Hello,
The RAM area mentioned is for "internal" memory.
If you wish to add external RAM, you will therefore address in the EXTERNAL SPACE.
Note that the XGATE cannot access external space.
The ALIGN 2 is only necessary when XGATE can access the area because XGATE can only do ALIGNED 16-BIT accesses, while the CPU can do mis-aligned accesses.
Therefore, when you declare your external RAM in the external space, you will not be able to access it from the XGATE and will not need the ALIGN in the prm. This will save you space if you store 8-Bit variables (for instance).
Alban.