Status of I2C pins and GPIOs in System OFF mode

[Akhil]

What is the status of I2C pins and GPIO pins in the System OFF mode? Do they float once the SOC enters SYSTEM OFF mode? Here the accelerometer we are using consumes high current when its I2C pins are floating. So it is critical to keep it not floating even in the SYSTEM OFF mode.

We are using softdevice 110 v8 and nRF1822 soc.

[Ole Bauck]

The gpio will keep its state in system OFF mode. The twi (i2c) pins are configured as inputs with pull-up resistor (typ. 13kohm):

#define SCL_PIN_CONF        ((GPIO_PIN_CNF_SENSE_Disabled << GPIO_PIN_CNF_SENSE_Pos)    \
                            | (GPIO_PIN_CNF_DRIVE_S0D1     << GPIO_PIN_CNF_DRIVE_Pos)   \
                            | (GPIO_PIN_CNF_PULL_Pullup    << GPIO_PIN_CNF_PULL_Pos)    \
                            | (GPIO_PIN_CNF_INPUT_Connect  << GPIO_PIN_CNF_INPUT_Pos)   \
                            | (GPIO_PIN_CNF_DIR_Input      << GPIO_PIN_CNF_DIR_Pos))

#define SDA_PIN_CONF        SCL_PIN_CONF

[Akhil]

Thank you for the prompt answser. Could you also tell me if any of these pins increase the current consumption in System OFF mode anymore than the 0.6uA System OFF current?

[Ole Bauck]

That should not cause any increase in current consumption unless the pins are pulled to ground. How much current are you experiencing in sleep? Will the current increase also happen if you don't initialize the twi?