mirror of
https://github.com/alexforencich/verilog-ethernet.git
synced 2025-01-14 06:43:18 +08:00
416 lines
15 KiB
Verilog
416 lines
15 KiB
Verilog
/*
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Copyright (c) 2014-2018 Alex Forencich
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Permission is hereby granted, free of charge, to any person obtaining a copy
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of this software and associated documentation files (the "Software"), to deal
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in the Software without restriction, including without limitation the rights
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to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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copies of the Software, and to permit persons to whom the Software is
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furnished to do so, subject to the following conditions:
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The above copyright notice and this permission notice shall be included in
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all copies or substantial portions of the Software.
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY
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FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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THE SOFTWARE.
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*/
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// Language: Verilog 2001
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`timescale 1ns / 1ps
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/*
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* AXI4-Stream ethernet frame receiver (AXI in, Ethernet frame out, 64 bit datapath)
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*/
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module eth_axis_rx_64
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(
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input wire clk,
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input wire rst,
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/*
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* AXI input
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*/
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input wire [63:0] s_axis_tdata,
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input wire [7:0] s_axis_tkeep,
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input wire s_axis_tvalid,
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output wire s_axis_tready,
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input wire s_axis_tlast,
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input wire s_axis_tuser,
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/*
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* Ethernet frame output
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*/
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output wire m_eth_hdr_valid,
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input wire m_eth_hdr_ready,
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output wire [47:0] m_eth_dest_mac,
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output wire [47:0] m_eth_src_mac,
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output wire [15:0] m_eth_type,
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output wire [63:0] m_eth_payload_axis_tdata,
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output wire [7:0] m_eth_payload_axis_tkeep,
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output wire m_eth_payload_axis_tvalid,
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input wire m_eth_payload_axis_tready,
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output wire m_eth_payload_axis_tlast,
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output wire m_eth_payload_axis_tuser,
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/*
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* Status signals
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*/
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output wire busy,
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output wire error_header_early_termination
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);
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/*
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Ethernet frame
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Field Length
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Destination MAC address 6 octets
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Source MAC address 6 octets
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Ethertype 2 octets
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This module receives an Ethernet frame on an AXI stream interface, decodes
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and strips the headers, then produces the header fields in parallel along
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with the payload in a separate AXI stream.
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*/
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localparam [2:0]
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STATE_IDLE = 3'd0,
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STATE_READ_HEADER = 3'd1,
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STATE_READ_PAYLOAD = 3'd2;
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reg [2:0] state_reg = STATE_IDLE, state_next;
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// datapath control signals
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reg store_hdr_word_0;
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reg store_hdr_word_1;
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reg flush_save;
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reg transfer_in_save;
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reg [7:0] frame_ptr_reg = 8'd0, frame_ptr_next;
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reg s_axis_tready_reg = 1'b0, s_axis_tready_next;
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reg m_eth_hdr_valid_reg = 1'b0, m_eth_hdr_valid_next;
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reg [47:0] m_eth_dest_mac_reg = 48'd0;
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reg [47:0] m_eth_src_mac_reg = 48'd0;
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reg [15:0] m_eth_type_reg = 16'd0;
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reg busy_reg = 1'b0;
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reg error_header_early_termination_reg = 1'b0, error_header_early_termination_next;
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reg [63:0] save_axis_tdata_reg = 64'd0;
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reg [7:0] save_axis_tkeep_reg = 8'd0;
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reg save_axis_tlast_reg = 1'b0;
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reg save_axis_tuser_reg = 1'b0;
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reg [63:0] shift_axis_tdata;
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reg [7:0] shift_axis_tkeep;
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reg shift_axis_tvalid;
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reg shift_axis_tlast;
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reg shift_axis_tuser;
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reg shift_axis_s_tready;
