MKE02Z: Configuration and termination for unused GPIO pins

[colin_campbell]

Hi NXP,

We are implementing an MKE02Z16VFM4 CPU based design and would like to confirm the recommended GPIO configuration and termination for unused GPIO pins (e.g. Set unused GPIO to Output Low; Set unused GPIO to Input Disabled to reduce power consumption) - the Data Sheet and Reference Manual are silent in this area?

Thanks for the guidance - CC

[colin_campbell]

Hi NXP,

Thanks for the prompt reply and the valuable reference to AN4779 - that all makes sense.

CC

[miduo]

Hello,

In general, we recommend the unused pins as output low. For unused GPIO it is recommended the following:

Do not connect unused I/O pins to anything. Make it floating, and then set it as output low in software. Periodically refresh the state of the pin to avoid changes in state by noise. If floating pins are not allowed in a particular application, connect a 10kΩ pulldown resistor for each unused pin. Do not connect any unused I/O pin to power or ground directly.

There has a useful application note for you reference:

https://www.nxp.com/docs/en/application-note/AN4779.pdf