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 the 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 33. Single Parallel Termination Scheme (Class I) Using External Resistor and Memory-Side Series Resistor