The ATWINC15x0-MR210xB provides programmable pull-up resistors on various pins. The purpose of these resistors is to keep any unused input pins from floating, which can cause excess current to flow through the input buffer from the VDDIO supply. These pull-up resistors must remain enabled on any unused module pin on the ATWINC15x0-MR210xB so the pin will not float. The default state at power-up is for the pull-up resistor to be enabled. However, any pin that is used must have the pull-up resistor disabled. This is because if any pins are driven to a low level while the ATWINC15x0-MR210xB is in the low power sleep state, current will flow from the VDDIO supply through the pull-up resistors, increasing the current consumption of the module. The current through any pull-up resistor that is being driven low will be VDDIO/100K because the value of the pull-up resistor is approximately 100 KΩ. For VDDIO = 3.3V, the current through each pull-up resistor that is driven low would be approximately 3.3V/100K = 33 µA. Pins that are used and have had the programmable pull-up resistor disabled must always be actively driven to either a high or low level and not be allowed to float.