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[/] [tcp_ip_core_w_dhcp/] [trunk/] [eth_mod.vhd] - Blame information for rev 2

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Line No. Rev Author Line
1 2 craighaywo 
----------------------------------------------------------------------------------
2 
-- Company:
3 
-- Engineer:
4 
--
5 
-- Create Date:    21:09:04 12/10/2014
6 
-- Design Name:
7 
-- Module Name:    eth_mod - Behavioral
8 
-- Project Name:
9 
-- Target Devices:
10 
-- Tool versions:
11 
-- Description:
12 
--
13 
-- Dependencies:
14 
--
15 
-- Revision:
16 
-- Revision 0.01 - File Created
17 
-- Additional Comments:
18 
--
19 
-- TODO: Have 'G_ENABLE_DHCP' Generic and comment all statements that rely on dhcp with '#ifdef end'
20 
-- TODO: Get correct version of 'sf.conf' and add it to repository
21 
--
22 
----------------------------------------------------------------------------------
23 
 
24 
library IEEE;
25 
use IEEE.STD_LOGIC_1164.ALL;
26 
use IEEE.NUMERIC_STD.ALL;
27 
 
28 
-- Uncomment the following library declaration if instantiating
29 
-- any Xilinx primitives in this code.
30 
--library UNISIM;
31 
--use UNISIM.VComponents.all;
32 
 
33 
entity eth_mod is
34 
        Generic ( G_FUNCTION    :string :="client" );
35 
    Port (
36 
                        CLK_IN          : in STD_LOGIC;
37 
                        CLK_1HZ_IN      : in STD_LOGIC;
38 
 
39 
                        -- Command interface
40 
                        INIT_ENC28J60   : in    STD_LOGIC;
41 
                        DHCP_CONNECT    : in    STD_LOGIC;
42 
                        ERROR_OUT               : out  STD_LOGIC_VECTOR (7 downto 0);
43 
 
44 
                        -- Debug Interface
45 
                        DEBUG_IN                : in    STD_LOGIC_VECTOR(2 downto 0);
46 
                        DEBUG_OUT               : out  STD_LOGIC_VECTOR (15 downto 0);
47 
 
48 
                        -- TCP Connection Interface
49 
                        TCP_CONNECTION_ACTIVE_OUT       : out STD_LOGIC;
50 
                        TCP_RD_DATA_AVAIL_OUT           : out STD_LOGIC;
51 
                        TCP_RD_DATA_EN_IN                       : in STD_LOGIC;
52 
                        TCP_RD_DATA_OUT                         : out STD_LOGIC_VECTOR (7 downto 0);
53 
                        TCP_WR_DATA_POSSIBLE_OUT        : out STD_LOGIC;
54 
                        TCP_WR_DATA_EN_IN                       : in STD_LOGIC;
55 
                        TCP_WR_DATA_FLUSH_IN            : in STD_LOGIC;
56 
                        TCP_WR_DATA_IN                          : in STD_LOGIC_VECTOR (7 downto 0);
57 
 
58 
                        -- Eth SPI interface
59 
                        SDI_OUT         : out  STD_LOGIC;
60 
                        SDO_IN          : in  STD_LOGIC;
61 
                        SCLK_OUT        : out  STD_LOGIC;
62 
                        CS_OUT          : out  STD_LOGIC );
63 
end eth_mod;
64 
 
65 
architecture Behavioral of eth_mod is
66 
 
67 
        COMPONENT spi_mod
68 
                Port (  CLK_IN                          : in  STD_LOGIC;
69 
                                        RST_IN                          : in  STD_LOGIC;
70 
 
71 
                                        WR_CONTINUOUS_IN        : in  STD_LOGIC;
72 
                                        WE_IN                           : in  STD_LOGIC;
73 
                                        WR_ADDR_IN                      : in    STD_LOGIC_VECTOR (7 downto 0);
74 
                                        WR_DATA_IN                      : in  STD_LOGIC_VECTOR (7 downto 0);
75 
                                        WR_DATA_CMPLT_OUT       : out STD_LOGIC;
76 
 
77 
                                        RD_CONTINUOUS_IN                                : in  STD_LOGIC;
78 
                                        RD_IN                                   : in    STD_LOGIC;
79 
                                        RD_WIDTH_IN             : in  STD_LOGIC;
80 
                                        RD_ADDR_IN                      : in  STD_LOGIC_VECTOR (7 downto 0);
81 
                                        RD_DATA_OUT             : out STD_LOGIC_VECTOR (7 downto 0);
82 
                                        RD_DATA_CMPLT_OUT       : out STD_LOGIC;
83 
 
84 
                                        SLOW_CS_EN_IN                     : in STD_LOGIC;
85 
                                        OPER_CMPLT_POST_CS_OUT : out STD_LOGIC;
86 
 
87 
                                        SDI_OUT                         : out STD_LOGIC;
88 
                                        SDO_IN                          : in    STD_LOGIC;
89 
                                        SCLK_OUT                                : out STD_LOGIC;
90 
                                        CS_OUT                          : out STD_LOGIC);
91 
        END COMPONENT;
92 
 
93 
        COMPONENT checksum_calc
94 
    Port ( CLK_IN                                               : in  STD_LOGIC;
95 
           RST_IN                                               : in  STD_LOGIC;
96 
           CHECKSUM_CALC_IN                     : in  STD_LOGIC;
97 
           START_ADDR_IN                                : in  STD_LOGIC_VECTOR (10 downto 0);
98 
           COUNT_IN                                             : in  STD_LOGIC_VECTOR (10 downto 0);
99 
           VALUE_IN                                             : in  STD_LOGIC_VECTOR (7 downto 0);
100 
           VALUE_ADDR_OUT                               : out  STD_LOGIC_VECTOR (10 downto 0);
101 
                          CHECKSUM_INIT_IN                      : in  STD_LOGIC_VECTOR (15 downto 0);
102 
                          CHECKSUM_SET_INIT_IN          : in  STD_LOGIC;
103 
                          CHECKSUM_ODD_LENGTH_IN        : in  STD_LOGIC;
104 
           CHECKSUM_OUT                                 : out STD_LOGIC_VECTOR (15 downto 0);
105 
           CHECKSUM_DONE_OUT                    : out STD_LOGIC);
106 
        END COMPONENT;
107 
 
108 
        COMPONENT TCP_FIFO
109 
          PORT (
110 
                 clk                            : IN STD_LOGIC;
111 
                 din                            : IN STD_LOGIC_VECTOR(7 DOWNTO 0);
112 
                 wr_en                  : IN STD_LOGIC;
113 
                 rd_en                  : IN STD_LOGIC;
114 
                 dout                   : OUT STD_LOGIC_VECTOR(7 DOWNTO 0);
115 
                 full                   : OUT STD_LOGIC;
116 
                 almost_full    : OUT STD_LOGIC;
117 
                 empty                  : OUT STD_LOGIC;
118 
                 data_count     : OUT STD_LOGIC_VECTOR(11 DOWNTO 0));
119 
        END COMPONENT;
120 
 
121 
        COMPONENT lfsr32_mod
122 
                 Port ( CLK_IN          : in  STD_LOGIC;
123 
                                  SEED_IN               : in  STD_LOGIC_VECTOR(31 downto 0);
124 
                                  SEED_EN_IN    : in  STD_LOGIC;
125 
                                  VAL_OUT               : out STD_LOGIC_VECTOR(31 downto 0));
126 
        END COMPONENT;
127 
 
128 
        COMPONENT TDP_RAM
129 
                Generic (G_DATA_A_SIZE  :natural :=32;
130 
                                        G_ADDR_A_SIZE   :natural :=9;
131 
                                        G_RELATION              :natural :=3;
132 
                                        G_INIT_ZERO             :boolean := true;
133 
                                        G_INIT_FILE             :string :="");--log2(SIZE_A/SIZE_B)
134 
                Port ( CLK_A_IN         : in  STD_LOGIC;
135 
                                 WE_A_IN        : in  STD_LOGIC;
136 
                                 ADDR_A_IN      : in  STD_LOGIC_VECTOR (G_ADDR_A_SIZE-1 downto 0);
137 
                                 DATA_A_IN      : in  STD_LOGIC_VECTOR (G_DATA_A_SIZE-1 downto 0);
138 
                                 DATA_A_OUT     : out  STD_LOGIC_VECTOR (G_DATA_A_SIZE-1 downto 0);
139 
                                 CLK_B_IN       : in  STD_LOGIC;
140 
                                 WE_B_IN        : in  STD_LOGIC;
141 
                                 ADDR_B_IN      : in  STD_LOGIC_VECTOR (G_ADDR_A_SIZE+G_RELATION-1 downto 0);
142 
                                 DATA_B_IN      : in  STD_LOGIC_VECTOR (G_DATA_A_SIZE/(2**G_RELATION)-1 downto 0);
143 
                                 DATA_B_OUT : out STD_LOGIC_VECTOR (G_DATA_A_SIZE/(2**G_RELATION)-1 downto 0));
144 
        END COMPONENT;
145 
 
146 
        COMPONENT Packet_Definition
147 
          PORT (
148 
                 clka   : IN STD_LOGIC;
149 
                 addra  : IN STD_LOGIC_VECTOR(10 DOWNTO 0);
150 
                 douta  : OUT STD_LOGIC_VECTOR(15 DOWNTO 0));
151 
        END COMPONENT;
152 
 
153 
subtype slv is std_logic_vector;
154 
 
155 
constant C_250us        : unsigned(15 downto 0) := X"61A8";
156 
constant C_200ms        : unsigned(24 downto 0) := '1'&X"312D00";
157 
constant C_100ms        : unsigned(23 downto 0) := X"989680";
158 
constant C_20ms         : unsigned(20 downto 0) := '1'&X"E8480";
159 
 
160 
constant C_init_cmnds_start_addr        : std_logic_vector(7 downto 0) := X"01";
161 
constant C_init_cmnds_max_addr          : std_logic_vector(7 downto 0) := X"7F";
162 
 
163 
constant C_arp_reply_frame_addr                         : std_logic_vector(10 downto 0) := "000"&X"80";
164 
constant C_icmp_reply_frame_addr                : std_logic_vector(10 downto 0) := "000"&X"AB";
165 
constant C_dhcp_discover_frame_addr     : std_logic_vector(10 downto 0) := "001"&X"24";
166 
constant C_dhcp_request_frame_addr              : std_logic_vector(10 downto 0) := "010"&X"86";
167 
constant C_arp_request_frame_addr               : std_logic_vector(10 downto 0) := "100"&X"67";
168 
constant C_tcp_packet_frame_addr                : std_logic_vector(10 downto 0) := "100"&X"92";
169 
constant C_tcp_tx_packet_frame_addr     : std_logic_vector(10 downto 0) := "100"&X"F4";
170 
 
171 
constant C_arp_reply_length             : std_logic_vector(15 downto 0) := X"002A";
172 
constant C_icmp_reply_length            : std_logic_vector(15 downto 0) := X"0062";
173 
constant C_dhcp_discover_length         : std_logic_vector(15 downto 0) := X"0156";
174 
constant C_dhcp_request_length  : std_logic_vector(15 downto 0) := X"015C";
175 
constant C_arp_request_length   : std_logic_vector(15 downto 0) := X"002A";
176 
constant C_tcp_packet_length            : std_logic_vector(15 downto 0) := X"0042";
177 
 
178 
constant C_ARP_Packet_Type              : std_logic_vector(15 downto 0) := X"0806";
179 
constant C_IP_Packet_Type                       : std_logic_vector(15 downto 0) := X"0800";
180 
constant C_ICMP_Protocol_Number : std_logic_vector(7 downto 0) := X"01";
181 
constant C_UDP_Protocol_Number  : std_logic_vector(7 downto 0) := X"11";
182 
constant C_TCP_Protocol_Number  : std_logic_vector(7 downto 0) := X"06";
183 
constant C_IPV4_Protocol_Number : std_logic_vector(3 downto 0) := X"4";
184 
constant C_DHCP_Source_Port             : std_logic_vector(15 downto 0) := X"0043";
185 
constant C_DHCP_Dest_Port                       : std_logic_vector(15 downto 0) := X"0044";
186 
constant C_dhcp_magic_cookie            : std_logic_vector(31 downto 0) := X"63825363";
187 
 
188 
constant C_tcp_syn_ack_flags    : std_logic_vector(7 downto 0) := X"12";
189 
constant C_tcp_syn_flags                        : std_logic_vector(7 downto 0) := X"02";
190 
 
191 
constant C_tcp_ack_flags                        : std_logic_vector(7 downto 0) := X"10";
192 
constant C_tcp_fin_ack_flags            : std_logic_vector(7 downto 0) := X"11";
193 
constant C_tcp_psh_ack_flags            : std_logic_vector(7 downto 0) := X"18";
194 
 
195 
constant C_ICMP_Ping_Length             : std_logic_vector(15 downto 0) := X"0054";
196 
constant C_ARP_Request                          : std_logic_vector(7 downto 0) := X"01";
197 
constant C_ARP_Reply                                    : std_logic_vector(7 downto 0) := X"02";
198 
 
199 
constant C_rx_pointer_min : unsigned(15 downto 0) := X"0000";
200 
constant C_rx_pointer_max : unsigned(15 downto 0) := X"0FFF";
201 
constant C_tx_base_addr1  : unsigned(15 downto 0) := X"1000";
202 
constant C_tx_base_addr2  : unsigned(15 downto 0) := X"1800";
203 
 
204 
signal spi_we, spi_wr_continuous, spi_wr_cmplt, spi_rd_continuous : std_logic := '0';
205 
signal spi_rd, spi_rd_width, spi_rd_cmplt, spi_oper_cmplt : std_logic := '0';
206 
signal spi_wr_addr, spi_wr_data, spi_rd_addr, spi_data_rd : std_logic_vector(7 downto 0) := (others => '0');
207 
 
208 
signal frame_addr : std_logic_vector(10 downto 0);
209 
signal frame_data : std_logic_vector(15 downto 0);
210 
signal frame_data_rd, frame_rd_cmplt, slow_cs_en : std_logic := '0';
211 
signal network_interface_enabled : std_logic := '0';
212 
 
213 
signal command_cmplt, command_trig, command_en_in_p     : std_logic := '0';
214 
signal init_cmnd_addr   : unsigned(7 downto 0);
215 
 
216 
signal interrupt_counter                        : unsigned(15 downto 0) := (others => '0');
217 
signal next_packet_pointer                      : std_logic_vector(15 downto 0) := (others => '0');
218 
signal previous_packet_pointer  : unsigned(15 downto 0) := (others => '0');
219 
signal eir_register                                     : std_logic_vector(7 downto 0) := (others => '0');
220 
 
221 
signal rx_packet_ram_we, handle_rx_packet, rx_packet_handled : std_logic := '0';
222 
signal debug_rx_flag, debug_rx_flag1, debug_rx_flag2  : std_logic := '0';
223 
signal rx_packet_ram_we_addr, rx_packet_ram_we_addr_buf : unsigned(10 downto 0) := (others => '0');
224 
signal rx_packet_ram_rd_addr : unsigned(10 downto 0) := (others => '0');
225 
signal rx_packet_rd2_addr : unsigned(10 downto 0) := (others => '0');
226 
signal rx_packet_rd_data, rx_packet_rd_data2 : std_logic_vector(7 downto 0);
227 
signal rx_packet_status_vector, arp_target_ip_addr, arp_source_ip_addr : std_logic_vector(31 downto 0);
228 
signal rx_packet_type                   : std_logic_vector(15 downto 0);
229 
signal rx_packet_source_mac     : std_logic_vector(47 downto 0);
230 
signal send_arp_reply, send_arp_request : std_logic := '0';
231 
signal send_icmp_reply, send_dhcp_discover, send_dhcp_request : std_logic := '0';
232 
signal arp_opcode : std_logic_vector(7 downto 0);
233 
 
234 
signal tx_packet_ram_we, tx_packet_config_cmplt : std_logic := '0';
235 
signal tx_packet_ram_we_addr, tx_packet_ram_rd_addr : unsigned(10 downto 0) := (others => '0');
236 
signal tx_packet_ram_we_addr_buf : unsigned(10 downto 0) := (others => '0');
237 
signal tx_packet_rd_data, tx_packet_ram_data : std_logic_vector(7 downto 0);
238 
signal tx_packet_rd_data2 : std_logic_vector(7 downto 0);
239 
signal handle_tx_packet : std_logic := '0';
240 
 
241 
signal ip_addr                          : std_logic_vector(31 downto 0) := X"C0A80166";          -- 192.168.1.102
242 
signal mac_addr                         : std_logic_vector(47 downto 0) := X"8066F23D547A";
243 
signal ip_identification        : std_logic_vector(15 downto 0);
244 
signal ping_enable                      : std_logic := '1';
245 
signal dhcp_enable                      : std_logic := '0';
246 
signal dhcp_addr_locked, static_addr_locked     : std_logic := '0';
247 
 
248 
signal client_ip_addr : std_logic_vector(31 downto 0) := X"C0A80100";    -- 192.168.1.0 should be set dynamically upon TCP connection ??
249 
signal client_mac_addr : std_logic_vector(47 downto 0) := X"000000000000";
250 
 
251 
--signal cloud_ip_addr : std_logic_vector(31 downto 0) := X"76D2707C"; -- 118.210.112.124
252 
signal cloud_ip_addr : std_logic_vector(31 downto 0) := X"C0A80100"; -- 192.168.1.0
253 
 
254 
signal tx_packet_frame_addr :unsigned(10 downto 0);
255 
signal tx_packet_length, tx_packet_length_counter, tx_packet_end_pointer :unsigned(15 downto 0);
256 
signal prev_tx_packet_end_pointer :unsigned(15 downto 0);
257 
signal doing_tx_packet_config, tx_packet_frame_data_rd : std_logic := '0';
258 
signal packet_instruction, packet_data : std_logic_vector(7 downto 0);
259 
signal tx_packet_ready_for_transmission : std_logic := '0';
260 
signal send_prev_packet_waiting, trigger_send_prev_packet : std_logic := '0';
261 
signal trigger_close_connection, wait_for_tcp_window_size_update : std_logic := '0';
262 
signal tx_base_addr, tx_base_addr_prev : unsigned(15 downto 0);
263 
signal tx_base_addr_select : std_logic := '0';
264 
 
265 
signal ip_packet_version                        : std_logic_vector(3 downto 0);
266 
signal ip_packet_protocol                       : std_logic_vector(7 downto 0);
267 
signal ip_packet_header_length  : std_logic_vector(7 downto 0);
268 
signal ip_packet_destination_ip         : std_logic_vector(31 downto 0);
269 
signal ip_packet_length, ip_packet_length_debug                         : std_logic_vector(15 downto 0); -- TODO remove debug
270 
signal total_packet_length              : unsigned(15 downto 0);
271 
 
272 
signal lfsr_val : std_logic_vector(31 downto 0);
273 
signal calc_checksum, checksum_calc_done : std_logic := '0';
274 
signal checksum_start_addr, checksum_addr, checksum_wr_addr : std_logic_vector(10 downto 0);
275 
signal checksum_count : unsigned(10 downto 0);
276 
signal checksum : std_logic_vector(15 downto 0);
277 
signal checksum_initial_value : std_logic_vector(15 downto 0);
278 
signal checksum_set_initial_value, checksum_odd_length : std_logic;
279 
 
280 
signal command : std_logic_vector(3 downto 0);
281 
signal poll_interrupt_reg, command_waiting : std_logic;
282 
signal poll_counter : unsigned(3 downto 0) := (others => '1');
283 
 
284 
signal dhcp_transaction_id : std_logic_vector(31 downto 0) := X"CA805562";
285 
signal transaction_id_rd : std_logic_vector(31 downto 0) := X"00000000";
286 
 
287 
signal udp_source_port, udp_dest_port : std_logic_vector(15 downto 0);
288 
signal dhcp_your_ip_addr, dhcp_server_ip_addr, dhcp_magic_cookie : std_logic_vector(31 downto 0);
289 
 
290 
signal expecting_dhcp_offer, expecting_dhcp_ack, expecting_arp_reply : std_logic := '0';
291 
signal expecting_syn_ack, ack_required, trigger_ack : std_logic := '0';
292 
signal dhcp_option_addr : unsigned(10 downto 0);
293 
signal dhcp_option, dhcp_option_length, dhcp_message_type : std_logic_vector(7 downto 0);
294 
 
295 
signal packet_definition_addr : std_logic_vector(10 downto 0);
296 
signal packet_definition_data : std_logic_vector(15 downto 0);
297 
 
298 
signal client_port      : std_logic_vector(15 downto 0) := (others => '0');
299 
signal listen_port      : std_logic_vector(15 downto 0) := X"0DA2";
300 
signal tcp_sequence_number, tcp_acknowledge_number : unsigned(31 downto 0) := (others => '0');
301 
signal tcp_sequence_number_previous_ack, tcp_ack_number_previous_ack : unsigned(31 downto 0) := (others => '0');
302 
signal tcp_ack_number_previous_ack1, tcp_ack_number_previous_ack2, tcp_ack_number_previous_ack3 : unsigned(31 downto 0) := (others => '0');
303 
signal tcp_ack_number_previous_ack4, tcp_ack_number_previous_ack5, tcp_ack_number_previous_ack6 : unsigned(31 downto 0) := (others => '0');
304 
signal tcp_sequence_number_p1 : unsigned(31 downto 0) := (others => '0');
305 
signal tcp_flags : std_logic_vector(7 downto 0) := (others => '0');
306 
signal window_size : unsigned(11 downto 0) := X"E00";
307 
signal requested_data_size : unsigned(11 downto 0);
308 
signal send_tcp_ack_packet, cancel_dhcp_connect : std_logic := '0';
309 
signal send_tcp_tx_packet : std_logic := '0';
310 
signal tcp_connection_active, close_tcp_connection, cancel_tcp_connection : std_logic := '0';
311 
signal tcp_ip_identification : unsigned(15 downto 0);
312 
 
313 
signal rx_tcp_source_port, rx_tcp_dest_port : std_logic_vector(15 downto 0) := (others => '0');
314 
signal rx_tcp_seq_number, rx_tcp_ack_number : std_logic_vector(31 downto 0) := (others => '0');
315 
signal rx_tcp_window_size_shifted : std_logic_vector(31 downto 0) := (others => '0');
316 
signal rx_tcp_window_size, rx_tcp_checksum : std_logic_vector(15 downto 0) := (others => '0');
317 
signal rx_tcp_flags, rx_tcp_option, rx_tcp_header_length : std_logic_vector(7 downto 0) := (others => '0');
318 
signal rx_tcp_option_length : unsigned(7 downto 0);
319 
signal rx_tcp_window_shift : std_logic_vector(3 downto 0);
320 
signal tcp_option_addr, next_protocol_start_addr : unsigned(10 downto 0);
321 
signal rx_data_length, prev_rx_data_length : unsigned(15 downto 0);
322 
signal rx_data_start_addr : unsigned(10 downto 0);
323 
signal resend_ack_packet, fin_received, syn_ack_packet : std_logic := '0';
324 
signal sent_syn_ack : std_logic := '0';
325 
signal fin_received_p, trigger_fin_ack : std_logic := '0';
326 
 
327 
signal tcp_rx_data_we, tcp_rd_data_available, tcp_data_rd_en : std_logic := '0';
328 
signal tcp_rx_ram_almost_full : std_logic := '0';
329 
signal tcp_rd_data_count, tcp_wr_data_count     : std_logic_vector(11 downto 0) := (others => '0');
330 
signal tcp_rx_data                                                                      : unsigned(7 downto 0) := (others => '0');
331 
signal tcp_rx_data_rd_data                                              : std_logic_vector(7 downto 0) := (others => '0');
332 
 
333 
signal tcp_wr_data_possible, tcp_wr_data_en, tcp_tx_data_rd : std_logic := '0';
334 
signal tcp_wr_data_flush, tcp_data_flush_waiting : std_logic := '0';
335 
signal large_tx_packet_waiting : std_logic := '0';
336 
signal tcp_wr_data, tcp_tx_data : std_logic_vector(7 downto 0) := (others => '0');
337 
signal tx_bytes_to_send, tx_total_packet_length, tx_packet_data_counter : unsigned(11 downto 0) := (others => '0');
338 
signal tx_total_packet_length_inc_mac, tx_total_packet_length_checksum  : unsigned(11 downto 0) := (others => '0');
339 
signal tx_packet_no_ack_timeout : unsigned(23 downto 0) := C_100ms;
340 
signal tx_packet_timeout_counter, tx_packet_timeout_counter_prev : unsigned(7 downto 0) := X"00";
341 
signal tx_timeout_counter : unsigned(20 downto 0);
342 
signal tx_packets_no_ack : unsigned(3 downto 0) := X"0";
343 
 
344 
signal clk_1hz, clk_1hz_prev : std_logic := '0';
345 
signal init_enc28j60_waiting, dhcp_connect_waiting, tcp_connect_waiting : std_logic := '0';
346 
signal rx_kbytes_sec, tx_kbytes_sec : unsigned(11 downto 0);
347 
signal rx_bytes_counter, tx_bytes_counter : unsigned(21 downto 0);
348 
 
349 
signal ack_countdown : unsigned(15 downto 0);
350 
signal num_packets : std_logic_vector(7 downto 0) := (others => '0');
351 
 
