first cut at 64 bit time

git-svn-id: http://gnuradio.org/svn/gnuradio/trunk@10356 221aa14e-8319-0410-a670-987f0aec2ac5

diff --git a/usrp2/fpga/timing/time_64bit.v b/usrp2/fpga/timing/time_64bit.v
new file mode 100644 (file)
index 0000000..c0a846e
--- /dev/null
+++ b/usrp2/fpga/timing/time_64bit.v
@@ -0,0 +1,63 @@
+
+
+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
+     );
+
+   localparam     NEXT_TICKS = 0;
+   localparam     NEXT_SECS = 1;   
+   localparam     ROLLOVER = TICKS_PER_SEC - 1;           
+   
+   assign         vita_time = {seconds,ticks};
+   
+   wire [31:0]            next_ticks_preset;
+   wire [31:0]            next_seconds_preset;
+   wire           set_on_pps_trig;
+   reg                    set_on_next_pps;
+   
+   setting_reg #(.my_addr(BASE+NEXT_TICKS)) sr_next_ticks
+     (.clk(clk),.rst(rst),.strobe(set_stb),.addr(set_addr),
+      .in(set_data),.out(next_ticks_preset),.changed());
+   
+   setting_reg #(.my_addr(BASE+NEXT_SECS)) sr_next_secs
+     (.clk(clk),.rst(rst),.strobe(set_stb),.addr(set_addr),
+      .in(set_data),.out(next_seconds_preset),.changed(set_on_pps_trig));
+   
+   reg [31:0]     seconds;
+   reg [31:0]     ticks;
+   
+   wire           end_of_second;
+   
+   always @(posedge clk)
+     if(rst)
+       set_on_next_pps <= 0;
+     else if(set_on_pps_trig)
+       set_on_next_pps <= 1;
+     else if(pps)
+       set_on_next_pps <= 0;
+   
+   always @(posedge clk)
+     if(rst)
+       begin
+         seconds <= 32'd0;
+         ticks <= 32'd0;
+       end
+     else if(pps & set_on_next_pps)
+       begin
+         seconds <= next_seconds_preset;
+         ticks <= next_ticks_preset;
+       end
+     else if(ticks == ROLLOVER)
+       begin
+         seconds <= seconds + 1;
+         ticks <= 0;
+       end
+     else
+       ticks <= ticks + 1;
+   
+endmodule // time_64bit