Due to a problem in the Single Event Upset (SEU) diagnostic IP core from the Functional Safety Data Package, you may see this failure when you run the SEU test cycle continuously for a long time by periodically issuing the start command. You can detect this failure by observing “failc = 5: No error detected with bad CRC” in the control and status register.
This problem affects all device families (except Cyclone® IV, Cyclone III and Cyclone II) supported by the SEU diagnostic IP in all releases of the Functional Safety Data Package.
To work around this problem, check if “failc = 5” happens in the control and status register during the SEU test cycle and either reset the IP or issue the start command to restart the test cycle. Since the “failc = 5” failure is only related to the inability to inject an error during the test cycle and not a real SEU error in the circuit, it is safe to do a reset/restart . If the SEU IP then continues to run successfully the previous “failc = 5” error can be ignored. Note that other failure codes indicate real errors.
This problem is scheduled to be fixed in future release of the Functional Safety Data Package.