----------------------------------------------------------------------------------
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----------------------------------------------------------------------------------
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-- Company:
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-- Company:
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-- Engineer: Peter Fall
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-- Engineer: Peter Fall
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--
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--
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-- Create Date: 16:20:42 06/01/2011
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-- Create Date: 16:20:42 06/01/2011
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-- Design Name:
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-- Design Name:
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-- Module Name: IPv4_TX - Behavioral
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-- Module Name: IPv4_TX - Behavioral
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-- Project Name:
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-- Project Name:
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-- Target Devices:
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-- Target Devices:
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-- Tool versions:
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-- Tool versions:
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-- Description:
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-- Description:
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-- handle simple IP TX
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-- handle simple IP TX
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-- doesnt handle segmentation
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-- doesnt handle segmentation
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-- dest MAC addr resolution through ARP layer
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-- dest MAC addr resolution through ARP layer
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-- Handle IPv4 protocol
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-- Handle IPv4 protocol
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-- Dependencies:
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-- Dependencies:
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--
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--
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-- Revision:
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-- Revision:
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-- Revision 0.01 - File Created
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-- Revision 0.01 - File Created
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-- Revision 0.02 - fixed up setting of tx_result control defaults
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-- Revision 0.02 - fixed up setting of tx_result control defaults
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-- Revision 0.03 - Added data_out_first
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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.axi.all;
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use work.axi.all;
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use work.ipv4_types.all;
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use work.ipv4_types.all;
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use work.arp_types.all;
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use work.arp_types.all;
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|
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entity IPv4_TX is
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entity IPv4_TX is
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Port (
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Port (
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-- IP Layer signals
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-- IP Layer signals
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ip_tx_start : in std_logic;
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ip_tx_start : in std_logic;
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ip_tx : in ipv4_tx_type; -- IP tx cxns
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ip_tx : in ipv4_tx_type; -- IP tx cxns
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ip_tx_result : out std_logic_vector (1 downto 0); -- tx status (changes during transmission)
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ip_tx_result : out std_logic_vector (1 downto 0); -- tx status (changes during transmission)
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ip_tx_data_out_ready : out std_logic; -- indicates IP TX is ready to take data
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ip_tx_data_out_ready : out std_logic; -- indicates IP TX is ready to take data
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|
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-- system signals
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-- system signals
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clk : in STD_LOGIC; -- same clock used to clock mac data and ip data
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clk : in STD_LOGIC; -- same clock used to clock mac data and ip data
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reset : in STD_LOGIC;
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reset : in STD_LOGIC;
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our_ip_address : in STD_LOGIC_VECTOR (31 downto 0);
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our_ip_address : in STD_LOGIC_VECTOR (31 downto 0);
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our_mac_address : in std_logic_vector (47 downto 0);
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our_mac_address : in std_logic_vector (47 downto 0);
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-- ARP lookup signals
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-- ARP lookup signals
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arp_req_req : out arp_req_req_type;
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arp_req_req : out arp_req_req_type;
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arp_req_rslt : in arp_req_rslt_type;
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arp_req_rslt : in arp_req_rslt_type;
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-- MAC layer TX signals
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-- MAC layer TX signals
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mac_tx_req : out std_logic; -- indicates that ip wants access to channel (stays up for as long as tx)
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mac_tx_req : out std_logic; -- indicates that ip wants access to channel (stays up for as long as tx)
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mac_tx_granted : in std_logic; -- indicates that access to channel has been granted
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mac_tx_granted : in std_logic; -- indicates that access to channel has been granted
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mac_data_out_ready : in std_logic; -- indicates system ready to consume data
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mac_data_out_ready : in std_logic; -- indicates system ready to consume data
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mac_data_out_valid : out std_logic; -- indicates data out is valid
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mac_data_out_valid : out std_logic; -- indicates data out is valid
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mac_data_out_first : out std_logic; -- with data out valid indicates the first byte of a frame
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mac_data_out_last : out std_logic; -- with data out valid indicates the last byte of a frame
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mac_data_out_last : out std_logic; -- with data out valid indicates the last byte of a frame
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mac_data_out : out std_logic_vector (7 downto 0) -- ethernet frame (from dst mac addr through to last byte of frame)
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mac_data_out : out std_logic_vector (7 downto 0) -- ethernet frame (from dst mac addr through to last byte of frame)
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);
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);
