----------------------------------------------------------------------------------
|
----------------------------------------------------------------------------------
|
-- Company:
|
-- Company:
|
-- Engineer: Peter Fall
|
-- Engineer: Peter Fall
|
--
|
--
|
-- Create Date: 12:00:04 05/31/2011
|
-- Create Date: 12:00:04 05/31/2011
|
-- Design Name:
|
-- Design Name:
|
-- Module Name: arp - Behavioral
|
-- Module Name: arp - Behavioral
|
-- Project Name:
|
-- Project Name:
|
-- Target Devices:
|
-- Target Devices:
|
-- Tool versions:
|
-- Tool versions:
|
-- Description:
|
-- Description:
|
-- handle simple IP lookup in cache
|
-- handle simple IP lookup in cache
|
-- request cache fill through ARP protocol if required
|
-- request cache fill through ARP protocol if required
|
-- cache is simple 1 deep
|
-- cache is simple 1 deep
|
-- Handle ARP protocol
|
-- Handle ARP protocol
|
-- Respond to ARP requests and replies
|
-- Respond to ARP requests and replies
|
-- Ignore pkts that are not ARP
|
-- Ignore pkts that are not ARP
|
-- Ignore pkts that are not addressed to us
|
-- Ignore pkts that are not addressed to us
|
--
|
--
|
-- Dependencies:
|
-- Dependencies:
|
--
|
--
|
-- Revision:
|
-- Revision:
|
-- Revision 0.01 - File Created
|
-- Revision 0.01 - File Created
|
-- Revision 0.02 - Added req for mac tx and wait for grant
|
-- Revision 0.02 - Added req for mac tx and wait for grant
|
-- Revision 0.03 - Added data_out_first
|
-- Revision 0.03 - Added data_out_first
|
-- Revision 0.04 - Added arp response timeout
|
-- Revision 0.04 - Added arp response timeout
|
-- Revision 0.05 - Added arp cache reset control
|
-- Revision 0.05 - Added arp cache reset control
|
-- Additional Comments:
|
-- Additional Comments:
|
--
|
--
|
----------------------------------------------------------------------------------
|
----------------------------------------------------------------------------------
|
library IEEE;
|
library IEEE;
|
use IEEE.STD_LOGIC_1164.ALL;
|
use IEEE.STD_LOGIC_1164.ALL;
|
use IEEE.NUMERIC_STD.ALL;
|
use IEEE.NUMERIC_STD.ALL;
|
use work.arp_types.all;
|
use work.arp_types.all;
|
|
|
entity arp is
|
entity arp is
|
generic (
|
generic (
|
CLOCK_FREQ : integer := 125000000; -- freq of data_in_clk -- needed to timout cntr
|
CLOCK_FREQ : integer := 125000000; -- freq of data_in_clk -- needed to timout cntr
|
ARP_TIMEOUT : integer := 60 -- ARP response timeout (s)
|
ARP_TIMEOUT : integer := 60; -- ARP response timeout (s)
|
|
ARP_MAX_PKT_TMO : integer := 1; -- (added for compatibility with arpv2. this value not used in this impl)
|
|
MAX_ARP_ENTRIES : integer := 1 -- (added for compatibility with arpv2. this value not used in this impl)
|
);
|
);
|
Port (
|
Port (
|
-- lookup request signals
|
-- lookup request signals
|
arp_req_req : in arp_req_req_type;
|
arp_req_req : in arp_req_req_type;
|
arp_req_rslt : out arp_req_rslt_type;
|
arp_req_rslt : out arp_req_rslt_type;
|
-- MAC layer RX signals
|
-- MAC layer RX signals
|
data_in_clk : in STD_LOGIC;
|
data_in_clk : in STD_LOGIC;
|
reset : in STD_LOGIC;
|
reset : in STD_LOGIC;
|
data_in : in STD_LOGIC_VECTOR (7 downto 0); -- ethernet frame (from dst mac addr through to last byte of frame)
|
data_in : in STD_LOGIC_VECTOR (7 downto 0); -- ethernet frame (from dst mac addr through to last byte of frame)
|
data_in_valid : in STD_LOGIC; -- indicates data_in valid on clock
|
data_in_valid : in STD_LOGIC; -- indicates data_in valid on clock
|
data_in_last : in STD_LOGIC; -- indicates last data in frame
|
data_in_last : in STD_LOGIC; -- indicates last data in frame
|
-- MAC layer TX signals
|
-- MAC layer TX signals
|
mac_tx_req : out std_logic; -- indicates that ip wants access to channel (stays up for as long as tx)
|
mac_tx_req : out std_logic; -- indicates that ip wants access to channel (stays up for as long as tx)
|
mac_tx_granted : in std_logic; -- indicates that access to channel has been granted
|
mac_tx_granted : in std_logic; -- indicates that access to channel has been granted
|
data_out_clk : in std_logic;
|
data_out_clk : in std_logic;
|
data_out_ready : in std_logic; -- indicates system ready to consume data
|
data_out_ready : in std_logic; -- indicates system ready to consume data
|
data_out_valid : out std_logic; -- indicates data out is valid
|
data_out_valid : out std_logic; -- indicates data out is valid
|
data_out_first : out std_logic; -- with data out valid indicates the first byte of a frame
|
data_out_first : out std_logic; -- with data out valid indicates the first byte of a frame
|
data_out_last : out std_logic; -- with data out valid indicates the last byte of a frame
|
data_out_last : out std_logic; -- with data out valid indicates the last byte of a frame
|
data_out : out std_logic_vector (7 downto 0); -- ethernet frame (from dst mac addr through to last byte of frame)
|
data_out : out std_logic_vector (7 downto 0); -- ethernet frame (from dst mac addr through to last byte of frame)
|
-- system signals
|
-- system signals
|
our_mac_address : in STD_LOGIC_VECTOR (47 downto 0);
|
our_mac_address : in STD_LOGIC_VECTOR (47 downto 0);
|
our_ip_address : in STD_LOGIC_VECTOR (31 downto 0);
|
our_ip_address : in STD_LOGIC_VECTOR (31 downto 0);
|
control : in arp_control_type;
|
control : in arp_control_type;
|
req_count : out STD_LOGIC_VECTOR(7 downto 0) -- count of arp pkts received
|
req_count : out STD_LOGIC_VECTOR(7 downto 0) -- count of arp pkts received
|
);
|
);
|
end arp;
|
end arp;
|
|
|
architecture Behavioral of arp is
|
architecture Behavioral of arp is
|
|
|
type req_state_type is (IDLE,LOOKUP,REQUEST,WAIT_REPLY,PAUSE1,PAUSE2,PAUSE3);
|
type req_state_type is (IDLE,LOOKUP,REQUEST,WAIT_REPLY,PAUSE1,PAUSE2,PAUSE3);
|
type rx_state_type is (IDLE,PARSE,PROCESS_ARP,WAIT_END);
|
type rx_state_type is (IDLE,PARSE,PROCESS_ARP,WAIT_END);
|
type rx_event_type is (NO_EVENT,DATA);
|
type rx_event_type is (NO_EVENT,DATA);
|
