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Altera_Forum
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14 years ago

DE III problem witch Voltage of the I/O pins

Hi. I’m developing a project in the DE3 and I’m having a problem with the voltage of the GPIO Pins. To describe my application, It consists basically of use the switches and the dipswitches to ...
Altera_Forum's avatar
Altera_Forum
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14 years ago

I guess the lower voltage on GPIO probably means you have some design issue in the connections outside fpga. For example another signal is driving gpio or excessive current is being drawn from fpga output.

Are gpios connected to anything?

Can you also check gpio with an oscilloscope? Maybe the signal is not stable, because some switches configurations introduce an abnormal modulation; since the multimeter is slow, it measures the mean value and you simply see a lower voltage.