Teledyne LeCroy QPHY-USB3-Tx-Rx - Manual (Page 40)

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917719 Rev A
Deskew value in picoseconds
This variable allows the user to specify the channel + cable deskew between channels C1 and C2. The value is in
picoseconds and is applied to the channel C1. This value is only applied to C1 i f
“Us er Defined” is selected for the
Deskew measure mode variable.
PeRT3 Amplitude
This variable allows the user to control the amplitude of the PeRT3 during testing. The default for this variable is
0.8mV.
PeRT TX Init Mode
This variable controls the way the PeRT
3
configures the product under test to output test patterns. The choices
are “Loopback” or Low Frequency Periodic Signaling (“LFPS”). LFPS mode brings the Product under test into
Compliance Mode and outputs a Ping.LFPS signal to prompt the Product under test to switch to the next
compliance pattern. Loopback mode places the Product under test in Loopback Mode, and then outputs the
required Compliance Test Pattern. This mode does not produce valid compliance test results because the Product
under test outputs SKP symbols into the data. The recommended choice is
“LFPS” if it is supported.
Jitter & Eye Diagram Tests
The variables in this section allow the users to decide whether or not they would like the oscilloscope to perform
channel emulation and equalization as described by the specification. If yes, the user also has the ability to
specify the s-parameter file of the channel to emulate. Additionally the user can decide the location of the 2 poles,
the location of the zero and the DC gain for the continuous time linear equalizer (CTLE ). Finally, the Jitter Filter
Corner Frequency and Damping Factor that is used by SigTest can be set.
Common Mode Voltage Tests
The variable in this section allows the user to decide what pattern should be used to perform the A C and DC
common mode voltage tests. The default value for the variable is 0 which corresponds to the CP0 co mpliance
pattern. CP 1
– CP8 can also be selected.
Differential Voltage & De-emphasi s Test
The variables in this section allow the user to decide what pattern should be used to perform the Differential
Voltage & De-emphasis tests. The default value for the variable is the CP 7 compliance pattern for the Pattern wit h
de-emphasis and the CP8 compliance pattern for the pattern without de-emphasis. CP1
– CP8 can also be
selected. CP0 – CP8 can be selected for either variable.
Receiver Tests
Use Compliance Chanel
This variable allows the user to specify whether or not the compliance channel should be used during the receiver
tests. This variable is only used when the user is also using the RF S witch. Although use of the compliance
channel is required for receiver testing, this variable is useful when debugging problems . The default value for this
variable is
“Yes.”
Jitter Tolerance Test
The variables in this section allow the user to specify controls for running the Jitter Tolerance Test . The Symbol
Count variable specifies how many symbols should be tested during the jitter tolerance test . The default value for
this variable is
“3e10,” as required for compliance testing. The Frequency to Te st variable allows the user to
select “All” or any one particular complianc e test frequency for testing. The default value for this variable is “All.”
Also, the Compliance Test Pattern variable allows the user to specify which pattern to use for the jitter tolerance
test. The default value for this variable is
“CP0.”