External Memory Interfaces Intel Agilex® 7 M-Series FPGA IP User Guide

ID 772538
Date 12/04/2023
Public

A newer version of this document is available. Customers should click here to go to the newest version.

Document Table of Contents

6.2.4.5. Specific Pin Connection Requirements

PLL

You must constrain the PLL reference clock to the address and command sub-bank only.

  • You must constrain differential reference clocks to pin indices 0 and 1 in lane AC2.
  • The sharing of PLL reference clocks across multiple interfaces is permitted; however, pin indices 0 and 1 of lane 2 of the address and command sub-bank for all slave EMIF interfaces can be used only for supplying reference clocks. Intel® recommends that you consider connecting these clock input pins to a reference clock source to facilitate greater system implementation flexibility.
Note: Intel Agilex® 7 M-Series FPGAs do not support single-ended I/O PLL reference clocks for EMIF IP.

OCT

For DDR4, you must constrain the RZQ pin to pin index 2 in lane AC2.
  • Every EMIF instance requires its own dedicated RZQ pin.
  • The sharing of RZQ pins is not permitted.

Address and Command

For DDR4, you must constrain the ALERT_N pin to the address and command lanes only.

  • In three-lane address and command schemes, you can place the ALERT_N pin at pin index 8 in lane AC2 only.
  • In four-lane address and command schemes, you can place the ALERT_N pin at pin index 8 in lane AC2 or at pin index 8 in lane AC3. When you generate the IP, the resulting RTL specifies which connection to use.

DQS/DQ/DM

For DDR4 x8 DQS grouping, the following rules apply:

  • You may use pin indices 0, 1, 2, 3, 8, 9, 10, and 11 within a lane for DQ mode pins only.
  • You must use pin index 4 for the DQS_t pin only.
  • You must use pin index 5 for the DQS_c pin only.
  • You must ensure that pin index 7 remains unused. Pin index 7 is not available for use as a general purpose I/O.
  • You must use pin index 6 for the DM/DBI_N pin only.

For DDR4 x4 DQS grouping, the following rules apply:

  • You may use pin indices 0, 1, 2, and 3 within a lane for DQ mode pins for the lower nibble only. Pin rotation within this group is permitted.
  • You must use pin index 4 for the DQS_t pin only of the lower nibble.
  • You must use pin index 5 for the DQS_c pin only of the lower nibble.
  • You may use pin indices 8, 9, 10, and 11 within a lane for the DQ mode pins only for the upper nibble.
  • Pin rotation within this group is permitted.
  • You must use pin index 6 for the DQS_t pin only of the upper nibble.
  • You must use pin index 7 for the DQS_c pin only of the upper nibble.