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/IPv4_RX.vhd
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---------------------------------------------------------------------------------- |
-- Company: |
-- Engineer: Peter Fall |
-- |
-- Create Date: 16:20:42 06/01/2011 |
-- Design Name: |
-- Module Name: IPv4_RX - Behavioral |
-- Project Name: |
-- Target Devices: |
-- Tool versions: |
-- Description: |
-- handle simple IP RX |
-- doesnt handle reassembly |
-- checks and filters for IP protocol |
-- checks and filters for IP addr |
-- Handle IPv4 protocol |
-- Dependencies: |
-- |
-- Revision: |
-- Revision 0.01 - File Created |
-- Revision 0.02 - Improved error handling |
-- Revision 0.03 - Added handling of broadcast address |
-- Additional Comments: |
-- |
---------------------------------------------------------------------------------- |
library IEEE; |
use IEEE.STD_LOGIC_1164.all; |
use IEEE.NUMERIC_STD.all; |
use work.axi.all; |
use work.ipv4_types.all; |
use work.arp_types.all; |
|
entity IPv4_RX is |
port ( |
-- IP Layer signals |
ip_rx : out ipv4_rx_type; |
ip_rx_start : out std_logic; -- indicates receipt of ip frame. |
-- system signals |
clk : in std_logic; -- same clock used to clock mac data and ip data |
reset : in std_logic; |
our_ip_address : in std_logic_vector (31 downto 0); |
rx_pkt_count : out std_logic_vector(7 downto 0); -- number of IP pkts received for us |
-- MAC layer RX signals |
mac_data_in : in std_logic_vector (7 downto 0); -- ethernet frame (from dst mac addr through to last byte of frame) |
mac_data_in_valid : in std_logic; -- indicates data_in valid on clock |
mac_data_in_last : in std_logic -- indicates last data in frame |
); |
end IPv4_RX; |
|
architecture Behavioral of IPv4_RX is |
|
type rx_state_type is (IDLE, ETH_HDR, IP_HDR, USER_DATA, WAIT_END, ERR); |
|
type rx_event_type is (NO_EVENT, DATA); |
type count_mode_type is (RST, INCR, HOLD); |
type settable_count_mode_type is (RST, INCR, SET_VAL, HOLD); |
type set_clr_type is (SET, CLR, HOLD); |
|
|
-- state variables |
signal rx_state : rx_state_type; |
signal rx_count : unsigned (15 downto 0); |
signal src_ip : std_logic_vector (31 downto 0); -- src IP captured from input |
signal dst_ip : std_logic_vector (23 downto 0); -- 1st 3 bytes of dst IP captured from input |
signal is_broadcast_reg : std_logic; |
signal protocol : std_logic_vector (7 downto 0); -- src protocol captured from input |
signal data_len : std_logic_vector (15 downto 0); -- src data length captured from input |
signal ip_rx_start_reg : std_logic; -- indicates start of user data |
signal hdr_valid_reg : std_logic; -- indicates that hdr data is valid |
signal frame_err_cnt : unsigned (7 downto 0); -- number of frame errors |
signal error_code_reg : std_logic_vector (3 downto 0); |
signal rx_pkt_counter : unsigned (7 downto 0); -- number of rx frames received for us |
|
-- rx control signals |
signal next_rx_state : rx_state_type; |
signal set_rx_state : std_logic; |
signal rx_event : rx_event_type; |
signal rx_count_mode : settable_count_mode_type; |
signal set_dst_ip3 : std_logic; |
signal set_dst_ip2 : std_logic; |
signal set_dst_ip1 : std_logic; |
signal set_ip3 : std_logic; |
signal set_ip2 : std_logic; |
signal set_ip1 : std_logic; |
signal set_ip0 : std_logic; |
signal set_protocol : std_logic; |
signal set_len_H : std_logic; |
signal set_len_L : std_logic; |
signal set_ip_rx_start : set_clr_type; |
signal set_hdr_valid : set_clr_type; |
signal set_frame_err_cnt : count_mode_type; |
signal dataval : std_logic_vector (7 downto 0); |
signal rx_count_val : unsigned (15 downto 0); |
signal set_error_code : std_logic; |
signal error_code_val : std_logic_vector (3 downto 0); |
signal set_pkt_cnt : count_mode_type; |
signal set_data_last : std_logic; |
signal dst_ip_rx : std_logic_vector (31 downto 0); |
signal set_is_broadcast : set_clr_type; |
|
|
-- IP datagram header format |
-- |
-- 0 4 8 16 19 24 31 |
-- -------------------------------------------------------------------------------------------- |
-- | Version | *Header | Service Type | Total Length including header | |
