External Memory Interface Handbook Volume 3: Reference Material: For UniPHY-based Device Families

ID 683841
Date 3/06/2023
Document Table of Contents

3.4.9. Arria® 10 EMIF Architecture: Clock Phase Alignment

In Arria® 10 external memory interfaces, a global clock network clocks registers inside the FPGA core, and the PHY clock network clocks registers inside the FPGA periphery. Clock phase alignment circuitry employs negative feedback to dynamically adjust the phase of the core clock signal to match the phase of the PHY clock signal.

The clock phase alignment feature effectively eliminates the clock skew effect in all transfers between the core and the periphery, facilitating timing closure. All Arria® 10 external memory interfaces employ clock phase alignment circuitry.

Figure 91. Clock Phase Alignment Illustration

Figure 92. Effect of Clock Phase Alignment