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end IPv4_TX;
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end IPv4_TX;
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architecture Behavioral of IPv4_TX is
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architecture Behavioral of IPv4_TX is
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|
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type tx_state_type is (
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type tx_state_type is (
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IDLE,
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IDLE,
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WAIT_MAC, -- waiting for response from ARP for mac lookup
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WAIT_MAC, -- waiting for response from ARP for mac lookup
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WAIT_CHN, -- waiting for tx access to MAC channel
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WAIT_CHN, -- waiting for tx access to MAC channel
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SEND_ETH_HDR, -- sending the ethernet header
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SEND_ETH_HDR, -- sending the ethernet header
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SEND_IP_HDR, -- sending the IP header
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SEND_IP_HDR, -- sending the IP header
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SEND_USER_DATA -- sending the users data
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SEND_USER_DATA -- sending the users data
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);
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);
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type crc_state_type is (IDLE,TOT_LEN,ID,FLAGS,TTL,CKS,SAH,SAL,DAH,DAL,FINAL,WAIT_END);
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type crc_state_type is (IDLE,TOT_LEN,ID,FLAGS,TTL,CKS,SAH,SAL,DAH,DAL,FINAL,WAIT_END);
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|
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type count_mode_type is (RST, INCR, HOLD);
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type count_mode_type is (RST, INCR, HOLD);
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type settable_cnt_type is (RST, SET, INCR, HOLD);
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type settable_cnt_type is (RST, SET, INCR, HOLD);
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type set_clr_type is (SET, CLR, HOLD);
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type set_clr_type is (SET, CLR, HOLD);
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|
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-- Configuration
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-- Configuration
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|
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constant IP_TTL : std_logic_vector (7 downto 0) := x"80";
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constant IP_TTL : std_logic_vector (7 downto 0) := x"80";
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-- TX state variables
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-- TX state variables
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signal tx_state : tx_state_type;
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signal tx_state : tx_state_type;
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signal tx_count : unsigned (11 downto 0);
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signal tx_count : unsigned (11 downto 0);
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signal tx_result_reg : std_logic_vector (1 downto 0);
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signal tx_result_reg : std_logic_vector (1 downto 0);
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signal tx_mac : std_logic_vector (47 downto 0);
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signal tx_mac : std_logic_vector (47 downto 0);
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signal tx_mac_chn_reqd : std_logic;
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signal tx_mac_chn_reqd : std_logic;
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signal tx_hdr_cks : std_logic_vector (23 downto 0);
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signal tx_hdr_cks : std_logic_vector (23 downto 0);
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signal mac_lookup_req : std_logic;
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signal mac_lookup_req : std_logic;
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signal crc_state : crc_state_type;
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signal crc_state : crc_state_type;
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signal arp_req_ip_reg : std_logic_vector (31 downto 0);
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signal arp_req_ip_reg : std_logic_vector (31 downto 0);
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signal mac_data_out_ready_reg : std_logic;
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signal mac_data_out_ready_reg : std_logic;
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|
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-- tx control signals
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-- tx control signals
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signal next_tx_state : tx_state_type;
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signal next_tx_state : tx_state_type;
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signal set_tx_state : std_logic;
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signal set_tx_state : std_logic;
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signal next_tx_result : std_logic_vector (1 downto 0);
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signal next_tx_result : std_logic_vector (1 downto 0);
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signal set_tx_result : std_logic;
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signal set_tx_result : std_logic;
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signal set_tx_mac : std_logic;
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signal set_tx_mac : std_logic;
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signal tx_count_val : unsigned (11 downto 0);
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signal tx_count_val : unsigned (11 downto 0);
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signal tx_count_mode : settable_cnt_type;
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signal tx_count_mode : settable_cnt_type;
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signal tx_data : std_logic_vector (7 downto 0);
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signal tx_data : std_logic_vector (7 downto 0);
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signal set_last : std_logic;
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signal set_last : std_logic;
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signal set_chn_reqd : set_clr_type;
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signal set_chn_reqd : set_clr_type;
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signal set_mac_lku_req : set_clr_type;
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signal set_mac_lku_req : set_clr_type;
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signal tx_data_valid : std_logic; -- indicates whether data is valid to tx or not
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signal tx_data_valid : std_logic; -- indicates whether data is valid to tx or not
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-- tx temp signals
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-- tx temp signals
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signal total_length : std_logic_vector (15 downto 0); -- computed combinatorially from header size
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signal total_length : std_logic_vector (15 downto 0); -- computed combinatorially from header size
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FUNCTION inv_if_one(s1:std_logic_vector;en:std_logic) return std_logic_vector is
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FUNCTION inv_if_one(s1:std_logic_vector;en:std_logic) return std_logic_vector is
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--this function inverts all the bits of a vector if
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--this function inverts all the bits of a vector if
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--'en' is '1'.
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--'en' is '1'.
