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Altera_Forum's avatar
Altera_Forum
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15 years ago

FPGA IO configed as 1.8V not working

Hi, I read from the device handbook and get that the cyclone2 devices support multi-voltage IO standards, such as 3.3/2.5/1.8/1.5 volt. I change the IO voltage to 1.5 volt in the device option...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
15 years ago

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The I/O voltage setting has the purpose of informing Quartus about the hardware enviroment. The actual voltage is set by connecting the VCCIO pins to a respective supply. Apparently your board (I guess, a development kit) has all or most VCCIO pins wired to 3.3V.

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Does the IO voltage setting have purpose other than informing quartus?

eg, if I want to use max-ii device as level shifter, but one side of the shifter's voltage is variable, you know...

so I hope the IO voltage setting has only information purpose. then i can chose one setting and change VCCIO without re-compile