Xilinx LogiCORE IP Ethernet AVB Endpoint v2.4 User Manual page 168

Appendix A: RTC Time Stamp Accuracy
The maximum RTC inaccuracy, per time stamp sample, is equal to the period of the RTC
reference clock (in this example 40 ns). By using a high frequency RTC reference clock, a
high degree of accuracy can be obtained.
X-Ref Target - Figure A-1
168
RTC 0 40
40
0
-40
RTC Error (ns)
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80 120 160
80 120 160
Timestamp A
(Error = 39 ns)
Figure A-1: RTC Periodic Error
200 240
200 240
Timestamp B
(Error = 1 ns)
Ethernet AVB Endpoint User Guide
UG492 September 21, 2010
Time (ns)