352 
type ETH_ST is (        IDLE,
353 
                                                TRIGGER_DHCP_DISCOVER,
354 
                                                TRIGGER_ARP_REQUEST,
355 
                                                TRIGGER_CANCEL_DHCP_CONNECT,
356 
                                                TRIGGER_CLOSE_TCP_CONNECTION,
357 
                                                TRIGGER_CANCEL_TCP_CONNECTION,
358 
                                                HANDLE_INIT_CMND0,
359 
                                                HANDLE_INIT_CMND1,
360 
                                                HANDLE_INIT_CMND2,
361 
                                                HANDLE_INIT_CMND3,
362 
                                                HANDLE_INIT_CMND4,
363 
                                                HANDLE_INIT_CMND5,
364 
                                                HANDLE_INIT_CMND6,
365 
                                                SERVICE_INTERRUPT0,
366 
                                                SERVICE_INTERRUPT1,
367 
                                                SERVICE_INTERRUPT2,
368 
                                                SERVICE_INTERRUPT3,
369 
                                                SERVICE_INTERRUPT4,
370 
                                                SERVICE_INTERRUPT5,
371 
                                                SERVICE_INTERRUPT6,
372 
                                                SERVICE_INTERRUPT7,
373 
                                                SERVICE_INTERRUPT8,
374 
                                                HANDLE_TX_INTERRUPT0,
375 
                                                HANDLE_TX_INTERRUPT1,
376 
                                                HANDLE_TX_INTERRUPT2,
377 
                                                HANDLE_RX_INTERRUPT0,
378 
                                                HANDLE_RX_INTERRUPT1,
379 
                                                HANDLE_RX_INTERRUPT2,
380 
                                                HANDLE_RX_INTERRUPT3,
381 
                                                HANDLE_RX_INTERRUPT4,
382 
                                                HANDLE_RX_INTERRUPT5,
383 
                                                HANDLE_RX_INTERRUPT6,
384 
                                                HANDLE_RX_INTERRUPT7,
385 
                                                HANDLE_RX_INTERRUPT8,
386 
                                                HANDLE_RX_INTERRUPT9,
387 
                                                HANDLE_RX_INTERRUPT10,
388 
                                                HANDLE_RX_INTERRUPT11,
389 
                                                HANDLE_RX_INTERRUPT12,
390 
                                                HANDLE_RX_INTERRUPT13,
391 
                                                HANDLE_RX_INTERRUPT14,
392 
                                                HANDLE_RX_INTERRUPT15,
393 
                                                HANDLE_RX_INTERRUPT16,
394 
                                                HANDLE_RX_INTERRUPT17,
395 
                                                CHECK_IF_ACK_WAITING,
396 
                                                TRIGGER_ACK_PACKET,
397 
                                                TRIGGER_TCP_TX0,
398 
                                                TRIGGER_TCP_TX1,
399 
                                                TRIGGER_TCP_TX2,
400 
                                                COPY_RX_PACKET_TO_BUF0,
401 
                                                COPY_RX_PACKET_TO_BUF1,
402 
                                                COPY_RX_PACKET_TO_BUF2,
403 
                                                COPY_RX_PACKET_TO_BUF3,
404 
                                                COPY_RX_PACKET_TO_BUF4,
405 
                                                COPY_RX_PACKET_TO_BUF5,
406 
                                                COPY_RX_PACKET_TO_BUF6,
407 
                                                PRE_TX_TRANSMIT0,
408 
                                                PRE_TX_TRANSMIT1,
409 
                                                PRE_TX_TRANSMIT2,
410 
                                                PRE_TX_TRANSMIT3,
411 
                                                PRE_TX_TRANSMIT4,
412 
                                                PRE_TX_TRANSMIT5,
413 
                                                HANDLE_TX_TRANSMIT0,
414 
                                                HANDLE_TX_TRANSMIT1,
415 
                                                HANDLE_TX_TRANSMIT2,
416 
                                                HANDLE_TX_TRANSMIT3,
417 
                                                HANDLE_TX_TRANSMIT4,
418 
                                                HANDLE_TX_TRANSMIT5,
419 
                                                HANDLE_TX_TRANSMIT6,
420 
                                                HANDLE_TX_TRANSMIT7,
421 
                                                HANDLE_TX_TRANSMIT8,
422 
                                                HANDLE_TX_TRANSMIT9,
423 
                                                HANDLE_TX_TRANSMIT10,
424 
                                                HANDLE_TX_TRANSMIT_PRE11,
425 
                                                HANDLE_TX_TRANSMIT11,
426 
                                                HANDLE_TX_TRANSMIT12,
427 
                                                HANDLE_TX_TRANSMIT13,
428 
                                                HANDLE_TX_TRANSMIT14,
429 
                                                HANDLE_TX_TRANSMIT15,
430 
                                                HANDLE_TX_TRANSMIT16,
431 
                                                HANDLE_TX_TRANSMIT17,
432 
                                                HANDLE_TX_TRANSMIT18,
433 
                                                HANDLE_TX_TRANSMIT19,
434 
                                                HANDLE_TX_TRANSMIT20,
435 
                                                HANDLE_TX_TRANSMIT21,
436 
                                                HANDLE_TX_TRANSMIT22,
437 
                                                HANDLE_TX_TRANSMIT_PREV0,
438 
                                                HANDLE_TX_TRANSMIT_PREV1,
439 
                                                HANDLE_TX_TRANSMIT_PREV2,
440 
                                                HANDLE_TX_TRANSMIT_PREV3,
441 
                                                HANDLE_TX_TRANSMIT_PREV4,
442 
                                                HANDLE_TX_TRANSMIT_PREV5,
443 
                                                HANDLE_TX_TRANSMIT_PREV6,
444 
                                                HANDLE_TX_TRANSMIT_PREV7,
445 
                                                HANDLE_TX_TRANSMIT_PREV8,
446 
                                                HANDLE_TX_TRANSMIT_PREV9,
447 
                                                HANDLE_TX_TRANSMIT_PREV10,
448 
                                                HANDLE_TX_TRANSMIT_PREV11,
449 
                                                HANDLE_TX_TRANSMIT_PREV12,
450 
                                                HANDLE_TX_TRANSMIT_PREV13,
451 
                                                HANDLE_TX_TRANSMIT_PREV14,
452 
                                                HANDLE_TX_TRANSMIT_PREV15,
453 
                                                HANDLE_TX_TRANSMIT_PREV16,
454 
                                                WAIT_FOR_TRANSMIT_CMPLT,
455 
                                                RESEND_ACK_IN_BUFFER);
456 
 
457 
signal eth_state, eth_next_state : ETH_ST := IDLE;
458 
signal state_debug_sig : unsigned(7 downto 0);
459 
 
460 
type PACKET_HANDLER_ST is (     IDLE,
461 
                                                                                PARSE_SOURCE_MAC0,
462 
                                                                                PARSE_SOURCE_MAC1,
463 
                                                                                PARSE_SOURCE_MAC2,
464 
                                                                                PARSE_SOURCE_MAC3,
465 
                                                                                PARSE_SOURCE_MAC4,
466 
                                                                                PARSE_SOURCE_MAC5,
467 
                                                                                PARSE_SOURCE_MAC6,
468 
                                                                                PARSE_SOURCE_MAC7,
469 
                                                                                PARSE_PACKET_TYPE0,
470 
                                                                                PARSE_PACKET_TYPE1,
471 
                                                                                PARSE_PACKET_TYPE2,
472 
                                                                                PARSE_PACKET_TYPE3,
473 
                                                                                PARSE_PACKET_TYPE4,
474 
                                                                                HANDLE_ARP_PACKET0,
475 
                                                                                HANDLE_ARP_PACKET1,
476 
                                                                                HANDLE_ARP_PACKET2,
477 
                                                                                HANDLE_ARP_PACKET3,
478 
                                                                                HANDLE_ARP_REQUEST0,
479 
                                                                                HANDLE_ARP_REQUEST1,
480 
                                                                                HANDLE_ARP_REQUEST2,
481 
                                                                                HANDLE_ARP_REQUEST3,
482 
                                                                                HANDLE_ARP_REQUEST4,
483 
                                                                                HANDLE_ARP_REQUEST5,
484 
                                                                                HANDLE_ARP_REQUEST6,
485 
                                                                                HANDLE_ARP_REQUEST7,
486 
                                                                                HANDLE_ARP_REQUEST8,
487 
                                                                                HANDLE_ARP_REQUEST9,
488 
                                                                                HANDLE_ARP_REQUEST10,
489 
                                                                                HANDLE_ARP_REQUEST11,
490 
                                                                                HANDLE_ARP_REQUEST12,
491 
                                                                                HANDLE_ARP_REQUEST13,
492 
                                                                                HANDLE_ARP_REPLY0,
493 
                                                                                HANDLE_ARP_REPLY1,
494 
                                                                                HANDLE_ARP_REPLY2,
495 
                                                                                HANDLE_ARP_REPLY3,
496 
                                                                                HANDLE_ARP_REPLY4,
497 
                                                                                HANDLE_ARP_REPLY5,
498 
                                                                                HANDLE_ARP_REPLY6,
499 
                                                                                HANDLE_ARP_REPLY7,
500 
                                                                                TRIGGER_ARP_REPLY,
501 
                                                                                HANDLE_IP_PACKET0,
502 
                                                                                HANDLE_IP_PACKET1,
503 
                                                                                HANDLE_IP_PACKET2,
504 
                                                                                HANDLE_IP_PACKET3,
505 
                                                                                HANDLE_IP_PACKET4,
506 
                                                                                HANDLE_IP_PACKET5,
507 
                                                                                HANDLE_IP_PACKET6,
508 
                                                                                HANDLE_IP_PACKET7,
509 
                                                                                HANDLE_IP_PACKET8,
510 
                                                                                HANDLE_IP_PACKET9,
511 
                                                                                HANDLE_IP_PACKET10,
512 
                                                                                HANDLE_IP_PACKET11,
513 
                                                                                HANDLE_IP_PACKET12,
514 
                                                                                PRE_ICMP_PACKET_REPLY,
515 
                                                                                TRIGGER_ICMP_PACKET_REPLY,
516 
                                                                                PARSE_UDP_PACKET0,
517 
                                                                                PARSE_UDP_PACKET1,
518 
                                                                                PARSE_UDP_PACKET2,
519 
                                                                                PARSE_UDP_PACKET3,
520 
                                                                                PARSE_UDP_PACKET4,
521 
                                                                                PARSE_UDP_PACKET5,
522 
                                                                                PARSE_UDP_PACKET_TYPE0,
523 
                                                                                PARSE_UDP_PACKET_TYPE1,
524 
                                                                                PARSE_DHCP_PACKET0,
525 
                                                                                PARSE_DHCP_PACKET1,
526 
                                                                                PARSE_DHCP_PACKET2,
527 
                                                                                PARSE_DHCP_PACKET3,
528 
                                                                                PARSE_DHCP_PACKET4,
529 
                                                                                PARSE_DHCP_PACKET5,
530 
                                                                                PARSE_DHCP_PACKET6,
531 
                                                                                PARSE_DHCP_PACKET7,
532 
                                                                                PARSE_DHCP_PACKET8,
533 
                                                                                PARSE_DHCP_PACKET9,
534 
                                                                                PARSE_DHCP_PACKET10,
535 
                                                                                PARSE_DHCP_PACKET11,
536 
                                                                                PARSE_DHCP_PACKET12,
537 
                                                                                PARSE_DHCP_PACKET13,
538 
                                                                                PARSE_DHCP_PACKET14,
539 
                                                                                PARSE_DHCP_PACKET15,
540 
                                                                                PARSE_DHCP_PACKET16,
541 
                                                                                PARSE_DHCP_PACKET17,
542 
                                                                                PARSE_DHCP_PACKET18,
543 
                                                                                PARSE_DHCP_PACKET19,
544 
                                                                                PARSE_DHCP_PACKET20,
545 
                                                                                PARSE_DHCP_PACKET21,
546 
                                                                                PARSE_DHCP_PACKET22,
547 
                                                                                PARSE_DHCP_PACKET23,
548 
                                                                                PARSE_DHCP_PACKET24,
549 
                                                                                CHECK_OFFER_EXPECTED,
550 
                                                                                TRIGGER_DHCP_REQUEST,
551 
                                                                                HANDLE_DHCP_ACK0,
552 
                                                                                HANDLE_DHCP_ACK1,
553 
                                                                                HANDLE_DHCP_ACK2,
554 
                                                                                HANDLE_DHCP_ACK3,
555 
                                                                                HANDLE_DHCP_ACK4,
556 
                                                                                HANDLE_DHCP_ACK5,
557 
                                                                                HANDLE_DHCP_ACK6,
558 
                                                                                HANDLE_DHCP_ACK7,
559 
                                                                                HANDLE_DHCP_ACK8,
560 
                                                                                PARSE_TCP_PACKET0,
561 
                                                                                PARSE_TCP_PACKET1,
562 
                                                                                PARSE_TCP_PACKET2,
563 
                                                                                PARSE_TCP_PACKET3,
564 
                                                                                PARSE_TCP_PACKET4,
565 
                                                                                PARSE_TCP_PACKET5,
566 
                                                                                PARSE_TCP_PACKET6,
567 
                                                                                PARSE_TCP_PACKET7,
568 
                                                                                PARSE_TCP_PACKET8,
569 
                                                                                PARSE_TCP_PACKET9,
570 
                                                                                PARSE_TCP_PACKET10,
571 
                                                                                PARSE_TCP_PACKET11,
572 
                                                                                PARSE_TCP_PACKET12,
573 
                                                                                PARSE_TCP_PACKET13,
574 
                                                                                PARSE_TCP_PACKET14,
575 
                                                                                PARSE_TCP_PACKET15,
576 
                                                                                PARSE_TCP_PACKET16,
577 
                                                                                PARSE_TCP_PACKET17,
578 
                                                                                PARSE_TCP_PACKET18,
579 
                                                                                PARSE_TCP_PACKET19,
580 
                                                                                PARSE_TCP_PACKET20,
581 
                                                                                PARSE_TCP_PACKET21,
582 
                                                                                PARSE_TCP_PACKET22,
583 
                                                                                PARSE_TCP_PACKET23,
584 
                                                                                PARSE_TCP_PACKET24,
585 
                                                                                PARSE_TCP_PACKET25,
586 
                                                                                PARSE_TCP_PACKET26,
587 
                                                                                PARSE_TCP_PACKET27,
588 
                                                                                CHECK_TCP_SYN_PACKET0,
589 
                                                                                CHECK_TCP_SYN_PACKET1,
590 
                                                                                CHECK_TCP_SYN_PACKET2,
591 
                                                                                CHECK_TCP_SYN_PACKET3,
592 
                                                                                CHECK_TCP_SYN_PACKET4,
593 
                                                                                CHECK_TCP_SYN_PACKET5,
594 
                                                                                CHECK_TCP_PSH_ACK_PACKET0,
595 
                                                                                CHECK_TCP_PSH_ACK_PACKET1,
596 
                                                                                CHECK_TCP_PSH_ACK_PACKET2,
597 
                                                                                CHECK_TCP_PSH_ACK_PACKET3,
598 
                                                                                READ_TCP_RX_DATA,
599 
                                                                                TRIGGER_TCP_ACK0,
600 
                                                                                TRIGGER_TCP_ACK1,
601 
                                                                                TRIGGER_TCP_ACK2,
602 
                                                                                TRIGGER_TCP_ACK3,
603 
                                                                                RESEND_ACK,
604 
                                                                                CHECK_IF_DATA_TO_SEND,
605 
                                                                                TRIGGER_TCP_PSH_ACK0,
606 
                                                                                TRIGGER_TCP_PSH_ACK1,
607 
                                                                                CHECK_TCP_WINDOW_SIZE,
608 
                                                                                RX_TCP_WINDOW_TOO_SMALL,
609 
                                                                                TRIGGER_TCP_PSH_ACK2,
610 
                                                                                TRIGGER_TCP_PSH_ACK3,
611 
                                                                                COMPLETE
612 
                                                                        );
613 
 
614 
signal packet_handler_state, packet_handler_next_state : PACKET_HANDLER_ST := IDLE;
615 
 
616 
type TX_PACKET_CONFIG_ST is (   IDLE,
617 
                                                                                INIT_ARP_REPLY_METADATA,
618 
                                                                                INIT_ARP_REQUEST_METADATA,
619 
                                                                                INIT_ICMP_REPLY_METADATA,
620 
                                                                                INIT_DHCP_DISCOVER_METADATA,
621 
                                                                                INIT_DHCP_REQUEST_METADATA,
622 
                                                                                INIT_TCP_PACKET_METADATA,
623 
                                                                                INIT_TCP_TX_PACKET_METADATA,
624 
                                                                                CANCEL_DHCP_CONNECT_ST,
625 
                                                                                TCP_CONNECTION_CLOSED,
626 
                                                                                CANCEL_TCP_CONNECTION_ST,
627 
                                                                                READ_PACKET_BYTE0,
628 
                                                                                READ_PACKET_BYTE1,
629 
                                                                                HANDLE_PACKET_INSTRUCTION0,
630 
                                                                                HANDLE_PACKET_INSTRUCTION1,
631 
                                                                                SET_RX_PACKET_ADDR_LOWER_BYTE,
632 
                                                                                SET_RX_PACKET_ADDR_UPPER_BYTE,
633 
                                                                                SET_CHECKSUM_LENGTH_LSB,
634 
                                                                                SET_CHECKSUM_LENGTH_MSB,
635 
                                                                                SET_CHECKSUM_LENGTH_TX_PACKET_LENGTH0,
636 
                                                                                SET_CHECKSUM_LENGTH_TX_PACKET_LENGTH1,
637 
                                                                                SET_CHECKSUM_START_ADDR_LSB,
638 
                                                                                SET_CHECKSUM_START_ADDR_MSB,
639 
                                                                                SET_CHECKSUM_WR_ADDR_LSB,
640 
                                                                                SET_CHECKSUM_WR_ADDR_MSB,
641 
                                                                                MOVE_TX_PACKET_WR_ADDR,
642 
                                                                                SET_NEW_TRANSACTION_ID,
643 
                                                                                SET_CHECKSUM_START_VAL_LSB,
644 
                                                                                SET_CHECKSUM_START_VAL_MSB,
645 
                                                                                SET_CHECKSUM_INITIAL_VALUE_TX_PACKET,
646 
                                                                                TRIGGER_CHECKSUM_LOAD_INITIAL_VALUE,
647 
                                                                                TRIG_CHECKSUM_CALC,
648 
                                                                                WAIT_FOR_CHECKSUM_CMPLT,
649 
                                                                                INIT_LOAD_TX_PACKET_DATA,
650 
                                                                                LOAD_TX_PACKET_DATA,
651 
                                                                                COMPLETE
652 
                                                                        );
653 
 
654 
signal tx_packet_state, tx_packet_next_state : TX_PACKET_CONFIG_ST := IDLE;
655 
 
656 
begin
657 
 
658 
        --DEBUG_OUT(15 downto 8) <= X"00";
659 
        --DEBUG_OUT(15 downto 4) <= X"000";
660 
        --DEBUG_OUT(15 downto 12) <= (others => '0');
661 
        --DEBUG_OUT(15 downto 12) <= slv(interrupt_counter(3 downto 0));
662 
        --DEBUG_OUT <= slv(rx_data_length);
663 
        --DEBUG_OUT <= udp_source_port when DEBUG_IN = '0' else udp_dest_port;
664 
        --DEBUG_OUT <= rx_tcp_source_port when DEBUG_IN = '0' else rx_tcp_dest_port;
665 
        --DEBUG_OUT <= rx_tcp_window_size when DEBUG_IN(0) = '0' else X"000"&rx_tcp_window_shift;
666 
        --DEBUG_OUT <= rx_tcp_window_size_shifted(31 downto 16) when DEBUG_IN(0) = '0' else rx_tcp_window_size_shifted(15 downto 0);
667 
        --DEBUG_OUT(11 downto 0) <= slv(window_size);
668 
        --DEBUG_OUT(7 downto 0) <= slv(rx_tcp_option_length);
669 
        --DEBUG_OUT <= "00000"&slv(tcp_option_addr);
670 
        --DEBUG_OUT(7 downto 4) <= X"0";
671 
        --DEBUG_OUT(15 downto 8) <= ip_packet_protocol;
672 
        --DEBUG_OUT(15 downto 8) <= rx_tcp_option;
673 
        --DEBUG_OUT <= X"00" & slv(rx_tcp_option) when DEBUG_IN = '0' else rx_tcp_window_shift & slv(rx_tcp_option_length);
674 
        --DEBUG_OUT <= dhcp_option & dhcp_option_length;
675 
        --DEBUG_OUT(7 downto 0) <= slv(init_cmnd_addr);
676 
        --DEBUG_OUT(7 downto 0) <= slv(state_debug_sig);
677 
        --DEBUG_OUT(7 downto 0) <= slv(eir_register);
678 
        --DEBUG_OUT <= spi_wr_addr & spi_wr_data;
679 
        --DEBUG_OUT <= next_packet_pointer;
680 
        --DEBUG_OUT <= rx_packet_status_vector(15 downto 0) when DEBUG_IN = '0' else rx_packet_status_vector(31 downto 16);
681 
        --DEBUG_OUT <= rx_packet_source_mac(15 downto 0) when DEBUG_IN = '0' else rx_packet_source_mac(31 downto 16);
682 
        --DEBUG_OUT <= arp_target_ip_addr(15 downto 0) when DEBUG_IN = '0' else arp_target_ip_addr(31 downto 16);
683 
        --DEBUG_OUT <= arp_source_ip_addr(15 downto 0) when DEBUG_IN = '0' else arp_source_ip_addr(31 downto 16);
684 
        --DEBUG_OUT <= dhcp_your_ip_addr(15 downto 0) when DEBUG_IN = '0' else dhcp_your_ip_addr(31 downto 16);
685 
        --DEBUG_OUT <= slv(tcp_acknowledge_number(15 downto 0)) when DEBUG_IN(1) = '0' else slv(tcp_acknowledge_number(31 downto 16));
686 
        --DEBUG_OUT <= slv(tcp_ack_number_previous_ack(15 downto 0)) when DEBUG_IN = '0' else slv(tcp_ack_number_previous_ack(31 downto 16));
687 
        --DEBUG_OUT(11 downto 0) <= slv(requested_data_size);
688 
        --DEBUG_OUT(7 downto 0) <= tx_packet_rd_data;
689 
        --DEBUG_OUT <= rx_packet_type;
690 
        --DEBUG_OUT <= slv(tx_packet_end_pointer);
691 
        --DEBUG_OUT(3 downto 0) <= ip_packet_version;
692 
        --DEBUG_OUT(7 downto 0) <= X"0"&"0"&debug_rx_flag2&debug_rx_flag1&debug_rx_flag;
693 
        --DEBUG_OUT(7 downto 0) <= slv(num_packets);
694 
        --DEBUG_OUT(7 downto 0) <= slv(tcp_tx_data);
695 
        --DEBUG_OUT(3 downto 0) <= slv(tx_packet_ack_timeout_occur);
696 
        --DEBUG_OUT(11 downto 0) <= slv(rx_kbytes_sec);
697 
        DEBUG_OUT(15 downto 0) <= slv(interrupt_counter);
698 
        --DEBUG_OUT(15 downto 0) <= slv(tx_base_addr);
699 
        --DEBUG_OUT(15 downto 0) <= slv(checksum);
700 
        --DEBUG_OUT(15 downto 0) <= slv(checksum_initial_value);
701 
        --DEBUG_OUT(10 downto 0) <= slv(rx_data_start_addr);
702 
        --DEBUG_OUT(11 downto 0) <= slv(tcp_wr_data_count);
703 
 
704 
        packet_definition_addr <= frame_addr when doing_tx_packet_config = '0' else slv(tx_packet_frame_addr);
705 
        frame_data <= packet_definition_data;
706 
        frame_rd_cmplt <= '1';
707 
 
708 
        clk_1hz <= CLK_1HZ_IN;
709 
 
710 
        ---- HANDLE COMMANDS ----
711 
 
712 
        INT_PROC: process(CLK_IN)
713 
   begin
714 
      if rising_edge(CLK_IN) then
715 
                        if packet_handler_state = CHECK_TCP_SYN_PACKET0 then
716 
                                interrupt_counter <= interrupt_counter + 1;
717 
                        end if;
718 
                end if;
719 
        end process;
720 
 
721 
   SYNC_PROC: process(CLK_IN)
722 
   begin
723 
      if rising_edge(CLK_IN) then
724 
                        eth_state <= eth_next_state;
725 
      end if;
726 
   end process;
727 
 
728 
        NEXT_STATE_DECODE: process (eth_state, command, command_waiting, init_cmnd_addr, poll_interrupt_reg,
729 
                                                                                        frame_data, tx_packet_ready_for_transmission, spi_oper_cmplt,
730 
                                                                                                eir_register, previous_packet_pointer, next_packet_pointer, rx_packet_handled,
731 
                                                                                                        tx_packet_length_counter, spi_rd_cmplt, spi_wr_cmplt)
732 
   begin
733 
      eth_next_state <= eth_state;  --default is to stay in current state
734 
      case (eth_state) is
735 
         when IDLE =>
736 
                                if init_enc28j60_waiting = '1' then
737 
                                        eth_next_state <= HANDLE_INIT_CMND0;
738 
                                elsif dhcp_connect_waiting = '1' then
739 
                                        eth_next_state <= TRIGGER_DHCP_DISCOVER;
740 
                                elsif send_prev_packet_waiting = '1' then
741 
                                        eth_next_state <= HANDLE_TX_TRANSMIT_PREV0;
742 
                                elsif resend_ack_packet = '1' then
743 
                                        eth_next_state <= RESEND_ACK_IN_BUFFER;
744 
                                elsif tx_packet_ready_for_transmission = '1' then
745 
                                        eth_next_state <= PRE_TX_TRANSMIT0;
746 
                                elsif tcp_data_flush_waiting = '1' then
747 
                                        eth_next_state <= TRIGGER_TCP_TX0;
748 
                                elsif large_tx_packet_waiting = '1' then
749 
                                        eth_next_state <= TRIGGER_TCP_TX0;
750 
                                else
751 
                                        eth_next_state <= SERVICE_INTERRUPT0;
752 
                                end if;
753 
 
