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Example Project Walkthrough
AN 436: Using DDR3 SDRAM in Stratix III and Stratix IV Devices
© November 2008
Altera Corporation
Altera recommends you use the
Board Trace Model
assignment on all DDR3 SDRAM
interface signals. To apply board trace model assignments for the Stratix III memory
demonstration board, run the Altera-provided
S3_MB1_DDR3_BTModels.tcl
file or
manually assign virtual pin assignments using the Quartus II Pin Planner.
The Stratix III development board has the following compensation capacitors fitted to
its DDR3 SDRAM
CLK
and
CLK#
signals:
■
CLK
and
CLK#
= 7 pF (differential) compensation capacitors
These capacitors are typically fitted to designs that use nonsymmetrical DIMM
designs. You should simulate your design to see if compensation capacitors are
required. Stratix III devices have various programmable drive strength and OCT I/O
options, so compensation capacitors should not usually be required. Fitting
compensation capacitors reduces the edge rate of your signals, so you should observe
memory vendor derating guidelines.
f
For more information on compensation capacitors, refer to
Micron Technical Note
TN_47_01
.
Perform RTL or Functional Simulation (Optional)
This section describes RTL and functional simulation.
Set Up Simulation Options
To set up simulation option, follow these steps:
1. Obtain and copy the vendors memory model to a suitable location. For example,
obtain the
ddr3.v
and
ddr3_parameters.vhd
memory model files from the Micron
website and save them in the testbench directory.
1
Some vendor DIMM models do not use DM pin operation, which can cause
calibration failures. In these cases, use the vendors component models
directly.
2. Open the memory model file in a text editor and add the following define
statements to the top of the file:
DQS8
2.708
3.5p
8.3n
—
15
—
0.661
3.0p
10.7n
3p
60
Note to
:
(1) All DIMM data is preliminary and based on JEDEC R/C A (64-bit ×8 one rank DIMM). Actual DIMM is JEDEC R/C D (72-bit ×8 1 rank DIMM).
(2)
Addr
=
Addr
,
ba
,
we#
,
ras#
,
odt
,
cas
.
(3)
mem_clk
Cn value of 4.6 pF comprises 7 pF on memory demonstration board plus 2.2 pF on the DIMM, which is 9.2 pF differential or 4.6 pF
SE.
Table 7.
Stratix III Development Board Trace Model Summary
(Note 1)
Net
Near (FPGA End of Line)
Far (Memory End of Line)
Length
C_per_
length
L_per_
length
Cn
Rns
Rnh
Length
C_per_
length
L_per_
length
Cf
Rfh/Rfp