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VARIABLE Z : std_logic_vector(s1'high downto s1'low);
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VARIABLE Z : std_logic_vector(s1'high downto s1'low);
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BEGIN
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BEGIN
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FOR i IN (s1'low) to s1'high LOOP
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FOR i IN (s1'low) to s1'high LOOP
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Z(i) := en XOR s1(i);
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Z(i) := en XOR s1(i);
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END LOOP;
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END LOOP;
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RETURN Z;
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RETURN Z;
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END inv_if_one; -- end function
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END inv_if_one; -- end function
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|
|
|
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-- IP datagram header format
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-- IP datagram header format
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--
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--
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-- 0 4 8 16 19 24 31
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-- 0 4 8 16 19 24 31
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-- --------------------------------------------------------------------------------------------
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-- --------------------------------------------------------------------------------------------
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-- | Version | *Header | Service Type | Total Length including header |
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-- | Version | *Header | Service Type | Total Length including header |
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-- | (4) | Length | (ignored) | (in bytes) |
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-- | (4) | Length | (ignored) | (in bytes) |
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-- --------------------------------------------------------------------------------------------
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-- --------------------------------------------------------------------------------------------
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-- | Identification | Flags | Fragment Offset |
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-- | Identification | Flags | Fragment Offset |
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-- | | | (in 32 bit words) |
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-- | | | (in 32 bit words) |
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-- --------------------------------------------------------------------------------------------
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-- --------------------------------------------------------------------------------------------
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-- | Time To Live | Protocol | Header Checksum |
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-- | Time To Live | Protocol | Header Checksum |
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-- | (ignored) | | |
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-- | (ignored) | | |
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-- --------------------------------------------------------------------------------------------
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-- --------------------------------------------------------------------------------------------
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-- | Source IP Address |
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-- | Source IP Address |
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-- | |
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-- | |
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-- --------------------------------------------------------------------------------------------
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-- --------------------------------------------------------------------------------------------
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-- | Destination IP Address |
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-- | Destination IP Address |
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-- | |
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-- | |
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-- --------------------------------------------------------------------------------------------
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-- --------------------------------------------------------------------------------------------
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-- | Options (if any - ignored) | Padding |
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-- | Options (if any - ignored) | Padding |
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-- | | (if needed) |
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-- | | (if needed) |
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-- --------------------------------------------------------------------------------------------
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-- --------------------------------------------------------------------------------------------
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-- | Data |