type count_mode_type is (RST,INCR,HOLD);
|
type count_mode_type is (RST,INCR,HOLD);
|
type arp_oper_type is (NOP,REQUEST,REPLY);
|
type arp_oper_type is (NOP,REQUEST,REPLY);
|
type set_clr_type is (SET, CLR, HOLD);
|
type set_clr_type is (SET, CLR, HOLD);
|
|
|
type tx_state_type is (IDLE,WAIT_MAC,SEND);
|
type tx_state_type is (IDLE,WAIT_MAC,SEND);
|
|
|
|
|
type arp_entry_type is record
|
type arp_entry_type is record
|
ip : std_logic_vector (31 downto 0);
|
ip : std_logic_vector (31 downto 0);
|
mac : std_logic_vector (47 downto 0);
|
mac : std_logic_vector (47 downto 0);
|
is_valid : std_logic;
|
is_valid : std_logic;
|
reply_required : std_logic;
|
reply_required : std_logic;
|
end record;
|
end record;
|
|
|
-- state variables
|
-- state variables
|
signal req_state : req_state_type;
|
signal req_state : req_state_type;
|
signal req_ip_addr : std_logic_vector (31 downto 0); -- IP address to lookup
|
signal req_ip_addr : std_logic_vector (31 downto 0); -- IP address to lookup
|
signal mac_addr_found : STD_LOGIC_VECTOR (47 downto 0); -- mac address found
|
signal mac_addr_found : STD_LOGIC_VECTOR (47 downto 0); -- mac address found
|
signal mac_addr_valid_reg: std_logic;
|
signal mac_addr_valid_reg: std_logic;
|
signal send_request_needed : std_logic;
|
signal send_request_needed : std_logic;
|
signal tx_mac_chn_reqd : std_logic;
|
signal tx_mac_chn_reqd : std_logic;
|
signal freq_scaler : unsigned (31 downto 0); -- scales data_in_clk downto 1Hz
|
signal freq_scaler : unsigned (31 downto 0); -- scales data_in_clk downto 1Hz
|
signal timer : unsigned (7 downto 0); -- counts seconds timeout
|
signal timer : unsigned (7 downto 0); -- counts seconds timeout
|
signal timeout_reg : std_logic;
|
signal timeout_reg : std_logic;
|
|
|
signal rx_state : rx_state_type;
|
signal rx_state : rx_state_type;
|
signal rx_count : unsigned (7 downto 0);
|
signal rx_count : unsigned (7 downto 0);
|
signal arp_operation : arp_oper_type;
|
signal arp_operation : arp_oper_type;
|
signal arp_req_count : unsigned (7 downto 0);
|
signal arp_req_count : unsigned (7 downto 0);
|
signal arp_entry : arp_entry_type; -- arp entry store
|
signal arp_entry : arp_entry_type; -- arp entry store
|
signal new_arp_entry : arp_entry_type;
|
signal new_arp_entry : arp_entry_type;
|
signal tx_state : tx_state_type;
|
signal tx_state : tx_state_type;
|
signal tx_count : unsigned (7 downto 0);
|
signal tx_count : unsigned (7 downto 0);
|
|
|
-- FIXME - remove these debug state signals
|
-- FIXME - remove these debug state signals
|
signal arp_err_data : std_logic_vector (7 downto 0);
|
signal arp_err_data : std_logic_vector (7 downto 0);
|
signal set_err_data : std_logic;
|
signal set_err_data : std_logic;
|
|
|
attribute keep : string;
|
attribute keep : string;
|
attribute keep of arp_err_data : signal is "true";
|
attribute keep of arp_err_data : signal is "true";
|
|
|
-- requester control signals
|
-- requester control signals
|
signal next_req_state : req_state_type;
|
signal next_req_state : req_state_type;
|
signal set_req_state : std_logic;
|
signal set_req_state : std_logic;
|
signal set_req_ip : std_logic;
|
signal set_req_ip : std_logic;
|
signal set_mac_addr : std_logic;
|
signal set_mac_addr : std_logic;
|
signal set_mac_addr_invalid : std_logic;
|
signal set_mac_addr_invalid : std_logic;
|
signal set_send_req : std_logic;
|
signal set_send_req : std_logic;
|
signal clear_send_req : std_logic;
|
signal clear_send_req : std_logic;
|
signal set_timer : count_mode_type; -- timer reset, count, hold control
|
signal set_timer : count_mode_type; -- timer reset, count, hold control
|
signal timer_enable : std_logic; -- enable the timer counting
|
signal timer_enable : std_logic; -- enable the timer counting
|
signal set_timeout : set_clr_type; -- control the timeout register
|
signal set_timeout : set_clr_type; -- control the timeout register
|
|
|
|
|
-- rx control signals
|
-- rx control signals
|
signal next_rx_state : rx_state_type;
|
signal next_rx_state : rx_state_type;
|
signal set_rx_state : std_logic;
|
signal set_rx_state : std_logic;
|
signal rx_event : rx_event_type;
|
signal rx_event : rx_event_type;
|
signal rx_count_mode : count_mode_type;
|
signal rx_count_mode : count_mode_type;
|
signal set_arp_oper : std_logic;
|
signal set_arp_oper : std_logic;
|
signal arp_oper_set_val : arp_oper_type;
|
signal arp_oper_set_val : arp_oper_type;
|
signal dataval : std_logic_vector (7 downto 0);
|
signal dataval : std_logic_vector (7 downto 0);
|
signal set_arp_entry_request : std_logic;
|
signal set_arp_entry_request : std_logic;
|
|
|
signal set_mac5 : std_logic;
|
signal set_mac5 : std_logic;
|
signal set_mac4 : std_logic;
|
signal set_mac4 : std_logic;
|
signal set_mac3 : std_logic;
|
signal set_mac3 : std_logic;
|
signal set_mac2 : std_logic;
|
signal set_mac2 : std_logic;
|
signal set_mac1 : std_logic;
|
signal set_mac1 : std_logic;
|
signal set_mac0 : std_logic;
|
signal set_mac0 : std_logic;
|
|
|
signal set_ip3 : std_logic;
|
signal set_ip3 : std_logic;
|
signal set_ip2 : std_logic;
|
signal set_ip2 : std_logic;
|
signal set_ip1 : std_logic;
|
signal set_ip1 : std_logic;
|
signal set_ip0 : std_logic;
|
signal set_ip0 : std_logic;
|
|
|
-- tx control signals
|
-- tx control signals
|
signal next_tx_state : tx_state_type;
|
signal next_tx_state : tx_state_type;
|
signal set_tx_state : std_logic;
|
signal set_tx_state : std_logic;
|
signal tx_count_mode : count_mode_type;
|
signal tx_count_mode : count_mode_type;
|
signal clear_reply_req : std_logic;
|
signal clear_reply_req : std_logic;
|
signal set_chn_reqd : set_clr_type;
|
signal set_chn_reqd : set_clr_type;
|
signal kill_data_out_valid : std_logic;
|
signal kill_data_out_valid : std_logic;
|
|
|
|
|
-- function to determine whether the rx pkt is an arp pkt and whether we want to process it
|
-- function to determine whether the rx pkt is an arp pkt and whether we want to process it
