Due to a problem in Quartus® Prime software version 17.0 and earlier, you may observe PCIe Signal Detect (SD) circuit unable to assert or switch “ON” at low temperature. Please check Cyclone® V Errata sheet for more details.
Device Family: Cyclone® V GT
Device Family: Cyclone® V ST
To work around this problem in Cyclone V GT and ST devices, make the following changes:
Add the following Quartus Prime Settings File (QSF) assignment for all PCI Express receiver channels in your design.
- set_instance_assignment -name XCVR_RX_COMMON_MODE_VOLTAGE VTT_0P70V -to <pin_name>
- set_instance_assignment -name XCVR_RX_SD_THRESHOLD 5 -to <pin_name>
Include the above assignment to all PCI Express receiver pins in the design and do not use wildcard characters (*) in the assignments.
However, Quartus Prime software version before 17.0 will not allow fitter compilation with the above QSF assignment. Hence, please contact MySupport for a patch.