in std_logic; |
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57 | TX_SRC_RDY_N : in std_logic; |
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58 | TX_SOF_N : in std_logic; |
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59 | TX_EOF_N : in std_logic; |
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60 | |
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61 | -- Aurora Lane Interface |
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62 | |
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63 | TX_PE_DATA_V : out std_logic; |
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64 | GEN_PAD : out std_logic; |
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65 | TX_PE_DATA : out std_logic_vector(0 to 15); |
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66 | |
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67 | -- TX_LL Control Module Interface |
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68 | |
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69 | HALT_C : in std_logic; |
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70 | TX_DST_RDY_N : in std_logic; |
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71 | |
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72 | -- System Interface |
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73 | |
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74 | CHANNEL_UP : in std_logic; |
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75 | USER_CLK : in std_logic |
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76 | |
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77 | ); |
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78 | |
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79 | end TX_LL_DATAPATH; |
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80 | |
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81 | architecture RTL of TX_LL_DATAPATH is |
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82 | |
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83 | -- Parameter Declarations -- |
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84 | |
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85 | constant DLY : time := 1 ns; |
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86 | |
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87 | -- External Register Declarations -- |
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88 | |
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89 | signal TX_PE_DATA_V_Buffer : std_logic; |
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90 | signal GEN_PAD_Buffer : std_logic; |
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91 | signal TX_PE_DATA_Buffer : std_logic_vector(0 to 15); |
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92 | |
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93 | -- Internal Register Declarations -- |
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94 | |
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95 | signal in_frame_r : std_logic; |
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96 | signal storage_r : std_logic_vector(0 to 15); |
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97 | signal storage_v_r : std_logic; |
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98 | signal storage_pad_r : std_logic; |
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99 | signal tx_pe_data_r : std_logic_vector(0 to 15); |
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100 | signal valid_c : std_logic; |
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101 | signal tx_pe_data_v_r : std_logic; |
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102 | signal gen_pad_c : std_logic; |
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103 | signal gen_pad_r : std_logic; |
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104 | |
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105 | -- Internal Wire Declarations -- |
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106 | |
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107 | signal ll_valid_c : std_logic; |
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108 | signal in_frame_c : std_logic; |
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109 | |
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110 | begin |
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111 | |
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112 | TX_PE_DATA_V <= TX_PE_DATA_V_Buffer; |
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113 | GEN_PAD <= GEN_PAD_Buffer; |
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114 | TX_PE_DATA <= TX_PE_DATA_Buffer; |
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115 | |
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116 | -- Main Body of Code -- |
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117 | |
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118 | |
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119 | |
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120 | -- LocalLink input is only valid when TX_SRC_RDY_N and TX_DST_RDY_N are both asserted |
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121 | ll_valid_c <= not TX_SRC_RDY_N and not TX_DST_RDY_N; |
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122 | |
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123 | |
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124 | -- Data must only be read if it is within a frame. If a frame will last multiple cycles |
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125 | -- we assert in_frame_r as long as the frame is open. |
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126 | process(USER_CLK) |
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127 | begin |
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128 | if(USER_CLK'event and USER_CLK = '1') then |
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129 | if(CHANNEL_UP = '0') then |
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130 | in_frame_r <= '0' after DLY; |
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131 | elsif(ll_valid_c = '1') then |
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132 | if( (TX_SOF_N = '0') and (TX_EOF_N = '1') ) then |
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133 | in_frame_r <= '1' after DLY; |
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134 | elsif( TX_EOF_N = '0') then |
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135 | in_frame_r <= '0' after DLY; |
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136 | end if; |
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137 | end if; |
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138 | end if; |
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139 | end process; |
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140 | |
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141 | |
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142 | in_frame_c <= ll_valid_c and (in_frame_r or not TX_SOF_N); |
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143 | |
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144 | |
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145 | |
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146 | |
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147 | |
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148 | -- The data from the LocalLink interface must be delayed one cycle to |
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149 | -- make room for the SCP code group in the channel. |
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150 | |
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151 | process (USER_CLK) |
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152 | |
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153 | begin |
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154 | |
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155 | if (USER_CLK 'event and USER_CLK = '1') then |
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156 | |
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157 | if (HALT_C = '0') then |
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158 | |
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159 | storage_r <= TX_D after DLY; |
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160 | |
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161 | end if; |
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162 | |
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163 | end if; |
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164 | |
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165 | end process; |
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166 | |
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167 | |
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168 | -- This pipeline register aligns the data with the control path. |
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169 | |
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170 | process (USER_CLK) |
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171 | |
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172 | begin |
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173 | |
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174 | if (USER_CLK 'event and USER_CLK = '1') then |
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175 | |
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176 | if (HALT_C = '0') then |
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177 | |
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178 | tx_pe_data_r <= storage_r after DLY; |
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179 | |
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180 | end if; |
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181 | |
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182 | end if; |
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183 | |
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184 | end process; |
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185 | |
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186 | |
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187 | -- We generate the valid_c signal based on the REM signal and the EOF signal. |
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188 | |
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189 | process (TX_EOF_N, TX_REM) |
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190 | |
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191 | begin |
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192 | |
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193 | if (TX_EOF_N = '1') then |