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-- | Data |
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-- | |
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-- | |
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-- --------------------------------------------------------------------------------------------
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-- --------------------------------------------------------------------------------------------
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-- | .... |
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-- | .... |
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-- | |
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-- | |
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-- --------------------------------------------------------------------------------------------
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-- --------------------------------------------------------------------------------------------
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--
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--
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-- * - in 32 bit words
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-- * - in 32 bit words
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|
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begin
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begin
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-----------------------------------------------------------------------
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-----------------------------------------------------------------------
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-- combinatorial process to implement FSM and determine control signals
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-- combinatorial process to implement FSM and determine control signals
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-----------------------------------------------------------------------
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-----------------------------------------------------------------------
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tx_combinatorial : process(
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tx_combinatorial : process(
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-- input signals
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-- input signals
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ip_tx_start, ip_tx, clk, our_ip_address, our_mac_address, arp_req_rslt,
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ip_tx_start, ip_tx, clk, our_ip_address, our_mac_address, arp_req_rslt,
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mac_tx_granted, mac_data_out_ready,
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mac_tx_granted, mac_data_out_ready,
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-- state variables
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-- state variables
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tx_state, tx_count, tx_result_reg, tx_mac, tx_mac_chn_reqd,
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tx_state, tx_count, tx_result_reg, tx_mac, tx_mac_chn_reqd,
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mac_lookup_req, tx_hdr_cks, arp_req_ip_reg, mac_data_out_ready_reg,
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mac_lookup_req, tx_hdr_cks, arp_req_ip_reg, mac_data_out_ready_reg,
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-- control signals
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-- control signals
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next_tx_state, set_tx_state, next_tx_result, set_tx_result, set_tx_mac, tx_count_mode,
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next_tx_state, set_tx_state, next_tx_result, set_tx_result, set_tx_mac, tx_count_mode,
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tx_data, set_last, set_chn_reqd, set_mac_lku_req, total_length,
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tx_data, set_last, set_chn_reqd, set_mac_lku_req, total_length,
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tx_data_valid, tx_count_val
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tx_data_valid, tx_count_val
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)
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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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ip_tx_result <= tx_result_reg;
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ip_tx_result <= tx_result_reg;
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mac_tx_req <= tx_mac_chn_reqd;
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mac_tx_req <= tx_mac_chn_reqd;
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arp_req_req.lookup_req <= mac_lookup_req;
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arp_req_req.lookup_req <= mac_lookup_req;
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arp_req_req.ip <= arp_req_ip_reg;
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arp_req_req.ip <= arp_req_ip_reg;
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|
|
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-- set initial values for combinatorial outputs
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mac_data_out_first <= '0';
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|
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case tx_state is
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case tx_state is
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when SEND_ETH_HDR | SEND_IP_HDR =>
