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Altera_Forum
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14 years ago

Output voltage doesn't match settings

Hello! I'm using altera cyclone II DE1 EP2C20F484C7. I've set default I/O to 1.8V, set ALL I/O bank's Vccio to 1.8V. Also I'm using expansion slot. Then I have measured voltage on expansion he...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
14 years ago

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What I am doing wrong?

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You're expecting magic.

The FPGA I/O constraints must be set to match the I/O voltage (VCCIO), it does not happen the other way around.

You need to check the DE1 schematic and then match the constraints to the schematic.

Its quite possible that the board has a jumper to set the VCCIO for the GPIO header. You would also be able to find that in the schematic.

If you cannot figure out what you are looking for, post the DE1 schematic and I'll look at it for you.

Cheers,

Dave