ECP5 and ECP5-5G High-Speed I/O Interface
Technical Note
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FPGA-TN-02035-1.3
63
7.7.
Planning DDR Interfaces in Clarity Designer
Once the interface is configured and connected, the placement of these modules can be planned in the Planner tab of
Clarity Designer.
The Planner allows you to drag and drop each DDR interface into the Chip View. This automatically locks the pins for
that DDR interface at the selected location. The planner takes into account all the clocking and placement
requirements, any architecture limitations for each type DDR interface. If any of the placement rules are violated, the
planner does not place the module if there are not enough resources or it places it at the next available location.
This capability allows you to plan and place all the DDR interfaces before Synthesis. The placement constraints are
carried over through the rest of the flow. Since all the design constraints are taken into account, it saves you a lot of
time to not have to run multiple iterations through the tool.
For step by step instructions on using the Planner, refer to the
shows DDR modules that are placed using Clarity Design Planner.
DDRDLL
PLL
ECLK tree
CLKDIV
DQS Group
I/O Logic
Figure 7.13. DDR Modules Paced Using Clarity Design Planner