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DSOX4USBSQ USB 2.0 Signal Quality Analysis Application Electrical Testing Notes
3
Host Signal Quality Testing
Host Full Speed Signal Quality Test
To set up and run the Host Full Speed signal quality tests:
1
Connect the USB Device, test fixtures, and equipment. See
"Host Full
Speed Connection"
on page 48.
2
Set up the test signal/packet that will be analyzed.
To generate bus traffic, connect a known good Full Speed device to the
port under test and capture the Full Speed SOF to perform the eye
pattern analysis.
3
On the oscilloscope's front panel, press the
[Analyze]
key.
4
In the Analyze Menu, press the
Features
softkey; then, select
USB Signal
Quality
.
5
Press the
Test
softkey and select the
Host Full Speed Signal Quality
test.
6
Press the
Signals
softkey. In the USB Signal Quality Signals Menu:
a
Press the
D+ Source
softkey and select the analog input source
channel connected to the D+ signal (channel 2 in the previous
connection instructions).
b
Press the
D- Source
softkey and select the analog input source
channel connected to the D- signal (channel 3 in the previous
connection instructions).
On 4- channel oscilloscopes, you are forced to use different channel
pairs for the D+ and D- signals. This provides the maximum sample
rate. (Channels 1 and 2 are one pair and channels 3 and 4 are the
other pair.)
Table 7
Equipment Used in Host Downstream Full Speed Signal Quality Test
Quantity
Item
Description/Model
1
Oscilloscope
Agilent 4000 X-Series
2
Passive probes
Probes included with the oscilloscope are
sufficient.
1
Host test bed computer
Any computer with the Windows XP,
Windows 7, or Windows 8 operating system
and hi-speed USB ports.
1
SQiDD board
Agilent E2646A/B
1
full speed USB device
Intel Create and Share USB camera, P/N
735147-001, Model #: CS330
5
USB self-powered hubs
Any listed on USB-IF web site
6
5 meter USB cables
Any listed on USB-IF web site