754 
                        when HANDLE_INIT_CMND0 =>
755 
                                eth_next_state <= HANDLE_INIT_CMND1;
756 
                        when HANDLE_INIT_CMND1 =>
757 
                                eth_next_state <= HANDLE_INIT_CMND2;
758 
                        when HANDLE_INIT_CMND2 =>
759 
                                if frame_rd_cmplt = '1' then
760 
                                        if frame_data = X"0000" then
761 
                                                eth_next_state <= HANDLE_INIT_CMND6;
762 
                                        else
763 
                                                eth_next_state <= HANDLE_INIT_CMND3;
764 
                                        end if;
765 
                                end if;
766 
                        when HANDLE_INIT_CMND3 =>
767 
                                eth_next_state <= HANDLE_INIT_CMND4;
768 
                        when HANDLE_INIT_CMND4 =>
769 
                                if spi_oper_cmplt = '1' then
770 
                                        eth_next_state <= HANDLE_INIT_CMND5;
771 
                                end if;
772 
                        when HANDLE_INIT_CMND5 =>
773 
                                if slv(init_cmnd_addr) = C_init_cmnds_max_addr then
774 
                                        eth_next_state <= HANDLE_INIT_CMND6;
775 
                                else
776 
                                        eth_next_state <= HANDLE_INIT_CMND1;
777 
                                end if;
778 
                        when HANDLE_INIT_CMND6 =>
779 
                                eth_next_state <= IDLE;
780 
 
781 
                        when TRIGGER_DHCP_DISCOVER =>
782 
                                eth_next_state <= IDLE;
783 
                        when TRIGGER_ARP_REQUEST =>
784 
                                eth_next_state <= IDLE;
785 
                        when TRIGGER_CANCEL_DHCP_CONNECT =>
786 
                                eth_next_state <= IDLE;
787 
                        when TRIGGER_CLOSE_TCP_CONNECTION =>
788 
                                eth_next_state <= IDLE;
789 
                        when TRIGGER_CANCEL_TCP_CONNECTION =>
790 
                                eth_next_state <= IDLE;
791 
 
792 
                        when SERVICE_INTERRUPT0 =>
793 
                                eth_next_state <= SERVICE_INTERRUPT1;
794 
                        when SERVICE_INTERRUPT1 =>
795 
                                if spi_oper_cmplt = '1' then
796 
                                        eth_next_state <= SERVICE_INTERRUPT2;
797 
                                end if;
798 
                        when SERVICE_INTERRUPT2 =>
799 
                                eth_next_state <= SERVICE_INTERRUPT3;
800 
                        when SERVICE_INTERRUPT3 =>
801 
                                if spi_oper_cmplt = '1' then
802 
                                        eth_next_state <= SERVICE_INTERRUPT4;
803 
                                end if;
804 
                        when SERVICE_INTERRUPT4 =>
805 
                                eth_next_state <= SERVICE_INTERRUPT5;
806 
                        when SERVICE_INTERRUPT5 =>
807 
                                if eir_register(6) = '1' then
808 
                                        eth_next_state <= HANDLE_RX_INTERRUPT0;
809 
                                elsif eir_register(3) = '1' then
810 
                                        eth_next_state <= HANDLE_TX_INTERRUPT0;
811 
                                else
812 
                                        eth_next_state <= SERVICE_INTERRUPT6;
813 
                                end if;
814 
                        when HANDLE_TX_INTERRUPT0 =>
815 
                                eth_next_state <= HANDLE_TX_INTERRUPT1;
816 
                        when HANDLE_TX_INTERRUPT1 =>
817 
                                if spi_oper_cmplt = '1' then
818 
                                        eth_next_state <= HANDLE_TX_INTERRUPT2;
819 
                                end if;
820 
                        when HANDLE_TX_INTERRUPT2 =>
821 
                                eth_next_state <= SERVICE_INTERRUPT6;
822 
                        when HANDLE_RX_INTERRUPT0 =>
823 
                                eth_next_state <= HANDLE_RX_INTERRUPT1;
824 
                        when HANDLE_RX_INTERRUPT1 =>
825 
                                if spi_oper_cmplt = '1' then
826 
                                        eth_next_state <= HANDLE_RX_INTERRUPT2;
827 
                                end if;
828 
                        when HANDLE_RX_INTERRUPT2 =>
829 
                                eth_next_state <= HANDLE_RX_INTERRUPT3;
830 
                        when HANDLE_RX_INTERRUPT3 =>
831 
                                if spi_oper_cmplt = '1' then
832 
                                        eth_next_state <= HANDLE_RX_INTERRUPT4;
833 
                                end if;
834 
                        when HANDLE_RX_INTERRUPT4 =>
835 
                                eth_next_state <= COPY_RX_PACKET_TO_BUF0;
836 
 
837 
                        when COPY_RX_PACKET_TO_BUF0 =>
838 
                                eth_next_state <= COPY_RX_PACKET_TO_BUF1;
839 
                        when COPY_RX_PACKET_TO_BUF1 =>
840 
                                eth_next_state <= COPY_RX_PACKET_TO_BUF2;
841 
                        when COPY_RX_PACKET_TO_BUF2 =>
842 
                                if spi_rd_cmplt = '1' then
843 
                                        eth_next_state <= COPY_RX_PACKET_TO_BUF3;
844 
                                end if;
845 
                        when COPY_RX_PACKET_TO_BUF3 =>
846 
                                eth_next_state <= COPY_RX_PACKET_TO_BUF4;
847 
                        when COPY_RX_PACKET_TO_BUF4 =>
848 
                                if slv(previous_packet_pointer) = next_packet_pointer then
849 
                                        eth_next_state <= COPY_RX_PACKET_TO_BUF5;
850 
                                else
851 
                                        eth_next_state <= COPY_RX_PACKET_TO_BUF1;
852 
                                end if;
853 
                        when COPY_RX_PACKET_TO_BUF5 =>
854 
                                if spi_oper_cmplt = '1' then
855 
                                        eth_next_state <= COPY_RX_PACKET_TO_BUF6;
856 
                                end if;
857 
                        when COPY_RX_PACKET_TO_BUF6 =>
858 
                                if rx_packet_handled = '1' then
859 
                                        eth_next_state <= HANDLE_RX_INTERRUPT5;
860 
                                end if;
861 
 
862 
                        when HANDLE_RX_INTERRUPT5 =>
863 
                                eth_next_state <= HANDLE_RX_INTERRUPT6;
864 
                        when HANDLE_RX_INTERRUPT6 =>
865 
                                if spi_oper_cmplt = '1' then
866 
                                        eth_next_state <= HANDLE_RX_INTERRUPT7;
867 
                                end if;
868 
                        when HANDLE_RX_INTERRUPT7 =>
869 
                                eth_next_state <= HANDLE_RX_INTERRUPT8;
870 
                        when HANDLE_RX_INTERRUPT8 =>
871 
                                if spi_oper_cmplt = '1' then
872 
                                        eth_next_state <= HANDLE_RX_INTERRUPT9;
873 
                                end if;
874 
                        when HANDLE_RX_INTERRUPT9 =>
875 
                                eth_next_state <= HANDLE_RX_INTERRUPT10;
876 
                        when HANDLE_RX_INTERRUPT10 =>
877 
                                if spi_oper_cmplt = '1' then
878 
                                        eth_next_state <= HANDLE_RX_INTERRUPT11;
879 
                                end if;
880 
                        when HANDLE_RX_INTERRUPT11 =>
881 
                                eth_next_state <= HANDLE_RX_INTERRUPT12;
882 
                        when HANDLE_RX_INTERRUPT12 =>
883 
                                if spi_oper_cmplt = '1' then
884 
                                        eth_next_state <= HANDLE_RX_INTERRUPT13;
885 
                                end if;
886 
                        when HANDLE_RX_INTERRUPT13 =>
887 
                                eth_next_state <= HANDLE_RX_INTERRUPT14;
888 
                        when HANDLE_RX_INTERRUPT14 =>
889 
                                if spi_oper_cmplt = '1' then
890 
                                        eth_next_state <= HANDLE_RX_INTERRUPT15;
891 
                                end if;
892 
                        when HANDLE_RX_INTERRUPT15 =>
893 
                                eth_next_state <= HANDLE_RX_INTERRUPT16;
894 
                        when HANDLE_RX_INTERRUPT16 =>
895 
                                if spi_oper_cmplt = '1' then
896 
                                        eth_next_state <= HANDLE_RX_INTERRUPT17;
897 
                                end if;
898 
                        when HANDLE_RX_INTERRUPT17 =>
899 
                                eth_next_state <= SERVICE_INTERRUPT6;
900 
 
901 
                        when CHECK_IF_ACK_WAITING =>
902 
                                if ack_required = '1' then
903 
                                        eth_next_state <= TRIGGER_ACK_PACKET;
904 
                                else
905 
                                        eth_next_state <= IDLE;
906 
                                end if;
907 
                        when TRIGGER_ACK_PACKET =>
908 
                                if packet_handler_state = TRIGGER_TCP_ACK0 then
909 
                                        eth_next_state <= IDLE;
910 
                                end if;
911 
 
912 
                        when TRIGGER_TCP_TX0 =>
913 
                                if tcp_wr_data_count = X"000" or tx_packets_no_ack > X"1" then
914 
                                        eth_next_state <= IDLE;
915 
                                else
916 
                                        eth_next_state <= TRIGGER_TCP_TX1;
917 
                                end if;
918 
                        when TRIGGER_TCP_TX1 =>
919 
                                if packet_handler_state = RX_TCP_WINDOW_TOO_SMALL then
920 
                                        eth_next_state <= IDLE;
921 
                                elsif packet_handler_state = TRIGGER_TCP_PSH_ACK2 then
922 
                                        eth_next_state <= TRIGGER_TCP_TX2;
923 
                                end if;
924 
                        when TRIGGER_TCP_TX2 =>
925 
                                if tx_packet_ready_for_transmission = '1' then
926 
                                        eth_next_state <= PRE_TX_TRANSMIT0;
927 
                                end if;
928 
 
929 
                        when SERVICE_INTERRUPT6 =>
930 
                                eth_next_state <= SERVICE_INTERRUPT7;
931 
                        when SERVICE_INTERRUPT7 =>
932 
                                if spi_oper_cmplt = '1' then
933 
                                        eth_next_state <= SERVICE_INTERRUPT8;
934 
                                end if;
935 
                        when SERVICE_INTERRUPT8 =>
936 
                                eth_next_state <= CHECK_IF_ACK_WAITING;
937 
 
938 
                        when PRE_TX_TRANSMIT0 =>
939 
                                eth_next_state <= PRE_TX_TRANSMIT1;
940 
                        when PRE_TX_TRANSMIT1 =>
941 
                                if spi_oper_cmplt = '1' then
942 
                                        eth_next_state <= PRE_TX_TRANSMIT2;
943 
                                end if;
944 
                        when PRE_TX_TRANSMIT2 =>
945 
                                eth_next_state <= PRE_TX_TRANSMIT3;
946 
                        when PRE_TX_TRANSMIT3 =>
947 
                                if spi_oper_cmplt = '1' then
948 
                                        eth_next_state <= PRE_TX_TRANSMIT4;
949 
                                end if;
950 
                        when PRE_TX_TRANSMIT4 =>
951 
                                eth_next_state <= PRE_TX_TRANSMIT5;
952 
                        when PRE_TX_TRANSMIT5 =>
953 
                                if spi_oper_cmplt = '1' then
954 
                                        eth_next_state <= HANDLE_TX_TRANSMIT0;
955 
                                end if;
956 
                        when HANDLE_TX_TRANSMIT0 =>
957 
                                eth_next_state <= HANDLE_TX_TRANSMIT1;
958 
                        when HANDLE_TX_TRANSMIT1 =>
959 
                                if spi_oper_cmplt = '1' then
960 
                                        eth_next_state <= HANDLE_TX_TRANSMIT2;
961 
                                end if;
962 
                        when HANDLE_TX_TRANSMIT2 =>
963 
                                eth_next_state <= HANDLE_TX_TRANSMIT3;
964 
                        when HANDLE_TX_TRANSMIT3 =>
965 
                                if spi_oper_cmplt = '1' then
966 
                                        eth_next_state <= HANDLE_TX_TRANSMIT4;
967 
                                end if;
968 
                        when HANDLE_TX_TRANSMIT4 =>
969 
                                eth_next_state <= HANDLE_TX_TRANSMIT5;
970 
                        when HANDLE_TX_TRANSMIT5 =>
971 
                                if spi_oper_cmplt = '1' then
972 
                                        eth_next_state <= HANDLE_TX_TRANSMIT6;
973 
                                end if;
974 
                        when HANDLE_TX_TRANSMIT6 =>
975 
                                eth_next_state <= HANDLE_TX_TRANSMIT7;
976 
                        when HANDLE_TX_TRANSMIT7 =>
977 
                                if tx_packet_length_counter = X"0000" then
978 
                                        eth_next_state <= HANDLE_TX_TRANSMIT_PRE11;
979 
                                else
980 
                                        eth_next_state <= HANDLE_TX_TRANSMIT8;
981 
                                end if;
982 
                        when HANDLE_TX_TRANSMIT8 =>
983 
                                eth_next_state <= HANDLE_TX_TRANSMIT9;
984 
                        when HANDLE_TX_TRANSMIT9 =>
985 
                                eth_next_state <= HANDLE_TX_TRANSMIT10;
986 
                        when HANDLE_TX_TRANSMIT10 =>
987 
                                if spi_wr_cmplt = '1' then
988 
                                        eth_next_state <= HANDLE_TX_TRANSMIT7;
989 
                                end if;
990 
                        when HANDLE_TX_TRANSMIT_PRE11 =>
991 
                                if spi_oper_cmplt = '1' then
992 
                                        eth_next_state <= HANDLE_TX_TRANSMIT11;
993 
                                end if;
994 
                        when HANDLE_TX_TRANSMIT11 =>
995 
                                eth_next_state <= HANDLE_TX_TRANSMIT12;
996 
                        when HANDLE_TX_TRANSMIT12 =>
997 
                                if spi_oper_cmplt = '1' then
998 
                                        eth_next_state <= HANDLE_TX_TRANSMIT13;
999 
                                end if;
1000 
                        when HANDLE_TX_TRANSMIT13 =>
1001 
                                eth_next_state <= HANDLE_TX_TRANSMIT14;
1002 
                        when HANDLE_TX_TRANSMIT14 =>
1003 
                                if spi_oper_cmplt = '1' then
1004 
                                        eth_next_state <= HANDLE_TX_TRANSMIT15;
1005 
                                end if;
1006 
                        when HANDLE_TX_TRANSMIT15 =>
1007 
                                eth_next_state <= HANDLE_TX_TRANSMIT16;
1008 
                        when HANDLE_TX_TRANSMIT16 =>
1009 
                                if spi_oper_cmplt = '1' then
1010 
                                        eth_next_state <= HANDLE_TX_TRANSMIT17;
1011 
                                end if;
1012 
                        when HANDLE_TX_TRANSMIT17 =>
1013 
                                eth_next_state <= HANDLE_TX_TRANSMIT18;
1014 
                        when HANDLE_TX_TRANSMIT18 =>
1015 
                                if spi_oper_cmplt = '1' then
1016 
                                        eth_next_state <= HANDLE_TX_TRANSMIT19;
1017 
                                end if;
1018 
                        when HANDLE_TX_TRANSMIT19 =>
1019 
                                eth_next_state <= HANDLE_TX_TRANSMIT20;
1020 
                        when HANDLE_TX_TRANSMIT20 =>
1021 
                                if spi_oper_cmplt = '1' then
1022 
                                        eth_next_state <= HANDLE_TX_TRANSMIT21;
1023 
                                end if;
1024 
                        when HANDLE_TX_TRANSMIT21 =>
1025 
                                if spi_data_rd(3) = '1' then -- TX has completed
1026 
                                        eth_next_state <= HANDLE_TX_TRANSMIT22;
1027 
                                else
1028 
                                        eth_next_state <= HANDLE_TX_TRANSMIT19;
1029 
                                end if;
1030 
                        when HANDLE_TX_TRANSMIT22 =>
1031 
                                eth_next_state <= IDLE;
1032 
 
1033 
                        when HANDLE_TX_TRANSMIT_PREV0 =>
1034 
                                eth_next_state <= HANDLE_TX_TRANSMIT_PREV1;
1035 
                        when HANDLE_TX_TRANSMIT_PREV1 =>
1036 
                                if spi_oper_cmplt = '1' then
1037 
                                        eth_next_state <= HANDLE_TX_TRANSMIT_PREV2;
1038 
                                end if;
1039 
                        when HANDLE_TX_TRANSMIT_PREV2 =>
1040 
                                eth_next_state <= HANDLE_TX_TRANSMIT_PREV3;
1041 
                        when HANDLE_TX_TRANSMIT_PREV3 =>
1042 
                                if spi_oper_cmplt = '1' then
1043 
                                        eth_next_state <= HANDLE_TX_TRANSMIT_PREV4;
1044 
                                end if;
1045 
                        when HANDLE_TX_TRANSMIT_PREV4 =>
1046 
                                eth_next_state <= HANDLE_TX_TRANSMIT_PREV5;
1047 
                        when HANDLE_TX_TRANSMIT_PREV5 =>
1048 
                                if spi_oper_cmplt = '1' then
1049 
                                        eth_next_state <= HANDLE_TX_TRANSMIT_PREV6;
1050 
                                end if;
1051 
                        when HANDLE_TX_TRANSMIT_PREV6 =>
1052 
                                eth_next_state <= HANDLE_TX_TRANSMIT_PREV7;
1053 
                        when HANDLE_TX_TRANSMIT_PREV7 =>
1054 
                                if spi_oper_cmplt = '1' then
1055 
                                        eth_next_state <= HANDLE_TX_TRANSMIT_PREV8;
1056 
                                end if;
1057 
                        when HANDLE_TX_TRANSMIT_PREV8 =>
1058 
                                eth_next_state <= HANDLE_TX_TRANSMIT_PREV9;
1059 
                        when HANDLE_TX_TRANSMIT_PREV9 =>
1060 
                                if spi_oper_cmplt = '1' then
1061 
                                        eth_next_state <= HANDLE_TX_TRANSMIT_PREV10;
1062 
                                end if;
1063 
                        when HANDLE_TX_TRANSMIT_PREV10 =>
1064 
                                eth_next_state <= HANDLE_TX_TRANSMIT_PREV11;
1065 
                        when HANDLE_TX_TRANSMIT_PREV11 =>
1066 
                                if spi_oper_cmplt = '1' then
1067 
                                        eth_next_state <= HANDLE_TX_TRANSMIT_PREV12;
1068 
                                end if;
1069 
                        when HANDLE_TX_TRANSMIT_PREV12 =>
1070 
                                eth_next_state <= HANDLE_TX_TRANSMIT_PREV13;
1071 
                        when HANDLE_TX_TRANSMIT_PREV13 =>
1072 
                                if spi_oper_cmplt = '1' then
1073 
                                        eth_next_state <= HANDLE_TX_TRANSMIT_PREV14;
1074 
                                end if;
1075 
                        when HANDLE_TX_TRANSMIT_PREV14 =>
1076 
                                eth_next_state <= HANDLE_TX_TRANSMIT_PREV15;
1077 
                        when HANDLE_TX_TRANSMIT_PREV15 =>
1078 
                                if spi_oper_cmplt = '1' then
1079 
                                        eth_next_state <= HANDLE_TX_TRANSMIT_PREV16;
1080 
                                end if;
1081 
                        when HANDLE_TX_TRANSMIT_PREV16 =>
1082 
                                eth_next_state <= WAIT_FOR_TRANSMIT_CMPLT;
1083 
                        when WAIT_FOR_TRANSMIT_CMPLT =>
1084 
                                if tx_timeout_counter = '0'&X"00000" then
1085 
                                        eth_next_state <= PRE_TX_TRANSMIT0;
1086 
                                end if;
1087 
 
1088 
                        when RESEND_ACK_IN_BUFFER =>
1089 
                                eth_next_state <= HANDLE_TX_TRANSMIT15;
1090 
 
1091 
                end case;
1092 
        end process;
1093 
 
1094 
        WR_CONTINUOUS_PROC :process(CLK_IN)
1095 
        begin
1096 
                if rising_edge(CLK_IN) then
1097 
                        if eth_state = HANDLE_TX_TRANSMIT6 then
1098 
                                spi_wr_continuous <= '1';
1099 
                        elsif tx_packet_length_counter = X"0000" then
1100 
                                spi_wr_continuous <= '0';
1101 
                        end if;
1102 
                end if;
1103 
        end process;
1104 
 
1105 
        POLL_INT_PROC :process(CLK_IN)
1106 
        begin
1107 
                if rising_edge(CLK_IN) then
1108 
                        poll_counter <= poll_counter - 1;
1109 
                        if poll_counter = X"0" then
1110 
                                poll_interrupt_reg <= '1';
1111 
                        else
1112 
                                poll_interrupt_reg <= '0';
1113 
                        end if;
1114 
                        if INIT_ENC28J60 = '1' then
1115 
                                init_enc28j60_waiting <= '1';
1116 
                        elsif eth_state = HANDLE_INIT_CMND0 then
1117 
                                init_enc28j60_waiting <= '0';
1118 
                        end if;
1119 
                        if DHCP_CONNECT = '1' then
1120 
                                dhcp_connect_waiting <= '1';
1121 
                        elsif eth_state = TRIGGER_DHCP_DISCOVER then
1122 
                                dhcp_connect_waiting <= '0';
1123 
                        end if;
1124 
                        if eth_state = TRIGGER_TCP_TX0 or tx_packets_no_ack > X"1"
1125 
                                        or wait_for_tcp_window_size_update = '1' then
1126 
                                tcp_data_flush_waiting <= '0';
1127 
                        elsif tcp_wr_data_flush = '1' and tcp_connection_active = '1' then
1128 
                                tcp_data_flush_waiting <= '1';
1129 
                        end if;
1130 
                        if unsigned(tcp_wr_data_count) < X"580" or tcp_connection_active = '0'
1131 
                                        or tx_packets_no_ack > X"1" or wait_for_tcp_window_size_update = '1' then
1132 
                                large_tx_packet_waiting <= '0';
1133 
                        else
1134 
                                large_tx_packet_waiting <= '1';
1135 
                        end if;
1136 
                        if trigger_send_prev_packet = '1' then
1137 
                                send_prev_packet_waiting <= '1';
1138 
                        elsif eth_state = HANDLE_TX_TRANSMIT_PREV0 then
1139 
                                send_prev_packet_waiting <= '0';
1140 
                        end if;
1141 
                end if;
1142 
        end process;
1143 
 
1144 
        TX_PACKET_LENGTH_PROC :process(CLK_IN)
1145 
        begin
1146 
                if rising_edge(CLK_IN) then
1147 
                        if eth_state = HANDLE_TX_TRANSMIT5 then
1148 
                                tx_packet_length_counter <= tx_packet_length;
1149 
                        elsif eth_state = HANDLE_TX_TRANSMIT9 then
1150 
                                tx_packet_length_counter <= tx_packet_length_counter - 1;
1151 
                        end if;
1152 
                        if eth_state = HANDLE_TX_TRANSMIT5 then
1153 
                                tx_packet_ram_rd_addr <= "00000000000";
1154 
                        elsif eth_state = HANDLE_TX_TRANSMIT9 then
1155 
                                tx_packet_ram_rd_addr <= tx_packet_ram_rd_addr + 1;
1156 
                        end if;
1157 
                end if;
1158 
        end process;
1159 
 
1160 
   INIT_ADDR_PROC: process(CLK_IN)
1161 
   begin
1162 
      if rising_edge(CLK_IN) then
1163 
                        if eth_state = HANDLE_INIT_CMND0 then
1164 
                                init_cmnd_addr <= unsigned(C_init_cmnds_start_addr);
1165 
                        elsif eth_state = HANDLE_INIT_CMND3 then
1166 
                                init_cmnd_addr <= init_cmnd_addr + 1;
1167 
                        end if;
1168 
      end if;
1169 
   end process;
1170 
 
1171 
   SLOW_CS_PROC: process(CLK_IN)
1172 
   begin
1173 
      if rising_edge(CLK_IN) then
1174 
                        if eth_state = HANDLE_INIT_CMND0 then
1175 
                                slow_cs_en <= '1';
1176 
                        elsif eth_state = IDLE then
1177 
                                slow_cs_en <= '0';
1178 
                        end if;
1179 
      end if;
1180 
   end process;
1181 
 
1182 
   FRAME_ADDR_PROC: process(CLK_IN)
1183 
   begin
1184 
      if rising_edge(CLK_IN) then
1185 
                        if eth_state = HANDLE_INIT_CMND1 then
1186 
                                frame_addr <= "000" & slv(init_cmnd_addr);
1187 
                        end if;
1188 
      end if;
1189 
   end process;
1190 
 
1191 
        SETTINGS_PROC: process(CLK_IN)
1192 
   begin
1193 
      if rising_edge(CLK_IN) then
1194 
                        if eth_state = HANDLE_INIT_CMND0 then
1195 
                                network_interface_enabled <= '0';
1196 
                        elsif eth_state = HANDLE_INIT_CMND6 then
1197 
                                network_interface_enabled <= '1'; -- TODO add disable code
1198 
                        end if;
1199 
                end if;
1200 
        end process;
1201 
 
