Article ID: 000083582 Content Type: Troubleshooting Last Reviewed: 12/03/2012

In the 40GbE MAC and PHY IP Core, Critical Warnings are Generated when Compiling Stratix IV Device Designs

Environment

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

    Critical Issue

    Description

    Some 40GbE MAC and PHY IP Core example projects compiling Stratix IV device designs for the 12.0 release of the Quartus II software generate the following Critical Warning:

    Critical Warning: Register-to-register paths between different clock domains is not recommended if one of the clocks is from GXB receiver channel.

    The error is generated by the following projects:

    • quartus_synth\wrappers\alt_e40_phy\alt_e40_phy_siv.qpf
    • quartus_synth\example_design\alt_e40_adapter_top_siv\alt_e40_adapter_top_siv.qpf
    • quartus_synth\example_design\alt_e40_top_siv\alt_e40_top_siv.qpf

    The Critical Warning is caused by an improperly specified false path in the following .sdc files:

    • quartus_synth\wrappers\alt_e40_phy\alt_e40_phy_siv.sdc
    • quartus_synth\example_design\common\common_timing.sdc
    Resolution

    This issue is fixed in the 12.1 Quartus software release of the IP core.

    For the 12.0 release of the IP core, the Critical Warning is caused by an improperly specified false path in the following .sdc files:

    • quartus_synth\wrappers\alt_e40_phy\alt_e40_phy_siv.sdc
    • quartus_synth\example_design\common\common_timing.sdc

    In these .sdc files, the following block of code:

    if {$::TimeQuestInfo(nameofexecutable) eq "quartus_fit"} { # ok } else { set_false_path -from [get_keepers {*lane_marker_lock*vlane_num[*]} ] }

    Should be replaced with the following block of code:

    set_false_path -from [get_keepers {*lane_marker_lock*vlane_num[*]} ]

    This will prevent the Critical Warning.

    Related Products

    This article applies to 1 products

    Stratix® IV FPGAs