Teledyne LeCroy USBTracer_Trainer - Users Manual - Manual (Page 257)

USB Protocol Suite User Manual Chapter 10: Recording Options
LeCroy Corporation
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Analyzer mode (but not Exerciser mode) requires a clock to both the Clock-A-In
connector and the Clock-B-In connector on the front panel. The Clock-A-Out connector
outputs the identical signal that was supplied to the Clock-A-In connector. The
Clock-B-Out connector outputs the identical signal that was supplied to the Clock-B-In
connector. You can use Clock-A-Out and Clock-B-Out to pass through the actual DUT
onboard clock. If the Host DUT connects to port A, its Tx clock-out port should connect
to Clock-A-In. Then, the Clock-A-Out can connect to the Device DUT Rx clock-in port. On
the opposite side, the Device DUT Tx clock-out port should connect to Clock-B-In. Then
Clock-B-Out can connect to the Host DUT Rx clock-in port.
Note: The Clock Out feature is only supported on Voyager M3i.
If Voyager is in Host Emulation mode, connect the clock to the Clock-A-In connector. The
Exerciser uses this clock as its transmit clock and provides the identical output to the
Clock-A-Out connector.
If Voyager is in Device Emulation mode, connect the clock to the Clock-B-In connector.
Example setups using Voyager USB 3.0 in Exerciser Device Emulation mode over
SMA inputs with External Slow Clock option
The Exerciser uses this clock as its transmit clock and provides the identical output to the
Clock-B-Out connector. The analyzer scales down the timestamps in trace files to the
clocks in use, so a symbol remains a 2-ns entity regardless of the clocking frequency
value. All time values displayed in trace information reflect this scaled value, allowing
easy comparison with the USB 3.0 specification. If the DUT provides its own Tx clock,
you can connect the DUT clock to Clock In.
Note 1: LeCroy recommends using a LVPECL clock driver, which can drive a 50-ohm
load with a minimum peak-to-peak voltage swing of 200 mV. Maximum peak-to-peak
voltage swing should not exceed 1700 mV. Note that these voltages are single ended,
because only one of the differential signals is connected using the coaxial cable.