|
-- Returns 1 if we should discard
|
-- Returns 1 if we should discard
|
-- The following will make us ignore the frame (all values hexadecimal):
|
-- The following will make us ignore the frame (all values hexadecimal):
|
-- PDU type /= 0806
|
-- PDU type /= 0806
|
-- Protocol Type /= 0800
|
-- Protocol Type /= 0800
|
-- Hardware Type /= 1
|
-- Hardware Type /= 1
|
-- Hardware Length /= 6
|
-- Hardware Length /= 6
|
-- Protocol Length /= 4
|
-- Protocol Length /= 4
|
-- Operation /= 1 or 2
|
-- Operation /= 1 or 2
|
-- Target IP /= our IP (i.er. message is not meant for us)
|
-- Target IP /= our IP (i.er. message is not meant for us)
|
--
|
--
|
function not_our_arp(data : STD_LOGIC_VECTOR; count : unsigned; our_ip : std_logic_vector) return std_logic is
|
function not_our_arp(data : STD_LOGIC_VECTOR; count : unsigned; our_ip : std_logic_vector) return std_logic is
|
begin
|
begin
|
if
|
if
|
(count = 12 and data /= x"08") or -- PDU type 0806 : ARP
|
(count = 12 and data /= x"08") or -- PDU type 0806 : ARP
|
(count = 13 and data /= x"06") or
|
(count = 13 and data /= x"06") or
|
(count = 14 and data /= x"00") or -- HW type 1 : eth
|
(count = 14 and data /= x"00") or -- HW type 1 : eth
|
(count = 15 and data /= x"01") or
|
(count = 15 and data /= x"01") or
|
(count = 16 and data /= x"08") or -- Protocol 0800 : IP
|
(count = 16 and data /= x"08") or -- Protocol 0800 : IP
|
(count = 17 and data /= x"00") or
|
(count = 17 and data /= x"00") or
|
(count = 18 and data /= x"06") or -- HW Length 6
|
(count = 18 and data /= x"06") or -- HW Length 6
|
(count = 19 and data /= x"04") or -- protocol length 4
|
(count = 19 and data /= x"04") or -- protocol length 4
|
(count = 20 and data /= x"00") or -- operation 1 or 2 (req or reply)
|
(count = 20 and data /= x"00") or -- operation 1 or 2 (req or reply)
|
(count = 21 and data /= x"01" and data /= x"02") or
|
(count = 21 and data /= x"01" and data /= x"02") or
|
(count = 38 and data /= our_ip(31 downto 24)) or -- target IP is ours
|
(count = 38 and data /= our_ip(31 downto 24)) or -- target IP is ours
|
(count = 39 and data /= our_ip(23 downto 16)) or
|
(count = 39 and data /= our_ip(23 downto 16)) or
|
(count = 40 and data /= our_ip(15 downto 8)) or
|
(count = 40 and data /= our_ip(15 downto 8)) or
|
(count = 41 and data /= our_ip(7 downto 0))
|
(count = 41 and data /= our_ip(7 downto 0))
|
then
|
then
|
return '1';
|
return '1';
|
else
|
else
|
return '0';
|
return '0';
|
end if;
|
end if;
|
end function not_our_arp;
|
end function not_our_arp;
|
|
|
begin
|
begin
|
req_combinatorial : process (
|
req_combinatorial : process (
|
-- input signals
|
-- input signals
|
arp_req_req,
|
arp_req_req,
|
-- state variables
|
-- state variables
|
req_state, req_ip_addr, mac_addr_found, mac_addr_valid_reg, send_request_needed, arp_entry,
|
req_state, req_ip_addr, mac_addr_found, mac_addr_valid_reg, send_request_needed, arp_entry,
|
freq_scaler, timer, timeout_reg,
|
freq_scaler, timer, timeout_reg,
|
-- control signals
|
-- control signals
|
next_req_state, set_req_state, set_req_ip, set_mac_addr, control,
|
next_req_state, set_req_state, set_req_ip, set_mac_addr, control,
|
set_mac_addr_invalid,set_send_req, clear_send_req, set_timer, timer_enable, set_timeout
|
set_mac_addr_invalid,set_send_req, clear_send_req, set_timer, timer_enable, set_timeout
|
)
|
)
|
begin
|
begin
|
-- set output followers
|
-- set output followers
|
if arp_req_req.lookup_req = '1' then
|
if arp_req_req.lookup_req = '1' then
|
arp_req_rslt.got_err <= '0';
|
arp_req_rslt.got_err <= '0';
|
else
|
else
|
arp_req_rslt.got_err <= timeout_reg;
|
arp_req_rslt.got_err <= timeout_reg;
|
end if;
|
end if;
|
-- zero time response to lookup request if already in cache
|
-- zero time response to lookup request if already in cache
|
if arp_req_req.lookup_req = '1' and arp_req_req.ip = arp_entry.ip and arp_entry.is_valid = '1' then
|
if arp_req_req.lookup_req = '1' and arp_req_req.ip = arp_entry.ip and arp_entry.is_valid = '1' then
|
arp_req_rslt.got_mac <= '1';
|
arp_req_rslt.got_mac <= '1';
|
arp_req_rslt.mac <= arp_entry.mac;
|
arp_req_rslt.mac <= arp_entry.mac;
|
elsif arp_req_req.lookup_req = '1' then
|
elsif arp_req_req.lookup_req = '1' then
|
arp_req_rslt.got_mac <= '0'; -- hold off got_mac while req is there as arp_entry will not be correct yet
|
arp_req_rslt.got_mac <= '0'; -- hold off got_mac while req is there as arp_entry will not be correct yet
|
arp_req_rslt.mac <= arp_entry.mac;
|
arp_req_rslt.mac <= arp_entry.mac;
|
else
|
else
|
arp_req_rslt.got_mac <= mac_addr_valid_reg;
|
arp_req_rslt.got_mac <= mac_addr_valid_reg;
|
arp_req_rslt.mac <= mac_addr_found;
|
arp_req_rslt.mac <= mac_addr_found;
|
end if;
|
end if;
|
|
|
-- set signal defaults
|
-- set signal defaults
|
next_req_state <= IDLE;
|
next_req_state <= IDLE;
|
set_req_state <= '0';
|
set_req_state <= '0';
|
set_req_ip <= '0';
|
set_req_ip <= '0';
|
set_mac_addr <= '0';
|
set_mac_addr <= '0';
|
set_mac_addr_invalid <= '0';
|
set_mac_addr_invalid <= '0';
|
set_send_req <= '0';
|
set_send_req <= '0';
|
clear_send_req <= '0';
|
clear_send_req <= '0';
|
set_timer <= INCR; -- default is timer running, unless we hold or reset it
|
set_timer <= INCR; -- default is timer running, unless we hold or reset it
|
set_timeout <= HOLD;
|
set_timeout <= HOLD;
|
timer_enable <= '0';
|
timer_enable <= '0';
|
|
|
-- combinatorial logic
|
-- combinatorial logic
|
if freq_scaler = x"00000000" then
|
if freq_scaler = x"00000000" then
|
timer_enable <= '1';
|
timer_enable <= '1';
|
end if;
|
end if;
|
|
|
-- REQ FSM
|
-- REQ FSM
|
case req_state is
|
case req_state is
|
when IDLE =>
|
when IDLE =>
|
set_timer <= RST;
|
set_timer <= RST;
|
if arp_req_req.lookup_req = '1' then
|
if arp_req_req.lookup_req = '1' then
|
-- check if we already have the info in cache
|
-- check if we already have the info in cache
|
if arp_req_req.ip = arp_entry.ip and arp_entry.is_valid = '1' then
