External Memory Interfaces (EMIF) IP User Guide: Agilex™ 5 FPGAs and SoCs

ID 817467
Date 11/18/2024
Public
Document Table of Contents

8.2.3.1. General Guidelines

Observe the following general guidelines when placing pins for your Intel® Agilex™ 5 external memory interface.

  1. Ensure that the pins of a single external memory interface reside on the same edge I/O.
  2. The LPDDR4 x32 or 2x16 implementation should be confined within the same I/O bank.
  3. Two different external memory interfaces cannot share a sub-bank.
  4. A byte lane must not be used by both address and command pins and data pins.
  5. The address and command pins and their associated clock pins in the address and command bank must follow a fixed pin-out scheme, as defined in the table in the Address and Command Pin Placement for LPDDR4 topic.
  6. Not every byte lane can function as an address and command lane or a data lane. The pin assignment must adhere to the LPDDR4 data width mapping defined in the LPDDR4 Data Width Mapping topic.
  7. An external memory interface can occupy one or more banks on the same edge. When an interface must occupy multiple banks, ensure that those banks are adjacent to one another. Refer to LPDDR4 Data Width Mapping for information on data width mapping.
  8. Any pin in the same bank that is not used by an external memory interface may not be available for use as a general purpose I/O pin:
    • For fabric EMIF, unused pins in an I/O lane assigned to an EMIF interface cannot be used as general-purpose I/O pins. In the same sub-bank, pins in an I/O lane that is not assigned to an EMIF interface, can be used as general-purpose I/O pins.
    • For HPS EMIF, unused pins in an I/O lane assigned to an EMIF interface cannot be used as general-purpose I/O pins. Pins in any lane in the same IO96 bank that are not assigned to an EMIF interface cannot be used as general-purpose I/O pins either.
  9. All address and command pins and their associated clock pins (CK_T and CK_C) must reside within a single sub-bank. The sub-bank containing the address and command pins is identified as the address and command sub-bank.
  10. The address and command for LPDDR4 would utilize 2 IO lanes in the sub-bank. The 2 unused I/O lane in the address and command sub-bank would serve to implement data groups. The data groups must be from the same controller as the address and command signals.
  11. An I/O lane must not be used by both address and command pins and data pins.
  12. Place read data groups according to the DQS grouping in the pin table and Pin Planner. Read data strobes (such as DQS_t and DQS_c) must reside at physical pins capable of functioning as DQS_t and DQS_c for a specific read data group size. You must place the associated read data pins (DQ), within the same group.
  13. One of the sub-banks in the device (typically the sub-bank within corner bank 3A) may not be available if you use certain device configuration schemes. For some schemes, there may be an I/O lane available for EMIF data group.
    • AVST-8 – This is contained entirely within the SDM, therefore all lanes of sub-bank 3A can be used by the external memory interface.
    • AVST-16 – Lanes 4, 5, 6, and 7 are all effectively occupied and are not usable by the external memory interface
Note: EMIF IP pin-out requirements for the Agilex™ 5 hard processor subsystem (HPS) are more restrictive than for a non-HPS memory interface. The HPS EMIF IP defines a fixed pin-out in the Quartus® Prime Pro Edition IP file (.qip), based on the IP configuration.