reimplemented mimo time transfer to handle 64 bits. Still needs

to sync on the received side.

5 files changed, 164 insertions, 71 deletions

diff --git a/usrp2/timing/time_64bit.v b/usrp2/timing/time_64bit.v
index 51c006962..1889e73da 100644
--- a/usrp2/timing/time_64bit.v
+++ b/usrp2/timing/time_64bit.v
@@ -3,12 +3,13 @@
 module time_64bit
   #(parameter TICKS_PER_SEC = 32'd100000000,
     parameter BASE = 0)
-    (input clk, input rst,
-     input set_stb, input [7:0] set_addr, input [31:0] set_data,  
-     input pps,
-     output [63:0] vita_time, output pps_int
-     );
-
+   (input clk, input rst,
+    input set_stb, input [7:0] set_addr, input [31:0] set_data,  
+    input pps,
+    output [63:0] vita_time, output pps_int,
+    input exp_time_in, output exp_time_out
+    );
+   
    localparam 	   NEXT_SECS = 0;   
    localparam 	   NEXT_TICKS = 1;
    localparam      PPS_POLSRC = 2;
@@ -91,5 +92,34 @@ module time_64bit
        ticks <= ticks_plus_one;
 
    assign pps_int = pps_edge;
+
+   localparam SYNC_RATE = 59999;   // Send every 600uS
+   reg [15:0] sync_counter;
+   wire       send_sync = (sync_counter == SYNC_RATE);
+   wire       sync_rcvd;
+   
+   always @(posedge clk)
+     if(rst)
+       sync_counter <= 0;
+     else
+       if(send_sync)
+	 sync_counter <= 0;
+       else
+	 sync_counter <= sync_counter + 1;
+   
+   // must be greater than 1000, 1 less than a multiple of 10;
+   
+   time_sender time_sender
+     (.clk(clk),.rst(rst),
+      .vita_time(vita_time),
+      .send_sync(send_sync),
+      .exp_pps_out(exp_pps_out) );
+
+   time_receiver time_receiver
+     (.clk(clk),.rst(rst),
+      .vita_time(vita_time_rcvd),
+      .sync_rcvd(sync_rcvd),
+      .exp_pps_in(exp_pps_in) );
+
    
 endmodule // time_64bit
diff --git a/usrp2/timing/time_receiver.v b/usrp2/timing/time_receiver.v
index 8e7d3f1ea..71f0ace90 100644
--- a/usrp2/timing/time_receiver.v
+++ b/usrp2/timing/time_receiver.v
@@ -1,9 +1,9 @@
 
 module time_receiver
   (input clk, input rst,
-   output [31:0] master_time,
+   output reg [63:0] vita_time,
    output sync_rcvd,
-   input exp_pps_in);
+   input exp_time_in);
 
    wire       code_err, disp_err, dispout, complete_word;
    reg 	      disp_reg;
@@ -13,7 +13,7 @@ module time_receiver
    reg [8:0]  dataout_reg;
  	      
    always @(posedge clk)
-     shiftreg <= {exp_pps_in, shiftreg[9:1]};
+     shiftreg <= {exp_time_in, shiftreg[9:1]};
 
    localparam COMMA_0 = 10'h283;
    localparam COMMA_1 = 10'h17c;
@@ -55,40 +55,72 @@ module time_receiver
    localparam STATE_T1 = 2;
    localparam STATE_T2 = 3;
    localparam STATE_T3 = 4;
+   localparam STATE_T4 = 5;
+   localparam STATE_T5 = 6;
+   localparam STATE_T6 = 7;
+   localparam STATE_T7 = 8;
+   localparam STATE_TAIL = 9;
    
    localparam HEAD = 9'h13c;   
-
-   reg [7:0]  clock_a, clock_b, clock_c;
-   reg [2:0]  state;
+   localparam TAIL = 9'h1F7;
+   
+   reg [3:0]  state;
    