-- | (4) | Length | (ignored) | (in bytes) | |
-- -------------------------------------------------------------------------------------------- |
-- | Identification | Flags | Fragment Offset | |
-- | | | (in 32 bit words) | |
-- -------------------------------------------------------------------------------------------- |
-- | Time To Live | Protocol | Header Checksum | |
-- | (ignored) | | | |
-- -------------------------------------------------------------------------------------------- |
-- | Source IP Address | |
-- | | |
-- -------------------------------------------------------------------------------------------- |
-- | Destination IP Address | |
-- | | |
-- -------------------------------------------------------------------------------------------- |
-- | Options (if any - ignored) | Padding | |
-- | | (if needed) | |
-- -------------------------------------------------------------------------------------------- |
-- | Data | |
-- | | |
-- -------------------------------------------------------------------------------------------- |
-- | .... | |
-- | | |
-- -------------------------------------------------------------------------------------------- |
-- |
-- * - in 32 bit words |
|
begin |
|
----------------------------------------------------------------------- |
-- combinatorial process to implement FSM and determine control signals |
----------------------------------------------------------------------- |
|
rx_combinatorial : process ( |
-- input signals |
mac_data_in, mac_data_in_valid, mac_data_in_last, our_ip_address, |
-- state variables |
rx_state, rx_count, src_ip, dst_ip, protocol, data_len, ip_rx_start_reg, hdr_valid_reg, |
frame_err_cnt, error_code_reg, rx_pkt_counter, is_broadcast_reg, |
-- control signals |
next_rx_state, set_rx_state, rx_event, rx_count_mode, |
set_ip3, set_ip2, set_ip1, set_ip0, set_protocol, set_len_H, set_len_L, |
set_dst_ip3, set_dst_ip2, set_dst_ip1, |
set_ip_rx_start, set_hdr_valid, set_frame_err_cnt, dataval, rx_count_val, |
set_error_code, error_code_val, set_pkt_cnt, set_data_last, dst_ip_rx, set_is_broadcast |
) |
begin |
-- set output followers |
ip_rx_start <= ip_rx_start_reg; |
ip_rx.hdr.is_valid <= hdr_valid_reg; |
ip_rx.hdr.protocol <= protocol; |
ip_rx.hdr.data_length <= data_len; |
ip_rx.hdr.src_ip_addr <= src_ip; |
ip_rx.hdr.num_frame_errors <= std_logic_vector(frame_err_cnt); |
ip_rx.hdr.last_error_code <= error_code_reg; |
ip_rx.hdr.is_broadcast <= is_broadcast_reg; |
rx_pkt_count <= std_logic_vector(rx_pkt_counter); |
|
-- transfer data upstream if in user data phase |
if rx_state = USER_DATA then |
ip_rx.data.data_in <= mac_data_in; |
ip_rx.data.data_in_valid <= mac_data_in_valid; |
ip_rx.data.data_in_last <= set_data_last; |
else |
ip_rx.data.data_in <= (others => '0'); |
ip_rx.data.data_in_valid <= '0'; |
ip_rx.data.data_in_last <= '0'; |
end if; |
|
-- set signal defaults |
next_rx_state <= IDLE; |
set_rx_state <= '0'; |
rx_event <= NO_EVENT; |
rx_count_mode <= HOLD; |
set_ip3 <= '0'; |
set_ip2 <= '0'; |
set_ip1 <= '0'; |
set_ip0 <= '0'; |
set_dst_ip3 <= '0'; |
set_dst_ip2 <= '0'; |
set_dst_ip1 <= '0'; |
set_protocol <= '0'; |
set_len_H <= '0'; |
set_len_L <= '0'; |
set_ip_rx_start <= HOLD; |
set_hdr_valid <= HOLD; |
set_frame_err_cnt <= HOLD; |
rx_count_val <= x"0000"; |
set_error_code <= '0'; |
error_code_val <= RX_EC_NONE; |
set_pkt_cnt <= HOLD; |
dataval <= (others => '0'); |
set_data_last <= '0'; |
dst_ip_rx <= (others => '0'); |
set_is_broadcast <= HOLD; |
|
-- determine event (if any) |
if mac_data_in_valid = '1' then |
rx_event <= DATA; |
dataval <= mac_data_in; |
end if; |
|
-- RX FSM |
case rx_state is |
when IDLE => |
rx_count_mode <= RST; |
case rx_event is |
when NO_EVENT => -- (nothing to do) |
when DATA => |
rx_count_mode <= INCR; |
set_hdr_valid <= CLR; |
next_rx_state <= ETH_HDR; |
set_rx_state <= '1'; |
end case; |
|
when ETH_HDR => |
case rx_event is |
when NO_EVENT => -- (nothing to do) |
when DATA => |
if rx_count = x"000d" then |
rx_count_mode <= RST; |
next_rx_state <= IP_HDR; |
set_rx_state <= '1'; |
