Example of GPIO test in output mode

In the following example, a GPIO test is done in the output mode with Serial Wire Debug (SWD) controls.

1. Write the GPIO pins connected with drive strength H0H1:
   • For each pin, write 0x300 to the PIN_CFN register.
2. Set the GPIO pins to output mode:
   • Write 0xFFFFFFFF to the DIR register to set all pins as output.
3. Write the GPIO pins to the wanted state.

   For example:

   • Set even pins low and odd pins high by writing 0xAAAAAAAA to the OUT register.
   • Set odd pins low and even pins high by writing 0x55555555 to the OUT register.
4. Measure the voltage in the GPIO pins, for example, with an oscilloscope.
   Use a suitable load current, for example, 1 mA to verify the quality of the contact.