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-rw-r--r--usrp2/timing/time_compare.v23
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+
+// 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