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-- Revision 0.01 - File Created from arp.vhd 0.2
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-- Revision 0.01 - File Created from arp.vhd 0.2
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-- Additional Comments:
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-- Additional Comments:
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--
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--
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----------------------------------------------------------------------------------
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----------------------------------------------------------------------------------
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library IEEE;
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library IEEE;
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use IEEE.STD_LOGIC_1164.ALL;
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use IEEE.STD_LOGIC_1164.all;
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use IEEE.NUMERIC_STD.ALL;
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use IEEE.NUMERIC_STD.all;
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use work.arp_types.all;
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use work.arp_types.all;
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entity arp_req is
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entity arp_req is
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generic (
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generic (
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no_default_gateway : boolean := true; -- set to false if communicating with devices accessed
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-- through a "default gateway or router"
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CLOCK_FREQ : integer := 125000000; -- freq of data_in_clk -- needed to timout cntr
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CLOCK_FREQ : integer := 125000000; -- freq of data_in_clk -- needed to timout cntr
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ARP_TIMEOUT : integer := 60; -- ARP response timeout (s)
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ARP_TIMEOUT : integer := 60; -- ARP response timeout (s)
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ARP_MAX_PKT_TMO : integer := 5 -- # wrong nwk pkts received before set error
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ARP_MAX_PKT_TMO : integer := 5 -- # wrong nwk pkts received before set error
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);
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);
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Port (
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port (
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-- lookup request signals
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-- lookup request signals
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arp_req_req : in arp_req_req_type; -- request for a translation from IP to MAC
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arp_req_req : in arp_req_req_type; -- request for a translation from IP to MAC
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arp_req_rslt : out arp_req_rslt_type; -- the result
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arp_req_rslt : out arp_req_rslt_type; -- the result
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-- external arp store signals
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-- external arp store signals
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arp_store_req : out arp_store_rdrequest_t; -- requesting a lookup or store
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arp_store_req : out arp_store_rdrequest_t; -- requesting a lookup or store
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Line 42... |
-- network request signals
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-- network request signals
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arp_nwk_req : out arp_nwk_request_t; -- requesting resolution via the network
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arp_nwk_req : out arp_nwk_request_t; -- requesting resolution via the network
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arp_nwk_result : in arp_nwk_result_t; -- the result
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arp_nwk_result : in arp_nwk_result_t; -- the result
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-- system signals
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-- system signals
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clear_cache : in std_logic; -- clear the internal cache
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clear_cache : in std_logic; -- clear the internal cache
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nwk_gateway : in std_logic_vector(31 downto 0); -- IP address of default gateway
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nwk_mask : in std_logic_vector(31 downto 0); -- Net mask
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clk : in std_logic;
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clk : in std_logic;
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reset : in STD_LOGIC
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reset : in std_logic
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);
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);
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end arp_req;
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end arp_req;
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architecture Behavioral of arp_req is
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architecture Behavioral of arp_req is
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Line 79... |
signal set_timer : set_cntr_t; -- timer reset, count, hold control
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signal set_timer : set_cntr_t; -- timer reset, count, hold control
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signal timer_enable : std_logic; -- enable the timer counting
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signal timer_enable : std_logic; -- enable the timer counting
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signal set_timeout : set_clr_type; -- control the timeout register
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signal set_timeout : set_clr_type; -- control the timeout register
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signal clear_cache_valid : std_logic;
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signal clear_cache_valid : std_logic;
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signal l_arp_req_req_ip : std_logic_vector(31 downto 0); -- local network IP address for resolution
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begin
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begin
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default_GW: if (not no_default_gateway) generate
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default_gw_comb_p: process (arp_req_req.ip, nwk_gateway, nwk_mask) is
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begin -- process default_gw_comb_p
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-- translate IP addresses to local IP address if necessary
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if ((nwk_mask and arp_req_req.ip) = (nwk_mask and nwk_gateway)) then
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-- on local network
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l_arp_req_req_ip <= arp_req_req.ip;
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else
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-- on remote network
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l_arp_req_req_ip <= nwk_gateway;
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end if;
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end process default_gw_comb_p;
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end generate default_GW;
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no_default_GW: if (no_default_gateway) generate
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no_default_gw_comb_p: process (arp_req_req.ip) is
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begin -- process no_default_gw_comb_p
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l_arp_req_req_ip <= arp_req_req.ip;
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end process no_default_gw_comb_p;
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end generate no_default_GW;
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req_combinatorial : process (
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req_combinatorial : process (
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-- input signals
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arp_entry_cache.ip, arp_entry_cache.mac, arp_nwk_result.entry, arp_nwk_result.entry.ip,
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arp_req_req, arp_store_result, arp_nwk_result, clear_cache,
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arp_nwk_result.entry.mac, arp_nwk_result.status, arp_req_req.lookup_req,
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-- state variables
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arp_store_result.entry, arp_store_result.entry.mac, arp_store_result.status, cache_valid,
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req_state, req_ip_addr, arp_entry_cache, cache_valid, nwk_rx_cntr,
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clear_cache, freq_scaler, l_arp_req_req_ip, nwk_rx_cntr, req_ip_addr, req_state,
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freq_scaler, timer, timeout_reg,
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timeout_reg, timer)
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-- busses
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next_req_state, arp_entry_val,
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-- control signals
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set_req_state, set_req_ip, store_arp_cache, set_nwk_rx_cntr, clear_cache_valid,
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set_timer, timer_enable, set_timeout
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)
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begin
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begin
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-- set output followers
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-- set output followers
