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

ID 683385
Date 3/06/2023
Document Table of Contents
Give Feedback Reading from Memory

During read from memory, the ODT feature is turned off, thus there is no difference between using an ODT setting of 150-ohm and 75-ohm. As such, the termination scheme becomes a single parallel termination scheme (Class I) where there is an external resistor on the FPGA side and a series resistor on the memory side, as shown in the following figure.
Figure 35. Single Parallel Termination Scheme (Class I) Using External Resistor and Memory-Side Series Resistor