else |
rx_count_mode <= INCR; |
end if; |
-- handle early frame termination |
if mac_data_in_last = '1' then |
error_code_val <= RX_EC_ET_ETH; |
set_error_code <= '1'; |
set_frame_err_cnt <= INCR; |
set_ip_rx_start <= CLR; |
set_data_last <= '1'; |
next_rx_state <= IDLE; |
rx_count_mode <= RST; |
set_rx_state <= '1'; |
else |
case rx_count is |
when x"000c" => |
if mac_data_in /= x"08" then -- ignore pkts that are not type=IP |
next_rx_state <= WAIT_END; |
set_rx_state <= '1'; |
end if; |
|
when x"000d" => |
if mac_data_in /= x"00" then -- ignore pkts that are not type=IP |
next_rx_state <= WAIT_END; |
set_rx_state <= '1'; |
end if; |
|
when others => -- ignore other bytes in eth header |
end case; |
end if; |
end case; |
|
when IP_HDR => |
case rx_event is |
when NO_EVENT => -- (nothing to do) |
when DATA => |
if rx_count = x"0013" then |
rx_count_val <= x"0001"; -- start counter at 1 |
rx_count_mode <= SET_VAL; |
else |
rx_count_mode <= INCR; |
end if; |
-- handle early frame termination |
if mac_data_in_last = '1' then |
error_code_val <= RX_EC_ET_IP; |
set_error_code <= '1'; |
set_frame_err_cnt <= INCR; |
set_ip_rx_start <= CLR; |
set_data_last <= '1'; |
next_rx_state <= IDLE; |
rx_count_mode <= RST; |
set_rx_state <= '1'; |
else |
case rx_count is |
when x"0000" => |
if mac_data_in /= x"45" then -- ignore pkts that are not v4 with 5 header words |
next_rx_state <= WAIT_END; |
set_rx_state <= '1'; |
end if; |
|
when x"0002" => set_len_H <= '1'; |
when x"0003" => set_len_L <= '1'; |
|
when x"0006" => |
if (mac_data_in(7) = '1') or (mac_data_in (4 downto 0) /= "00000") then |
-- ignore pkts that require reassembly (MF=1 or frag offst /= 0) |
next_rx_state <= WAIT_END; |
set_rx_state <= '1'; |
end if; |
|
when x"0007" => |
if mac_data_in /= x"00" then -- ignore pkts that require reassembly (frag offst /= 0) |
next_rx_state <= WAIT_END; |
set_rx_state <= '1'; |
end if; |
|
when x"0009" => set_protocol <= '1'; |
|
when x"000c" => set_ip3 <= '1'; |
when x"000d" => set_ip2 <= '1'; |
when x"000e" => set_ip1 <= '1'; |
when x"000f" => set_ip0 <= '1'; |
|
when x"0010" => set_dst_ip3 <= '1'; |
if ((mac_data_in /= our_ip_address(31 downto 24)) and |
(mac_data_in /= IP_BC_ADDR(31 downto 24)))then -- ignore pkts that are not addressed to us |
next_rx_state <= WAIT_END; |
set_rx_state <= '1'; |
end if; |
when x"0011" => set_dst_ip2 <= '1'; |
if ((mac_data_in /= our_ip_address(23 downto 16)) and |
(mac_data_in /= IP_BC_ADDR(23 downto 16)))then -- ignore pkts that are not addressed to us |
next_rx_state <= WAIT_END; |
set_rx_state <= '1'; |
end if; |
when x"0012" => set_dst_ip1 <= '1'; |
if ((mac_data_in /= our_ip_address(15 downto 8)) and |
(mac_data_in /= IP_BC_ADDR(15 downto 8)))then -- ignore pkts that are not addressed to us |
next_rx_state <= WAIT_END; |
set_rx_state <= '1'; |
end if; |
|
when x"0013" => |
if ((mac_data_in /= our_ip_address(7 downto 0)) and |
(mac_data_in /= IP_BC_ADDR(7 downto 0)))then -- ignore pkts that are not addressed to us |
next_rx_state <= WAIT_END; |
set_rx_state <= '1'; |
else |
next_rx_state <= USER_DATA; |
set_pkt_cnt <= INCR; -- count another pkt |
set_rx_state <= '1'; |
set_ip_rx_start <= SET; |
end if; |
|
-- now have the dst IP addr |
dst_ip_rx <= dst_ip & mac_data_in; |
if dst_ip_rx = IP_BC_ADDR then |
set_is_broadcast <= SET; |
else |
set_is_broadcast <= CLR; |
end if; |
set_hdr_valid <= SET; -- header values are now valid, although the pkt may not be for us |
|
--if dst_ip_rx = our_ip_address or dst_ip_rx = IP_BC_ADDR then |
-- next_rx_state <= USER_DATA; |
-- set_pkt_cnt <= INCR; -- count another pkt received |
-- set_rx_state <= '1'; |
-- set_ip_rx_start <= SET; |
--else |
-- next_rx_state <= WAIT_END; |
-- set_rx_state <= '1'; |
--end if; |
|
when others => -- ignore other bytes in ip header |
end case; |
end if; |
end case; |
|
when USER_DATA => |
case rx_event is |
when NO_EVENT => -- (nothing to do) |
when DATA => |
-- note: data gets transfered upstream as part of "output followers" processing |
if rx_count = unsigned(data_len) then |
set_ip_rx_start <= CLR; |
rx_count_mode <= RST; |