    always @(posedge clk)
      if(rst)
        state <= STATE_IDLE;
      else if(complete_word)
-       case(state)
-	 STATE_IDLE :
-	   if(dataout_reg == HEAD)
-	     state <= STATE_T0;
-	 STATE_T0 :
-	   begin
-	      clock_a <= dataout_reg[7:0];
-	      state <= STATE_T1;
-	   end
-	 STATE_T1 :
-	   begin
-	      clock_b <= dataout_reg[7:0];
-	      state <= STATE_T2;
-	   end
-	 STATE_T2 :
-	   begin
-	      clock_c <= dataout_reg[7:0];
-	      state <= STATE_T3;
-	   end
-	 STATE_T3 :
-	   state <= STATE_IDLE;
-       endcase // case(state)
-
-   assign master_time =  {clock_a, clock_b, clock_c, dataout_reg[7:0]};
-   assign sync_rcvd = (complete_word & (state == STATE_T3));
-
+       if(code_err | disp_err)
+	 state <= STATE_IDLE;
+       else
+	 case(state)
+	   STATE_IDLE :
+	     if(dataout_reg == HEAD)
+	       state <= STATE_T0;
+	   STATE_T0 :
+	     begin
+		vita_time[63:56] <= dataout_reg[7:0];
+		state <= STATE_T1;
+	     end
+	   STATE_T1 :
+	     begin
+		vita_time[55:48] <= dataout_reg[7:0];
+		state <= STATE_T2;
+	     end
+	   STATE_T2 :
+	     begin
+		vita_time[47:40] <= dataout_reg[7:0];
+		state <= STATE_T3;
+	     end
+	   STATE_T3 :
+	     begin
+		vita_time[39:32] <= dataout_reg[7:0];
+		state <= STATE_T4;
+	     end
+	   STATE_T4 :
+	     begin
+		vita_time[31:24] <= dataout_reg[7:0];
+		state <= STATE_T5;
+	     end
+	   STATE_T5 :
+	     begin
+		vita_time[23:16] <= dataout_reg[7:0];
+		state <= STATE_T6;
+	     end
+	   STATE_T6 :
+	     begin
+		vita_time[15:8] <= dataout_reg[7:0];
+		state <= STATE_T7;
+	     end
+	   STATE_T7 :
+	     begin
+		vita_time[7:0] <= dataout_reg[7:0];
+		state <= STATE_TAIL;
+	     end
+	   STATE_TAIL :
+	     state <= STATE_IDLE;
+	 endcase // case(state)
+   
+   assign sync_rcvd = (complete_word & (state == STATE_TAIL) & (dataout_reg[8:0] == TAIL));
+   
 endmodule // time_sender
diff --git a/usrp2/timing/time_sender.v b/usrp2/timing/time_sender.v
index aa2fcbbdb..f4ee5226a 100644
--- a/usrp2/timing/time_sender.v
+++ b/usrp2/timing/time_sender.v
@@ -2,23 +2,23 @@
 
 module time_sender
   (input clk, input rst,
-   input [31:0] master_time,
+   input [63:0] vita_time,
    input send_sync,
-   output exp_pps_out);
+   output reg exp_time_out);
 
    reg [7:0] datain;
    reg 	     k;
    wire [9:0] dataout;
-   reg [9:0] dataout_reg;
-   reg 	     disp_reg;
-   wire      disp, new_word;
+   reg [9:0]  dataout_reg;
+   reg 	      disp_reg;
+   wire       disp, new_word;
+   reg [4:0]  state;
+   reg [3:0]  bit_count;
    
    encode_8b10b encode_8b10b 
      (.datain({k,datain}),.dispin(disp_reg),
       .dataout(dataout),.dispout(disp));
 
-   assign    exp_pps_out = dataout_reg[0];
-
    always @(posedge clk)
      if(rst)
        disp_reg <= 0;
@@ -33,9 +33,9 @@ module time_sender
      else
        dataout_reg <= {1'b0,dataout_reg[9:1]};
    
-   reg [4:0] state;
-   reg [3:0] bit_count;
-
+   always @(posedge clk)
+     exp_time_out <= dataout_reg[0];
+   
    assign    new_word = (bit_count == 9);
    
    always @(posedge clk)
@@ -52,17 +52,23 @@ module time_sender
    localparam SEND_T1 = 3;
    localparam SEND_T2 = 4;
    localparam SEND_T3 = 5;
+   localparam SEND_T4 = 6;
+   localparam SEND_T5 = 7;
+   localparam SEND_T6 = 8;
+   localparam SEND_T7 = 9;
+   localparam SEND_TAIL = 10;
 
    localparam COMMA = 8'hBC;
    localparam HEAD = 8'h3C;
-
-   reg [31:0] master_time_reg;
+   localparam TAIL = 8'hF7;
+   
+   reg [63:0] vita_time_reg;
    
    always @(posedge clk)
      if(rst)
-       master_time_reg <= 0;
+       vita_time_reg <= 0;
      else if(send_sync)
-       master_time_reg <= master_time;
+       vita_time_reg <= vita_time;
    
