Teledyne LeCroy QPHY-USB - Manual (Page 34)

34
QPHY-USB Operator’s Manual Rev F
Device or Hub High-Speed Suspend Resume Reset Timing
The Suspend Resume Reset test measures the timing of the Suspend Resume and Reset actions as well as the
operating voltage of the device. The voltage upon resuming high-speed operation should be between 360 mV and
440 mV. The voltage measurement is intended to verify entering High-Speed mode. The test conditions are not
optimal for measuring the resume voltage, and therefore it is possible for a compliant device to have a peak-to-
peak voltage slightly outside this range.
1. Select Device or Hub in the Mode control and HS Suspend Resume Reset in the Test control of the
USB Test Wizard.
2. Follow the instructions in the USB Test Wizard to acquire traces for suspend, resume, reset, and reset
from suspend functions. The traces should look like the following:
Figure 32. Time from Last Start of Frame to Device Suspend