set_data_last <= '1'; |
if mac_data_in_last = '1' then |
next_rx_state <= IDLE; |
rx_count_mode <= RST; |
set_ip_rx_start <= CLR; |
else |
next_rx_state <= WAIT_END; |
end if; |
set_rx_state <= '1'; |
else |
rx_count_mode <= INCR; |
-- check for early frame termination |
if mac_data_in_last = '1' then |
error_code_val <= RX_EC_ET_USER; |
set_error_code <= '1'; |
set_frame_err_cnt <= INCR; |
set_ip_rx_start <= CLR; |
next_rx_state <= IDLE; |
rx_count_mode <= RST; |
set_rx_state <= '1'; |
end if; |
end if; |
end case; |
|
when ERR => |
set_frame_err_cnt <= INCR; |
set_ip_rx_start <= CLR; |
if mac_data_in_last = '0' then |
set_data_last <= '1'; |
next_rx_state <= WAIT_END; |
set_rx_state <= '1'; |
else |
next_rx_state <= IDLE; |
rx_count_mode <= RST; |
set_rx_state <= '1'; |
end if; |
|
|
when WAIT_END => |
case rx_event is |
when NO_EVENT => -- (nothing to do) |
when DATA => |
if mac_data_in_last = '1' then |
set_data_last <= '1'; |
next_rx_state <= IDLE; |
rx_count_mode <= RST; |
set_rx_state <= '1'; |
set_ip_rx_start <= CLR; |
end if; |
end case; |
|
end case; |
|
end process; |
|
|
----------------------------------------------------------------------------- |
-- sequential process to action control signals and change states and outputs |
----------------------------------------------------------------------------- |
|
rx_sequential : process (clk)--, reset) |
begin |
if rising_edge(clk) then |
if reset = '1' then |
-- reset state variables |
rx_state <= IDLE; |
rx_count <= x"0000"; |
src_ip <= (others => '0'); |
dst_ip <= (others => '0'); |
protocol <= (others => '0'); |
data_len <= (others => '0'); |
ip_rx_start_reg <= '0'; |
hdr_valid_reg <= '0'; |
is_broadcast_reg <= '0'; |
frame_err_cnt <= (others => '0'); |
error_code_reg <= RX_EC_NONE; |
rx_pkt_counter <= x"00"; |
|
else |
-- Next rx_state processing |
if set_rx_state = '1' then |
rx_state <= next_rx_state; |
else |
rx_state <= rx_state; |
end if; |
|
-- rx_count processing |
case rx_count_mode is |
when RST => rx_count <= x"0000"; |
when INCR => rx_count <= rx_count + 1; |
when SET_VAL => rx_count <= rx_count_val; |
when HOLD => rx_count <= rx_count; |
end case; |
|
-- frame error count processing |
case set_frame_err_cnt is |
when RST => frame_err_cnt <= x"00"; |
when INCR => frame_err_cnt <= frame_err_cnt + 1; |
when HOLD => frame_err_cnt <= frame_err_cnt; |
end case; |
|
-- ip pkt processing |
case set_pkt_cnt is |
when RST => rx_pkt_counter <= x"00"; |
when INCR => rx_pkt_counter <= rx_pkt_counter + 1; |
when HOLD => rx_pkt_counter <= rx_pkt_counter; |
end case; |
|
-- source ip capture |
if (set_ip3 = '1') then src_ip(31 downto 24) <= dataval; end if; |
if (set_ip2 = '1') then src_ip(23 downto 16) <= dataval; end if; |
if (set_ip1 = '1') then src_ip(15 downto 8) <= dataval; end if; |
if (set_ip0 = '1') then src_ip(7 downto 0) <= dataval; end if; |
|
-- dst ip capture |
if (set_dst_ip3 = '1') then dst_ip(23 downto 16) <= dataval; end if; |
if (set_dst_ip2 = '1') then dst_ip(15 downto 8) <= dataval; end if; |
if (set_dst_ip1 = '1') then dst_ip(7 downto 0) <= dataval; end if; |
|
if (set_protocol = '1') then |
protocol <= dataval; |
else |
protocol <= protocol; |
end if; |
|
if (set_len_H = '1') then |
data_len (15 downto 8) <= dataval; |
data_len (7 downto 0) <= x"00"; |
elsif (set_len_L = '1') then |
-- compute data length, taking into account that we need to subtract the header length |
data_len <= std_logic_vector(unsigned(data_len(15 downto 8) & dataval) - 20); |
else |
data_len <= data_len; |
end if; |
|
case set_ip_rx_start is |
when SET => ip_rx_start_reg <= '1'; |
when CLR => ip_rx_start_reg <= '0'; |
when HOLD => ip_rx_start_reg <= ip_rx_start_reg; |
end case; |
|
case set_is_broadcast is |
when SET => is_broadcast_reg <= '1'; |
when CLR => is_broadcast_reg <= '0'; |
when HOLD => is_broadcast_reg <= is_broadcast_reg; |
end case; |
|
case set_hdr_valid is |
when SET => hdr_valid_reg <= '1'; |
when CLR => hdr_valid_reg <= '0'; |
when HOLD => hdr_valid_reg <= hdr_valid_reg; |
end case; |
|
-- set error code |
if set_error_code = '1' then |
