Starting with the MIG v3.2 release, DDR3 multi-controller support is available. The Bank Selection page of the GUI only allows placement of data bytes belonging to the same controller within an FPGA bank. Is it possible to place data bytes from different DDR3 controllers in the same bank?
MIG v3.2-3.4 do not support sharing banks between any two controllers. Address/Control banks use too many pins to share with a separate controller. Data banks between controllers had specific architectural reasons pre MIG-3.4 which prohibited any data bank sharing across controllers. This dealt with the design usage of performance path clock outputs from the 2 MMCMs (system and read). Because the design, starting in MIG 3.4, only uses 1 MMCM per controller, it is possible to share data banks from two controllers in a single FPGA bank.
Sharing data banks between controllers is now supported starting in MIG v3.5.