Stratix II and M4K true dual port memory

There are only two addresses on each RAM, so only a single dual-port is possible. Depending on your clock frequency, you could time-share these resources, i.e. run a 2x clock to them and toggle back and forth between them. Might require some extra pipelining, but usually not a big deal with DSP resources. I don't know if there's a way to do that directly in DSP Builder though(which is probably a problem if the M4Ks come out of larger functions). Are you using the M512s too?