Description:
The 'No Connect' (NC) pins of the MachXO2 packages are true NC, they are unbonded internally, the package pins/balls are floating, therefore the NC pins can be either left floating, connect to GND or VCC.
However, care must be taken on a device with NC if future pin migration is considered. On a lower density device with the same package, when moving to a higher density device, the pin could be used in that same package.
For instance, if a pin is a 'No Connect' in a smaller device and a VCCO in a larger device, the pin should be connected to VCCO to allow migration to the larger device.
Otherwise, if pin migration is not being considered in the future, or if the same pin is also NC on the devices in the family using this package, then the pin can be connected as needed.