Intel® Quartus® Prime Standard Edition User Guide: Design Recommendations

ID 683323
Date 9/24/2018
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1.2.3.2. Planning FPGA Resources

Your design requirements impact the use of FPGA resources. Plan functional blocks with appropriate global, regional, and dual-regional network signals in mind.

In general, after allocating the clocks in a design, use global networks for the highest fan-out control signals. When a global network signal distributes a high fan-out control signal, the global signal can drive logic anywhere in the device. Similarly, when using a regional network signal, the driven logic must be in one quadrant of the device, or half the device for a dual-regional network signal. Depending on data flow and physical locations of the data entry and exit between the I/Os and the device, restricting a functional block to a quadrant or half the device may not be practical for performance or resource requirements.

When floorplanning a design, consider the balance of different types of device resources, such as memory, logic, and DSP blocks in the main functional blocks. For example, if a design is memory intensive with a small amount of logic, it may be difficult to develop an effective floorplan. Logic that interfaces with the memory would have to spread across the chip to access the memory. In this case, it is important to use enough register stages in the data and control paths to allow signals to traverse the chip to access the physically disparate resources needed.