8.2 Dependencies

This driver has the following dependencies:

  • Power Management

If the CPU enters a sleep mode that disables clocks used by the GPIO, the GPIO will stop functioning and resume operation after the system wakes up from sleep mode. If a peripheral function is configured for a GPIO pin, the peripheral will be able to control the GPIO pin even if the GPIO clock is stopped.
  • Clocks

The GPIO is connected to a Peripheral Bus clock (CLK_GPIO). This clock is generated by the Power Manager. CLK_GPIO is enabled at reset, and can be disabled by writing to the Power Manager. CLK_GPIO must be enabled in order to access the configuration registers of the GPIO or to use the GPIO interrupts. After configuring the GPIO, the CLK_GPIO can be disabled by writing to the Power Manager if interrupts are not used.
  • Interrupts

The GPIO interrupt request lines are connected to the NVIC. Using the GPIO interrupts requires the NVIC to be programmed first.
  • Peripheral Events

The GPIO peripheral events are connected via the Peripheral Event System.
  • Debug Operation

When an external debugger forces the CPU into debug mode, the GPIO continues normal operation. If the GPIO is configured in a way that requires it to be periodically serviced by the CPU through interrupts or similar, improper operation or data loss may result during debugging.