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Altera_Forum
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15 years ago

Cyclone III 120 & 80 have different IO drive strength

Hi all, I just found out that the Cyclone III 120 pins have full 3.3 volt IO, but when I migrated to 80 pins. I lose power IO drive strength from my pins (2.3 volt), so I couldn't run my SDRA...
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Altera_Forum
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15 years ago

What package are you using.. Are you sure all the VCCIO pins for the C80 are connected to 3.3 and not something else?

With Altera, when migrating between device you need to double check all three device IOS. Although most are identical, some pins are reserved for power/ground in particular family members while others may be NC. If you have an old IO assigned, and it's expecting it to be a VCCIO that could cause problems like you are describing. Or if it's a new board, make sure the VCCIO is actually at 3.3 instead of 2.5.

Pete