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when SEND_ETH_HDR | SEND_IP_HDR =>
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mac_data_out <= tx_data;
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mac_data_out <= tx_data;
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tx_data_valid <= mac_data_out_ready; -- generated internally
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tx_data_valid <= mac_data_out_ready; -- generated internally
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mac_data_out_last <= set_last;
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mac_data_out_last <= set_last;
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|
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when SEND_USER_DATA =>
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when SEND_USER_DATA =>
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mac_data_out <= ip_tx.data.data_out;
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mac_data_out <= ip_tx.data.data_out;
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tx_data_valid <= ip_tx.data.data_out_valid;
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tx_data_valid <= ip_tx.data.data_out_valid;
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mac_data_out_last <= ip_tx.data.data_out_last;
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mac_data_out_last <= ip_tx.data.data_out_last;
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|
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when others =>
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when others =>
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mac_data_out <= (others => '0');
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mac_data_out <= (others => '0');
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tx_data_valid <= '0'; -- not transmitting during this phase
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tx_data_valid <= '0'; -- not transmitting during this phase
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mac_data_out_last <= '0';
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mac_data_out_last <= '0';
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end case;
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end case;
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|
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mac_data_out_valid <= tx_data_valid and mac_data_out_ready;
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mac_data_out_valid <= tx_data_valid and mac_data_out_ready;
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|
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-- set signal defaults
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-- set signal defaults
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next_tx_state <= IDLE;
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next_tx_state <= IDLE;
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set_tx_state <= '0';
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set_tx_state <= '0';
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tx_count_mode <= HOLD;
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tx_count_mode <= HOLD;
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tx_data <= x"00";
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tx_data <= x"00";
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set_last <= '0';
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set_last <= '0';
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set_tx_mac <= '0';
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set_tx_mac <= '0';
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set_chn_reqd <= HOLD;
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set_chn_reqd <= HOLD;
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set_mac_lku_req <= HOLD;
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set_mac_lku_req <= HOLD;
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next_tx_result <= IPTX_RESULT_NONE;
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next_tx_result <= IPTX_RESULT_NONE;
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set_tx_result <= '0';
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set_tx_result <= '0';
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tx_count_val <= (others => '0');
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tx_count_val <= (others => '0');
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|
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-- set temp signals
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-- set temp signals
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total_length <= std_logic_vector(unsigned(ip_tx.hdr.data_length) + 20); -- total length = user data length + header length (bytes)
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total_length <= std_logic_vector(unsigned(ip_tx.hdr.data_length) + 20); -- total length = user data length + header length (bytes)
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|
|
-- TX FSM
|
-- TX FSM
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case tx_state is
|
case tx_state is
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when IDLE =>
|
when IDLE =>
|
ip_tx_data_out_ready <= '0'; -- in this state, we are unable to accept user data for tx
|
ip_tx_data_out_ready <= '0'; -- in this state, we are unable to accept user data for tx
|
tx_count_mode <= RST;
|
tx_count_mode <= RST;
|
set_chn_reqd <= CLR;
|
set_chn_reqd <= CLR;
|
if ip_tx_start = '1' then
|
if ip_tx_start = '1' then
|
-- check header count for error if too high
|
-- check header count for error if too high
|
if unsigned(ip_tx.hdr.data_length) > 1480 then
|
