1 files changed, 106 insertions, 0 deletions
diff --git a/fpga/usrp2/vrt/gen_context_pkt.v b/fpga/usrp2/vrt/gen_context_pkt.v
new file mode 100644
index 000000000..d6674e887
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+++ b/fpga/usrp2/vrt/gen_context_pkt.v
@@ -0,0 +1,106 @@
+//
+// Copyright 2011 Ettus Research LLC
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+
+
+module gen_context_pkt
+  #(parameter PROT_ENG_FLAGS=1,
+    parameter DSP_NUMBER=0)
+   (input clk, input reset, input clear,
+    input trigger, output sent,
+    input [31:0] streamid,
+    input [63:0] vita_time,
+    input [31:0] message,
+    input [31:0] seqnum,
+    output [35:0] data_o, output src_rdy_o, input dst_rdy_i);
+   
+   localparam CTXT_IDLE = 0;
+   localparam CTXT_PROT_ENG = 1;
+   localparam CTXT_HEADER = 2;
+   localparam CTXT_STREAMID = 3;
+   localparam CTXT_TICS = 4;
+   localparam CTXT_TICS2 = 5;
+   localparam CTXT_MESSAGE = 6;
+   localparam CTXT_FLOWCTRL = 7;
+   localparam CTXT_DONE = 8;
+
+   reg [33:0] 	 data_int;
+   wire 	 src_rdy_int, dst_rdy_int;
+   reg [3:0] 	 seqno;
+   reg [3:0] 	 ctxt_state;
+   reg [63:0] 	 err_time;
+   reg [31:0] 	 stored_message;
+   
+   always @(posedge clk)
+     if(reset | clear)
+       stored_message <= 0;
+     else
+       if(trigger)
+	 stored_message <= message;
+       else if(ctxt_state == CTXT_DONE)
+	 stored_message <= 0;
+
+   // Don't want to clear most of this to avoid getting stuck with a half packet in the pipe
+   always @(posedge clk)
+     if(reset)
+       begin
+	  ctxt_state <= CTXT_IDLE;
+	  seqno <= 0;
+       end
+     else
+       case(ctxt_state)
+	 CTXT_IDLE :
+	   if(trigger)
+	     begin
+		err_time <= vita_time;
+		if(PROT_ENG_FLAGS)
+		  ctxt_state <= CTXT_PROT_ENG;
+		else
+		  ctxt_state <= CTXT_HEADER;
+	     end
+	 
+	 CTXT_DONE :
+	   begin
+	      ctxt_state <= CTXT_IDLE;
+	      seqno <= seqno + 4'd1;
+	   end
+	 default :
+	   if(dst_rdy_int)
+	     ctxt_state <= ctxt_state + 1;
+       endcase // case (ctxt_state)
+
+   assign src_rdy_int = ~( (ctxt_state == CTXT_IDLE) | (ctxt_state == CTXT_DONE) );
+
+   always @*
+     case(ctxt_state)
+       CTXT_PROT_ENG : data_int <= { 2'b01, 13'b0, DSP_NUMBER[0], 1'b1, 1'b1, 16'd24 }; // UDP port 1 or 3
+       CTXT_HEADER : data_int <= { 1'b0, (PROT_ENG_FLAGS ? 1'b0 : 1'b1), 12'b010100000001, seqno, 16'd6 };
+       CTXT_STREAMID : data_int <= { 2'b00, streamid };
+       CTXT_TICS : data_int <= { 2'b00, err_time[63:32] };
+       CTXT_TICS2 : data_int <= { 2'b00, err_time[31:0] };
+       CTXT_MESSAGE : data_int <= { 2'b00, message };
+       CTXT_FLOWCTRL : data_int <= { 2'b10, seqnum };
+       default : data_int <= {2'b00, 32'b00};
+     endcase // case (ctxt_state)
+
+   fifo_short #(.WIDTH(34)) ctxt_fifo
+     (.clk(clk), .reset(reset), .clear(0),
+      .datain(data_int), .src_rdy_i(src_rdy_int), .dst_rdy_o(dst_rdy_int),
+      .dataout(data_o[33:0]), .src_rdy_o(src_rdy_o), .dst_rdy_i(dst_rdy_i));
+   assign data_o[35:34] = 2'b00;
+   
+endmodule // gen_context_pkt