External Memory Interface Handbook Volume 2: Design Guidelines: For UniPHY-based Device Families

ID 683385
Date 3/06/2023
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3.2. Dual-Slot Unbuffered DDR2 SDRAM

This topic describes guidelines for implementing a dual slot unbuffered DDR2 SDRAM interface, operating at up to 400-MHz and 800-Mbps data rates.

The following figure shows a typical DQS, DQ, and DM signal topology for a dual-DIMM interface configuration using the ODT feature of the DDR2 SDRAM components.

Figure 31. Dual-DIMM DDR2 SDRAM Interface Configuration

The simulations in this section use a Stratix® II device-based board. Because of limitations of this FPGA device family, simulations are limited to 266 MHz and 533 Mbps so that comparison to actual hardware results can be directly made.