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AR# 50700

MIG 7 Series DDR3 - DQSFOUND calibration stage can go into an infinite loop


Version Found: v1.5
Version Resolved and other Known Issues: See (Xilinx Answer 45195).

During the DQSFOUND stage of calibration, the different DQS groups are aligned to the same PHY_Clk and the optimal read data offset position is found with respect to the read command. 

MIG 7 Series v1.5 has an issue where the DQSFOUND calibration stage can go into an infinite loop if the first iteration pass fails. 

If DQSFOUND calibration fails, calibration should stop and the pi_dqsfound_err signal should be asserted instead of going into an infinite loop.


DQSFOUND calibration will not go into an infinite loop for all interfaces, only where the DQSFOUND calibration stage should be failing due to problems in hardware.

For further details on the DQSFOUND calibration stage and hardware debugging steps, please refer to the Hardware Debug Guide found in (Xilinx Answer 43879).

AR# 50700
Date 08/13/2014
Status Active
Type Known Issues
  • Kintex-7
  • Virtex-7
  • MIG 7 Series
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