1202 
        SPI_WR_PROC: process(CLK_IN)
1203 
   begin
1204 
      if rising_edge(CLK_IN) then
1205 
                        if eth_state = HANDLE_INIT_CMND3 then
1206 
                                spi_we <= '1';
1207 
                        elsif eth_state = SERVICE_INTERRUPT0 then
1208 
                                spi_we <= '1';
1209 
                        elsif eth_state = SERVICE_INTERRUPT6 then
1210 
                                spi_we <= '1';
1211 
                        elsif eth_state = HANDLE_TX_INTERRUPT0 then
1212 
                                spi_we <= '1';
1213 
                        elsif eth_state = HANDLE_RX_INTERRUPT5 then
1214 
                                spi_we <= '1';
1215 
                        elsif eth_state = HANDLE_RX_INTERRUPT7 then
1216 
                                spi_we <= '1';
1217 
                        elsif eth_state = HANDLE_RX_INTERRUPT9 then
1218 
                                spi_we <= '1';
1219 
                        elsif eth_state = HANDLE_RX_INTERRUPT11 then
1220 
                                spi_we <= '1';
1221 
                        elsif eth_state = HANDLE_RX_INTERRUPT13 then
1222 
                                spi_we <= '1';
1223 
                        elsif eth_state = HANDLE_RX_INTERRUPT15 then
1224 
                                spi_we <= '1';
1225 
                        elsif eth_state = PRE_TX_TRANSMIT0 then
1226 
                                spi_we <= '1';
1227 
                        elsif eth_state = PRE_TX_TRANSMIT2 then
1228 
                                spi_we <= '1';
1229 
                        elsif eth_state = PRE_TX_TRANSMIT4 then
1230 
                                spi_we <= '1';
1231 
                        elsif eth_state = HANDLE_TX_TRANSMIT0 then
1232 
                                spi_we <= '1';
1233 
                        elsif eth_state = HANDLE_TX_TRANSMIT2 then
1234 
                                spi_we <= '1';
1235 
                        elsif eth_state = HANDLE_TX_TRANSMIT4 then
1236 
                                spi_we <= '1';
1237 
                        elsif eth_state = HANDLE_TX_TRANSMIT6 then
1238 
                                spi_we <= '1';
1239 
                        elsif eth_state = HANDLE_TX_TRANSMIT11 then
1240 
                                spi_we <= '1';
1241 
                        elsif eth_state = HANDLE_TX_TRANSMIT13 then
1242 
                                spi_we <= '1';
1243 
                        elsif eth_state = HANDLE_TX_TRANSMIT15 then
1244 
                                spi_we <= '1';
1245 
                        elsif eth_state = HANDLE_TX_TRANSMIT17 then
1246 
                                spi_we <= '1';
1247 
                        elsif eth_state = HANDLE_TX_TRANSMIT_PREV0 then
1248 
                                spi_we <= '1';
1249 
                        elsif eth_state = HANDLE_TX_TRANSMIT_PREV2 then
1250 
                                spi_we <= '1';
1251 
                        elsif eth_state = HANDLE_TX_TRANSMIT_PREV4 then
1252 
                                spi_we <= '1';
1253 
                        elsif eth_state = HANDLE_TX_TRANSMIT_PREV6 then
1254 
                                spi_we <= '1';
1255 
                        elsif eth_state = HANDLE_TX_TRANSMIT_PREV8 then
1256 
                                spi_we <= '1';
1257 
                        elsif eth_state = HANDLE_TX_TRANSMIT_PREV10 then
1258 
                                spi_we <= '1';
1259 
                        elsif eth_state = HANDLE_TX_TRANSMIT_PREV12 then
1260 
                                spi_we <= '1';
1261 
                        elsif eth_state = HANDLE_TX_TRANSMIT_PREV14 then
1262 
                                spi_we <= '1';
1263 
                        else
1264 
                                spi_we <= '0';
1265 
                        end if;
1266 
      end if;
1267 
   end process;
1268 
 
1269 
        SPI_ADDR_PROC: process(CLK_IN)
1270 
   begin
1271 
      if rising_edge(CLK_IN) then
1272 
                        if eth_state = HANDLE_INIT_CMND3 then
1273 
                                spi_wr_addr <= frame_data(15 downto 8);
1274 
                        elsif eth_state = SERVICE_INTERRUPT0 then
1275 
                                spi_wr_addr <= X"BB";
1276 
                        elsif eth_state = HANDLE_TX_INTERRUPT0 then
1277 
                                spi_wr_addr <= X"BC";
1278 
                        elsif eth_state = HANDLE_RX_INTERRUPT5 then
1279 
                                spi_wr_addr <= X"BF";
1280 
                        elsif eth_state = HANDLE_RX_INTERRUPT7 then
1281 
                                spi_wr_addr <= X"4C";
1282 
                        elsif eth_state = HANDLE_RX_INTERRUPT9 then
1283 
                                spi_wr_addr <= X"4D";
1284 
                        elsif eth_state = HANDLE_RX_INTERRUPT11 then
1285 
                                spi_wr_addr <= X"40";
1286 
                        elsif eth_state = HANDLE_RX_INTERRUPT13 then
1287 
                                spi_wr_addr <= X"41";
1288 
                        elsif eth_state = HANDLE_RX_INTERRUPT15 then
1289 
                                spi_wr_addr <= X"9E";
1290 
                        elsif eth_state = SERVICE_INTERRUPT6 then
1291 
                                spi_wr_addr <= X"9B";
1292 
                        elsif eth_state = PRE_TX_TRANSMIT0 then
1293 
                                spi_wr_addr <= X"BF";
1294 
                        elsif eth_state = PRE_TX_TRANSMIT2 then
1295 
                                spi_wr_addr <= X"42";
1296 
                        elsif eth_state = PRE_TX_TRANSMIT4 then
1297 
                                spi_wr_addr <= X"43";
1298 
                        elsif eth_state = HANDLE_TX_TRANSMIT0 then
1299 
                                spi_wr_addr <= X"44";
1300 
                        elsif eth_state = HANDLE_TX_TRANSMIT2 then
1301 
                                spi_wr_addr <= X"45";
1302 
                        elsif eth_state = HANDLE_TX_TRANSMIT4 then
1303 
                                spi_wr_addr <= X"7A";
1304 
                        elsif eth_state = HANDLE_TX_TRANSMIT6 then
1305 
                                spi_wr_addr <= X"7A";
1306 
                        elsif eth_state = HANDLE_TX_TRANSMIT11 then
1307 
                                spi_wr_addr <= X"46";
1308 
                        elsif eth_state = HANDLE_TX_TRANSMIT13 then
1309 
                                spi_wr_addr <= X"47";
1310 
                        elsif eth_state = HANDLE_TX_TRANSMIT15 then
1311 
                                spi_wr_addr <= X"BC";
1312 
                        elsif eth_state = HANDLE_TX_TRANSMIT17 then
1313 
                                spi_wr_addr <= X"9F";
1314 
                        elsif eth_state = HANDLE_TX_TRANSMIT_PREV0 then
1315 
                                spi_wr_addr <= X"BF";
1316 
                        elsif eth_state = HANDLE_TX_TRANSMIT_PREV2 then
1317 
                                spi_wr_addr <= X"42";
1318 
                        elsif eth_state = HANDLE_TX_TRANSMIT_PREV4 then
1319 
                                spi_wr_addr <= X"43";
1320 
                        elsif eth_state = HANDLE_TX_TRANSMIT_PREV6 then
1321 
                                spi_wr_addr <= X"44";
1322 
                        elsif eth_state = HANDLE_TX_TRANSMIT_PREV8 then
1323 
                                spi_wr_addr <= X"45";
1324 
                        elsif eth_state = HANDLE_TX_TRANSMIT_PREV10 then
1325 
                                spi_wr_addr <= X"46";
1326 
                        elsif eth_state = HANDLE_TX_TRANSMIT_PREV12 then
1327 
                                spi_wr_addr <= X"47";
1328 
                        elsif eth_state = HANDLE_TX_TRANSMIT_PREV14 then
1329 
                                spi_wr_addr <= X"9F";
1330 
                        end if;
1331 
      end if;
1332 
   end process;
1333 
 
1334 
        SPI_DATA_PROC: process(CLK_IN)
1335 
   begin
1336 
      if rising_edge(CLK_IN) then
1337 
                        if eth_state = HANDLE_INIT_CMND3 then
1338 
                                spi_wr_data <= frame_data(7 downto 0);
1339 
                        elsif eth_state = SERVICE_INTERRUPT0 then
1340 
                                spi_wr_data <= X"80";
1341 
                        elsif eth_state = HANDLE_TX_INTERRUPT0 then
1342 
                                spi_wr_data <= X"08";
1343 
                        elsif eth_state = HANDLE_RX_INTERRUPT5 then
1344 
                                spi_wr_data <= X"03";
1345 
                        elsif eth_state = HANDLE_RX_INTERRUPT7 then
1346 
                                spi_wr_data <= next_packet_pointer(7 downto 0);
1347 
                        elsif eth_state = HANDLE_RX_INTERRUPT9 then
1348 
                                spi_wr_data <= next_packet_pointer(15 downto 8);
1349 
                        elsif eth_state = HANDLE_RX_INTERRUPT11 then
1350 
                                spi_wr_data <= next_packet_pointer(7 downto 0);
1351 
                        elsif eth_state = HANDLE_RX_INTERRUPT13 then
1352 
                                spi_wr_data <= next_packet_pointer(15 downto 8);
1353 
                        elsif eth_state = HANDLE_RX_INTERRUPT15 then
1354 
                                spi_wr_data <= X"40";
1355 
                        elsif eth_state = SERVICE_INTERRUPT6 then
1356 
                                spi_wr_data <= X"80";
1357 
                        elsif eth_state = PRE_TX_TRANSMIT0 then
1358 
                                spi_wr_data <= X"03";
1359 
                        elsif eth_state = PRE_TX_TRANSMIT2 then
1360 
                                spi_wr_data <= slv(tx_base_addr(7 downto 0));
1361 
                        elsif eth_state = PRE_TX_TRANSMIT4 then
1362 
                                spi_wr_data <= slv(tx_base_addr(15 downto 8));
1363 
                        elsif eth_state = HANDLE_TX_TRANSMIT0 then
1364 
                                spi_wr_data <= slv(tx_base_addr(7 downto 0));
1365 
                        elsif eth_state = HANDLE_TX_TRANSMIT2 then
1366 
                                spi_wr_data <= slv(tx_base_addr(15 downto 8));
1367 
                        elsif eth_state = HANDLE_TX_TRANSMIT4 then
1368 
                                spi_wr_data <= X"00";
1369 
                        elsif eth_state = HANDLE_TX_TRANSMIT6 then
1370 
                                spi_wr_data <= tx_packet_rd_data;
1371 
                        elsif eth_state = HANDLE_TX_TRANSMIT10 then
1372 
                                spi_wr_data <= tx_packet_rd_data;
1373 
                        elsif eth_state = HANDLE_TX_TRANSMIT11 then
1374 
                                spi_wr_data <= slv(tx_packet_end_pointer(7 downto 0));
1375 
                        elsif eth_state = HANDLE_TX_TRANSMIT13 then
1376 
                                spi_wr_data <= slv(tx_packet_end_pointer(15 downto 8));
1377 
                        elsif eth_state = HANDLE_TX_TRANSMIT15 then
1378 
                                spi_wr_data <= X"08";
1379 
                        elsif eth_state = HANDLE_TX_TRANSMIT17 then
1380 
                                spi_wr_data <= X"08";
1381 
                        elsif eth_state = HANDLE_TX_TRANSMIT_PREV0 then
1382 
                                spi_wr_data <= X"03";
1383 
                        elsif eth_state = HANDLE_TX_TRANSMIT_PREV2 then
1384 
                                spi_wr_data <= slv(tx_base_addr(7 downto 0));
1385 
                        elsif eth_state = HANDLE_TX_TRANSMIT_PREV4 then
1386 
                                spi_wr_data <= slv(tx_base_addr(15 downto 8));
1387 
                        elsif eth_state = HANDLE_TX_TRANSMIT_PREV6 then
1388 
                                spi_wr_data <= slv(tx_base_addr(7 downto 0));
1389 
                        elsif eth_state = HANDLE_TX_TRANSMIT_PREV8 then
1390 
                                spi_wr_data <= slv(tx_base_addr(15 downto 8));
1391 
                        elsif eth_state = HANDLE_TX_TRANSMIT_PREV10 then
1392 
                                spi_wr_data <= slv(prev_tx_packet_end_pointer(7 downto 0));
1393 
                        elsif eth_state = HANDLE_TX_TRANSMIT_PREV12 then
1394 
                                spi_wr_data <= slv(prev_tx_packet_end_pointer(15 downto 8));
1395 
                        elsif eth_state = HANDLE_TX_TRANSMIT_PREV14 then
1396 
                                spi_wr_data <= X"08";
1397 
                        end if;
1398 
      end if;
1399 
   end process;
1400 
 
1401 
        COMMAND_CMPLT_PROC: process(CLK_IN)
1402 
   begin
1403 
      if rising_edge(CLK_IN) then
1404 
                        if eth_state /= IDLE and eth_next_state = IDLE then
1405 
                                command_cmplt <= '1';
1406 
                        elsif eth_state /= IDLE and eth_next_state /= IDLE then
1407 
                                command_cmplt <= '0';
1408 
                        end if;
1409 
      end if;
1410 
   end process;
1411 
 
1412 
        SPI_RD_ADDR_PROC: process(CLK_IN)
1413 
   begin
1414 
      if rising_edge(CLK_IN) then
1415 
                        if eth_state = SERVICE_INTERRUPT2 then
1416 
                                spi_rd_addr <= X"1C";
1417 
                        elsif eth_state = HANDLE_RX_INTERRUPT0 then
1418 
                                spi_rd_addr <= X"3A";
1419 
                        elsif eth_state = HANDLE_RX_INTERRUPT2 then
1420 
                                spi_rd_addr <= X"3A";
1421 
                        elsif eth_state = COPY_RX_PACKET_TO_BUF1 then
1422 
                                spi_rd_addr <= X"3A";
1423 
                        elsif eth_state = HANDLE_TX_TRANSMIT19 then
1424 
                                spi_rd_addr <= X"1C";
1425 
                        end if;
1426 
      end if;
1427 
   end process;
1428 
 
1429 
        SPI_RD_FLAG_PROC: process(CLK_IN)
1430 
   begin
1431 
      if rising_edge(CLK_IN) then
1432 
                        if eth_state = SERVICE_INTERRUPT2 then
1433 
                                spi_rd <= '1';
1434 
                        elsif eth_state = HANDLE_RX_INTERRUPT0 then
1435 
                                spi_rd <= '1';
1436 
                        elsif eth_state = HANDLE_RX_INTERRUPT2 then
1437 
                                spi_rd <= '1';
1438 
                        elsif eth_state = COPY_RX_PACKET_TO_BUF1 then
1439 
                                spi_rd <= '1';
1440 
                        elsif eth_state = HANDLE_TX_TRANSMIT19 then
1441 
                                spi_rd <= '1';
1442 
                        else
1443 
                                spi_rd <= '0';
1444 
                        end if;
1445 
      end if;
1446 
   end process;
1447 
 
1448 
        RD_CONTINUOUS_PROC: process(CLK_IN)
1449 
   begin
1450 
      if rising_edge(CLK_IN) then
1451 
                        if eth_state = COPY_RX_PACKET_TO_BUF1 then
1452 
                                spi_rd_continuous <= '1';
1453 
                        elsif eth_state = COPY_RX_PACKET_TO_BUF5 then
1454 
                                spi_rd_continuous <= '0';
1455 
                        end if;
1456 
      end if;
1457 
   end process;
1458 
 
1459 
        ENC_VERSION_PROC: process(CLK_IN)
1460 
   begin
1461 
      if rising_edge(CLK_IN) then
1462 
                        if eth_state = SERVICE_INTERRUPT4 then
1463 
                                eir_register <= spi_data_rd;
1464 
                        end if;
1465 
                        if eth_state = HANDLE_RX_INTERRUPT2 then
1466 
                                next_packet_pointer(7 downto 0) <= spi_data_rd;
1467 
                        end if;
1468 
                        if eth_state = HANDLE_RX_INTERRUPT4 then
1469 
                                next_packet_pointer(15 downto 8) <= spi_data_rd;
1470 
                        end if;
1471 
      end if;
1472 
   end process;
1473 
 
1474 
------------------------- RX PACKET --------------------------------
1475 
 
1476 
        handle_rx_packet <= '1' when eth_state = COPY_RX_PACKET_TO_BUF6 else '0';
1477 
        trigger_ack <= '1' when eth_state = TRIGGER_ACK_PACKET else '0';
1478 
        handle_tx_packet <= '1' when eth_state = TRIGGER_TCP_TX1 else '0';
1479 
 
1480 
        process(CLK_IN)
1481 
   begin
1482 
      if rising_edge(CLK_IN) then
1483 
                        if eth_state = HANDLE_RX_INTERRUPT0 then
1484 
                                debug_rx_flag <= '1';
1485 
                        elsif eth_state = HANDLE_RX_INTERRUPT17 then
1486 
                                debug_rx_flag <= '0';
1487 
                        end if;
1488 
                end if;
1489 
        end process;
1490 
 
1491 
        RX_PACKET_WR_ADDR: process(CLK_IN)
1492 
   begin
1493 
      if rising_edge(CLK_IN) then
1494 
                        if eth_state = COPY_RX_PACKET_TO_BUF0 then
1495 
                                rx_packet_ram_we_addr_buf <= "00000000000";
1496 
                        elsif eth_state = COPY_RX_PACKET_TO_BUF3 then
1497 
                                rx_packet_ram_we_addr_buf <= rx_packet_ram_we_addr_buf + 1;
1498 
                        end if;
1499 
                        if eth_state = HANDLE_RX_INTERRUPT5 then
1500 
                                previous_packet_pointer <= unsigned(next_packet_pointer);
1501 
                        elsif eth_state = COPY_RX_PACKET_TO_BUF3 then
1502 
                                if previous_packet_pointer = C_rx_pointer_max then
1503 
                                        previous_packet_pointer <= C_rx_pointer_min;
1504 
                                else
1505 
                                        previous_packet_pointer <= previous_packet_pointer + 1;
1506 
                                end if;
1507 
                        end if;
1508 
                end if;
1509 
        end process;
1510 
 
1511 
        rx_packet_ram_we <= '1' when eth_state = COPY_RX_PACKET_TO_BUF3 else '0';
1512 
        rx_packet_ram_we_addr <= rx_packet_ram_we_addr_buf when doing_tx_packet_config = '0' else rx_packet_rd2_addr;
1513 
 
1514 
        RX_PACKET_RAM : TDP_RAM
1515 
                Generic Map (   G_DATA_A_SIZE   => spi_data_rd'length,
1516 
                                                        G_ADDR_A_SIZE   => rx_packet_ram_we_addr'length,
1517 
                                                        G_RELATION              => 0, --log2(SIZE_A/SIZE_B)
1518 
                                                        G_INIT_ZERO             => true,
1519 
                                                        G_INIT_FILE             => "")
1520 
                Port Map ( CLK_A_IN     => CLK_IN,
1521 
                                 WE_A_IN                => rx_packet_ram_we,
1522 
                                 ADDR_A_IN              => slv(rx_packet_ram_we_addr),
1523 
                                 DATA_A_IN              => spi_data_rd,
1524 
                                 DATA_A_OUT             => rx_packet_rd_data2,
1525 
                                 CLK_B_IN               => CLK_IN,
1526 
                                 WE_B_IN                => '0',
1527 
                                 ADDR_B_IN              => slv(rx_packet_ram_rd_addr),
1528 
                                 DATA_B_IN              => X"00",
1529 
                                 DATA_B_OUT     => rx_packet_rd_data);
1530 
 
1531 
        PH_SYNC_PROC: process(CLK_IN)
1532 
   begin
1533 
      if rising_edge(CLK_IN) then
1534 
                        packet_handler_state <= packet_handler_next_state;
1535 
      end if;
1536 
   end process;
1537 
 
1538 
        rx_packet_handled <= '1' when packet_handler_state = COMPLETE else '0';
1539 
 
1540 
        send_arp_reply <= '1' when packet_handler_state = TRIGGER_ARP_REPLY else '0';
1541 
        send_icmp_reply <= '1' when packet_handler_state = TRIGGER_ICMP_PACKET_REPLY else '0';
1542 
        send_dhcp_request <= '1' when packet_handler_state = TRIGGER_DHCP_REQUEST else '0';
1543 
        send_tcp_ack_packet <= '1' when packet_handler_state = TRIGGER_TCP_ACK3 else '0';
1544 
        send_tcp_tx_packet <= '1' when packet_handler_state = TRIGGER_TCP_PSH_ACK2 else '0';
1545 
 
1546 
        send_arp_request <= '1' when eth_state = TRIGGER_ARP_REQUEST else '0';
1547 
        send_dhcp_discover <= '1' when eth_state = TRIGGER_DHCP_DISCOVER else '0';
1548 
        cancel_dhcp_connect <= '1' when eth_state = TRIGGER_CANCEL_DHCP_CONNECT else '0';
1549 
        close_tcp_connection <= '1' when eth_state = TRIGGER_CLOSE_TCP_CONNECTION else '0';
1550 
        cancel_tcp_connection <= '1' when eth_state = TRIGGER_CANCEL_TCP_CONNECTION else '0';
1551 
 
1552 
        PH_NEXT_STATE_DECODE: process (packet_handler_state, handle_rx_packet, rx_packet_status_vector(23), rx_tcp_flags,
1553 
                                                                                                rx_packet_type, arp_target_ip_addr, rx_tcp_option, tcp_option_addr, total_packet_length,
1554 
                                                                                                        rx_tcp_option_length, arp_opcode, expecting_arp_reply, ip_addr, tx_packet_config_cmplt,
1555 
                                                                                                                ip_packet_version, ip_packet_destination_ip, dhcp_enable, dhcp_addr_locked, ip_packet_protocol,
1556 
                                                                                                                        ip_packet_length, udp_source_port, udp_dest_port, dhcp_transaction_id, transaction_id_rd,
1557 
                                                                                                                                dhcp_magic_cookie, dhcp_option, dhcp_option_length, dhcp_option_addr, expecting_syn_ack,
1558 
                                                                                                                                        dhcp_message_type, expecting_dhcp_offer, expecting_dhcp_ack, rx_tcp_source_port,
1559 
                                                                                                                                                listen_port, rx_tcp_dest_port, client_port, ping_enable, rx_tcp_header_length, tcp_sequence_number_p1,
1560 
                                                                                                                                                        rx_tcp_ack_number, tcp_sequence_number, tcp_acknowledge_number, rx_tcp_seq_number, rx_packet_ram_rd_addr,
1561 
                                                                                                                                                                tx_packet_state)
1562 
   begin
1563 
      packet_handler_next_state <= packet_handler_state;  --default is to stay in current state
1564 
      case (packet_handler_state) is
1565 
         when IDLE =>
1566 
                                if tx_packet_state = IDLE then          -- only configure new packet if currently not transmitting a packet
1567 
                                        if handle_rx_packet = '1' then
1568 
                                                packet_handler_next_state <= PARSE_SOURCE_MAC0;
1569 
                                        elsif trigger_ack = '1' then
1570 
                                                packet_handler_next_state <= TRIGGER_TCP_ACK0;
1571 
                                        elsif handle_tx_packet = '1' then
1572 
                                                packet_handler_next_state <= CHECK_IF_DATA_TO_SEND;
1573 
                                        end if;
1574 
                                end if;
1575 
                        when PARSE_SOURCE_MAC0 =>
1576 
                                packet_handler_next_state <= PARSE_SOURCE_MAC1;
1577 
                        when PARSE_SOURCE_MAC1 =>
1578 
                                packet_handler_next_state <= PARSE_SOURCE_MAC2;
1579 
                        when PARSE_SOURCE_MAC2 =>
1580 
                                packet_handler_next_state <= PARSE_SOURCE_MAC3;
1581 
                        when PARSE_SOURCE_MAC3 =>
1582 
                                packet_handler_next_state <= PARSE_SOURCE_MAC4;
1583 
                        when PARSE_SOURCE_MAC4 =>
1584 
                                packet_handler_next_state <= PARSE_SOURCE_MAC5;
1585 
                        when PARSE_SOURCE_MAC5 =>
1586 
                                packet_handler_next_state <= PARSE_SOURCE_MAC6;
1587 
                        when PARSE_SOURCE_MAC6 =>
1588 
                                packet_handler_next_state <= PARSE_SOURCE_MAC7;
1589 
                        when PARSE_SOURCE_MAC7 =>
1590 
                                packet_handler_next_state <= PARSE_PACKET_TYPE0;
1591 
                        when PARSE_PACKET_TYPE0 =>
1592 
                                packet_handler_next_state <= PARSE_PACKET_TYPE1;
1593 
                        when PARSE_PACKET_TYPE1 =>
1594 
                                packet_handler_next_state <= PARSE_PACKET_TYPE2;
1595 
                        when PARSE_PACKET_TYPE2 =>
1596 
                                packet_handler_next_state <= PARSE_PACKET_TYPE3;
1597 
                        when PARSE_PACKET_TYPE3 =>
1598 
                                packet_handler_next_state <= PARSE_PACKET_TYPE4;
1599 
                        when PARSE_PACKET_TYPE4 =>
1600 
                                if rx_packet_type = C_ARP_Packet_Type then
1601 
                                        packet_handler_next_state <= HANDLE_ARP_PACKET0;
1602 
                                elsif rx_packet_type = C_IP_Packet_Type then
1603 
                                        packet_handler_next_state <= HANDLE_IP_PACKET0;
1604 
                                else
1605 
                                        packet_handler_next_state <= COMPLETE;
1606 
                                end if;
1607 
 
1608 
                        when HANDLE_ARP_PACKET0 =>
1609 
                                packet_handler_next_state <= HANDLE_ARP_PACKET1;
1610 
                        when HANDLE_ARP_PACKET1 =>
1611 
                                packet_handler_next_state <= HANDLE_ARP_PACKET2;
1612 
                        when HANDLE_ARP_PACKET2 =>
1613 
                                packet_handler_next_state <= HANDLE_ARP_PACKET3;
1614 
                        when HANDLE_ARP_PACKET3 =>
1615 
                                if arp_opcode = C_ARP_Request then
1616 
                                        packet_handler_next_state <= HANDLE_ARP_REQUEST0;
1617 
                                elsif arp_opcode = C_ARP_Reply then
1618 
                                        packet_handler_next_state <= HANDLE_ARP_REPLY0;
1619 
                                else
1620 
                                        packet_handler_next_state <= COMPLETE;
1621 
                                end if;
1622 
 
1623 
                        when HANDLE_ARP_REPLY0 =>
1624 
                                if expecting_arp_reply = '1' then
1625 
                                        packet_handler_next_state <= HANDLE_ARP_REPLY1;
1626 
                                else
1627 
                                        packet_handler_next_state <= COMPLETE;
1628 
                                end if;
1629 
                        when HANDLE_ARP_REPLY1 =>
1630 
                                packet_handler_next_state <= HANDLE_ARP_REPLY2;
1631 
                        when HANDLE_ARP_REPLY2 =>
1632 
                                packet_handler_next_state <= HANDLE_ARP_REPLY3;
1633 
                        when HANDLE_ARP_REPLY3 =>
1634 
                                packet_handler_next_state <= HANDLE_ARP_REPLY4;
1635 
                        when HANDLE_ARP_REPLY4 =>
1636 
                                packet_handler_next_state <= HANDLE_ARP_REPLY5;
1637 
                        when HANDLE_ARP_REPLY5 =>
1638 
                                packet_handler_next_state <= HANDLE_ARP_REPLY6;
1639 
                        when HANDLE_ARP_REPLY6 =>
1640 
                                packet_handler_next_state <= HANDLE_ARP_REPLY7;
1641 
                        when HANDLE_ARP_REPLY7 =>
1642 
                                packet_handler_next_state <= COMPLETE;
1643 
 
