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

ID 817394
Date 7/08/2024
Public
Document Table of Contents

2.3. Configuring DQ Pin Swizzling

It is important to strictly follow the pin placement for a given memory topology when assigning pin locations for your EMIF IP.

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. For example, if you implement a x32 DDR4 interface, the EMIF pin location must adhere to the x32 column in the DDR4 Pin Placement table in the Product Architecture chapter of the External Memory Interfaces (EMIF) IP User Guide: Agilex™ 5 FPGAs and SoCs . There is no flexibility to swap the address command pin location.

The following tables summarize the parameters for pin swizzling and byte swizzling, respectively.

Table 3.  User Extra Parameters for Swizzling the DQ Pin
Parameter Description
PIN_SWIZZLE_CH<m>_DQS<n>

Used for swizzling DQ pin within DQS group <n> for channel <m>.

m=0 only for DDR4.
PIN_SWIZZLE_CH<m>_ECC Used for swizzling DQ pin within the following lane:
  • ECC (When side-band ECC is enabled)
  • RUSER/WUSER lane (when Extra DQ Byte Lane is enabled)
m=0 only for DDR4
PIN_SWIZZLE_PRI_DQS<n> Used for swizzling DQ pin within DQS group <n> in the primary IO96 bank. This parameter is only applicable for lockstep configuration implemented with 2 adjacent IO96 banks.
PIN_SWIZZLE_SEC_DQS<n> Used for swizzling DQ pin within DQS group <n> in the secondary IO96 bank. This parameter is only applicable for lockstep configuration implemented with 2 adjacent IO96 banks.
PIN_SWIZZLE_PRI_ECC Used for swizzling DQ pin within the ECC lane or RUSER/WUSER lane (when the Extra DQ Byte Lane is enabled), if this lane is implemented in the primary IO96 bank. This parameter is only applicable for lockstep configuration implemented with 2 adjacent IO96 banks.
PIN_SWIZZLE_SEC_ECC Used for swizzling DQ pin within the ECC lane or RUSER/WUSER lane (when the Extra DQ Byte Lane is enabled), if this lane is implemented in the secondary IO96 bank. This parameter is only applicable for lockstep configuration implemented with 2 adjacent IO96 banks.

For device widths of x4 and x8, you can swizzle each DQ pin within its DQS group. For device widths of x16, you can swizzle each DQ pin within the lower byte and upper byte respectively. You cannot swizzle DQ pin for the lower byte to upper byte and vice versa.

Table 4.  User Extra Parameters for Byte Swizzling
Parameter Description
BYTE_SWIZZLE_CH<m>

Used for swizzling DQS group for CH<m> of the interface.

m=0 for DDR4.
BYTE_SWIZZLE_PRI Used for swizzling DQS group in the primary IO96 bank. This parameter is only applicable for lockstep configuration implemented with 2 adjacent IO96 banks.
BYTE_SWIZZLE_SEC Used for swizzling DQS group in the secondary IO96 bank. This parameter is only applicable for lockstep configuration implemented with 2 adjacent IO96 banks.