three port RAM function

[Altera_Forum]

Is it possible to make a 3-port RAM using the memory block in EP3C25? 

  I need a 3-port RAM.of course these ports would never access the same address at the same time.  Porta is sync writable only port Portb is sync writable only port Portc is async Readable only port  porta and portb have seperate clock.

[Altera_Forum]

mux the a and b port , give the result to 2d memory(tri matrix memory) then as usual memory

[Altera_Forum]

Ho wto MUX ? Could you explain more? Thanks alot

[Altera_Forum]

--- Quote Start ---  Portc is async Readable only port  --- Quote End ---     APEX devices were the last families with RAM blocks that provided asynchronous read. All device families since then require at least the address to be registered.  Application note 210 has suggestions for using a RAM block with synchronous read in an application where you would rather have an asynchronous read.