error_code_reg <= error_code_val; |
else |
error_code_reg <= error_code_reg; |
end if; |
end if; |
end if; |
end process; |
|
end Behavioral; |
|
---------------------------------------------------------------------------------- |
-- Company: |
-- Engineer: Peter Fall |
-- |
-- Create Date: 16:20:42 06/01/2011 |
-- Design Name: |
-- Module Name: IPv4_RX - Behavioral |
-- Project Name: |
-- Target Devices: |
-- Tool versions: |
-- Description: |
-- handle simple IP RX |
-- doesnt handle reassembly |
-- checks and filters for IP protocol |
-- checks and filters for IP addr |
-- Handle IPv4 protocol |
-- Dependencies: |
-- |
-- Revision: |
-- Revision 0.01 - File Created |
-- Revision 0.02 - Improved error handling |
-- Revision 0.03 - Added handling of broadcast address |
-- Additional Comments: |
-- |
---------------------------------------------------------------------------------- |
library IEEE; |
use IEEE.STD_LOGIC_1164.all; |
use IEEE.NUMERIC_STD.all; |
use work.axi.all; |
use work.ipv4_types.all; |
use work.arp_types.all; |
|
entity IPv4_RX is |
port ( |
-- IP Layer signals |
ip_rx : out ipv4_rx_type; |
ip_rx_start : out std_logic; -- indicates receipt of ip frame. |
-- system signals |
clk : in std_logic; -- same clock used to clock mac data and ip data |
reset : in std_logic; |
our_ip_address : in std_logic_vector (31 downto 0); |
rx_pkt_count : out std_logic_vector(7 downto 0); -- number of IP pkts received for us |
-- MAC layer RX signals |
mac_data_in : in std_logic_vector (7 downto 0); -- ethernet frame (from dst mac addr through to last byte of frame) |
mac_data_in_valid : in std_logic; -- indicates data_in valid on clock |
mac_data_in_last : in std_logic -- indicates last data in frame |
); |
end IPv4_RX; |
|
architecture Behavioral of IPv4_RX is |
|
type rx_state_type is (IDLE, ETH_HDR, IP_HDR, USER_DATA, WAIT_END, ERR); |
|
type rx_event_type is (NO_EVENT, DATA); |
type count_mode_type is (RST, INCR, HOLD); |
type settable_count_mode_type is (RST, INCR, SET_VAL, HOLD); |
type set_clr_type is (SET, CLR, HOLD); |
|
|
-- state variables |
signal rx_state : rx_state_type; |
signal rx_count : unsigned (15 downto 0); |
signal src_ip : std_logic_vector (31 downto 0); -- src IP captured from input |
signal dst_ip : std_logic_vector (23 downto 0); -- 1st 3 bytes of dst IP captured from input |
signal is_broadcast_reg : std_logic; |
signal protocol : std_logic_vector (7 downto 0); -- src protocol captured from input |
signal data_len : std_logic_vector (15 downto 0); -- src data length captured from input |
signal ip_rx_start_reg : std_logic; -- indicates start of user data |
signal hdr_valid_reg : std_logic; -- indicates that hdr data is valid |
signal frame_err_cnt : unsigned (7 downto 0); -- number of frame errors |
signal error_code_reg : std_logic_vector (3 downto 0); |
signal rx_pkt_counter : unsigned (7 downto 0); -- number of rx frames received for us |
|
-- rx control signals |
signal next_rx_state : rx_state_type; |
signal set_rx_state : std_logic; |
signal rx_event : rx_event_type; |
signal rx_count_mode : settable_count_mode_type; |
signal set_dst_ip3 : std_logic; |
signal set_dst_ip2 : std_logic; |
signal set_dst_ip1 : std_logic; |
signal set_ip3 : std_logic; |
signal set_ip2 : std_logic; |
signal set_ip1 : std_logic; |
signal set_ip0 : std_logic; |
signal set_protocol : std_logic; |
signal set_len_H : std_logic; |
signal set_len_L : std_logic; |
signal set_ip_rx_start : set_clr_type; |
signal set_hdr_valid : set_clr_type; |
signal set_frame_err_cnt : count_mode_type; |
signal dataval : std_logic_vector (7 downto 0); |
signal rx_count_val : unsigned (15 downto 0); |
signal set_error_code : std_logic; |
signal error_code_val : std_logic_vector (3 downto 0); |
signal set_pkt_cnt : count_mode_type; |
signal set_data_last : std_logic; |
signal dst_ip_rx : std_logic_vector (31 downto 0); |
signal set_is_broadcast : set_clr_type; |
|
|
-- IP datagram header format |
-- |
-- 0 4 8 16 19 24 31 |
-- -------------------------------------------------------------------------------------------- |
