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Altera_Forum's avatar
Altera_Forum
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17 years ago

CIII device driving user I/O to low.

Hi all, I am using Cyclone III device and in I/O assignment, I assigned Pin L3 as INPUT and is pulled up to 3.3V with an external 20kohm pullup resistor. After reconfiguration of the device(en...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
17 years ago

Default levels for this device are 2.5V. If you are driving 2.5V you will sink current into your pin. Make sure your pull-up is really 20kohm...a smaller resistor value could result in lots of sink current. Also could be contention. Try removing the resistor and see if you can drive the output to full scale.