|
if arp_req_req.ip = arp_entry.ip and arp_entry.is_valid = '1' then
|
-- already have this IP
|
-- already have this IP
|
set_mac_addr <= '1';
|
set_mac_addr <= '1';
|
else
|
else
|
set_timeout <= CLR;
|
set_timeout <= CLR;
|
next_req_state <= LOOKUP;
|
next_req_state <= LOOKUP;
|
set_req_state <= '1';
|
set_req_state <= '1';
|
set_req_ip <= '1';
|
set_req_ip <= '1';
|
set_mac_addr_invalid <= '1';
|
set_mac_addr_invalid <= '1';
|
end if;
|
end if;
|
end if;
|
end if;
|
|
|
when LOOKUP =>
|
when LOOKUP =>
|
if arp_entry.ip = req_ip_addr and arp_entry.is_valid = '1' then
|
if arp_entry.ip = req_ip_addr and arp_entry.is_valid = '1' then
|
-- already have this IP
|
-- already have this IP
|
next_req_state <= IDLE;
|
next_req_state <= IDLE;
|
set_req_state <= '1';
|
set_req_state <= '1';
|
set_mac_addr <= '1';
|
set_mac_addr <= '1';
|
else
|
else
|
-- need to request mac for this IP
|
-- need to request mac for this IP
|
set_send_req <= '1';
|
set_send_req <= '1';
|
set_timer <= RST;
|
set_timer <= RST;
|
next_req_state <= REQUEST;
|
next_req_state <= REQUEST;
|
set_req_state <= '1';
|
set_req_state <= '1';
|
end if;
|
end if;
|
|
|
when REQUEST =>
|
when REQUEST =>
|
clear_send_req <= '1';
|
clear_send_req <= '1';
|
next_req_state <= WAIT_REPLY;
|
next_req_state <= WAIT_REPLY;
|
set_req_state <= '1';
|
set_req_state <= '1';
|
|
|
when WAIT_REPLY =>
|
when WAIT_REPLY =>
|
if arp_entry.is_valid = '1' then
|
if arp_entry.is_valid = '1' then
|
-- have reply, go back to LOOKUP state to see if it is the right one
|
-- have reply, go back to LOOKUP state to see if it is the right one
|
next_req_state <= LOOKUP;
|
next_req_state <= LOOKUP;
|
set_req_state <= '1';
|
set_req_state <= '1';
|
end if;
|
end if;
|
if timer >= ARP_TIMEOUT then
|
if timer >= ARP_TIMEOUT then
|
set_timeout <= SET;
|
set_timeout <= SET;
|
next_req_state <= PAUSE1;
|
next_req_state <= PAUSE1;
|
set_req_state <= '1';
|
set_req_state <= '1';
|
end if;
|
end if;
|
|
|
when PAUSE1 =>
|
when PAUSE1 =>
|
next_req_state <= PAUSE2;
|
next_req_state <= PAUSE2;
|
set_req_state <= '1';
|
set_req_state <= '1';
|
|
|
when PAUSE2 =>
|
when PAUSE2 =>
|
next_req_state <= PAUSE3;
|
next_req_state <= PAUSE3;
|
set_req_state <= '1';
|
set_req_state <= '1';
|
|
|
when PAUSE3 =>
|
when PAUSE3 =>
|
next_req_state <= IDLE;
|
next_req_state <= IDLE;
|
set_req_state <= '1';
|
set_req_state <= '1';
|
|
|
end case;
|
end case;
|
end process;
|
end process;
|
|
|
req_sequential : process (data_in_clk,reset)
|
req_sequential : process (data_in_clk,reset)
|
begin
|
begin
|
if rising_edge(data_in_clk) then
|
if rising_edge(data_in_clk) then
|
if reset = '1' then
|
if reset = '1' then
|
-- reset state variables
|
-- reset state variables
|
req_state <= IDLE;
|
req_state <= IDLE;
|
req_ip_addr <= (others => '0');
|
req_ip_addr <= (others => '0');
|
mac_addr_found <= (others => '0');
|
mac_addr_found <= (others => '0');
|
mac_addr_valid_reg <= '0';
|
mac_addr_valid_reg <= '0';
|
send_request_needed <= '0';
|
send_request_needed <= '0';
|
freq_scaler <= to_unsigned(CLOCK_FREQ,32);
|
freq_scaler <= to_unsigned(CLOCK_FREQ,32);
|
timer <= (others => '0');
|
timer <= (others => '0');
|
timeout_reg <= '0';
|
timeout_reg <= '0';
|
else
|
else
|
-- Next req_state processing
|
-- Next req_state processing
|
if set_req_state = '1' then
|
if set_req_state = '1' then
|
req_state <= next_req_state;
|
req_state <= next_req_state;
|
else
|
else
|
req_state <= req_state;
|
req_state <= req_state;
|
end if;
|
end if;
|
|
|
-- Latch the requested IP address
|
-- Latch the requested IP address
|
if set_req_ip = '1' then
|
if set_req_ip = '1' then
|
req_ip_addr <= arp_req_req.ip;
|
req_ip_addr <= arp_req_req.ip;
|
else
|
else
|
req_ip_addr <= req_ip_addr;
|
req_ip_addr <= req_ip_addr;
|
end if;
|
end if;
|
|
|
-- send request to TX&RX FSMs to send an ARP request
|
-- send request to TX&RX FSMs to send an ARP request
|
if set_send_req = '1' then
|
if set_send_req = '1' then
|
send_request_needed <= '1';
|
send_request_needed <= '1';
|
elsif clear_send_req = '1' then
|
elsif clear_send_req = '1' then
|
send_request_needed <= '0';
|
send_request_needed <= '0';
|
else
|
else
|
send_request_needed <= send_request_needed;
|
send_request_needed <= send_request_needed;
|
end if;
|
end if;
|
|
|
-- Set the found mac address
|
-- Set the found mac address
|
if set_mac_addr = '1' then
|
if set_mac_addr = '1' then
|
mac_addr_found <= arp_entry.mac;
|
mac_addr_found <= arp_entry.mac;
|
mac_addr_valid_reg <= '1';
|
mac_addr_valid_reg <= '1';
|
elsif set_mac_addr_invalid = '1' then
|
elsif set_mac_addr_invalid = '1' then
|
mac_addr_found <= (others => '0');
|
mac_addr_found <= (others => '0');
|
mac_addr_valid_reg <= '0';
|
mac_addr_valid_reg <= '0';
|
else
|
else
|
mac_addr_found <= mac_addr_found;
|
mac_addr_found <= mac_addr_found;
|
mac_addr_valid_reg <= mac_addr_valid_reg;
|
mac_addr_valid_reg <= mac_addr_valid_reg;
|
end if;
|
end if;
|
|
|
-- freq scaling and 1-sec timer
|
-- freq scaling and 1-sec timer
|
if freq_scaler = x"00000000" then
|
if freq_scaler = x"00000000" then
|
freq_scaler <= to_unsigned(CLOCK_FREQ,32);
|
freq_scaler <= to_unsigned(CLOCK_FREQ,32);
|
else
|
else
|
freq_scaler <= freq_scaler - 1;
|
freq_scaler <= freq_scaler - 1;
|
end if;
|
end if;
|
|
|
-- timer processing
|
-- timer processing
|
case set_timer is
|
case set_timer is
|
when RST =>
|
when RST =>
|
timer <= x"00";
|
timer <= x"00";
|
when INCR =>
|
when INCR =>
|
if timer_enable = '1' then
|
if timer_enable = '1' then
|
timer <= timer + 1;
|
timer <= timer + 1;
|
else
|
else
|
timer <= timer;
|
timer <= timer;
|
end if;
|
end if;
|
when HOLD =>
|
when HOLD =>
|
timer <= timer;
|
timer <= timer;
|
end case;
|
end case;
|
|
|
-- timeout latching
|
-- timeout latching
|
case set_timeout is
|
case set_timeout is
|
when CLR => timeout_reg <= '0';
|
when CLR => timeout_reg <= '0';
|
when SET => timeout_reg <= '1';
