
3–14
Altera Corporation
Stratix Device Handbook, Volume 2
June 2006
DDR Memory Support Overview
The DQS pins are marked in the Stratix and Stratix GX device pin table as
DQS[9..0]T
or DQS[9..0]B, where T stands for top and B for bottom.
The corresponding DQ pins are marked as DQ[9..0]T[7..0], where
[9..0]
indicates which DQS group the pins belong to. The numbering
scheme starts from right to left on the package bottom view. When not
used as DQ or DQS pins, these pins are available as user I/O pins.
You can also create a design in a mode other than the ×8, ×16, or ×32
mode. The Quartus II software uses the next larger mode with the
unused DQ pins available as regular use I/O pins. For example, if you
create a design for ×9 mode for an RLDRAM II interface (nine DQ pins
driven by one DQS pin), the Quartus II software implements a ×16 mode
with seven DQ pins unconnected to the DQS bus. These seven unused
DQ pins can be used as regular I/O pins.
1
On the top and bottom side of the device, the DQ and DQS pins
must be configured as bidirectional DDR pins to enable the DQS
phase-shift circuitry. If you only want to use the DQ and/or
DQS pins as inputs, you need to set the output enable of the DQ
and/or DQS pins to ground. Use the altdqs and altdq
megafunctions to configure the DQS and DQ pins, respectively.
However, you should use the Altera IP Toolbench to create the
data path for your memory interfaces.
Stratix and Stratix GX device side I/O banks (I/O banks 1, 2, 5, and 6)
support SDR SDRAM, ZBT SRAM, QDR SRAM, QDRII SRAM, and DDR
SDRAM interfaces and can use any of the user I/O pins in these banks for
the interface. Since these I/O banks do not have any dedicated circuitry
for memory interfacing, they can support DDR SDRAM up to 150 MHz
in -5 speed grade devices. However, these I/O banks do not support the
HSTL-18 Class II I/O standard, which is required to interface with
RLDRAM II.
Clock Pins
You can use any of the DDR I/O registers in the top or bottom bank of the
device (I/O banks 3, 4, 7, or 8) to generate clocks to the memory device.
You can also use any of the DDR I/O registers in the side I/O banks 1, 2,
5, or 6 to generate clocks for DDR SDRAM interfaces on the side I/O
banks (not using the DQS circuitry).