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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...
Altera_Forum's avatar
Altera_Forum
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15 years ago

Do you mean, that the drive strength settings (in pin planner and fitter report) are identical, but the actual strength is different? Or Quartus inforces a different setting? In the first case, you should consider, that the process variation between slow and fast corner is about 2:3 according to IBIS files. Different production lots may be near to either corner values at worst case.