Xilinx IP Ethernet AVB Endpoint v2.4 UG492 - Manual (Page 168)

168 www.xilinx.com Ethernet AVB Endpoint User Guide
UG492 September 21, 2010
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
Figure A-1: RTC Periodic Error
Time (ns)
0
RTC Error (ns)
-40
40 80 120 160 200 240
Timestamp A
(Error = 39 ns) Timestamp B
(Error = 1 ns)
0 40 80 120 160 200 240 RTC