1644 
                        when HANDLE_ARP_REQUEST0 =>
1645 
                                packet_handler_next_state <= HANDLE_ARP_REQUEST1;
1646 
                        when HANDLE_ARP_REQUEST1 =>
1647 
                                packet_handler_next_state <= HANDLE_ARP_REQUEST2;
1648 
                        when HANDLE_ARP_REQUEST2 =>
1649 
                                packet_handler_next_state <= HANDLE_ARP_REQUEST3;
1650 
                        when HANDLE_ARP_REQUEST3 =>
1651 
                                packet_handler_next_state <= HANDLE_ARP_REQUEST4;
1652 
                        when HANDLE_ARP_REQUEST4 =>
1653 
                                packet_handler_next_state <= HANDLE_ARP_REQUEST5;
1654 
                        when HANDLE_ARP_REQUEST5 =>
1655 
                                packet_handler_next_state <= HANDLE_ARP_REQUEST6;
1656 
                        when HANDLE_ARP_REQUEST6 =>
1657 
                                if arp_target_ip_addr = ip_addr then
1658 
                                        packet_handler_next_state <= HANDLE_ARP_REQUEST7;
1659 
                                else
1660 
                                        packet_handler_next_state <= COMPLETE;
1661 
                                end if;
1662 
                        when HANDLE_ARP_REQUEST7 =>
1663 
                                packet_handler_next_state <= HANDLE_ARP_REQUEST8;
1664 
                        when HANDLE_ARP_REQUEST8 =>
1665 
                                packet_handler_next_state <= HANDLE_ARP_REQUEST9;
1666 
                        when HANDLE_ARP_REQUEST9 =>
1667 
                                packet_handler_next_state <= HANDLE_ARP_REQUEST10;
1668 
                        when HANDLE_ARP_REQUEST10 =>
1669 
                                packet_handler_next_state <= HANDLE_ARP_REQUEST11;
1670 
                        when HANDLE_ARP_REQUEST11 =>
1671 
                                packet_handler_next_state <= HANDLE_ARP_REQUEST12;
1672 
                        when HANDLE_ARP_REQUEST12 =>
1673 
                                packet_handler_next_state <= HANDLE_ARP_REQUEST13;
1674 
                        when HANDLE_ARP_REQUEST13 =>
1675 
                                packet_handler_next_state <= TRIGGER_ARP_REPLY;
1676 
 
1677 
                        when TRIGGER_ARP_REPLY =>
1678 
                                if tx_packet_config_cmplt = '1' then
1679 
                                        packet_handler_next_state <= COMPLETE;
1680 
                                end if;
1681 
 
1682 
                        when HANDLE_IP_PACKET0 =>
1683 
                                packet_handler_next_state <= HANDLE_IP_PACKET1;
1684 
                        when HANDLE_IP_PACKET1 =>
1685 
                                packet_handler_next_state <= HANDLE_IP_PACKET2;
1686 
                        when HANDLE_IP_PACKET2 =>
1687 
                                packet_handler_next_state <= HANDLE_IP_PACKET3;
1688 
                        when HANDLE_IP_PACKET3 =>
1689 
                                packet_handler_next_state <= HANDLE_IP_PACKET4;
1690 
                        when HANDLE_IP_PACKET4 =>
1691 
                                packet_handler_next_state <= HANDLE_IP_PACKET5;
1692 
                        when HANDLE_IP_PACKET5 =>
1693 
                                packet_handler_next_state <= HANDLE_IP_PACKET6;
1694 
                        when HANDLE_IP_PACKET6 =>
1695 
                                packet_handler_next_state <= HANDLE_IP_PACKET7;
1696 
                        when HANDLE_IP_PACKET7 =>
1697 
                                packet_handler_next_state <= HANDLE_IP_PACKET8;
1698 
                        when HANDLE_IP_PACKET8 =>
1699 
                                packet_handler_next_state <= HANDLE_IP_PACKET9;
1700 
                        when HANDLE_IP_PACKET9 =>
1701 
                                packet_handler_next_state <= HANDLE_IP_PACKET10;
1702 
                        when HANDLE_IP_PACKET10 =>
1703 
                                if ip_packet_version = C_IPV4_Protocol_Number then
1704 
                                        packet_handler_next_state <= HANDLE_IP_PACKET11;
1705 
                                else
1706 
                                        packet_handler_next_state <= COMPLETE;
1707 
                                end if;
1708 
                        when HANDLE_IP_PACKET11 =>
1709 
                                if ip_packet_destination_ip = ip_addr then
1710 
                                        packet_handler_next_state <= HANDLE_IP_PACKET12;
1711 
                                elsif dhcp_enable = '1' and dhcp_addr_locked = '0' then
1712 
                                        packet_handler_next_state <= HANDLE_IP_PACKET12;
1713 
                                else
1714 
                                        packet_handler_next_state <= COMPLETE;
1715 
                                end if;
1716 
                        when HANDLE_IP_PACKET12 =>
1717 
                                if ip_packet_protocol = C_ICMP_Protocol_Number then
1718 
                                        packet_handler_next_state <= PRE_ICMP_PACKET_REPLY;
1719 
                                elsif ip_packet_protocol = C_UDP_Protocol_Number then
1720 
                                        packet_handler_next_state <= PARSE_UDP_PACKET0;
1721 
                                elsif ip_packet_protocol = C_TCP_Protocol_Number then
1722 
                                        packet_handler_next_state <= PARSE_TCP_PACKET0;
1723 
                                else
1724 
                                        packet_handler_next_state <= COMPLETE;
1725 
                                end if;
1726 
 
1727 
                        when PRE_ICMP_PACKET_REPLY =>
1728 
                                if ip_packet_length = C_ICMP_Ping_Length and ping_enable = '1' then
1729 
                                        packet_handler_next_state <= TRIGGER_ICMP_PACKET_REPLY;
1730 
                                else
1731 
                                        packet_handler_next_state <= COMPLETE;
1732 
                                end if;
1733 
                        when TRIGGER_ICMP_PACKET_REPLY =>
1734 
                                if tx_packet_config_cmplt = '1' then
1735 
                                        packet_handler_next_state <= COMPLETE;
1736 
                                end if;
1737 
 
1738 
                        when PARSE_UDP_PACKET0 =>
1739 
                                packet_handler_next_state <= PARSE_UDP_PACKET1;
1740 
                        when PARSE_UDP_PACKET1 =>
1741 
                                packet_handler_next_state <= PARSE_UDP_PACKET2;
1742 
                        when PARSE_UDP_PACKET2 =>
1743 
                                packet_handler_next_state <= PARSE_UDP_PACKET3;
1744 
                        when PARSE_UDP_PACKET3 =>
1745 
                                packet_handler_next_state <= PARSE_UDP_PACKET4;
1746 
                        when PARSE_UDP_PACKET4 =>
1747 
                                packet_handler_next_state <= PARSE_UDP_PACKET5;
1748 
                        when PARSE_UDP_PACKET5 =>
1749 
                                packet_handler_next_state <= PARSE_UDP_PACKET_TYPE0;
1750 
                        when PARSE_UDP_PACKET_TYPE0 =>
1751 
                                if udp_source_port = C_DHCP_Source_Port then
1752 
                                        packet_handler_next_state <= PARSE_UDP_PACKET_TYPE1;
1753 
                                else
1754 
                                        packet_handler_next_state <= COMPLETE;
1755 
                                end if;
1756 
                        when PARSE_UDP_PACKET_TYPE1 =>
1757 
                                if udp_dest_port = C_DHCP_Dest_Port then
1758 
                                        packet_handler_next_state <= PARSE_DHCP_PACKET0;
1759 
                                else
1760 
                                        packet_handler_next_state <= COMPLETE;
1761 
                                end if;
1762 
 
1763 
                        when PARSE_DHCP_PACKET0 =>
1764 
                                packet_handler_next_state <= PARSE_DHCP_PACKET1;
1765 
                        when PARSE_DHCP_PACKET1 =>
1766 
                                packet_handler_next_state <= PARSE_DHCP_PACKET2;
1767 
                        when PARSE_DHCP_PACKET2 =>
1768 
                                packet_handler_next_state <= PARSE_DHCP_PACKET3;
1769 
                        when PARSE_DHCP_PACKET3 =>
1770 
                                packet_handler_next_state <= PARSE_DHCP_PACKET4;
1771 
                        when PARSE_DHCP_PACKET4 =>
1772 
                                packet_handler_next_state <= PARSE_DHCP_PACKET5;
1773 
                        when PARSE_DHCP_PACKET5 =>
1774 
                                packet_handler_next_state <= PARSE_DHCP_PACKET6;
1775 
                        when PARSE_DHCP_PACKET6 =>
1776 
                                if dhcp_transaction_id = transaction_id_rd then
1777 
                                        packet_handler_next_state <= PARSE_DHCP_PACKET7;
1778 
                                else
1779 
                                        packet_handler_next_state <= COMPLETE;
1780 
                                end if;
1781 
                        when PARSE_DHCP_PACKET7 =>
1782 
                                packet_handler_next_state <= PARSE_DHCP_PACKET8;
1783 
                        when PARSE_DHCP_PACKET8 =>
1784 
                                packet_handler_next_state <= PARSE_DHCP_PACKET9;
1785 
                        when PARSE_DHCP_PACKET9 =>
1786 
                                packet_handler_next_state <= PARSE_DHCP_PACKET10;
1787 
                        when PARSE_DHCP_PACKET10 =>
1788 
                                packet_handler_next_state <= PARSE_DHCP_PACKET11;
1789 
                        when PARSE_DHCP_PACKET11 =>
1790 
                                packet_handler_next_state <= PARSE_DHCP_PACKET12;
1791 
                        when PARSE_DHCP_PACKET12 =>
1792 
                                packet_handler_next_state <= PARSE_DHCP_PACKET13;
1793 
                        when PARSE_DHCP_PACKET13 =>
1794 
                                packet_handler_next_state <= PARSE_DHCP_PACKET14;
1795 
                        when PARSE_DHCP_PACKET14 =>
1796 
                                packet_handler_next_state <= PARSE_DHCP_PACKET15;
1797 
                        when PARSE_DHCP_PACKET15 =>
1798 
                                packet_handler_next_state <= PARSE_DHCP_PACKET16;
1799 
                        when PARSE_DHCP_PACKET16 =>
1800 
                                packet_handler_next_state <= PARSE_DHCP_PACKET17;
1801 
                        when PARSE_DHCP_PACKET17 =>
1802 
                                packet_handler_next_state <= PARSE_DHCP_PACKET18;
1803 
                        when PARSE_DHCP_PACKET18 =>
1804 
                                if C_dhcp_magic_cookie = dhcp_magic_cookie then
1805 
                                        packet_handler_next_state <= PARSE_DHCP_PACKET19;
1806 
                                else
1807 
                                        packet_handler_next_state <= COMPLETE;
1808 
                                end if;
1809 
 
1810 
                        when PARSE_DHCP_PACKET19 =>
1811 
                                packet_handler_next_state <= PARSE_DHCP_PACKET20;
1812 
                        when PARSE_DHCP_PACKET20 =>
1813 
                                packet_handler_next_state <= PARSE_DHCP_PACKET21;
1814 
                        when PARSE_DHCP_PACKET21 =>
1815 
                                packet_handler_next_state <= PARSE_DHCP_PACKET22;
1816 
                        when PARSE_DHCP_PACKET22 =>
1817 
                                packet_handler_next_state <= PARSE_DHCP_PACKET23;
1818 
                        when PARSE_DHCP_PACKET23 =>
1819 
                                if dhcp_option = X"35" and dhcp_option_length = X"01" then
1820 
                                        packet_handler_next_state <= PARSE_DHCP_PACKET24;
1821 
                                elsif dhcp_option = X"FF" then
1822 
                                        packet_handler_next_state <= COMPLETE;
1823 
                                elsif RESIZE(dhcp_option_addr, 16) > total_packet_length then
1824 
                                        packet_handler_next_state <= COMPLETE;
1825 
                                else
1826 
                                        packet_handler_next_state <= PARSE_DHCP_PACKET19;
1827 
                                end if;
1828 
                        when PARSE_DHCP_PACKET24 =>
1829 
                                if dhcp_message_type = X"02" then -- dhcp offer
1830 
                                        packet_handler_next_state <= CHECK_OFFER_EXPECTED;
1831 
                                elsif dhcp_message_type = X"04" then -- dhcp decline
1832 
                                        packet_handler_next_state <= COMPLETE;
1833 
                                elsif dhcp_message_type = X"05" then -- dhcp acknowledge
1834 
                                        packet_handler_next_state <= HANDLE_DHCP_ACK0;
1835 
                                elsif dhcp_message_type = X"06" then -- dhcp negative acknowledge
1836 
                                        packet_handler_next_state <= COMPLETE;
1837 
                                elsif dhcp_message_type = X"07" then -- dhcp release
1838 
                                        packet_handler_next_state <= COMPLETE;
1839 
                                else
1840 
                                        packet_handler_next_state <= COMPLETE;
1841 
                                end if;
1842 
 
1843 
                        when CHECK_OFFER_EXPECTED =>
1844 
                                if expecting_dhcp_offer = '1' then
1845 
                                        packet_handler_next_state <= TRIGGER_DHCP_REQUEST;
1846 
                                else
1847 
                                        packet_handler_next_state <= COMPLETE;
1848 
                                end if;
1849 
                        when TRIGGER_DHCP_REQUEST =>
1850 
                                if tx_packet_config_cmplt = '1' then
1851 
                                        packet_handler_next_state <= COMPLETE;
1852 
                                end if;
1853 
 
1854 
                        when HANDLE_DHCP_ACK0 =>
1855 
                                if expecting_dhcp_ack = '1' then
1856 
                                        packet_handler_next_state <= HANDLE_DHCP_ACK1;
1857 
                                else
1858 
                                        packet_handler_next_state <= COMPLETE;
1859 
                                end if;
1860 
                        when HANDLE_DHCP_ACK1 =>
1861 
                                packet_handler_next_state <= HANDLE_DHCP_ACK2;
1862 
                        when HANDLE_DHCP_ACK2 =>
1863 
                                packet_handler_next_state <= HANDLE_DHCP_ACK3;
1864 
                        when HANDLE_DHCP_ACK3 =>
1865 
                                packet_handler_next_state <= HANDLE_DHCP_ACK4;
1866 
                        when HANDLE_DHCP_ACK4 =>
1867 
                                packet_handler_next_state <= HANDLE_DHCP_ACK5;
1868 
                        when HANDLE_DHCP_ACK5 =>
1869 
                                packet_handler_next_state <= HANDLE_DHCP_ACK6;
1870 
                        when HANDLE_DHCP_ACK6 =>
1871 
                                packet_handler_next_state <= HANDLE_DHCP_ACK7;
1872 
                        when HANDLE_DHCP_ACK7 =>
1873 
                                packet_handler_next_state <= HANDLE_DHCP_ACK8;
1874 
                        when HANDLE_DHCP_ACK8 =>
1875 
                                packet_handler_next_state <= COMPLETE;
1876 
 
1877 
                        when PARSE_TCP_PACKET0 =>
1878 
                                packet_handler_next_state <= PARSE_TCP_PACKET1;
1879 
                        when PARSE_TCP_PACKET1 =>
1880 
                                packet_handler_next_state <= PARSE_TCP_PACKET2;
1881 
                        when PARSE_TCP_PACKET2 =>
1882 
                                packet_handler_next_state <= PARSE_TCP_PACKET3;
1883 
                        when PARSE_TCP_PACKET3 =>
1884 
                                packet_handler_next_state <= PARSE_TCP_PACKET4;
1885 
                        when PARSE_TCP_PACKET4 =>
1886 
                                packet_handler_next_state <= PARSE_TCP_PACKET5;
1887 
                        when PARSE_TCP_PACKET5 =>
1888 
                                if rx_tcp_source_port = client_port then
1889 
                                        packet_handler_next_state <= PARSE_TCP_PACKET6;
1890 
                                else
1891 
                                        packet_handler_next_state <= COMPLETE;
1892 
                                end if;
1893 
                        when PARSE_TCP_PACKET6 =>
1894 
                                if rx_tcp_dest_port = listen_port then
1895 
                                        packet_handler_next_state <= PARSE_TCP_PACKET7;
1896 
                                else
1897 
                                        packet_handler_next_state <= COMPLETE;
1898 
                                end if;
1899 
                        when PARSE_TCP_PACKET7 =>
1900 
                                packet_handler_next_state <= PARSE_TCP_PACKET8;
1901 
                        when PARSE_TCP_PACKET8 =>
1902 
                                packet_handler_next_state <= PARSE_TCP_PACKET9;
1903 
                        when PARSE_TCP_PACKET9 =>
1904 
                                packet_handler_next_state <= PARSE_TCP_PACKET10;
1905 
                        when PARSE_TCP_PACKET10 =>
1906 
                                packet_handler_next_state <= PARSE_TCP_PACKET11;
1907 
                        when PARSE_TCP_PACKET11 =>
1908 
                                packet_handler_next_state <= PARSE_TCP_PACKET12;
1909 
                        when PARSE_TCP_PACKET12 =>
1910 
                                packet_handler_next_state <= PARSE_TCP_PACKET13;
1911 
                        when PARSE_TCP_PACKET13 =>
1912 
                                packet_handler_next_state <= PARSE_TCP_PACKET14;
1913 
                        when PARSE_TCP_PACKET14 =>
1914 
                                packet_handler_next_state <= PARSE_TCP_PACKET15;
1915 
                        when PARSE_TCP_PACKET15 =>
1916 
                                packet_handler_next_state <= PARSE_TCP_PACKET16;
1917 
                        when PARSE_TCP_PACKET16 =>
1918 
                                packet_handler_next_state <= PARSE_TCP_PACKET17;
1919 
                        when PARSE_TCP_PACKET17 =>
1920 
                                packet_handler_next_state <= PARSE_TCP_PACKET18;
1921 
                        when PARSE_TCP_PACKET18 =>
1922 
                                packet_handler_next_state <= PARSE_TCP_PACKET19;
1923 
                        when PARSE_TCP_PACKET19 =>
1924 
                                if rx_tcp_flags(4 downto 1) = X"1" and tcp_connection_active = '0' then -- SYN PACKET (READ OPTIONS)
1925 
                                        packet_handler_next_state <= PARSE_TCP_PACKET20;
1926 
                                else
1927 
                                        packet_handler_next_state <= PARSE_TCP_PACKET25;
1928 
                                end if;
1929 
                        when PARSE_TCP_PACKET20 =>
1930 
                                packet_handler_next_state <= PARSE_TCP_PACKET21;
1931 
                        when PARSE_TCP_PACKET21 =>
1932 
                                packet_handler_next_state <= PARSE_TCP_PACKET22;
1933 
                        when PARSE_TCP_PACKET22 =>
1934 
                                packet_handler_next_state <= PARSE_TCP_PACKET23;
1935 
                        when PARSE_TCP_PACKET23 =>
1936 
                                packet_handler_next_state <= PARSE_TCP_PACKET24;
1937 
                        when PARSE_TCP_PACKET24 =>
1938 
                                if rx_tcp_option = X"03" then
1939 
                                        packet_handler_next_state <= PARSE_TCP_PACKET25;
1940 
                                elsif rx_tcp_option = X"01" then
1941 
                                        packet_handler_next_state <= PARSE_TCP_PACKET26;
1942 
                                elsif RESIZE(tcp_option_addr, 16) > total_packet_length then
1943 
                                        packet_handler_next_state <= COMPLETE;
1944 
                                else
1945 
                                        packet_handler_next_state <= PARSE_TCP_PACKET27;
1946 
                                end if;
1947 
                        when PARSE_TCP_PACKET25 =>
1948 
                                if rx_tcp_flags(4 downto 1) = X"1" and tcp_connection_active = '0' then
1949 
                                        packet_handler_next_state <= CHECK_TCP_SYN_PACKET0;
1950 
                                elsif rx_tcp_flags(4 downto 1) = X"C" or rx_tcp_flags(4 downto 1) = X"8" then
1951 
                                        packet_handler_next_state <= CHECK_TCP_PSH_ACK_PACKET0;
1952 
                                else
1953 
                                        packet_handler_next_state <= COMPLETE;
1954 
                                end if;
1955 
                        when PARSE_TCP_PACKET26 =>
1956 
                                packet_handler_next_state <= PARSE_TCP_PACKET20;
1957 
                        when PARSE_TCP_PACKET27 =>
1958 
                                if rx_tcp_option_length = X"00" then
1959 
                                        packet_handler_next_state <= COMPLETE;
1960 
                                else
1961 
                                        packet_handler_next_state <= PARSE_TCP_PACKET20;
1962 
                                end if;
1963 
                        when CHECK_TCP_SYN_PACKET0 =>
1964 
                                packet_handler_next_state <= CHECK_TCP_SYN_PACKET1;
1965 
                        when CHECK_TCP_SYN_PACKET1 =>
1966 
                                packet_handler_next_state <= CHECK_TCP_SYN_PACKET2;
1967 
                        when CHECK_TCP_SYN_PACKET2 =>
1968 
                                packet_handler_next_state <= CHECK_TCP_SYN_PACKET3;
1969 
                        when CHECK_TCP_SYN_PACKET3 =>
1970 
                                packet_handler_next_state <= CHECK_TCP_SYN_PACKET4;
1971 
                        when CHECK_TCP_SYN_PACKET4 =>
1972 
                                packet_handler_next_state <= CHECK_TCP_SYN_PACKET5;
1973 
                        when CHECK_TCP_SYN_PACKET5 =>
1974 
                                packet_handler_next_state <= TRIGGER_TCP_ACK0;
1975 
 
1976 
                        when CHECK_TCP_PSH_ACK_PACKET0 =>
1977 
                                if tcp_sequence_number = unsigned(rx_tcp_ack_number) then
1978 
                                        packet_handler_next_state <= CHECK_TCP_PSH_ACK_PACKET1;
1979 
                                else
1980 
                                        packet_handler_next_state <= COMPLETE;
1981 
                                end if;
1982 
                        when CHECK_TCP_PSH_ACK_PACKET1 =>
1983 
                                if tcp_acknowledge_number = unsigned(rx_tcp_seq_number) then
1984 
                                        packet_handler_next_state <= CHECK_TCP_PSH_ACK_PACKET2;
1985 
                                else
1986 
                                        packet_handler_next_state <= RESEND_ACK;        -- ACK failed to reach target, resend
1987 
                                end if;
1988 
                        when CHECK_TCP_PSH_ACK_PACKET2 =>
1989 
                                if rx_data_length /= X"0000" then
1990 
                                        packet_handler_next_state <= CHECK_TCP_PSH_ACK_PACKET3;
1991 
                                else
1992 
                                        packet_handler_next_state <= COMPLETE; -- This was just an ACK
1993 
                                end if;
1994 
                        when CHECK_TCP_PSH_ACK_PACKET3 =>
1995 
                                packet_handler_next_state <= READ_TCP_RX_DATA;
1996 
 
1997 
                        when READ_TCP_RX_DATA =>
1998 
                                if RESIZE(rx_packet_ram_rd_addr, 16) > total_packet_length then
1999 
                                        packet_handler_next_state <= COMPLETE;
2000 
                                end if;
2001 
 
2002 
                        when TRIGGER_TCP_ACK0 =>
2003 
                                packet_handler_next_state <= TRIGGER_TCP_ACK1;
2004 
                        when TRIGGER_TCP_ACK1 =>
2005 
                                if window_size > X"136" then
2006 
                                        packet_handler_next_state <= TRIGGER_TCP_ACK2;
2007 
                                end if;
2008 
                        when TRIGGER_TCP_ACK2 =>
2009 
                                packet_handler_next_state <= TRIGGER_TCP_ACK3;
2010 
                        when TRIGGER_TCP_ACK3 =>
2011 
                                if tx_packet_state = INIT_TCP_PACKET_METADATA then
2012 
                                        packet_handler_next_state <= COMPLETE;
2013 
                                end if;
2014 
 
2015 
                        when RESEND_ACK =>
2016 
                                packet_handler_next_state <= COMPLETE;
2017 
 
2018 
                        when CHECK_IF_DATA_TO_SEND =>
2019 
                                if tcp_wr_data_count /= X"000" then
2020 
                                        packet_handler_next_state <= TRIGGER_TCP_PSH_ACK0;
2021 
                                else
2022 
                                        packet_handler_next_state <= COMPLETE;
2023 
                                end if;
2024 
                        when TRIGGER_TCP_PSH_ACK0 =>
2025 
                                packet_handler_next_state <= TRIGGER_TCP_PSH_ACK1;
2026 
                        when TRIGGER_TCP_PSH_ACK1 =>
2027 
                                if rx_tcp_window_size_shifted(31 downto 12) = X"00000" then
2028 
                                        packet_handler_next_state <= CHECK_TCP_WINDOW_SIZE;
2029 
                                else
2030 
                                        packet_handler_next_state <= TRIGGER_TCP_PSH_ACK2;
2031 
                                end if;
2032 
                        when CHECK_TCP_WINDOW_SIZE =>
2033 
                                if tx_bytes_to_send > unsigned(rx_tcp_window_size_shifted(11 downto 0)) then -- server is not ready to receive data yet
2034 
                                        packet_handler_next_state <= RX_TCP_WINDOW_TOO_SMALL;
2035 
                                else
2036 
                                        packet_handler_next_state <= TRIGGER_TCP_PSH_ACK2;
2037 
                                end if;
2038 
                        when TRIGGER_TCP_PSH_ACK2 =>
2039 
                                if tx_packet_state = SET_CHECKSUM_LENGTH_TX_PACKET_LENGTH0 then -- wait until packet is formed before incrementing sequence number
2040 
                                        packet_handler_next_state <= TRIGGER_TCP_PSH_ACK3;
2041 
                                end if;
2042 
                        when TRIGGER_TCP_PSH_ACK3 =>
2043 
                                packet_handler_next_state <= COMPLETE;
2044 
 