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reg shift_axis_extra_cycle;
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// internal datapath
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reg [63:0] m_eth_payload_axis_tdata_int;
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reg [7:0] m_eth_payload_axis_tkeep_int;
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reg m_eth_payload_axis_tvalid_int;
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reg m_eth_payload_axis_tready_int_reg = 1'b0;
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reg m_eth_payload_axis_tlast_int;
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reg m_eth_payload_axis_tuser_int;
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wire m_eth_payload_axis_tready_int_early;
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assign s_axis_tready = s_axis_tready_reg;
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assign m_eth_hdr_valid = m_eth_hdr_valid_reg;
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assign m_eth_dest_mac = m_eth_dest_mac_reg;
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assign m_eth_src_mac = m_eth_src_mac_reg;
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assign m_eth_type = m_eth_type_reg;
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assign busy = busy_reg;
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assign error_header_early_termination = error_header_early_termination_reg;
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always @* begin
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shift_axis_tdata[15:0] = save_axis_tdata_reg[63:48];
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shift_axis_tkeep[1:0] = save_axis_tkeep_reg[7:6];
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shift_axis_extra_cycle = save_axis_tlast_reg && (save_axis_tkeep_reg[7:6] != 0);
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if (shift_axis_extra_cycle) begin
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shift_axis_tdata[63:16] = 48'd0;
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shift_axis_tkeep[7:2] = 6'd0;
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shift_axis_tvalid = 1'b1;
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shift_axis_tlast = save_axis_tlast_reg;
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shift_axis_tuser = save_axis_tuser_reg;
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shift_axis_s_tready = flush_save;
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end else begin
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shift_axis_tdata[63:16] = s_axis_tdata[47:0];
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shift_axis_tkeep[7:2] = s_axis_tkeep[5:0];
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shift_axis_tvalid = s_axis_tvalid;
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shift_axis_tlast = (s_axis_tlast && (s_axis_tkeep[7:6] == 0));
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shift_axis_tuser = (s_axis_tuser && (s_axis_tkeep[7:6] == 0));
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shift_axis_s_tready = !(s_axis_tlast && s_axis_tvalid && transfer_in_save);
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end
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end
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always @* begin
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state_next = STATE_IDLE;
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s_axis_tready_next = 1'b0;
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flush_save = 1'b0;
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transfer_in_save = 1'b0;
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store_hdr_word_0 = 1'b0;
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store_hdr_word_1 = 1'b0;
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frame_ptr_next = frame_ptr_reg;
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m_eth_hdr_valid_next = m_eth_hdr_valid_reg && !m_eth_hdr_ready;
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error_header_early_termination_next = 1'b0;
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m_eth_payload_axis_tdata_int = 64'd0;
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m_eth_payload_axis_tkeep_int = 8'd0;
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m_eth_payload_axis_tvalid_int = 1'b0;
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m_eth_payload_axis_tlast_int = 1'b0;
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m_eth_payload_axis_tuser_int = 1'b0;
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case (state_reg)
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STATE_IDLE: begin
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// idle state - wait for data
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frame_ptr_next = 8'd0;
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flush_save = 1'b1;
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s_axis_tready_next = !m_eth_hdr_valid_reg;
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if (s_axis_tready && s_axis_tvalid) begin
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// got first word of packet
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if (s_axis_tlast) begin
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// tlast asserted on first word
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error_header_early_termination_next = 1'b1;
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state_next = STATE_IDLE;
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end else begin
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// move to read header state
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frame_ptr_next = 8'd8;
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store_hdr_word_0 = 1'b1;
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transfer_in_save = 1'b1;
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state_next = STATE_READ_HEADER;
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end
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end else begin
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state_next = STATE_IDLE;
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end
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end
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STATE_READ_HEADER: begin
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// read header state
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s_axis_tready_next = 1'b1;
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if (s_axis_tready && s_axis_tvalid) begin
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// word transfer in - store it
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frame_ptr_next = frame_ptr_reg + 8'd8;
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transfer_in_save = 1'b1;
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state_next = STATE_READ_HEADER;
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case (frame_ptr_reg)
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8'h00: store_hdr_word_0 = 1'b1;
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8'h08: begin
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store_hdr_word_1 = 1'b1;
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m_eth_hdr_valid_next = 1'b1;
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s_axis_tready_next = m_eth_payload_axis_tready_int_early;
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state_next = STATE_READ_PAYLOAD;
