Floating inputs on unused GPIO pins
Leon Woestenberg
leon.woestenberg at gmail.com
Mon Oct 13 21:08:17 EST 2008
Hello Laurent,
On Mon, Oct 13, 2008 at 11:56 AM, Laurent Pinchart
<laurentp at cse-semaphore.com> wrote:
> our hardware engineer asked me to make sure all unused GPIO pins are configured as outputs to avoid floating inputs. He got theory on his side (floating inputs can lead to higher current consumption, metastability or even permanent damage), but I'd like to ask the list for practical feedback.
>
Ideally, configure them as inputs or tri-state (both mean high
impedance), and do use pull-down or -up resistors.
Now, the answer might be different when your pins are not connected.
Check on the processor if internal pull resistors are present. If so,
use as input. If not, then your h/w engineer *may* have a point, not
sure on that though.
Regards,
--
Leon
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