Calibration May Fail Without Issuing CAL_FAIL Signal

Description

This problem affects DDR2 and DDR3, QDR II, and RLDRAM II products..

For Stratix V devices using the Nios II-based sequencer, calibration may fail without asserting the CAL_FAIL signal, causing calibration to continue indefinitely.

Resolution

It is safe to assume that calibration has failed after five seconds of no response; in this circumstance, you may abort the calibration operation. This issue will be fixed in a future version of the external memory interface IP