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end
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endcase
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if (s_axis_tlast) begin
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if (s_axis_tkeep[7:6] != 2'd0) begin
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s_axis_tready_next = 1'b0;
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state_next = STATE_READ_PAYLOAD;
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end else begin
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flush_save = 1'b1;
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m_eth_hdr_valid_next = 1'b0;
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error_header_early_termination_next = 1'b1;
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s_axis_tready_next = !m_eth_hdr_valid_reg;
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state_next = STATE_IDLE;
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end
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end
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end else begin
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state_next = STATE_READ_HEADER;
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end
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end
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STATE_READ_PAYLOAD: begin
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// read payload
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s_axis_tready_next = m_eth_payload_axis_tready_int_early && shift_axis_s_tready;
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m_eth_payload_axis_tdata_int = shift_axis_tdata;
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m_eth_payload_axis_tkeep_int = shift_axis_tkeep;
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m_eth_payload_axis_tvalid_int = shift_axis_tvalid;
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m_eth_payload_axis_tlast_int = shift_axis_tlast;
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m_eth_payload_axis_tuser_int = shift_axis_tuser;
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if (m_eth_payload_axis_tready_int_reg && shift_axis_tvalid) begin
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// word transfer through
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transfer_in_save = 1'b1;
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if (shift_axis_tlast) begin
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flush_save = 1'b1;
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s_axis_tready_next = !m_eth_hdr_valid_reg;
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state_next = STATE_IDLE;
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end else begin
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state_next = STATE_READ_PAYLOAD;
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end
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end else begin
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state_next = STATE_READ_PAYLOAD;
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end
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end
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endcase
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end
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always @(posedge clk) begin
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if (rst) begin
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state_reg <= STATE_IDLE;
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frame_ptr_reg <= 8'd0;
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s_axis_tready_reg <= 1'b0;
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m_eth_hdr_valid_reg <= 1'b0;
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save_axis_tlast_reg <= 1'b0;
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busy_reg <= 1'b0;
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error_header_early_termination_reg <= 1'b0;
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end else begin
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state_reg <= state_next;
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frame_ptr_reg <= frame_ptr_next;
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s_axis_tready_reg <= s_axis_tready_next;
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m_eth_hdr_valid_reg <= m_eth_hdr_valid_next;
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error_header_early_termination_reg <= error_header_early_termination_next;
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busy_reg <= state_next != STATE_IDLE;
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if (flush_save) begin
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save_axis_tlast_reg <= 1'b0;
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end else if (transfer_in_save) begin
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save_axis_tlast_reg <= s_axis_tlast;
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end
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end
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// datapath
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if (store_hdr_word_0) begin
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m_eth_dest_mac_reg[47:40] <= s_axis_tdata[ 7: 0];
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m_eth_dest_mac_reg[39:32] <= s_axis_tdata[15: 8];
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m_eth_dest_mac_reg[31:24] <= s_axis_tdata[23:16];
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m_eth_dest_mac_reg[23:16] <= s_axis_tdata[31:24];
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m_eth_dest_mac_reg[15: 8] <= s_axis_tdata[39:32];
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m_eth_dest_mac_reg[ 7: 0] <= s_axis_tdata[47:40];
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m_eth_src_mac_reg[47:40] <= s_axis_tdata[55:48];
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m_eth_src_mac_reg[39:32] <= s_axis_tdata[63:56];
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end
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if (store_hdr_word_1) begin
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m_eth_src_mac_reg[31:24] <= s_axis_tdata[ 7: 0];
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m_eth_src_mac_reg[23:16] <= s_axis_tdata[15: 8];
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m_eth_src_mac_reg[15: 8] <= s_axis_tdata[23:16];
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m_eth_src_mac_reg[ 7: 0] <= s_axis_tdata[31:24];
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m_eth_type_reg[15:8] <= s_axis_tdata[39:32];
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m_eth_type_reg[ 7:0] <= s_axis_tdata[47:40];
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end
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if (transfer_in_save) begin
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save_axis_tdata_reg <= s_axis_tdata;
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save_axis_tkeep_reg <= s_axis_tkeep;
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save_axis_tuser_reg <= s_axis_tuser;
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end
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end
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// output datapath logic
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reg [64:0] m_eth_payload_axis_tdata_reg = 64'd0;
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reg [7:0] m_eth_payload_axis_tkeep_reg = 8'd0;
