When the device is not powered on or when the device is not configured, are the internal clamping diodes on Intel® Arria® V FPGA GPIO pins active?
Based on the Arria® V Device Handbook: Volume 1: Device Interfaces and Integration, the on-chip Clamping Diode feature is enabled and disabled through Intel® Quartus® Prime Software and limited to certain supported I/O standards.
For the unconfigured case, users cannot use the on-chip Clamping Diode feature. In other words, the on-chip Clamping Diodes are not applied to the GPIO pins when the device is not fully configured.