The LP87524B/J/P-Q1 device supports up to 3 GPIO signals. The GPIO signals are multiplexed with enable signals. The selection between enable and GPIO function is set with GPIOx_SEL bits in PIN_FUNCTION register. The GPIOs are mapped to EN signals so that:
When the pin is selected for GPIO function, additional bits defines how the GPIO operates:
When the GPIOx is defined as output, the logic level of the pin is set by GPIOx_OUT bit (in GPIO_OUT register).
When the GPIOx is defined as input, the logic level of the pin can be read from GPIOx_IN bit (in GPIO_IN register).
The control of the GPIOs configured to outputs can be included to start-up and shutdown sequences. The GPIO control for a sequence with ENx signal is selected by EN_PIN_CTRL_GPIOx and EN_PIN_SELECT_GPIOx bits (in PIN_FUNCTION register). The delays during start-up and shutdown are set by GPIOx_STARTUP_DELAY[3:0] and GPIOx_SHUTDOWN_DELAY[3:0] bits (in GPIOx_DELAY register) in the same way as control of the regulators.
The GPIOx signals have a selectable pulldown resistor. The pulldown resistors are selected by ENx_PD bits (in CONFIG register).
The control of the GPIOx pin cannot be changed from one ENx pin to a different ENx pin because the control is ENx signal edge sensitive. The control from ENx pin to register bit and back to the original ENx pin can be done during operation.