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Altera_Forum
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16 years ago

False high inputs

Using a Cyclone II 2C20F484C7 fpga, and having some trouble with false high inputs. Basically if I have a switch connected, in other words an open line, it seems to default to reading it as a h...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
16 years ago

he means if you have a switch that is normally open, and when it is closed it connects to VCC, you will need to disable the internal pullup resistor and use an external pulldown resistor (so that the pin reads 0 when the switch is open). alternatively you can connect the switch to GND, and enable the pullup resistor which will require no external components. adjust accordingly in your HDL.