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Altera_Forum
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12 years ago

Difference in actual VCCIO used on board and I/O standard selected in Quartus project

Hi, We have one board which uses Cyclone IV GX device. VCCIO of IO bank 3 and 4 have been connected to 1.8V and those for others have been connected to 3.3V on actual board. Unfortunately I ove...
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Altera_Forum
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12 years ago

Hi Alex,

Thank you very much for your reply.

Unfortunately we are in final stage and might not be able to change Quartus design. Still I will check and if I will be permitted, will make correction.

I have few more questions here. Do you have idea how threshold values are being calculated? I mean how FPGA decides what threshold value to be used to decide between '0' and '1'. Is it be according to I/O standard selected in Quartus pin planner ( which I think should not be )? or Is it decided based on actual VCCIO voltage connected to bank or something else? I will also check on this and will post if I find anything.

Regards,

Bhaumik