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reg m_eth_payload_axis_tvalid_reg = 1'b0, m_eth_payload_axis_tvalid_next;
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reg m_eth_payload_axis_tlast_reg = 1'b0;
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reg m_eth_payload_axis_tuser_reg = 1'b0;
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reg [64:0] temp_m_eth_payload_axis_tdata_reg = 64'd0;
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reg [7:0] temp_m_eth_payload_axis_tkeep_reg = 8'd0;
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reg temp_m_eth_payload_axis_tvalid_reg = 1'b0, temp_m_eth_payload_axis_tvalid_next;
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reg temp_m_eth_payload_axis_tlast_reg = 1'b0;
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reg temp_m_eth_payload_axis_tuser_reg = 1'b0;
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// datapath control
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reg store_eth_payload_int_to_output;
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reg store_eth_payload_int_to_temp;
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reg store_eth_payload_axis_temp_to_output;
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assign m_eth_payload_axis_tdata = m_eth_payload_axis_tdata_reg;
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assign m_eth_payload_axis_tkeep = m_eth_payload_axis_tkeep_reg;
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assign m_eth_payload_axis_tvalid = m_eth_payload_axis_tvalid_reg;
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assign m_eth_payload_axis_tlast = m_eth_payload_axis_tlast_reg;
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assign m_eth_payload_axis_tuser = m_eth_payload_axis_tuser_reg;
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// enable ready input next cycle if output is ready or the temp reg will not be filled on the next cycle (output reg empty or no input)
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assign m_eth_payload_axis_tready_int_early = m_eth_payload_axis_tready || (!temp_m_eth_payload_axis_tvalid_reg && (!m_eth_payload_axis_tvalid_reg || !m_eth_payload_axis_tvalid_int));
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always @* begin
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// transfer sink ready state to source
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m_eth_payload_axis_tvalid_next = m_eth_payload_axis_tvalid_reg;
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temp_m_eth_payload_axis_tvalid_next = temp_m_eth_payload_axis_tvalid_reg;
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store_eth_payload_int_to_output = 1'b0;
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store_eth_payload_int_to_temp = 1'b0;
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store_eth_payload_axis_temp_to_output = 1'b0;
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if (m_eth_payload_axis_tready_int_reg) begin
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// input is ready
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if (m_eth_payload_axis_tready || !m_eth_payload_axis_tvalid_reg) begin
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// output is ready or currently not valid, transfer data to output
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m_eth_payload_axis_tvalid_next = m_eth_payload_axis_tvalid_int;
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store_eth_payload_int_to_output = 1'b1;
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end else begin
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// output is not ready, store input in temp
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temp_m_eth_payload_axis_tvalid_next = m_eth_payload_axis_tvalid_int;
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store_eth_payload_int_to_temp = 1'b1;
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end
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end else if (m_eth_payload_axis_tready) begin
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// input is not ready, but output is ready
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m_eth_payload_axis_tvalid_next = temp_m_eth_payload_axis_tvalid_reg;
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temp_m_eth_payload_axis_tvalid_next = 1'b0;
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store_eth_payload_axis_temp_to_output = 1'b1;
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end
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end
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always @(posedge clk) begin
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if (rst) begin
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m_eth_payload_axis_tvalid_reg <= 1'b0;
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m_eth_payload_axis_tready_int_reg <= 1'b0;
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temp_m_eth_payload_axis_tvalid_reg <= 1'b0;
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end else begin
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m_eth_payload_axis_tvalid_reg <= m_eth_payload_axis_tvalid_next;
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m_eth_payload_axis_tready_int_reg <= m_eth_payload_axis_tready_int_early;
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temp_m_eth_payload_axis_tvalid_reg <= temp_m_eth_payload_axis_tvalid_next;
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end
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// datapath
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if (store_eth_payload_int_to_output) begin
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m_eth_payload_axis_tdata_reg <= m_eth_payload_axis_tdata_int;
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m_eth_payload_axis_tkeep_reg <= m_eth_payload_axis_tkeep_int;
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m_eth_payload_axis_tlast_reg <= m_eth_payload_axis_tlast_int;
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m_eth_payload_axis_tuser_reg <= m_eth_payload_axis_tuser_int;
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end else if (store_eth_payload_axis_temp_to_output) begin
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m_eth_payload_axis_tdata_reg <= temp_m_eth_payload_axis_tdata_reg;
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m_eth_payload_axis_tkeep_reg <= temp_m_eth_payload_axis_tkeep_reg;
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m_eth_payload_axis_tlast_reg <= temp_m_eth_payload_axis_tlast_reg;
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m_eth_payload_axis_tuser_reg <= temp_m_eth_payload_axis_tuser_reg;
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end
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if (store_eth_payload_int_to_temp) begin
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temp_m_eth_payload_axis_tdata_reg <= m_eth_payload_axis_tdata_int;
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temp_m_eth_payload_axis_tkeep_reg <= m_eth_payload_axis_tkeep_int;
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temp_m_eth_payload_axis_tlast_reg <= m_eth_payload_axis_tlast_int;
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temp_m_eth_payload_axis_tuser_reg <= m_eth_payload_axis_tuser_int;
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end
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end
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endmodule
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