Article ID: 000085351 Content Type: Troubleshooting Last Reviewed: 03/07/2023

Due to a problem in the Quartus® II software version 12.1 and later, you may see this error in Stratix® V devices when using the ALTLVDS_TX megafunction in external PLL mode.

Environment

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

    Due to a problem in the Quartus® II Software version 12.1 and later, you may see this error in Stratix® V devices when using the ALTLVDS_TX mega function in external PLL mode.

     

    Error: SERDES transmitter node 'lvds_tx:lvds_tx_inst0|altlvds_tx:ALTLVDS_TX_component|lvds_tx_lvds_tx:auto_generated|outclock_tx' is not properly connected on the 'ENABLE0' port. It must be connected to one of the valid ports listed below.Info: Can be connected to LOADEN port of stratixv_pll_lvds_output WYSIWYGInfo: Can be connected to OUTCLK port of generic_pll WYSIWYG

     

     

    Resolution

    To workaround this problem, an LVDS buffer needs to be inserted between the external pll and the ALTLVDS instance on the tx_inclock and the tx_enable ports.

    Please review the article below to learn how to add an intermediate LVDS buffer between the external PLL and ALTLVDS IP.

    This problem is fixed starting with Intel® Quartus® Prime Pro Edition Software version 12.1.