Article ID: 000075447 Content Type: Troubleshooting Last Reviewed: 02/18/2014

Why can’t I merge PLLs for two different instances of the ALTMEMPHY IP?

Environment

  • PLL
  • BUILT IN - ARTICLE INTRO SECOND COMPONENT

    Critical Issue

    Description

    ALTMEMPHY calibration uses PLL reconfiguration to update PLL phases. Thus, dynamic PLL reconfiguration is required.

    Since each ALTMEMPHY interface must be calibrated separately and may require different adjustments to the PLL clocks, the PLLs cannot be merged. 

    For further information, refer to the ALTMEMPHY sections in the 12.1 version of the External Memory Interface Handbook.

    Resolution

    Related Products

    This article applies to 2 products

    Arria® II GX FPGA
    Arria® II GZ FPGA