Digital I/O Pin Behavior During Power-up Sequences

The following table represents digital I/O pin states corresponding to device power modes.

Table 1. Digital I/O Pin Behavior in Different Device States
Device state VDDIO CHIP_EN RESETN Output
driver Input
driver Pull up/down resistor (96kΩ)
Power-Down:
core supply off High Low Low Disabled (Hi-Z) Disabled Disabled
Power-on Reset:
core supply on, hard reset on High High Low Disabled (Hi-Z) Disabled Enabled
Power-On Default:

core supply on, the device is out of reset but not programmed yet

 High High High Disabled (Hi-Z) Enabled Enabled
On Sleep/
On Transmit/
On Receive:
core supply on, device
programmed by firmware High High High Programmed by firmware for each pin:
Enabled or Disabled Opposite of Output Driver state Programmed by firmware for each pin:
Enabled or
 Disabled
Parent topic: Power Consumption