|
when SET => timeout_reg <= '1';
|
when HOLD => timeout_reg <= timeout_reg;
|
when HOLD => timeout_reg <= timeout_reg;
|
end case;
|
end case;
|
|
|
end if;
|
end if;
|
end if;
|
end if;
|
end process;
|
end process;
|
|
|
|
|
rx_combinatorial : process (
|
rx_combinatorial : process (
|
-- input signals
|
-- input signals
|
data_in, data_in_valid, data_in_last, our_ip_address,
|
data_in, data_in_valid, data_in_last, our_ip_address,
|
-- state variables
|
-- state variables
|
rx_state, rx_count, arp_operation, arp_req_count, arp_err_data,
|
rx_state, rx_count, arp_operation, arp_req_count, arp_err_data,
|
-- control signals
|
-- control signals
|
next_rx_state, set_rx_state, rx_event, rx_count_mode, set_arp_oper, arp_oper_set_val,
|
next_rx_state, set_rx_state, rx_event, rx_count_mode, set_arp_oper, arp_oper_set_val,
|
dataval,set_mac5,set_mac4,set_mac3,set_mac2,set_mac1,set_mac0,set_ip3,set_ip2,set_ip1,set_ip0, set_err_data,
|
dataval,set_mac5,set_mac4,set_mac3,set_mac2,set_mac1,set_mac0,set_ip3,set_ip2,set_ip1,set_ip0, set_err_data,
|
set_arp_entry_request)
|
set_arp_entry_request)
|
begin
|
begin
|
-- set output followers
|
-- set output followers
|
req_count <= STD_LOGIC_VECTOR(arp_req_count);
|
req_count <= STD_LOGIC_VECTOR(arp_req_count);
|
|
|
-- set signal defaults
|
-- set signal defaults
|
next_rx_state <= IDLE;
|
next_rx_state <= IDLE;
|
set_rx_state <= '0';
|
set_rx_state <= '0';
|
rx_event <= NO_EVENT;
|
rx_event <= NO_EVENT;
|
rx_count_mode <= HOLD;
|
rx_count_mode <= HOLD;
|
set_arp_oper <= '0';
|
set_arp_oper <= '0';
|
arp_oper_set_val <= NOP;
|
arp_oper_set_val <= NOP;
|
dataval <= (others => '0');
|
dataval <= (others => '0');
|
set_mac5 <= '0';
|
set_mac5 <= '0';
|
set_mac4 <= '0';
|
set_mac4 <= '0';
|
set_mac3 <= '0';
|
set_mac3 <= '0';
|
set_mac2 <= '0';
|
set_mac2 <= '0';
|
set_mac1 <= '0';
|
set_mac1 <= '0';
|
set_mac0 <= '0';
|
set_mac0 <= '0';
|
set_ip3 <= '0';
|
set_ip3 <= '0';
|
set_ip2 <= '0';
|
set_ip2 <= '0';
|
set_ip1 <= '0';
|
set_ip1 <= '0';
|
set_ip0 <= '0';
|
set_ip0 <= '0';
|
set_arp_entry_request <= '0';
|
set_arp_entry_request <= '0';
|
set_err_data <= '0';
|
set_err_data <= '0';
|
|
|
-- determine event (if any)
|
-- determine event (if any)
|
if data_in_valid = '1' then
|
if data_in_valid = '1' then
|
rx_event <= DATA;
|
rx_event <= DATA;
|
end if;
|
end if;
|
|
|
-- RX FSM
|
-- RX FSM
|
case rx_state is
|
case rx_state is
|
when IDLE =>
|
when IDLE =>
|
rx_count_mode <= RST;
|
rx_count_mode <= RST;
|
case rx_event is
|
case rx_event is
|
when NO_EVENT => -- (nothing to do)
|
when NO_EVENT => -- (nothing to do)
|
when DATA =>
|
when DATA =>
|
next_rx_state <= PARSE;
|
next_rx_state <= PARSE;
|
set_rx_state <= '1';
|
set_rx_state <= '1';
|
rx_count_mode <= INCR;
|
rx_count_mode <= INCR;
|
end case;
|
end case;
|
|
|
when PARSE =>
|
when PARSE =>
|
case rx_event is
|
case rx_event is
|
when NO_EVENT => -- (nothing to do)
|
when NO_EVENT => -- (nothing to do)
|
when DATA =>
|
when DATA =>
|
rx_count_mode <= INCR;
|
rx_count_mode <= INCR;
|
-- handle early frame termination
|
-- handle early frame termination
|
if data_in_last = '1' then
|
if data_in_last = '1' then
|
next_rx_state <= IDLE;
|
next_rx_state <= IDLE;
|
set_rx_state <= '1';
|
set_rx_state <= '1';
|
else
|
else
|
-- check for end of frame. Also, detect and discard if not our frame
|
-- check for end of frame. Also, detect and discard if not our frame
|
if rx_count = 42 then
|
if rx_count = 42 then
|
next_rx_state <= PROCESS_ARP;
|
next_rx_state <= PROCESS_ARP;
|
set_rx_state <= '1';
|
set_rx_state <= '1';
|
elsif not_our_arp(data_in,rx_count,our_ip_address) = '1' then
|
elsif not_our_arp(data_in,rx_count,our_ip_address) = '1' then
|
dataval <= data_in;
|
dataval <= data_in;
|
set_err_data <= '1';
|
set_err_data <= '1';
|
next_rx_state <= WAIT_END;
|
next_rx_state <= WAIT_END;
|
set_rx_state <= '1';
|
set_rx_state <= '1';
|
elsif rx_count = 21 then
|
elsif rx_count = 21 then
|
-- capture ARP operation
|
-- capture ARP operation
|
case data_in is
|
case data_in is
|
when x"01" =>
|
when x"01" =>
|
arp_oper_set_val <= REQUEST;
|
arp_oper_set_val <= REQUEST;
|
set_arp_oper <= '1';
|
set_arp_oper <= '1';
|
when x"02" =>
|
when x"02" =>
|
arp_oper_set_val <= REPLY;
|
arp_oper_set_val <= REPLY;
|
set_arp_oper <= '1';
|
set_arp_oper <= '1';
|
when others => -- ignore other values
|
when others => -- ignore other values
|
end case;
|
end case;
|
-- capture source mac addr
|
-- capture source mac addr
|
elsif rx_count = 22 then
|
elsif rx_count = 22 then
|
set_mac5 <= '1';
|
set_mac5 <= '1';
|
dataval <= data_in;
|
dataval <= data_in;
|
elsif rx_count = 23 then
|
elsif rx_count = 23 then
|
set_mac4 <= '1';
|
set_mac4 <= '1';
|
dataval <= data_in;
|
dataval <= data_in;
|
elsif rx_count = 24 then
|
elsif rx_count = 24 then
|
set_mac3 <= '1';
|
set_mac3 <= '1';
|
dataval <= data_in;
|
dataval <= data_in;
|
elsif rx_count = 25 then
|
elsif rx_count = 25 then
|
set_mac2 <= '1';
|
set_mac2 <= '1';
|
dataval <= data_in;
|
dataval <= data_in;
|
elsif rx_count = 26 then
|
elsif rx_count = 26 then
|
set_mac1 <= '1';
|
set_mac1 <= '1';
|
dataval <= data_in;
|
dataval <= data_in;
|
elsif rx_count = 27 then
|
elsif rx_count = 27 then
|
set_mac0 <= '1';
|
set_mac0 <= '1';
|
dataval <= data_in;
|
dataval <= data_in;
|
-- capture source ip addr
|
-- capture source ip addr
|
elsif rx_count = 28 then
|
elsif rx_count = 28 then
|
set_ip3 <= '1';
|
set_ip3 <= '1';
|
dataval <= data_in;
|
dataval <= data_in;
|
elsif rx_count = 29 then
|
elsif rx_count = 29 then
|
set_ip2 <= '1';
|
set_ip2 <= '1';
|
dataval <= data_in;
|
dataval <= data_in;
|
elsif rx_count = 30 then
|
elsif rx_count = 30 then
|
set_ip1 <= '1';
|
set_ip1 <= '1';
|
dataval <= data_in;
|
dataval <= data_in;
|
elsif rx_count = 31 then
|
elsif rx_count = 31 then
|
set_ip0 <= '1';
|
set_ip0 <= '1';
|
dataval <= data_in;
|
dataval <= data_in;
|
end if;
|
end if;
|
end if;
