Nios2 multiprocessor resource usage

The processor core uses two M4K blocks if I remember correctly for the register file. The debugger module uses one as well so you might need to go light on dedicated on-chip memories in your design. You have external memory interfaces on that board so I recommend dropping some pipeline bridges into the system if you attempt to hook up 16 processor cores to the memory otherwise the Fmax of your system will take a pretty hefty hit.