The maximum clock frequency that can be used with the internal oscillator is 12 MHz. However, it's recommended to use a crystal oscillator for frequencies above 4 MHz for better accuracy and stability.
The pin multiplexing can be configured using the PINSELx registers. Each peripheral function has a specific pin multiplexing setting, which can be found in the datasheet or the user manual. The PINSELx registers need to be programmed accordingly to enable the desired peripheral function on a specific pin.
The minimum voltage required for the ADC to operate correctly is 2.4 V. However, it's recommended to use a voltage of at least 2.7 V for optimal performance.
To implement a watchdog timer reset, the WDT should be enabled by setting the WDEN bit in the WDTMOD register. The watchdog timer can be fed by writing a specific value to the WDTFEED register. If the watchdog timer is not fed within the timeout period, a reset will be generated.
The maximum current that can be sourced or sunk by a GPIO pin is 4 mA. However, it's recommended to limit the current to 2 mA or less to ensure reliable operation and to prevent overheating.