diff options
Diffstat (limited to 'fpga/usrp2/udp/prot_eng_tx.v')
| -rw-r--r-- | fpga/usrp2/udp/prot_eng_tx.v | 166 |
1 files changed, 65 insertions, 101 deletions
diff --git a/fpga/usrp2/udp/prot_eng_tx.v b/fpga/usrp2/udp/prot_eng_tx.v index c642842f6..b4f6e55b8 100644 --- a/fpga/usrp2/udp/prot_eng_tx.v +++ b/fpga/usrp2/udp/prot_eng_tx.v @@ -1,146 +1,110 @@ -// The input FIFO contents should be 16 bits wide -// The first word is 1 for fast path (accelerated protocol) -// 0 for software implemented protocol -// The second word is the number of bytes in the packet, -// and must be valid even if we are in slow path mode -// Odd means the last word is half full -// Flags[1:0] is {eop, sop} -// Protocol word format is: -// 21 UDP Source Port Here -// 20 UDP Dest Port Here -// 19 Last Header Line -// 18 IP Header Checksum XOR -// 17 IP Length Here -// 16 UDP Length Here -// 15:0 data word to be sent - module prot_eng_tx #(parameter BASE=0) (input clk, input reset, input clear, input set_stb, input [7:0] set_addr, input [31:0] set_data, - input [18:0] datain, input src_rdy_i, output dst_rdy_o, - output [18:0] dataout, output src_rdy_o, input dst_rdy_i); - - wire [2:0] flags_i = datain[18:16]; - reg [15:0] dataout_int; - reg fast_path, sof_o; - - wire [2:0] flags_o = {flags_i[2], flags_i[1], sof_o}; // OCC, EOF, SOF + input [35:0] datain, input src_rdy_i, output dst_rdy_o, + output [35:0] dataout, output src_rdy_o, input dst_rdy_i); - assign dataout = {flags_o[2:0], dataout_int[15:0]}; + wire src_rdy_int1, dst_rdy_int1; + wire src_rdy_int2, dst_rdy_int2; + wire [35:0] data_int1, data_int2; - reg [4:0] state; - wire do_payload = (state == 31); - - assign dst_rdy_o = dst_rdy_i & (do_payload | (state==0) | (state==1) | (state==30)); - assign src_rdy_o = src_rdy_i & ~((state==0) | (state==1) | (state==30)); - - localparam HDR_WIDTH = 16 + 6; // 16 bits plus flags - localparam HDR_LEN = 32; // Up to 64 bytes of protocol + // Shortfifo on input to guarantee no deadlock + fifo_short #(.WIDTH(36)) head_fifo + (.clk(clk),.reset(reset),.clear(clear), + .datain(datain), .src_rdy_i(src_rdy_i), .dst_rdy_o(dst_rdy_o), + .dataout(data_int1), .src_rdy_o(src_rdy_int1), .dst_rdy_i(dst_rdy_int1), + .space(),.occupied() ); // Store header values in a small dual-port (distributed) ram - reg [HDR_WIDTH-1:0] header_ram[0:HDR_LEN-1]; - wire [HDR_WIDTH-1:0] header_word; - - reg [1:0] port_sel; - reg [31:0] per_port_data[0:3]; - reg [15:0] udp_src_port, udp_dst_port, chk_precompute; - - always @(posedge clk) udp_src_port <= per_port_data[port_sel][31:16]; - always @(posedge clk) udp_dst_port <= per_port_data[port_sel][15:0]; - + reg [31:0] header_ram[0:63]; + reg [3:0] state; + reg [1:0] port_sel; + always @(posedge clk) - if(set_stb & ((set_addr & 8'hE0) == BASE)) - header_ram[set_addr[4:0]] <= set_data; + if(set_stb & ((set_addr & 8'hC0) == BASE)) + header_ram[set_addr[5:0]] <= set_data; - always @(posedge clk) - if(set_stb & (set_addr == (BASE + 14))) - chk_precompute <= set_data[15:0]; + wire [31:0] header_word = header_ram[{port_sel[1:0],state[3:0]}]; + reg [15:0] pre_checksums [0:3]; always @(posedge clk) - if(set_stb & ((set_addr & 8'hFC) == (BASE+24))) - per_port_data[set_addr[1:0]] <= set_data; - - wire do_udp_src_port = header_word[21]; - wire do_udp_dst_port = header_word[20]; - wire last_hdr_line = header_word[19]; - wire do_ip_chk = header_word[18]; - wire do_ip_len = header_word[17]; - wire do_udp_len = header_word[16]; + if(set_stb & ((set_addr & 8'hCF)== (BASE+7))) + pre_checksums[set_addr[5:4]] <= set_data[15:0]; + + wire [15:0] pre_checksum = pre_checksums[port_sel[1:0]]; - assign header_word = header_ram[state]; - // Protocol State Machine reg [15:0] length; wire [15:0] ip_length = length + 28; // IP HDR + UDP HDR wire [15:0] udp_length = length + 8; // UDP HDR - + reg sof_o; + reg [31:0] prot_data; + always @(posedge clk) if(reset) begin - state <= 0; - fast_path <= 0; + state <= 0; sof_o <= 0; end else - if(src_rdy_i & dst_rdy_i) + if(src_rdy_int1 & dst_rdy_int2) case(state) 0 : begin - fast_path <= datain[0]; - port_sel <= datain[2:1]; - state <= 1; - end - 1 : - begin - length <= datain[15:0]; + port_sel <= data_int1[18:17]; + length <= data_int1[15:0]; sof_o <= 1; - if(fast_path) - state <= 2; + if(data_int1[16]) + state <= 1; else - state <= 30; // Skip 1 word for alignment + state <= 12; end - 30 : - state <= 31; - 31 : + 12 : begin sof_o <= 0; - if(flags_i[1]) // eop + if(data_int1[33]) // eof state <= 0; end default : begin sof_o <= 0; - if(~last_hdr_line) - state <= state + 1; - else - state <= 31; + state <= state + 1; end endcase // case (state) - wire [15:0] checksum; + wire [15:0] ip_checksum; add_onescomp #(.WIDTH(16)) add_onescomp - (.A(chk_precompute),.B(ip_length),.SUM(checksum)); - - reg [15:0] checksum_reg; - always @(posedge clk) - checksum_reg <= checksum; + (.A(pre_checksum),.B(ip_length),.SUM(ip_checksum)); + reg [15:0] ip_checksum_reg; + always @(posedge clk) ip_checksum_reg <= ip_checksum; always @* - if(do_payload) - dataout_int <= datain[15:0]; - else if(do_ip_chk) - dataout_int <= 16'hFFFF ^ checksum_reg; - else if(do_ip_len) - dataout_int <= ip_length; - else if(do_udp_len) - dataout_int <= udp_length; - else if(do_udp_src_port) - dataout_int <= udp_src_port; - else if(do_udp_dst_port) - dataout_int <= udp_dst_port; - else - dataout_int <= header_word[15:0]; + case(state) + 1 : prot_data <= header_word; // ETH, top half ignored + 2 : prot_data <= header_word; // ETH + 3 : prot_data <= header_word; // ETH + 4 : prot_data <= header_word; // ETH + 5 : prot_data <= { header_word[31:16], ip_length }; // IP + 6 : prot_data <= header_word; // IP + 7 : prot_data <= { header_word[31:16], (16'hFFFF ^ ip_checksum_reg) }; // IP + 8 : prot_data <= header_word; // IP + 9 : prot_data <= header_word; // IP + 10: prot_data <= header_word; // UDP + 11: prot_data <= { udp_length, header_word[15:0]}; // UDP + default : prot_data <= data_int1[31:0]; + endcase // case (state) + + assign data_int2 = { data_int1[35:33] & {3{state[3]}}, sof_o, prot_data }; + assign dst_rdy_int1 = dst_rdy_int2 & ((state == 0) | (state == 12)); + assign src_rdy_int2 = src_rdy_int1 & (state != 0); + + // Shortfifo on output to guarantee no deadlock + fifo_short #(.WIDTH(36)) tail_fifo + (.clk(clk),.reset(reset),.clear(clear), + .datain(data_int2), .src_rdy_i(src_rdy_int2), .dst_rdy_o(dst_rdy_int2), + .dataout(dataout), .src_rdy_o(src_rdy_o), .dst_rdy_i(dst_rdy_i), + .space(),.occupied() ); endmodule // prot_eng_tx |