In our design it is possible for 3.3V to be applied to several GPIO pins before the KL26 is powered. I believe there is a discrepancy in the KL26 datasheet regarding the presence of voltage on GPIO pins of an un-powered device.
The KL26P121M48SF4 datasheet states:
Table 4 "Voltage and current operating ratings" -- Vio(max) = VDD + 0.3V.
Table 5 "Voltage and current operating requirements" note 1 -- states there is no esd diode to VDD and no current limiting resistor is required for voltages above VSS.
I read similar questions for other Kinetis devices and believe the part is capable of safely and reliably handling voltages on un-powered device pins, but I need to be sure the same is true for the KL26.
Our device is the MKL26Z128VLL4.