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Altera_Forum
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14 years ago

Weak pull-up resistors

Hi everyone! I enabled weak pull-ups for the input and output pin (cyclone II device). But when I measure the voltage on these pins, on the input pin is 3V and on the output pin is 0V. Shouldn...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
14 years ago

I'm only a software engineer !

But at a previous job we had a board with quite a few separate power supplies, this caused quite a few 'back-powering' issues, especially why trying to get the main cpu into 'sleep' mode. We had to drive IO pins low (sometimes an 'active' state') before removing the power from the target.

Presumably you don't power the peripheral when the fpga in unpowered.