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

ID 817394
Date 4/01/2024
Public

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2.6. Pin Placement for Agilex™ 5 EMIF IP

This topic provides guidelines for pin placement.

Overview

Agilex™ 5 FPGAs have the following structure:
  • Each device contains up to 4 HSIO banks.
  • Each HSIO bank contains 2 sub-banks.
  • Each sub-bank contains 4 I/O lanes.
  • Each lane contains 12 general-purpose I/O (GPIO) pins.

General Pin Guidelines

The following are general pin guidelines.

Note: For more detailed pin information, refer to the Pin and Resource Planning section in the protocol-specific chapter for your external memory protocol, in the External Memory Interfaces (EMIF) IP User Guide: Agilex™ 5 FPGAs and SoCs .
  • Ensure that the pins for a given external memory interface reside within the same I/O row.
  • Interfaces that span multiple banks must meet the following requirements:
  • All address and command and associated pins must reside within a single sub-bank.
  • Address and command and data pins can share a sub-bank under the following conditions:
    • Address and command and data pins cannot share an I/O lane.
    • Only an unused I/O lane in the address and command bank can contain data pins.
Table 12.  General Pin Constraints
Signal Type Constraint
Data Strobe All signals belonging to a DQ group must reside in the same I/O lane.
Data Related DQ pins must reside in the same I/O lane. For protocols that do not support bidirectional data lines, read signals should be grouped separately from write signals.
Address and Command Address and Command pins must reside in predefined locations within an I/O sub-bank.

Adjacent Banks

For banks to be considered adjacent, they must reside in the same I/O row. To determine if banks are adjacent, refer to the EMIF Architecture: I/O Bank topic in the External Memory Interfaces (EMIF) IP User Guide: Agilex™ 5 FPGAs and SoCs .

Pin Assignments

To determine locations for all EMIF I/O pins you should refer to the pin table for your device. When referring to the pin table, the bank numbers, I/O bank indices, and pin names are provided.

You can perform pin assignments in a variety of ways. The recommended approach is to manually constrain some interface signals and let the Quartus® Prime Fitter handle the rest. This method consists of consulting the pin tables to find legal positions for some of the interface pins and assigning them through the .qsf file that is generated with the EMIF design example. For this method of I/O placement, you must constrain the following signals:

  • RZQ pin
  • PLL reference clock
  • Memory reset

Based on the above constraints, the Quartus® Prime Fitter rotates pins within each lane as necessary.

Do not change the location for the EMIF pin using a .qsf assignment or the Pin Planner if you need to swap the DQ pins within a DQS group or the DQS group to simplify board design.

Refer to the Configuring DQ Pin Swizzling topic in this section, for more information about how to swap the DQ pin and DQS group.