-- | Version | *Header | Service Type | Total Length including header | |
-- | (4) | Length | (ignored) | (in bytes) | |
-- -------------------------------------------------------------------------------------------- |
-- | Identification | Flags | Fragment Offset | |
-- | | | (in 32 bit words) | |
-- -------------------------------------------------------------------------------------------- |
-- | Time To Live | Protocol | Header Checksum | |
-- | (ignored) | | | |
-- -------------------------------------------------------------------------------------------- |
-- | Source IP Address | |
-- | | |
-- -------------------------------------------------------------------------------------------- |
-- | Destination IP Address | |
-- | | |
-- -------------------------------------------------------------------------------------------- |
-- | Options (if any - ignored) | Padding | |
-- | | (if needed) | |
-- -------------------------------------------------------------------------------------------- |
-- | Data | |
-- | | |
-- -------------------------------------------------------------------------------------------- |
-- | .... | |
-- | | |
-- -------------------------------------------------------------------------------------------- |
-- |
-- * - in 32 bit words |
|
begin |
|
----------------------------------------------------------------------- |
-- combinatorial process to implement FSM and determine control signals |
----------------------------------------------------------------------- |
|
rx_combinatorial : process ( |
-- input signals |
mac_data_in, mac_data_in_valid, mac_data_in_last, our_ip_address, |
-- state variables |
rx_state, rx_count, src_ip, dst_ip, protocol, data_len, ip_rx_start_reg, hdr_valid_reg, |
frame_err_cnt, error_code_reg, rx_pkt_counter, is_broadcast_reg, |
-- control signals |
next_rx_state, set_rx_state, rx_event, rx_count_mode, |
set_ip3, set_ip2, set_ip1, set_ip0, set_protocol, set_len_H, set_len_L, |
set_dst_ip3, set_dst_ip2, set_dst_ip1, |
set_ip_rx_start, set_hdr_valid, set_frame_err_cnt, dataval, rx_count_val, |
set_error_code, error_code_val, set_pkt_cnt, set_data_last, dst_ip_rx, set_is_broadcast |
) |
begin |
-- set output followers |
ip_rx_start <= ip_rx_start_reg; |
ip_rx.hdr.is_valid <= hdr_valid_reg; |
ip_rx.hdr.protocol <= protocol; |
ip_rx.hdr.data_length <= data_len; |
ip_rx.hdr.src_ip_addr <= src_ip; |
ip_rx.hdr.num_frame_errors <= std_logic_vector(frame_err_cnt); |
ip_rx.hdr.last_error_code <= error_code_reg; |
ip_rx.hdr.is_broadcast <= is_broadcast_reg; |
rx_pkt_count <= std_logic_vector(rx_pkt_counter); |
|
-- transfer data upstream if in user data phase |
if rx_state = USER_DATA then |
ip_rx.data.data_in <= mac_data_in; |
ip_rx.data.data_in_valid <= mac_data_in_valid; |
ip_rx.data.data_in_last <= set_data_last; |
else |
ip_rx.data.data_in <= (others => '0'); |
ip_rx.data.data_in_valid <= '0'; |
ip_rx.data.data_in_last <= '0'; |
end if; |
|
-- set signal defaults |
next_rx_state <= IDLE; |
set_rx_state <= '0'; |
rx_event <= NO_EVENT; |
rx_count_mode <= HOLD; |
set_ip3 <= '0'; |
set_ip2 <= '0'; |
set_ip1 <= '0'; |
set_ip0 <= '0'; |
set_dst_ip3 <= '0'; |
set_dst_ip2 <= '0'; |
set_dst_ip1 <= '0'; |
set_protocol <= '0'; |
set_len_H <= '0'; |
set_len_L <= '0'; |
set_ip_rx_start <= HOLD; |
set_hdr_valid <= HOLD; |
set_frame_err_cnt <= HOLD; |
rx_count_val <= x"0000"; |
set_error_code <= '0'; |
error_code_val <= RX_EC_NONE; |
set_pkt_cnt <= HOLD; |
dataval <= (others => '0'); |
set_data_last <= '0'; |
dst_ip_rx <= (others => '0'); |
set_is_broadcast <= HOLD; |
|
-- determine event (if any) |
if mac_data_in_valid = '1' then |
rx_event <= DATA; |
dataval <= mac_data_in; |
end if; |
|
-- RX FSM |
case rx_state is |
when IDLE => |
rx_count_mode <= RST; |
case rx_event is |
when NO_EVENT => -- (nothing to do) |
when DATA => |
rx_count_mode <= INCR; |
set_hdr_valid <= CLR; |
next_rx_state <= ETH_HDR; |
set_rx_state <= '1'; |
end case; |
|
when ETH_HDR => |
case rx_event is |
when NO_EVENT => -- (nothing to do) |
when DATA => |
if rx_count = x"000d" then |
rx_count_mode <= RST; |
next_rx_state <= IP_HDR; |