2045 
                        when RX_TCP_WINDOW_TOO_SMALL =>
2046 
                                packet_handler_next_state <= IDLE;
2047 
                        when COMPLETE =>
2048 
                                packet_handler_next_state <= IDLE;
2049 
 
2050 
                end case;
2051 
        end process;
2052 
 
2053 
        ACK_TIMER_PROC: process(CLK_IN)
2054 
        begin
2055 
                if rising_edge(CLK_IN) then
2056 
                        if packet_handler_state = CHECK_TCP_PSH_ACK_PACKET3 then
2057 
                                ack_countdown <= C_250us;
2058 
                        elsif ack_countdown /= X"0000" then
2059 
                                ack_countdown <= ack_countdown - 1;
2060 
                        end if;
2061 
                        if ack_countdown = X"0001" then
2062 
                                ack_required <= '1';
2063 
                        elsif trigger_fin_ack = '1' then
2064 
                                ack_required <= '1';
2065 
                        elsif packet_handler_state = TRIGGER_TCP_ACK0 then
2066 
                                ack_required <= '0';
2067 
                        end if;
2068 
                        if packet_handler_state = RESEND_ACK then
2069 
                                resend_ack_packet <= '1';
2070 
                        elsif eth_state = RESEND_ACK_IN_BUFFER then
2071 
                                resend_ack_packet <= '0';
2072 
                        end if;
2073 
                        if packet_handler_state = RX_TCP_WINDOW_TOO_SMALL then
2074 
                                wait_for_tcp_window_size_update <= '1';
2075 
                        elsif packet_handler_state = PARSE_TCP_PACKET25 then
2076 
                                wait_for_tcp_window_size_update <= '0';
2077 
                        end if;
2078 
                end if;
2079 
        end process;
2080 
 
2081 
        RX_PACKET_RD_ADDR: process(CLK_IN)
2082 
        begin
2083 
                if rising_edge(CLK_IN) then
2084 
                        if packet_handler_state = PARSE_SOURCE_MAC0 then
2085 
                                rx_packet_ram_rd_addr <= "000"&X"0A";
2086 
                        elsif packet_handler_state = PARSE_PACKET_TYPE0 then
2087 
                                rx_packet_ram_rd_addr <= "000"&X"10";
2088 
                        elsif packet_handler_state = HANDLE_ARP_REQUEST0 then
2089 
                                rx_packet_ram_rd_addr <= "000"&X"2A";
2090 
                        elsif packet_handler_state = HANDLE_ARP_REQUEST7 then
2091 
                                rx_packet_ram_rd_addr <= "000"&X"20";
2092 
                        elsif packet_handler_state = HANDLE_IP_PACKET0 then
2093 
                                rx_packet_ram_rd_addr <= "000"&X"12";
2094 
                        elsif packet_handler_state = HANDLE_IP_PACKET1 then
2095 
                                rx_packet_ram_rd_addr <= "000"&X"1B";
2096 
                        elsif packet_handler_state = HANDLE_IP_PACKET2 then
2097 
                                rx_packet_ram_rd_addr <= "000"&X"22";
2098 
                        elsif packet_handler_state = HANDLE_IP_PACKET6 then
2099 
                                rx_packet_ram_rd_addr <= "000"&X"14";
2100 
                        elsif packet_handler_state = PARSE_UDP_PACKET0 then
2101 
                                rx_packet_ram_rd_addr <= "000"&X"26";
2102 
                        elsif packet_handler_state = PARSE_DHCP_PACKET0 then
2103 
                                rx_packet_ram_rd_addr <= "000"&X"32";
2104 
                        elsif packet_handler_state = PARSE_DHCP_PACKET4 then
2105 
                                rx_packet_ram_rd_addr <= "000"&X"3E";
2106 
                        elsif packet_handler_state = PARSE_DHCP_PACKET12 then
2107 
                                rx_packet_ram_rd_addr <= "001"&X"1A";
2108 
                        elsif packet_handler_state = PARSE_DHCP_PACKET19 then
2109 
                                rx_packet_ram_rd_addr <= dhcp_option_addr;
2110 
                        elsif packet_handler_state = HANDLE_ARP_PACKET0 then
2111 
                                rx_packet_ram_rd_addr <= "000"&X"19";
2112 
                        elsif packet_handler_state = HANDLE_ARP_REPLY0 then
2113 
                                rx_packet_ram_rd_addr <= "000"&X"1A";
2114 
                        elsif packet_handler_state = PARSE_TCP_PACKET0 then
2115 
                                rx_packet_ram_rd_addr <= next_protocol_start_addr;
2116 
                        elsif packet_handler_state = PARSE_TCP_PACKET20 then
2117 
                                rx_packet_ram_rd_addr <= tcp_option_addr;
2118 
                        elsif packet_handler_state = CHECK_TCP_PSH_ACK_PACKET1 then
2119 
                                rx_packet_ram_rd_addr <= rx_data_start_addr;
2120 
                        elsif packet_handler_state = HANDLE_DHCP_ACK1 then
2121 
                                rx_packet_ram_rd_addr <= "000"&X"0A";
2122 
                        else
2123 
                                rx_packet_ram_rd_addr <= rx_packet_ram_rd_addr + 1;
2124 
                        end if;
2125 
                        if packet_handler_state = HANDLE_ARP_PACKET2 then
2126 
                                arp_opcode <= rx_packet_rd_data;
2127 
                        end if;
2128 
                        if packet_handler_state = HANDLE_ARP_REQUEST9 then
2129 
                                arp_source_ip_addr(31 downto 24) <= rx_packet_rd_data;
2130 
                        elsif packet_handler_state = HANDLE_ARP_REQUEST10 then
2131 
                                arp_source_ip_addr(23 downto 16) <= rx_packet_rd_data;
2132 
                        elsif packet_handler_state = HANDLE_ARP_REQUEST11 then
2133 
                                arp_source_ip_addr(15 downto 8) <= rx_packet_rd_data;
2134 
                        elsif packet_handler_state = HANDLE_ARP_REQUEST12 then
2135 
                                arp_source_ip_addr(7 downto 0) <= rx_packet_rd_data;
2136 
                        end if;
2137 
                        if packet_handler_state = HANDLE_ARP_REQUEST2 then
2138 
                                arp_target_ip_addr(31 downto 24) <= rx_packet_rd_data;
2139 
                        elsif packet_handler_state = HANDLE_ARP_REQUEST3 then
2140 
                                arp_target_ip_addr(23 downto 16) <= rx_packet_rd_data;
2141 
                        elsif packet_handler_state = HANDLE_ARP_REQUEST4 then
2142 
                                arp_target_ip_addr(15 downto 8) <= rx_packet_rd_data;
2143 
                        elsif packet_handler_state = HANDLE_ARP_REQUEST5 then
2144 
                                arp_target_ip_addr(7 downto 0) <= rx_packet_rd_data;
2145 
                        end if;
2146 
                        if packet_handler_state = PARSE_SOURCE_MAC2 then
2147 
                                rx_packet_source_mac(47 downto 40) <= rx_packet_rd_data;
2148 
                        elsif packet_handler_state = PARSE_SOURCE_MAC3 then
2149 
                                rx_packet_source_mac(39 downto 32) <= rx_packet_rd_data;
2150 
                        elsif packet_handler_state = PARSE_SOURCE_MAC4 then
2151 
                                rx_packet_source_mac(31 downto 24) <= rx_packet_rd_data;
2152 
                        elsif packet_handler_state = PARSE_SOURCE_MAC5 then
2153 
                                rx_packet_source_mac(23 downto 16) <= rx_packet_rd_data;
2154 
                        elsif packet_handler_state = PARSE_SOURCE_MAC6 then
2155 
                                rx_packet_source_mac(15 downto 8) <= rx_packet_rd_data;
2156 
                        elsif packet_handler_state = PARSE_SOURCE_MAC7 then
2157 
                                rx_packet_source_mac(7 downto 0) <= rx_packet_rd_data;
2158 
                        end if;
2159 
                        if packet_handler_state = PARSE_PACKET_TYPE2 then
2160 
                                rx_packet_type(15 downto 8) <= rx_packet_rd_data;
2161 
                        elsif packet_handler_state = PARSE_PACKET_TYPE3 then
2162 
                                rx_packet_type(7 downto 0) <= rx_packet_rd_data;
2163 
                        end if;
2164 
                        if packet_handler_state = HANDLE_IP_PACKET2 then
2165 
                                ip_packet_version <= rx_packet_rd_data(7 downto 4);
2166 
                        end if;
2167 
                        if packet_handler_state = HANDLE_IP_PACKET3 then
2168 
                                ip_packet_protocol <= rx_packet_rd_data;
2169 
                        end if;
2170 
                        if packet_handler_state = HANDLE_IP_PACKET2 then
2171 
                                ip_packet_header_length(3 downto 0) <= rx_packet_rd_data(3 downto 0);
2172 
                                ip_packet_header_length(7 downto 4) <= X"0";
2173 
                        elsif packet_handler_state = HANDLE_IP_PACKET3 then
2174 
                                ip_packet_header_length <= ip_packet_header_length(5 downto 0) & "00";
2175 
                        end if;
2176 
                        if packet_handler_state = HANDLE_IP_PACKET4 then
2177 
                                next_protocol_start_addr <= RESIZE(unsigned(ip_packet_header_length), 11) + "00000010010"; -- src/dest mac + protocol + status reg (4 bytes)
2178 
                        end if;
2179 
                        if packet_handler_state = HANDLE_IP_PACKET4 then
2180 
                                ip_packet_destination_ip(31 downto 24) <= rx_packet_rd_data;
2181 
                        elsif packet_handler_state = HANDLE_IP_PACKET5 then
2182 
                                ip_packet_destination_ip(23 downto 16) <= rx_packet_rd_data;
2183 
                        elsif packet_handler_state = HANDLE_IP_PACKET6 then
2184 
                                ip_packet_destination_ip(15 downto 8) <= rx_packet_rd_data;
2185 
                        elsif packet_handler_state = HANDLE_IP_PACKET7 then
2186 
                                ip_packet_destination_ip(7 downto 0) <= rx_packet_rd_data;
2187 
                        end if;
2188 
                        if packet_handler_state = HANDLE_IP_PACKET8 then
2189 
                                ip_packet_length(15 downto 8) <= rx_packet_rd_data;
2190 
                        elsif packet_handler_state = HANDLE_IP_PACKET9 then
2191 
                                ip_packet_length(7 downto 0) <= rx_packet_rd_data;
2192 
                        end if;
2193 
                        if packet_handler_state = HANDLE_IP_PACKET10 then -- TODO Rename ip_packet_length ?
2194 
                                total_packet_length <= unsigned(ip_packet_length) + X"0012"; -- src/dest mac + protocol + status reg (4 bytes)
2195 
                        end if;
2196 
                        if packet_handler_state = PARSE_UDP_PACKET2 then
2197 
                                udp_source_port(15 downto 8) <= rx_packet_rd_data;
2198 
                        elsif packet_handler_state = PARSE_UDP_PACKET3 then
2199 
                                udp_source_port(7 downto 0) <= rx_packet_rd_data;
2200 
                        end if;
2201 
                        if packet_handler_state = PARSE_UDP_PACKET4 then
2202 
                                udp_dest_port(15 downto 8) <= rx_packet_rd_data;
2203 
                        elsif packet_handler_state = PARSE_UDP_PACKET5 then
2204 
                                udp_dest_port(7 downto 0) <= rx_packet_rd_data;
2205 
                        end if;
2206 
                        if packet_handler_state = PARSE_DHCP_PACKET2 then
2207 
                                transaction_id_rd(31 downto 24) <= rx_packet_rd_data;
2208 
                        elsif packet_handler_state = PARSE_DHCP_PACKET3 then
2209 
                                transaction_id_rd(23 downto 16) <= rx_packet_rd_data;
2210 
                        elsif packet_handler_state = PARSE_DHCP_PACKET4 then
2211 
                                transaction_id_rd(15 downto 8) <= rx_packet_rd_data;
2212 
                        elsif packet_handler_state = PARSE_DHCP_PACKET5 then
2213 
                                transaction_id_rd(7 downto 0) <= rx_packet_rd_data;
2214 
                        end if;
2215 
                        if packet_handler_state = PARSE_DHCP_PACKET6 then
2216 
                                dhcp_your_ip_addr(31 downto 24) <= rx_packet_rd_data;
2217 
                        elsif packet_handler_state = PARSE_DHCP_PACKET7 then
2218 
                                dhcp_your_ip_addr(23 downto 16) <= rx_packet_rd_data;
2219 
                        elsif packet_handler_state = PARSE_DHCP_PACKET8 then
2220 
                                dhcp_your_ip_addr(15 downto 8) <= rx_packet_rd_data;
2221 
                        elsif packet_handler_state = PARSE_DHCP_PACKET9 then
2222 
                                dhcp_your_ip_addr(7 downto 0) <= rx_packet_rd_data;
2223 
                        end if;
2224 
                        if packet_handler_state = PARSE_DHCP_PACKET10 then
2225 
                                dhcp_server_ip_addr(31 downto 24) <= rx_packet_rd_data;
2226 
                        elsif packet_handler_state = PARSE_DHCP_PACKET11 then
2227 
                                dhcp_server_ip_addr(23 downto 16) <= rx_packet_rd_data;
2228 
                        elsif packet_handler_state = PARSE_DHCP_PACKET12 then
2229 
                                dhcp_server_ip_addr(15 downto 8) <= rx_packet_rd_data;
2230 
                        elsif packet_handler_state = PARSE_DHCP_PACKET13 then
2231 
                                dhcp_server_ip_addr(7 downto 0) <= rx_packet_rd_data;
2232 
                        end if;
2233 
                        if packet_handler_state = PARSE_DHCP_PACKET14 then
2234 
                                dhcp_magic_cookie(31 downto 24) <= rx_packet_rd_data;
2235 
                        elsif packet_handler_state = PARSE_DHCP_PACKET15 then
2236 
                                dhcp_magic_cookie(23 downto 16) <= rx_packet_rd_data;
2237 
                        elsif packet_handler_state = PARSE_DHCP_PACKET16 then
2238 
                                dhcp_magic_cookie(15 downto 8) <= rx_packet_rd_data;
2239 
                        elsif packet_handler_state = PARSE_DHCP_PACKET17 then
2240 
                                dhcp_magic_cookie(7 downto 0) <= rx_packet_rd_data;
2241 
                        end if;
2242 
                        if packet_handler_state = PARSE_DHCP_PACKET21 then
2243 
                                dhcp_option <= rx_packet_rd_data;
2244 
                        end if;
2245 
                        if packet_handler_state = PARSE_DHCP_PACKET22 then
2246 
                                dhcp_option_length <= rx_packet_rd_data;
2247 
                        end if;
2248 
                        if packet_handler_state = PARSE_DHCP_PACKET18 then
2249 
                                dhcp_option_addr <= "001"&X"1E";
2250 
                        elsif packet_handler_state = PARSE_DHCP_PACKET23 then
2251 
                                dhcp_option_addr <= dhcp_option_addr + RESIZE(unsigned(dhcp_option_length), 11);
2252 
                        end if;
2253 
                        if packet_handler_state = PARSE_DHCP_PACKET23 then
2254 
                                dhcp_message_type <= rx_packet_rd_data;
2255 
                        end if;
2256 
                        if (packet_handler_state = CHECK_TCP_SYN_PACKET0) then
2257 
                                client_mac_addr(47 downto 40) <= rx_packet_source_mac(47 downto 40);
2258 
                        elsif (packet_handler_state = CHECK_TCP_SYN_PACKET1) then
2259 
                                client_mac_addr(39 downto 32) <= rx_packet_source_mac(39 downto 32);
2260 
                        elsif (packet_handler_state = CHECK_TCP_SYN_PACKET2) then
2261 
                                client_mac_addr(31 downto 24) <= rx_packet_source_mac(31 downto 24);
2262 
                        elsif (packet_handler_state = CHECK_TCP_SYN_PACKET3) then
2263 
                                client_mac_addr(23 downto 16) <= rx_packet_source_mac(23 downto 16);
2264 
                        elsif (packet_handler_state = CHECK_TCP_SYN_PACKET4) then
2265 
                                client_mac_addr(15 downto 8) <= rx_packet_source_mac(15 downto 8);
2266 
                        elsif (packet_handler_state = CHECK_TCP_SYN_PACKET5) then
2267 
                                client_mac_addr(7 downto 0) <= rx_packet_source_mac(7 downto 0);
2268 
                        end if;
2269 
                        if packet_handler_state = PARSE_TCP_PACKET2 then
2270 
                                rx_tcp_source_port(15 downto 8) <= rx_packet_rd_data;
2271 
                        elsif packet_handler_state = PARSE_TCP_PACKET3 then
2272 
                                rx_tcp_source_port(7 downto 0) <= rx_packet_rd_data;
2273 
                        end if;
2274 
                        if packet_handler_state = PARSE_TCP_PACKET4 then
2275 
                                rx_tcp_dest_port(15 downto 8) <= rx_packet_rd_data;
2276 
                        elsif packet_handler_state = PARSE_TCP_PACKET5 then
2277 
                                rx_tcp_dest_port(7 downto 0) <= rx_packet_rd_data;
2278 
                        end if;
2279 
                        if packet_handler_state = PARSE_TCP_PACKET6 then
2280 
                                rx_tcp_seq_number(31 downto 24) <= rx_packet_rd_data;
2281 
                        elsif packet_handler_state = PARSE_TCP_PACKET7 then
2282 
                                rx_tcp_seq_number(23 downto 16) <= rx_packet_rd_data;
2283 
                        elsif packet_handler_state = PARSE_TCP_PACKET8 then
2284 
                                rx_tcp_seq_number(15 downto 8) <= rx_packet_rd_data;
2285 
                        elsif packet_handler_state = PARSE_TCP_PACKET9 then
2286 
                                rx_tcp_seq_number(7 downto 0) <= rx_packet_rd_data;
2287 
                        end if;
2288 
                        if packet_handler_state = PARSE_TCP_PACKET10 then
2289 
                                rx_tcp_ack_number(31 downto 24) <= rx_packet_rd_data;
2290 
                        elsif packet_handler_state = PARSE_TCP_PACKET11 then
2291 
                                rx_tcp_ack_number(23 downto 16) <= rx_packet_rd_data;
2292 
                        elsif packet_handler_state = PARSE_TCP_PACKET12 then
2293 
                                rx_tcp_ack_number(15 downto 8) <= rx_packet_rd_data;
2294 
                        elsif packet_handler_state = PARSE_TCP_PACKET13 then
2295 
                                rx_tcp_ack_number(7 downto 0) <= rx_packet_rd_data;
2296 
                        end if;
2297 
                        if packet_handler_state = PARSE_TCP_PACKET14 then
2298 
                                rx_tcp_header_length <= "00"&rx_packet_rd_data(7 downto 2);
2299 
                        end if;
2300 
                        if packet_handler_state = PARSE_TCP_PACKET15 then
2301 
                                rx_tcp_flags <= rx_packet_rd_data;
2302 
                        end if;
2303 
                        if packet_handler_state = PARSE_TCP_PACKET14 then
2304 
                                rx_data_length <= unsigned(ip_packet_length);
2305 
                        elsif packet_handler_state = PARSE_TCP_PACKET15 then
2306 
                                rx_data_length <= rx_data_length - RESIZE(unsigned(rx_tcp_header_length), 16);
2307 
                        elsif packet_handler_state = PARSE_TCP_PACKET16 then
2308 
                                rx_data_length <= rx_data_length - RESIZE(unsigned(ip_packet_header_length), 16);
2309 
                        end if;
2310 
                        if packet_handler_state = PARSE_TCP_PACKET15 then
2311 
                                rx_data_start_addr <= next_protocol_start_addr;
2312 
                        elsif packet_handler_state = PARSE_TCP_PACKET16 then
2313 
                                rx_data_start_addr <= rx_data_start_addr + RESIZE(unsigned(rx_tcp_header_length), 11);
2314 
                        end if;
2315 
                        if packet_handler_state = PARSE_TCP_PACKET16 then
2316 
                                rx_tcp_window_size(15 downto 8) <= rx_packet_rd_data;
2317 
                        elsif packet_handler_state = PARSE_TCP_PACKET17 then
2318 
                                rx_tcp_window_size(7 downto 0) <= rx_packet_rd_data;
2319 
                        end if;
2320 
                        if packet_handler_state = PARSE_TCP_PACKET18 then
2321 
                                rx_tcp_checksum(15 downto 8) <= rx_packet_rd_data;
2322 
                        elsif packet_handler_state = PARSE_TCP_PACKET19 then
2323 
                                rx_tcp_checksum(7 downto 0) <= rx_packet_rd_data;
2324 
                        end if;
2325 
                        if packet_handler_state = PARSE_TCP_PACKET19 then
2326 
                                tcp_option_addr <= rx_packet_ram_rd_addr + "00000000010"; -- skip 2 blanks after checksum
2327 
                        elsif packet_handler_state = PARSE_TCP_PACKET26 then
2328 
                                tcp_option_addr <= tcp_option_addr + 1;
2329 
                        elsif packet_handler_state = PARSE_TCP_PACKET27 then
2330 
                                tcp_option_addr <= tcp_option_addr + RESIZE(rx_tcp_option_length, 11);
2331 
                        end if;
2332 
                        if packet_handler_state = PARSE_TCP_PACKET22 then
2333 
                                rx_tcp_option <= rx_packet_rd_data;
2334 
                        end if;
2335 
                        if packet_handler_state = PARSE_TCP_PACKET23 then
2336 
                                rx_tcp_option_length <= unsigned(rx_packet_rd_data);
2337 
                        end if;
2338 
                        if packet_handler_state = PARSE_TCP_PACKET24 then
2339 
                                rx_tcp_window_shift <= rx_packet_rd_data(3 downto 0);
2340 
                        end if;
2341 
                end if;
2342 
        end process;
2343 
 
2344 
        -- TODO Could disable window shift via linux kernel..?
2345 
        with rx_tcp_window_shift select
2346 
                rx_tcp_window_size_shifted <= "0000000000000000"&rx_tcp_window_size when X"0",
2347 
                                                                                                "000000000000000"&rx_tcp_window_size&"0" when X"1",
2348 
                                                                                                "00000000000000"&rx_tcp_window_size&"00" when X"2",
2349 
                                                                                                "0000000000000"&rx_tcp_window_size&"000" when X"3",
2350 
                                                                                                "000000000000"&rx_tcp_window_size&"0000" when X"4",
2351 
                                                                                                "00000000000"&rx_tcp_window_size&"00000" when X"5",
2352 
                                                                                                "0000000000"&rx_tcp_window_size&"000000" when X"6",
2353 
                                                                                                "000000000"&rx_tcp_window_size&"0000000" when X"7",
2354 
                                                                                                "00000000"&rx_tcp_window_size&"00000000" when X"8",
2355 
                                                                                                "0000000"&rx_tcp_window_size&"000000000" when X"9",
2356 
                                                                                                "000000"&rx_tcp_window_size&"0000000000" when X"A",
2357 
                                                                                                "00000"&rx_tcp_window_size&"00000000000" when X"B",
2358 
                                                                                                "0000"&rx_tcp_window_size&"000000000000" when X"C",
2359 
                                                                                                "000"&rx_tcp_window_size&"0000000000000" when X"D",
2360 
                                                                                                "00"&rx_tcp_window_size&"00000000000000" when X"E",
2361 
                                                                                                "0"&rx_tcp_window_size&"000000000000000" when others;
2362 
 
2363 
        DHCP_PROC: process(CLK_IN)
2364 
   begin
2365 
      if rising_edge(CLK_IN) then
2366 
                        if packet_handler_state = HANDLE_DHCP_ACK1 then
2367 
                                ip_addr <= dhcp_your_ip_addr;
2368 
                                client_ip_addr <= dhcp_server_ip_addr;
2369 
                        end if;
2370 
                        if tx_packet_state = INIT_DHCP_DISCOVER_METADATA then
2371 
                                expecting_dhcp_offer <= '1';
2372 
                        elsif tx_packet_state = INIT_DHCP_REQUEST_METADATA then
2373 
                                expecting_dhcp_offer <= '0';
2374 
                        elsif tx_packet_state = CANCEL_DHCP_CONNECT_ST then
2375 
                                expecting_dhcp_offer <= '0';
2376 
                        end if;
2377 
                        if tx_packet_state = INIT_DHCP_REQUEST_METADATA then
2378 
                                expecting_dhcp_ack <= '1';
2379 
                        elsif packet_handler_state = HANDLE_DHCP_ACK1 then
2380 
                                expecting_dhcp_ack <= '0';
2381 
                        elsif tx_packet_state = CANCEL_DHCP_CONNECT_ST then
2382 
                                expecting_dhcp_ack <= '0';
2383 
                        end if;
2384 
                        if eth_state = TRIGGER_DHCP_DISCOVER then
2385 
                                dhcp_addr_locked <= '0';
2386 
                        elsif packet_handler_state = HANDLE_DHCP_ACK1 then
2387 
                                dhcp_addr_locked <= '1';
2388 
                        end if;
2389 
                        if eth_state = TRIGGER_ARP_REQUEST then
2390 
                                expecting_arp_reply <= '1';
2391 
                        elsif packet_handler_state = HANDLE_ARP_REPLY1 then
2392 
                                expecting_arp_reply <= '0';
2393 
                        end if;
2394 
                        if packet_handler_state = HANDLE_ARP_REPLY7 then
2395 
                                static_addr_locked <= '1';
2396 
                        elsif tx_packet_state = INIT_ARP_REQUEST_METADATA then
2397 
                                static_addr_locked <= '0';
2398 
                        elsif tx_packet_state = CANCEL_DHCP_CONNECT_ST then
2399 
                                static_addr_locked <= '0';
2400 
                        end if;
2401 
      end if;
2402 
   end process;
2403 
 
