Altera DDR SDRAM Controller - Manual (Page 23)

Chapter 2: Getting Started 2–13
MegaWizard Plug-In Manager Design Flow
© March 2009 Altera Corporation DDR and DDR2 SDRAM Controller Compiler User Guide
1 You must enter suitable values for the pin loading, because the values affect
timing. Unsuitable values may lead to inaccurate timing analysis.
17. Enter the board trace delays. These delays are used by the timing analysis and to
configure the datapath.
1
You must accurately set the board trace delays for your system to work in
hardware.
18. Click Show Timing Estimates, at any time in the parameterize screen ), to see the
results of the system timing analysis.
19. Click the Project Settings tab.
f For more information on project settings, refer to “Project Settings” on
page 3–40 .
20. Enter the pin name of the clock driving the memory (+); enter the pin name of the
clock driving the memory (–). IP Toolbench suggests the name for the fed-back
clock input, but you can edit this name if you wish.
1 The pin names must end in [0], even if you have more than one clock pair.
1
Only change the suggested clock pin names, if you have edited the clock
pin names in the top-level design file. Changing the clock pin names
changes the names of the clock outputs and fed-back clock in the example
top-level design.
21. Ensure Update the example design file that instantiates the controller variation
is turned on, for IP Toolbench to automatically update the example design and the
testbench.
22. Altera recommends that you turn on Automatically apply datapath-specific
contraints to the Quartus II project and Automatically verify datapath-specific
timing in the Quartus II project , so that the Quartus II software automatically
runs these scripts when you compile the example design.
23. Turn off Update the example design PLLs, if you have edited the PLL and you do
not want the wizard to regenerate the PLL when you regenerate the variation.
24. The constraints script analyzes and elaborates your design to automatically extract
the hierarchy to your variation. To prevent the constraints script analyzing and
elaborating your design, turn on Enable hierarchy control, and enter the correct
hierarchy path to your variation. The hierarchy path is the path to the datapath in
your DDR SDRAM controller, without the top-level name.
Figure 2–1 on
page 2–14 shows a system example.
1
The constraints apply to the datapath (rather than the controller) so that if
you replace the controller logic with your own controller, the add
constraints script is still valid. So, if you maintain the entity and instance
names, the Quartus II software will correctly add the constraints to your
design.