    always @(posedge clk)
      if(rst)
@@ -84,27 +90,51 @@ module time_sender
 	     end
 	   SEND_T0 :
 	     begin
-		{k,datain} <= {1'b0, master_time_reg[31:24] };
+		{k,datain} <= {1'b0, vita_time_reg[63:56] };
 		state <= SEND_T1;
 	     end
 	   SEND_T1 :
 	     begin
-		{k,datain} <= {1'b0, master_time_reg[23:16]};
+		{k,datain} <= {1'b0, vita_time_reg[55:48]};
 		state <= SEND_T2;
 	     end
 	   SEND_T2 :
 	     begin
-		{k,datain} <= {1'b0, master_time_reg[15:8]};
+		{k,datain} <= {1'b0, vita_time_reg[47:40]};
 		state <= SEND_T3;
 	     end
 	   SEND_T3 :
 	     begin
-		{k,datain} <= {1'b0, master_time_reg[7:0]};
+		{k,datain} <= {1'b0, vita_time_reg[39:32]};
+		state <= SEND_T4;
+	     end
+	   SEND_T4 :
+	     begin
+		{k,datain} <= {1'b0, vita_time_reg[31:24]};
+		state <= SEND_T5;
+	     end
+	   SEND_T5 :
+	     begin
+		{k,datain} <= {1'b0, vita_time_reg[23:16]};
+		state <= SEND_T6;
+	     end
+	   SEND_T6 :
+	     begin
+		{k,datain} <= {1'b0, vita_time_reg[15:8]};
+		state <= SEND_T7;
+	     end
+	   SEND_T7 :
+	     begin
+		{k,datain} <= {1'b0, vita_time_reg[7:0]};
+		state <= SEND_TAIL;
+	     end
+	   SEND_TAIL :
+	     begin
+		{k,datain} <= {1'b1, TAIL};
 		state <= SEND_IDLE;
 	     end
 	   default :
 	     state <= SEND_IDLE;
 	 endcase // case(state)
    
-   
 endmodule // time_sender
diff --git a/usrp2/timing/time_transfer_tb.v b/usrp2/timing/time_transfer_tb.v
index 2b75c60bd..0c164f82c 100644
--- a/usrp2/timing/time_transfer_tb.v
+++ b/usrp2/timing/time_transfer_tb.v
@@ -18,12 +18,12 @@ module time_transfer_tb();
    
    initial #100000000 $finish;
 
-   wire exp_pps, pps, pps_rcv;
-   wire [31:0] master_clock_rcv;
-   reg [31:0]  master_clock = 0;
-   reg [31:0]  counter = 0;
+   wire exp_time, pps, pps_rcv;
+   wire [63:0] vita_time_rcv;
+   reg [63:0]  vita_time = 0;
+   reg [63:0]  counter = 0;
 
-   localparam  PPS_PERIOD = 109;
+   localparam  PPS_PERIOD = 439; // PPS_PERIOD % 10 must = 9
    always @(posedge clk)
      if(counter == PPS_PERIOD)
        counter <= 0;
@@ -32,19 +32,19 @@ module time_transfer_tb();
    assign      pps = (counter == (PPS_PERIOD-1));
    
    always @(posedge clk)
-     master_clock <= master_clock + 1;
+     vita_time <= vita_time + 1;
    
    time_sender time_sender
      (.clk(clk),.rst(rst),
-      .master_clock(master_clock),
-      .pps(pps),
-      .exp_pps_out(exp_pps) );
+      .vita_time(vita_time),
+      .send_sync(pps),
+      .exp_time_out(exp_time) );
 
    time_receiver time_receiver
      (.clk(clk),.rst(rst),
-      .master_clock(master_clock_rcv),
-      .pps(pps_rcv),
-      .exp_pps_in(exp_pps) );
+      .vita_time(vita_time_rcv),
+      .sync_rcvd(pps_rcv),
+      .exp_time_in(exp_time) );
 
-   wire [31:0] delta = master_clock - master_clock_rcv;
+   wire [31:0] delta = vita_time - vita_time_rcv;
 endmodule // time_transfer_tb
diff --git a/usrp2/top/u2plus/u2plus_core.v b/usrp2/top/u2plus/u2plus_core.v
index bce38fc73..4e0b190ef 100644
--- a/usrp2/top/u2plus/u2plus_core.v
+++ b/usrp2/top/u2plus/u2plus_core.v
@@ -683,7 +683,8 @@ module u2plus_core
 
    time_64bit #(.TICKS_PER_SEC(32'd100000000),.BASE(SR_TIME64)) time_64bit
      (.clk(dsp_clk), .rst(dsp_rst), .set_stb(set_stb_dsp), .set_addr(set_addr_dsp), .set_data(set_data_dsp),
-      .pps(pps_in), .vita_time(vita_time), .pps_int(pps_int));
+      .pps(pps_in), .vita_time(vita_time), .pps_int(pps_int),
+      .exp_time_in(exp_time_in), .exp_time_out(exp_time_out));
    
    // /////////////////////////////////////////////////////////////////////////////////////////
    // Debug Pins