|
end if;
|
end case;
|
end case;
|
|
|
when PROCESS_ARP =>
|
when PROCESS_ARP =>
|
next_rx_state <= WAIT_END;
|
next_rx_state <= WAIT_END;
|
set_rx_state <= '1';
|
set_rx_state <= '1';
|
case arp_operation is
|
case arp_operation is
|
when NOP => -- (nothing to do)
|
when NOP => -- (nothing to do)
|
when REQUEST =>
|
when REQUEST =>
|
set_arp_entry_request <= '1';
|
set_arp_entry_request <= '1';
|
arp_oper_set_val <= NOP;
|
arp_oper_set_val <= NOP;
|
set_arp_oper <= '1';
|
set_arp_oper <= '1';
|
when REPLY =>
|
when REPLY =>
|
set_arp_entry_request <= '1';
|
set_arp_entry_request <= '1';
|
arp_oper_set_val <= NOP;
|
arp_oper_set_val <= NOP;
|
set_arp_oper <= '1';
|
set_arp_oper <= '1';
|
end case;
|
end case;
|
|
|
when WAIT_END =>
|
when WAIT_END =>
|
case rx_event is
|
case rx_event is
|
when NO_EVENT => -- (nothing to do)
|
when NO_EVENT => -- (nothing to do)
|
when DATA =>
|
when DATA =>
|
if data_in_last = '1' then
|
if data_in_last = '1' then
|
next_rx_state <= IDLE;
|
next_rx_state <= IDLE;
|
set_rx_state <= '1';
|
set_rx_state <= '1';
|
end if;
|
end if;
|
end case;
|
end case;
|
|
|
end case;
|
end case;
|
|
|
end process;
|
end process;
|
|
|
rx_sequential : process (data_in_clk)
|
rx_sequential : process (data_in_clk)
|
begin
|
begin
|
if rising_edge(data_in_clk) then
|
if rising_edge(data_in_clk) then
|
if reset = '1' then
|
if reset = '1' then
|
-- reset state variables
|
-- reset state variables
|
rx_state <= IDLE;
|
rx_state <= IDLE;
|
rx_count <= x"00";
|
rx_count <= x"00";
|
arp_operation <= NOP;
|
arp_operation <= NOP;
|
arp_req_count <= x"00";
|
arp_req_count <= x"00";
|
-- reset arp entry store
|
-- reset arp entry store
|
arp_entry.ip <= x"00000000";
|
arp_entry.ip <= x"00000000";
|
arp_entry.mac <= x"000000000000";
|
arp_entry.mac <= x"000000000000";
|
arp_entry.is_valid <= '0';
|
arp_entry.is_valid <= '0';
|
arp_entry.reply_required <= '0';
|
arp_entry.reply_required <= '0';
|
arp_err_data <= (others => '0');
|
arp_err_data <= (others => '0');
|
else
|
else
|
-- Next rx_state processing
|
-- Next rx_state processing
|
if set_rx_state = '1' then
|
if set_rx_state = '1' then
|
rx_state <= next_rx_state;
|
rx_state <= next_rx_state;
|
else
|
else
|
rx_state <= rx_state;
|
rx_state <= rx_state;
|
end if;
|
end if;
|
|
|
-- rx_count processing
|
-- rx_count processing
|
case rx_count_mode is
|
case rx_count_mode is
|
when RST =>
|
when RST =>
|
rx_count <= x"00";
|
rx_count <= x"00";
|
when INCR =>
|
when INCR =>
|
rx_count <= rx_count + 1;
|
rx_count <= rx_count + 1;
|
when HOLD =>
|
when HOLD =>
|
rx_count <= rx_count;
|
rx_count <= rx_count;
|
end case;
|
end case;
|
|
|
-- err data
|
-- err data
|
if set_err_data = '1' then
|
if set_err_data = '1' then
|
arp_err_data <= data_in;
|
arp_err_data <= data_in;
|
else
|
else
|
arp_err_data <= arp_err_data;
|
arp_err_data <= arp_err_data;
|
end if;
|
end if;
|
|
|
-- arp operation processing
|
-- arp operation processing
|
if set_arp_oper = '1' then
|
if set_arp_oper = '1' then
|
arp_operation <= arp_oper_set_val;
|
arp_operation <= arp_oper_set_val;
|
else
|
else
|
arp_operation <= arp_operation;
|
arp_operation <= arp_operation;
|
end if;
|
end if;
|
|
|
-- source mac capture
|
-- source mac capture
|
if (set_mac5 = '1') then new_arp_entry.mac(47 downto 40) <= dataval; end if;
|
if (set_mac5 = '1') then new_arp_entry.mac(47 downto 40) <= dataval; end if;
|
if (set_mac4 = '1') then new_arp_entry.mac(39 downto 32) <= dataval; end if;
|
if (set_mac4 = '1') then new_arp_entry.mac(39 downto 32) <= dataval; end if;
|
if (set_mac3 = '1') then new_arp_entry.mac(31 downto 24) <= dataval; end if;
|
if (set_mac3 = '1') then new_arp_entry.mac(31 downto 24) <= dataval; end if;
|
if (set_mac2 = '1') then new_arp_entry.mac(23 downto 16) <= dataval; end if;
|
if (set_mac2 = '1') then new_arp_entry.mac(23 downto 16) <= dataval; end if;
|
if (set_mac1 = '1') then new_arp_entry.mac(15 downto 8) <= dataval; end if;
|
if (set_mac1 = '1') then new_arp_entry.mac(15 downto 8) <= dataval; end if;
|
if (set_mac0 = '1') then new_arp_entry.mac(7 downto 0) <= dataval; end if;
|
if (set_mac0 = '1') then new_arp_entry.mac(7 downto 0) <= dataval; end if;
|
|
|
-- source ip capture
|
-- source ip capture
|
if (set_ip3 = '1') then new_arp_entry.ip(31 downto 24) <= dataval; end if;
|
if (set_ip3 = '1') then new_arp_entry.ip(31 downto 24) <= dataval; end if;
|
if (set_ip2 = '1') then new_arp_entry.ip(23 downto 16) <= dataval; end if;
|
if (set_ip2 = '1') then new_arp_entry.ip(23 downto 16) <= dataval; end if;
|
if (set_ip1 = '1') then new_arp_entry.ip(15 downto 8) <= dataval; end if;
|
if (set_ip1 = '1') then new_arp_entry.ip(15 downto 8) <= dataval; end if;
|
if (set_ip0 = '1') then new_arp_entry.ip(7 downto 0) <= dataval; end if;
|
if (set_ip0 = '1') then new_arp_entry.ip(7 downto 0) <= dataval; end if;
|
|
|
-- set arp entry request
|
-- set arp entry request
|
if control.clear_cache = '1' then
|
if control.clear_cache = '1' then
|
arp_entry.ip <= x"00000000";
|
arp_entry.ip <= x"00000000";
|
arp_entry.mac <= x"000000000000";
|
arp_entry.mac <= x"000000000000";
|
arp_entry.is_valid <= '0';
|
arp_entry.is_valid <= '0';
|
arp_entry.reply_required <= '0';
|
arp_entry.reply_required <= '0';
|
elsif set_arp_entry_request = '1' then
|
elsif set_arp_entry_request = '1' then
|
-- copy info from new entry to arp_entry and set reply required
|
-- copy info from new entry to arp_entry and set reply required
|
arp_entry.mac <= new_arp_entry.mac;
|
arp_entry.mac <= new_arp_entry.mac;
|
arp_entry.ip <= new_arp_entry.ip;
|
arp_entry.ip <= new_arp_entry.ip;
|
arp_entry.is_valid <= '1';
|
arp_entry.is_valid <= '1';
|
if arp_operation = REQUEST then
|
if arp_operation = REQUEST then
|
arp_entry.reply_required <= '1';
|
arp_entry.reply_required <= '1';
|
else
|
else
|
arp_entry.reply_required <= '0';
|
arp_entry.reply_required <= '0';
|
end if;
|
end if;
|
-- count another ARP pkt received
