Article ID: 000084716 Content Type: Troubleshooting Last Reviewed: 09/11/2012

Why does Quartus II assigns incorrect I/O standard for the refclk pin on Arria II GX/GZ and Stratix IV GX/GT devices for ALTGX instances?

Environment

  • Quartus® II Subscription Edition
  • BUILT IN - ARTICLE INTRO SECOND COMPONENT
    Description

    Quartus® II incorrectly assigns I/O standard for the refclk pin on Arria® II GX/GZ and Stratix® IV GX/GT devices for ALTGX instances, if you do not manually assign the correct refclk I/O standard for the pll_inclk port.  Quartus II auto-assigns the general default I/O standard set by user in the design. This leads to an incorrect setting of the I/O standard of 2.5V to the REFCLK pin.

    Resolution

    Manually assign the correct refclk IO standard for the pll_inclk pin. 

     

    This issue will be fixed in future Quartus II release.

    Related Products

    This article applies to 3 products

    Arria® II GX FPGA
    Arria® II GZ FPGA
    Stratix® IV FPGAs