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Altera_Forum
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13 years ago

How to disable vrefb pins in quartus?

Hello All, I have routed a 3.3v to VREFB1N0 in cyclone IV. However,now,I am no longer needed that voltage reference. So,should I disable the voltage reference pins? If yes,how ca...
Altera_Forum's avatar
Altera_Forum
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13 years ago

The questions seems to be based on wrong assumptions.

The VREF pins are used for voltage referenced I/O standards like SSTL with DDR RAM. Their function is automatic and don't need specific assignments (of course, they must not be configured as outputs when used as a reference input). Unused Vref pins are treated similar to unused regular I/Os, sharing the global unused pin policy.

I can't imagine a reason to connect Vref to 3.3V.