|
-- count another ARP pkt received
|
arp_req_count <= arp_req_count + 1;
|
arp_req_count <= arp_req_count + 1;
|
elsif clear_reply_req = '1' then
|
elsif clear_reply_req = '1' then
|
-- note: clear_reply_req is set by tx logic, but handled in the clk domain of the rx
|
-- note: clear_reply_req is set by tx logic, but handled in the clk domain of the rx
|
-- maintain arp entry state, but reset the reply required flag
|
-- maintain arp entry state, but reset the reply required flag
|
arp_entry.mac <= arp_entry.mac;
|
arp_entry.mac <= arp_entry.mac;
|
arp_entry.ip <= arp_entry.ip;
|
arp_entry.ip <= arp_entry.ip;
|
arp_entry.is_valid <= arp_entry.is_valid;
|
arp_entry.is_valid <= arp_entry.is_valid;
|
arp_entry.reply_required <= '0';
|
arp_entry.reply_required <= '0';
|
arp_req_count <= arp_req_count;
|
arp_req_count <= arp_req_count;
|
elsif send_request_needed = '1' then
|
elsif send_request_needed = '1' then
|
-- set up the arp entry to take the request to be transmitted out by the TX FSM
|
-- set up the arp entry to take the request to be transmitted out by the TX FSM
|
arp_entry.ip <= req_ip_addr;
|
arp_entry.ip <= req_ip_addr;
|
arp_entry.mac <= (others => '0');
|
arp_entry.mac <= (others => '0');
|
arp_entry.is_valid <= '0';
|
arp_entry.is_valid <= '0';
|
arp_entry.reply_required <= '0';
|
arp_entry.reply_required <= '0';
|
else
|
else
|
arp_entry <= arp_entry;
|
arp_entry <= arp_entry;
|
arp_req_count <= arp_req_count;
|
arp_req_count <= arp_req_count;
|
end if;
|
end if;
|
|
|
end if;
|
end if;
|
end if;
|
end if;
|
end process;
|
end process;
|
|
|
tx_combinatorial : process (
|
tx_combinatorial : process (
|
-- input signals
|
-- input signals
|
data_out_ready, send_request_needed, mac_tx_granted, our_mac_address, our_ip_address,
|
data_out_ready, send_request_needed, mac_tx_granted, our_mac_address, our_ip_address,
|
-- state variables
|
-- state variables
|
tx_state, tx_count, tx_mac_chn_reqd, arp_entry,
|
tx_state, tx_count, tx_mac_chn_reqd, arp_entry,
|
-- control signals
|
-- control signals
|
next_rx_state, set_rx_state, tx_count_mode, kill_data_out_valid,
|
next_rx_state, set_rx_state, tx_count_mode, kill_data_out_valid,
|
set_chn_reqd, clear_reply_req)
|
set_chn_reqd, clear_reply_req)
|
begin
|
begin
|
-- set output followers
|
-- set output followers
|
mac_tx_req <= tx_mac_chn_reqd;
|
mac_tx_req <= tx_mac_chn_reqd;
|
|
|
-- set initial values for combinatorial outputs
|
-- set initial values for combinatorial outputs
|
data_out_first <= '0';
|
data_out_first <= '0';
|
|
|
case tx_state is
|
case tx_state is
|
when SEND =>
|
when SEND =>
|
if data_out_ready = '1' and kill_data_out_valid = '0' then
|
if data_out_ready = '1' and kill_data_out_valid = '0' then
|
data_out_valid <= '1';
|
data_out_valid <= '1';
|
else
|
else
|
data_out_valid <= '0';
|
data_out_valid <= '0';
|
end if;
|
end if;
|
when OTHERS => data_out_valid <= '0';
|
when OTHERS => data_out_valid <= '0';
|
end case;
|
end case;
|
|
|
-- set signal defaults
|
-- set signal defaults
|
next_tx_state <= IDLE;
|
next_tx_state <= IDLE;
|
set_tx_state <= '0';
|
set_tx_state <= '0';
|
tx_count_mode <= HOLD;
|
tx_count_mode <= HOLD;
|
data_out <= x"00";
|
data_out <= x"00";
|
data_out_last <= '0';
|
data_out_last <= '0';
|
clear_reply_req <= '0';
|
clear_reply_req <= '0';
|
set_chn_reqd <= HOLD;
|
set_chn_reqd <= HOLD;
|
kill_data_out_valid <= '0';
|
kill_data_out_valid <= '0';
|
|
|
-- TX FSM
|
-- TX FSM
|
case tx_state is
|
case tx_state is
|
when IDLE =>
|
when IDLE =>
|
tx_count_mode <= RST;
|
tx_count_mode <= RST;
|
if arp_entry.reply_required = '1' then
|
if arp_entry.reply_required = '1' then
|
set_chn_reqd <= SET;
|
set_chn_reqd <= SET;
|
next_tx_state <= WAIT_MAC;
|
next_tx_state <= WAIT_MAC;
|
set_tx_state <= '1';
|
set_tx_state <= '1';
|
elsif send_request_needed = '1' then
|
elsif send_request_needed = '1' then
|
set_chn_reqd <= SET;
|
set_chn_reqd <= SET;
|
next_tx_state <= WAIT_MAC;
|
next_tx_state <= WAIT_MAC;
|
set_tx_state <= '1';
|
set_tx_state <= '1';
|
else
|
else
|
set_chn_reqd <= CLR;
|
set_chn_reqd <= CLR;
|
end if;
|
end if;
|
|
|
when WAIT_MAC =>
|
when WAIT_MAC =>
|
tx_count_mode <= RST;
|
tx_count_mode <= RST;
|
if mac_tx_granted = '1' then
|
if mac_tx_granted = '1' then
|
next_tx_state <= SEND;
|
next_tx_state <= SEND;
|
set_tx_state <= '1';
|
set_tx_state <= '1';
|
end if;
|
end if;
|
-- TODO - should handle timeout here
|
-- TODO - should handle timeout here
|
|
|
when SEND =>
|
when SEND =>
|
if data_out_ready = '1' then
|
if data_out_ready = '1' then
|
tx_count_mode <= INCR;
|
tx_count_mode <= INCR;
|
end if;
|
end if;
|
case tx_count is
|
case tx_count is
|
when x"00" =>
|
when x"00" =>
|
data_out_first <= data_out_ready;
|
data_out_first <= data_out_ready;
|
data_out <= x"ff"; -- dst = broadcast
|
data_out <= x"ff"; -- dst = broadcast
|
|
|
when x"01" => data_out <= x"ff";
|
when x"01" => data_out <= x"ff";
|
when x"02" => data_out <= x"ff";
|
when x"02" => data_out <= x"ff";
|
when x"03" => data_out <= x"ff";
|
when x"03" => data_out <= x"ff";
|
when x"04" => data_out <= x"ff";
|
when x"04" => data_out <= x"ff";
|
when x"05" => data_out <= x"ff";
|
when x"05" => data_out <= x"ff";
|
when x"06" => data_out <= our_mac_address (47 downto 40); -- src = our mac
|
when x"06" => data_out <= our_mac_address (47 downto 40); -- src = our mac
|
when x"07" => data_out <= our_mac_address (39 downto 32);
|
when x"07" => data_out <= our_mac_address (39 downto 32);
|
when x"08" => data_out <= our_mac_address (31 downto 24);
|
when x"08" => data_out <= our_mac_address (31 downto 24);
|
when x"09" => data_out <= our_mac_address (23 downto 16);
|
when x"09" => data_out <= our_mac_address (23 downto 16);
|
when x"0a" => data_out <= our_mac_address (15 downto 8);
|
when x"0a" => data_out <= our_mac_address (15 downto 8);
|
when x"0b" => data_out <= our_mac_address (7 downto 0);
|
when x"0b" => data_out <= our_mac_address (7 downto 0);