if unsigned(ip_tx.hdr.data_length) > 1480 then
|
next_tx_result <= IPTX_RESULT_ERR;
|
next_tx_result <= IPTX_RESULT_ERR;
|
set_tx_result <= '1';
|
set_tx_result <= '1';
|
else
|
else
|
-- TODO - check if we already have the mac addr for this ip, if so, bypass the WAIT_MAC state
|
-- TODO - check if we already have the mac addr for this ip, if so, bypass the WAIT_MAC state
|
|
|
-- req the mac address for this ip
|
-- req the mac address for this ip
|
set_mac_lku_req <= SET;
|
set_mac_lku_req <= SET;
|
next_tx_result <= IPTX_RESULT_SENDING;
|
next_tx_result <= IPTX_RESULT_SENDING;
|
set_tx_result <= '1';
|
set_tx_result <= '1';
|
next_tx_state <= WAIT_MAC;
|
next_tx_state <= WAIT_MAC;
|
set_tx_state <= '1';
|
set_tx_state <= '1';
|
end if;
|
end if;
|
else
|
else
|
set_mac_lku_req <= CLR;
|
set_mac_lku_req <= CLR;
|
end if;
|
end if;
|
|
|
when WAIT_MAC =>
|
when WAIT_MAC =>
|
ip_tx_data_out_ready <= '0'; -- in this state, we are unable to accept user data for tx
|
ip_tx_data_out_ready <= '0'; -- in this state, we are unable to accept user data for tx
|
if arp_req_rslt.got_mac = '1' then
|
if arp_req_rslt.got_mac = '1' then
|
-- save the MAC we got back from the ARP lookup
|
-- save the MAC we got back from the ARP lookup
|
set_tx_mac <= '1';
|
set_tx_mac <= '1';
|
set_chn_reqd <= SET;
|
set_chn_reqd <= SET;
|
set_mac_lku_req <= CLR;
|
set_mac_lku_req <= CLR;
|
-- check for optimise when already have the channel
|
-- check for optimise when already have the channel
|
if mac_tx_granted = '1' then
|
if mac_tx_granted = '1' then
|
-- ready to send data
|
-- ready to send data
|
next_tx_state <= SEND_ETH_HDR;
|
next_tx_state <= SEND_ETH_HDR;
|
set_tx_state <= '1';
|
set_tx_state <= '1';
|
else
|
else
|
next_tx_state <= WAIT_CHN;
|
next_tx_state <= WAIT_CHN;
|
set_tx_state <= '1';
|
set_tx_state <= '1';
|
end if;
|
end if;
|
elsif arp_req_rslt.got_err = '1' then
|
elsif arp_req_rslt.got_err = '1' then
|
set_mac_lku_req <= CLR;
|
set_mac_lku_req <= CLR;
|
next_tx_result <= IPTX_RESULT_ERR;
|
next_tx_result <= IPTX_RESULT_ERR;
|
set_tx_result <= '1';
|
set_tx_result <= '1';
|
next_tx_state <= IDLE;
|
next_tx_state <= IDLE;
|
set_tx_state <= '1';
|
set_tx_state <= '1';
|
end if;
|
end if;
|
|
|
when WAIT_CHN =>
|
when WAIT_CHN =>
|
ip_tx_data_out_ready <= '0'; -- in this state, we are unable to accept user data for tx
|
ip_tx_data_out_ready <= '0'; -- in this state, we are unable to accept user data for tx
|
if mac_tx_granted = '1' then
|
if mac_tx_granted = '1' then
|
-- ready to send data
|
-- ready to send data
|
next_tx_state <= SEND_ETH_HDR;
|
next_tx_state <= SEND_ETH_HDR;
|
set_tx_state <= '1';
|
set_tx_state <= '1';
|
end if;
|
end if;
|
-- probably should handle a timeout here
|
-- probably should handle a timeout here
|
|
|
when SEND_ETH_HDR =>
|
when SEND_ETH_HDR =>
|
ip_tx_data_out_ready <= '0'; -- in this state, we are unable to accept user data for tx
|
ip_tx_data_out_ready <= '0'; -- in this state, we are unable to accept user data for tx
|
if mac_data_out_ready = '1' then
|
if mac_data_out_ready = '1' then
|
if tx_count = x"00d" then
|
if tx_count = x"00d" then
|
tx_count_mode <= RST;
|
tx_count_mode <= RST;
|
next_tx_state <= SEND_IP_HDR;
|
next_tx_state <= SEND_IP_HDR;
|
set_tx_state <= '1';
|
set_tx_state <= '1';
|
else
|
else
|
tx_count_mode <= INCR;
|
tx_count_mode <= INCR;
|
end if;
|
end if;
|
case tx_count is
|
case tx_count is
|
when x"000" => tx_data <= tx_mac (47 downto 40); -- trg = mac from ARP lookup
|
when x"000" =>
|
|
mac_data_out_first <= mac_data_out_ready;
|
|
tx_data <= tx_mac (47 downto 40); -- trg = mac from ARP lookup
|
|
|
when x"001" => tx_data <= tx_mac (39 downto 32);
|
when x"001" => tx_data <= tx_mac (39 downto 32);
|
when x"002" => tx_data <= tx_mac (31 downto 24);
|
when x"002" => tx_data <= tx_mac (31 downto 24);
|
when x"003" => tx_data <= tx_mac (23 downto 16);
|
when x"003" => tx_data <= tx_mac (23 downto 16);
|
when x"004" => tx_data <= tx_mac (15 downto 8);
|
when x"004" => tx_data <= tx_mac (15 downto 8);
|
when x"005" => tx_data <= tx_mac (7 downto 0);
|
when x"005" => tx_data <= tx_mac (7 downto 0);
|
when x"006" => tx_data <= our_mac_address (47 downto 40); -- src = our mac
|
when x"006" => tx_data <= our_mac_address (47 downto 40); -- src = our mac
|
when x"007" => tx_data <= our_mac_address (39 downto 32);
|
when x"007" => tx_data <= our_mac_address (39 downto 32);
|
when x"008" => tx_data <= our_mac_address (31 downto 24);
|
when x"008" => tx_data <= our_mac_address (31 downto 24);
|
when x"009" => tx_data <= our_mac_address (23 downto 16);
|
when x"009" => tx_data <= our_mac_address (23 downto 16);
|
when x"00a" => tx_data <= our_mac_address (15 downto 8);
|
when x"00a" => tx_data <= our_mac_address (15 downto 8);
|
when x"00b" => tx_data <= our_mac_address (7 downto 0);
|
when x"00b" => tx_data <= our_mac_address (7 downto 0);
|
when x"00c" => tx_data <= x"08"; -- pkt type = 0800 : IP
|
when x"00c" => tx_data <= x"08"; -- pkt type = 0800 : IP
|
when x"00d" => tx_data <= x"00";
|
when x"00d" => tx_data <= x"00";
|
when others =>
|
when others =>
|
-- shouldnt get here - handle as error
|
-- shouldnt get here - handle as error
|
next_tx_result <= IPTX_RESULT_ERR;
|
next_tx_result <= IPTX_RESULT_ERR;
|
set_tx_result <= '1';
|
set_tx_result <= '1';
|
next_tx_state <= IDLE;
|
next_tx_state <= IDLE;
|
set_tx_state <= '1';
|
set_tx_state <= '1';
|
end case;
|
end case;
|
end if;
|
end if;
|
|
|
when SEND_IP_HDR =>
|
when SEND_IP_HDR =>
|
ip_tx_data_out_ready <= '0'; -- in this state, we are unable to accept user data for tx
|
ip_tx_data_out_ready <= '0'; -- in this state, we are unable to accept user data for tx
|
if mac_data_out_ready = '1' then
|
if mac_data_out_ready = '1' then
|
if tx_count = x"013" then
|
if tx_count = x"013" then
