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Page 24
DDR3 SDRAM in Stratix III Devices Design Flow
AN 436: Using DDR3 SDRAM in Stratix III and Stratix IV Devices
© November 2008
Altera Corporation
■
15
A[14:0]
pins
■
3
BA[2:0]
pins
■
2
CK [1:0]
pins
■
2
CK#[1:0]
pins
■
11
CKE[1:0]
,
CS#[1:0]
,
RAS#
,
CAS#
,
WE#
,
ODT[1:0]
,
RESET#
,
EVENT#
pins
DQ
,
DM
,
DQS
, and
DQSn
should reside in 9 ×8 DQS groups ensuring that DQ group pin
order is maintained. The remaining 33 additional signals should be placed within the
same bank or side of the device.
1
ALTMEMPHY-based interfaces do not directly support dual rank implementations.
R
UP
and R
DN
Calibration Blocks
If calibrated series, parallel, or dynamic termination is used for the I/O in your
design, it requires a calibration block. This block requires a pair of
R
UP
and
R
DN
pins
located within the same V
CCIO
voltage bank.
This calibration block is not required to be within the same bank or side of the device
as the IOEs it is serving. However,
RUP
and
RDN
pins are typically shared with
DQ
and
DQS
pins in Stratix III devices.
DQS
and
DQSn
pins in some of the ×4 groups can also be used as
RUP
and
RDN
pins.
You cannot use a ×4 group for memory interfaces if you are using its pin members as
RUP
and
RDN
pins for OCT calibration. You may use the ×8/×9 group that includes
this ×4 group, if you are not using
DM
pins with your differential
DQS
pins.
If you fail to correctly instantiate the required number of calibration blocks for your
design, the Quartus II software automatically adds the calibration blocks during
compilation. With multiple calibration blocks, the Quartus II software does not know
which calibration blocks are associated with which blocks of logic.
If the design only requires a single calibration block, its pins are in the following
format:
termination_blk0~_rup_pad
termination_blk0~_rdn_pad
A ×8/×9 group is comprised of 12 pins, as the groups are formed by stitching two
groups of ×4 mode with 6 total pins each. A typical ×8 DDR3 SDRAM device consists
of one
DQS
, one
DQS#
, one
DM
, and 8
DQ
pins, which totals 11 pins. The two additional
RUP
and
RDN
pins cannot fit in a single ×8/×9 group, if you are using
DM
. If you are
not using the
DM
pin, only 10 of the possible 12 pins are required. So if you choose
your pin assignment carefully, you can use the 2 extra pins for
RUP
and
RDN
.
If you are using
DM
, pick different pin locations for
RUP
and
RDN
pins—for example, in
the bank that contains address and command pins.
1
You need to pick your
DQS
and
DQ
pins manually for the ×8, ×16 and ×18, or ×32 and
×36 groups, if they have pins they are using for
RUP
and
RDN
. The Quartus II software
may not place these pins correctly and may give you a no-fit.