Internal pin pull-ups

Internal pull-up/down resistors only apply to GPIO lines that are configured as disabled (0) or digital input (3). Use PR (Pull-up/Down Resistor Enable) to enable them on a per-pin basis and use PD (Pull Up/Down Direction) to determine the direction.

Internal pin pull-ups can pull excess current and cause the sleep current readings to be higher than desired if you drive or float the pull-ups.

• Disable all pull-ups for input lines that have a low driven state during sleep.
• Enable pull-ups for floating lines or inputs that do not connect to other circuitry.

If you use an analog-to-digital converter (ADC) to read the analog voltage of a pin, it may not be possible to stop all leakage current unless you can disconnect the voltage during sleep. Each floating input that is not at a valid high or low level can cause leakage depending on the temperature and charge buildup that you may not observe at room temperature.