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wip: eth

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Markus Koch 2022-02-12 13:24:49 +01:00
parent 5c27b685dc
commit 6900a41528
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128
trashernet/trashernet_eth.vhd Normal file
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@ -0,0 +1,128 @@
-- -------------------------------------------------------------------------- --
-- TRASHERNET - A Trashy Ethernet Stack for FPGAs --
-- -------------------------------------------------------------------------- --
-- trashernet_mac_top.vhd : Ethernet OSI Layer 2, Data Link, filtered
-- Implements header creation, parsing, and protocol arbitration.
-- -------------------------------------------------------------------------- --
-- Author : Markus Koch <markus@notsyncing.net>
-- Contributors : None
-- License : Mozilla Public License (MPL) Version 2
-- -------------------------------------------------------------------------- --
library ieee;
use ieee.std_logic_1164.all;
use ieee.numeric_std.all;
use work.trashernet_pkg.all;
entity trashernet_eth is
generic(
F_CLK : in integer; -- Clock frequency of design IF
F_CLK_PHY : in integer; -- PHY clock (expected to be faster than F_CLK)
ETHERNET_II_PROTOCOLS : ethernet_ii_protocol_vector := ETHERNET_II_PROTOCOLS_NONE
);
port(
-- Global
clk : in std_logic; -- Global clock
rst : in std_logic; -- Asynchronous reset
-- MAC application interface
mac_out : in mac_out_t; -- MAC application IF (out of MAC)
mac_in : out mac_in_t; -- MAC application IF (into MAC)
-- Configuration
config : in configuration_t; -- Global Trashernet configuration
-- Ethernet 802.3 application interface
ethernet_i_out : out ethernet_i_out_t; -- Ethernet 802.3 IF (out from MAC)
ethernet_i_in : in ethernet_i_in_t := ETHERNET_I_IN_UNUSED; -- Ethernet 802.3 IF (out from MAC)
-- Ethernet II application interface
ethernet_ii_out : out ethernet_ii_out_vector(ETHERNET_II_PROTOCOLS'range); -- Ethernet II IF (out from MAC)
ethernet_ii_in : in ethernet_ii_in_vector(ETHERNET_II_PROTOCOLS'range) := (others => ETHERNET_II_IN_UNUSED) -- Ethernet II IF (into MAC)
);
end entity trashernet_eth;
architecture rtl of trashernet_eth is
begin
rx : block
signal sel : integer range ethernet_ii_out'low to ethernet_ii_out'high;
signal mac_destination_matches : std_logic;
begin
mac_destination_matches <= '1' when --
((mac_out.rx_header.mac_destination = (x"FF", x"FF")) or --
(mac_out.rx_header.mac_destination = config.mac_address)) else
'0';
mux : process(clk, rst) is
begin
if rst then
elsif rising_edge(clk) then
if mac_out.rx_mac_header_rcv then
if mac_destination_matches then
if (unsigned(std_logic_vector'(mac_out.rx_header.mac_ethertype(0) & mac_out.rx_header.mac_ethertype(1))) < 1500) then -- Ethernet 802.3 Frame
null; -- TODO: Not yet implemented
else -- Ethernet II Frame
for i in ETHERNET_II_PROTOCOLS'range loop
if (mac_out.rx_header.mac_ethertype = ETHERNET_II_PROTOCOLS(i).ethertype) then
sel <= i;
end if;
end loop;
end if;
end if;
end if;
end if;
end process mux;
-- Shared fields in the Ethernet application interface
shared_fields : for i in ethernet_ii_out'range generate
ethernet_ii_out(i).rx_mac_address <= mac_out.rx_header.mac_source;
ethernet_ii_out(i).rx_data <= mac_out.rx_mac_data;
ethernet_ii_out(i).rx_data_valid <= mac_out.rx_mac_valid when sel = i;
end generate shared_fields;
end block rx;
tx : block
type state_t is (IDLE, TXD);
signal state : state_t;
signal sel : integer range ethernet_ii_in'low to ethernet_ii_in'high;
begin
arb : process(clk, rst) is
begin
if rst then
elsif rising_edge(clk) then
case state is
when IDLE =>
if mac_out.tx_active then
for i in ethernet_ii_in'range loop
if ethernet_ii_in(i).tx_en then
sel <= i;
state <= TXD;
exit; -- Prioritize according to vector
end if;
end loop;
end if;
when TXD =>
state <= IDLE when (mac_in.tx_mac_data_en or mac_out.tx_active);
end case;
end if;
end process arb;
mac_in.tx_mac_data_en <= ethernet_ii_in(sel).tx_en;
mac_in.tx_mac_data <= ethernet_ii_in(sel).tx_data;
txack : for i in ethernet_ii_out'range generate
ethernet_ii_out(i).tx_data_ack <= mac_out.tx_mac_data_ack when sel = i else '0';
end generate txack;
mac_in.tx_header.mac_destination <= ethernet_ii_in(sel).tx_mac_address;
mac_in.tx_header.mac_ethertype <= ETHERNET_II_PROTOCOLS(sel).ethertype;
mac_in.tx_header.mac_source <= config.mac_address;
end block tx;
end architecture rtl;

34
trashernet/trashernet_pkg.vhd
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@ -29,6 +29,11 @@ package trashernet_pkg is
-- IP specific types -- IP specific types
subtype ip_addr_t is byte_vector(0 to 3); subtype ip_addr_t is byte_vector(0 to 3);
-- Configuration interface
type configuration_t is record
mac_address : mac_addr_t; -- MAC address of this node
end record configuration_t;
-- PHY interface -- PHY interface
type phy_in_t is record type phy_in_t is record
tx_data : byte; -- TX Data tx_data : byte; -- TX Data
@ -65,6 +70,35 @@ package trashernet_pkg is
rx_mac_crc_error : std_logic; -- End of packet, CRC invalid rx_mac_crc_error : std_logic; -- End of packet, CRC invalid
end record mac_out_t; end record mac_out_t;
-- MAC ETH interface
type ethernet_ii_protocol_t is record
ethertype : ethertype_t;
end record;
type ethernet_ii_protocol_vector is array (natural range <>) of ethernet_ii_protocol_t;
constant ETHERNET_II_PROTOCOLS_NONE : ethernet_ii_protocol_vector(0 to -1) := (others => (ethertype => (x"00", x"00"))); -- NULL range
type ethernet_i_out_t is record
tbd : std_logic; -- TODO
end record;
type ethernet_i_in_t is record
tbd : std_logic; -- TODO
end record;
constant ETHERNET_I_IN_UNUSED : ethernet_i_in_t := (others => '0'); -- TODO
type ethernet_ii_out_t is record
rx_mac_address : mac_addr_t; -- Source MAC address
rx_data : byte; -- RX data
rx_data_valid : std_logic; -- RX data valid strobe
tx_data_ack : std_logic; -- Give next data byte or disable `tx_en`
end record;
type ethernet_ii_in_t is record
tx_mac_address : mac_addr_t; -- Destination MAC address
tx_data : byte; -- TX data
tx_en : std_logic; -- Start and continue transmitting
end record;
type ethernet_ii_out_vector is array (natural range <>) of ethernet_ii_out_t;
type ethernet_ii_in_vector is array (natural range <>) of ethernet_ii_in_t;
constant ETHERNET_II_IN_UNUSED : ethernet_ii_in_t := (tx_mac_address => (others => x"00"), tx_data => x"00", others => '0');
end package trashernet_pkg; end package trashernet_pkg;
package body trashernet_pkg is package body trashernet_pkg is