set_rx_state <= '1'; |
else |
rx_count_mode <= INCR; |
end if; |
-- handle early frame termination |
if mac_data_in_last = '1' then |
error_code_val <= RX_EC_ET_ETH; |
set_error_code <= '1'; |
set_frame_err_cnt <= INCR; |
set_ip_rx_start <= CLR; |
set_data_last <= '1'; |
next_rx_state <= IDLE; |
set_rx_state <= '1'; |
else |
case rx_count is |
when x"000c" => |
if mac_data_in /= x"08" then -- ignore pkts that are not type=IP |
next_rx_state <= WAIT_END; |
set_rx_state <= '1'; |
end if; |
|
when x"000d" => |
if mac_data_in /= x"00" then -- ignore pkts that are not type=IP |
next_rx_state <= WAIT_END; |
set_rx_state <= '1'; |
end if; |
|
when others => -- ignore other bytes in eth header |
end case; |
end if; |
end case; |
|
when IP_HDR => |
case rx_event is |
when NO_EVENT => -- (nothing to do) |
when DATA => |
if rx_count = x"0013" then |
rx_count_val <= x"0001"; -- start counter at 1 |
rx_count_mode <= SET_VAL; |
else |
rx_count_mode <= INCR; |
end if; |
-- handle early frame termination |
if mac_data_in_last = '1' then |
error_code_val <= RX_EC_ET_IP; |
set_error_code <= '1'; |
set_frame_err_cnt <= INCR; |
set_ip_rx_start <= CLR; |
set_data_last <= '1'; |
next_rx_state <= IDLE; |
set_rx_state <= '1'; |
else |
case rx_count is |
when x"0000" => |
if mac_data_in /= x"45" then -- ignore pkts that are not v4 with 5 header words |
next_rx_state <= WAIT_END; |
set_rx_state <= '1'; |
end if; |
|
when x"0002" => set_len_H <= '1'; |
when x"0003" => set_len_L <= '1'; |
|
when x"0006" => |
if (mac_data_in(7) = '1') or (mac_data_in (4 downto 0) /= "00000") then |
-- ignore pkts that require reassembly (MF=1 or frag offst /= 0) |
next_rx_state <= WAIT_END; |
set_rx_state <= '1'; |
end if; |
|
when x"0007" => |
if mac_data_in /= x"00" then -- ignore pkts that require reassembly (frag offst /= 0) |
next_rx_state <= WAIT_END; |
set_rx_state <= '1'; |
end if; |
|
when x"0009" => set_protocol <= '1'; |
|
when x"000c" => set_ip3 <= '1'; |
when x"000d" => set_ip2 <= '1'; |
when x"000e" => set_ip1 <= '1'; |
when x"000f" => set_ip0 <= '1'; |
|
when x"0010" => set_dst_ip3 <= '1'; |
if ((mac_data_in /= our_ip_address(31 downto 24)) and |
(mac_data_in /= IP_BC_ADDR(31 downto 24)))then -- ignore pkts that are not addressed to us |
next_rx_state <= WAIT_END; |
set_rx_state <= '1'; |
end if; |
when x"0011" => set_dst_ip2 <= '1'; |
if ((mac_data_in /= our_ip_address(23 downto 16)) and |
(mac_data_in /= IP_BC_ADDR(23 downto 16)))then -- ignore pkts that are not addressed to us |
next_rx_state <= WAIT_END; |
set_rx_state <= '1'; |
end if; |
when x"0012" => set_dst_ip1 <= '1'; |
if ((mac_data_in /= our_ip_address(15 downto 8)) and |
(mac_data_in /= IP_BC_ADDR(15 downto 8)))then -- ignore pkts that are not addressed to us |
next_rx_state <= WAIT_END; |
set_rx_state <= '1'; |
end if; |
|
when x"0013" => |
if ((mac_data_in /= our_ip_address(7 downto 0)) and |
(mac_data_in /= IP_BC_ADDR(7 downto 0)))then -- ignore pkts that are not addressed to us |
next_rx_state <= WAIT_END; |
set_rx_state <= '1'; |
else |
next_rx_state <= USER_DATA; |
set_pkt_cnt <= INCR; -- count another pkt |
set_rx_state <= '1'; |
set_ip_rx_start <= SET; |
end if; |
|
-- now have the dst IP addr |
dst_ip_rx <= dst_ip & mac_data_in; |
if dst_ip_rx = IP_BC_ADDR then |
set_is_broadcast <= SET; |
else |
set_is_broadcast <= CLR; |
end if; |
set_hdr_valid <= SET; -- header values are now valid, although the pkt may not be for us |
|
--if dst_ip_rx = our_ip_address or dst_ip_rx = IP_BC_ADDR then |
-- next_rx_state <= USER_DATA; |
-- set_pkt_cnt <= INCR; -- count another pkt received |
-- set_rx_state <= '1'; |
-- set_ip_rx_start <= SET; |
--else |
-- next_rx_state <= WAIT_END; |
-- set_rx_state <= '1'; |
--end if; |
|
when others => -- ignore other bytes in ip header |
end case; |
end if; |
end case; |
|
when USER_DATA => |
case rx_event is |
when NO_EVENT => -- (nothing to do) |
when DATA => |
-- note: data gets transfered upstream as part of "output followers" processing |
if rx_count = unsigned(data_len) then |
set_ip_rx_start <= CLR; |
rx_count_mode <= RST; |
set_data_last <= '1'; |