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194 | |
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195 | valid_c <= '1'; |
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196 | |
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197 | else |
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198 | |
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199 | case TX_REM is |
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200 | |
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201 | when '0' => valid_c <= '1'; |
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202 | when '1' => valid_c <= '1'; |
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203 | when others => valid_c <= '1'; |
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204 | |
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205 | end case; |
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206 | |
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207 | end if; |
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208 | |
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209 | end process; |
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210 | |
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211 | |
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212 | -- If the word is valid, it is placed in the storage register and storage_v_r is |
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213 | -- asserted to indicate the data is valid. Note that data is only moved to storage |
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214 | -- if the PDU datapath is not halted, the data is valid and both TX_SRC_RDY_N and |
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215 | -- TX_DST_RDY_N are asserted. |
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216 | |
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217 | process (USER_CLK) |
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218 | |
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219 | begin |
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220 | |
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221 | if (USER_CLK 'event and USER_CLK = '1') then |
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222 | |
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223 | if (HALT_C = '0') then |
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224 | |
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225 | storage_v_r <= valid_c and in_frame_c after DLY; |
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226 | |
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227 | end if; |
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228 | |
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229 | end if; |
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230 | |
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231 | end process; |
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232 | |
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233 | |
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234 | -- Register the tx_pe_data_valid signal. All data is moved from the storage register |
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235 | -- to the tx_pe_data register for transmission when the datapath is not halted. If the |
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236 | -- storage register contains valid PDU data, the tx_pe_data register is marked as |
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237 | -- containing valid PDU data |
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238 | |
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239 | process (USER_CLK) |
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240 | |
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241 | begin |
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242 | |
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243 | if (USER_CLK 'event and USER_CLK = '1') then |
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244 | |
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245 | if (HALT_C = '0') then |
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246 | |
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247 | tx_pe_data_v_r <= storage_v_r after DLY; |
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248 | |
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249 | end if; |
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250 | |
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251 | end if; |
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252 | |
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253 | end process; |
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254 | |
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255 | |
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256 | -- We generate the gen_pad_c signal based on the REM signal and the EOF signal. |
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257 | |
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258 | process (TX_EOF_N, TX_REM) |
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259 | |
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260 | begin |
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261 | |
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262 | if (TX_EOF_N = '1') then |
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263 | |
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264 | gen_pad_c <= '0'; |
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265 | |
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266 | else |
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267 | |
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268 | case TX_REM is |
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269 | |
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270 | when '0' => gen_pad_c <= '1'; |
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271 | when '1' => gen_pad_c <= '0'; |
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272 | when others => gen_pad_c <= '0'; |
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273 | |
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274 | end case; |
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275 | |
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276 | end if; |
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277 | |
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278 | end process; |
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279 | |
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280 | |
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281 | -- Store padded data when padded and TX_SRC_RDY_N and TX_DST_RDY_N are both asserted. |
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282 | |
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283 | process (USER_CLK) |
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284 | |
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285 | begin |
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286 | |
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287 | if (USER_CLK 'event and USER_CLK = '1') then |
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288 | |
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289 | if (HALT_C = '0') then |
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290 | |
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291 | storage_pad_r <= gen_pad_c and in_frame_c after DLY; |
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292 | |
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293 | end if; |
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294 | |
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295 | end if; |
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296 | |
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297 | end process; |
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298 | |
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299 | |
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300 | -- Register the gen_pad signal. |
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301 | |
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302 | process (USER_CLK) |
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303 | |
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304 | begin |
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305 | |
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306 | if (USER_CLK 'event and USER_CLK = '1') then |
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307 | |
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308 | if (HALT_C = '0') then |
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309 | |
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310 | gen_pad_r <= storage_pad_r after DLY; |
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311 | |
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312 | end if; |
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313 | |
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314 | end if; |
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315 | |
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316 | end process; |
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317 | |
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318 | |
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319 | -- Implement the data out register. |
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320 | |
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321 | process (USER_CLK) |
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322 | |
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323 | begin |
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324 | |
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325 | if (USER_CLK 'event and USER_CLK = '1') then |
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326 | |
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327 | TX_PE_DATA_Buffer <= tx_pe_data_r after DLY; |
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328 | TX_PE_DATA_V_Buffer <= tx_pe_data_v_r and not HALT_C after DLY; |
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329 | GEN_PAD_Buffer <= gen_pad_r and not HALT_C after DLY; |
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330 | |
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331 | end if; |
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332 | |
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333 | end process; |
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334 | |
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335 | |
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336 | end RTL; |
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