The process of transferring a design from a supported device (Cyclone IV, MAX II, MAX V, Stratix IV, and Stratix V) family device to a different device in the same device family. You can transfer a design from the design's target device to a larger or smaller FineLine BGA device or to a larger or smaller device with equivalent pin-outs, while maintaining the same board layout and pin assignments. For example, if you want to transfer your project from a 484-pin FBGA package in a device family to another 672-pin FBGA package in the same device family, Altera recommends that, in devices with higher logic cell counts, you use I/O pins that are potential input pins as GND pins.
You specify migration devices for a device with the Migration Devices dialog box, which is available from the Device dialog box.
Device migration is also called "migration."