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Altera_Forum's avatar
Altera_Forum
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9 years ago

Cyclone III device AS Configuration

We use Cyclone III device EP3C40F780C8,configuration mode:AS Configuration (Serial Configuration Devices).

I have a question:what states of FPGA USER I/O during Configuration?

Please help me,Thank you.

1 Reply

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    9 years ago

    Hi,

    all I/O pins remain tri-stated with a weak pull-up during power-up and configuration.

    For more details, read the "Configuration Process" in section 9 of the Cyclone III Handbook, Volume I.

    Keep in mind that those "weak pull-ups" are not as weak as the name suggests; they can be as low as 7 kOhm. See "DC Characteristics" in the Cyclone III Handbook, Volume II.

    Best regards,

    GooGooCluster