2404 
 
2405 
--------------------- TX PACKET ------------------------------
2406 
 
2407 
        TP_SYNC_PROC: process(CLK_IN)
2408 
   begin
2409 
      if rising_edge(CLK_IN) then
2410 
                        tx_packet_state <= tx_packet_next_state;
2411 
      end if;
2412 
   end process;
2413 
 
2414 
        TP_NEXT_STATE_DECODE: process (tx_packet_state, send_arp_reply, send_arp_request, send_icmp_reply,
2415 
                                                                                                send_dhcp_discover, send_dhcp_request, frame_rd_cmplt, send_tcp_ack_packet,
2416 
                                                                                                        cancel_dhcp_connect, close_tcp_connection, cancel_tcp_connection,
2417 
                                                                                                                packet_instruction, checksum_calc_done)
2418 
   begin
2419 
      tx_packet_next_state <= tx_packet_state;  --default is to stay in current state
2420 
      case (tx_packet_state) is
2421 
         when IDLE =>
2422 
                                if send_arp_reply = '1' then
2423 
                                        tx_packet_next_state <= INIT_ARP_REPLY_METADATA;
2424 
                                elsif send_arp_request = '1' then
2425 
                                        tx_packet_next_state <= INIT_ARP_REQUEST_METADATA;
2426 
                                elsif send_icmp_reply = '1' then
2427 
                                        tx_packet_next_state <= INIT_ICMP_REPLY_METADATA;
2428 
                                elsif send_dhcp_discover = '1' then
2429 
                                        tx_packet_next_state <= INIT_DHCP_DISCOVER_METADATA;
2430 
                                elsif send_dhcp_request = '1' then
2431 
                                        tx_packet_next_state <= INIT_DHCP_REQUEST_METADATA;
2432 
                                elsif send_tcp_ack_packet = '1' then
2433 
                                        tx_packet_next_state <= INIT_TCP_PACKET_METADATA;
2434 
                                elsif cancel_dhcp_connect = '1' then
2435 
                                        tx_packet_next_state <= CANCEL_DHCP_CONNECT_ST;
2436 
                                elsif close_tcp_connection = '1' then
2437 
                                        tx_packet_next_state <= TCP_CONNECTION_CLOSED;
2438 
                                elsif cancel_tcp_connection = '1' then
2439 
                                        tx_packet_next_state <= CANCEL_TCP_CONNECTION_ST;
2440 
                                elsif send_tcp_tx_packet = '1' then
2441 
                                        tx_packet_next_state <= INIT_TCP_TX_PACKET_METADATA;
2442 
                                end if;
2443 
                        when CANCEL_DHCP_CONNECT_ST =>
2444 
                                tx_packet_next_state <= IDLE;
2445 
                        when CANCEL_TCP_CONNECTION_ST =>
2446 
                                tx_packet_next_state <= IDLE;
2447 
                        when TCP_CONNECTION_CLOSED =>
2448 
                                tx_packet_next_state <= IDLE;
2449 
                        when INIT_ARP_REPLY_METADATA =>
2450 
                                tx_packet_next_state <= READ_PACKET_BYTE0;
2451 
                        when INIT_ARP_REQUEST_METADATA =>
2452 
                                tx_packet_next_state <= READ_PACKET_BYTE0;
2453 
                        when INIT_ICMP_REPLY_METADATA =>
2454 
                                tx_packet_next_state <= READ_PACKET_BYTE0;
2455 
                        when INIT_DHCP_DISCOVER_METADATA =>
2456 
                                tx_packet_next_state <= READ_PACKET_BYTE0;
2457 
                        when INIT_DHCP_REQUEST_METADATA =>
2458 
                                tx_packet_next_state <= READ_PACKET_BYTE0;
2459 
                        when INIT_TCP_PACKET_METADATA =>
2460 
                                tx_packet_next_state <= READ_PACKET_BYTE0;
2461 
                        when INIT_TCP_TX_PACKET_METADATA =>
2462 
                                tx_packet_next_state <= READ_PACKET_BYTE0;
2463 
                        when READ_PACKET_BYTE0 =>
2464 
                                tx_packet_next_state <= READ_PACKET_BYTE1;
2465 
                        when READ_PACKET_BYTE1 =>
2466 
                                if frame_rd_cmplt = '1' then
2467 
                                        tx_packet_next_state <= HANDLE_PACKET_INSTRUCTION0;
2468 
                                end if;
2469 
                        when HANDLE_PACKET_INSTRUCTION0 =>
2470 
                                if packet_instruction = X"FF" then
2471 
                                        tx_packet_next_state <= COMPLETE;
2472 
                                elsif packet_instruction = X"17" then
2473 
                                        tx_packet_next_state <= SET_RX_PACKET_ADDR_LOWER_BYTE;
2474 
                                elsif packet_instruction = X"18" then
2475 
                                        tx_packet_next_state <= SET_RX_PACKET_ADDR_UPPER_BYTE;
2476 
                                elsif packet_instruction = X"20" then
2477 
                                        tx_packet_next_state <= SET_CHECKSUM_LENGTH_LSB;
2478 
                                elsif packet_instruction = X"21" then
2479 
                                        tx_packet_next_state <= SET_CHECKSUM_LENGTH_MSB;
2480 
                                elsif packet_instruction = X"22" then
2481 
                                        tx_packet_next_state <= SET_CHECKSUM_START_ADDR_LSB;
2482 
                                elsif packet_instruction = X"23" then
2483 
                                        tx_packet_next_state <= SET_CHECKSUM_START_ADDR_MSB;
2484 
                                elsif packet_instruction = X"24" then
2485 
                                        tx_packet_next_state <= SET_CHECKSUM_WR_ADDR_LSB;
2486 
                                elsif packet_instruction = X"25" then
2487 
                                        tx_packet_next_state <= SET_CHECKSUM_WR_ADDR_MSB;
2488 
                                elsif packet_instruction = X"26" then
2489 
                                        tx_packet_next_state <= TRIG_CHECKSUM_CALC;
2490 
                                elsif packet_instruction = X"29" then
2491 
                                        tx_packet_next_state <= MOVE_TX_PACKET_WR_ADDR;
2492 
                                elsif packet_instruction = X"2E" then
2493 
                                        tx_packet_next_state <= SET_NEW_TRANSACTION_ID;
2494 
                                elsif packet_instruction = X"50" then
2495 
                                        tx_packet_next_state <= SET_CHECKSUM_START_VAL_LSB;
2496 
                                elsif packet_instruction = X"51" then
2497 
                                        tx_packet_next_state <= SET_CHECKSUM_START_VAL_MSB;
2498 
                                elsif packet_instruction = X"52" then
2499 
                                        tx_packet_next_state <= TRIGGER_CHECKSUM_LOAD_INITIAL_VALUE;
2500 
                                elsif packet_instruction = X"57" then
2501 
                                        tx_packet_next_state <= INIT_LOAD_TX_PACKET_DATA;
2502 
                                elsif packet_instruction = X"58" then
2503 
                                        tx_packet_next_state <= SET_CHECKSUM_LENGTH_TX_PACKET_LENGTH0;
2504 
                                elsif packet_instruction = X"59" then
2505 
                                        tx_packet_next_state <= SET_CHECKSUM_INITIAL_VALUE_TX_PACKET;
2506 
                                else
2507 
                                        tx_packet_next_state <= HANDLE_PACKET_INSTRUCTION1;
2508 
                                end if;
2509 
                        when HANDLE_PACKET_INSTRUCTION1 =>
2510 
                                tx_packet_next_state <= READ_PACKET_BYTE0;
2511 
 
2512 
                        when SET_RX_PACKET_ADDR_LOWER_BYTE =>
2513 
                                tx_packet_next_state <= READ_PACKET_BYTE0;
2514 
                        when SET_RX_PACKET_ADDR_UPPER_BYTE =>
2515 
                                tx_packet_next_state <= READ_PACKET_BYTE0;
2516 
 
2517 
                        when SET_CHECKSUM_LENGTH_LSB =>
2518 
                                tx_packet_next_state <= READ_PACKET_BYTE0;
2519 
                        when SET_CHECKSUM_LENGTH_MSB =>
2520 
                                tx_packet_next_state <= READ_PACKET_BYTE0;
2521 
 
2522 
                        when SET_CHECKSUM_START_ADDR_LSB =>
2523 
                                tx_packet_next_state <= READ_PACKET_BYTE0;
2524 
                        when SET_CHECKSUM_START_ADDR_MSB =>
2525 
                                tx_packet_next_state <= READ_PACKET_BYTE0;
2526 
 
2527 
                        when SET_CHECKSUM_WR_ADDR_LSB =>
2528 
                                tx_packet_next_state <= READ_PACKET_BYTE0;
2529 
                        when SET_CHECKSUM_WR_ADDR_MSB =>
2530 
                                tx_packet_next_state <= READ_PACKET_BYTE0;
2531 
 
2532 
                        when SET_CHECKSUM_LENGTH_TX_PACKET_LENGTH0 =>
2533 
                                tx_packet_next_state <= SET_CHECKSUM_LENGTH_TX_PACKET_LENGTH1;
2534 
                        when SET_CHECKSUM_LENGTH_TX_PACKET_LENGTH1 =>
2535 
                                tx_packet_next_state <= READ_PACKET_BYTE0;
2536 
 
2537 
                        when TRIG_CHECKSUM_CALC =>
2538 
                                tx_packet_next_state <= WAIT_FOR_CHECKSUM_CMPLT;
2539 
                        when WAIT_FOR_CHECKSUM_CMPLT =>
2540 
                                if checksum_calc_done = '1' then
2541 
                                        tx_packet_next_state <= READ_PACKET_BYTE0;
2542 
                                end if;
2543 
 
2544 
                        when MOVE_TX_PACKET_WR_ADDR =>
2545 
                                tx_packet_next_state <= READ_PACKET_BYTE0;
2546 
 
2547 
                        when SET_NEW_TRANSACTION_ID =>
2548 
                                tx_packet_next_state <= READ_PACKET_BYTE0;
2549 
 
2550 
                        when SET_CHECKSUM_START_VAL_LSB =>
2551 
                                tx_packet_next_state <= READ_PACKET_BYTE0;
2552 
                        when SET_CHECKSUM_START_VAL_MSB =>
2553 
                                tx_packet_next_state <= READ_PACKET_BYTE0;
2554 
                        when TRIGGER_CHECKSUM_LOAD_INITIAL_VALUE =>
2555 
                                tx_packet_next_state <= READ_PACKET_BYTE0;
2556 
                        when SET_CHECKSUM_INITIAL_VALUE_TX_PACKET =>
2557 
                                tx_packet_next_state <= READ_PACKET_BYTE0;
2558 
 
2559 
                        when INIT_LOAD_TX_PACKET_DATA =>
2560 
                                tx_packet_next_state <= LOAD_TX_PACKET_DATA;
2561 
                        when LOAD_TX_PACKET_DATA =>
2562 
                                if tx_packet_data_counter = X"001" then
2563 
                                        tx_packet_next_state <= HANDLE_PACKET_INSTRUCTION1;
2564 
                                end if;
2565 
 
2566 
                        when COMPLETE =>
2567 
                                tx_packet_next_state <= IDLE;
2568 
 
2569 
                end case;
2570 
        end process;
2571 
 
2572 
        packet_instruction <= frame_data(15 downto 8);
2573 
 
2574 
        with packet_instruction(6 downto 0) select
2575 
                packet_data <= frame_data(7 downto 0)                                                    when "000"&X"0",
2576 
                                                        mac_addr(7 downto 0)                                                     when "000"&X"1",
2577 
                                                        mac_addr(15 downto 8)                                                   when "000"&X"2",
2578 
                                                        mac_addr(23 downto 16)                                                  when "000"&X"3",
2579 
                                                        mac_addr(31 downto 24)                                                  when "000"&X"4",
2580 
                                                        mac_addr(39 downto 32)                                                  when "000"&X"5",
2581 
                                                        mac_addr(47 downto 40)                                                  when "000"&X"6",
2582 
                                                        rx_packet_source_mac(7 downto 0)                         when "000"&X"7",
2583 
                                                        rx_packet_source_mac(15 downto 8)                       when "000"&X"8",
2584 
                                                        rx_packet_source_mac(23 downto 16)                      when "000"&X"9",
2585 
                                                        rx_packet_source_mac(31 downto 24)                      when "000"&X"A",
2586 
                                                        rx_packet_source_mac(39 downto 32)                      when "000"&X"B",
2587 
                                                        rx_packet_source_mac(47 downto 40)                      when "000"&X"C",
2588 
                                                        ip_addr(7 downto 0)                                                              when "000"&X"D",
2589 
                                                        ip_addr(15 downto 8)                                                    when "000"&X"E",
2590 
                                                        ip_addr(23 downto 16)                                                   when "000"&X"F",
2591 
                                                        ip_addr(31 downto 24)                                                   when "001"&X"0",
2592 
                                                        arp_source_ip_addr(7 downto 0)                           when "001"&X"1",
2593 
                                                        arp_source_ip_addr(15 downto 8)                                 when "001"&X"2",
2594 
                                                        arp_source_ip_addr(23 downto 16)                        when "001"&X"3",
2595 
                                                        arp_source_ip_addr(31 downto 24)                        when "001"&X"4",
2596 
                                                        ip_identification(7 downto 0)                                    when "001"&X"5",
2597 
                                                        ip_identification(15 downto 8)                                  when "001"&X"6",
2598 
                                                        X"00"                                                                                                   when "001"&X"7", -- set rx read lower byte
2599 
                                                        X"00"                                                                                                   when "001"&X"8", -- set rx read upper byte
2600 
                                                        rx_packet_rd_data2                                                              when "001"&X"9",
2601 
                                                        cloud_ip_addr(7 downto 0)                                                when "001"&X"A",
2602 
                                                        cloud_ip_addr(15 downto 8)                                              when "001"&X"B",
2603 
                                                        cloud_ip_addr(23 downto 16)                                     when "001"&X"C",
2604 
                                                        cloud_ip_addr(31 downto 24)                                     when "001"&X"D",
2605 
                                                        X"00"                                                                                                   when "010"&X"0", -- set checksum length lsb
2606 
                                                        X"00"                                                                                                   when "010"&X"1", -- set checksum length msb
2607 
                                                        X"00"                                                                                                   when "010"&X"2", -- set checksum start addr lsb
2608 
                                                        X"00"                                                                                                   when "010"&X"3", -- set checksum start addr msb
2609 
                                                        X"00"                                                                                                   when "010"&X"4", -- set checksum wr addr lsb
2610 
                                                        X"00"                                                                                                   when "010"&X"5", -- set checksum wr addr msb
2611 
                                                        X"00"                                                                                                   when "010"&X"6", -- trigger checksum calc
2612 
                                                        checksum(7 downto 0)                                                     when "010"&X"7",
2613 
                                                        checksum(15 downto 8)                                                   when "010"&X"8",
2614 
                                                        X"00"                                                                                                   when "010"&X"9", -- set tx write addr to checksum wr addr
2615 
                                                        dhcp_transaction_id(7 downto 0)                          when "010"&X"A",
2616 
                                                        dhcp_transaction_id(15 downto 8)                                when "010"&X"B",
2617 
                                                        dhcp_transaction_id(23 downto 16)                       when "010"&X"C",
2618 
                                                        dhcp_transaction_id(31 downto 24)                       when "010"&X"D",
2619 
                                                        X"00"                                                                                                   when "010"&X"E", -- set new transaction ID
2620 
                                                        dhcp_server_ip_addr(7 downto 0)                          when "010"&X"F",
2621 
                                                        dhcp_server_ip_addr(15 downto 8)                                when "011"&X"0",
2622 
                                                        dhcp_server_ip_addr(23 downto 16)                       when "011"&X"1",
2623 
                                                        dhcp_server_ip_addr(31 downto 24)                       when "011"&X"2",
2624 
                                                        dhcp_your_ip_addr(7 downto 0)                                    when "011"&X"3",
2625 
                                                        dhcp_your_ip_addr(15 downto 8)                          when "011"&X"4",
2626 
                                                        dhcp_your_ip_addr(23 downto 16)                         when "011"&X"5",
2627 
                                                        dhcp_your_ip_addr(31 downto 24)                         when "011"&X"6",
2628 
                                                        client_ip_addr(7 downto 0)                                               when "011"&X"7",
2629 
                                                        client_ip_addr(15 downto 8)                                     when "011"&X"8",
2630 
                                                        client_ip_addr(23 downto 16)                                    when "011"&X"9",
2631 
                                                        client_ip_addr(31 downto 24)                                    when "011"&X"A",
2632 
                                                        client_mac_addr(7 downto 0)                                      when "011"&X"B",
2633 
                                                        client_mac_addr(15 downto 8)                                    when "011"&X"C",
2634 
                                                        client_mac_addr(23 downto 16)                           when "011"&X"D",
2635 
                                                        client_mac_addr(31 downto 24)                           when "011"&X"E",
2636 
                                                        client_mac_addr(39 downto 32)                           when "011"&X"F",
2637 
                                                        client_mac_addr(47 downto 40)                           when "100"&X"0",
2638 
                                                        listen_port(7 downto 0)                                                  when "100"&X"1",
2639 
                                                        listen_port(15 downto 8)                                                when "100"&X"2",
2640 
                                                        client_port(7 downto 0)                                                  when "100"&X"3",
2641 
                                                        client_port(15 downto 8)                                                when "100"&X"4",
2642 
                                                        slv(tcp_sequence_number(7 downto 0))             when "100"&X"5",
2643 
                                                        slv(tcp_sequence_number(15 downto 8))           when "100"&X"6",
2644 
                                                        slv(tcp_sequence_number(23 downto 16))          when "100"&X"7",
2645 
                                                        slv(tcp_sequence_number(31 downto 24))          when "100"&X"8",
2646 
                                                        slv(tcp_acknowledge_number(7 downto 0))                  when "100"&X"9",
2647 
                                                        slv(tcp_acknowledge_number(15 downto 8))                        when "100"&X"A",
2648 
                                                        slv(tcp_acknowledge_number(23 downto 16))                       when "100"&X"B",
2649 
                                                        slv(tcp_acknowledge_number(31 downto 24))                       when "100"&X"C",
2650 
                                                        tcp_flags(7 downto 0)                                                                    when "100"&X"D",
2651 
                                                        slv(window_size(7 downto 0))                                                     when "100"&X"E",
2652 
                                                        slv(X"0"&window_size(11 downto 8))                                       when "100"&X"F",
2653 
                                                        X"00"                                                                                                                   when "101"&X"0", -- Set initial checksum value
2654 
                                                        X"00"                                                                                                                   when "101"&X"1", -- Set initial checksum value
2655 
                                                        X"00"                                                                                                                   when "101"&X"2", -- Load initial checksum value
2656 
                                                        slv(tcp_ip_identification(7 downto 0))                           when "101"&X"3",
2657 
                                                        slv(tcp_ip_identification(15 downto 8))                 when "101"&X"4",
2658 
                                                        slv(tx_total_packet_length(7 downto 0))                  when "101"&X"5", -- Data packet length + headers
2659 
                                                        slv(X"0"&tx_total_packet_length(11 downto 8))    when "101"&X"6", -- Data packet length + headers
2660 
                                                        tcp_tx_data                                                                                                     when "101"&X"7", -- TX Data
2661 
                                                        X"00"                                                                                                                   when "101"&X"8", -- Set checksum length to tx data length
2662 
                                                        X"00"                                                                                                                   when "101"&X"9", -- Set initial checksum value to length + protocol (6)
2663 
                                                        X"00"                                                                                                                   when others;
2664 
 
2665 
        tcp_sequence_number_p1 <= tcp_sequence_number + 1;
2666 
 
2667 
        METADATA_PTOC: process(CLK_IN)
2668 
        begin
2669 
                if rising_edge(CLK_IN) then
2670 
                        ip_identification <= lfsr_val(15 downto 0);
2671 
                        if tx_packet_state = SET_NEW_TRANSACTION_ID then
2672 
                                dhcp_transaction_id <= lfsr_val;
2673 
                        end if;
2674 
                        if packet_handler_state = CHECK_TCP_SYN_PACKET0 then
2675 
                                tcp_ip_identification <= unsigned(lfsr_val(15 downto 0));
2676 
                        elsif packet_handler_state = CHECK_TCP_PSH_ACK_PACKET2 then
2677 
                                tcp_ip_identification <= tcp_ip_identification + 1;
2678 
                        end if;
2679 
                        if packet_handler_state = PARSE_TCP_PACKET4 and tcp_connection_active = '0' then
2680 
                                client_port <= rx_tcp_source_port;
2681 
                        end if;
2682 
                        if packet_handler_state = CHECK_TCP_SYN_PACKET0 then
2683 
                                tcp_sequence_number <= unsigned(lfsr_val);
2684 
                        elsif packet_handler_state = PARSE_TCP_PACKET0 and sent_syn_ack = '1' then
2685 
                                tcp_sequence_number <= tcp_sequence_number + 1;
2686 
                        elsif packet_handler_state = TRIGGER_TCP_PSH_ACK3 then
2687 
                                tcp_sequence_number <= tcp_sequence_number + RESIZE(tx_bytes_to_send, 32);
2688 
                        end if;
2689 
                        if packet_handler_state = CHECK_TCP_SYN_PACKET0 then
2690 
                                tcp_acknowledge_number <= unsigned(rx_tcp_seq_number) + 1;
2691 
                        elsif packet_handler_state = TRIGGER_TCP_ACK0 and fin_received = '1' then
2692 
                                tcp_acknowledge_number <= tcp_acknowledge_number + 1;
2693 
                        elsif packet_handler_state = CHECK_TCP_PSH_ACK_PACKET3 then
2694 
                                tcp_acknowledge_number <= tcp_acknowledge_number + RESIZE(rx_data_length, 32);
2695 
                        end if;
2696 
                        if packet_handler_state = TRIGGER_TCP_ACK0 then
2697 
                                if fin_received = '1' then
2698 
                                        tcp_flags <= C_tcp_fin_ack_flags;
2699 
                                elsif syn_ack_packet = '1' then
2700 
                                        tcp_flags <= C_tcp_syn_ack_flags;
2701 
                                else
2702 
                                        tcp_flags <= C_tcp_ack_flags;
2703 
                                end if;
2704 
                        elsif packet_handler_state = TRIGGER_TCP_PSH_ACK2 then
2705 
                                tcp_flags <= C_tcp_psh_ack_flags;
2706 
                        end if;
2707 
                        if packet_handler_state = TRIGGER_TCP_ACK0 then
2708 
                                window_size <= X"FFF" - unsigned(tcp_rd_data_count);
2709 
                        elsif packet_handler_state = TRIGGER_TCP_ACK1 then
2710 
                                window_size <= X"FFF" - unsigned(tcp_rd_data_count);
2711 
                        end if;
2712 
                        if packet_handler_state = CHECK_TCP_SYN_PACKET0 then
2713 
                                fin_received <= '0';
2714 
                        elsif rx_tcp_flags(0) = '1' then
2715 
                                fin_received <= '1';
2716 
                        end if;
2717 
                        fin_received_p <= fin_received;
2718 
                        if fin_received = '1' and fin_received_p = '0' then
2719 
                                trigger_fin_ack <= '1';
2720 
                        else
2721 
                                trigger_fin_ack <= '0';
2722 
                        end if;
2723 
                        if packet_handler_state = CHECK_TCP_SYN_PACKET0 then
2724 
                                syn_ack_packet <= '1';
2725 
                        elsif packet_handler_state = TRIGGER_TCP_ACK0 then
2726 
                                syn_ack_packet <= '0';
2727 
                        end if;
2728 
                        if packet_handler_state = TRIGGER_TCP_ACK0 and syn_ack_packet = '1' then
2729 
                                sent_syn_ack <= '1';
2730 
                        elsif packet_handler_state = CHECK_TCP_PSH_ACK_PACKET0 then
2731 
                                sent_syn_ack <= '0';
2732 
                        end if;
2733 
                        if packet_handler_state = CHECK_TCP_SYN_PACKET0 then
2734 
                                tcp_connection_active <= '1';
2735 
                        elsif fin_received = '1' then
2736 
                                tcp_connection_active <= '0';
2737 
                        elsif trigger_close_connection = '1' then
2738 
                                tcp_connection_active <= '0';
2739 
                        end if;
2740 
                        if packet_handler_state = TRIGGER_TCP_PSH_ACK0 then
2741 
                                if unsigned(tcp_wr_data_count) > X"580" then
2742 
                                        tx_bytes_to_send <= X"580";
2743 
                                else
2744 
                                        tx_bytes_to_send <= unsigned(tcp_wr_data_count);
2745 
                                end if;
2746 
                        end if;
2747 
                        if packet_handler_state = TRIGGER_TCP_PSH_ACK1 then
2748 
                                tx_total_packet_length <= tx_bytes_to_send + X"030"; -- IP Header length (20 Bytes) + TCP Header length (28 Bytes)
2749 
                        end if;
2750 
                        if packet_handler_state = TRIGGER_TCP_PSH_ACK1 then
2751 
                                tx_total_packet_length_inc_mac <= tx_bytes_to_send + X"03E"; -- IP Header length (20 Bytes) + TCP Header length (28 Bytes) + MAC length (14 bytes)
2752 
                        end if;
2753 
                        if packet_handler_state = TRIGGER_TCP_PSH_ACK1 then
2754 
                                tx_total_packet_length_checksum <= tx_bytes_to_send + X"022"; --  TCP Header length (28 Bytes) + Protocol (value=6)
2755 
                        end if;
2756 
                        -- TODO need to 'lock' tx logic (so previous tx packet isn't overwritten by arp or something)
2757 
                        -- Can be achieved by only responding to TCP packets when tx_packet_no_ack_timeout > X"1"
2758 
                        if packet_handler_state = TRIGGER_TCP_PSH_ACK3 then
2759 
                                tx_packets_no_ack <= tx_packets_no_ack + 1;
2760 
                        elsif packet_handler_state = CHECK_TCP_PSH_ACK_PACKET2 then
2761 
                                tx_packets_no_ack <= X"0";
2762 
                        end if;
2763 
                        if tx_packets_no_ack > X"1" then
2764 
                                tx_packet_no_ack_timeout <= tx_packet_no_ack_timeout - 1;
2765 
                        else
2766 
                                tx_packet_no_ack_timeout <= C_100ms;
2767 
                        end if;
2768 
                        if tx_packets_no_ack < X"2" then
2769 
                                tx_packet_timeout_counter <= X"00";
2770 
                        elsif tx_packet_no_ack_timeout = X"000000" then
2771 
                                tx_packet_timeout_counter <= tx_packet_timeout_counter + 1;
2772 
                        end if;
2773 
                        tx_packet_timeout_counter_prev <= tx_packet_timeout_counter;
2774 
                        if tx_packet_timeout_counter = X"01" and tx_packet_timeout_counter_prev = X"00" then
2775 
                                trigger_send_prev_packet <= '1';
2776 
                        elsif tx_packet_timeout_counter = X"03" and tx_packet_timeout_counter_prev = X"02" then
2777 
                                trigger_send_prev_packet <= '1';
2778 
                        elsif tx_packet_timeout_counter = X"07" and tx_packet_timeout_counter_prev = X"06" then
2779 
                                trigger_send_prev_packet <= '1';
2780 
                        elsif tx_packet_timeout_counter = X"0F" and tx_packet_timeout_counter_prev = X"0E" then
2781 
                                trigger_send_prev_packet <= '1';
2782 
                        else
2783 
                                trigger_send_prev_packet <= '0';
2784 
                        end if;
2785 
                        if tx_packet_timeout_counter = X"1F" and tx_packet_timeout_counter_prev = X"1E" then
2786 
                                trigger_close_connection <= '1';
2787 
                        else
2788 
                                trigger_close_connection <= '0';
2789 
                        end if;
2790 
                end if;
2791 
        end process;
2792 
 
