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ZhouTao_sf's avatar
ZhouTao_sf
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4 months ago
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How to inject a crc_error into CycloneIV device

In AN539, a crc_error can be inject into a CycloneV device, when I do the same thing on a CycloneIV device, the crc_error pin pullup, but, when I pulldown nconfig(100us) , the crc_error pin pulldown ...
  • Farabi's avatar
    Farabi
    4 months ago

    Hello,


    Unlike Cyclone V, Cyclone IV does not support in-system CRC error injection and recovery via nCONFIG pin alone. When CRC error occurs-Cyclone IV will enter configuration failure state.

    Recovery from this state will require full reconfiguration cycle.

    If CRC error remains high- consider to power cycle your board.


    regards,

    Farabi


Karen763Purvis's avatar
Karen763Purvis
Icon for New Contributor rankNew Contributor
4 months ago

Hello!

No, you can't inject a CRC error into a Cyclone IV device and then simply reload it using the nconfig pin as you would with a Cyclone V. The Cyclone V is designed with advanced, in-system self-correction features that support this, while the Cyclone IV is not. For a Cyclone IV device, a CRC error places it in a configuration failure state, which requires a full reconfiguration cycle to recover from. The nconfig pin will only trigger the device to re-enter the configuration state, requiring you to then reload the entire .sof or .rbf file to get it working again. The delay you're seeing is the device preparing for that full reload.

  • ZhouTao_sf's avatar
    ZhouTao_sf
    Icon for New Contributor rankNew Contributor
    3 months ago

    Thanks a lot!