|
tx_count_val <= x"001";
|
tx_count_val <= x"001";
|
tx_count_mode <= SET;
|
tx_count_mode <= SET;
|
next_tx_state <= SEND_USER_DATA;
|
next_tx_state <= SEND_USER_DATA;
|
set_tx_state <= '1';
|
set_tx_state <= '1';
|
else
|
else
|
tx_count_mode <= INCR;
|
tx_count_mode <= INCR;
|
end if;
|
end if;
|
case tx_count is
|
case tx_count is
|
when x"000" => tx_data <= x"45"; -- v4, 5 words in hdr
|
when x"000" => tx_data <= x"45"; -- v4, 5 words in hdr
|
when x"001" => tx_data <= x"00"; -- service type
|
when x"001" => tx_data <= x"00"; -- service type
|
when x"002" => tx_data <= total_length (15 downto 8); -- total length
|
when x"002" => tx_data <= total_length (15 downto 8); -- total length
|
when x"003" => tx_data <= total_length (7 downto 0);
|
when x"003" => tx_data <= total_length (7 downto 0);
|
when x"004" => tx_data <= x"00"; -- identification
|
when x"004" => tx_data <= x"00"; -- identification
|
when x"005" => tx_data <= x"00";
|
when x"005" => tx_data <= x"00";
|
when x"006" => tx_data <= x"00"; -- flags and fragment offset
|
when x"006" => tx_data <= x"00"; -- flags and fragment offset
|
when x"007" => tx_data <= x"00";
|
when x"007" => tx_data <= x"00";
|
when x"008" => tx_data <= IP_TTL; -- TTL
|
when x"008" => tx_data <= IP_TTL; -- TTL
|
when x"009" => tx_data <= ip_tx.hdr.protocol; -- protocol
|
when x"009" => tx_data <= ip_tx.hdr.protocol; -- protocol
|
when x"00a" => tx_data <= tx_hdr_cks (15 downto 8); -- HDR checksum
|
when x"00a" => tx_data <= tx_hdr_cks (15 downto 8); -- HDR checksum
|
when x"00b" => tx_data <= tx_hdr_cks (7 downto 0); -- HDR checksum
|
when x"00b" => tx_data <= tx_hdr_cks (7 downto 0); -- HDR checksum
|
when x"00c" => tx_data <= our_ip_address (31 downto 24); -- src ip
|
when x"00c" => tx_data <= our_ip_address (31 downto 24); -- src ip
|
when x"00d" => tx_data <= our_ip_address (23 downto 16);
|
when x"00d" => tx_data <= our_ip_address (23 downto 16);
|
when x"00e" => tx_data <= our_ip_address (15 downto 8);
|
when x"00e" => tx_data <= our_ip_address (15 downto 8);
|
when x"00f" => tx_data <= our_ip_address (7 downto 0);
|
when x"00f" => tx_data <= our_ip_address (7 downto 0);
|
when x"010" => tx_data <= ip_tx.hdr.dst_ip_addr (31 downto 24); -- dst ip
|
when x"010" => tx_data <= ip_tx.hdr.dst_ip_addr (31 downto 24); -- dst ip
|
when x"011" => tx_data <= ip_tx.hdr.dst_ip_addr (23 downto 16);
|
when x"011" => tx_data <= ip_tx.hdr.dst_ip_addr (23 downto 16);
|
when x"012" => tx_data <= ip_tx.hdr.dst_ip_addr (15 downto 8);
|
when x"012" => tx_data <= ip_tx.hdr.dst_ip_addr (15 downto 8);
|
when x"013" => tx_data <= ip_tx.hdr.dst_ip_addr (7 downto 0);
|
when x"013" => tx_data <= ip_tx.hdr.dst_ip_addr (7 downto 0);
|
when others =>
|
when others =>
|
-- shouldnt get here - handle as error
|
-- shouldnt get here - handle as error
|
next_tx_result <= IPTX_RESULT_ERR;
|
next_tx_result <= IPTX_RESULT_ERR;
|
set_tx_result <= '1';
|
set_tx_result <= '1';
|
next_tx_state <= IDLE;
|
next_tx_state <= IDLE;
|
set_tx_state <= '1';
|
set_tx_state <= '1';
|
end case;
|
end case;
|
end if;
|
end if;
|
|
|
when SEND_USER_DATA =>
|
when SEND_USER_DATA =>
|
ip_tx_data_out_ready <= mac_data_out_ready and mac_data_out_ready_reg; -- in this state, we are always ready to accept user data for tx
|
ip_tx_data_out_ready <= mac_data_out_ready and mac_data_out_ready_reg; -- in this state, we are always ready to accept user data for tx
|
if mac_data_out_ready = '1' then
|
if mac_data_out_ready = '1' then
|
if ip_tx.data.data_out_valid = '1' or tx_count = x"000" then
|
if ip_tx.data.data_out_valid = '1' or tx_count = x"000" then
|
-- only increment if ready and valid has been subsequently established, otherwise data count moves on too fast
|
-- only increment if ready and valid has been subsequently established, otherwise data count moves on too fast
|
if unsigned(tx_count) = unsigned(ip_tx.hdr.data_length) then
|
if unsigned(tx_count) = unsigned(ip_tx.hdr.data_length) then
|
set_last <= '1';
|
set_last <= '1';
|
set_chn_reqd <= CLR;
|
set_chn_reqd <= CLR;
|
tx_data <= ip_tx.data.data_out;
|
tx_data <= ip_tx.data.data_out;
|
next_tx_result <= IPTX_RESULT_SENT;
|
next_tx_result <= IPTX_RESULT_SENT;
|
set_tx_result <= '1';
|
set_tx_result <= '1';
|
next_tx_state <= IDLE;
|
next_tx_state <= IDLE;
|
set_tx_state <= '1';
|
set_tx_state <= '1';
|
else
|
else
|
tx_count_mode <= INCR;
|
tx_count_mode <= INCR;
|
tx_data <= ip_tx.data.data_out;
|
tx_data <= ip_tx.data.data_out;
|
end if;
|
end if;
|
end if;
|
end if;
|
end if;
|
end if;
|
|
|
end case;
|
end case;
|
end process;
|
end process;
|
|
|
-----------------------------------------------------------------------------
|
-----------------------------------------------------------------------------
|
-- sequential process to action control signals and change states and outputs
|
-- sequential process to action control signals and change states and outputs
|
-----------------------------------------------------------------------------
|
-----------------------------------------------------------------------------
|
|
|
tx_sequential : process (clk,reset,mac_data_out_ready_reg)
|
tx_sequential : process (clk,reset,mac_data_out_ready_reg)
|
begin
|
begin
|
if rising_edge(clk) then
|
if rising_edge(clk) then
|
mac_data_out_ready_reg <= mac_data_out_ready;
|
mac_data_out_ready_reg <= mac_data_out_ready;
|
else
|
else
|
mac_data_out_ready_reg <= mac_data_out_ready_reg;
|
mac_data_out_ready_reg <= mac_data_out_ready_reg;
|
end if;
|
end if;
|
|
|
if rising_edge(clk) then
|
if rising_edge(clk) then
|
if reset = '1' then
|
if reset = '1' then
|
-- reset state variables
|
-- reset state variables
|
tx_state <= IDLE;
|
tx_state <= IDLE;
|
tx_count <= x"000";
|
tx_count <= x"000";
|
tx_result_reg <= IPTX_RESULT_NONE;
|
