Circuit design: Unused I/O pins

[sk_]

Hi,Nordic support

Circuit design: Unused I/O pins where can i found recommended I/O end terminal desing of unusing GPIO pins ? I'd need such as pull-down resistor...

Thanks.

[Håkon Alseth]

Hi,

If you have any unused GPIOs in your design, the proper way to handle these are are to disconnect the input buffer for those pins in firmware. This can be done in the PIN_CNF register, field INPUT.

Note that the reset value of all GPIOs is disconnected input buffer.

Best regards Håkon

[Bastiaan]

HI, Håkon Alseth

Thanks for your res,. OK.If i setting the input_buffer in farmware,The GPIO pin is not used and do not connect anyting in GPIO circuit design. I was concerned about noise and ESD breakdown.

thanks

[Guest]

HI, Håkon Alseth

Thanks for your res,. OK.If i setting the input_buffer in farmware,The GPIO pin is not used and do not connect anyting in GPIO circuit design. I was concerned about noise and ESD breakdown.

thanks

[mcintoda]

When input is disconnected what is the internal pull-down? Does the pull-down option assert on the inside of the disconnect switch or at the PAD that interfaces to rest of the board?