Page 6
Background
AN 436: Using DDR3 SDRAM in Stratix III and Stratix IV Devices
© November 2008
Altera Corporation
DQ and DQS Group Interface Width
For maximum performance and best skew across the interface, you should select a
device where each required memory interface can completely reside within a single
bank, or at least one side of the device.
Maximum interface width varies from device to device depending on the number of
I/Os and DQS and DQ groups available. The smallest 480-pin device sizes can
typically support a 128-MB 16-bit wide complete interface in both the top and bottom
banks and a 32-bit wide complete interface in side banks. The largest 1760-pin devices
can support a 72-bit wide DQ interface in each left and right banks. Achievable
interface width depends on the number of address and command pins that the design
requires. To ensure adequate PLL, clock and device routing resources are available,
you should always test fit any IP in the Quartus II software before PCB sign-off.
shows the number of DDR3 SDRAM suitable DQS and DQ groups available in
Stratix III devices per side.
Address and command
—
Any user I/O pin. To minimize skew, you should place
address and command pins in the same bank or side of
the device as the following pins:
■
mem_clk*
pins
■
mem_dq
,
mem_dqs
,
mem_dm
pins
Clock source
—
Dedicated PLL clock input pin with direct (not using a
global clock net) connection to the PLL and optional DLL
required by the interface.
Reset
—
Dedicated clock input pin (high fan-out signal).
Note to
:
(1) ALTMEMPHY mimic path requirement only.
Table 3.
Stratix III DDR3 SDRAM Interface Pin Utilization
(Part 2 of 2)
Pin
Pin Planner Symbol
Stratix III Pin
Table 4.
Number of DQS and DQ Groups in Stratix III Devices per Side
Package
Side
×4
×8/×9
484-pin BGA
Top and bottom
5
2
Left and right
12
4
780-pin BGA
Top and bottom
17
8
Left and right
14
6
1152-pin BGA
Top and bottom
26
12
Left and right
26
12
1517-pin BGA
Top and bottom
38
18
Left and right
34
16
1760-pin BGA
Top and bottom
44
22
Left and right
40
18
:
(1) Numbers are preliminary.
(2) Some
DQS
or
DQ
pins are dual purpose and can also be required as
RUP
,
RDN
, or configuration pins. A DQS or
DQ group is lost if you use these pins for configuration or as
RUP
or
RDN
pins for calibrated OCT. Ensure that the
DQS and DQ groups are not also required for configuration or calibrated OCT.