Merge branch 'udp' into master_merge_take2

* udp: (67 commits)
  better test program for just the tx side
  fix typo, no functionality difference
  ignores
  move dsp settings regs to reclocked setting bus.  Works, gets us to within 18ps of passing timing
  reverting logic clean up which should have made timing better, but made it worse instead
  moved fifos around, now easier to see where they are and how big
  bigger fifo on UDP TX path, to possibly fix overruns on decim=4
  Xilinx ISE is incorrectly parsing the verilog case statement, this is a workaround
  pps and vita time debug pins
  ignore emacs backup files
  more debug for fixing E's
  better debug pins for going after cascading E's
  copy in wrong place
  copied over from quad radio
  just debug pin changes
  typo caused the tx udp chain to be disconnected
  moved into subdir
  speed up timing by ignoring the too_early error.  We'll need to FIXME this later
  Added set time and set time at next pps. Removed the old sync pps commands, they dont make sense to use anymore.
  moved around regs, added a bit to allow for alternate PPS source
  ...

1 files changed, 121 insertions, 0 deletions

diff --git a/usrp2/udp/prot_eng_rx.v b/usrp2/udp/prot_eng_rx.v
new file mode 100644
index 000000000..5df158b2b
--- /dev/null
+++ b/usrp2/udp/prot_eng_rx.v
@@ -0,0 +1,121 @@
+
+
+
+// Protocol Engine Receiver
+//  Checks each line (16 bits) against values in setting regs
+//  3 options for each line -- 
+//      Error if mismatch, Slowpath if mismatch, or ignore line
+//  The engine increases the length of each packet by 32 or 48 bits,
+//   bringing the total length to a multiple of 32 bits.  The last line
+//   is entirely new, and contains the results of the matching operation:
+//      16 bits of flags, 16 bits of data.  Flags indicate error or slowpath
+//      Data indicates line that caused mismatch if any.
+
+
+//   Flags[2:0] is {occ, eop, sop}
+//   Protocol word format is:
+//             22   Last Header Line
+//             21   SLOWPATH if mismatch
+//             20   ERROR if mismatch
+//             19   This is the IP checksum
+//             18   This is the UDP checksum
+//             17   Compute IP checksum on this word
+//             16   Compute UDP checksum on this word
+//           15:0   data word to be matched
+
+module prot_eng_rx
+  #(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);
+
+   localparam HDR_WIDTH  = 16 + 7;  // 16 bits plus flags
+   localparam HDR_LEN 	 = 32;      // Up to 64 bytes of protocol
+   
+   // 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;
+   
+   always @(posedge clk)
+     if(set_stb & ((set_addr & 8'hE0) == BASE))
+       header_ram[set_addr[4:0]] <= set_data;
+
+   assign header_word 	= header_ram[state];
+
+   wire consume_input 	= src_rdy_i & dst_rdy_o;
+   wire produce_output 	= src_rdy_o & dst_rdy_i;
+   
+   // Main State Machine
+   reg [15:0] pkt_length, fail_word, dataout_int;
+   
+   reg slowpath, error, sof_o, eof_o, occ_o, odd;
+
+   assign dataout    = {occ_o, eof_o, sof_o, dataout_int};
+
+   wire [15:0] calc_ip_checksum, calc_udp_checksum;
+   reg [15:0] rx_ip_checksum, rx_udp_checksum;
+
+   always @(posedge clk) 
+     if(header_word[19]) 
+       rx_ip_checksum  <= datain[15:0];
+   always @(posedge clk) 
+     if(header_word[18]) 
+       rx_udp_checksum <= datain[15:0];
+   
+   always @(posedge clk)
+     if(reset | clear)
+       begin
+	  slowpath     <= 0;
+	  error        <= 0;
+	  state        <= 0;
+	  fail_word    <= 0;
+	  eof_o        <= 0;
+	  occ_o        <= 0;
+       end
+     else if(src_rdy_i & dst_rdy_i)
+       case (state)
+	 0 :
+	   begin
+	      slowpath 	   <= 0;
+	      error 	   <= 0;
+	      eof_o 	   <= 0;
+	      occ_o 	   <= 0;
+	      state 	   <= 1;
+	   end
+
+	 ST_SLOWPATH :
+	   ;
+	 ST_ERROR :
+	   ;
+	 ST_PAYLOAD :
+	   ;
+	 ST_FILLER :
+	   ;
+	 ST_END1 :
+	   ;
+	 ST_END2 :
+	   ;
+	 default :
+	   if(header_word[21] && mismatch)
+	     state <= ST_SLOWPATH;
+	   else if(header_word[20] && mismatch)
+	     state <= ST_ERROR;
+	   else if(header_word[22])
+	     state <= ST_PAYLOAD;
+	   else
+	     state <= state + 1;
+       endcase // case (state)
+   
+
+
+   // IP + UDP checksum state machines
+   checksum_sm ip_chk
+     (.clk(clk), .reset(reset), .in(datain), 
+      .calc(consume_input & header_word[17]), .clear(state==0), .checksum(ip_checksum));
+   
+   checksum_sm udp_chk
+     (.clk(clk), .reset(reset), .in(datain), 
+      .calc(consume_input & header_word[16]), .clear(state==0), .checksum(udp_checksum));
+   
+endmodule // prot_eng_rx