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Add TCP calculator

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This commit is contained in:
Byron Lathi
2024-09-14 15:24:28 -07:00
parent fa80cab104
commit f742d9d89f
3 changed files with 73 additions and 4 deletions
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3
hw/super6502_fpga/src/sub/network_processor/sources.list
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@@ -18,4 +18,5 @@ src/eth_wrapper.sv
src/ip_arb_mux_wrapper.sv
src/ip_demux_wrapper.sv
src/tcp_dest_decap.sv
src/tcp_parser.sv
src/tcp_parser.sv
src/checksum_calc.sv

29
hw/super6502_fpga/src/sub/network_processor/src/checksum_calc.sv Normal file
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@@ -0,0 +1,29 @@
module checksum_calc (
input i_rst,
input i_clk,
input i_clear,
input i_enable,
input [31:0] i_data,
output [15:0] o_checksum
);
logic [31:0] sum;
logic [15:0] sum_wrapped;
assign sum_wrapped = sum[15:0] + sum [31:16];
assign o_checksum = ~sum_wrapped;
always @(posedge i_clk) begin
if (i_rst || i_clear) begin
sum <= '0;
end else begin
if (i_enable) begin
sum <= sum + i_data[31:16] + i_data[15:0];
end
end
end
endmodule

45
hw/super6502_fpga/src/sub/network_processor/src/tcp_packet_generator.sv
View File

@@ -24,14 +24,34 @@ module tcp_packet_generator (
logic [31:0] counter, counter_next;
enum logic [1:0] {IDLE, HEADER, DATA} state, state_next;
logic [15:0] checksum;
logic [31:0] checksum_counter, checksum_counter_next;
logic [15:0] data_checksum;
assign data_checksum = '0;
logic checksum_enable;
logic checksum_clear;
logic [31:0] checksum_data;
logic [15:0] checksum_final;
checksum_calc u_checksum_calc(
.i_rst (i_rst),
.i_clk (i_clk),
.i_clear (checksum_clear),
.i_enable (checksum_enable),
.i_data (checksum_data),
.o_checksum (checksum_final)
);
always_ff @(posedge i_clk) begin
if (i_rst) begin
counter <= '0;
checksum_counter <= '0;
state <= IDLE;
end else begin
counter <= counter_next;
checksum_counter <= checksum_counter_next;
state <= state_next;
end
end
@@ -41,11 +61,15 @@ always_comb begin
m_ip.ip_payload_axis_tvalid = '0;
m_ip.ip_payload_axis_tlast = '0;
o_packet_done = '0;
checksum_clear = '0;
checksum_enable = '0;
case (state)
IDLE: begin
counter_next = '0;
checksum_counter_next = '0;
checksum_clear = '1;
if (i_hdr_valid) begin
m_ip.ip_hdr_valid = '1;
@@ -65,6 +89,21 @@ always_comb begin
HEADER: begin
m_ip.ip_payload_axis_tvalid = '1;
if (checksum_counter < 8) begin
checksum_counter_next = checksum_counter + 1;
checksum_enable = '1;
end
case (checksum_counter)
0: checksum_data = m_ip.ip_source_ip;
1: checksum_data = m_ip.ip_dest_ip;
2: checksum_data = {8'b0, m_ip.ip_protocol, 16'd20}; // tcp length, not IP length
3: checksum_data = {i_source_port, i_dest_port};
4: checksum_data = i_seq_number;
5: checksum_data = i_ack_number;
6: checksum_data = {4'h5, 4'h0, i_flags, i_window_size};
7: checksum_data = '0; // checksum and urgent pointer
endcase
case (counter)
0: m_ip.ip_payload_axis_tdata = i_source_port[15:8];
@@ -83,8 +122,8 @@ always_comb begin
13: m_ip.ip_payload_axis_tdata = i_flags;
14: m_ip.ip_payload_axis_tdata = i_window_size[15:8];
15: m_ip.ip_payload_axis_tdata = i_window_size[7:0];
16: m_ip.ip_payload_axis_tdata = checksum[15:8];
17: m_ip.ip_payload_axis_tdata = checksum[7:0];
16: m_ip.ip_payload_axis_tdata = checksum_final[15:8];
17: m_ip.ip_payload_axis_tdata = checksum_final[7:0];
18: m_ip.ip_payload_axis_tdata = '0;
19: begin
m_ip.ip_payload_axis_tdata = '0;