Teledyne LeCroy Summit T3-16 PCIe Multi-lane Protocol Analyzer User Manual - Manual (Page 75)

Summit T3‐16 PCI Express Multi‐Lane Protocol Analyzer User Manual 63
Link Settings Teledyne LeCroy
Note: When selecting Auto in the Speed drop‐down list the embedded software is able to find the
correct speed even if the link does not go through a training sequence.
5.14.2 Link Width
The Link Width sets the physical width of the link. Select the Link Width from the drop‐
down menu (see
Figure 5.1 on page 54 : 3B).
Note: When selecting Auto in the Link Width drop‐down list the embedded software is able to find the
correct link width even if the link does not go through a training sequence.
5.14.3 Upstream and Downstream
Gives you low‐level control over each link direction. The heading for these boxes indicates
the port and/or unit to which the following options are applied based on the current
Analyzer configuration (see
Figure 5.1 on page 54 : 3C and 3D).
 Inhibit Channel: Do not record/upload this channel
 Reverse Lanes: Manual lane reversal. If Auto‐Configure Lane Swizzle is set, the
Reverse Lanes option will be ignored.
 Invert Polarity
5.14.4 Use External Reference Clock
If the PCI Express link under analysis uses spread‐spectrum clocking, then the Analyzer
must use the external reference clock from the system. If the Device Under Test does not
supply a reference clock, the internal reference clock in the Analyzer module can be used
instead (see
Figure 5.1 on page 54 : 3E). Only the standard PCIe reference clock is
supported.
5.14.5 Disable Descrambling
If checked, causes the Analyzer to assume that none of the PCI Express traffic is
scrambled. By default, the Analyzer determines the scrambling state of the devices under
test (see
Figure 5.1 on page 54 : 3F).
Note: When selecting Gen3 speed the disable scrambling option is not available. This option can be
used only for Gen1 or Gen2 speeds. It will show as well for Auto speed but it affects only Gen1 or
Gen2 traffic.
5.14.6 Auto-Configure Lane Polarity
Lets the Analyzer determine lane polarity (see Figure 5.1 on page 54 : 3G). Auto functions
such as Auto Configure polarity rely on Gen1 or Gen2 training sequences to properly
discover their values. If the speed option is set to fixed Gen3, the analyzer will never see
these sequences and the polarity discovery will not be reported properly in the
dashboard dialog.