External Memory Interfaces Stratix® 10 FPGA IP User Guide

ID 683741
Date 4/01/2024
Public
Document Table of Contents

3.5.2. I/O Bank Sharing

Data lanes from multiple compatible interfaces can share a physical I/O bank to achieve a more compact pin placement. To share an I/O bank, interfaces must use the same memory protocol, rate, frequency, I/O standard, and PLL reference clock signal.

Rules for Sharing I/O Banks

  • A bank cannot serve as the address and command bank for more than one interface. This means that lanes which implement address and command pins for different interfaces cannot be allocated to the same physical bank.
    Note: An exception to the above rule exists when two interfaces are configured in a Ping-Pong PHY fashion. In such a configuration, two interfaces share the same set of address and command pins, effectively meaning that they share the same address and command tile.
  • Pins within a lane cannot be shared by multiple memory interfaces.
  • Any pins in a bank which are not used by the EMIF IP can serve as general-purpose I/O pins of uncalibrated I/O standard with the same voltage settings.
  • You can configure a bank as LVDS or as EMIF, but not both at the same time.
  • Interfaces that share banks must reside at adjacent bank locations.

The following diagram illustrates two x16 interfaces sharing an I/O bank. The two interfaces share the same clock phase alignment block, so that one core clock signal can interact with both interfaces. Without sharing, the two interfaces would occupy a total of four physical banks instead of three.

Figure 15. I/O Bank Sharing