tx_result_reg <= IPTX_RESULT_NONE;
|
tx_mac <= (others => '0');
|
tx_mac <= (others => '0');
|
tx_mac_chn_reqd <= '0';
|
tx_mac_chn_reqd <= '0';
|
|
mac_lookup_req <= '0';
|
|
|
else
|
else
|
-- Next tx_state processing
|
-- Next tx_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 result processing
|
-- tx result processing
|
if set_tx_result = '1' then
|
if set_tx_result = '1' then
|
tx_result_reg <= next_tx_result;
|
tx_result_reg <= next_tx_result;
|
else
|
else
|
tx_result_reg <= tx_result_reg;
|
tx_result_reg <= tx_result_reg;
|
end if;
|
end if;
|
|
|
-- control arp lookup request
|
-- control arp lookup request
|
case set_mac_lku_req is
|
case set_mac_lku_req is
|
when SET =>
|
when SET =>
|
arp_req_ip_reg <= ip_tx.hdr.dst_ip_addr;
|
arp_req_ip_reg <= ip_tx.hdr.dst_ip_addr;
|
mac_lookup_req <= '1';
|
mac_lookup_req <= '1';
|
|
|
when CLR =>
|
when CLR =>
|
mac_lookup_req <= '0';
|
mac_lookup_req <= '0';
|
arp_req_ip_reg <= arp_req_ip_reg;
|
arp_req_ip_reg <= arp_req_ip_reg;
|
|
|
when HOLD =>
|
when HOLD =>
|
mac_lookup_req <= mac_lookup_req;
|
mac_lookup_req <= mac_lookup_req;
|
arp_req_ip_reg <= arp_req_ip_reg;
|
arp_req_ip_reg <= arp_req_ip_reg;
|
end case;
|
end case;
|
|
|
-- save MAC
|
-- save MAC
|
if set_tx_mac = '1' then
|
if set_tx_mac = '1' then
|
tx_mac <= arp_req_rslt.mac;
|
tx_mac <= arp_req_rslt.mac;
|
else
|
else
|
tx_mac <= tx_mac;
|
tx_mac <= tx_mac;
|
end if;
|
end if;
|
|
|
-- 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;
|
|
|
-- tx_count processing
|
-- tx_count processing
|
case tx_count_mode is
|
case tx_count_mode is
|
when RST => tx_count <= x"000";
|
when RST => tx_count <= x"000";
|
when SET => tx_count <= tx_count_val;
|
when SET => tx_count <= tx_count_val;
|
when INCR => tx_count <= tx_count + 1;
|
when INCR => tx_count <= tx_count + 1;
|
when HOLD => tx_count <= tx_count;
|
when HOLD => tx_count <= tx_count;
|
end case;
|
end case;
|
|
|
end if;
|
end if;
|
end if;
|
end if;
|
end process;
|
end process;
|
|
|
-----------------------------------------------------------------------------
|
-----------------------------------------------------------------------------
|
-- Process to calculate CRC in parallel with pkt out processing
|
-- Process to calculate CRC in parallel with pkt out processing
|
-- this process must yield a valid CRC before it is required to be used in the hdr
|
-- this process must yield a valid CRC before it is required to be used in the hdr
|
-----------------------------------------------------------------------------
|
-----------------------------------------------------------------------------
|
|
|
crc : process (clk,reset)
|
crc : process (clk,reset)
|
begin
|
begin
|
if rising_edge(clk) then
|
if rising_edge(clk) then
|
case crc_state is
|
case crc_state is
|
when IDLE =>
|
when IDLE =>
|
if ip_tx_start = '1' then
|
if ip_tx_start = '1' then
|
tx_hdr_cks <= x"004500"; -- vers & hdr len & service
|
tx_hdr_cks <= x"004500"; -- vers & hdr len & service
|
crc_state <= TOT_LEN;
|
crc_state <= TOT_LEN;
|
end if;
|
end if;
|
|
|
when TOT_LEN =>
|
when TOT_LEN =>
|
tx_hdr_cks <= std_logic_vector (unsigned(tx_hdr_cks) + unsigned(total_length));
|
tx_hdr_cks <= std_logic_vector (unsigned(tx_hdr_cks) + unsigned(total_length));
|
crc_state <= ID;
|
crc_state <= ID;
|
|
|
when ID =>
|
when ID =>
|
tx_hdr_cks <= tx_hdr_cks;
|
tx_hdr_cks <= tx_hdr_cks;
|
crc_state <= FLAGS;
|
crc_state <= FLAGS;
|
|
|
when FLAGS =>
|
when FLAGS =>
|
tx_hdr_cks <= tx_hdr_cks;
|
tx_hdr_cks <= tx_hdr_cks;
|
crc_state <= TTL;
|
crc_state <= TTL;
|
|
|
when TTL =>
|
when TTL =>
|
tx_hdr_cks <= std_logic_vector (unsigned(tx_hdr_cks) + unsigned(IP_TTL & ip_tx.hdr.protocol));
|
tx_hdr_cks <= std_logic_vector (unsigned(tx_hdr_cks) + unsigned(IP_TTL & ip_tx.hdr.protocol));
|
crc_state <= CKS;
|
crc_state <= CKS;
|
|
|
when CKS =>
|
when CKS =>
|
tx_hdr_cks <= tx_hdr_cks;
|
tx_hdr_cks <= tx_hdr_cks;
|
crc_state <= SAH;
|
crc_state <= SAH;
|
|
|
when SAH =>
|
when SAH =>
|
tx_hdr_cks <= std_logic_vector (unsigned(tx_hdr_cks) + unsigned(our_ip_address(31 downto 16)));
|
tx_hdr_cks <= std_logic_vector (unsigned(tx_hdr_cks) + unsigned(our_ip_address(31 downto 16)));
|
crc_state <= SAL;
|
crc_state <= SAL;
|
|
|
when SAL =>
|
when SAL =>
|
tx_hdr_cks <= std_logic_vector (unsigned(tx_hdr_cks) + unsigned(our_ip_address(15 downto 0)));
|
tx_hdr_cks <= std_logic_vector (unsigned(tx_hdr_cks) + unsigned(our_ip_address(15 downto 0)));
|
crc_state <= DAH;
|
crc_state <= DAH;
|
|
|
when DAH =>
|
when DAH =>
|
tx_hdr_cks <= std_logic_vector (unsigned(tx_hdr_cks) + unsigned(ip_tx.hdr.dst_ip_addr(31 downto 16)));
|
tx_hdr_cks <= std_logic_vector (unsigned(tx_hdr_cks) + unsigned(ip_tx.hdr.dst_ip_addr(31 downto 16)));
|
crc_state <= DAL;
|
crc_state <= DAL;
|
|
|
when DAL =>
|
when DAL =>
|
tx_hdr_cks <= std_logic_vector (unsigned(tx_hdr_cks) + unsigned(ip_tx.hdr.dst_ip_addr(15 downto 0)));
|
tx_hdr_cks <= std_logic_vector (unsigned(tx_hdr_cks) + unsigned(ip_tx.hdr.dst_ip_addr(15 downto 0)));
|
crc_state <= FINAL;
|
crc_state <= FINAL;
|
|
|
when FINAL =>
|
when FINAL =>
|
tx_hdr_cks <= inv_if_one(std_logic_vector (unsigned(tx_hdr_cks) + unsigned(tx_hdr_cks(23 downto 16))),'1');
|
tx_hdr_cks <= inv_if_one(std_logic_vector (unsigned(tx_hdr_cks) + unsigned(tx_hdr_cks(23 downto 16))),'1');
|
crc_state <= WAIT_END;
|
crc_state <= WAIT_END;
|
|
|
when WAIT_END =>
|
when WAIT_END =>
|
tx_hdr_cks <= tx_hdr_cks;
|
tx_hdr_cks <= tx_hdr_cks;
|
if ip_tx_start = '0' then
|
if ip_tx_start = '0' then
|
crc_state <= IDLE;
|
crc_state <= IDLE;
|
else
|
else
|
crc_state <= WAIT_END;
|
crc_state <= WAIT_END;
|
end if;
|
end if;
|
|
|
|
|
end case;
|
end case;
|
end if;
|
end if;
|
end process;
|
end process;
|
|
|
|
|
end Behavioral;
|
end Behavioral;
|
|
|
|
|
