Can I open multiple banks at a time in my DDR/DDR2 device through Altera High Performance DDR/DDR2 memory controller?

Description

Yes, you can have multiple banks open at a time in DDR/DDR2 High Performance memory controller.

Individually each bank will stay open until you change row address in that bank, precharge that bank, or Referesh.
 
All open banks will close if a "precharge all" command is issued, or a Referesh occurs.