Why might the PCI Express signal detect feature fail at low temperatures on Arria® V GT and ST devices, and the link fails to train? - Why might the PCI Express signal detect feature fail at low temperatures on Arria® V GT and ST devices, and the link fails to train? Description Due to an incorrect receiver common mode voltage (Rx Vcm) setting in Quartus® II software version 14.0 and earlier, the PCI Express® signal detect feature may fail at low temperatures on Arria® V GT and ST devices, and the link fails to train. The table below shows the Arria® device VCCR_GXB and Rx Vcm requirements. Device VCCR_GXB Voltage Rx Vcm Voltage Arria V GX, SX 1.1V/1.15V 0.65V Arria V GT, ST 1.2V 0.75V Resolution To work around this problem in Arria® V GT and ST devices, you can download and install the patch below and add the following Quartus® II Settings File (QSF) assignment for all PCI Express receiver channels in your design. Download the Quartus II software version 13.1 patch 0.110 for Windows (.exe) Download the Quartus II software version 13.1 patch 0.110 for Linux (.run) Download the Quartus II software version 13.1 patch 0.110 Readme file (.txt) set_instance_assignment -name XCVR_RX_COMMON_MODE_VOLTAGE VTT_0P75V -to <pin_name> You must make the above assignment to all PCI Express receiver pins in your design, and you should not use wildcard characters (*) in your assignments. This problem has already been fixed in the Quartus® II software version 15.0. Custom Fields values: ['novalue'] Troubleshooting 245924 False ['Arria® V Transceiver Native PHY IP'] ['FPGA Dev Tools Quartus II Software'] 15.0 12.0.1 ['Arria® V FPGAs and SoCs', 'Arria® V GT FPGA', 'Arria® V ST FPGA'] ['novalue'] ['novalue'] ['novalue']