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Altera_Forum's avatar
Altera_Forum
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18 years ago

Difference between VCCIO and VREF?

hi,everyone. i just start to use fpga cycloneIII,and i have a question which may be easy to answer. Thank you. question :is it right that VCCIO just supply the power?for example,if i want...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
17 years ago

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If you don't use SSTL/HSTL, VREF pins can be used as normal I/Os.

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Make sure you check the device handbook before doing this - I don't know about older devices, but the Stratix IV specifically states that if VREF pins are not used for voltage referencing, they cannot be used as generic I/O (Vol.1, 6-54)