Microchip Technology EVB-LAN9360, Руководство пользователя

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2021 Microchip Technology Inc. DS60001706A-page 29
4.6 1PPS METHOD FOR CLOCK ACCURACY MEASUREMENT
In this configuration the LAN9360 does not process audio data, neither as a Talker nor
as a Listener—hence, jumper settings are not required.
A one-pulse-per-second (1PPS) signal is provided at J9 to measure the accuracy of the
synchronization to the gPTP clock. The device may operate as gPTP master or gPTP
slave. Reception of a media clock is not required and has no influence on the 1PPS
signal.
Figure 4-6 indicates the location of J9 on the LAN9360 Development Board.
To evaluate the 1PPS signal, an oscilloscope can be connected to J9. However, the
most accurate measurement can be obtained by connecting the oscilloscope between
the mono flop and the resistor that goes to LAN9360 ball F8 (REFCLK0 signal), see
Figure A-1 .
It is of advantage to compare the 1PPS signals with multiple devices (gPTP master with
several gPTP slaves).
FIGURE 4-6: 1PPS METHOD FOR CLOCK ACCURACY MEASUREMENT – J9