The MIG RLDRAM3 design uses 20 address bits regardless of the Burst Length selected. Therefore, it is possible for the user to try and write/read to an address location that does not exist.
For RLDRAM3 memory, the address width varies based on the burst length. The MIG RLDRAM3 design will always use 20 address bits regardless of the burst length, so you must be aware of this and avoid accessing memory locations that do not exist. Refer to the RLDRAM3 data sheet for address width configurations based off different burst lengths.
Following is an example of the address width configurations based off different burst lengths.