Using PEX 8648 SMA Based (SI) Card White Paper – Version 1.3
© 2010 by PLX Technology, Inc. All Rights Reserved
14
10 Using External BERT (Analog Slave Loopback)
This mode allows the user to pre-configure the SI Card (Port 3) in slave analog loopback such that non-
PCIe compliant patterns (such as PRBS) can be injected via external means and then externally checked.
Figure 7. Configuration Drawing Example BERT application
Configuration of this mode can be done via EEPROM (example bin file included). Setup requires several
writes to the base register in Station 0 (Port 0) and a write to the Port 3 specific register. As a point of
clarity, note that Port 3 consists of SerDes numbers 12-15 (Port 3 Lane 0-3). These are the channels that
will be placed into loopback.
Programming Steps;
•
BERT (slave analog loopback)
o
Register 0204 – set SerDes 12-15 to Mask EIDLE (Fh)
o
Register 0234 – set Port 3 bits 23:20 to Port Quiet (8h)
o
Register 0234 – set Port 3 bits 27:24 for rate (8h)
o
Register 0BE4 – set value bits 31:0 to (80024745) SerDes overrides
System Box – CLK/PWR
BERT and System Offset /-300ppm
Ext
CLK
Ext
CLK
For Synchronous Operation, can reconfigure
PCB for external clocking. PCB CLKOUT feeds BERT
Detector.
