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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,...
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