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arp_req_rslt.got_mac <= '0'; -- set initial value of request result outputs
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arp_req_rslt.got_mac <= '0'; -- set initial value of request result outputs
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arp_req_rslt.got_err <= '0';
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arp_req_rslt.got_err <= '0';
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arp_req_rslt.mac <= (others => '0');
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arp_req_rslt.mac <= (others => '0');
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Line 121... |
arp_store_req.ip <= (others => '0');
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arp_store_req.ip <= (others => '0');
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arp_nwk_req.req <= '0';
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arp_nwk_req.req <= '0';
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arp_nwk_req.ip <= (others => '0');
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arp_nwk_req.ip <= (others => '0');
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-- zero time response to lookup request if already in cache
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-- zero time response to lookup request if already in cache
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if arp_req_req.lookup_req = '1' and arp_req_req.ip = arp_entry_cache.ip and cache_valid = '1' then
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if arp_req_req.lookup_req = '1' and l_arp_req_req_ip = arp_entry_cache.ip and cache_valid = '1' then
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arp_req_rslt.got_mac <= '1';
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arp_req_rslt.got_mac <= '1';
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arp_req_rslt.mac <= arp_entry_cache.mac;
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arp_req_rslt.mac <= arp_entry_cache.mac;
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elsif arp_req_req.lookup_req = '1' then
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elsif arp_req_req.lookup_req = '1' then
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-- hold off got_mac while req is there as arp_entry will not be correct yet
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-- hold off got_mac while req is there as arp_entry will not be correct yet
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arp_req_rslt.got_mac <= '0';
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arp_req_rslt.got_mac <= '0';
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case req_state is
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case req_state is
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when IDLE =>
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when IDLE =>
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set_timer <= CLR;
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set_timer <= CLR;
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if arp_req_req.lookup_req = '1' then
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if arp_req_req.lookup_req = '1' then
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-- check if we already have the info in cache
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-- check if we already have the info in cache
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if arp_req_req.ip = arp_entry_cache.ip and cache_valid = '1' then
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if l_arp_req_req_ip = arp_entry_cache.ip and cache_valid = '1' then
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-- already have this IP - feed output back
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-- already have this IP - feed output back
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arp_req_rslt.got_mac <= '1';
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arp_req_rslt.got_mac <= '1';
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arp_req_rslt.mac <= arp_entry_cache.mac;
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arp_req_rslt.mac <= arp_entry_cache.mac;
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else
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else
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clear_cache_valid <= '1'; -- remove cache entry
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clear_cache_valid <= '1'; -- remove cache entry
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arp_nwk_req.req <= '1';
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arp_nwk_req.req <= '1';
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arp_nwk_req.ip <= req_ip_addr;
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arp_nwk_req.ip <= req_ip_addr;
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next_req_state <= WAIT_REPLY;
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next_req_state <= WAIT_REPLY;
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set_req_state <= '1';
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set_req_state <= '1';
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when OTHERS =>
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when others =>
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-- just keep waiting - no timeout (assumes lookup with either succeed or fail)
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-- just keep waiting - no timeout (assumes lookup with either succeed or fail)
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end case;
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end case;
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when WAIT_REPLY =>
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when WAIT_REPLY =>
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case arp_nwk_result.status is
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case arp_nwk_result.status is
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when RECEIVED =>
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when RECEIVED =>
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if arp_nwk_result.entry.ip = req_ip_addr then
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-- store into cache
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-- store into cache
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arp_entry_val <= arp_nwk_result.entry;
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arp_entry_val <= arp_nwk_result.entry;
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store_arp_cache <= '1';
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store_arp_cache <= '1';
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-- and feed output back
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-- and feed output back
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if arp_nwk_result.entry.ip = req_ip_addr then
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arp_req_rslt.got_mac <= '1';
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arp_req_rslt.got_mac <= '1';
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arp_req_rslt.mac <= arp_nwk_result.entry.mac;
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arp_req_rslt.mac <= arp_nwk_result.entry.mac;
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next_req_state <= IDLE;
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next_req_state <= IDLE;
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set_req_state <= '1';
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set_req_state <= '1';
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else
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else
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else
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else
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set_nwk_rx_cntr <= INCR;
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set_nwk_rx_cntr <= INCR;
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end if;
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end if;
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end if;
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end if;
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when ERROR =>
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when error =>
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set_timeout <= SET;
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set_timeout <= SET;
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when OTHERS =>
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when others =>
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if timer >= ARP_TIMEOUT then
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if timer >= ARP_TIMEOUT then
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set_timeout <= SET;
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set_timeout <= SET;
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next_req_state <= PAUSE1;
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next_req_state <= PAUSE1;
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set_req_state <= '1';
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set_req_state <= '1';
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end if;
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end if;
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req_state <= req_state;
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req_state <= req_state;
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end if;
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end if;
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-- Latch the requested IP address
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-- Latch the requested IP address
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if set_req_ip = '1' then
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if set_req_ip = '1' then
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req_ip_addr <= arp_req_req.ip;
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req_ip_addr <= l_arp_req_req_ip;
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else
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else
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req_ip_addr <= req_ip_addr;
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req_ip_addr <= req_ip_addr;
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end if;
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end if;
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-- network received counter
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-- network received counter
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