Xilinx 1000BASE-X - Manual (Page 230)

230 www.xilinx.com Ethernet 1000BASE-X PCS/PMA or SGMII v9.1
UG155 March 24, 2008
Appendix F: Debugging Guide R
RocketIO Transceiver Specific Checks
Perform these additional checks when using a RocketIO transceiver:
•
Directly monitor the following ports of the RocketIO by attaching error counters to
them, or by triggering on them using Chipscope or an external logic analyzer.
RXDISPERR
RXNOTINTABLE
These signals should not be asserted over the duration of a few seconds, minutes or
even hours. If they are frequently asserted, it may indicate a problem with the
RocketIO. Consult
Answer Record 19699 for debugging RocketIO issues.
•
Place the RocketIO into parallel or serial loopback.
♦ If the core exhibits correct operation in RocketIO serial loopback, but not when
loopback is performed via an optical cable, it may indicate a faulty optical
module.
♦ If the core exhibits correct operation in RocketIO parallel loopback but not in
serial loopback, this may indicate a RocketIO problem. See
Answer Record 19699
for details.
•
A mild form of bit error rate may be solved by adjusting the transmitter
TX_PREEMPHASIS
, TX_DIFF_CTRL and TERMINATION_IMP attributes of the
RocketIO.
•
For Virtex-II Pro RocketIO only, check that the SERDES alignment logic is properly
constrained to be placed near the RocketIO. See the Virtex-II Pro RocketIO Transceiver
User Guide for more information. This constraint is not automatically adjusted for
different RocketIO locations.