if mac_data_in_last = '1' then |
next_rx_state <= IDLE; |
set_ip_rx_start <= CLR; |
else |
next_rx_state <= WAIT_END; |
end if; |
set_rx_state <= '1'; |
else |
rx_count_mode <= INCR; |
-- check for early frame termination |
if mac_data_in_last = '1' then |
error_code_val <= RX_EC_ET_USER; |
set_error_code <= '1'; |
set_frame_err_cnt <= INCR; |
set_ip_rx_start <= CLR; |
next_rx_state <= IDLE; |
set_rx_state <= '1'; |
end if; |
end if; |
end case; |
|
when ERR => |
set_frame_err_cnt <= INCR; |
set_ip_rx_start <= CLR; |
if mac_data_in_last = '0' then |
set_data_last <= '1'; |
next_rx_state <= WAIT_END; |
set_rx_state <= '1'; |
else |
next_rx_state <= IDLE; |
set_rx_state <= '1'; |
end if; |
|
|
when WAIT_END => |
case rx_event is |
when NO_EVENT => -- (nothing to do) |
when DATA => |
if mac_data_in_last = '1' then |
set_data_last <= '1'; |
next_rx_state <= IDLE; |
set_rx_state <= '1'; |
set_ip_rx_start <= CLR; |
end if; |
end case; |
|
end case; |
|
end process; |
|
|
----------------------------------------------------------------------------- |
-- sequential process to action control signals and change states and outputs |
----------------------------------------------------------------------------- |
|
rx_sequential : process (clk)--, reset) |
begin |
if rising_edge(clk) then |
if reset = '1' then |
-- reset state variables |
rx_state <= IDLE; |
rx_count <= x"0000"; |
src_ip <= (others => '0'); |
dst_ip <= (others => '0'); |
protocol <= (others => '0'); |
data_len <= (others => '0'); |
ip_rx_start_reg <= '0'; |
hdr_valid_reg <= '0'; |
is_broadcast_reg <= '0'; |
frame_err_cnt <= (others => '0'); |
error_code_reg <= RX_EC_NONE; |
rx_pkt_counter <= x"00"; |
|
else |
-- Next rx_state processing |
if set_rx_state = '1' then |
rx_state <= next_rx_state; |
else |
rx_state <= rx_state; |
end if; |
|
-- rx_count processing |
case rx_count_mode is |
when RST => rx_count <= x"0000"; |
when INCR => rx_count <= rx_count + 1; |
when SET_VAL => rx_count <= rx_count_val; |
when HOLD => rx_count <= rx_count; |
end case; |
|
-- frame error count processing |
case set_frame_err_cnt is |
when RST => frame_err_cnt <= x"00"; |
when INCR => frame_err_cnt <= frame_err_cnt + 1; |
when HOLD => frame_err_cnt <= frame_err_cnt; |
end case; |
|
-- ip pkt processing |
case set_pkt_cnt is |
when RST => rx_pkt_counter <= x"00"; |
when INCR => rx_pkt_counter <= rx_pkt_counter + 1; |
when HOLD => rx_pkt_counter <= rx_pkt_counter; |
end case; |
|
-- source ip capture |
if (set_ip3 = '1') then src_ip(31 downto 24) <= dataval; end if; |
if (set_ip2 = '1') then src_ip(23 downto 16) <= dataval; end if; |
if (set_ip1 = '1') then src_ip(15 downto 8) <= dataval; end if; |
if (set_ip0 = '1') then src_ip(7 downto 0) <= dataval; end if; |
|
-- dst ip capture |
if (set_dst_ip3 = '1') then dst_ip(23 downto 16) <= dataval; end if; |
if (set_dst_ip2 = '1') then dst_ip(15 downto 8) <= dataval; end if; |
if (set_dst_ip1 = '1') then dst_ip(7 downto 0) <= dataval; end if; |
|
if (set_protocol = '1') then |
protocol <= dataval; |
else |
protocol <= protocol; |
end if; |
|
if (set_len_H = '1') then |
data_len (15 downto 8) <= dataval; |
data_len (7 downto 0) <= x"00"; |
elsif (set_len_L = '1') then |
-- compute data length, taking into account that we need to subtract the header length |
data_len <= std_logic_vector(unsigned(data_len(15 downto 8) & dataval) - 20); |
else |
data_len <= data_len; |
end if; |
|
case set_ip_rx_start is |
when SET => ip_rx_start_reg <= '1'; |
when CLR => ip_rx_start_reg <= '0'; |
when HOLD => ip_rx_start_reg <= ip_rx_start_reg; |
end case; |
|
case set_is_broadcast is |
when SET => is_broadcast_reg <= '1'; |
when CLR => is_broadcast_reg <= '0'; |
when HOLD => is_broadcast_reg <= is_broadcast_reg; |
end case; |
|
case set_hdr_valid is |
when SET => hdr_valid_reg <= '1'; |
when CLR => hdr_valid_reg <= '0'; |
when HOLD => hdr_valid_reg <= hdr_valid_reg; |
end case; |
|
-- set error code |
if set_error_code = '1' then |
error_code_reg <= error_code_val; |
else |
error_code_reg <= error_code_reg; |
end if; |
end if; |
end if; |
end process; |
|
end Behavioral; |
|