Forum Discussion

Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
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
18 years ago

You can omit VREF pins if you are not using any voltage referenced IO standard. In this case you can use VREF pins just like any other IO. VCCIO is the main supply lines, which must be tied to the supply voltage, which is the expected IO supply, e.g., Connect 3.3V to VCCIO for 3.3V IO (using a 3.3V device).