Merge branch 'udp'

1 files changed, 23 insertions, 0 deletions

diff --git a/fpga/usrp2/timing/time_compare.v b/fpga/usrp2/timing/time_compare.v
new file mode 100644
index 000000000..a21c9f8e0
--- /dev/null
+++ b/fpga/usrp2/timing/time_compare.v
@@ -0,0 +1,23 @@
+
+// Top 32 bits are integer seconds, bottom 32 are clock ticks within a second
+
+module time_compare
+  (input [63:0] time_now,
+   input [63:0] trigger_time,
+   output now,
+   output early,
+   output late, 
+   output too_early);
+   
+   wire    sec_match   = (time_now[63:32] == trigger_time[63:32]);
+   wire    sec_late    = (time_now[63:32] > trigger_time[63:32]);
+
+   wire    tick_match  = (time_now[31:0] == trigger_time[31:0]);
+   wire    tick_late   = (time_now[31:0] > trigger_time[31:0]);
+   
+   assign now 	       = sec_match & tick_match;
+   assign late 	       = sec_late | (sec_match & tick_late);
+   assign early        = ~now & ~late;
+   assign too_early    = (trigger_time[63:32] > (time_now[63:32] + 4));  // Don't wait too long
+   
+endmodule // time_compare