Why do I see "VIOLATION ON DATAC" Vital timing violations in my Stratix device gate-level simulation for paths which are inactive?

Description

Due to a problem in the Quartus® II software,  gate-level simulation models for Stratix® and Stratix GX devices incorrectly allow transitioning signals to propagate through the ASDATA port of internal cells to the destination register even when the ASDATA signal is gated by an inactive SLOAD signal. This may result in timing violations in your gate-level simulation.

Resolution

To work around this problem, insert logic to synchronize the signal and avoid the timing violation.

This problem is fixed beginning with the Quartus II software version 12.0.