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

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

8.2.3.7. Pin Swapping Guidelines

In Agilex™ 5 devices, EMIF pin swapping is allowed under certain conditions.

Byte Lane Swapping

You can swap the data lane when the byte-lanes are utilized as DQ/DQS pins. Byte lane swapping on utilized lanes is allowed when you swap all the DQ/DQS/DM/DBI pins in the same byte lane with the other utilized byte lane.

Table 192.  LPDDR4 Byte Lane Swapping
Controller Data Width BL7 BL6 BL5 BL4 BL3 BL2 BL1 BL0
Primary

LPDDR4 x32

wDQ[3] wDQ[2] GPIO GPIO wAC1 wAC0 wDQ[1] wDQ[0]
Primary + Secondary

LPDDR4 2ch x16

sDQ[1] sDQ[0] sAC1 sAC0 wAC1 wAC0 wDQ[1] wDQ[0]

Example 1: LPDDR4 x32

BL4 and BL5 are not used by EMIF. The BL0, 1, 6 and 7 are used DQ lanes. Byte lane swapping between BL0 and BL1 is allowed; byte lane swapping between BL6 and BL7 is allowed.

Example 2: LPDDR4 2ch x16

Channel 0 uses BL0 and BL1 as the DQ lanes, and BL2 and BL3 as AC lanes. Byte lane swapping between BL0,1 is allowed.

Channel 1 uses BL6 and BL7 as the DQ lanes, and BL4 and BL5 as AC lanes. Byte lane swapping between BL6,7 is allowed.

Cross channel DQ lane swapping is not allowed.

Address and Command and CLK Lane

You cannot swap address and command and control signals in a bank. Pin mapping must adhere to the requirements defined in the table in the Address and Command Pin Placement for LPDDR4 topic.

You cannot swap address and command lanes. You cannot swap among AC0/AC1 lanes. The address and command lane placement must adhere to the specific placement defined in the table in the LPDDR4 Data Width Mapping topic.

The T and C pins for the CLK_T and CLK_C cannot be swapped with each other, nor can the T and C pins for the DQS_T and DQS_N be swapped with each other.

For guidelines on designing your PCB, refer to the EMIF PCB Routing Guidelines section in the High-Speed Signal Printed Circuit Board (PCB) Design Guidelines (HSSI, EMIF, MIPI, LVDS, PDN): Agilex 5 FPGAs and SoCs document.