2793 
        FRAME_ADDR_LENGTH_PROC: process(CLK_IN)
2794 
   begin
2795 
      if rising_edge(CLK_IN) then
2796 
                        if tx_packet_state = INIT_ARP_REPLY_METADATA then
2797 
                                tx_packet_frame_addr <= unsigned(C_arp_reply_frame_addr);
2798 
                        elsif tx_packet_state = INIT_ARP_REQUEST_METADATA then
2799 
                                tx_packet_frame_addr <= unsigned(C_arp_request_frame_addr);
2800 
                        elsif tx_packet_state = INIT_ICMP_REPLY_METADATA then
2801 
                                tx_packet_frame_addr <= unsigned(C_icmp_reply_frame_addr);
2802 
                        elsif tx_packet_state = INIT_DHCP_DISCOVER_METADATA then
2803 
                                tx_packet_frame_addr <= unsigned(C_dhcp_discover_frame_addr);
2804 
                        elsif tx_packet_state = INIT_DHCP_REQUEST_METADATA then
2805 
                                tx_packet_frame_addr <= unsigned(C_dhcp_request_frame_addr);
2806 
                        elsif tx_packet_state = INIT_TCP_PACKET_METADATA then
2807 
                                tx_packet_frame_addr <= unsigned(C_tcp_packet_frame_addr);
2808 
                        elsif tx_packet_state = INIT_TCP_TX_PACKET_METADATA then
2809 
                                tx_packet_frame_addr <= unsigned(C_tcp_tx_packet_frame_addr);
2810 
                        elsif tx_packet_state = IDLE then
2811 
                                tx_packet_frame_addr <= tx_packet_frame_addr;
2812 
                        elsif tx_packet_state = READ_PACKET_BYTE0 then
2813 
                                tx_packet_frame_addr <= tx_packet_frame_addr;
2814 
                        elsif tx_packet_state = READ_PACKET_BYTE1 then
2815 
                                tx_packet_frame_addr <= tx_packet_frame_addr;
2816 
                        elsif tx_packet_state = HANDLE_PACKET_INSTRUCTION0 then
2817 
                                tx_packet_frame_addr <= tx_packet_frame_addr;
2818 
                        elsif tx_packet_state = WAIT_FOR_CHECKSUM_CMPLT then
2819 
                                tx_packet_frame_addr <= tx_packet_frame_addr;
2820 
                        elsif tx_packet_state = COMPLETE then
2821 
                                tx_packet_frame_addr <= tx_packet_frame_addr;
2822 
                        elsif tx_packet_state = INIT_LOAD_TX_PACKET_DATA then
2823 
                                tx_packet_frame_addr <= tx_packet_frame_addr;
2824 
                        elsif tx_packet_state = LOAD_TX_PACKET_DATA then
2825 
                                tx_packet_frame_addr <= tx_packet_frame_addr;
2826 
                        elsif tx_packet_state = SET_CHECKSUM_LENGTH_TX_PACKET_LENGTH0 then
2827 
                                tx_packet_frame_addr <= tx_packet_frame_addr;
2828 
                        else
2829 
                                tx_packet_frame_addr <= tx_packet_frame_addr + 1;
2830 
                        end if;
2831 
                        if tx_packet_state = INIT_ARP_REPLY_METADATA then
2832 
                                tx_packet_length <= unsigned(C_arp_reply_length);
2833 
                        elsif tx_packet_state = INIT_ARP_REQUEST_METADATA then
2834 
                                tx_packet_length <= unsigned(C_arp_request_length);
2835 
                        elsif tx_packet_state = INIT_ICMP_REPLY_METADATA then
2836 
                                tx_packet_length <= unsigned(C_icmp_reply_length);
2837 
                        elsif tx_packet_state = INIT_DHCP_DISCOVER_METADATA then
2838 
                                tx_packet_length <= unsigned(C_dhcp_discover_length);
2839 
                        elsif tx_packet_state = INIT_DHCP_REQUEST_METADATA then
2840 
                                tx_packet_length <= unsigned(C_dhcp_request_length);
2841 
                        elsif tx_packet_state = INIT_TCP_PACKET_METADATA then
2842 
                                tx_packet_length <= unsigned(C_tcp_packet_length);
2843 
                        elsif tx_packet_state = INIT_TCP_TX_PACKET_METADATA then
2844 
                                tx_packet_length <= RESIZE(unsigned(tx_total_packet_length_inc_mac), 16);
2845 
                        end if;
2846 
                        if tx_packet_state = INIT_ARP_REPLY_METADATA then
2847 
                                tx_packet_end_pointer <= tx_base_addr + unsigned(C_arp_reply_length);
2848 
                                prev_tx_packet_end_pointer <= tx_packet_end_pointer;
2849 
                        elsif tx_packet_state = INIT_ARP_REQUEST_METADATA then
2850 
                                tx_packet_end_pointer <= tx_base_addr + unsigned(C_arp_request_length);
2851 
                                prev_tx_packet_end_pointer <= tx_packet_end_pointer;
2852 
                        elsif tx_packet_state = INIT_ICMP_REPLY_METADATA then
2853 
                                tx_packet_end_pointer <= tx_base_addr + unsigned(C_icmp_reply_length);
2854 
                                prev_tx_packet_end_pointer <= tx_packet_end_pointer;
2855 
                        elsif tx_packet_state = INIT_DHCP_DISCOVER_METADATA then
2856 
                                tx_packet_end_pointer <= tx_base_addr + unsigned(C_dhcp_discover_length);
2857 
                                prev_tx_packet_end_pointer <= tx_packet_end_pointer;
2858 
                        elsif tx_packet_state = INIT_DHCP_REQUEST_METADATA then
2859 
                                tx_packet_end_pointer <= tx_base_addr + unsigned(C_dhcp_discover_length);
2860 
                                prev_tx_packet_end_pointer <= tx_packet_end_pointer;
2861 
                        elsif tx_packet_state = INIT_TCP_PACKET_METADATA then
2862 
                                tx_packet_end_pointer <= tx_base_addr + unsigned(C_tcp_packet_length);
2863 
                                prev_tx_packet_end_pointer <= tx_packet_end_pointer;
2864 
                        elsif tx_packet_state = INIT_TCP_TX_PACKET_METADATA then
2865 
                                tx_packet_end_pointer <= tx_base_addr + RESIZE(unsigned(tx_total_packet_length_inc_mac), 16);
2866 
                                prev_tx_packet_end_pointer <= tx_packet_end_pointer;
2867 
                        end if;
2868 
                        if tx_packet_state = IDLE then
2869 
                                doing_tx_packet_config <= '0';
2870 
                        else
2871 
                                doing_tx_packet_config <= '1';
2872 
                        end if;
2873 
                        if tx_packet_state = IDLE then
2874 
                                tx_packet_ram_we_addr_buf <= "00000000000";
2875 
                        elsif tx_packet_state = HANDLE_PACKET_INSTRUCTION1 then
2876 
                                tx_packet_ram_we_addr_buf <= tx_packet_ram_we_addr_buf + 1;
2877 
                        elsif tx_packet_state = LOAD_TX_PACKET_DATA then
2878 
                                tx_packet_ram_we_addr_buf <= tx_packet_ram_we_addr_buf + 1;
2879 
                        elsif tx_packet_state = MOVE_TX_PACKET_WR_ADDR then
2880 
                                tx_packet_ram_we_addr_buf <= unsigned(checksum_wr_addr);
2881 
                        end if;
2882 
                        if tx_packet_state = COMPLETE then
2883 
                                tx_packet_ready_for_transmission <= '1';
2884 
                        elsif eth_state = HANDLE_TX_TRANSMIT22 then
2885 
                                tx_packet_ready_for_transmission <= '0';
2886 
                        end if;
2887 
                        if tx_packet_state = SET_RX_PACKET_ADDR_LOWER_BYTE then
2888 
                                rx_packet_rd2_addr(7 downto 0) <= unsigned(frame_data(7 downto 0));
2889 
                        elsif tx_packet_state = SET_RX_PACKET_ADDR_UPPER_BYTE then
2890 
                                rx_packet_rd2_addr(10 downto 8) <= unsigned(frame_data(2 downto 0));
2891 
                        elsif tx_packet_state = HANDLE_PACKET_INSTRUCTION1 then
2892 
                                rx_packet_rd2_addr <= rx_packet_rd2_addr + 1;
2893 
                        elsif tx_packet_state = LOAD_TX_PACKET_DATA then
2894 
                                rx_packet_rd2_addr <= rx_packet_rd2_addr + 1;
2895 
                        end if;
2896 
      end if;
2897 
   end process;
2898 
 
2899 
        tx_base_addr <= C_tx_base_addr1 when tx_base_addr_select = '0' else C_tx_base_addr2;
2900 
 
2901 
        process(CLK_IN)
2902 
        begin
2903 
                if rising_edge(CLK_IN) then
2904 
                        if eth_state = HANDLE_TX_TRANSMIT22 or eth_state = HANDLE_TX_TRANSMIT_PREV16 then
2905 
                                tx_base_addr_select <= not(tx_base_addr_select);
2906 
                        end if;
2907 
                        if eth_state = WAIT_FOR_TRANSMIT_CMPLT then
2908 
                                tx_timeout_counter <= tx_timeout_counter - 1;
2909 
                        else
2910 
                                tx_timeout_counter <= C_20ms;
2911 
                        end if;
2912 
                end if;
2913 
        end process;
2914 
 
2915 
        tx_packet_ram_data <= packet_data;
2916 
        tx_packet_ram_we <= '1' when (tx_packet_state = HANDLE_PACKET_INSTRUCTION1) or (tx_packet_state = LOAD_TX_PACKET_DATA) else '0';
2917 
        tx_packet_config_cmplt <= '1' when tx_packet_state = COMPLETE else '0';
2918 
 
2919 
        tx_packet_ram_we_addr <= unsigned(checksum_addr) when (tx_packet_state = WAIT_FOR_CHECKSUM_CMPLT) else tx_packet_ram_we_addr_buf;
2920 
 
2921 
        TX_PACKET_RAM : TDP_RAM
2922 
                Generic Map (   G_DATA_A_SIZE   => tx_packet_ram_data'length,
2923 
                                                        G_ADDR_A_SIZE   => tx_packet_ram_we_addr'length,
2924 
                                                        G_RELATION              => 0, --log2(SIZE_A/SIZE_B)
2925 
                                                        G_INIT_ZERO             => true,
2926 
                                                        G_INIT_FILE             => "")
2927 
                Port Map ( CLK_A_IN     => CLK_IN,
2928 
                                 WE_A_IN                => tx_packet_ram_we,
2929 
                                 ADDR_A_IN              => slv(tx_packet_ram_we_addr),
2930 
                                 DATA_A_IN              => tx_packet_ram_data,
2931 
                                 DATA_A_OUT             => tx_packet_rd_data2,
2932 
                                 CLK_B_IN               => CLK_IN,
2933 
                                 WE_B_IN                => '0',
2934 
                                 ADDR_B_IN              => slv(tx_packet_ram_rd_addr),
2935 
                                 DATA_B_IN              => X"00",
2936 
                                 DATA_B_OUT     => tx_packet_rd_data);
2937 
 
2938 
        CHECKSUM_METADATA_PROC: process(CLK_IN)
2939 
   begin
2940 
      if rising_edge(CLK_IN) then
2941 
                        if tx_packet_state = SET_CHECKSUM_LENGTH_LSB then
2942 
                                checksum_count(7 downto 0) <= unsigned(frame_data(7 downto 0));
2943 
                        elsif tx_packet_state = SET_CHECKSUM_LENGTH_MSB then
2944 
                                checksum_count(10 downto 8) <= unsigned(frame_data(2 downto 0));
2945 
                        elsif tx_packet_state = SET_CHECKSUM_LENGTH_TX_PACKET_LENGTH0 then
2946 
                                checksum_count(10 downto 0) <= unsigned('0'&tx_bytes_to_send(10 downto 1)) + "00000010010";
2947 
                        elsif tx_packet_state = SET_CHECKSUM_LENGTH_TX_PACKET_LENGTH1 then
2948 
                                checksum_count(10 downto 0) <= checksum_count(10 downto 0) + ("0000000000"&tx_bytes_to_send(0));
2949 
                        end if;
2950 
                        if tx_packet_state = SET_CHECKSUM_LENGTH_TX_PACKET_LENGTH1 then
2951 
                                checksum_odd_length <= tx_bytes_to_send(0);
2952 
                        elsif tx_packet_state = MOVE_TX_PACKET_WR_ADDR then -- clear odd flag before next checksum is calcd
2953 
                                checksum_odd_length <= '0';
2954 
                        end if;
2955 
                        if tx_packet_state = SET_CHECKSUM_START_ADDR_LSB then
2956 
                                checksum_start_addr(7 downto 0) <= frame_data(7 downto 0);
2957 
                        elsif tx_packet_state = SET_CHECKSUM_START_ADDR_MSB then
2958 
                                checksum_start_addr(10 downto 8) <= frame_data(2 downto 0);
2959 
                        end if;
2960 
                        if tx_packet_state = SET_CHECKSUM_WR_ADDR_LSB then
2961 
                                checksum_wr_addr(7 downto 0) <= frame_data(7 downto 0);
2962 
                        elsif tx_packet_state = SET_CHECKSUM_WR_ADDR_MSB then
2963 
                                checksum_wr_addr(10 downto 8) <= frame_data(2 downto 0);
2964 
                        end if;
2965 
                        if tx_packet_state = SET_CHECKSUM_START_VAL_LSB then
2966 
                                checksum_initial_value(7 downto 0) <= frame_data(7 downto 0);
2967 
                        elsif tx_packet_state = SET_CHECKSUM_INITIAL_VALUE_TX_PACKET then
2968 
                                checksum_initial_value(7 downto 0) <= slv(tx_total_packet_length_checksum(7 downto 0));
2969 
                        end if;
2970 
                        if tx_packet_state = SET_CHECKSUM_START_VAL_MSB then
2971 
                                checksum_initial_value(15 downto 8) <= frame_data(7 downto 0);
2972 
                        elsif tx_packet_state = SET_CHECKSUM_INITIAL_VALUE_TX_PACKET then
2973 
                                checksum_initial_value(11 downto 8) <= slv(tx_total_packet_length_checksum(11 downto 8));
2974 
                                checksum_initial_value(15 downto 12) <= X"0";
2975 
                        end if;
2976 
                        if tx_packet_state = TRIGGER_CHECKSUM_LOAD_INITIAL_VALUE then
2977 
                                checksum_set_initial_value <= '1';
2978 
                        else
2979 
                                checksum_set_initial_value <= '0';
2980 
                        end if;
2981 
                        if tx_packet_state = INIT_LOAD_TX_PACKET_DATA then
2982 
                                tx_packet_data_counter <= tx_bytes_to_send - 1;
2983 
                        else
2984 
                                tx_packet_data_counter <= tx_packet_data_counter - 1;
2985 
                        end if;
2986 
                end if;
2987 
        end process;
2988 
 
2989 
        calc_checksum <= '1' when tx_packet_state = TRIG_CHECKSUM_CALC else '0';
2990 
 
2991 
        checksum_calc_mod : checksum_calc
2992 
    Port Map ( CLK_IN                                           => CLK_IN,
2993 
                                        RST_IN                                          => '0',
2994 
                                        CHECKSUM_CALC_IN                        => calc_checksum,
2995 
                                        START_ADDR_IN                           => checksum_start_addr,
2996 
                                        COUNT_IN                                        => slv(checksum_count),
2997 
                                        VALUE_IN                                        => tx_packet_rd_data2,
2998 
                                        VALUE_ADDR_OUT                  => checksum_addr,
2999 
                                        CHECKSUM_INIT_IN                        => checksum_initial_value,
3000 
                                        CHECKSUM_SET_INIT_IN            => checksum_set_initial_value,
3001 
                                        CHECKSUM_ODD_LENGTH_IN  => checksum_odd_length,
3002 
                                        CHECKSUM_OUT                            => checksum,
3003 
                                        CHECKSUM_DONE_OUT               => checksum_calc_done);
3004 
 
3005 
------------------- PACKET DEFINITION ------------------------
3006 
 
3007 
        Packet_Definition_Mod : Packet_Definition
3008 
          Port Map (
3009 
                 clka   => CLK_IN,
3010 
                 addra  => packet_definition_addr,
3011 
                 douta  => packet_definition_data);
3012 
 
3013 
------------------------- SPI --------------------------------
3014 
 
3015 
        spi_mod_inst : spi_mod
3016 
                Port Map (      CLK_IN                          => CLK_IN,
3017 
                                                RST_IN                          => '0',
3018 
 
3019 
                                                WR_CONTINUOUS_IN        => spi_wr_continuous,
3020 
                                                WE_IN                           => spi_we,
3021 
                                                WR_ADDR_IN                      => spi_wr_addr,
3022 
                                                WR_DATA_IN                      => spi_wr_data,
3023 
                                                WR_DATA_CMPLT_OUT       => spi_wr_cmplt,
3024 
 
3025 
                                                RD_CONTINUOUS_IN        => spi_rd_continuous,
3026 
                                                RD_IN                                   => spi_rd,
3027 
                                                RD_WIDTH_IN             => spi_rd_width,
3028 
                                                RD_ADDR_IN                      => spi_rd_addr,
3029 
                                                RD_DATA_OUT             => spi_data_rd,
3030 
                                                RD_DATA_CMPLT_OUT       => spi_rd_cmplt,
3031 
 
3032 
                                                SLOW_CS_EN_IN           => slow_cs_en,
3033 
                                                OPER_CMPLT_POST_CS_OUT => spi_oper_cmplt,
3034 
 
3035 
                                                SDI_OUT                         => SDI_OUT,
3036 
                                                SDO_IN                          => SDO_IN,
3037 
                                                SCLK_OUT                                => SCLK_OUT,
3038 
                                                CS_OUT                          => CS_OUT);
3039 
 
3040 
------------------------- LFSR -------------------------------
3041 
 
3042 
        lfsr32_mod_inst : lfsr32_mod
3043 
                Port Map (      CLK_IN          => CLK_IN,
3044 
                                                SEED_IN                 => X"00000000",
3045 
                                                SEED_EN_IN      => '0',
3046 
                                                VAL_OUT                 => lfsr_val);
3047 
 
3048 
--------------------- TCP RX DATA ----------------------------
3049 
 
3050 
        TCP_CONNECTION_ACTIVE_OUT <= tcp_connection_active;
3051 
 
3052 
        tcp_data_rd_en <= TCP_RD_DATA_EN_IN;
3053 
        TCP_RD_DATA_AVAIL_OUT <= not(tcp_rd_data_available);
3054 
        TCP_RD_DATA_OUT <= tcp_rx_data_rd_data;
3055 
 
3056 
        tcp_rx_data_we <= '1' when (packet_handler_next_state = READ_TCP_RX_DATA) else '0';
3057 
 
3058 
        TCP_RX_FIFO : TCP_FIFO
3059 
          PORT MAP (
3060 
                 clk                            => CLK_IN,
3061 
                 din                            => rx_packet_rd_data,
3062 
                 wr_en                  => tcp_rx_data_we,
3063 
                 rd_en                  => tcp_data_rd_en,
3064 
                 dout                   => tcp_rx_data_rd_data,
3065 
                 full                   => open,
3066 
                 almost_full    => open,
3067 
                 empty                  => tcp_rd_data_available,
3068 
                 data_count     => tcp_rd_data_count);
3069 
 
3070 
--------------------- TCP TX DATA ----------------------------
3071 
 
3072 
        TCP_WR_DATA_POSSIBLE_OUT <= tcp_wr_data_possible;
3073 
        tcp_wr_data_possible <= '1' when tcp_wr_data_count < X"FA0" else '0';
3074 
 
3075 
        tcp_wr_data_en <= TCP_WR_DATA_EN_IN;
3076 
        tcp_wr_data <= TCP_WR_DATA_IN;
3077 
        tcp_wr_data_flush <= TCP_WR_DATA_FLUSH_IN;
3078 
        tcp_tx_data_rd <= '1' when (tx_packet_state = LOAD_TX_PACKET_DATA) or (tx_packet_state = INIT_LOAD_TX_PACKET_DATA) else '0'; -- TODO or previous state = LOAD_TX_PACKET_DATA
3079 
 
3080 
        TCP_TX_FIFO : TCP_FIFO
3081 
          PORT MAP (
3082 
                 clk                            => CLK_IN,
3083 
                 din                            => tcp_wr_data,
3084 
                 wr_en                  => tcp_wr_data_en,
3085 
                 rd_en                  => tcp_tx_data_rd,
3086 
                 dout                   => tcp_tx_data,
3087 
                 full                   => open,
3088 
                 almost_full    => open,
3089 
                 empty                  => open,
3090 
                 data_count     => tcp_wr_data_count);
3091 
 
3092 
        --- Network Stats ---
3093 
 
3094 
--      process(CLK_IN)
3095 
--      begin
3096 
--              if rising_edge(CLK_IN) then
3097 
--                      clk_1hz_prev <= clk_1hz;
3098 
--                      if clk_1hz_prev = '0' and clk_1hz = '1' then
3099 
--                              rx_kbytes_sec <= rx_bytes_counter(21 downto 10);
3100 
--                      end if;
3101 
--                      if clk_1hz_prev = '0' and clk_1hz = '1' then
3102 
--                              rx_bytes_counter <= (others => '0');
3103 
--                      elsif packet_handler_state = CHECK_TCP_PSH_ACK_PACKET2 then
3104 
--                              rx_bytes_counter <= rx_bytes_counter + RESIZE(total_packet_length, 22);
3105 
--                      end if;
3106 
--              end if;
3107 
--      end process;
3108 
 
3109 
        --- DATA I/O ---
3110 
 
3111 
--      process(CLK_IN)
3112 
--      begin
3113 
--              if rising_edge(CLK_IN) then
3114 
--                      if ADDR_IN = X"00" then
3115 
--                              DATA_OUT <= "0000000" & network_interface_enabled;
3116 
--                      elsif ADDR_IN = X"01" then
3117 
--                              DATA_OUT <= mac_addr(47 downto 40);
3118 
--                      elsif ADDR_IN = X"02" then
3119 
--                              DATA_OUT <= mac_addr(39 downto 32);
3120 
--                      elsif ADDR_IN = X"03" then
3121 
--                              DATA_OUT <= mac_addr(31 downto 24);
3122 
--                      elsif ADDR_IN = X"04" then
3123 
--                              DATA_OUT <= mac_addr(23 downto 16);
3124 
--                      elsif ADDR_IN = X"05" then
3125 
--                              DATA_OUT <= mac_addr(15 downto 8);
3126 
--                      elsif ADDR_IN = X"06" then
3127 
--                              DATA_OUT <= mac_addr(7 downto 0);
3128 
--                      elsif ADDR_IN = X"07" then
3129 
--                              DATA_OUT <= "0000000" & dhcp_enable;
3130 
--                      elsif ADDR_IN = X"08" then
3131 
--                              DATA_OUT <= "000000" & static_addr_locked & dhcp_addr_locked;
3132 
--                      elsif ADDR_IN = X"09" then
3133 
--                              DATA_OUT <= ip_addr(31 downto 24);
3134 
--                      elsif ADDR_IN = X"0A" then
3135 
--                              DATA_OUT <= ip_addr(23 downto 16);
3136 
--                      elsif ADDR_IN = X"0B" then
3137 
--                              DATA_OUT <= ip_addr(15 downto 8);
3138 
--                      elsif ADDR_IN = X"0C" then
3139 
--                              DATA_OUT <= ip_addr(7 downto 0);
3140 
--                      elsif ADDR_IN = X"0D" then
3141 
--                              DATA_OUT <= cloud_ip_addr(31 downto 24);
3142 
--                      elsif ADDR_IN = X"0E" then
3143 
--                              DATA_OUT <= cloud_ip_addr(23 downto 16);
3144 
--                      elsif ADDR_IN = X"0F" then
3145 
--                              DATA_OUT <= cloud_ip_addr(15 downto 8);
3146 
--                      elsif ADDR_IN = X"10" then
3147 
--                              DATA_OUT <= cloud_ip_addr(7 downto 0);
3148 
--                      elsif ADDR_IN = X"11" then
3149 
--                              DATA_OUT <= "0000000" & tcp_connection_active;
3150 
--                      end if;
3151 
--              end if;
3152 
--      end process;
3153 
 
3154 
end Behavioral;
3155 
 

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