GRL-PCIE5-CEM-RXA User Guide and MOI
Rev7.0
© Granite River Labs 2022 Version 7.0, June 2022. Updated 06.29.2022
Page 106 of 123
10
Appendix C: Return Path Optimization Using MACOM
Technology Solutions Re-Driver
It is important to optimize the Return Path (DUT Tx to BERT Error Detector) when testing for
Receiver Link Equalization with PCIe Gen5 (32 GT/s), as described below.
10.1
Requirements for Using an External Driver (MACOM)
When testing the System Board, connect a MACOM Re-Driver between the DUT Tx and BERT Error
Detector. Refer to Section 10.3 for information on how to set up the MACOM Re-Driver.
Note
: While it is not necessary to use a Re-Driver for the Add-In Card Rx Link EQ Test, the same
method of optimizing the Return Path should apply when testing the System Board or Add-In Card.
10.2
Return Path Optimization Procedure
Follow the steps below to optimize the Return Path.
1.
Connect the equipment as shown in the System TxRx Link EQ Test setups in Section 5.5.1 &
5.6.1 or Section 8.2.2 & 8.3.2 respectively.
2.
Start the MX183000A, set the ‘Specification’ to ‘Gen5’, and then turn off all stresses
as follows:
•
SJ
•
RJ
•
DMI
•
CMI
3.
Select the
‘
LEQ Test Setting
’
checkbox in the MX183000A Main Window and set the following:
i)
Set
‘
PPG Starting Preset
’
to
‘
P5
’
ii)
Set
‘
DUT Initial Preset (Preset Hint Tx)
’
to
‘
P9
’