|
when x"0c" => data_out <= x"08"; -- pkt type = 0806 : ARP
|
when x"0c" => data_out <= x"08"; -- pkt type = 0806 : ARP
|
when x"0d" => data_out <= x"06";
|
when x"0d" => data_out <= x"06";
|
when x"0e" => data_out <= x"00"; -- HW type = 0001 : eth
|
when x"0e" => data_out <= x"00"; -- HW type = 0001 : eth
|
when x"0f" => data_out <= x"01";
|
when x"0f" => data_out <= x"01";
|
when x"10" => data_out <= x"08"; -- protocol = 0800 : ip
|
when x"10" => data_out <= x"08"; -- protocol = 0800 : ip
|
when x"11" => data_out <= x"00";
|
when x"11" => data_out <= x"00";
|
when x"12" => data_out <= x"06"; -- HW size = 06
|
when x"12" => data_out <= x"06"; -- HW size = 06
|
when x"13" => data_out <= x"04"; -- prot size = 04
|
when x"13" => data_out <= x"04"; -- prot size = 04
|
|
|
when x"14" => data_out <= x"00"; -- opcode =
|
when x"14" => data_out <= x"00"; -- opcode =
|
when x"15" =>
|
when x"15" =>
|
if arp_entry.is_valid = '1' then
|
if arp_entry.is_valid = '1' then
|
data_out <= x"02"; -- 02 : REPLY if arp_entry valid
|
data_out <= x"02"; -- 02 : REPLY if arp_entry valid
|
else
|
else
|
data_out <= x"01"; -- 01 : REQ if arp_entry invalid
|
data_out <= x"01"; -- 01 : REQ if arp_entry invalid
|
end if;
|
end if;
|
|
|
when x"16" => data_out <= our_mac_address (47 downto 40); -- sender mac
|
when x"16" => data_out <= our_mac_address (47 downto 40); -- sender mac
|
when x"17" => data_out <= our_mac_address (39 downto 32);
|
when x"17" => data_out <= our_mac_address (39 downto 32);
|
when x"18" => data_out <= our_mac_address (31 downto 24);
|
when x"18" => data_out <= our_mac_address (31 downto 24);
|
when x"19" => data_out <= our_mac_address (23 downto 16);
|
when x"19" => data_out <= our_mac_address (23 downto 16);
|
when x"1a" => data_out <= our_mac_address (15 downto 8);
|
when x"1a" => data_out <= our_mac_address (15 downto 8);
|
when x"1b" => data_out <= our_mac_address (7 downto 0);
|
when x"1b" => data_out <= our_mac_address (7 downto 0);
|
when x"1c" => data_out <= our_ip_address (31 downto 24); -- sender ip
|
when x"1c" => data_out <= our_ip_address (31 downto 24); -- sender ip
|
when x"1d" => data_out <= our_ip_address (23 downto 16);
|
when x"1d" => data_out <= our_ip_address (23 downto 16);
|
when x"1e" => data_out <= our_ip_address (15 downto 8);
|
when x"1e" => data_out <= our_ip_address (15 downto 8);
|
when x"1f" => data_out <= our_ip_address (7 downto 0);
|
when x"1f" => data_out <= our_ip_address (7 downto 0);
|
when x"20" => data_out <= arp_entry.mac (47 downto 40); -- target mac
|
when x"20" => data_out <= arp_entry.mac (47 downto 40); -- target mac
|
when x"21" => data_out <= arp_entry.mac (39 downto 32);
|
when x"21" => data_out <= arp_entry.mac (39 downto 32);
|
when x"22" => data_out <= arp_entry.mac (31 downto 24);
|
when x"22" => data_out <= arp_entry.mac (31 downto 24);
|
when x"23" => data_out <= arp_entry.mac (23 downto 16);
|
when x"23" => data_out <= arp_entry.mac (23 downto 16);
|
when x"24" => data_out <= arp_entry.mac (15 downto 8);
|
when x"24" => data_out <= arp_entry.mac (15 downto 8);
|
when x"25" => data_out <= arp_entry.mac (7 downto 0);
|
when x"25" => data_out <= arp_entry.mac (7 downto 0);
|
when x"26" => data_out <= arp_entry.ip (31 downto 24); -- target ip
|
when x"26" => data_out <= arp_entry.ip (31 downto 24); -- target ip
|
when x"27" => data_out <= arp_entry.ip (23 downto 16);
|
when x"27" => data_out <= arp_entry.ip (23 downto 16);
|
when x"28" => data_out <= arp_entry.ip (15 downto 8);
|
when x"28" => data_out <= arp_entry.ip (15 downto 8);
|
|
|
when x"29" =>
|
when x"29" =>
|
data_out <= arp_entry.ip(7 downto 0);
|
data_out <= arp_entry.ip(7 downto 0);
|
data_out_last <= '1';
|
data_out_last <= '1';
|
|
|
when x"2a" =>
|
when x"2a" =>
|
clear_reply_req <= '1'; -- reset the reply request (done in the rx clk process domain)
|
clear_reply_req <= '1'; -- reset the reply request (done in the rx clk process domain)
|
kill_data_out_valid <= '1'; -- data is no longer valid
|
kill_data_out_valid <= '1'; -- data is no longer valid
|
next_tx_state <= IDLE;
|
next_tx_state <= IDLE;
|
set_tx_state <= '1';
|
set_tx_state <= '1';
|
|
|
when others =>
|
when others =>
|
next_tx_state <= IDLE;
|
next_tx_state <= IDLE;
|
set_tx_state <= '1';
|
set_tx_state <= '1';
|
end case;
|
end case;
|
end case;
|
end case;
|
end process;
|
end process;
|
|
|
tx_sequential : process (data_out_clk,reset)
|
tx_sequential : process (data_out_clk,reset)
|
begin
|
begin
|
if rising_edge(data_out_clk) then
|
if rising_edge(data_out_clk) then
|
if reset = '1' then
|
if reset = '1' then
|
-- reset state variables
|
-- reset state variables
|
tx_state <= IDLE;
|
tx_state <= IDLE;
|
tx_mac_chn_reqd <= '0';
|
tx_mac_chn_reqd <= '0';
|
else
|
else
|
-- Next rx_state processing
|
-- Next rx_state processing
|
if set_tx_state = '1' then
|
if set_tx_state = '1' then
|
tx_state <= next_tx_state;
|
tx_state <= next_tx_state;
|
else
|
else
|
tx_state <= tx_state;
|
tx_state <= tx_state;
|
end if;
|
end if;
|
|
|
-- tx_count processing
|
-- tx_count processing
|
case tx_count_mode is
|
case tx_count_mode is
|
when RST =>
|
when RST =>
|
tx_count <= x"00";
|
tx_count <= x"00";
|
when INCR =>
|
when INCR =>
|
tx_count <= tx_count + 1;
|
tx_count <= tx_count + 1;
|
when HOLD =>
|
when HOLD =>
|
tx_count <= tx_count;
|
tx_count <= tx_count;
|
end case;
|
end case;
|
|
|
-- control access request to mac tx chn
|
-- control access request to mac tx chn
|
case set_chn_reqd is
|
case set_chn_reqd is
|
when SET => tx_mac_chn_reqd <= '1';
|
when SET => tx_mac_chn_reqd <= '1';
|
when CLR => tx_mac_chn_reqd <= '0';
|
when CLR => tx_mac_chn_reqd <= '0';
|
when HOLD => tx_mac_chn_reqd <= tx_mac_chn_reqd;
|
when HOLD => tx_mac_chn_reqd <= tx_mac_chn_reqd;
|
end case;
|
end case;
|
|
|
end if;
|
end if;
|
end if;
|
end if;
|
end process;
|
end process;
|
|
|
|
|
end Behavioral;
|
end Behavioral;
|
|
|
|
|
